Modular minimally invasive tubular retractor

Abstract

A modular and / or telescoping tubular retractor designed for minimally invasive spinal surgeries features a proximal end assembly with removable shims, allowing for access windows along its length. The retractor includes an adjustable distal end assembly with telescoping or extendable segments to accommodate various surgical depths. Its distal tip is shaped to contact tissue surrounding the surgical site, and the retractor's length can be adjusted during or before surgery. The system also includes a method for performing surgeries using the retractor, emphasizing its adaptability and precision in accessing surgical sites while minimizing tissue damage.

Description

PCT ApplicationDocket No.: 408477-502001 WOMODULAR MINIMALLY INVASIVE TUBULAR RETRACTORCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to United States (US) provisional application Serial No. 63 / 697,352, filed 20-September-2024, the entire disclosure of which is incorporated by reference as if fully set forth herein in its entirety. This application also claims the benefit of priority to US provisional application Serial No. 63 / 798,513, filed 01 -May-2025, the entire disclosure of which is incorporated by reference as if fully set forth herein in its entirety.FIELD OF THE INVENTION

[0002] The embodiments of the present invention relate to intelligently designed surgical retractors and, in particular, surgical retractors that can be utilized for spine surgeries.BACKGROUND OF THE INVENTION

[0003] Minimally invasive spinal surgeries have gained significant traction in recent years due to their potential to reduce recovery times, minimize scarring, and decrease the risk of complications compared to traditional open surgeries. These procedures require precise and efficient tools to access the spinal area while minimizing disruption to surrounding tissues. Traditional retractors used in open surgeries are often too large and cumbersome for minimally invasive techniques, necessitating the development of specialized instruments that can provide adequate access and visibility while maintaining a small surgical footprint.

[0004] The history of minimally invasive surgeries dates back several decades, with the evolution of techniques and instruments that have revolutionized the field of surgery. The concept of minimally invasive surgery (MIS) began to take shape in the 20th century, with the development of endoscopic techniques. The introduction of laparoscopy in the early 1900s marked a significant milestone, allowing surgeons to perform procedures through small incisions using a camera and specialized instruments. This approach minimized trauma to the body and led to faster recovery times, setting the stage for the broader adoption of MIS across various surgical disciplines.

[0005] As technology advanced, so did the capabilities of minimally invasive techniques. The 1980s and 1990s saw a surge in the popularity of laparoscopic surgeries, particularly in the fields of gynecology and general surgery. The benefits of reduced postoperative pain, shorter hospital stays, and quicker return to normal activities became increasingly evident, driving further innovation and refinement of MIS techniques. The development of robotic-assisted surgery in the late 20th century further expanded the possibilities of minimally invasivePCT ApplicationDocket No.: 408477-502001 WO procedures, offering enhanced precision and control through robotics and robotic aided surgeries.

[0006] The history of retractors, essential tools in both open and minimally invasive surgeries, is equally rich and varied. Retractors have been used for centuries to hold back tissues and provide access to surgical sites. Early retractors were simple, manually operated devices, often crafted from materials like wood or metal. As surgical techniques evolved, so did the design and functionality of retractors. The 19th and 20th centuries saw significant advancements in retractor technology, with the introduction of self-retaining retractors that allowed surgeons to maintain a clear view of the operative field without the need for manual assistance.

[0007] Spinal retractors, specifically designed for spinal surgeries, have undergone significant evolution to meet the demands of both open and minimally invasive procedures. Traditional spinal retractors were often large and cumbersome, designed to provide maximum exposure during open surgeries. However, the shift towards minimally invasive spinal techniques necessitated the development of retractors that could offer the same level of access and visibility while minimizing tissue disruption. This led to the creation of specialized spinal retractors, such as metal tubular retractors, which are designed to provide a small surgical footprint and allow for precise access to the spinal area.

[0008] The history of minimally invasive surgeries and the evolution of retractors highlights the continuous advancements in surgical technology aimed at improving patient outcomes. The development of specialized instruments, such as tubular retractors for minimally invasive spinal surgeries, underscores the importance of innovation in addressing the challenges of modern surgical techniques. As the demand for minimally invasive procedures continues to grow, the ongoing refinement and development of surgical tools will play a crucial role in shaping the future of surgery. What is urgently needed at the present time are surgical retractors that allow for improvisation before or during surgery to accommodate specific surgical conditions that cannot be easily foreseen when the surgical retractor or a kit containing the retractors is acquired.BRIEF SUMMARY OF THE INVENTION

[0009] The following presents a simplified summary of the innovation in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is intended to neither identify key or critical elements of the invention nor delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.PCT ApplicationDocket No.: 408477-502001 WO

[0010] According to some aspects, the challenge in minimally invasive spinal surgeries lies in achieving the delicate balance between providing sufficient access to the surgical site and minimizing the incision size. One problem addressed by the present disclosure is that surgeons require retractors that can be easily adjusted to accommodate different patient anatomies and surgical depths, all while ensuring stability and safety during the procedure. The technology herein recognizes that the need for innovative solutions that address these challenges is critical, as the demand for minimally invasive techniques continues to grow, driven by patient preference and advancements in surgical technology.

[0011] The development of the tubular retractors for minimally invasive spinal surgeries herein represents a significant advancement in the field. These retractors are designed to be adjustable, allowing surgeons to customize the length and shape of the retractor to suit the specific needs of the procedure. The use of telescoping, additive or extendable segments enables the retractor to be lengthened or shortened as needed, providing flexibility and adaptability during surgery. Additionally, the incorporation of removable shims allows for the creation of surgical access windows, further enhancing the versatility of the retractor.

[0012] A major problem is that tubular retractors for use in minimally invasive spinal surgeries do not provide removable shims that a surgeon can remove to make surgical windows to place instruments into during or before a surgery and that tubular retractors are not adjustable in length for deeper or for shallower surgeries thus, surgeons cannot adjust tubular retractors before or during surgeries and must use unadjustable tubular retractors that often do not fit the patient or the exact surgical site.

[0013] In some embodiments, the technology includes a tubular retractor for use in minimally invasive spinal surgeries comprising: a main tube with a collar at the proximal end and an extendable distal end; wherein the main tube and the collar comprise one or more removable shims that when removed either during or prior to a surgery will provide one or more surgical access windows each from the proximal collar running along the length of the main tube; and wherein the extendable distal end comprises one or more extendable segments configured to lengthen and / or shorten the tubular retractor for deeper or shallower surgeries and the far distal end of the one or more extendable segments is configured to provide a beveled, contoured or cylindrical shape for contact with the tissue surrounding a surgical site; wherein the tubular retractor is configured to be adjusted in length either during or prior to a surgery.

[0014] Keeping in mind possible combination devices and the above introduction, as an additional brief summary or to provide discussion points for a brief summary, some example features of the technology disclosed herein can be briefly summarized by the following list of features, any of which can be inter-combined or discussed with any other feature, Figure, Drawing, detail, wording, embodiment, aspect, or example disclosed herein:PCT ApplicationDocket No.: 408477-502001 WO

[0015] Feature 1 : A tubular retractor for minimally invasive spinal surgeries, comprising: a proximal end assembly comprising removable shims, wherein removal of the removable shims provides access windows running along a length of the tubular retractor; an adjustable distal end assembly comprising telescoping or extendable segments configured to lengthen or shorten the tubular retractor for accommodating different surgical depths; and a distal tip configured to provide a beveled, contoured or cylindrical shape for contacting tissue surrounding a surgical site; wherein the tubular retractor is adjustable in length either during or prior to a surgery.

[0016] Feature 2: The tubular retractor of feature 1 , wherein the proximal end assembly comprises a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims.

[0017] Feature 3: The tubular retractor of feature 2, wherein the access windows extend from the collar along the length of the main tube when the removable shims are removed.

[0018] Feature 4: The tubular retractor of feature 1 , wherein the removable shims are configured to be removed either during or prior to the surgery to provide the access windows.

[0019] Feature 5: The tubular retractor of feature 1 , wherein the adjustable distal end assembly comprises one or more telescoping segments.

[0020] Feature 6: The tubular retractor of feature 1 , wherein the adjustable distal end assembly comprises one or more extendable segments.

[0021] Feature 7: The tubular retractor of feature 1 , wherein the distal tip is at a far distal end of the adjustable distal end assembly.

[0022] Feature 8: The tubular retractor of feature 1 , wherein the distal tip is configured to provide the beveled shape for contacting the tissue surrounding the surgical site.

[0023] Feature 9: The tubular retractor of feature 1 , wherein the distal tip is configured to provide the contoured shape for contacting the tissue surrounding the surgical site.

[0024] Feature 10: The tubular retractor of feature 1 , wherein the distal tip is configured to provide the cylindrical shape for contacting the tissue surrounding the surgical site.

[0025] Feature 11 : The tubular retractor of feature 1 , wherein the tubular retractor is made of at least one of stainless steel, titanium, aluminum, plastic, polymer, ceramic, composite material, carbon fiber, glass, Polyetherimide (PEI), Polyphenylsulfone (PPSLI), Polysulfone (PSU), Polyetheretherketone (PEEK), Polyaryletherketone (PAEK), Polyetherketoneketone (PEKK), Polyetherketone (PEK), Polyetherketoneetherketoneketone (PEKEKK), or any combination thereof.

[0026] Feature 12: A method of performing minimally invasive spinal surgery, comprising: providing a tubular retractor comprising a proximal end assembly with removable shims, an adjustable distal end assembly, and a distal tip; adjusting a length of the tubular retractor by lengthening or shortening the adjustable distal end assembly; removing the removable shimsPCT ApplicationDocket No.: 408477-502001 WO from the proximal end assembly to provide access windows running along a length of the tubular retractor; and contacting tissue surrounding a surgical site with the distal tip, the distal tip having a beveled, contoured or cylindrical shape.

[0027] Feature 13: The method of feature 12, wherein adjusting the length of the tubular retractor comprises lengthening or shortening the adjustable distal end assembly to accommodate a depth of the surgical site.

[0028] Feature 14: The method of feature 12, wherein removing the removable shims comprises removing the removable shims either during or prior to the surgery.

[0029] Feature 15: The method of feature 12, wherein the proximal end assembly comprises a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims.

[0030] Feature 16: The method of feature 15, wherein the access windows extend from the collar along the length of the main tube when the removable shims are removed.

[0031] Feature 17: The method of feature 12, wherein the adjustable distal end assembly comprises one or more telescoping segments.

[0032] Feature 18: The method of feature 12, wherein the adjustable distal end assembly comprises one or more extendable segments.

[0033] Feature 19: The method of feature 12, wherein the distal tip is at a far distal end of the adjustable distal end assembly.

[0034] Feature 20: The method of feature 12, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the beveled shape of the distal tip.

[0035] Feature 21 : The method of feature 12, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the contoured or cylindrical shape of the distal tip.

[0036] Feature 22: A system for performing minimally invasive spinal surgeries, comprising: a tubular retractor comprising a main tube having a collar at one end and an extendable distal end, wherein the main tube and the collar comprise one or more removable elements that, when removed at any time, provide one or more access windows from the collar running along a length of the main tube; and wherein the extendable distal end comprises one or more adjustable segments configured to adjust a length of the tubular retractor for varying depths, and wherein a distal end of the one or more adjustable segments is configured to provide a suitable shape for contact with surrounding tissue; and one or more mount arms affixed to the collar, wherein the one or more mount arms are configured to be mounted to a surgical table.

[0037] Feature 23: The system of feature 22, wherein the collar is located at a proximal end of the main tube.PCT ApplicationDocket No.: 408477-502001 WO

[0038] Feature 24: The system of feature 22, wherein the one or more removable elements comprise one or more removable shims.

[0039] Feature 25: The system of feature 22, wherein the one or more access windows extend from the collar to the extendable distal end and / or extend from the collar along the length of the main tube.

[0040] Feature 26: The system of feature 22, wherein the one or more adjustable segments comprise at least one of telescoping segments or extendable segments.

[0041] Feature 27: The system of feature 22, wherein the length of the tubular retractor is adjustable for deeper or shallower surgeries.

[0042] Feature 28: The system of feature 22, wherein the length of the tubular retractor is adjustable either during or prior to a surgery.

[0043] Feature 29: The system of feature 22, wherein the suitable shape of the distal end of the one or more adjustable segments comprises at least one of a beveled shape, a contoured shape, or a cylindrical shape.

[0044] Feature 30: The system of feature 22, wherein the distal end of the one or more adjustable segments is configured to minimize tissue damage.

[0045] Feature 31 : A kit for performing minimally invasive spinal surgeries, the kit comprising: a tubular retractor for minimally invasive spinal surgeries, the tubular retractor comprising: a proximal end assembly comprising removable shims, wherein removal of the removable shims provides access windows running along a length of the tubular retractor; an adjustable distal end assembly comprising telescoping or extendable segments configured to lengthen or shorten the tubular retractor for accommodating different surgical depths; and a distal tip configured to provide a beveled, contoured or cylindrical shape for contacting tissue surrounding a surgical site; wherein the tubular retractor is adjustable in length either during or prior to a surgery.

[0046] Feature 32: The kit of feature 31 , wherein the removable shims are configured to be removed at any time to provide the access windows.

[0047] Feature 33: The kit of feature 31 , wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor for deeper or shallower surgeries.

[0048] Feature 34: The kit of feature 31 , wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor either during or prior to a surgery.

[0049] Feature 35: The kit of feature 31 , wherein the distal tip is configured to minimize tissue damage when contacting the tissue surrounding the surgical site.

[0050] Feature 36: The kit of feature 31 , further comprising instructions for using the tubular retractor to access a surgical site through the access windows.PCT ApplicationDocket No.: 408477-502001 WO

[0051] Feature 37: The kit of feature 31 , wherein the proximal end assembly further comprises a collar, and wherein the access windows extend from the collar to the adjustable distal end assembly.

[0052] Feature 38: The kit of feature 37, wherein the collar is located at a proximal end of the tubular retractor.

[0053] Feature 39: The kit of feature 31 , wherein the telescoping or extendable segments of the adjustable distal end assembly are configured to be adjusted during a minimally invasive spinal surgery to accommodate changes in surgical depth.

[0054] Feature 40: The kit of feature 31 , further comprising one or more surgical instruments configured to be inserted through the access windows to perform the minimally invasive spinal surgery.

[0055] Feature 41 : The kit of feature 31 , wherein the tubular retractor is configured to be mounted to a surgical table using one or more mount arms attached to the proximal end assembly.

[0056] The older retractor technologies do not guide a precision surgery to an optimum outcome, and instead, place a huge burden on the surgeon to make critical decisions during the surgery with a retractor that might not actually fit the surgical site. In a broad embodiment, the technology herein provides a retractor system that is intelligently thought out and planned to provide a precision surgical outcome. According to some aspects, methods are provided herein wherein a surgeon can adjust a retractor mid-surgery to ensure the retractor is a fit for a surgical site. Thus, the technology herein saves lives and improves surgical outcomes.

[0057] In some embodiments, the retractors disclosed herein can include markings on the retractors. According to some aspects, the markings guide the surgeon to an exact surgical site or an exact discectomy site, where to insert a spinal cage, and how deep to insert. According to some aspects, the retractor systems include interlocking or contacting extensions, interlocking pieces, telescoping pieces, threaded pieces and / or extendable wings.

[0058] As will be discussed in more detail below, the technology disclosed herein solves many of the larger problems in spinal surgeries and in discectomy surgeries.

[0059] Other implementations are also described and recited herein. These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of aspects as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Solely for the purpose of illustration, certain embodiments of the present invention arePCT ApplicationDocket No.: 408477-502001 WO explained using examples in the drawings described below. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and configurations shown. In the drawings:

[0061] FIG. 1 shows a perspective view of a modular minimally invasive tubular retractor 110.

[0062] FIG. 2 provides an expanded view of a modular minimally invasive tubular retractor illustrating that the entire extendable pieces can be telescoping or can include locking mechanisms or first threaded fitting, second threaded fitting, third threaded fitting, fourth threaded fitting, and additional threads or snap fasteners as needed for additional extension pieces. Any of the threads can be snap fittings, locking and / or telescoping fittings or any fitting suitable for adjustable surgical devices.

[0063] FIG. 3 shows a rotating beveled tip 145 that can accommodate specific surgical sites.

[0064] FIG. 4A illustrates how the double bevel distal piece can take different shapes than the bevel distal piece shown in FIG. 3. FIG. 4B shows a drawing of the double bevel distal piece 155 on a modular minimally invasive tubular retractor 110 or a modular 3-shim tubular retractor 111 (the retractors herein can have any number of shims and / or mount arms).

[0065] FIG. 5 illustrates a double slant distal piece.

[0066] FIG. 6 illustrates a cylindrical end distal piece.

[0067] FIG. 7 illustrates how the first removable shim can be removed to provide a first surgical access window and the second removable shim can be removed to provide a second surgical access window; there can be any number of removable shims.

[0068] FIG. 8 shows a surgeon's view of the main tube with the mount arms removed and the removable shims removed to show the first surgical access window and the second surgical access window.

[0069] FIG. 9A illustrates how stability can be provided by a first shim lock 315, a second shim lock 320, a third shim lock 335, and a fourth shim lock 340. FIG. 9B illustrates how a third removable shim 355 can be utilized with a first mount arm 280 (the retractors herein can have any number of removable shims as needed and the mount arms are optional and / or can be provided in additional arms).

[0070] FIG. 10 is a flowchart illustrating a method comprising steps for providing a tubular retractor for minimally invasive spinal surgeries, according to an embodiment.

[0071] FIG. 11 illustrates aspects of a tubular retractor system 200 including the removable shims, which may be integral to the tubular retractor system for minimally invasive spinal surgeries.

[0072] FIG. 12A shows a tubular retractor 500 for use in a spinal surgery (prior art).

[0073] FIG. 12B (prior art) shows the tubular retractor 500 inserted into soft tissue 535 so that the distal opening 517 contacts a target tissue 540 for the surgery.PCT ApplicationDocket No.: 408477-502001 WO

[0074] FIG. 13A shows a sliding access tubular retractor 600 including a windowed insertion tube 615 with a first sliding window 625 and a second sliding window 630 (in back).

[0075] FIG. 13B illustrates how a first side tool 300 and a second side tool 400 can be inserted through the first sliding window 625 and the second sliding window 630 to allow side access to a target surgical area.

[0076] FIG. 14 shows a side view of a modular minimally invasive tubular retractor 110 with a first dilator (non-cannulated) 405, a second dilator (cannulated) 410 and a third dilator (cannulated) 415. FIG. 15 shows a side view of a first dilator (non-cannulated) 405 with an attachment handle 407 and a working tip of the first dilator 406. FIG. 16 shows a second dilator 410 removed from the third dilator 415. FIG. 17 depicts the third dilator (cannulated) 415 with its working handle 417.

[0077] FIG. 18A shows keyed coupling at the rotating distal bevel. FIG. 18B illustrates engagement, disengagement, and tactile indexing.

[0078] FIG. 19 illustrates the top slot 450 and accessory ecosystem.

[0079] FIG. 20 illustrates some non-limiting working angles at a target site.

[0080] FIG. 21 shows an exploded distal-end assembly an enlarged orientation pin 435 view at actual and an enlarged size.

[0081] It should be understood that while different numbers / numbering could be sometimes used in some of the figures above to describe different embodiments and different aspects of the technology, any number from any figure can be inter-combined with a numbered aspect from any other figures. All trademarks, images, likenesses, words, and depictions in the drawings and the disclosure are plainly in fair use and are provided solely for the purposes of illustration of the invention in view of an urgent need to treat subjects as further discussed in detail below.DETAILED DESCRIPTION OF THE INVENTION

[0082] The subject innovation is now described in some instances, when necessary, with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It may be evident, however, that the present invention may be practiced without these specific details. In other instances, well-known structures, methods, and devices are shown in block diagram form or with illustrations in order to facilitate describing the present invention. It is to be appreciated that certain aspects, modes, embodiments, variations and features of the invention are described below in various levels of detail in order to provide a substantial understanding of the present invention.DEFINITIONS

[0083] For convenience, the meaning of some terms and phrases used in the specification,PCT ApplicationDocket No.: 408477-502001 WO examples, and appended claims, are provided below. Unless stated otherwise, or implicit from context, the following terms and phrases include the meanings provided below. The definitions are provided to aid in describing particular embodiments, and are not intended to limit the claimed invention, because the scope of the invention is limited only by the claims. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is an apparent discrepancy between the usage of a term in the art and its definition provided herein, the definition provided within the specification shall prevail. In general, typical chemical terminology is found in the International Union of Pure and Applied Chemistry GoldBook1. This disclosure is purposefully presented in commonly understood words, known to a person of skill in the art, but Merriam-Webster’s Online Dictionary is used, when appropriate, for terms not specifically demonstrated herein or not known in the art2.

[0084] As used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the content clearly dictates otherwise. For example, reference to "a cell" includes a combination of two or more cells, and the like.

[0085] As used herein, the term "approximately" or "about" in reference to a value or parameter are generally taken to include numbers that fall within a range of 5%, 10%, 15%, or 20% in either direction (greater than or less than) of the number unless otherwise stated or otherwise evident from the context (except where such number would be less than 0% or exceed 100% of a possible value). As used herein, reference to "approximately" or "about" a value or parameter includes (and describes) embodiments that are directed to that value or parameter. For example, description referring to "about X" includes description of "X".

[0086] As used herein, the term “or” means “and / or.” The term "and / or" as used in a phrase such as "A and / or B" herein is intended to include both A and B; A or B; A (alone); and B (alone). Likewise, the term "and / or" as used in a phrase such as "A, B, and / or C" is intended to encompass each of the following embodiments: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0087] As used herein, the term "comprising" means that other elements can also be present in addition to the defined elements presented. The use of "comprising" indicates inclusion rather than limitation. The term “including” can be interchanged with “comprising”.

[0088] The term "consisting of" refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment.

[0089] As used herein the term "consisting essentially of" refers to those elements required for a given embodiment. The term permits the presence of additional elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment of thePCT ApplicationDocket No.: 408477-502001 WO invention. The term “consisting essentially of” can also be exemplified by plain language provided in the claims.

[0090] The term "statistically significant" or "significantly" refers to statistical significance and generally means a two-standard deviation (2SD) or greater difference.

[0091] As used herein, the term "subject" refers to a mammal, including but not limited to a dog, cat, horse, cow, pig, sheep, goat, rodent, or primate. Subjects can be house pets (e.g., dogs, cats), agricultural stock animals {e.g., cows, horses, pigs, chickens, etc.), laboratory animals {e.g., mice, rats, rabbits, etc.), but are not so limited. Subjects particularly include human subjects in urgent treatment as described herein. The human subject may be a pediatric, adult, or a geriatric subject. The human subject may be of any sex.

[0092] The term “treating” includes prophylactic and / or therapeutic treatments. The term “prophylactic or therapeutic” treatment is art-recognized and includes administration to the host of one or more of the subject compositions and / or application of one or more therapies or surgeries. If this is done prior to clinical manifestation of the unwanted condition e.g., disease or other unwanted state of the host animal) then the treatment is prophylactic {i.e., it protects the host against developing the unwanted condition), whereas if it is administered after manifestation of the unwanted condition, the treatment is therapeutic, i.e., it is intended to diminish, ameliorate, or stabilize the existing unwanted condition or side effects thereof).

[0093] As used herein, the terms “treat,” “treatment,” “treating,” or “amelioration” when used in reference to a disease, disorder, or medical condition, refer to therapeutic surgeries or treatments for a condition, wherein the object is to reverse, alleviate, ameliorate, inhibit, slow down or stop the progression or severity of a symptom or condition. The term “treating” includes reducing or alleviating at least one adverse effect or symptom of a condition. Treatment is generally “effective” if one or more symptoms or clinical markers are reduced. Alternatively, treatment is “effective” if the progression of a condition is reduced or halted. That is, “treatment” includes not just the improvement of symptoms or markers, but also a cessation or at least slowing of progress or worsening of symptoms that would be expected in the absence of treatment. Beneficial or desired clinical results include, but are not limited to, alleviation of one or more symptom(s), sign(s), diminishment of extent of the deficit, stabilized {i.e., not worsening) state of a symptom or condition, delay or slowing of onset of symptoms or indications, and an increased lifespan as compared to that expected in the absence of treatment.

[0094] The terms: “decrease”, “reduced”, “reduction”, or “inhibit” are all used herein to mean a decrease by a statistically significant amount. In some embodiments, “reduce,” “reduction" or “decrease" or “inhibit” typically means a decrease by at least 10% as compared to a reference level {e.g., the absence of a given treatment or agent) and can include, for example, a decrease by at least about 10%, at least about 20%, at least about 25%, at least about 30%,PCT ApplicationDocket No.: 408477-502001 WO at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99% , or more. As used herein, “reduction” or “inhibition” does not encompass a complete inhibition or reduction as compared to a reference level. “Complete inhibition” is a 100% inhibition as compared to a reference level. A decrease can be preferably down to a level accepted as within the range of normal for an individual without a given disorder.

