Biological tissue location and marking

Abstract

Methods and related apparatus for performing surgical procedures are disclosed. Exemplary methods may include: locating a first location on a first surface of biological tissue; locating a second location on a second, opposing surface of the biological tissue, the second location corresponding to the first location; and marking the second location on the second surface. The second surface may be substantially opposite the first surface. Exemplary methods may include, after marking the second location, performing a treatment procedure on the biological tissue adjacent to the second location.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 845,313, filed May 8, 2019, which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to medical instruments and devices and related methods, and more particularly, to surgical devices and related methods for locating and / or marking locations on biological tissue (eg, the wall of a heart).

[0004] The present disclosure contemplates that some cardiac surgeries may be performed substantially entirely from within the chambers of the heart, such as by a cardiac electrophysiologist using a catheter-based procedure. The present disclosure contemplates that other cardiac surgeries may be performed substantially entirely from outside the heart, such as by a cardiac surgeon accessing the heart through a percutaneous incision. The present disclosure contemplates hybrid cardiac surgeries that may combine interventional aspects (e.g., a percutaneous endocardial approach guided by fluoroscopy) with surgical aspects (e.g., a percutaneous epicardial approach guided by direct visualization or an endoscopic camera).

[0005] The present disclosure contemplates the use of surgical pens to mark a patient's skin; however, surgical pens are generally not optimized for internal use during surgical procedures. For example, the ink used in surgical pens may be rubbed or brushed off internal structures during surgery. Furthermore, surgical pens are generally not configured for use during minimally invasive procedures. For example, surgical pens are typically not of appropriate size for insertion into a surgical site via a thoracoscopic trocar. Summary of the Invention

[0006] One aspect of the present disclosure is to provide a method for performing a surgical procedure, the method comprising locating a first location on a first surface of biological tissue; locating a second location on a second surface of the biological tissue, the second location corresponding to the first location; and / or marking the second location on the second surface.

[0007] In a more detailed embodiment, locating the second position on the second surface may include electrically locating the second position on the second surface. Electrically locating the second position on the second surface may include transmitting an electromagnetic signal through an instrument on the second surface, the instrument on the second surface including a sensor configured to detect a change in signal amplitude affected by the instrument on the first surface. Electrically locating the second position on the second surface may include measuring a closed-loop impedance between the instrument on the second surface and an opposing instrument on the first surface. Locating the second position on the second surface may include visually locating the second position on the second surface. Locating the second position on the second surface may include mechanically locating the second position on the second surface. Locating the second position on the second surface may include magnetically locating the second position on the second surface.

[0008] In a more detailed embodiment, the second surface may be substantially opposite the first surface. The method may include, after marking the second location, performing a therapeutic procedure on biological tissue near the second location. Performing the therapeutic procedure may include ablating a portion of the biological tissue. Marking the second location may include marking a point on the second surface. Marking the second location may include marking a line on the second surface. Marking the second location may include marking an area on the second surface. Marking the area may include marking a perimeter of the area. Marking the area may include marking substantially all of the interior area defined by the perimeter. Marking the second location may include placing a marker on the second surface. The marker may include a marking substance. The marking substance may include at least one of ink and a dye. The marking substance may include a radionuclide. The marking substance may include a radiopaque substance. The marking substance may include a magnetic substance. The marker may include an object. The object may include a magnetic substance. The object may be electrically insulating, and / or the method may include applying RF energy to the tissue while shielding at least a portion of the tissue from the RF energy by the marker. The object may be bioabsorbable. Placing the marker on the second surface may include at least partially penetrating the second surface. Locating the second location may be performed without piercing a biological structure. Marking the second location may include heating the tissue to form a lesion detectable on the second surface. Heating the tissue may include applying RF energy, microwave energy, and / or laser energy. The method may include visually detecting the lesion on the second surface. The method may include electrically detecting the lesion on at least one of the first surface and the second surface. Marking the second location may include applying freezing to the tissue to form ice detectable on the second surface. Applying freezing to the tissue may include applying freezing to the first surface and / or the second surface. The method may include visually detecting at least one of a lesion and ice on the second surface. The method may include mechanically detecting the ice on the second surface. Locating the second location may include expanding the biological tissue by pushing on the first surface to form a protrusion on the second surface.