[0095] In some embodiments, the decrease in the one or more signs or symptoms is evaluated according to a specialized healthcare provider. In some embodiments, signs are observed or measured by a health care provider. Symptoms can be reported by the subject. In some embodiments, the decrease of signs or symptoms occurs in less than about 120 days, 90 days, less than about 60 days, less than about 30 days, less than about 15 days, less than about 10 days, or less than about 5 days, or less than about 3 days, or less than about 1 day. In some embodiments, the decrease of signs or symptoms occurs in less than 1 day, less than 1 week, less than 1 month, or in less than 1 year.

[0096] The terms “increased”, “increase”, “enhance”, or “activate” are all used herein to mean an increase by a statistically significant amount. In some embodiments, the terms “increased”, “increase”, “enhance”, or “activate” can mean an increase of at least 10% as compared to a reference level, for example an increase of at least about 20%, or at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90% or up to and including a 100% increase or any increase between 10-100% as compared to a reference level, or at least about a 2-fold, or at least about a 3-fold, or at least about a 4-fold, or at least about a 5-fold or at least about a 10-fold increase, or any increase between 2-fold and 10-fold or greater as compared to a reference level. In the context of a marker or symptom, an “increase” is a statistically significant increase in such level.

[0097] As used herein, an agent or a therapeutic agent provided to a subject and suspected to be or involved in a treatment can be a small molecule less than 1000 MW or a large molecule not less than 1000 MW including biologies, oligonucleotides, peptides, oligosaccharides, and larger molecules. Any therapeutic agents disclosed herein can be used as or in combination with small molecules and / or large molecules as discussed herein.

[0098] A subject can be one who has been previously diagnosed with or identified as suffering from or having a condition in need of treatment {e.g., a spinal nerve compression, pain, weakness, numbness, tingling, a bone spur, arthritis, or a related disorder) or one or more complications related to such a condition, and optionally, but need not have already undergone treatment for a condition or the one or more complications related to the condition. Alternatively, a subject can also be one who has not been previously diagnosed as having aPCT ApplicationDocket No.: 408477-502001 WO condition in need of treatment or one or more complications related to such a condition. For example, a subject can be one who exhibits one or more risk factors for a condition, or one or more complications related to a condition or a subject who does not exhibit risk factors. A “subject in need” of treatment for a particular condition can be a subject having that condition, diagnosed as having that condition, suspected as having, or at risk of developing that condition. In another example, the subject has been brought into a treatment situation entirely without the subject’s knowledge and / or intent. For example, a subject can obviously be in need of treatment but not be responsive to a previous surgery, and as described herein the present methods and retractors may save the subject’s life.

[0099] As discussed above, unless otherwise defined herein, scientific and technical terms used in connection with the present application shall have the meanings that are commonly understood by those of ordinary skill in the art to which this disclosure belongs. It should be understood that this invention is not limited to the particular methodology, protocols, devices, retractors, and reagents, etc., described herein and as such can vary. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which is defined solely by the claims. Definitions of common terms in immunology and molecular biology can be found in The Merck Manual of Diagnosis and Therapy;3The Encyclopedia of Molecular Cell Biology and Molecular Medicine;4Molecular Biology and Biotechnology: a Comprehensive Desk Reference;5Immunology;6Janeway's Immunobiology;7Lewin's Genes XI;8Molecular Cloning: A Laboratory Manual.;9Basic Methods in Molecular Biology;10Laboratory Methods in Enzymology;11Current Protocols in Molecular Biology (CPMB)12; Current Protocols in Protein Science (CPPS);13and Current Protocols in Immunology (CPI)14.

[0100] In the embodiments discussed and in any of the aspects, the disclosure described herein does not concern a process for cloning human beings, processes for modifying the germ line genetic identity of human beings, uses of human embryos for industrial or commercial purposes or processes for modifying the genetic identity of animals which are likely to cause them suffering without any substantial medical benefit to man or animal, and also animals resulting from such processes.

[0101] Other terms are defined herein within the description of the various aspects of the invention. It is clearly contemplated herein that the technology can be used in surgeries in addition to spinal surgeries, and the retractors and techniques disclosed herein are not limited by the accurate discussion of applications in spine surgeries.MODULAR MINIMALLY INVASIVE TUBULAR RETRACTOR

[0102] Traditional approaches to spinal surgery often involve open procedures that require large incisions to provide surgeons with adequate visibility and access to the surgical site.PCT ApplicationDocket No.: 408477-502001 WOThese open procedures can lead to significant muscle and tissue disruption, resulting in longer recovery times and increased postoperative pain for patients. To address these issues, minimally invasive spinal surgery techniques have been developed, utilizing tubular retractors to minimize tissue damage by providing a narrow pathway to the surgical site. However, these early tubular retractors were often rigid and fixed in length, limiting their adaptability to different patient anatomies and surgical requirements.

[0103] To solve these example problems, in an effort to improve the versatility of tubular retractors, some designs disclosed herein have incorporated removable shims or inserts that allow for the creation of access windows along the length of the retractor. These access windows enable surgeons to have better visibility and access to the surgical site without the need for larger incisions. Even with the advancements herein, the fixed length of these retractors still poses challenges, as they cannot be easily adjusted to accommodate varying surgical depths or patient anatomies during a procedure.

[0104] Further developments in tubular retractor technology disclosed herein have introduced adjustable distal end assemblies, which include telescoping or extendable segments, with threads, interlocking or snap segments. These designs allow the retractor to be lengthened or shortened, providing greater flexibility in reaching different surgical depths. However, these retractors often lack the ability to adjust the distal tip shape, which can be crucial for minimizing tissue trauma and improving the retractor's fit within the surgical site. Thus, the technology herein provides for adjustable and conformable tip shapes. The adjustment mechanisms are easily operable during surgery, expanding their practical utility in dynamic surgical environments.

[0105] In some embodiments, a tubular retractor for minimally invasive spinal surgeries includes a proximal end assembly with removable shims, allowing for the creation of access windows along the retractor's length. The retractor features an adjustable distal end assembly with telescoping or extendable segments, enabling the retractor to be lengthened or shortened to accommodate varying surgical depths. The distal tip is designed to have a beveled, contoured, or cylindrical shape for optimal contact with tissue surrounding the surgical site. The tubular retractor's length can be adjusted either during or prior to surgery, providing versatility and adaptability for different surgical requirements.

[0106] The devices and methods herein can be used for any surgery including spinal surgeries. There are many spinal procedures that make use of minimally invasive techniques. They can involve cutting away tissue (discectomy), fixing adjacent vertebrae to one another (spinal fusion), and replacing bone or other tissue. The main philosophy is less blood loss, tissue damage, and keep bone / tissue architecture. The name of the procedure often includes the region of the spine that is operated on, including cervical spine, thoracic spine, lumbar spine. These procedures, for example, can include: Anterior cervical discectomy, Artificial discPCT ApplicationDocket No.: 408477-502001 WO replacement or total disc replacement, Epidural lysis of adhesions, also known as percutaneous adhesiolysis or the Racz procedure, Laminectomy, Laminotomy, OLLIF Oblique lateral lumbar inter body fusion, Percutaneous vertebroplasty, a.k.a. Kyphoplasty, Endoscopic Discectomy, Percutaneous Stenoscopic Lumbar Decompression, Herniated discs, Spinal stenosis, Lumbar instability, Spinal tumors, Cervical nerve or disc procedures, Synovial cysts, Trauma, MIS PLIF (Minimally Invasive Posterior Lumbar Interbody Fusion), MIS TLIF (Minimally Invasive Transforaminal Lumbar Interbody Fusion), Pedicle Screws, Cervical Foraminotomy, Small or ultra-small endoscopic discectomy (called Nano Endoscopic Discectomy or Endoscopic Transforaminal Lumbar Discectomy and Reconfiguration). The devices herein can be made in varying sizes for macro to microsurgeries.

[0107] According to some aspects FIG. 1 illustrates a modular minimally invasive tubular retractor 110 that includes a main tube 120. The main tube can be reusable, while the first extension piece 125, second extension piece 130, third extension piece 135, fourth extension piece 140, and rotating beveled tip 145 are disposable. In some embodiments all pieces are disposable and / or reusable. In all embodiments, there can be additional extension pieces besides those shown. The rotating beveled tip 145 (or fourth extension piece) can provide any shape to adjust to a surgical site. The modular minimally invasive tubular retractor 110 can also have connection points for table mounts to fixate to the tube, like arms that can come off the tube to fixate to the tube arms that then fixate to the bed to create a stability feature, a rock-solid platform for the tube to stay in place. In FIG. 1 , the first mount arm 280 and the second mount arm 285 are optional and there can be one, two, three, (many) or zero mount arms. The modular minimally invasive tubular retractor 110 also can have channels and features to allow for light sources, sources of light, surgical light to shine inside the tube to illuminate the inside of the tube and the anatomy that the surgeon is looking at. The main tube collar 210 can have mounts for first removable shim 305, second removable shim 310, and additional removable shims (not shown). The first mount arm 280 and the second mount arm 285 can be affixed to the main tube collar 210 with first mount arm pin 287, second mount arm pin 288, third mount arm pin 289 and fourth mount arm pin 290 or any fastener known. More details are now discussed.

[0108] FIG. 2 provides an expanded view of a modular minimally invasive tubular retractor 110 illustrating that the entire extendable pieces can be telescoping or can include locking mechanisms or first threaded fitting 126, second threaded fitting 131 , third threaded fitting 136, fourth threaded fitting 141 , and additional threads or snap fasteners as needed for additional extension pieces.

[0109] Many retractors are flat on the distal end. FIG. 3 shows a rotating beveled tip 145 that can accommodate specific surgical sites. The lock fitting 150 can be, for example, a threaded fitting or a telescoping fitting. The fourth extension piece 140 and the rotating beveled tip 145PCT ApplicationDocket No.: 408477-502001 WO can be a single piece. FIG. 4A illustrates how the double bevel distal piece 155 can take different shapes than the rotating beveled tip 145 shown in FIG. 3. FIG. 4B shows the double bevel distal piece 155 on a wider view, illustrating that the double bevel distal piece 155 can fit on any of the retractors disclosed herein, for example, on a modular minimally invasive tubular retractor 110 or a 3-shim tubular retractor 111. FIG. 5 illustrates a double slant distal piece 160. FIG. 6 illustrates a cylindrical end distal piece 165. The distal end piece can be conformable; it can take any shape to advance surgeries.

[0110] FIG. 7 illustrates how the first removable shim 305 can be removed to provide a first surgical access window 170 and the second removable shim 310 can be removed to provide a second surgical access window 175. There can be only one removable shim, zero, or many (e.g., four or three) removable shims (not shown).

[0111] FIG. 8 shows a surgeon’s view of the main tube 120 with the mount arms removed and the removable shims removed to show the first surgical access window 170 and the second surgical access window 175.

[0112] FIG. 9A illustrates how stability can be provided by a first shim lock 315, a second shim lock 320, a third shim lock 335, and a fourth shim lock 340. These are configured to insert into the main tube collar 210 at the first shim receiver 325, second shim receiver 330, third shim receiver 345 and fourth shim receiver 350. The arrows in FIG. 9A illustrate how the first removable shim 305 and the second removable shim 310 can be removed independently as needed. The access gap 171 shows how a gap is made as the first removable shim 305 is slid proximally. Although not shown in FIG. 9A, the access gap 171 can become the first surgical access window 170 (in FIG. 7 or FIG. 8) or the second surgical access window 175 (FIG. 7 or FIG. 8). FIG. 9B illustrates how the retractors herein can include a third removable shim 355 with a fifth shim lock 360 and a sixth shim lock 365 and a fourth removable shim (not shown), a fifth removable shim (not shown) and additional removable shims are included in the scope of this disclosure. In some aspects, FIG. 9B illustrates a third removable shim 355 with a first mount arm 280. (The retractors may include any number of removable shims; mount arms are optional and may be provided in additional numbers). As well, in FIG. 9B there is only the one first mount arm 280 but any number of mount arms can be included. Thus, the 3-shim tubular retractor 1 1 1 can be considered any modification tubular retractor 1 1 1 as any distal piece, any number of arms, any length, any number of removable shims are contemplated to save lives and improve surgeries.

[0113] Typically retractor tube kits come in different lengths of separate retractors, making the kits cumbersome and expensive. If five different lengths are in the kit, it is five different tubes.PCT ApplicationDocket No.: 408477-502001 WOIf the window and the bevel on the end and the connection arm are not in an advantageous spot for the surgeon, then they have to change it (often on an emergency basis) either by moving the arm around or changing to the side that they are approaching.

[0114] The technology herein is modular in that you can build the tube to the length that is needed and position the bevel of the distal end of the tube to the direction needed and provide access.

[0115] The main tube collar 210 can have a plurality of multiple attachment arm points on the radius of the tube. The shims are designed at the top (FIG. 9) to interact with the main tube collar 210 so that these support the tube both in compression and also in expansion of the tube. So, when the shims are in place, the tube is as strong as a fully monolithic tube without the shims.

[0116] In some embodiments, the disclosure provides a tubular retractor system designed for minimally invasive spinal surgeries. The system may include a main tube with a collar at the proximal end and an extendable distal end. The main tube and collar can incorporate removable shims that, when removed, provide surgical access windows along the length of the main tube. The extendable distal end may consist of telescoping or extendable segments, allowing the retractor to be lengthened or shortened to accommodate varying surgical depths. The distal end of the retractor can be configured to have a beveled, contoured, or cylindrical shape, facilitating contact with the tissue surrounding the surgical site. This design may allow for adjustments in length either during or prior to surgery, enhancing the retractor's adaptability to different surgical scenarios.

[0117] The system can be used to perform minimally invasive spinal surgeries by providing access and maintaining contact with surrounding tissue, thereby facilitating surgical procedures. The tubular retractor may include removable shims, which can be removed to provide access windows along the length of the retractor. The removal of these shims may facilitate surgical access by creating windows that run from the collar along the main tube. The collar and main tube may comprise these removable shims, which, when removed, may provide surgical access windows. The access windows may be provided by the removal of one or more removable elements at any time, which may enhance the surgical procedure by allowing better access to the surgical site. The main tube and collar may form a proximal end assembly, which may provide structure and functionality to the retractor. The proximal end assembly may be integral to the retractor's design, ensuring that the retractor can be adjusted in length either during or prior to surgery.

[0118] The retractor may be configured to facilitate minimally invasive spinal surgeries by providing a tubular structure that can be adjusted for varying surgical depths. The retractor's design may allow for the removal of shims either during or prior to surgery, which may provide flexibility in surgical planning and execution. The retractor may be used in minimally invasivePCT ApplicationDocket No.: 408477-502001 WO spinal surgeries, where the access windows provided by the removal of shims may be significant for the procedure's success. The retractor's configuration may allow for the adjustment of its length, which may be necessary for accommodating different surgical depths and ensuring access to the surgical site.

[0119] In the context of the tubular retractor system, the adjustable distal end assembly may be configured to include telescoping or extendable segments. These segments may be designed to lengthen or shorten the tubular retractor, potentially allowing for adjustments in length either during or prior to a surgical procedure. This capability may facilitate the accommodation of varying surgical depths, thereby potentially enhancing the adaptability of the retractor for deeper or shallower surgeries. The extendable segments, which may form part of the adjustable distal end assembly, may be integral to this length adjustment process. The tubular retractor itself may be a key component in this system, potentially serving as the main structure to which the adjustable distal end assembly is attached. The extendable distal end may be configured to adjust the retractor's length, potentially providing a means to tailor the retractor's dimensions to the specific requirements of the surgical site. The telescoping segments may be another component of the adjustable distal end assembly, potentially offering an alternative mechanism for length adjustment. The overall system may be designed to ensure that the retractor can be adjusted in length, potentially providing flexibility and precision in minimally invasive spinal surgeries.

[0120] The distal tip of the tubular retractor may be configured to provide a beveled, contoured, or cylindrical shape for contacting tissue surrounding a surgical site. This configuration may allow the distal tip to contact the tissue with a specific shape, which may be beneficial for minimally invasive spinal surgeries. The distal end of the tubular retractor may be designed to minimize tissue damage during the procedure. The distal tip may be positioned at the far distal end of the adjustable distal end assembly, which may comprise one or more telescoping or extendable segments. These segments may be configured to lengthen or shorten the tubular retractor, allowing for adjustments in length either during or prior to surgery. This adjustability may accommodate varying surgical depths and may facilitate the retractor's use in deeper or shallower surgeries. The distal tip's shape may be important for ensuring proper contact with the tissue, potentially reducing the risk of tissue damage. The tubular retractor may be used in minimally invasive spinal surgeries, where the distal tip's configuration may play a role in the procedure's success. The retractor's design may provide the necessary structure and functionality to perform the surgery effectively, with the distal tip's shape being a component in achieving the desired surgical outcome.

[0121] According to an embodiment, the proximal end assembly of the tubular retractor may be formed by comprising a main tube and a collar at the proximal end of the main tube. This configuration may provide structure and functionality to the retractor, allowing it to bePCT ApplicationDocket No.: 408477-502001 WO effectively utilized in minimally invasive spinal surgeries. The collar and main tube may work in conjunction to form the proximal end assembly, which may be important for the overall operation of the tubular retractor. The extendable distal end may also be included in this configuration, potentially enhancing the retractor's adaptability to varying surgical depths. The main tube and collar may be integral components that contribute to the retractor's ability to provide surgical access windows when the removable shims are removed. This structural arrangement may facilitate the retractor's function in providing access to the surgical site while maintaining the necessary support and stability. The proximal end assembly, with its main tube and collar, may thus play a role in the retractor's operation, ensuring that it can be adjusted and utilized effectively during surgical procedures.

[0122] The mount arms may be configured to be mounted to a surgical table, which may facilitate the stabilization of the tubular retractor during minimally invasive spinal surgeries. The mounting may be important for ensuring that the retractor remains in a fixed position, thereby potentially enhancing the precision of the surgical procedure. The mount arms may be designed to interface with standard surgical tables, allowing for a secure attachment that can accommodate various surgical environments. This configuration may allow the surgical team to focus on the procedure without concern for the retractor's stability. The mount arms' ability to be affixed to the surgical table may also contribute to the overall functionality of the surgical system, providing a reliable support structure that may enhance the efficiency and effectiveness of the surgical process. According to an embodiment, a tubular retractor may be provided, comprising a proximal end assembly with removable shims, an adjustable distal end assembly, and a distal tip. The tubular retractor may be used in minimally invasive spinal surgeries. The proximal end assembly may include removable shims that, when removed, may provide access windows along the length of the tubular retractor. The adjustable distal end assembly may be configured to lengthen or shorten the tubular retractor, accommodating different surgical depths. The distal tip may be configured to provide a beveled, contoured, or cylindrical shape for contacting tissue surrounding a surgical site. The tubular retractor may facilitate minimally invasive spinal surgeries by allowing for adjustments in length either during or prior to a surgery.

[0123] The removable shims may be removed either during or prior to the surgery to provide the necessary access windows. The distal tip may contact the tissue with a specific shape, which may be selected based on the surgical requirements. The tubular retractor may be configured to perform minimally invasive spinal surgery by providing the necessary structural and functional components to facilitate the procedure.

[0124] FIG. 10 is a flowchart illustrating a method {e.g., steps 100-106) for providing a tubular retractor for minimally invasive spinal surgeries, according to an embodiment. At step 100, the tubular retractor may be provided, comprising a proximal end assembly with removable shims,PCT ApplicationDocket No.: 408477-502001 WO an adjustable distal end assembly, and a distal tip. The proximal end assembly may include a main tube and a collar, with the removable shims configured to be removed either during or prior to the surgery to provide access windows. The adjustable distal end assembly may comprise telescoping or extendable segments, allowing the tubular retractor to be lengthened or shortened to accommodate different surgical depths. The distal tip, located at the far distal end of the adjustable distal end assembly, may be configured to provide a beveled, contoured, or cylindrical shape for contacting tissue surrounding a surgical site. The tubular retractor may be used in minimally invasive spinal surgeries, facilitating access to the surgical site while minimizing tissue damage. The configuration of the tubular retractor may allow for adjustments in length either during or prior to the surgery, enhancing its versatility and adaptability to various surgical requirements.

[0125] In the context of step 102, the process may involve adjusting the length of the tubular retractor by either lengthening or shortening the adjustable distal end assembly. This adjustment can be achieved through the use of telescoping or extendable segments, which are integral to the adjustable distal end assembly. The purpose of this adjustment is to accommodate varying depths of the surgical site, thereby ensuring that the retractor can be effectively utilized in different surgical scenarios. The adjustable distal end assembly may comprise one or more telescoping segments or extendable segments, which are configured to facilitate this length adjustment. The adjustment of the tubular retractor's length may occur either during or prior to the surgery, providing flexibility in its application. This capability is important for adapting to the specific requirements of minimally invasive spinal surgeries, where precision and adaptability are paramount. The extendable segments, extendable distal end, and telescoping segments are key components that enable this functionality, allowing the retractor to be tailored to the surgical environment. The process of adjusting the retractor's length is a step in ensuring that the surgical site is accessible and that the retractor can be positioned optimally for the procedure. This step highlights the role of the adjustable distal end assembly in providing the necessary adaptability for successful surgical outcomes.

[0126] In the context of step 104, the process may involve the removal of removable shims from the proximal end assembly to create access windows along the length of the tubular retractor. This may be facilitated by the proximal end assembly, which may include a main tube and a collar at its proximal end, both of which may house the removable shims. The removal of these shims may occur either during or prior to the surgical procedure, allowing for flexibility in surgical planning and execution. The access windows, once created, may extend from the collar along the main tube, providing visibility and access to the surgical site. This configuration may be important for the effective use of the tubular retractor in minimally invasive spinal surgeries, as it may allow for precise and controlled access to the surgical area. The design of the proximal end assembly, with its removable shims, may be integral toPCT ApplicationDocket No.: 408477-502001 WO the functionality of the retractor, ensuring that the surgical team can adapt the instrument to the specific needs of the procedure. The potential for the shims to be removed at any point during the surgery may offer advantages in terms of adaptability and responsiveness to the dynamic conditions of the surgical environment.

[0127] In the context of step 106, the process may involve the interaction of the distal tip of the tubular retractor with the tissue surrounding a surgical site. The distal tip, which may be located at the far distal end of the adjustable distal end assembly, can be configured to have a beveled, contoured, or cylindrical shape. This configuration may allow the distal tip to contact the tissue surrounding the surgical site effectively. The distal tip's shape may be selected based on the specific requirements of the surgical procedure, potentially providing a suitable interface for minimizing tissue damage while maintaining access to the surgical site. The adjustable distal end assembly, which may include telescoping or extendable segments, can facilitate the positioning of the distal tip at the desired location. The distal tip's interaction with the tissue may be important for the retractor's function, as it may help in stabilizing the retractor and providing a clear pathway for surgical instruments. The choice of shape for the distal tip may be influenced by the need to accommodate different anatomical structures and surgical approaches, ensuring that the retractor can be adapted to various surgical scenarios.

[0128] FIG. 11 discusses the removable shims in the context of a system, which (the shims) may be integral to the tubular retractor system for minimally invasive spinal surgeries. The removable shims may be designed to provide surgical access windows when removed, either during or prior to a surgical procedure. These shims may be part of the proximal end assembly, which may include a main tube and a collar. The removal of these shims may allow for the creation of access windows that run along the length of the tubular retractor, facilitating the surgical process by providing access to the surgical site. The adjustable segments of the component 204 may be integral to the functionality of the tubular retractor system.

[0129] These segments may be configured to adjust the length of the retractor, which may be necessary for accommodating varying surgical depths. The adjustable segments may include telescoping or extendable segments, which may allow the retractor to be lengthened or shortened as needed. This adjustability may be achieved either during or prior to a surgical procedure, providing flexibility in surgical planning and execution. The adjustable segments may correlate with the adjustable distal end assembly, which may be designed to facilitate the length adjustment of the tubular retractor. This capability may be important for ensuring that the retractor can be tailored to the specific requirements of each surgical case, potentially enhancing the precision and effectiveness of minimally invasive spinal surgeries. The extendable segments may be configured to lengthen and / or shorten the tubular retractor, which may be necessary for deeper or shallower surgeries. This configuration may be aligned with the purpose of adjusting the retractor for surgical depth. The adjustable segments mayPCT ApplicationDocket No.: 408477-502001 WO work in conjunction with other components, such as the distal tip, to ensure that the retractor can be positioned accurately and securely within the surgical site. The distal tip may be configured to provide a beveled, contoured, or cylindrical shape, which may be important for contacting the tissue surrounding the surgical site.

[0130] This configuration may minimize tissue damage and enhance the overall safety and efficacy of the surgical procedure. The adjustable segments may also be associated with the extendable distal end, which may provide additional functionality and versatility to the tubular retractor system. The extendable distal end may be configured to adjust the length of the retractor, which may be important for accommodating different surgical depths and ensuring access to the surgical site. The adjustable segments may be a component of the tubular retractor system, providing the necessary adjustability and flexibility to facilitate minimally invasive spinal surgeries. The distal tip, identified as component 206, may be configured to contact tissue with specific shapes, such as beveled, contoured, or cylindrical. This configuration may allow the distal tip to effectively engage with the tissue surrounding a surgical site. The distal tip may be part of the tubular retractor system, which is designed for minimally invasive spinal surgeries. The distal tip may be located at the far distal end of the adjustable distal end assembly, which may include telescoping or extendable segments.

[0131] These segments may be configured to lengthen or shorten the tubular retractor, thereby accommodating different surgical depths. The distal tip's shape may be important for minimizing tissue damage during surgery, as it may provide a suitable contact surface with the surrounding tissue. The distal tip's configuration may be integral to the overall functionality of the tubular retractor, as it may ensure precise and safe contact with the surgical site. The distal tip may work in conjunction with other components, such as the removable shims and adjustable segments, to facilitate the surgical procedure. The removable shims may provide access windows along the length of the tubular retractor, while the adjustable segments may allow for length adjustments during or prior to surgery. The distal tip's design may be important for the retractor's adaptability and effectiveness in various surgical scenarios.

[0132] In some examples, a sliding access tubular retractor for performing minimally invasive surgery includes a hollow windowed insertion tube with proximal and distal ends. The tube features first and second slotted windows on opposite sides, each with a sliding panel to open or close the windows. The distal end is interchangeable and custom-shaped to fit targeted surgical sites. The method for using the retractor involves inserting it into tissue, sliding the panels to close the windows during insertion, and retracting the panels to open the windows for surgical access during the actual surgery. The distal end can be fitted with custom shapes to suit the surgical site.

[0133] The technology disclosed herein begins with a sliding access tubular retractor {e.g., a tubular retractor with sliding doors). In some embodiments, the technology features a slidingPCT ApplicationDocket No.: 408477-502001 WO access tubular retractor for performing a minimally invasive surgery; the tubular retractor comprising a hollow windowed insertion tube capable of accepting a surgical instrument in the hollow portion of the tube and including a proximal end with a mount bracket and a custom shaped distal end; the retractor including a first slotted window on one side of the tube and a second slotted window on the opposite side of the tube (there can be one or more slotted windows and first and second are non-limiting examples); wherein the first slotted window includes a first sliding panel, and the second slotted window includes a second sliding panel; wherein the tubular retractor is operative to be inserted into a tissue of a subject, distal end first, with both sliding panels fully slid down along a length of the tube, and after the insertion into the tissue, either of the sliding panels can be retracted upwards to the proximal end either partially or fully to be removed from the tubular retractor, to open either the first slotted window and / or the second slotted window to provide access to a targeted surgical site at the distal end; wherein the partial or full removal of the first sliding panel and / or the second sliding panel provides one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end; and wherein the custom shape distal end can be interchangeably fitted with pre-designed shapes to fit with the targeted surgical site.

[0134] In accordance with embodiments, a sliding access tubular retractor for performing minimally invasive surgery is provided. The retractor comprises a hollow windowed insertion tube capable of accepting a surgical instrument, with a proximal end and a distal end. The hollow windowed insertion tube includes a first slotted window on one side and a second slotted window on the opposite side. A first sliding panel is configured to slide along the length of the hollow windowed insertion tube to open or close the first slotted window, and a second sliding panel is configured to slide along the length of the hollow windowed insertion tube to open or close the second slotted window.

[0135] Additionally, the retractor includes an interchangeable custom-shaped distal end configured to fit a targeted surgical site. In another embodiment, the proximal end of the retractor includes a mount bracket. In yet another embodiment, the first and second sliding panels are configured to be retracted upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube. Another embodiment provides that the first and second sliding panels are configured to provide one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end. In a further embodiment, the interchangeable custom-shaped distal end is configured to be fitted with pre-designed shapes to fit the targeted surgical site. Another embodiment specifies that the hollow windowed insertion tube is capable of accepting the surgical instrument in a hollow portion of the tube.

[0136] In accordance with other embodiments, a method for performing minimally invasive surgery using the sliding access tubular retractor is provided. The method comprises insertingPCT ApplicationDocket No.: 408477-502001 WO the retractor into the tissue of a subject, wherein the retractor includes a hollow windowed insertion tube with a proximal end, a distal end, a first slotted window on one side, a second slotted window on the opposite side, a first sliding panel, and a second sliding panel. The method further includes sliding the first and second sliding panels along the length of the tube to close the first and second slotted windows during insertion, and retracting at least one of the sliding panels along the length of the tube to open at least one of the slotted windows, thereby providing access to a targeted surgical site at the distal end.

[0137] The surgeon can access either side of the retractor by using either one of the sliding panels. The method also includes interchangeably fitting the distal end with a custom-shaped distal end to fit the targeted surgical site. In another embodiment, retracting at least one of the sliding panels comprises retracting the panel upwards to the proximal end either partially or fully to be removed from the tube. Another embodiment provides that retracting at least one of the sliding panels provides one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end.

[0138] In a further embodiment, interchangeably fitting the distal end with the custom-shaped distal end comprises fitting the distal end with pre-designed shapes to fit the targeted surgical site. Another embodiment includes accepting a surgical instrument in a hollow portion of the tube. In yet another embodiment, inserting the retractor into the tissue of the subject comprises inserting the distal end first into the tissue. Another embodiment specifies that the proximal end includes a mount bracket. In accordance with other embodiments, the first and second sliding panels are configured to slide independently of each other.

[0139] Another embodiment provides that the first and second slotted windows extend along a substantial portion of the length of the tube. In a further embodiment, sliding the first and second sliding panels comprises sliding the panels independently of each other. Another embodiment specifies that the first and second slotted windows extend along a substantial portion of the length of the tube. In yet another embodiment, the interchangeable customshaped distal end is configured to be removably attached to the distal end of the tube. Another embodiment provides that interchangeably fitting the distal end with the custom-shaped distal end comprises removably attaching the custom-shaped distal end to the distal end of the tube. In a further embodiment, the first and second sliding panels are configured to be retracted in a proximal direction to open the first and second slotted windows, respectively.

[0140] A huge problem with prior art tubular retractors (FIG. 12A, FIG. 12B) is that the central hollow tube (516 or insertion tube 515) can only accept surgical instruments down the narrow barrel of the tube, so the surgeon has a very small working space at the targeted surgical site. The surgery can be compared to working through a small pipe. If the tubular retractor is long, e.g., 6 cm in FIG. 12A, the surgeon’s access at the targeted surgical site is very limited. ThePCT ApplicationDocket No.: 408477-502001 WO technology disclosed in FIG. 13A and FIG. 13B solves this huge problem, providing a wealth of surgical access to the surgeon.

[0141] Another huge problem, for example, is that the distal end 518 or distal opening 517 of the prior art tubular retractors (FIG. 12A, FIG. 12B) is hard and shaped like a cylinder’s end. This distal end does not mate well with most target surgical sites. The present technology provides at least one custom distal end 617 (FIG. 13A) that can be interchanged to fit (or mate) with various targeted surgical sites. Thus, the technology herein saves lives, solves long-felt but unmet needs, and provides surgeons / patients a better surgery and outcome.

[0142] According to some aspects, the sliding access tubular retractor herein features slotted windows with sliding panels that can be partially or fully retracted to provide adjustable access to the surgical site. The custom-shaped distal end can be interchangeably fitted with predesigned shapes and / or with custom hardness.

[0143] FIG. 12A shows a tubular retractor 500 for use in a spinal surgery (prior art). The insertion tube 515 has a proximal opening 520 that extends through the tube and has a distal opening 517 that is circular. The offset bracket 510 has a mount bracket 505.

[0144] FIG. 12B shows the tubular retractor 500 inserted into soft tissue 535 so that the distal opening 517 contacts a target tissue 540 for the surgery. The insertion tube 515 keeps the soft tissue 535 open so that a first surgical tool 530 can be inserted through proximal opening 520 to perform work on the target tissue 540 at the distal opening 517. The mount bracket 505 is affixed to a holding bracket 525.

[0145] FIG. 13A shows a sliding access tubular retractor 600 including a windowed insertion tube 615 with a first sliding window 625 and a second sliding window 630 (in back). Each sliding window includes a first sliding slot 635 and a second sliding slot 640. The first sliding window 625 accepts a first sliding panel 645 into it as the first sliding panel 645 is pushed downward. The first sliding panel 645 includes a first extension 655 and a second extension 660. The first extension 655 inserts into the second sliding slot 640 and the second extension 660 inserts into the first sliding slot 635. Although not visible in the back, the second sliding window 630 also includes a first sliding slot and a second sliding slot.

[0146] The second sliding panel 650 includes a first sliding extension 665 and a second sliding extension 670, each of which will slide into the first sliding slot and the second sliding slot. The first sliding panel 645 and the second sliding panel 650 each include a lock 680 and a locking mechanism 685 such that each of the first sliding panel 645 and the second sliding panel 650 can be locked into the windowed insertion tube 615 when pushed down if desired. On one side of the sliding access tubular retractor 600 is a first mount bracket 605 with a first offset bracket 610, and on another side is a second mount bracket 606 with a second offset bracket 611. The windowed proximal opening 620 extends through the windowed insertion tube 615 and ends in a custom distal end 617 (at least one) that has interchangeable shaped ends.PCT ApplicationDocket No.: 408477-502001 WO

[0147] FIG. 13B illustrates how a first side tool 300 and a second side tool 400 can be inserted through the first sliding window 625 and the second sliding window 630 to allow side access to a target surgical area. The windowed proximal opening 620 can be used for tool access. The first mount bracket 605 and second mount bracket 606 and the first offset bracket 610 and second offset bracket 611 are all shown for use with various tools and / or surgeries.

[0148] In some embodiments, the layout depicts the collar 210 at the proximal end of the tube with multiple circumferential attachment bosses indexed at clocking positions (e.g., 0°, 30°, 60°, 90°, 120°, 150°, 180°). At each position, a mount bracket 605 or 606 can be secured to the collar via a keyed interface that prevents rotation once locked. Between the collar and each mount arm, offset brackets 610 and 611 provide radial and axial stand-off, allowing the arm to clear patient anatomy and drapes while aligning with the surgeon’s preferred approach angle. Each offset bracket carries engraved angular indicia (e.g., ±0-45°) and a detent or cam that provides tactile indexing as the bracket pivots.

[0149] From the offsets, the first mount arm 280 and second mount arm 285 extend to the table clamp. Each arm includes a telescoping segment with a length scale and a quick-lock lever; the scale indicates incremental extension (for example, 5 mm steps) so the arm can be returned to a verified setting. A proximal ball-and-socket or universal joint near the collar allows fine angular adjustment, while a distal pivot near the table clamp facilitates gross positioning. The figure would show reach envelopes for 280 and 285 at several clocking positions, illustrating clearance from cables and accessories. Suggested callouts include arrows indicating rotation about the collar axis, arcs showing bracket pivot ranges at 610 / 611 , and linear rulers along the arms to denote extension. Together, the 605 / 606 bracket placements, 610 / 611 offsets, and adjustable arms 280 / 285 provide stable fixation with repeatable angular and length settings, enabling ergonomic tube orientation without compromising the working corridor.

[0150] According to some aspects FIG. 14 illustrates a modular minimally invasive tubular retractor 110 with a main tube 120. The main tube can be reusable, while the first extension piece 125, second extension piece 130, third extension piece 135, fourth extension piece 140, and rotating beveled tip 145 (all optionally added) can be disposable. In some embodiments all pieces are disposable and / or reusable. In all embodiments, there can be additional extension pieces besides those shown. The rotating beveled tip 145 (or fourth extension piece) can provide any shape and / or rotation to adjust to a surgical site. The modular minimally invasive tubular retractor 110 can also have connection points for table mounts to fixate to the tube, like arms that can come off the tube to fixate to the tube arms that then fixate to the bed to create a stability feature, a rock-solid platform for the tube to stay put. In FIG. 14, the first mount arm 280 and the second mount arm 285 are optional and there can be one, two, three, (many) or zero mount arms. The modular minimally invasive tubular retractor 110 also canPCT ApplicationDocket No.: 408477-502001 WO have channels and features to allow for light sources, sources of light, surgical light to shine inside the tube to illuminate the tube interior and target anatomy {e.g., inside of the tube and the anatomy that the surgeon is looking at). The optional first dilator (non-cannulated) 405, working tip of first dilator 406, second dilator (cannulated) 410 and third dilator (cannulated) 415 are shown. There are at least 3 optional dilators that can be used with any of the embodiments disclosed herein. The first one is non-cannulated 405 and can be hooked up to navigation and / or neuromonitoring. The 2nd and 3rd dilators are cannulated to sequentially dilate up to the tube inner diameter

[0151] In summary, according to some aspects, FIG. 14 shows a modular minimally invasive tubular retractor 110 with the main tube 120 and optional extension pieces 125, 130, 135, 140 terminating at a rotating bevel tip 145. A mount arm 280 and shim features 305 are shown at the collar for table fixation and stability. Three dilators are depicted along a common axis: a first dilator (non-cannulated) 405, a second dilator (cannulated) 410, and a third dilator (cannulated) 415. In use, the non-cannulated 405 establishes a safe initial tract under navigation and / or neuromonitoring. The cannulated 410 and 415 then sequentially expand the tract to the inner diameter of the tube, allowing atraumatic insertion while maintaining trajectory to the targeted anatomy. The rotating bevel tip 145 at the distal end can be oriented to match local anatomy; later figures show keyed features that let a dilator actively rotate the bevel to a desired orientation. FIG. 14 summarizes the stacked relationship of the retractor and the dilators and illustrates how the kit supports both controlled dilation and adjustable distal geometry without exchanging to separate retractors during the approach.

[0152] FIG. 15 illustrates a modular minimally invasive tubular retractor 110 with a main tube 120. The first dilator (non-cannulated) has been pulled out of the second dilator 410 and is shown at bottom. Thus, according to some embodiments, FIG. 15 illustrates the first dilator (non-cannulated) 405 withdrawn from within the second dilator 410. The standalone 405 is shown with an attachment / traction handle 407 and a tapered working tip 406 suited for initial passage through soft tissue along the planned path. In this stage, the retractor 110 with tube 120 and distal assembly 145 remains in place, while the cannulated 410 / 415 stay co-axially aligned at the entry to preserve the tract. The first dilator’s role is to confirm a safe trajectory, permit neuromonitoring or navigation hookups, and create a gentle pilot channel that accepts the larger, cannulated expanders. As the 405 is removed, the surgeon can inspect the tract and confirm stability before advancing the cannulated 410 over the same path. The depiction underscores the modular workflow: the system keeps the working corridor aligned with the retractor, minimizing exchanges and reducing the risk of losing the trajectory while transitioning from scouting to controlled dilation.

[0153] In FIG. 16, the second dilator 410 has been pulled out of the third dilator 415 showing a working handle 412 and a working tip 414. In FIG. 16, the third dilator (cannulated) 415 hasPCT ApplicationDocket No.: 408477-502001 WO been pulled from main tube 120 to show the working handle of the third dilator 417 and the working tip of third dilator 419. In some embodiments, FIG. 16 shows the second dilator (cannulated) 410 removed from within the third dilator 415, exposing the second dilator’s working handle 412 and working tip 414. The retractor 110 and tube 120 remain positioned with the rotating bevel tip 145. In the sequence, 410 expands the pilot channel created by 405; once adequate diameter and tissue accommodation are achieved, 410 is withdrawn to hand off to the final cannulated expander 415. The figure transitions the discussion to orientation control: later views (FIGs. 18A-18B) depict a subtle bump / notch feature at the inner wall of the rotating bevel and a longitudinal keyway on the final dilator. Those keyed elements allow a positive, rotational coupling — so the surgeon can impart rotation to the bevel via the dilator when precise angular positioning is needed. FIG. 16 therefore captures both the dilation step-down (405— >410— >415) and the prelude to bevel orientation, emphasizing that the workflow preserves access while progressively enlarging the corridor and preparing for final alignment at the target site.

[0154] FIG. 17 introduces more details of a final cannulated dilator and rotation of the bevel tip under fluoroscopic and visual guidance. FIG. 17 depicts the third dilator (cannulated) 415 with its working handle 417 and working tip 419 as the last expander in the series; the earlier dilators 405 and 410 are shown withdrawn. The final dilator includes a longitudinal notch that mates with a small internal bump / notch at the rotating bevel tip 145 (see FIGs. 18A-18B), creating a keyed engagement. With this coupling, rotating the dilator rotates the distal bevel so the lip can be aimed to retract or shield tissue optimally at the target. Fluoroscopic confirmation is facilitated by a blind-hole 430 in the bevel that accepts a metal pin 435, which shows orientation under imaging; concurrently, a top slot 450 at the tube can house a camera 455 and / or light 460 for direct visualization. After the corridor is fully dilated and the bevel is oriented, the dilator 415 can be removed, leaving the retractor 110 in its final, patient-specific configuration with a stable, illuminated working channel and anatomically aligned distal bevel for instrument passage and treatment.

[0155] FIG. 18A provides an enlarged view of the rotating bevel tip 145 at the distal end of the tubular retractor 110. An internal bump 425 is formed on the inside of the bevel, and the third (cannulated) dilator 415 includes a longitudinal notch 426 sized to mate with the bump. When the notch 426 is seated over the bump 425, the dilator and bevel are rotationally coupled; twisting the dilator therefore rotates the bevel to aim its lip relative to target tissue. A blind-hole 430 or a through-hole 430 is positioned on the bevel to accept an orientation pin 435 for fluoroscopic confirmation when needed. The figure shows the coaxial relationship among the tube 120, the dilator 415, and the bevel 145, and illustrates how the surgeon can both preserve the access corridor and achieve fine rotational alignment without exchanging instruments or relying on external levers near the incision.PCT ApplicationDocket No.: 408477-502001 WO

[0156] FIG. 18B complements FIG. 18A by depicting the keyed elements during engagement and disengagement. The dilator’s longitudinal notch 426 approaches the internal bump 425 as the dilator 415 advances, creating a guided ramp-in that provides tactile feedback. Once seated, small angular adjustments imparted to the dilator are transmitted to the bevel 145, while axial withdrawal cleanly disengages the coupling. The orientation pin 435 can be placed into blind hole 430 (or through hole 430) when imaging feedback is desired; removal of the pin allows free rotation again. The view emphasizes surgeon ergonomics: rotation is effected with the same in-line hand position already used for dilation, minimizing torque on the incision. The depiction also clarifies that the coupling lies inside the protected distal envelope, away from skin and drapes, reducing risk of snagging external instrumentation.

[0157] FIG. 19 highlights the accessory slot 450 at the proximal region of the tubular retractor 110, configured to accept powered or passive adjuncts that enhance visualization, hemostasis, and ergonomics. In one mode, a camera 455 and / or light 460 are housed within the slot to deliver direct visualization and illumination aligned with the working corridor. Beyond these, the slot 450 can accept additional accessories sized to the slot profile and retained by a spring detent or bayonet catch: a low-profile suction cannula for smoke and fluid evacuation; a combined irrigation / suction tip to clear the field; a smoke-evacuation tube integrated with a charcoal filter; a navigation probe or EMG lead for trajectory confirmation; an endoscopic imaging fiber to supplement the camera; a monopolar / bipolar cautery pencil holder that maintains standoff from tissue; a micro-ultrasound or Doppler probe for vessel mapping; and a cable-management clip to route lines along the tube 120 and mount arm 280. The slot allows fore-aft positioning so accessories can be aimed without occluding the operative aperture. Accessories can be swapped without disturbing retractor orientation or the distal bevel 145; when used with the keyed dilator coupling (FIGs. 18A-18B), the surgeon can orient, visualize, irrigate, and treat through a single stable corridor, reducing exchanges and shortening setup time..

[0158] According to some aspects, a longitudinal accessory slot 450 is formed at or near the proximal region of the tubular retractor and is oriented parallel to the retractor axis. The slot accepts swappable modules that include, without limitation: a camera 455, a light 460, a combined camera-light unit, suction, irrigation or smoke-evacuation tips, a navigation / EMG probe, an endoscopic imaging fiber, a cautery-instrument holder, a micro-ultrasound or Doppler probe, and a cable-management clip. Each module includes a standardized tongue or rail profile that mates with a complementary groove of the slot 450. A retention mechanism — e.g., spring detent, bayonet catch, or threaded clamp — secures the module; release is achieved by depressing a latch or rotating a quarter-turn handle. The modules can be positioned fore-aft within a defined travel range to optimize line-of-sight and workingPCT ApplicationDocket No.: 408477-502001 WO clearance without occluding the operative aperture. Electrical / optical leads route proximally along the slot profile and may be captured by the cable clip to keep the field organized. The slot geometry is configured so that accessories remain coaxial with, or deliberately offset from, the central lumen as indicated by the module design, thereby preserving the working corridor while enabling simultaneous visualization, illumination, evacuation, or sensing functions.

[0159] In some embodiments, a windowed insertion tube 615 defines first and second slotted windows 625 and 630 bounded by sliding slots 635 and 640. First and second sliding panels 645 and 650 carry respective extensions 655 and 660 that translate within the slots to modulate side access; in some uses one panel is removed entirely to maximize lateral clearance. The tube 615 couples distally to an adjustable distal assembly whose overall length can be set intraoperatively; a custom distal end 617 supports a rotatable beveled tip 145. Rotation is imparted by a keyed dilator whose longitudinal notch 426 engages an internal bump 425 within the tip, permitting surgeon-controlled orientation while the panels define asymmetric or symmetric access windows. Sliding extensions 665 and 670 may be used to guide or limit panel travel. The combined embodiment therefore provides simultaneous benefits: adjustable insertion depth, controlled bevel orientation at the target, and selective side windows for triangulated instrument paths — all within one stable corridor. The textual disclosure enables any skilled person to implement these combinations without undue experimentation.

[0160] In some embodiments, the techniques described herein relate to a sliding access tubular retractor for performing minimally invasive surgery, including: a tubular retractor assembly including a hollow windowed insertion tube for accepting a surgical instrument, the tubular retractor assembly configured to provide access to a targeted surgical site and allow placement of the surgical instrument; sliding window panels disposed on the tubular retractor assembly, the sliding window panels configured to be inserted into tissue, retracted upwards, and removed to position the tubular retractor assembly, open access windows, and provide access to the targeted surgical site; and angled instrument ports formed by the sliding window panels, the angled instrument ports configured to place surgical instruments at an angle to access the targeted surgical site.

[0161] FIG. 20 illustrates the tubular retractor 120 deployed on vertebral bone 850 with the surgical corridor centered on target tissue 855. The figure emphasizes the instrument working envelope 800, depicting first and second side tools 300 and 400 introduced at oblique angles spanning about 0-60° relative to the retractor axis. A mount arm 285 stabilizes the retractor to maintain orientation while angled instruments are advanced. In concert with the disclosures of the earlier figures, the arrangement enables triangulation without repositioning the tube: the surgeon may orient the distal bevel (see FIGs. 18A-18B) and select partial or full side access via windows / panels (see, e.g., FIGs. 7-9 and FIGs. 13A-13B) so that angled tools reach thePCT ApplicationDocket No.: 408477-502001 WO target while adjacent tissue remains protected. Visualization and field control may be maintained from the proximal slot (see FIG. 19) using a camera and / or light, optionally accompanied by suction or irrigation to keep the view clear during angulated work. The obliquity range indicated by 800 supports ipsilateral and contralateral tasks — such as decompression, discectomy, or implant preparation — while the distal footprint remains seated on bone 850. In summary, FIG. 20 demonstrates that the system preserves a stable central corridor yet provides generous angular freedom for instrument trajectories to address the target tissue 855 effectively.

[0162] In some embodiments, the rotatable distal bevel 145 is a hollow tip configured to couple to the distal end assembly; an internal bump 425 projects from the inner surface. A cannulated dilator includes a longitudinal notch 426 sized to seat over the bump 425 so that rotation of the dilator transmits torque to the bevel for angular positioning. A blind-hole 430 or a through-hole 430 in the bevel receives an orientation pin 435 to provide fluoroscopic confirmation of the bevel’s azimuth; withdrawal of the pin restores free rotation. The bevel may be interchanged with contour or cylindrical tips using a reversible coupling (e.g., bayonet or threaded interface) that provides tactile locking. In manufacture, the bump 425 is formed as an integral boss or insert, and the notch 426 is dimensioned to provide positive engagement with low friction. Clearances are selected to allow repeated engagement and disengagement while preserving a fluid-smooth inner lumen for atraumatic instrument passage.

[0163] In a non-limiting example, FIG. 21 presents an exploded distal-end assembly showing, from proximal to distal, collar / thread modules (e.g., 125, 130, 135), a rotatable beveled tip body 145, and the working interface with the cannulated dilator 415. The beveled tip includes an internal bump 425 and a blind-hole 430 sized for an orientation pin 435. The dilator 415 carries a longitudinal notch 426 and a distal working end 419. In combination, the notch 426 couples to the bump 425 so rotation of the dilator transmits torque to the tip body 145; the optional pin 435 provides fluoroscopic confirmation of angular orientation via the blind-hole 430.

[0164] In a prophetic description of FIG. 21 , the distal tip 145 is configured as a thin-wall, rotatable hood that mates with the adjustable distal assembly via the threaded collar elements 125 / 130 / 135. On its inner surface, a low-profile internal bump 425 is formed as an integral boss (or a pressed / laser-brazed insert) with rounded edges to avoid gouging. The cannulated third dilator 415 features a longitudinal notch 426 that extends proximally from the working end 419. The notch includes a lead-in chamfer so that, as the dilator advances inside the tip 145, the chamfer engages the bump 425 and guides the two into concentric, rotational contact. That “ramp-in” geometry provides tactile feedback: the surgeon feels a gentle rise as thePCT ApplicationDocket No.: 408477-502001 WO chamfer climbs the bump, followed by a seated detent when the flat of the notch drops over the crest of the bump.

[0165] In some embodiments, with the notch 426 fully seated, torque applied to the dilator 415 is transmitted directly to the beveled tip 145, allowing fine angular positioning of the bevel lip relative to nearby tissue. Because the contact lies on the internal surface and because the notch edges are radiused, rotation occurs without sharp catches or particulate generation. Diametral clearance between 425 and 426 is selected to balance smooth sliding with positive drive (representatively on the order of a few hundredths of a millimeter), and the mating surfaces may be polished or coated with a biocompatible, low-friction finish to minimize stiction after sterilization.

[0166] According to some aspects, the blind-hole 430 and removable pin 435 provide an optional orientation indicator. When the pin is placed, its radiopaque signature allows quick verification of the bevel’s azimuth under fluoroscopy; the pin is then withdrawn to restore free rotation and to clear the lumen for instruments. In variants, one or more radiopaque bands can supplement or substitute for the pin, but the keyed notch-and-bump coupling remains the primary driver of controlled orientation.

[0167] Importantly, the notch 426 allows in-and-out motion of the dilator without losing the coupling: axial translation is free while rotational engagement persists whenever the notch overlays the bump. Thus, the surgeon can probe, irrigate, or exchange instruments through 415 while still using gentle twists to nudge the bevel to a new angle. If fully disengaged rotation is desired, the dilator is retracted a short distance and rotated so the notch bypasses the bump; the bevel then free-floats.

[0168] Example (non-limiting) materials may include stainless steel or titanium for the tip body 145 and stainless steel or PEEK for the dilator 415, with edges radiused (e.g., -0.2-0.5 mm) to preserve atraumatic flow through the lumen. The internal geometry avoids external protrusions, keeping the coupling safely within the protected distal envelope. Taken together, FIG. 21 enables both precise rotational control and smooth longitudinal motion using simple, manufacturable features that integrate cleanly with the distal thread / collar stack and with the broader system workflow.

[0169] Industrial applicability: The devices, systems, and methods disclosed herein are susceptible of industrial application. Components can be manufactured using conventional machining, molding, or additive processes and supplied as sterile, single-use or reprocessable kits for routine use in hospitals and ambulatory surgical centers.

[0170] Global “mix-and-match” / combinability: Except where expressly technically incompatible, features described for one embodiment (e.g., removable shims / windows, adjustable distal segments, keyed bevel orientation, accessory slot modules, and mount armPCT ApplicationDocket No.: 408477-502001 WO placements) are disclosed in combination with features of any other embodiment. Labels such as “first / second” are solely for distinction and do not require order or number.

[0171] Sterilization & reprocessing options: In reusable embodiments, materials and finishes are selected to withstand steam, low-temperature gas plasma, or gamma sterilization. Representative reprocessing includes ultrasonic cleaning, neutral-pH detergents, and visual / functional checks of locks and rails; recommended reuse cycles are established per material selection and hospital SOPs.

[0172] Surface finishes & coatings (atraumatic / low-friction): Patient-contacting surfaces may be electropolished (Ra < 0.8 pm) or coated with a biocompatible lubricious layer (e.g., hydrophilic or PTFE-like) to reduce insertion force. Exterior grasping areas can be microtextured or knurled to improve wet grip without harboring bioburden. Any surface can be nanotextured for anti-microbial effects.

[0173] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, further including an interchangeable distal tip configured to fit with the targeted surgical site to match anatomy of the surgical site for optimal positioning, wherein the interchangeable distal tip includes anatomical fitting shapes.

[0174] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the tubular retractor assembly includes a proximal end with a mount bracket and a custom shaped distal end.

[0175] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the sliding window panels include a first sliding panel disposed in a first slotted window on one side of the tubular retractor assembly and a second sliding panel disposed in a second slotted window on an opposite side of the tubular retractor assembly.

[0176] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to be retracted upwards to the proximal end either partially or fully to be removed from the tubular retractor assembly.

[0177] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to open at least one of the first slotted window or the second slotted window to provide access to the targeted surgical site at the distal end.

[0178] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the angled instrument ports are configured to provide angled access to the targeted surgical site relative to a main axis of the tubular retractor assembly.

[0179] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the sliding window panels are configured to be inserted into thePCT ApplicationDocket No.: 408477-502001 WO tissue with the tubular retractor assembly, the distal end of the tubular retractor assembly being inserted first with the sliding window panels fully slid down along a length of the tubular retractor assembly.

[0180] In some embodiments, the techniques described herein relate to a method of accessing a surgical site, including: inserting a tubular retractor assembly into tissue, the tubular retractor assembly including sliding window panels fully slid down along a length of the tubular retractor assembly; retracting at least one of the sliding window panels upwards to open an access window in the tubular retractor assembly; placing a surgical instrument through the tubular retractor assembly and the access window to access a targeted surgical site; placing at least one surgical instrument through an angled instrument port formed by the at least one of the sliding window panels to access the targeted surgical site at an angle relative to the tubular retractor assembly; and wherein a surgeon performing a surgery can access either side of the tubular retractor via using a sliding window panel on one side of the retractor and / or on the other side of the retractor.

[0181] According to some aspects, the techniques described herein relate to a method, further including removing the at least one of the sliding window panels from the tubular retractor assembly to provide increased access to the targeted surgical site.

[0182] In some embodiments, the techniques described herein relate to a method, wherein retracting the at least one of the sliding window panels includes retracting the at least one of the sliding window panels to a proximal end of the tubular retractor assembly.

[0183] According to some aspects, the techniques described herein relate to a method, wherein retracting the at least one of the sliding window panels includes partially retracting the at least one of the sliding window panels.

[0184] In some embodiments, the techniques described herein relate to a method, wherein the sliding window panels include a first sliding panel in a first slotted window on one side of the tubular retractor assembly and a second sliding panel in a second slotted window on an opposite side of the tubular retractor assembly.

[0185] According to some aspects, the techniques described herein relate to a method, wherein retracting the at least one of the sliding window panels includes retracting at least one of the first sliding panel or the second sliding panel.

[0186] In some embodiments, the techniques described herein relate to a method, further including fitting an interchangeable distal tip to the tubular retractor assembly to match anatomy of the targeted surgical site for optimal positioning.

[0187] According to some aspects, the techniques described herein relate to a method, wherein the interchangeable distal tip includes pre-designed anatomical fitting shapes.

[0188] In some embodiments, the techniques described herein relate to a method, wherein placing the at least one surgical instrument through the angled instrument port includesPCT ApplicationDocket No.: 408477-502001 WO accessing the targeted surgical site at the angle relative to a main axis of the tubular retractor assembly.

[0189] According to some aspects, the techniques described herein relate to a method, wherein inserting the tubular retractor assembly includes inserting the tubular retractor assembly distal end first into the tissue.

[0190] In some embodiments, the techniques described herein relate to a method, wherein the tubular retractor assembly includes a hollow windowed insertion tube for accepting the surgical instrument.

[0191] According to some aspects, the techniques described herein relate to a method, wherein the tubular retractor assembly includes a proximal end with a mount bracket and a custom shaped distal end.1.

[0192] In some embodiments, the techniques described herein relate to a sliding access tubular retractor for performing minimally invasive surgery, including: a hollow windowed insertion tube capable of accepting a surgical instrument, the hollow windowed insertion tube including a proximal end and a distal end; a first slotted window on one side of the hollow windowed insertion tube; a second slotted window on an opposite side of the hollow windowed insertion tube; a first sliding panel configured to slide along a length of the hollow windowed insertion tube to open or close the first slotted window; a second sliding panel configured to slide along the length of the hollow windowed insertion tube to open or close the second slotted window; and an interchangeable custom-shaped distal end configured to fit a targeted surgical site.

[0193] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the proximal end includes a mount bracket.

[0194] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to be retracted upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube.

[0195] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to provide one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end.

[0196] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the interchangeable custom-shaped distal end is configured to be fitted with pre-designed shapes to fit the targeted surgical site.

[0197] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the hollow windowed insertion tube is capable of accepting the surgical instrument in a hollow portion of the hollow windowed insertion tube.PCT ApplicationDocket No.: 408477-502001 WO

[0198] In some embodiments, the techniques described herein relate to a method for performing minimally invasive surgery using a sliding access tubular retractor, the method including: inserting the sliding access tubular retractor into a tissue of a subject, wherein the sliding access tubular retractor includes a hollow windowed insertion tube having a proximal end, a distal end, a first slotted window on one side of the hollow windowed insertion tube, a second slotted window on an opposite side of the hollow windowed insertion tube, a first sliding panel, and a second sliding panel; sliding the first sliding panel and the second sliding panel along a length of the hollow windowed insertion tube to close the first slotted window and the second slotted window during insertion; retracting at least one of the first sliding panel or the second sliding panel along the length of the hollow windowed insertion tube to open at least one of the first slotted window or the second slotted window, thereby providing access to a targeted surgical site at the distal end; wherein a surgeon performing the surgery can access either side of the sliding access tubular retractor by using either one of the first sliding panel and / or the second sliding panel; and interchangeably fitting the distal end with a customshaped distal end to fit the targeted surgical site.

[0199] According to some aspects, the techniques described herein relate to a method, wherein retracting at least one of the first sliding panel or the second sliding panel includes retracting the at least one of the first sliding panel or the second sliding panel upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube.

[0200] In some embodiments, the techniques described herein relate to a method, wherein retracting at least one of the first sliding panel or the second sliding panel provides one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end.

[0201] According to some aspects, the techniques described herein relate to a method, wherein interchangeably fitting the distal end with the custom-shaped distal end includes fitting the distal end with pre-designed shapes to fit the targeted surgical site.

[0202] In some embodiments, the techniques described herein relate to a method, further including accepting a surgical instrument in a hollow portion of the hollow windowed insertion tube.

[0203] According to some aspects, the techniques described herein relate to a method, wherein inserting the sliding access tubular retractor into the tissue of the subject includes inserting the distal end first into the tissue.

[0204] In some embodiments, the techniques described herein relate to a method, wherein the proximal end includes a mount bracket.

[0205] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to slide independently of each other.PCT ApplicationDocket No.: 408477-502001 WO

[0206] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube.

[0207] According to some aspects, the techniques described herein relate to a method, wherein sliding the first sliding panel and the second sliding panel includes sliding the first sliding panel and the second sliding panel independently of each other.

[0208] In some embodiments, the techniques described herein relate to a method, wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube.

[0209] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube.

[0210] In some embodiments, the techniques described herein relate to a method, wherein interchangeably fitting the distal end with the custom-shaped distal end includes removably attaching the custom-shaped distal end to the distal end of the hollow windowed insertion tube.

[0211] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively.

[0212] Additional Technology Discussion Points: Any of the embodiments, claims, or aspects disclosed herein can be combined or inter-combined with any of the discussion points (numbered) below. The technology can be discussed in an overview by the following discussion points:

[0213] Discussion point 1. A sliding access tubular retractor for performing minimally invasive surgery, comprising: a hollow windowed insertion tube capable of accepting a surgical instrument, the hollow windowed insertion tube including a proximal end and a distal end; a first slotted window on one side of the hollow windowed insertion tube; a second slotted window on an opposite side of the hollow windowed insertion tube; a first sliding panel configured to slide along a length of the hollow windowed insertion tube to open or close the first slotted window; a second sliding panel configured to slide along the length of the hollow windowed insertion tube to open or close the second slotted window; and an interchangeable custom-shaped distal end configured to fit a targeted surgical site.

[0214] Discussion point 2. The sliding access tubular retractor of discussion point 1 , wherein the proximal end includes a mount bracket configured to secure the sliding access tubular retractor to a surgical table or other stable structure during the minimally invasive surgery, thereby providing stability and support to the sliding access tubular retractor throughout thePCT ApplicationDocket No.: 408477-502001 WO surgical procedure, and wherein the mount bracket is adjustable to allow for precise positioning of the sliding access tubular retractor relative to the targeted surgical site.

[0215] Discussion point 3. The sliding access tubular retractor of discussion point 1 , wherein the first sliding panel and the second sliding panel are configured to be retracted upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube, thereby allowing the surgeon to adjust the size and position of the first slotted window and the second slotted window during the minimally invasive surgery, and wherein the first sliding panel and the second sliding panel are configured to slide independently of each other, allowing for asymmetric positioning of the first slotted window and the second slotted window.

[0216] Discussion point 4. The sliding access tubular retractor of discussion point 1 , wherein the first sliding panel and the second sliding panel are configured to provide one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end, thereby enabling the surgeon to perform the minimally invasive surgery with improved visibility and maneuverability, and wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, providing extensive access to the targeted surgical site along the length of the sliding access tubular retractor.

[0217] Discussion point 5. The sliding access tubular retractor of discussion point 1 , wherein the interchangeable custom-shaped distal end is configured to be fitted with pre-designed shapes to fit the targeted surgical site, thereby allowing the sliding access tubular retractor to be adapted to various anatomical locations and surgical procedures, and wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube, allowing for quick and easy exchange of the custom-shaped distal end during the minimally invasive surgery.

[0218] Discussion point 6. The sliding access tubular retractor of discussion point 1 , wherein the hollow windowed insertion tube is capable of accepting the surgical instrument in a hollow portion of the hollow windowed insertion tube, thereby enabling the surgeon to insert and manipulate the surgical instrument through the sliding access tubular retractor during the minimally invasive surgery, and wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively, providing access to the targeted surgical site through the first slotted window and the second slotted window during the minimally invasive surgery.

[0219] Discussion point 7. A method for performing minimally invasive surgery using a sliding access tubular retractor, the method comprising: inserting the sliding access tubular retractor into a tissue of a subject, wherein the sliding access tubular retractor comprises a hollow windowed insertion tube having a proximal end, a distal end, a first slotted window on one side of the hollow windowed insertion tube, a second slotted window on an opposite side of thePCT ApplicationDocket No.: 408477-502001 WO hollow windowed insertion tube, a first sliding panel, and a second sliding panel; sliding the first sliding panel and the second sliding panel along a length of the hollow windowed insertion tube to close the first slotted window and the second slotted window during insertion; retracting at least one of the first sliding panel or the second sliding panel along the length of the hollow windowed insertion tube to open at least one of the first slotted window or the second slotted window, thereby providing access to a targeted surgical site at the distal end; wherein a surgeon performing the surgery can access either side of the sliding access tubular retractor by using either one of the first sliding panel and / or the second sliding panel; and interchangeably fitting the distal end with a custom-shaped distal end to fit the targeted surgical site.

[0220] Discussion point 8. The method of discussion point 7, wherein retracting at least one of the first sliding panel or the second sliding panel comprises retracting the at least one of the first sliding panel or the second sliding panel upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube, thereby allowing the surgeon to adjust the size and position of the first slotted window and the second slotted window during the minimally invasive surgery, and wherein the first sliding panel and the second sliding panel are configured to slide independently of each other, allowing for asymmetric positioning of the first slotted window and the second slotted window, thereby providing the surgeon with enhanced flexibility in accessing the targeted surgical site from various angles and positions.

[0221] Discussion point 9. The method of discussion point 7, wherein retracting at least one of the first sliding panel or the second sliding panel provides one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end, thereby enabling the surgeon to perform the minimally invasive surgery with improved visibility and maneuverability, and wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, providing extensive access to the targeted surgical site along the length of the sliding access tubular retractor, thereby allowing the surgeon to perform the minimally invasive surgery with increased precision and control.

[0222] Discussion point 10. The method of discussion point 7, wherein interchangeably fitting the distal end with the custom-shaped distal end comprises fitting the distal end with predesigned shapes to fit the targeted surgical site, thereby allowing the sliding access tubular retractor to be adapted to various anatomical locations and surgical procedures, and wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube, allowing for quick and easy exchange of the custom-shaped distal end during the minimally invasive surgery, thereby enabling the surgeon to adapt the sliding access tubular retractor to changing surgical conditions and requirements.PCT ApplicationDocket No.: 408477-502001 WO

[0223] Discussion point 11 . The method of discussion point 7, further comprising accepting a surgical instrument in a hollow portion of the hollow windowed insertion tube, thereby enabling the surgeon to insert and manipulate the surgical instrument through the sliding access tubular retractor during the minimally invasive surgery, and wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively, providing access to the targeted surgical site through the first slotted window and the second slotted window during the minimally invasive surgery, thereby allowing the surgeon to perform the minimally invasive surgery with increased efficiency and effectiveness.

[0224] Discussion point 12. The method of discussion point 7, wherein inserting the sliding access tubular retractor into the tissue of the subject comprises inserting the distal end first into the tissue, thereby facilitating the placement of the sliding access tubular retractor at the targeted surgical site, and wherein the proximal end includes a mount bracket configured to secure the sliding access tubular retractor to a surgical table or other stable structure during the minimally invasive surgery, allowing for precise positioning of the sliding access tubular retractor relative to the targeted surgical site, thereby enhancing the stability and maneuverability of the sliding access tubular retractor during the minimally invasive surgery.

[0225] Discussion point 13. The method of discussion point 7, wherein the proximal end includes a mount bracket configured to secure the sliding access tubular retractor to a surgical table or other stable structure during the minimally invasive surgery, thereby providing stability and support to the sliding access tubular retractor throughout the surgical procedure, and wherein inserting the sliding access tubular retractor into the tissue of the subject comprises inserting the distal end first into the tissue, allowing for precise placement of the sliding access tubular retractor at the targeted surgical site, thereby minimizing tissue damage and enhancing the accuracy of the minimally invasive surgery.

[0226] Discussion point 14. The sliding access tubular retractor of discussion point 1 , wherein the first sliding panel and the second sliding panel are configured to slide independently of each other, thereby allowing the surgeon to adjust the size and position of the first slotted window and the second slotted window independently during the minimally invasive surgery, and wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, providing extensive access to the targeted surgical site along the length of the sliding access tubular retractor, thereby enabling the surgeon to perform the minimally invasive surgery with increased flexibility and adaptability.

[0227] Discussion point 15. The sliding access tubular retractor of discussion point 1 , wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, thereby providing extensive access to thePCT ApplicationDocket No.: 408477-502001 WO targeted surgical site along the length of the sliding access tubular retractor, and wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube, allowing for quick and easy exchange of the custom-shaped distal end during the minimally invasive surgery, thereby enabling the surgeon to adapt the sliding access tubular retractor to various anatomical locations and surgical procedures with increased efficiency and effectiveness.

[0228] Discussion point 16. The method of discussion point 7, wherein sliding the first sliding panel and the second sliding panel comprises sliding the first sliding panel and the second sliding panel independently of each other, thereby allowing the surgeon to adjust the size and position of the first slotted window and the second slotted window independently during the minimally invasive surgery, and wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, providing extensive access to the targeted surgical site along the length of the sliding access tubular retractor, thereby enabling the surgeon to perform the minimally invasive surgery with increased precision and control.

[0229] Discussion point 17. The method of discussion point 7, wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube, thereby providing extensive access to the targeted surgical site along the length of the sliding access tubular retractor during the minimally invasive surgery, and wherein interchangeably fitting the distal end with the custom-shaped distal end comprises removably attaching the custom-shaped distal end to the distal end of the hollow windowed insertion tube, allowing for quick and easy exchange of the custom-shaped distal end during the minimally invasive surgery, thereby enabling the surgeon to adapt the sliding access tubular retractor to changing surgical conditions and requirements with increased flexibility and adaptability.

[0230] Discussion point 18. The sliding access tubular retractor of discussion point 1 , wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube, thereby allowing the surgeon to easily switch between different custom-shaped distal ends to accommodate various anatomical locations and surgical procedures, and wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively, providing access to the targeted surgical site through the first slotted window and the second slotted window during the minimally invasive surgery, thereby enabling the surgeon to perform the minimally invasive surgery with increased efficiency and effectiveness.

[0231] Discussion point 19. The method of discussion point 7, wherein interchangeably fitting the distal end with the custom-shaped distal end comprises removably attaching the custom-PCT ApplicationDocket No.: 408477-502001 WO shaped distal end to the distal end of the hollow windowed insertion tube, thereby allowing the surgeon to easily switch between different custom-shaped distal ends to accommodate various anatomical locations and surgical procedures during the minimally invasive surgery, and wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively, providing access to the targeted surgical site through the first slotted window and the second slotted window during the minimally invasive surgery, thereby enabling the surgeon to perform the minimally invasive surgery with increased precision and control.

[0232] Discussion point 20. The sliding access tubular retractor of discussion point 1 , wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively, thereby providing access to the targeted surgical site through the first slotted window and the second slotted window during the minimally invasive surgery, and wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube, allowing for quick and easy exchange of the custom-shaped distal end during the minimally invasive surgery, thereby enabling the surgeon to adapt the sliding access tubular retractor to changing surgical conditions and requirements with increased flexibility and adaptability.

[0233] Further in a discussion, study or a reading of the details, features, embodiments, aspects, and / or examples of the technology disclosed herein, any of the features, embodiments, aspects, and / or examples herein can be inter-combined (or inter-discussed) with the example details listed below:

[0234] Detail 1 : A tubular retractor for minimally invasive spinal surgeries, comprising: a proximal end assembly comprising removable shims, wherein removal of the removable shims provides access windows running along a length of the tubular retractor, the proximal end assembly further comprising a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims; an adjustable distal end assembly comprising telescoping or extendable segments configured to lengthen or shorten the tubular retractor for accommodating different surgical depths, the adjustable distal end assembly further comprising one or more locking mechanisms to secure the telescoping or extendable segments at a desired length; and a distal tip configured to provide a beveled, contoured or cylindrical shape for contacting tissue surrounding a surgical site, the distal tip optionally being transparent or translucent to allow visualization of the surgical site; wherein the tubular retractor is adjustable in length either during or prior to a surgery, and wherein the tubular retractor optionally comprises radiopaque markers to facilitate visualization under imaging.

[0235] Detail 2: The tubular retractor of detail 1 , wherein the access windows extend from the collar along the length of the main tube when the removable shims are removed, the accessPCT ApplicationDocket No.: 408477-502001 WO windows having a width and length optimized for instrument access and visualization of the surgical site, and wherein the access windows are configured to be selectively opened or closed during the surgery to protect surrounding tissue and maintain insufflation.

[0236] Detail 3: The tubular retractor of detail 1 , wherein the removable shims are configured to be removed either during or prior to the surgery to provide the access windows, the removable shims being made of a radiolucent material to enhance intraoperative imaging, and wherein the removable shims are securely attached to the main tube and collar but easily removable without disrupting the surgical procedure.

[0237] Detail 4: The tubular retractor of detail 1 , wherein the adjustable distal end assembly comprises one or more telescoping segments, each telescoping segment having a graduated scale to indicate the length of extension and a locking mechanism to secure the segment at a desired length, and wherein the telescoping segments are made of a biocompatible material with low friction surfaces to facilitate smooth extension and retraction.

[0238] Detail 5: The tubular retractor of detail 1 , wherein the adjustable distal end assembly comprises one or more extendable segments, each extendable segment comprising threads and / or a flexible membrane or bellows to allow lengthening and shortening of the segment, and wherein the extendable segments are made of a durable, puncture- resistant material to prevent damage during insertion and manipulation.

[0239] Detail 6: The tubular retractor of detail 1 , wherein the distal tip is at a far distal end of the adjustable distal end assembly, the distal tip being detachable and interchangeable with other distal tips of different shapes and sizes to accommodate various anatomies and surgical procedures, and wherein the distal tip is made of a soft, atraumatic material to prevent tissue damage.

[0240] Detail 7: The tubular retractor of detail 1 , wherein the distal tip is configured to provide the beveled shape for contacting the tissue surrounding the surgical site, the beveled shape having an angle optimized for tissue retraction and visualization, and wherein the beveled shape is oriented to direct light from the lighting system towards the surgical site.

[0241] Detail 8: The tubular retractor of detail 1 , wherein the distal tip is configured to provide the contoured shape for contacting the tissue surrounding the surgical site, the contoured shape having a curved or tapered profile to match the natural contours of the tissue, and wherein the contoured shape is designed to distribute retraction forces evenly and prevent tissue trauma.

[0242] Detail 9: The tubular retractor of detail 1 , wherein the distal tip is configured to provide the cylindrical shape for contacting the tissue surrounding the surgical site, the cylindrical shape having a smooth, rounded surface to facilitate insertion and minimize tissue disruption, and wherein the cylindrical shape is sized to fit securely within the surgical incision and maintain a clear working channel.PCT ApplicationDocket No.: 408477-502001 WO

[0243] Detail 10: The tubular retractor of detail 1 , wherein the tubular retractor is made of at least one of stainless steel, titanium, aluminum, plastic, polymer, ceramic, composite material, carbon fiber, glass, Polyetherimide (PEI), Polyphenylsulfone (PPSLI), Polysulfone (PSU), Polyetheretherketone (PEEK), Polyaryletherketone (PAEK), Polyetherketoneketone (PEKK), Polyetherketone (PEK), Polyetherketoneetherketoneketone (PEKEKK), or any combination thereof, the material being selected for its strength, durability, biocompatibility, and radiolucency, and wherein the material is suitable for sterilization and reuse.

[0244] Detail 11 : The tubular retractor of detail 1 , wherein the tubular retractor further comprises a lighting system to illuminate the surgical site, the lighting system comprising one or more light sources integrated into the proximal end assembly, adjustable distal end assembly, or distal tip, and wherein the lighting system is adjustable in brightness and color temperature to optimize visualization and minimize glare or shadows.

[0245] Detail 12: A method of performing minimally invasive spinal surgery, comprising: providing a tubular retractor comprising a proximal end assembly with removable shims, an adjustable distal end assembly, and a distal tip, the proximal end assembly further comprising a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims, the adjustable distal end assembly further comprising one or more locking mechanisms, and the distal tip optionally being transparent or translucent; adjusting a length of the tubular retractor by lengthening or shortening the adjustable distal end assembly and securing the adjustable distal end assembly at a desired length using the one or more locking mechanisms; removing the removable shims from the proximal end assembly to provide access windows running along a length of the tubular retractor, the access windows optionally extending from the collar along the length of the main tube; contacting tissue surrounding a surgical site with the distal tip, the distal tip having a beveled, contoured or cylindrical shape; and optionally visualizing the surgical site through the transparent or translucent distal tip and / or using radiopaque markers on the tubular retractor under imaging.

[0246] Detail 13: The method of detail 12, wherein adjusting the length of the tubular retractor comprises lengthening or shortening the adjustable distal end assembly to accommodate a depth of the surgical site, the depth being determined by preoperative imaging or intraoperative measurements, and wherein the length adjustment is performed gradually and precisely to avoid sudden movements or excessive forces on the tissue.

[0247] Detail 14: The method of detail 12, wherein removing the removable shims comprises removing the removable shims either during or prior to the surgery, the removal being performed using a specialized tool or by hand, and wherein the removal is done carefully to avoid dislodging or damaging the tubular retractor or surrounding tissue.PCT ApplicationDocket No.: 408477-502001 WO

[0248] Detail 15: The method of detail 12, wherein the adjustable distal end assembly comprises one or more telescoping segments, and wherein adjusting the length of the tubular retractor comprises unlocking the telescoping segments, extending or retracting the segments to the desired length, and locking the segments securely in place using the locking mechanisms.

[0249] Detail 16: The method of detail 12, wherein the adjustable distal end assembly comprises one or more extendable segments, and wherein adjusting the length of the tubular retractor comprises applying a force to the extendable segments to lengthen or shorten them, the force being applied gradually and evenly to prevent damage to the segments or surrounding tissue.

[0250] Detail 17: The method of detail 12, wherein the distal tip is at a far distal end of the adjustable distal end assembly, and wherein contacting the tissue surrounding the surgical site with the distal tip comprises advancing the tubular retractor through the incision until the distal tip reaches the desired depth and orientation, the advancement being guided by imaging or tactile feedback.

[0251] Detail 18: The method of detail 12, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the beveled shape of the distal tip, the beveled shape being oriented to retract the tissue away from the surgical site and direct light from the lighting system towards the site, and wherein the beveled shape is used to dissect through soft tissue layers to reach the target anatomy.

[0252] Detail 19: The method of detail 12, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the contoured or cylindrical shape of the distal tip, the contoured or cylindrical shape being selected to match the natural contours of the tissue and distribute retraction forces evenly, and wherein the contoured or cylindrical shape is rotated or swept to create a larger working space within the incision.

[0253] Detail 20: The method of detail 12, further comprising illuminating the surgical site using a lighting system on the tubular retractor, the lighting system comprising one or more light sources integrated into the proximal end assembly, adjustable distal end assembly, or distal tip, and wherein the lighting system is adjusted in brightness and color temperature to optimize visualization and minimize glare or shadows.

[0254] Detail 21 : The method of detail 12, wherein the tubular retractor is made of at least one of stainless steel, titanium, aluminum, plastic, polymer, ceramic, composite material, carbon fiber, glass, Polyetherimide (PEI), Polyphenylsulfone (PPSLI), Polysulfone (PSU), Polyetheretherketone (PEEK), Polyaryletherketone (PAEK), Polyetherketoneketone (PEKK), Polyetherketone (PEK), Polyetherketoneetherketoneketone (PEKEKK), or any combination thereof, the material being selected for its strength, durability, biocompatibility, andPCT ApplicationDocket No.: 408477-502001 WO radiolucency, and wherein the tubular retractor is sterilized before use and disposed of or resterilized after use according to hospital protocols.

[0255] Detail 22: A tubular retractor for minimally invasive spinal surgeries, comprising: a proximal end assembly comprising removable shims, wherein removal of the removable shims provides access windows running along a length of the tubular retractor, the proximal end assembly further comprising a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims, and wherein the main tube and collar are made of a rigid, biocompatible material such as stainless steel or titanium alloy, with a smooth inner surface to facilitate passage of surgical instruments; an adjustable distal end assembly comprising telescoping or extendable segments configured to lengthen or shorten the tubular retractor for accommodating different surgical depths, the adjustable distal end assembly further comprising one or more locking mechanisms to secure the telescoping or extendable segments at a desired length, and wherein the telescoping or extendable segments are made of a strong, lightweight material such as carbon fiber or PEEK, with a graduated scale or markings to indicate the length of extension; a distal tip configured to provide a beveled, contoured or cylindrical shape for contacting tissue surrounding a surgical site, the distal tip optionally being transparent or translucent to allow visualization of the surgical site, and wherein the distal tip is made of a soft, flexible material such as silicone or low-durometer polyurethane, with a smooth, atraumatic surface to minimize tissue trauma; wherein the tubular retractor is adjustable in length either during or prior to a surgery, with a total length ranging from about 50 mm to about 200 mm and a diameter ranging from about 10 mm to about 30 mm, and wherein the tubular retractor optionally comprises radiopaque markers to facilitate visualization under imaging, the radiopaque markers being made of a high-density material such as tantalum or tungsten and placed at strategic locations along the length of the retractor.

[0256] Detail 23: The tubular retractor of detail 22, wherein the access windows extend from the collar along the length of the main tube when the removable shims are removed, the access windows having a width ranging from about 5 mm to about 20 mm and a length ranging from about 30 mm to about 150 mm, and wherein the access windows are configured to be selectively opened or closed during the surgery using a sliding or rotating mechanism, with a locking feature to maintain the desired window configuration.

[0257] Detail 24: The tubular retractor of detail 22, wherein the removable shims are configured to be removed either during or prior to the surgery to provide the access windows, the removable shims being made of a radiolucent material such as carbon fiber or PEEK to enhance intraoperative imaging, and wherein the removable shims are securely attached to the main tube and collar using a snap-fit, tongue-and-groove, or dovetail mechanism, with a quick-release feature to allow easy removal.PCT ApplicationDocket No.: 408477-502001 WO

[0258] Detail 25: The tubular retractor of detail 22, wherein the adjustable distal end assembly comprises one or more telescoping segments, each telescoping segment having a graduated scale or markings to indicate the length of extension, with a resolution ranging from about 1 mm to about 10 mm, and a locking mechanism to secure the segment at a desired length, the locking mechanism being a threaded collar, a cam lock, or a ratcheting mechanism, and wherein the telescoping segments are made of a biocompatible material with low friction surfaces such as PTFE or LIHMWPE to facilitate smooth extension and retraction.

[0259] Detail 26: The tubular retractor of detail 22, wherein the adjustable distal end assembly comprises one or more extendable segments, each extendable segment comprising a flexible membrane or bellows made of a durable, puncture-resistant material such as reinforced silicone or polyurethane, with a wall thickness ranging from about 0.5 mm to about 2 mm, and wherein the extendable segments are configured to lengthen or shorten by at least 50% of their original length, with a maximum extension length ranging from about 50 mm to about 150 mm.

[0260] Detail 27: The tubular retractor of detail 22, wherein the distal tip is at a far distal end of the adjustable distal end assembly, the distal tip being detachable and interchangeable with other distal tips of different shapes and sizes, with a quick-connect mechanism such as a bayonet mount or a threaded connection, and wherein the distal tip is made of a soft, atraumatic material with a durometer ranging from about 20A to about 60A, and a wall thickness ranging from about 1 mm to about 5 mm.

[0261] Detail 28: The tubular retractor of detail 22, wherein the distal tip is configured to provide the beveled shape for contacting the tissue surrounding the surgical site, the beveled shape having an angle ranging from about 30 degrees to about 60 degrees relative to the longitudinal axis of the retractor, and wherein the beveled shape is oriented to direct light from the lighting system towards the surgical site, with a reflective or mirrored surface to enhance illumination.

[0262] Detail 29: The tubular retractor of detail 22, wherein the distal tip is configured to provide the contoured shape for contacting the tissue surrounding the surgical site, the contoured shape having a curved or tapered profile with a radius of curvature ranging from about 5 mm to about 20 mm, and wherein the contoured shape is designed to distribute retraction forces evenly over a larger surface area, with a textured or ribbed surface to enhance grip and prevent slippage.

[0263] Detail 30: The tubular retractor of detail 22, wherein the distal tip is configured to provide the cylindrical shape for contacting the tissue surrounding the surgical site, the cylindrical shape having a smooth, rounded surface with a diameter ranging from about 5 mm to about 20 mm, and wherein the cylindrical shape is sized to fit securely within the surgicalPCT ApplicationDocket No.: 408477-502001 WO incision, with an inflatable cuff or balloon to enhance retention and maintain a clear working channel.

[0264] Detail 31 : The tubular retractor of detail 22, wherein the tubular retractor is made of at least one of stainless steel, titanium, aluminum, plastic, polymer, ceramic, composite material, carbon fiber, glass, Polyetherimide (PEI), Polyphenylsulfone (PPSLI), Polysulfone (PSU), Polyetheretherketone (PEEK), Polyaryletherketone (PAEK), Polyetherketoneketone (PEKK), Polyetherketone (PEK), Polyetherketoneetherketoneketone (PEKEKK), or any combination thereof, the material being selected for its strength, durability, biocompatibility, and radiolucency, with a modulus of elasticity ranging from about 1 GPa to about 200 GPa, and wherein the material is suitable for sterilization using steam, gamma radiation, or chemical methods, with a maximum temperature tolerance ranging from about 100°C to about 200°C.

[0265] Detail 32: The tubular retractor of detail 22, wherein the tubular retractor further comprises a lighting system to illuminate the surgical site, the lighting system comprising one or more light sources such as LEDs, fiber optics, or electroluminescent panels, with a brightness ranging from about 10,000 lux to about 100,000 lux and a color temperature ranging from about 3000K to about 6000K, and wherein the lighting system is adjustable in brightness and color temperature using a remote control or a voice-activated system, with a battery life ranging from about 2 hours to about 8 hours.

[0266] Detail 33: A method of performing minimally invasive spinal surgery, comprising: providing a tubular retractor comprising a proximal end assembly with removable shims, an adjustable distal end assembly, and a distal tip, the proximal end assembly further comprising a main tube and a collar at a proximal end of the main tube, the main tube and the collar comprising the removable shims, the adjustable distal end assembly further comprising one or more locking mechanisms, and the distal tip optionally being transparent or translucent; adjusting a length of the tubular retractor by lengthening or shortening the adjustable distal end assembly and securing the adjustable distal end assembly at a desired length using the one or more locking mechanisms, the length adjustment being performed using a manual or powered mechanism, with a maximum extension speed ranging from about 5 mm / s to about 20 mm / s; removing the removable shims from the proximal end assembly to provide access windows running along a length of the tubular retractor, the access windows optionally extending from the collar along the length of the main tube, the removal being performed using a specialized tool or by hand, with a maximum removal force ranging from about 10 N to about 50 N; contacting tissue surrounding a surgical site with the distal tip, the distal tip having a beveled, contoured or cylindrical shape, the contact being made using a gentle, gradual motion to minimize tissue trauma, with a maximum insertion force ranging from about 5 N to about 20 N; and optionally visualizing the surgical site through the transparent or translucent distal tip and / or using radiopaque markers on the tubular retractor under imaging, thePCT ApplicationDocket No.: 408477-502001 WO visualization being enhanced using a light source, a magnifying lens, or a camera system, with a resolution ranging from about 1 megapixel to about 10 megapixels.

[0267] Detail 34: The method of detail 33, wherein adjusting the length of the tubular retractor comprises lengthening or shortening the adjustable distal end assembly to accommodate a depth of the surgical site, the depth being determined by preoperative imaging such as X-ray, CT, or MRI, or by intraoperative measurements using a depth gauge or a probe, and wherein the length adjustment is performed gradually and precisely using a motorized or hydraulic mechanism, with a length resolution ranging from about 0.1 mm to about 1 mm.

[0268] Detail 35: The method of detail 33, wherein removing the removable shims comprises removing the removable shims either during or prior to the surgery, the removal being performed using a specialized tool such as a shim remover or a pliers, or by hand using a gripping surface or a pull tab, and wherein the removal is done carefully and sequentially to avoid dislodging or damaging the tubular retractor or surrounding tissue, with a maximum removal time ranging from about 10 seconds to about 60 seconds.

[0269] Detail 36: The method of detail 33, wherein the adjustable distal end assembly comprises one or more telescoping segments, and wherein adjusting the length of the tubular retractor comprises unlocking the telescoping segments using a release button or a lever, extending or retracting the segments to the desired length using a manual or powered mechanism, and locking the segments securely in place using the locking mechanisms, the locking being performed using a twisting, clamping, or snapping motion, with a maximum locking force ranging from about 20 N to about 100 N.

[0270] Detail 37: The method of detail 33, wherein the adjustable distal end assembly comprises one or more extendable segments, and wherein adjusting the length of the tubular retractor comprises applying a force to the extendable segments using a manual or powered mechanism to lengthen or shorten them, the force being applied gradually and evenly using a compression spring, a pneumatic cylinder, or a hydraulic piston, with a maximum extension force ranging from about 10 N to about 50 N and a maximum retraction force ranging from about 5 N to about 20 N.

[0271] Detail 38: The method of detail 33, wherein the distal tip is at a far distal end of the adjustable distal end assembly, and wherein contacting the tissue surrounding the surgical site with the distal tip comprises advancing the tubular retractor through the incision using a manual or motorized mechanism until the distal tip reaches the desired depth and orientation, the advancement being guided by imaging such as fluoroscopy, ultrasound, or endoscopy, or by tactile feedback using a force sensor or a pressure sensor, with a maximum advancement force ranging from about 5 N to about 20 N.

[0272] Detail 39: The method of detail 33, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the beveled shape of thePCT ApplicationDocket No.: 408477-502001 WO distal tip, the beveled shape being oriented to retract the tissue away from the surgical site at an angle ranging from about 30 degrees to about 60 degrees, and to direct light from the lighting system towards the site at an angle ranging from about 10 degrees to about 45 degrees, and wherein the beveled shape is used to dissect through soft tissue layers using a sweeping or rotational motion, with a maximum dissection force ranging from about 2 N to about 10 N.

[0273] Detail 40: The method of detail 33, wherein contacting the tissue surrounding the surgical site with the distal tip comprises contacting the tissue with the contoured or cylindrical shape of the distal tip, the contoured or cylindrical shape being selected to match the natural contours of the tissue with a radius of curvature ranging from about 5 mm to about 20 mm, and to distribute retraction forces evenly over a surface area ranging from about 50 mmA2 to about 500 mmA2, and wherein the contoured or cylindrical shape is rotated or swept through an angle ranging from about 30 degrees to about 180 degrees to create a larger working space within the incision, with a maximum sweep rate ranging from about 10 degrees / s to about 45 degrees / s.

[0274] Detail 41 : The method of detail 33, further comprising illuminating the surgical site using a lighting system on the tubular retractor, the lighting system comprising one or more light sources such as LEDs, fiber optics, or electroluminescent panels, with a brightness ranging from about 10,000 lux to about 100,000 lux and a color temperature ranging from about 3000K to about 6000K, and wherein the lighting system is adjusted in brightness and color temperature using a remote control or a voice-activated system, with a dimming range from about 10% to about 100% and a color temperature range from about 2500K to about 6500K.

[0275] Detail 42: The method of detail 33, wherein the tubular retractor is made of at least one of stainless steel, titanium, aluminum, plastic, polymer, ceramic, composite material, carbon fiber, glass, Polyetherimide (PEI), Polyphenylsulfone (PPSLI), Polysulfone (PSU), Polyetheretherketone (PEEK), Polyaryletherketone (PAEK), Polyetherketoneketone (PEKK), Polyetherketone (PEK), Polyetherketoneetherketoneketone (PEKEKK), or any combination thereof, the material being selected for its strength, durability, biocompatibility, and radiolucency, with a yield strength ranging from about 50 MPa to about 2000 MPa and a radiolucency ranging from about 50% to about 95%, and wherein the tubular retractor is sterilized before use using steam, gamma radiation, or chemical methods, with a sterility assurance level (SAL) ranging from about 10A-3 to about 10A-6, and disposed of or resterilized after use according to hospital protocols, with a maximum number of reuses ranging from about 10 to about 100.

[0276] Detail 43: A system for performing minimally invasive spinal surgeries, comprising: a tubular retractor comprising a main tube having a collar at one end and an extendable distalPCT ApplicationDocket No.: 408477-502001 WO end, wherein the main tube and the collar comprise one or more removable elements that, when removed at any time, provide one or more access windows from the collar running along a length of the main tube; and wherein the extendable distal end comprises one or more adjustable segments configured to adjust a length of the tubular retractor for varying depths, and wherein a distal end of the one or more adjustable segments is configured to provide a suitable shape for contact with surrounding tissue; and one or more mount arms affixed to the collar, wherein the one or more mount arms are configured to be mounted to a surgical table; wherein the main tube is made of a biocompatible material suitable for surgical use; wherein the collar is configured to provide a secure attachment point for the one or more mount arms; wherein the one or more removable elements are made of a radiolucent material to allow for imaging during the surgery; wherein the one or more access windows are dimensioned to provide adequate surgical access while minimizing tissue damage; wherein the extendable distal end is configured to be lockable at various lengths to maintain a desired retractor length during the surgery; wherein the one or more adjustable segments are made of a flexible material to allow for conformance to patient anatomy; wherein the distal end of the one or more adjustable segments is configured to be atraumatic to prevent tissue damage during insertion and positioning; wherein the one or more mount arms are adjustable to allow for positioning of the tubular retractor at various angles relative to the surgical table; wherein the system further comprises a lighting system configured to provide illumination of the surgical site through the one or more access windows; wherein the system further comprises an irrigation system configured to provide irrigation to the surgical site through the one or more access windows; and / or wherein the system further comprises a suction system configured to provide suction at the surgical site through the one or more access windows.

[0277] Detail 44: The system of detail 43, wherein the collar is located at a proximal end of the main tube; wherein the collar is configured to provide a gripping surface for manual manipulation of the tubular retractor; wherein the collar is configured to be compatible with standard surgical draping techniques; wherein the collar is made of a material that can withstand repeated sterilization processes; wherein the collar is configured to provide a attachment point for a surgical retractor blade; wherein the collar is configured to provide an attachment point for a fiber optic cable to provide illumination to the surgical site; wherein the collar is configured to provide an attachment point for a camera system to allow for visualization of the surgical site; wherein the collar is configured to provide an attachment point for a nerve monitoring system to allow for monitoring of neural structures during the surgery; wherein the collar is configured to provide an attachment point for a guidance system to assist with placement of surgical instruments; wherein the collar is configured to provide an attachment point for a robotic surgical system to allow for robotic assistance during thePCT ApplicationDocket No.: 408477-502001 WO surgery; and / or wherein the collar is configured to be removable and replaceable to allow for different collar configurations to be used with the tubular retractor.

[0278] Detail 45: The system of detail 43, wherein the one or more removable elements comprise one or more removable shims; wherein the one or more removable shims are configured to be stackable to allow for customization of the size and shape of the one or more access windows; wherein the one or more removable shims are configured to be made of a material that can withstand repeated sterilization processes; wherein the one or more removable shims are configured to be color-coded to allow for easy identification of different sizes; wherein the one or more removable shims are configured to be made of a transparent material to allow for visualization of the surgical site through the shims; wherein the one or more removable shims are configured to be made of a material that provides electrical insulation to prevent interference with nerve monitoring systems; wherein the one or more removable shims are configured to be made of a material that is compatible with magnetic resonance imaging (MRI); wherein the one or more removable shims are configured to be made of a material that is compatible with computed tomography (CT) imaging; wherein the one or more removable shims are configured to be made of a material that is compatible with fluoroscopic imaging; wherein the one or more removable shims are configured to be made of a material that is radiopaque to allow for easy visualization during imaging; and / or wherein the one or more removable shims are configured to be made of a material that is echogenic to allow for easy visualization during ultrasound imaging.

[0279] Detail 46: The system of detail 43, wherein the one or more access windows extend from the collar to the extendable distal end and / or extend from the collar along the length of the main tube; wherein the one or more access windows are configured to be sealed with a transparent material to allow for visualization of the surgical site while maintaining sterility; wherein the one or more access windows are configured to be sealed with a material that can be easily removed and replaced during the surgery to allow for access to the surgical site; wherein the one or more access windows are configured to be sealed with a material that is self-sealing to allow for insertion and removal of surgical instruments without compromising sterility; wherein the one or more access windows are configured to be sealed with a material that is resistant to tearing and puncturing during the surgery; wherein the one or more access windows are configured to be sealed with a material that is compatible with standard surgical draping techniques; wherein the one or more access windows are configured to be sealed with a material that is compatible with magnetic resonance imaging (MRI); wherein the one or more access windows are configured to be sealed with a materialPCT ApplicationDocket No.: 408477-502001 WO that is compatible with computed tomography (CT) imaging; wherein the one or more access windows are configured to be sealed with a material that is compatible with fluoroscopic imaging; wherein the one or more access windows are configured to be sealed with a material that is radiopaque to allow for easy visualization during imaging; and / or wherein the one or more access windows are configured to be sealed with a material that is echogenic to allow for easy visualization during ultrasound imaging.

[0280] Detail 47: The system of detail 43, wherein the one or more adjustable segments comprise at least one of telescoping segments or extendable segments; wherein the telescoping segments are configured to be made of a biocompatible material suitable for surgical use; wherein the telescoping segments are configured to be made of a material that can withstand repeated sterilization processes; wherein the telescoping segments are configured to be made of a material that provides sufficient rigidity to maintain the desired length of the tubular retractor during the surgery; wherein the telescoping segments are configured to be made of a material that is radiolucent to allow for imaging during the surgery; wherein the telescoping segments are configured to be made of a material that is compatible with magnetic resonance imaging (MRI); wherein the telescoping segments are configured to be made of a material that is compatible with computed tomography (CT) imaging; wherein the telescoping segments are configured to be made of a material that is compatible with fluoroscopic imaging; wherein the extendable segments are configured to be made of a biocompatible material suitable for surgical use; wherein the extendable segments are configured to be made of a material that can withstand repeated sterilization processes; wherein the extendable segments are configured to be made of a material that provides sufficient flexibility to allow for conformance to patient anatomy; and / or wherein the extendable segments are configured to be made of a material that is radiolucent to allow for imaging during the surgery.

[0281] Detail 48: The system of detail 43, wherein the length of the tubular retractor is adjustable for deeper or shallower surgeries; wherein the length of the tubular retractor is adjustable in increments of 1 mm to allow for precise positioning; wherein the length of the tubular retractor is adjustable in increments of 5 mm to allow for rapid positioning; wherein the length of the tubular retractor is adjustable in increments of 10 mm to allow for gross positioning; wherein the length of the tubular retractor is continuously adjustable to allow for infinite positioning; wherein the length of the tubular retractor is adjustable using a manual adjustment mechanism; wherein the length of the tubular retractor is adjustable using a powered adjustment mechanism; wherein the length of the tubular retractor is adjustable using a remote control system to allow for adjustment from outside the sterile field; wherein the length of the tubular retractor is adjustable using a voice-activated control system to allow forPCT ApplicationDocket No.: 408477-502001 WO hands-free adjustment; wherein the length of the tubular retractor is adjustable using a foot- operated control system to allow for hands-free adjustment; and / or wherein the length of the tubular retractor is automatically adjustable based on feedback from a surgical navigation system to allow for precise positioning relative to patient anatomy.

[0282] Detail 49: The system of detail 43, wherein the length of the tubular retractor is adjustable either during or prior to a surgery; wherein the length of the tubular retractor is adjustable using a locking mechanism to maintain the desired length during the surgery; wherein the locking mechanism is configured to be operated using one hand to allow for easy adjustment during the surgery; wherein the locking mechanism is configured to provide tactile feedback to indicate when the desired length has been achieved; wherein the locking mechanism is configured to provide audible feedback to indicate when the desired length has been achieved; wherein the locking mechanism is configured to provide visual feedback to indicate when the desired length has been achieved; wherein the locking mechanism is configured to be operated using a remote control system to allow for adjustment from outside the sterile field; wherein the locking mechanism is configured to be operated using a voice- activated control system to allow for hands-free adjustment; wherein the locking mechanism is configured to be operated using a foot-operated control system to allow for hands-free adjustment; wherein the locking mechanism is automatically engaged based on feedback from a surgical navigation system to allow for precise positioning relative to patient anatomy; and / or wherein the locking mechanism is automatically disengaged when the tubular retractor is being adjusted to prevent damage to the retractor or patient anatomy.

[0283] Detail 50: The system of detail 43, wherein the suitable shape of the distal end of the one or more adjustable segments comprises at least one of a beveled shape, a contoured shape, or a cylindrical shape; wherein the beveled shape is configured to provide a smooth transition between the tubular retractor and the patient anatomy to minimize tissue damage; wherein the beveled shape is configured to be angled at 30 degrees relative to the longitudinal axis of the tubular retractor to allow for optimal visualization and access to the surgical site; wherein the beveled shape is configured to be angled at 45 degrees relative to the longitudinal axis of the tubular retractor to allow for optimal visualization and access to the surgical site; wherein the beveled shape is configured to be angled at 60 degrees relative to the longitudinal axis of the tubular retractor to allow for optimal visualization and access to the surgical site; wherein the contoured shape is configured to match the curvature of the patient's spine to allow for optimal positioning of the tubular retractor; wherein the contoured shape is configured to be customizable based on preoperative imaging of the patient's spine; wherein the contoured shape is configured to be adjustable during the surgery to allow for optimal positioning of the tubular retractor; wherein the cylindrical shape is configured to provide a uniform cross-section along the length of the tubular retractor to allow for consistentPCT ApplicationDocket No.: 408477-502001 WO visualization and access to the surgical site; wherein the cylindrical shape is configured to be sized to fit within the patient's intervertebral space to allow for direct access to the surgical site; and / or wherein the cylindrical shape is configured to be sized to fit within the patient's intervertebral foramen to allow for direct access to the surgical site.

[0284] Detail 51 : The system of detail 43, wherein the distal end of the one or more adjustable segments is configured to minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be made of a soft and pliable material to minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be coated with a lubricious material to minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be coated with a hydrophilic material to minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be coated with a bioactive material to promote tissue healing; wherein the distal end of the one or more adjustable segments is configured to be equipped with a light source to improve visibility and minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be equipped with a camera to improve visibility and minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be equipped with a sensor to detect nearby structures and minimize tissue damage; wherein the distal end of the one or more adjustable segments is configured to be equipped with a nerve stimulator to detect and avoid neural structures; wherein the distal end of the one or more adjustable segments is configured to be equipped with an ultrasonic transducer to detect and avoid vascular structures; and / or wherein the distal end of the one or more adjustable segments is configured to be equipped with an electrocautery device to coagulate and cut tissue while minimizing collateral damage.

[0285] Detail 52: A kit for performing minimally invasive spinal surgeries, the kit comprising: a tubular retractor for minimally invasive spinal surgeries, the tubular retractor comprising: a proximal end assembly comprising removable shims, wherein removal of the removable shims provides access windows running along a length of the tubular retractor; an adjustable distal end assembly comprising telescoping or extendable segments configured to lengthen or shorten the tubular retractor for accommodating different surgical depths; and a distal tip configured to provide a beveled, contoured or cylindrical shape for contacting tissue surrounding a surgical site; wherein the tubular retractor is adjustable in length either during or prior to a surgery; wherein the kit further comprises a plurality of different sizes of the tubular retractor to accommodate different patient anatomies and surgical procedures; wherein the kit further comprises a plurality of different shapes of the distal tip to accommodate different surgical approaches and techniques; wherein the kit further comprises a plurality of different materials for the removable shims to accommodate different imaging modalities and surgical techniques; wherein the kit further comprises a plurality of different lengths and diameters ofPCT ApplicationDocket No.: 408477-502001 WO the telescoping or extendable segments to accommodate different surgical depths and patient anatomies; wherein the kit further comprises a plurality of different types and sizes of surgical instruments configured to be used with the tubular retractor; wherein the kit further comprises a surgical drape configured to be used with the tubular retractor to maintain sterility during the surgery; wherein the kit further comprises a surgical irrigation system configured to be used with the tubular retractor to provide irrigation to the surgical site; wherein the kit further comprises a surgical suction system configured to be used with the tubular retractor to provide suction at the surgical site; wherein the kit further comprises a surgical lighting system configured to be used with the tubular retractor to provide illumination to the surgical site; and / or wherein the kit further comprises a surgical navigation system configured to be used with the tubular retractor to provide guidance and tracking during the surgery.

[0286] Detail 53: The kit of detail 52, wherein the removable shims are configured to be removed at any time to provide the access windows; wherein the removable shims are configured to be reattached at any time to close the access windows; wherein the removable shims are configured to be partially removed to provide customizable access windows; wherein the removable shims are configured to be made of a radiolucent material to allow for intraoperative imaging; wherein the removable shims are configured to be made of a radiopaque material to provide contrast during intraoperative imaging; wherein the removable shims are configured to be made of a material that is compatible with magnetic resonance imaging (MRI); wherein the removable shims are configured to be made of a material that is compatible with computed tomography (CT) imaging; wherein the removable shims are configured to be made of a material that is compatible with fluoroscopic imaging; wherein the removable shims are configured to be made of a material that is compatible with ultrasound imaging; wherein the removable shims are configured to be made of a material that is transparent to allow for visualization of the surgical site; and / or wherein the removable shims are configured to be made of a material that is opaque to provide a barrier between the surgical site and the surrounding tissue.

[0287] Detail 54: The kit of detail 52, wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor for deeper or shallower surgeries; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor in increments of 1 mm; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor in increments of 5 mm; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor in increments of 10 mm; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor continuously; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor using a manual mechanism; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor using a poweredPCT ApplicationDocket No.: 408477-502001 WO mechanism; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor using a remote control mechanism; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor using a voice-activated mechanism; wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor using a foot-operated mechanism; and / or wherein the adjustable distal end assembly is configured to automatically adjust the length of the tubular retractor based on feedback from a surgical navigation system.

[0288] Detail 55: The kit of detail 52, wherein the adjustable distal end assembly is configured to adjust the length of the tubular retractor either during or prior to a surgery; wherein the adjustable distal end assembly is configured to lock the length of the tubular retractor during the surgery; wherein the adjustable distal end assembly is configured to unlock the length of the tubular retractor during the surgery; wherein the adjustable distal end assembly is configured to provide tactile feedback when adjusting the length of the tubular retractor; wherein the adjustable distal end assembly is configured to provide audible feedback when adjusting the length of the tubular retractor; wherein the adjustable distal end assembly is configured to provide visual feedback when adjusting the length of the tubular retractor; wherein the adjustable distal end assembly is configured to be adjusted using a single hand; wherein the adjustable distal end assembly is configured to be adjusted using a tool; wherein the adjustable distal end assembly is configured to be adjusted using a robotic system; wherein the adjustable distal end assembly is configured to be adjusted using a navigation system; and / or wherein the adjustable distal end assembly is configured to be adjusted based on real-time imaging of the surgical site.

[0289] Detail 56: The kit of detail 52, wherein the distal tip is configured to minimize tissue damage when contacting the tissue surrounding the surgical site; wherein the distal tip is configured to be made of a soft and pliable material to minimize tissue damage; wherein the distal tip is configured to be coated with a lubricious material to minimize tissue damage; wherein the distal tip is configured to be coated with a hydrophilic material to minimize tissue damage; wherein the distal tip is configured to be coated with a bioactive material to promote tissue healing; wherein the distal tip is configured to be equipped with a light source to improve visibility and minimize tissue damage; wherein the distal tip is configured to be equipped with a camera to improve visibility and minimize tissue damage; wherein the distal tip is configured to be equipped with a sensor to detect nearby structures and minimize tissue damage; wherein the distal tip is configured to be equipped with a nerve stimulator to detect and avoid neural structures; wherein the distal tip is configured to be equipped with an ultrasonic transducer to detect and avoid vascular structures; and / or wherein the distal tip is configured to be equipped with an electrocautery device to coagulate and cut tissue while minimizing collateral damage.PCT ApplicationDocket No.: 408477-502001 WO

[0290] Detail 57: The kit of detail 52, further comprising instructions for using the tubular retractor to access a surgical site through the access windows; wherein the instructions comprise written instructions; wherein the instructions comprise pictorial instructions; wherein the instructions comprise video instructions; wherein the instructions comprise audio instructions; wherein the instructions comprise multimedia instructions; wherein the instructions comprise interactive instructions; wherein the instructions comprise step-by-step instructions; wherein the instructions comprise troubleshooting instructions; wherein the instructions comprise safety instructions; wherein the instructions comprise cleaning and sterilization instructions; and / or wherein the instructions comprise storage and maintenance instructions.

[0291] Detail 58: The kit of detail 52, wherein the proximal end assembly further comprises a collar, and wherein the access windows extend from the collar to the adjustable distal end assembly; wherein the collar is configured to provide a secure attachment point for the tubular retractor to a surgical table; wherein the collar is configured to provide a secure attachment point for the tubular retractor to a surgical retractor system; wherein the collar is configured to provide a secure attachment point for the tubular retractor to a robotic surgical system; wherein the collar is configured to provide a locking mechanism for the removable shims; wherein the collar is configured to provide a quick-release mechanism for the removable shims; wherein the collar is configured to provide a sealing mechanism for the access windows; wherein the collar is configured to provide a port for surgical instruments; wherein the collar is configured to provide a port for surgical implants; wherein the collar is configured to provide a port for irrigation fluids; wherein the collar is configured to provide a port for suction; and / or wherein the collar is configured to provide a port for electrical cables.

[0292] Detail 59: The kit of detail 58, wherein the collar is located at a proximal end of the tubular retractor; wherein the collar is configured to be removable from the tubular retractor; wherein the collar is configured to be replaceable with a different collar; wherein the collar is configured to be sterilizable; wherein the collar is configured to be disposable; wherein the collar is configured to be made of a radiolucent material; wherein the collar is configured to be made of a radiopaque material; wherein the collar is configured to be made of a material that is compatible with magnetic resonance imaging (MRI); wherein the collar is configured to be made of a material that is compatible with computed tomography (CT) imaging; wherein the collar is configured to be made of a material that is compatible with fluoroscopic imaging; and / or wherein the collar is configured to be made of a material that is compatible with ultrasound imaging.

[0293] Detail 60: The kit of detail 52, wherein the telescoping or extendable segments of the adjustable distal end assembly are configured to be adjusted during a minimally invasive spinal surgery to accommodate changes in surgical depth; wherein the telescoping orPCT ApplicationDocket No.: 408477-502001 WO extendable segments are configured to be adjusted in increments of 1 mm; wherein the telescoping or extendable segments are configured to be adjusted in increments of 5 mm; wherein the telescoping or extendable segments are configured to be adjusted in increments of 10 mm; wherein the telescoping or extendable segments are configured to be adjusted continuously; wherein the telescoping or extendable segments are configured to be adjusted using a manual mechanism; wherein the telescoping or extendable segments are configured to be adjusted using a powered mechanism; wherein the telescoping or extendable segments are configured to be adjusted using a remote control mechanism; wherein the telescoping or extendable segments are configured to be adjusted using a voice-activated mechanism; wherein the telescoping or extendable segments are configured to be adjusted using a foot- operated mechanism; and / or wherein the telescoping or extendable segments are configured to be automatically adjusted based on feedback from a surgical navigation system.

[0294] Detail 61 : The kit of detail 52, further comprising one or more surgical instruments configured to be inserted through the access windows to perform the minimally invasive spinal surgery; wherein the one or more surgical instruments comprise a scalpel; wherein the one or more surgical instruments comprise a dissector; wherein the one or more surgical instruments comprise a retractor; wherein the one or more surgical instruments comprise a rongeur; wherein the one or more surgical instruments comprise a curette; wherein the one or more surgical instruments comprise a probe; wherein the one or more surgical instruments comprise a nerve root retractor; wherein the one or more surgical instruments comprise a nerve hook; wherein the one or more surgical instruments comprise a pituitary forceps; wherein the one or more surgical instruments comprise a punch; wherein the one or more surgical instruments comprise a rasp; and / or wherein the one or more surgical instruments comprise a bone graft inserter.

[0295] Detail 62: The kit of detail 52, wherein the tubular retractor is configured to be mounted to a surgical table using one or more mount arms attached to the proximal end assembly; wherein the one or more mount arms are configured to be adjustable in length; wherein the one or more mount arms are configured to be adjustable in angle; wherein the one or more mount arms are configured to be lockable in a desired position; wherein the one or more mount arms are configured to be removable from the tubular retractor; wherein the one or more mount arms are configured to be sterilizable; wherein the one or more mount arms are configured to be disposable; wherein the one or more mount arms are configured to be made of a radiolucent material; wherein the one or more mount arms are configured to be made of a radiopaque material; wherein the one or more mount arms are configured to be made of a material that is compatible with magnetic resonance imaging (MRI); wherein the one or more mount arms are configured to be made of a material that is compatible with computedPCT ApplicationDocket No.: 408477-502001 WO tomography (CT) imaging; and / or wherein the one or more mount arms are configured to be made of a material that is compatible with fluoroscopic imaging.

[0296] In some embodiments, the techniques described herein relate to a modular minimally invasive tubular retractor including: a proximal end assembly including a main tube and a collar; one or more removable shims retained at the proximal end assembly and configured, when removed, to form one or more surgical access windows that extend along a length of the main tube; an adjustable distal end assembly including one or more adjustable segments configured to lengthen and / or shorten an overall length of the tubular retractor; and a distal tip at a far distal end of the adjustable distal end assembly, the distal tip having a shape selected from beveled, contoured, and cylindrical; wherein the tubular retractor is configurable to be adjusted in length prior to or during a surgery.

[0297] In some aspects, the techniques described herein relate to a tubular retractor, wherein removal of two or more removable shims forms respective first and second surgical access windows located on opposite sides of the main tube, each access window having a length of about 30-150 mm and a width of about 5-20 mm.

[0298] According to some aspects, the techniques described herein relate to a tubular retractor, further including shim locks and corresponding shim receivers at the collar configured to secure each removable shim in a closed position and to guide proximal sliding during removal.

[0299] In some embodiments, the techniques described herein relate to a tubular retractor, wherein the collar includes one or more circumferentially spaced mount interfaces configured to accept one or more mount arms to secure the tubular retractor to an operating table.

[0300] In another example, the techniques described herein relate to a tubular retractor, wherein at least a portion of a removable shim is radiolucent and the main tube is radiopaque or includes radiopaque markers to facilitate intraoperative imaging.

[0301] According to some aspects, the techniques described herein relate to a tubular retractor, wherein the adjustable distal end assembly includes telescoping segments having a manual locking mechanism selected from a threaded collar, a cam lock, and a ratchet.

[0302] In some embodiments, the techniques described herein relate to a tubular retractor, wherein the adjustable distal end assembly includes extendable segments having interlocking threads and / or snap-fit features configured to provide incremental length adjustments of about 1-10 mm per increment.

[0303] In some aspects, the techniques described herein relate to a tubular retractor, wherein the distal tip is detachable and interchangeable via a bayonet or threaded connection to provide different shapes and sizes for different anatomies.PCT ApplicationDocket No.: 408477-502001 WO

[0304] According to some aspects, the techniques described herein relate to a tubular retractor, further including a rotational coupling interface at the distal tip configured to be rotationally actuated by a mating dilator to orient the beveled shape relative to target tissue.

[0305] In some embodiments, the techniques described herein relate to a tubular retractor, wherein the distal tip includes a blind-hole configured to receive an orientation pin to provide fluoroscopic orientation confirmation.

[0306] In some aspects, the techniques described herein relate to a tubular retractor, further including radiopaque bands or fiducials disposed at predefined axial positions to indicate insertion depth under fluoroscopy.

[0307] According to some aspects, the techniques described herein relate to a tubular retractor, wherein the tubular retractor has a total length adjustable between about 50-200 mm and an inner diameter of about 10-30 mm.

[0308] In some embodiments, the techniques described herein relate to a tubular retractor, further including a proximal accessory slot configured to receive at least one visualization device aligned with a longitudinal axis of the main tube.

[0309] In another example, the techniques described herein relate to a tubular retractor, wherein the visualization device includes a camera and / or a light source positioned to illuminate a working corridor of the main tube.

[0310] In some aspects, the techniques described herein relate to a tubular retractor, wherein the accessory slot is further configured to receive at least one suction, irrigation, smokeevacuation, navigation, or sensor accessory sized to the slot profile.

[0311] In some embodiments, the techniques described herein relate to a tubular retractor, wherein a component of the tubular retractor is formed of a biocompatible material selected from stainless steel, titanium, aluminum, PEEK, PEKK, PPSLI, PSU, carbon fiber composite, and combinations thereof.

[0312] According to some aspects, the techniques described herein relate to a tubular retractor, wherein one or more components are sterilizable for reuse and at least one extension or distal tip is disposable.

[0313] In some aspects, the techniques described herein relate to a tubular retractor, wherein a mount arm coupled to the collar is adjustable in length and angle and includes a quick-lock to maintain a selected position during the surgery.

[0314] In some embodiments, the techniques described herein relate to a sliding access tubular retractor including: a hollow windowed insertion tube having a proximal end and a distal end; one or more slotted windows on a first side of the tube and (when more than one), a second slotted window on an opposite side and / or with a third slotted window on a third side; a first sliding panel configured to translate along the tube to open or close the first slotted window and a second sliding panel (optional) configured to translate along the tube to openPCT ApplicationDocket No.: 408477-502001 WO or close the second slotted window; there can also be a third sliding panel and a third sliding panel as these are non-limiting examples; and an interchangeable distal end configured to fit a targeted surgical site; wherein each sliding panel is removable in a proximal direction to fully open the corresponding slotted window.

[0315] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein each sliding panel includes opposed extensions configured to enter complementary sliding slots bordering the corresponding slotted window.

[0316] In another example, the techniques described herein relate to a sliding access tubular retractor, further including a lock for each sliding panel, the lock selected from a detent, latch, bayonet, or threaded stop to maintain a selected opening position.

[0317] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, wherein at least one slotted window extends along at least 40-90% of a longitudinal length of the tube to provide angled instrument access.

[0318] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein at least one sliding panel includes a removable seal to reduce fluid or smoke egress during insertion.

[0319] In some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the interchangeable distal end is beveled, contoured, or cylindrical and is removably attached to the distal end of the tube.

[0320] In some embodiments, the techniques described herein relate to a sliding access tubular retractor, further including angled instrument ports formed by partial withdrawal of a sliding panel to guide instruments at 10-60° relative to the tube axis.

[0321] According to some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the proximal end includes at least one mount bracket and an offset bracket to interface with a surgical table.

[0322] In some aspects, the techniques described herein relate to a sliding access tubular retractor, wherein the first and second sliding panels are independently operable to provide asymmetric access windows.

[0323] In some embodiments, the techniques described herein relate to a method of performing a minimally invasive spinal surgery, including: positioning a tubular retractor at an incision; adjusting a length of the tubular retractor by lengthening or shortening an adjustable distal end assembly; removing at least one removable shim from a proximal end assembly to form an access window; coupling a dilator to a distal tip of the tubular retractor and rotating the dilator to orient a beveled portion of the distal tip relative to target tissue; and performing a surgical step through the tubular retractor.

[0324] According to some aspects, the techniques described herein relate to a method, wherein adjusting the length includes telescoping segments that lock at 1-10 mm increments.PCT ApplicationDocket No.: 408477-502001 WO

[0325] In another example, the techniques described herein relate to a method, further including inserting in sequence a non-cannulated dilator followed by at least one cannulated dilator to dilate a tissue corridor to an inner diameter of the tubular retractor.

[0326] In some embodiments, the techniques described herein relate to a method, further including placing an orientation pin through a hole in the distal tip and confirming bevel orientation under fluoroscopy.

[0327] In some aspects, the techniques described herein relate to a method, further including coupling navigation and / or neuromonitoring to a dilator during initial tract establishment.

[0328] According to some aspects, the techniques described herein relate to a method, further including partially or fully removing an additional shim to form a second access window on a side opposite the first access window.

[0329] In some embodiments, the techniques described herein relate to a method, further including inserting a visualization device and / or a light source into a proximal accessory slot aligned with the retractor axis.

[0330] In some aspects, the techniques described herein relate to a method, further including evacuating smoke and / or irrigating through an accessory introduced via the proximal slot.

[0331] According to some aspects, the techniques described herein relate to a method, further including securing the tubular retractor to a table via a mount arm to stabilize the working corridor.

[0332] In some embodiments, the techniques described herein relate to a method, wherein rotating the dilator rotates the distal tip by engagement of a longitudinal notch of the dilator with an internal bump of the distal tip.

[0333] In another example, the techniques described herein relate to a surgical system including: the tubular retractor; a dilator set including at least a first non-cannulated dilator and a second and a third cannulated dilator sized to sequentially expand a tissue corridor; and a proximal accessory slot configured to receive visualization and adjunct accessories.

[0334] According to some aspects, the techniques described herein relate to a system, wherein the third cannulated dilator includes a longitudinal notch configured to engage an internal bump within the distal tip to transmit rotation to the distal tip.

[0335] In some embodiments, the techniques described herein relate to a system, wherein the first dilator includes a tapered working tip and a handle configured for traction and navigation coupling.

[0336] In some aspects, the techniques described herein relate to a system, wherein dilator outer diameters increase in steps of about 1-5 mm to match a desired inner diameter of the tubular retractor.

[0337] According to some aspects, the techniques described herein relate to a system, further including a fluoroscopic orientation pin sized to pass through a hole of the distal tip.PCT ApplicationDocket No.: 408477-502001 WO

[0338] In some embodiments, the techniques described herein relate to a system, wherein the accessory slot is configured to hold a camera and / or a light in alignment with a longitudinal axis of the retractor.

[0339] In some aspects, the techniques described herein relate to a system, wherein the system further includes at least one suction, irrigation, smoke-evacuation, navigation, EMG, ultrasound, or cable-management accessory adapted to the accessory slot.

[0340] According to some aspects, the techniques described herein relate to a system, further including one or more mount arms configured to couple to the collar of the tubular retractor and lock in position.

[0341] In some embodiments, the techniques described herein relate to a system, wherein at least one component of the dilator set is single-use and at least one component of the retractor is reusable.

[0342] In another example, the techniques described herein relate to a system, wherein the dilator set is packaged with the tubular retractor as a sterile kit.

[0343] According to some aspects, the techniques described herein relate to a kit for minimally invasive spinal surgery including: a plurality 1 in different inner diameters and lengths; a set of interchangeable distal tips of different shapes; and instructions for use describing intraoperative length adjustment and access-window creation.

[0344] In some embodiments, the techniques described herein relate to a kit, further including multiple removable shims of different widths to customize access-window dimensions.

[0345] In some aspects, the techniques described herein relate to a kit, wherein at least one component is color-coded by size and / or shape to assist selection during surgery.

[0346] According to some aspects, the techniques described herein relate to a kit, further including sterilization trays configured to separate reusable components from single-use components.

[0347] In some embodiments, the techniques described herein relate to a kit, wherein at least one component is MRI-compatible and radiolucent for intraoperative imaging.

[0348] In some aspects, the techniques described herein relate to a kit, further including drapes or caps adapted to the collar and accessory slot to maintain sterility around cables and optics.

[0349] In another example, the techniques described herein relate to a kit, further including a navigation marker or fiducial configured for attachment to the collar.

[0350] In some embodiments, the techniques described herein relate to a kit, wherein the interchangeable distal tips attach via a bayonet or threaded mechanism providing a tactile and / or audible lock indication.PCT ApplicationDocket No.: 408477-502001 WO

[0351] According to some aspects, the techniques described herein relate to a kit, further including user instructions for rotating the distal tip using a keyed dilator coupling and for confirming orientation by an orientation pin under fluoroscopy.

[0352] In some aspects, the techniques described herein relate to a dilator apparatus for use with a tubular retractor, including: a first non-cannulated dilator; and at least one cannulated dilator having a longitudinal notch configured to engage an internal bump of a distal tip of the tubular retractor to transmit rotation to the distal tip when the cannulated dilator is rotated.

[0353] In some embodiments, the techniques described herein relate to a dilator apparatus, further including a third cannulated dilator larger than the at least one cannulated dilator to achieve a target corridor diameter.

[0354] In some aspects, the techniques described herein relate to a dilator apparatus, wherein at least one dilator includes a handle with a textured grip and a rotation-index marker aligned with the longitudinal notch.

[0355] According to some aspects, the techniques described herein relate to a dilator apparatus, wherein at least one dilator includes a radiopaque band proximate a distal end to indicate depth under fluoroscopy.

[0356] In some embodiments, the techniques described herein relate to a dilator apparatus, wherein the non-cannulated dilator has a tapered tip configured to establish an initial tract under navigation and / or neuromonitoring.

[0357] In another example, the techniques described herein relate to a dilator apparatus, wherein the cannulated dilator has one or more fenestrations or side ports for irrigation and / or pressure relief.

[0358] In some aspects, the techniques described herein relate to a dilator apparatus, wherein the dilators are formed of stainless steel, titanium, PEEK, or combinations thereof.

[0359] In some embodiments, the techniques described herein relate to a dilator apparatus, wherein the dilators are provided in length options of about 50-200 mm and outer diameters that increase in steps of about 1-5 mm.

[0360] According to some aspects, the techniques described herein relate to a distal tip assembly for a tubular retractor, including: a rotatable beveled tip body configured to couple to an adjustable distal end assembly; an internal bump disposed on an inner surface of the beveled tip body to mate with a longitudinal notch of a dilator; and a through-hole configured to receive an orientation pin to indicate a rotational orientation under imaging.

[0361] In some aspects, the techniques described herein relate to a distal tip assembly, wherein the beveled tip body is interchangeable with a contoured or cylindrical tip body.

[0362] In some embodiments, the techniques described herein relate to a distal tip assembly, wherein the beveled tip forms an angle of about 30-60° relative to a longitudinal axis of the tubular retractor.PCT ApplicationDocket No.: 408477-502001 WO

[0363] According to some aspects, the techniques described herein relate to a distal tip assembly, wherein at least a portion of the tip body is formed of a soft, atraumatic material having a Shore A durometer of about 20-60.

[0364] In another example, the techniques described herein relate to a distal tip assembly, further including a reflective or light-guiding surface configured to direct light toward a surgical site.

[0365] In some embodiments, the techniques described herein relate to a distal tip assembly, wherein the tip body is coupled via a bayonet or threaded mechanism enabling tool-free exchange.

[0366] According to some aspects, the techniques described herein relate to a distal tip assembly, further including surface markings or flats configured to visually indicate the direction of the bevel.

[0367] According to some aspects, the techniques described herein relate to an accessoryslot module for a tubular retractor including: a longitudinal slot at a proximal region of the retractor configured to receive and retain one or more accessories aligned with a working corridor, the module including a retention mechanism selected from a spring detent, bayonet catch, and threaded clamp.

[0368] In some embodiments, the techniques described herein relate to an accessory-slot module, wherein the accessories include a camera, a light, and a combined camera-light unit.

[0369] In some aspects, the techniques described herein relate to an accessory-slot module, wherein the accessories include at least one of a suction cannula, an irrigation / suction wand, or a smoke-evacuation tube.

[0370] According to some aspects, the techniques described herein relate to an accessoryslot module, wherein the accessories include at least one of a navigation probe, EMG lead, or endoscopic imaging fiber.

[0371] In some embodiments, the techniques described herein relate to an accessory-slot module, wherein the accessories include at least one of a monopolar or bipolar cautery holder, a micro-ultrasound or Doppler probe.

[0372] In some aspects, the techniques described herein relate to an accessory-slot module, further including a cable-management clip configured to route cables along the retractor and / or a mount arm.

[0373] According to some aspects, the techniques described herein relate to a method for using a sliding access tubular retractor, including: inserting a hollow windowed insertion tube with first and second sliding panels fully closed; after insertion, retracting at least one sliding panel in a proximal direction to open a corresponding slotted window; and advancing a surgical instrument through the slotted window at an angle relative to a longitudinal axis of the tube.PCT ApplicationDocket No.: 408477-502001 WO

[0374] In some embodiments, the techniques described herein relate to a method, further including removing one sliding panel entirely to maximize side access while retaining the other panel in a partially closed position.

[0375] In another example, the techniques described herein relate to a method, wherein the first and second sliding panels are retracted to different extents to create asymmetric side access.

[0376] According to some aspects, the techniques described herein relate to a method, wherein a percentage opening of a slotted window is adjusted between about 10-100% by the position of the sliding panel and a panel lock.

[0377] In some embodiments, the techniques described herein relate to a method, further including inserting a first side tool and a second side tool through respective opposite slotted windows to triangulate access at the distal end.

[0378] In some aspects, the techniques described herein relate to a method, further including using smoke evacuation and / or irrigation accessories positioned in a proximal accessory slot during instrument manipulation.

[0379] According to some aspects, the techniques described herein relate to a method, further including confirming tube position or bevel orientation by fluoroscopy or endoscopic visualization introduced through the accessory slot.

[0380] In some embodiments, the techniques described herein relate to a method, wherein the surgical procedure includes at least one of discectomy, decompression, foraminotomy, or fusion and the sliding panels are operated to maintain a clear corridor while minimizing tissue disruption.

[0381] For the avoidance of doubt and to provide an explicit technical basis for future claim drafting in different jurisdictions, the following guidance applies to the disclosure as a whole, including all figures (e.g., FIGs. 1-21 ; any other figures, reference numbers and any sub-figures) and all elements identified by reference numerals (e.g., 100-700 series where shown). Unless technically incompatible, features described in connection with any particular embodiment or figure are expressly disclosed in combination with features of any other embodiment or figure. The skilled person, using common general knowledge, will recognize that such combinations merely reflect routine design choices within the scope of the same overall inventive concept(s). Any specific combinations called out below are illustrative and non-exhaustive, and further combinations apparent to the skilled person are also explicitly contemplated.

[0382] Reference numerals are for orientation only and do not limit the scope of the features to any particular location, orientation, material, scale, or manufacturing method. Figure numbering is likewise non-limiting: features shown in one figure may be implemented in devices or methods shown in other figures, provided functional compatibility. Labels such asPCT ApplicationDocket No.: 408477-502001 WO“first,” “second,” “third,” etc. distinguish elements and do not prescribe sequence, priority, or quantity unless expressly stated. Terms such as “about,” “approximately,” and the like encompass ±10% (or a tighter tolerance where context dictates). Ranges recited herein explicitly include all sub-ranges and individual endpoints; unless stated otherwise, endpoints of different disclosed ranges may be combined to form additional ranges with technical basis in this description.

[0383] Each optional feature is independently optional. Where two or more alternatives are disclosed (for example, a beveled, contoured, or cylindrical distal tip), each alternative is disclosed in isolation and in any technically sensible combination with other features unless a specific incompatibility is stated. Where a feature is described as being “configured to” achieve a function, the disclosure extends to any structure that objectively provides that function, without limiting the feature to an illustrative mechanism. Materials (e.g., metals, polymers, composites), dimensions (e.g., lengths, diameters, thicknesses), and manufacturing approaches (e.g., machining, molding, additive processes) described for one component are disclosed for the corresponding components in other embodiments, unless functionally incompatible.

[0384] By way of non-limiting examples of contemplated combinations that have explicit basis herein: (i) the rotating or orientable distal tip (e.g., 145 or a functional equivalent) may be used with any tubular retractor body (e.g., 110, 111 , or variants having adjustable or telescoping segments 600-series) and with any shim / window configuration (e.g., 170, 171 , 175 or sliding windows and panels such as 225, 230, 245, 250); (ii) the keyed actuation interface between a dilator and the distal tip (e.g., notch / bump features 426 / 425) may be employed with any dilator sequence (e.g., 405, 410, 415 or size-equivalent sets) and with any distal tip shape where rotational orientation is desirable; (iii) the accessory slot at the proximal region (e.g., 450) can retain visualization, illumination, suction / irrigation, smoke-evacuation, navigation, EMG, ultrasound / Doppler, endoscopic fiber, cable-management, or other function-equivalent accessories, alone or in any combination, and may be used simultaneously with the keyed bevel-orientation features; (iv) fluoroscopic orientation aids (e.g., blind-hole / pin 430 / 435, radiopaque markers or bands) are disclosed for use with any embodiment of the retractor and / or distal tip, including when sliding panels are opened asymmetrically; and (v) mount arms, brackets, and offsets (e.g., 280-290, 605-611) disclosed with one tube style are applicable to others and may be interchanged or adjusted to suit patient anatomy or operative approach.

[0385] Nothing in this specification should be read as requiring a particular order of steps unless the order is inherently necessary to achieve the recited function. Thus, where a method teaches positioning, adjusting length, forming an access window, orienting a distal tip, andPCT ApplicationDocket No.: 408477-502001 WO performing a surgical step, those actions are disclosed in any operable order or with steps omitted or added as appropriate to a given clinical scenario. Likewise, opening one or more windows and / or removing one or more shims is disclosed in any sequence and to any extent (partial or full) required to obtain the desired surgical access while preserving stability.

[0386] The disclosure also contemplates functional substitution: a component that provides substantially the same technical effect may replace a specifically illustrated component. For example, a cam or ratchet may replace a threaded collar to lock telescoping distal segments; a bayonet, snap-fit, or threaded interface may provide the removable coupling between the tube and a distal tip; and an internal keyway profile may be used in lieu of a discrete bump to transmit rotation from a dilator. Similarly, a single integrated accessory may deliver two or more functions (e.g., combined camera-light unit; irrigation-suction wand; smoke evacuation integrated with filtration) while occupying the same accessory slot profile.

[0387] In descriptions of dimensions, lengths, diameters, angles, and materials, unless a value is expressly characterized as critical, values are illustrative and can be substituted from the disclosed ranges and sub-ranges to accommodate patient size, level, approach, and surgeon preference. Any given feature described with a first set of values (e.g., length adjustable in 1-10 mm increments, inner diameter 10-30 mm, bevel angle 30-60°) is disclosed with any other compatible values disclosed for analogous features elsewhere in this specification. The skilled person will recognize that such substitutions are routine and do not change the underlying technical contribution.

[0388] To support dependent-claim drafting flexibility, each dependent feature disclosed herein is expressly disclosed as depending from any independent claim and from any intermediate dependent claim that renders the combination operable. For example, the keyed bevel-orientation interface may depend from a claim reciting a tubular retractor with a rotatable distal tip, regardless of whether the retractor body is a shim-removal type, a sliding-panel type, or an adjustable-length type; likewise, the accessory slot feature may depend from any claim directed to a tubular retractor, system, or kit, with or without specific dilator sequences. Where a claim refers to “a” or “an” element, it permits one or more of the element unless clearly limited by context.

[0389] Directional and anatomical terms (e.g., proximal / distal, superior / inferior, left / right) are used for convenience relative to the patient or instrument as oriented in the drawings and do not limit use to a particular orientation. The drawings are schematic and not to scale unless stated; relative sizes in the drawings do not limit actual dimensions. Embodiments labeled “example,” “preferred,” “optional,” or similar do not exclude other embodiments; the absence of a feature from a figure does not teach away from including that feature where technically compatible. Embodiments described as “separate” components may be formed integrally, andPCT ApplicationDocket No.: 408477-502001 WO vice versa. Components described as “rigid” may include limited elasticity or compliance as appropriate to achieve the recited function.

[0390] Importantly, the terms “comprise,” “comprising,” “include,” “including,” and the like are used in their open, non-limiting sense. In appropriate contexts, narrower versions (“consisting essentially of,” “consisting of’) are also explicitly disclosed as alternatives for national practice variations. The present disclosure is intended to provide explicit written description support for combinations of features across the embodiments shown and described, to the extent technically sensible, so that such combinations may be claimed singly or in combination without introducing added subject-matter beyond the content of this application as filed. In any interpretation of the claims appended hereto, it is noted that no claims or claim elements are intended to invoke or be interpreted under 35 ll.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.

[0391] In general, any combination of disclosed features, components and methods described herein is possible. Steps of a method can be performed in any order that is physically possible. Any numbered feature of the drawings can be present, not present, or present in a plurality.

[0392] Any and all cited references are incorporated by reference herein. Although embodiments have been disclosed, it is not desired to be limited thereby. Rather, the scope should be determined only by the appended claims.

[0393] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present disclosure, as set forth in the following claims.

[0394] The foregoing discussion of the disclosure has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the disclosure are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0395] Moreover, though the present disclosure has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and / orPCT ApplicationDocket No.: 408477-502001 WO equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and / or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

[0396] The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While specific embodiments of, and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. For example, while method steps or functions are presented in a given order, alternative embodiments may perform functions in a different order, or functions may be performed substantially concurrently. The teachings of the disclosure provided herein can be applied to other procedures or methods as appropriate. The various embodiments described herein can be combined to provide further embodiments. Aspects of the disclosure can be modified, if necessary, to employ the compositions, functions and concepts of the above references and application to provide yet further embodiments of the disclosure. Moreover, due to biological functional equivalency considerations, some changes can be made in protein structure without affecting the biological or chemical action in kind or amount. These and other changes can be made to the disclosure in light of the detailed description. All such modifications are intended to be included within the scope of the appended claims.

[0397] Specific elements of any of the foregoing embodiments can be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosure. The methods, kits, formulations, and devices disclosed herein can be combined in any way into systems to address the current needs in surgery.EXAMPLESEXAMPLE 1. PRODUCTION OF A SLIDING ACCESS TUBULAR RETRACTOR FOR MINIMALLY INVASIVE SURGERY

[0398] Traditional (prior art) tubular retractors often require multiple steps for insertion, retraction, and removal of the tube, leading to increased surgical time and potential complications. The lack of a comprehensive solution that combines the benefits of customizable access, angled instrument ports, and streamlined operation has presented challenges in achieving efficient and effective minimally invasive surgical procedures. None of the prior approaches have provided a comprehensive solution that combines the features described in this disclosure.

[0399] While producing various new retractors, the following examples are covered, wherein the technology disclosed below can be discussed by reviewing / discussing the following list ofPCT ApplicationDocket No.: 408477-502001 WO examples, which can be inter-combined with any other embodiment, aspect, or discussion point disclosed herein:

[0400] Example 1. A sliding access tubular retractor for performing minimally invasive surgery, comprising: a tubular retractor assembly including a hollow windowed insertion tube for accepting a surgical instrument, the tubular retractor assembly configured to provide access to a targeted surgical site and allow placement of the surgical instrument; sliding window panels disposed on the tubular retractor assembly, the sliding window panels configured to be inserted into tissue, retracted upwards, and removed to position the tubular retractor assembly, open access windows, and provide access to the targeted surgical site; and angled instrument ports formed by the sliding window panels, the angled instrument ports configured to place surgical instruments at an angle to access the targeted surgical site.

[0401] Example 2. The sliding access tubular retractor of example 1 , further comprising an interchangeable distal tip configured to fit with the targeted surgical site to match anatomy of the surgical site for optimal positioning, wherein the interchangeable distal tip includes anatomical fitting shapes.

[0402] Example 3. The sliding access tubular retractor of example 1 , wherein the tubular retractor assembly includes a proximal end with a mount bracket and a custom shaped distal end.

[0403] Example 4. The sliding access tubular retractor of example 1 , wherein the sliding window panels include a first sliding panel disposed in a first slotted window on one side of the tubular retractor assembly and a second sliding panel disposed in a second slotted window on an opposite side of the tubular retractor assembly.

[0404] Example 5. The sliding access tubular retractor of example 4, wherein the first sliding panel and the second sliding panel are configured to be retracted upwards to the proximal end either partially or fully to be removed from the tubular retractor assembly.

[0405] Example 6. The sliding access tubular retractor of example 4, wherein the first sliding panel and the second sliding panel are configured to open at least one of the first slotted window or the second slotted window to provide access to the targeted surgical site at the distal end.

[0406] Example 7. The sliding access tubular retractor of example 1 , wherein the angled instrument ports are configured to provide angled access to the targeted surgical site relative to a main axis of the tubular retractor assembly.

[0407] Example 8. The sliding access tubular retractor of example 1 , wherein the sliding window panels are configured to be inserted into the tissue with the tubular retractor assembly, the distal end of the tubular retractor assembly being inserted first with the sliding window panels fully slid down along a length of the tubular retractor assembly.PCT ApplicationDocket No.: 408477-502001 WO

[0408] Example 9. A method of accessing a surgical site, comprising: inserting a tubular retractor assembly into tissue, the tubular retractor assembly including sliding window panels fully slid down along a length of the tubular retractor assembly; retracting at least one of the sliding window panels upwards to open an access window in the tubular retractor assembly; placing a surgical instrument through the tubular retractor assembly and the access window to access a targeted surgical site; placing at least one surgical instrument through an angled instrument port formed by the at least one of the sliding window panels to access the targeted surgical site at an angle relative to the tubular retractor assembly; and wherein a surgeon performing a surgery can access either side of the tubular retractor via using a sliding window panel on one side of the retractor and / or on the other side of the retractor.

[0409] Example 10. The method of example 9, further comprising removing the at least one of the sliding window panels from the tubular retractor assembly to provide increased access to the targeted surgical site.

[0410] Example 11. The method of example 9, wherein retracting the at least one of the sliding window panels includes retracting the at least one of the sliding window panels to a proximal end of the tubular retractor assembly.

[0411] Example 12. The method of example 9, wherein retracting the at least one of the sliding window panels includes partially retracting the at least one of the sliding window panels.

[0412] Example 13. The method of example 9, wherein the sliding window panels include a first sliding panel in a first slotted window on one side of the tubular retractor assembly and a second sliding panel in a second slotted window on an opposite side of the tubular retractor assembly.

[0413] Example 14. The method of example 13, wherein retracting the at least one of the sliding window panels includes retracting at least one of the first sliding panel or the second sliding panel.

[0414] Example 15. The method of example 9, further comprising fitting an interchangeable distal tip to the tubular retractor assembly to match anatomy of the targeted surgical site for optimal positioning.

[0415] Example 16. The method of example 15, wherein the interchangeable distal tip includes pre-designed anatomical fitting shapes.

[0416] Example 17. The method of example 9, wherein placing the at least one surgical instrument through the angled instrument port includes accessing the targeted surgical site at the angle relative to a main axis of the tubular retractor assembly.

[0417] Example 18. The method of example 9, wherein inserting the tubular retractor assembly includes inserting the tubular retractor assembly distal end first into the tissue.

[0418] Example 19. The method of example 9, wherein the tubular retractor assembly includes a hollow windowed insertion tube for accepting the surgical instrument.PCT ApplicationDocket No.: 408477-502001 WO

[0419] Example 20. The method of example 9, wherein the tubular retractor assembly includes a proximal end with a mount bracket and a custom shaped distal end.

[0420] Example 21. A sliding access tubular retractor for performing minimally invasive surgery, comprising: a hollow windowed insertion tube capable of accepting a surgical instrument, the hollow windowed insertion tube including a proximal end and a distal end; a first slotted window on one side of the hollow windowed insertion tube; a second slotted window on an opposite side of the hollow windowed insertion tube; a first sliding panel configured to slide along a length of the hollow windowed insertion tube to open or close the first slotted window; a second sliding panel configured to slide along the length of the hollow windowed insertion tube to open or close the second slotted window; and an interchangeable custom-shaped distal end configured to fit a targeted surgical site.

[0421] Example 22. The sliding access tubular retractor of example 21 , wherein the proximal end includes a mount bracket.

[0422] Example 23. The sliding access tubular retractor of example 21 , wherein the first sliding panel and the second sliding panel are configured to be retracted upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube.

[0423] Example 24. The sliding access tubular retractor of example 21 , wherein the first sliding panel and the second sliding panel are configured to provide one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end.

[0424] Example 25. The sliding access tubular retractor of example 21 , wherein the interchangeable custom-shaped distal end is configured to be fitted with pre-designed shapes to fit the targeted surgical site.

[0425] Example 26. The sliding access tubular retractor of example 21 , wherein the hollow windowed insertion tube is capable of accepting the surgical instrument in a hollow portion of the hollow windowed insertion tube.

[0426] Example 27. A method for performing minimally invasive surgery using a sliding access tubular retractor, the method comprising: inserting the sliding access tubular retractor into a tissue of a subject, wherein the sliding access tubular retractor comprises a hollow windowed insertion tube having a proximal end, a distal end, a first slotted window on one side of the hollow windowed insertion tube, a second slotted window on an opposite side of the hollow windowed insertion tube, a first sliding panel, and a second sliding panel; sliding the first sliding panel and the second sliding panel along a length of the hollow windowed insertion tube to close the first slotted window and the second slotted window during insertion; retracting at least one of the first sliding panel or the second sliding panel along the length of the hollow windowed insertion tube to open at least one of the first slotted window or the second slotted window, thereby providing access to a targeted surgical site at the distal end; wherein aPCT ApplicationDocket No.: 408477-502001 WO surgeon performing the surgery can access either side of the sliding access tubular retractor by using either one of the first sliding panel and / or the second sliding panel; and interchangeably fitting the distal end with a custom-shaped distal end to fit the targeted surgical site.

[0427] Example 28. The method of example 27, wherein retracting at least one of the first sliding panel or the second sliding panel comprises retracting the at least one of the first sliding panel or the second sliding panel upwards to the proximal end either partially or fully to be removed from the hollow windowed insertion tube.

[0428] Example 29. The method of example 27, wherein retracting at least one of the first sliding panel or the second sliding panel provides one or more side openings to place one or more surgical instruments at an angle to access the targeted surgical site at the distal end.

[0429] Example 30. The method of example 27, wherein interchangeably fitting the distal end with the custom-shaped distal end comprises fitting the distal end with pre-designed shapes to fit the targeted surgical site.

[0430] Example 31. The method of example 27, further comprising accepting a surgical instrument in a hollow portion of the hollow windowed insertion tube.

[0431] Example 32. The method of example 27, wherein inserting the sliding access tubular retractor into the tissue of the subject comprises inserting the distal end first into the tissue.

[0432] Example 33. The method of example 27, wherein the proximal end includes a mount bracket.

[0433] Example 34. The sliding access tubular retractor of example 21 , wherein the first sliding panel and the second sliding panel are configured to slide independently of each other.

[0434] Example 35. The sliding access tubular retractor of example 21 , wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube.

[0435] Example 36. The method of example 27, wherein sliding the first sliding panel and the second sliding panel comprises sliding the first sliding panel and the second sliding panel independently of each other.

[0436] Example 37. The method of example 27, wherein the first slotted window and the second slotted window extend along a substantial portion of the length of the hollow windowed insertion tube.

[0437] Example 38. The sliding access tubular retractor of example 21 , wherein the interchangeable custom-shaped distal end is configured to be removably attached to the distal end of the hollow windowed insertion tube.

[0438] Example 39. The method of example 27, wherein interchangeably fitting the distal end with the custom-shaped distal end comprises removably attaching the custom-shaped distal end to the distal end of the hollow windowed insertion tube.PCT ApplicationDocket No.: 408477-502001 WO

[0439] Example 40. The sliding access tubular retractor of example 21 , wherein the first sliding panel and the second sliding panel are configured to be retracted in a proximal direction to open the first slotted window and the second slotted window, respectively.EXAMPLE 2. TESTING IN ACTUAL SURGERIES

[0440] In this prophetic example of representative use, various embodiments are tried and / or implemented during and / or after actual testing; and these results and / or examples are discussed below.

[0441] Manufacture & tolerances of the keyed bevel / dilator coupling: In one implementation, the internal bump 425 has a height of about 0.2-1.0 mm and a chord length of about 0.5-2.0 mm; the dilator notch 426 has a complementary width of about 0.6-2.2 mm. Diametral clearance between 425 / 426 is about 0.05-0.20 mm to provide low-friction engagement with tactile indexing. The bevel tip may be investment-cast or additively manufactured and finish- machined; edges are radiused (e.g., 0.2-0.5 mm) to maintain atraumatic flow within the lumen.

[0442] Fluoroscopic orientation aids (explicit alternatives): Orientation may be confirmed by a pin blind-hole 430 (or a pin through hole 430) and / or by one or more radiopaque bands placed at known angular offsets (e.g., 90° relative to the pin axis). Bands can be tantalum or tungsten inserts press-fit or laser-brazed into shallow grooves of the distal piece to generate clear AP / lateral signatures.

[0443] Accessory-slot interface definition (retention, travel, power): The accessory slot 450 includes a standardized rail (e.g., miniature T-slot or dovetail) with fore-aft travel of about IQ- 40 mm. Module retention is provided by a spring detent or bayonet catch furnishing a nominal holding force of about 2-10 N while permitting single-hand release. Electrical / optical connectors (where used) are keyed and strain-relieved to route proximally along the slot or mount arm without occluding the corridor.

[0444] Window mechanics & angled ports (explicit ranges): Sliding panels 645 / 650 may be opened partially (e.g., 10-90% of window length) to create angled ports whose instrument centerlines intersect the tube axis at about 10-60°. Panels can be removed entirely to maximize lateral clearance while an opposing panel remains closed to shield adjacent tissue.

[0445] Mount arms and offsets — repeatable setup: Collar 210 provides circumferential bosses at indexed “clock” positions (e.g., 30° increments). Offset brackets (e.g., 610 / 611) include engraved angular indicia (±0-45°) and detents to facilitate reproducible positioning. Telescoping arms include length scales (e.g., 5 mm graduations) to record a preferred setup for return cases.

[0446] Working angles over bone (cross-reference FIG. 20): When seated on bone (e.g., vertebral surface), the system maintains a stable central corridor while supporting ipsilateral or contralateral tasks using instrument obliquity of about 0-60° relative to the tube axis. ThisPCT ApplicationDocket No.: 408477-502001 WO angular envelope is achieved with partial window opening and / or bevel orientation without moving the collar fixation.

[0447] Kits and cross-compatibility: Kits may include the tubular retractor, dilator series (noncannulated and cannulated), interchangeable distal tips (bevel / contour / cylindrical), orientation pin, and accessory modules for the slot 450 (camera, light, suction / irrigation, smoke evacuation, navigation / EMG, endoscopic fiber, Doppler), with components sized to a common rail profile to ensure cross-compatibility.

[0448] Best-mode I exemplary mode (optional): By way of example, a 20 mm inner-diameter tube with 50-150 mm adjustable distal length, bevel angle about 30-60°, and windows extending 40-120 mm has been found to provide a balance of access, stability, and visualization for common lumbar procedures.

[0449] As further testing in real surgeries is done in the future, more options are expected. Prophetic workflow and representative use (non-limiting): In representative use, a patient is positioned according to standard clinical practice. A modular minimally invasive tubular retractor 110 is selected from a kit based on imaging and level, for example an inner diameter of about 14-24 mm and an adjustable distal length set between about 60-140 mm. The collar 210 is affixed using mount arms 280 / 285 at selected clocking positions with offsets 610 / 611 to clear drapes and allow line-of-sight to the target. Initial tract establishment is performed with a first, non-cannulated dilator 405 under navigation and / or neuromonitoring. A second cannulated dilator 410, followed by a third cannulated dilator 415, is advanced to expand tissue atraumatically to the target diameter. The surgeon may then couple the 415 notch 426 to the internal bump 425 of the distal bevel 145 and impart controlled rotation to aim the bevel lip relative to target tissue. Orientation is confirmed by a pin 435 through hole 430 (or blind hole 430) and / or by radiopaque bands, recognizing that either or both aids may be used as desired and that other orientation indicators with equivalent function can be substituted.

[0450] Windows, visualization, and angled ports (see FIG. 20 conceptually): To reach target tissue 855 over bone 850 without relocating the tube, one or both sliding panels 645 / 650 are retracted to open windows 625 / 630 to a selected percentage of length (for example, 20-80%). First and second side tools 300 / 400 are then introduced at oblique angles within a working envelope of about 0-60° relative to the tube axis (envelope 800), enabling triangulation. The proximal accessory slot 450 may hold a camera 455 and / or a light 460 to maintain visualization; if desired, suction, irrigation, and smoke-evacuation modules can be positioned along the same rail and adjusted fore-aft within about 10-40 mm of travel to avoid instrument collisions. Cables and lines are routed along the slot profile or an arm to preserve a clear operative area. Where asymmetric access is beneficial, one panel is fully removed while the opposite panel remains partially closed to shield adjacent tissue.PCT ApplicationDocket No.: 408477-502001 WO

[0451] Interchange and alternatives within the same example: Depending on anatomy, the surgeon may exchange the distal tip (beveled / contoured / cylindrical) via bayonet or threaded coupling, or adjust the distal assembly length in 1-10 mm increments to tune reach. The keyed torque-transfer interface (425 / 426) can be employed with any of these tips where rotation is advantageous; conversely, when a cylindrical or contour tip is selected and rotation is unnecessary, the keyed engagement can be disengaged and the bevel allowed to free-float. Materials for tip and tube components may be selected from stainless steel, titanium, PEEK, PEKK, PPSLI, PSU, carbon-fiber composite, and equivalents compatible with sterilization and imaging, recognizing that radiopaque markers may be integrated as bands, plugs, or surface coatings as appropriate.

[0452] Representative task sequence (illustrative only): Without limitation, the following sequence is suitable for a decompression or discectomy. After docking and dilation, the bevel 145 is oriented to retract soft tissue away from the neural element. A burr or Kerrison is introduced through a partially opened window to remove obstructing bone within the 0-60° angular envelope. Intermittent suction clears plume and fluid; illumination and / or camera provide continuous view. The pin 435 may be briefly inserted to verify bevel azimuth under fluoroscopy before an implant trial or cage insertion. If contralateral access is desired, the windows are rebalanced (e.g., 30% on one side, 60% on the other) and the bevel is reoriented by a modest twist of the 415 dilator engaged with the bump 425. At completion, panels are closed, the pin is removed if present, accessories are undocked, and the retractor is withdrawn along the dilated corridor.

[0453] Ergonomics and repeatability: The arm / bracket setup is recorded using length scales (e.g., 5 mm graduations) and angular indicia (±0-45°) on offsets 610 / 611 so that a preferred geometry can be reproduced in subsequent cases. The collar bosses at 30° increments facilitate symmetric or asymmetric arm placement, and a universal joint near the collar allows small adjustments without moving the tube foot-print. Handles on dilators include textured grips and rotation-index markers referenced to the notch 426 so rotation can be metered in small, repeatable increments.

[0454] Performance expectations and variations: While clinical outcomes depend on patient factors and surgeon technique, the configuration described here is expected to facilitate shorter setup times, reduced soft-tissue disruption, and clearer visualization by consolidating access, orientation, and adjunct functions within a single corridor. Alternatives within the disclosed ranges are contemplated: different inner diameters (e.g., 10-30 mm), alternative bevel angles (e.g., 30-60°), and different window lengths (e.g., 40-120 mm). Sliding-panel locks may be detent, threaded, or bayonet; accessory retention may be spring detent, bayonet, or threaded clamp. The notch-and-bump coupling may be replaced by a key / keyway orPCT Application Docket No.: 408477-502001 WO spline-like interface achieving substantially the same function. The prophetic nature of this example is emphasized: steps may occur in alternative orders, components may be omitted or substituted where clinically sensible, and the described values are representative rather than limiting.

[0455] Kits and logistics: In a typical kit, the tubular retractor, three-dilator set (405 / 410 / 415), interchangeable tips, orientation pin, and accessory modules are sterile-packaged with a common rail profile for the slot 450. Instructions for use describe intraoperative length adjustment, panel operation, keyed orientation, and optional imaging confirmation. In reusable embodiments, cleaning and sterilization follow hospital SOPs appropriate to the selected materials; single-use options are provided where desired. The modular architecture supports component-level replacement and upgrades without altering the overall workflow described above.

[0456] As further testing in real surgeries is done in the future, more options are expected.REFERENCES:1IIIPAC. International Union of Pure and Applied Chemistry GoldBook. https: / / goldbook.iupac.org / .2Merriam-Webster's Online Dictionary, https: / / www.merriam-webster.com / .3Porter R. S., & Kaplan, J. L. (Eds.). The Merck manual of diagnosis and therapy (19th ed.).Merck Sharp & Dohme Corp.. 2011 , (978-0-911910-19-3).4Robert S. Porter et al., (eds.). The Encyclopedia of Molecular Cell Biology and MolecularMedicine. Blackwell Science Ltd.; 1999-2012, (9783527600908).5Robert A. Meyers (ed.). Molecular Biology and Biotechnology: A Comprehensive DeskReference. VCH Publishers, Inc.; 1995, (1-56081-569-8).6Luttmann Werner. Immunology. Elsevier; 2006,7Kenneth Murphy Allan Mowat, Casey Weaver (eds.). Janeway's Immunobiology. Taylor &Francis Limited; 2014, (9780815345305).8Krebs Jocelyn E., et al. Lewin's genes XI. 11th ed. Burlington, Mass.: Jones & BartlettLearning; 2014, (1449659055).9Green Michael R. Molecular cloning : a laboratory manual / Michael R. Green, JosephSambrook. Cold Spring Harbor, N.Y: Cold Spring Harbor Laboratory Press; 2012, (1936113414).10Davis et al. Basic Methods in Molecular Biology. Elsevier Science Publishing, Inc.; 2012,(044460149X).11Jon Lorsch (ed.). Laboratory Methods in Enzymology: DNA. Elsevier; 2013,(0124199542).12Frederick M. Ausubel (ed.). Current Protocols in Molecular Biology (CPMB). John Wiley and Sons 2014, (9780471503385).13John E. Coligan (ed.). Current Protocols in Protein Science (CPPS). John Wiley andSons, Inc.; 2005,14John E. Coligan ADA M Kruisbeek, David H Margulies, Ethan M Shevach, Warren Strobe,(eds.) Current Protocols in Immunology (CPI). John Wiley and Sons, Inc.; 2003, (9780471142737).PCT ApplicationDocket No.: 408477-502001 WO

[0457] The foregoing written specification and figures are considered to be sufficient to enable one skilled in the art to practice the present aspects and embodiments. The present aspects and embodiments are not to be limited in scope by examples provided, since the examples are intended as a single illustration of one aspect and other functionally equivalent embodiments are within the scope of the disclosure. Various modifications in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims. The advantages and objects described herein are not necessarily encompassed by each embodiment. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

PCT ApplicationDocket No.: 408477-502001 WOCLAIMSWe claim:

1. A modular minimally invasive tubular retractor comprising: a proximal end assembly including a main tube and a collar; one or more removable shims retained at the proximal end assembly and configured, when removed, to form one or more surgical access windows that extend along a length of the main tube; an adjustable distal end assembly including one or more adjustable segments configured to lengthen and / or shorten an overall length of the tubular retractor; and a distal tip at a far distal end of the adjustable distal end assembly, the distal tip having a shape selected from beveled, contoured, and cylindrical; wherein the tubular retractor is configurable to be adjusted in length prior to or during a surgery.

2. The tubular retractor of claim 1, wherein removal of two or more removable shims forms respective first and second surgical access windows located on opposite sides of the main tube, each access window having a length of about 30-150 mm and a width of about 5-20 mm.

3. The tubular retractor of claim 1, further comprising shim locks and corresponding shim receivers at the collar configured to secure each removable shim in a closed position and to guide proximal sliding during removal.

4. The tubular retractor of claim 1, wherein the collar includes one or more circumferentially spaced mount interfaces configured to accept one or more mount arms to secure the tubular retractor to an operating table.

5. The tubular retractor of claim 1, wherein at least a portion of a removable shim is radiolucent and the main tube is radiopaque or includes radiopaque markers to facilitate intraoperative imaging.

6. The tubular retractor of claim 1, wherein the adjustable distal end assembly comprises telescoping segments having a manual locking mechanism selected from a threaded collar, a cam lock, and a ratchet.

7. The tubular retractor of claim 1, wherein the adjustable distal end assembly comprises extendable segments having interlocking threads and / or snap-fit features configured to provide incremental length adjustments of about 1-10 mm per increment.PCT ApplicationDocket No.: 408477-502001 WO8. The tubular retractor of claim 1, wherein the distal tip is detachable and interchangeable via a bayonet or threaded connection to provide different shapes and sizes for different anatomies.

9. The tubular retractor of claim 1, further comprising a rotational coupling interface at the distal tip configured to be rotationally actuated by a mating dilator to orient the beveled shape relative to target tissue.

10. The tubular retractor of claim 9, wherein the distal tip includes a blind-hole configured to receive an orientation pin to provide fluoroscopic orientation confirmation.

11. The tubular retractor of claim 1 , further comprising radiopaque bands or fiducials disposed at predefined axial positions to indicate insertion depth under fluoroscopy.

12. The tubular retractor of claim 1 , wherein the tubular retractor has a total length adjustable between about 50-200 mm and an inner diameter of about 10-30 mm.

13. The tubular retractor of claim 1 , further comprising a proximal accessory slot configured to receive at least one visualization device aligned with a longitudinal axis of the main tube.

14. The tubular retractor of claim 13, wherein the visualization device comprises a camera and / or a light source positioned to illuminate a working corridor of the main tube.

15. The tubular retractor of claim 13, wherein the accessory slot is further configured to receive at least one suction, irrigation, smoke-evacuation, navigation, or sensor accessory sized to the slot profile.

16. The tubular retractor of claim 1 , wherein a component of the tubular retractor is formed of a biocompatible material selected from stainless steel, titanium, aluminum, PEEK, PEKK, PPSLI, PSU, carbon fiber composite, and combinations thereof.

17. The tubular retractor of claim 1 , wherein one or more components are sterilizable for reuse and at least one extension or distal tip is disposable.PCT ApplicationDocket No.: 408477-502001 WO18. The tubular retractor of claim 1 , wherein a mount arm coupled to the collar is adjustable in length and angle and includes a quick-lock to maintain a selected position during the surgery.

19. A sliding access tubular retractor comprising: a hollow windowed insertion tube having a proximal end and a distal end; at least one slotted window on a first side of the tube and an optional second slotted window on an opposite side such as if there is more than one; a first sliding panel configured to translate along the tube to open or close the first slotted window and an optional second sliding panel configured to translate along the tube to open or close the second slotted window; and an interchangeable distal end configured to fit a targeted surgical site; wherein each sliding panel is removable in a proximal direction to fully open the corresponding slotted window.

20. The sliding access tubular retractor of claim 19, wherein each sliding panel includes opposed extensions configured to enter complementary sliding slots bordering the corresponding slotted window.

21. The sliding access tubular retractor of claim 19, further comprising a lock for each sliding panel, the lock selected from a detent, latch, bayonet, or threaded stop to maintain a selected opening position.

22. The sliding access tubular retractor of claim 19, wherein at least one slotted window extends along at least 40-90% of a longitudinal length of the tube to provide angled instrument access.

23. The sliding access tubular retractor of claim 19, wherein at least one sliding panel includes a removable seal to reduce fluid or smoke egress during insertion.

24. The sliding access tubular retractor of claim 19, wherein the interchangeable distal end is beveled, contoured, or cylindrical and is removably attached to the distal end of the tube.

25. The sliding access tubular retractor of claim 19, further comprising angled instrument ports formed by partial withdrawal of a sliding panel to guide instruments at 10-60° relative to the tube axis.

26. The sliding access tubular retractor of claim 19, wherein the proximal end includes at least one mount bracket and an offset bracket to interface with a surgical table.PCT ApplicationDocket No.: 408477-502001 WO27. The sliding access tubular retractor of claim 19, wherein the first and second sliding panels are independently operable to provide asymmetric access windows.

28. A method of performing a minimally invasive spinal surgery, comprising: positioning a tubular retractor at an incision; adjusting a length of the tubular retractor by lengthening or shortening an adjustable distal end assembly; removing at least one removable shim from a proximal end assembly to form an access window; coupling a dilator to a distal tip of the tubular retractor and rotating the dilator to orient a beveled portion of the distal tip relative to target tissue; and performing a surgical step through the tubular retractor.

29. The method of claim 28, wherein adjusting the length comprises telescoping segments that lock at 1-10 mm increments.

30. The method of claim 28, further comprising inserting in sequence a non-cannulated dilator followed by at least one cannulated dilator to dilate a tissue corridor to an inner diameter of the tubular retractor.

31. The method of claim 28, further comprising placing an orientation pin through a hole in the distal tip and confirming bevel orientation under fluoroscopy.

32. The method of claim 28, further comprising coupling navigation and / or neuromonitoring to a dilator during initial tract establishment.

33. The method of claim 28, further comprising partially or fully removing an additional shim to form a second access window on a side opposite the first access window.

34. The method of claim 28, further comprising inserting a visualization device and / or a light source into a proximal accessory slot aligned with the retractor axis.

35. The method of claim 28, further comprising evacuating smoke and / or irrigating through an accessory introduced via the proximal slot.

36. The method of claim 28, further comprising securing the tubular retractor to a table via a mount arm to stabilize the working corridor.PCT ApplicationDocket No.: 408477-502001 WO37. The method of claim 28, wherein rotating the dilator rotates the distal tip by engagement of a longitudinal notch of the dilator with an internal bump of the distal tip.

38. A surgical system comprising: the tubular retractor of claim 1; a dilator set including at least a first non-cannulated dilator and a second and a third cannulated dilator sized to sequentially expand a tissue corridor; and a proximal accessory slot configured to receive visualization and adjunct accessories.

39. The system of claim 38, wherein the third cannulated dilator comprises a longitudinal notch configured to engage an internal bump within the distal tip to transmit rotation to the distal tip.

40. The system of claim 38, wherein the first dilator includes a tapered working tip and a handle configured for traction and navigation coupling.

41. The system of claim 38, wherein dilator outer diameters increase in steps of about 1-5 mm to match a desired inner diameter of the tubular retractor.

42. The system of claim 38, further comprising a fluoroscopic orientation pin sized to pass through a hole of the distal tip.

43. The system of claim 38, wherein the accessory slot is configured to hold a camera and / or a light in alignment with a longitudinal axis of the retractor.

44. The system of claim 38, wherein the system further comprises at least one suction, irrigation, smoke-evacuation, navigation, EMG, ultrasound, or cable-management accessory adapted to the accessory slot.

45. The system of claim 38, further comprising one or more mount arms configured to couple to the collar of the tubular retractor and lock in position.

46. The system of claim 38, wherein at least one component of the dilator set is single-use and at least one component of the retractor is reusable.

47. The system of claim 38, wherein the dilator set is packaged with the tubular retractor as a sterile kit.PCT ApplicationDocket No.: 408477-502001 WO48. A kit for minimally invasive spinal surgery comprising: a plurality of tubular retractors according to claim 1 in different inner diameters and lengths; a set of interchangeable distal tips of different shapes; and instructions for use describing intraoperative length adjustment and access-window creation.

49. The kit of claim 48, further comprising multiple removable shims of different widths to customize access-window dimensions.

50. The kit of claim 48, wherein at least one component is color-coded by size and / or shape to assist selection during surgery.

51. The kit of claim 48, further comprising sterilization trays configured to separate reusable components from single-use components.

52. The kit of claim 48, wherein at least one component is MRI-compatible and radiolucent for intraoperative imaging.

53. The kit of claim 48, further comprising drapes or caps adapted to the collar and accessory slot to maintain sterility around cables and optics.

54. The kit of claim 48, further comprising a navigation marker or fiducial configured for attachment to the collar.

55. The kit of claim 48, wherein the interchangeable distal tips attach via a bayonet or threaded mechanism providing a tactile and / or audible lock indication.

56. The kit of claim 48, further comprising user instructions for rotating the distal tip using a keyed dilator coupling and for confirming orientation by an orientation pin under fluoroscopy.

57. A dilator apparatus for use with a tubular retractor, comprising: a first non-cannulated dilator; and at least one cannulated dilator having a longitudinal notch configured to engage an internal bump of a distal tip of the tubular retractor to transmit rotation to the distal tip when the cannulated dilator is rotated.

58. The dilator apparatus of claim 57, further comprising a third cannulated dilator larger than the at least one cannulated dilator to achieve a target corridor diameter.PCT ApplicationDocket No.: 408477-502001 WO59. The dilator apparatus of claim 57, wherein at least one dilator includes a handle with a textured grip and a rotation-index marker aligned with the longitudinal notch.

60. The dilator apparatus of claim 57, wherein at least one dilator includes a radiopaque band proximate a distal end to indicate depth under fluoroscopy.

61. The dilator apparatus of claim 57, wherein the non-cannulated dilator has a tapered tip configured to establish an initial tract under navigation and / or neuromonitoring.

62. The dilator apparatus of claim 57, wherein the cannulated dilator has one or more fenestrations or side ports for irrigation and / or pressure relief.

63. The dilator apparatus of claim 57, wherein the dilators are formed of stainless steel, titanium, PEEK, or combinations thereof.

64. The dilator apparatus of claim 57, wherein the dilators are provided in length options of about 50-200 mm and outer diameters that increase in steps of about 1-5 mm.

65. A distal tip assembly for a tubular retractor, comprising: a rotatable beveled tip body configured to couple to an adjustable distal end assembly; an internal bump disposed on an inner surface of the beveled tip body to mate with a longitudinal notch of a dilator; and a through-hole configured to receive an orientation pin to indicate a rotational orientation under imaging.

66. The distal tip assembly of claim 65, wherein the beveled tip body is interchangeable with a contoured or cylindrical tip body.

67. The distal tip assembly of claim 65, wherein the beveled tip forms an angle of about 30- 60° relative to a longitudinal axis of the tubular retractor.

68. The distal tip assembly of claim 65, wherein at least a portion of the tip body is formed of a soft, atraumatic material having a Shore A durometer of about 20-60.

69. The distal tip assembly of claim 65, further comprising a reflective or light-guiding surface configured to direct light toward a surgical site.PCT ApplicationDocket No.: 408477-502001 WO70. The distal tip assembly of claim 65, wherein the tip body is coupled via a bayonet or threaded mechanism enabling tool-free exchange.

71. The distal tip assembly of claim 65, further comprising surface markings or flats configured to visually indicate the direction of the bevel.

72. An accessory-slot module for a tubular retractor comprising: a longitudinal slot at a proximal region of the retractor configured to receive and retain one or more accessories aligned with a working corridor, the module including a retention mechanism selected from a spring detent, bayonet catch, and threaded clamp.

73. The accessory-slot module of claim 72, wherein the accessories include a camera, a light, and a combined camera-light unit.

74. The accessory-slot module of claim 72, wherein the accessories include at least one of a suction cannula, an irrigation / suction wand, or a smoke-evacuation tube.

75. The accessory-slot module of claim 72, wherein the accessories include at least one of a navigation probe, EMG lead, or endoscopic imaging fiber.

76. The accessory-slot module of claim 72, wherein the accessories include at least one of a monopolar or bipolar cautery holder, a micro-ultrasound or Doppler probe.

77. The accessory-slot module of claim 72, further comprising a cable-management clip configured to route cables along the retractor and / or a mount arm.

78. A method for using a sliding access tubular retractor, comprising: inserting a hollow windowed insertion tube with first and second sliding panels fully closed; after insertion, retracting at least one sliding panel in a proximal direction to open a corresponding slotted window; and advancing a surgical instrument through the slotted window at an angle relative to a longitudinal axis of the tube.

79. The method of claim 78, further comprising removing one sliding panel entirely to maximize side access while retaining the other panel in a partially closed position.PCT ApplicationDocket No.: 408477-502001 WO80. The method of claim 78, wherein the first and second sliding panels are retracted to different extents to create asymmetric side access.

81. The method of claim 78, wherein a percentage opening of a slotted window is adjusted between about 10-100% by the position of the sliding panel and a panel lock.

82. The method of claim 78, further comprising inserting a first side tool and a second side tool through respective opposite slotted windows to triangulate access at the distal end.

83. The method of claim 78, further comprising using smoke evacuation and / or irrigation accessories positioned in a proximal accessory slot during instrument manipulation.

84. The method of claim 78, further comprising confirming tube position or bevel orientation by fluoroscopy or endoscopic visualization introduced through the accessory slot.

85. The method of claim 78, wherein the surgical procedure comprises at least one of discectomy, decompression, foraminotomy, or fusion and the sliding panels are operated to maintain a clear corridor while minimizing tissue disruption.

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