[0009] In a more detailed embodiment, the biological tissue may include a heart wall, the first surface may include an endocardial surface, and / or the second surface may include an epicardial surface. Locating the first location may include locating the sinoatrial node, the atrioventricular node, a ganglionic plexus, and / or an arrhythmia region.

[0010] In a more detailed embodiment, the biological tissue may include a heart wall, the first surface may include an epicardial surface, and / or the second surface may include an endocardial surface. Locating the first location may include locating the sinoatrial node, the atrioventricular node, a ganglionic plexus, and / or an arrhythmia region.

[0011] In more detailed embodiments, locating the first position on the first surface of the biological tissue may include electroanatomical mapping.

[0012] One aspect of the present disclosure is to provide a method of marking biological tissue, the method comprising: introducing a marking device into a surgical space, the marking device comprising a slender shaft and an at least partially covered distally disposed absorbent tip; exposing the tip; and / or marking the tissue by applying a marking substance to the tissue from the tip.

[0013] In more detailed embodiments, the marking substance may include at least one of an ink, a dye, a radionuclide, a radiopaque substance, and a magnetic substance. The method may include loading the tip with a liquid prior to introducing the marking device into the surgical space. The liquid may include the marking substance. The tip may be pre-loaded with the marking substance in dry form; and / or loading the tip with the liquid may include hydrating the tip and the marking substance. The tip may include at least one microneedle, and / or marking the tissue may include piercing the tissue with the microneedle. The marking device may include a sheath slidably disposed on the shaft, the sheath being longitudinally movable between an extended configuration and a retracted configuration, and / or exposing the tip may include withdrawing the sheath from the extended configuration to the retracted configuration. The sheath may be substantially transparent, and / or the method may include aligning a distal portion of the sheath with the portion of the tissue by viewing at least a portion of the tissue through the sheath prior to exposing the tip. The tip may be longitudinally movable between an extended configuration and a retracted configuration, and / or exposing the tip may include extending the tip from the retracted configuration to the extended configuration. The method may include reloading the tip with the marking substance by moving the tip from the extended configuration to the retracted configuration.

[0014] In a more detailed embodiment, the method may include, after introducing the marking device into the surgical space, using magnetic attraction, magnetic repulsion, and / or impedance measurement of the tissue to guide the tip to a desired position. The method may include stabilizing the marking device prior to marking the tissue. Stabilizing the marking device may include stabilizing the marking device using suction and / or stabilizing the marking device using magnetic attraction.

[0015] One aspect of the present disclosure is to provide a method of marking biological tissue, the method comprising: locating a location on the biological tissue; applying a patch at the location; and / or transferring a marking substance from the patch to the tissue.

[0016] In more detailed embodiments, the marking substance may include at least one of an ink and a dye. The marking substance may include a radionuclide. The marking substance may include a radiopaque substance. The marking substance may include a magnetic substance. The patch may include a substrate configured to retain the marking substance. The substrate may be composed of a bioresorbable material, and / or the method may include leaving the patch in place on the tissue after the surgical procedure. The substrate may be composed of a biocompatible material, and / or the method may include removing the patch from the tissue before the surgical procedure is completed. The substrate may be composed of a biocompatible material, and / or the method may include leaving the patch in place on the tissue after the surgical procedure. The method may include providing the patch in a dry state. The method may include applying the patch in the dry state. The method may include hydrating the patch before applying the patch. The patch may include the substrate and the marking substance in dry form, and / or hydrating the patch may include hydrating the marking substance. Hydrating the patch may include hydrating the patch with the marking substance in liquid form.

[0017] One aspect of the present disclosure is to provide a surgical device for marking biological tissue, the surgical device comprising: an elongated shaft; a distal tip disposed on the elongated shaft, the tip comprising an absorbent material; and / or a sheath slidably disposed on the shaft, the sheath being longitudinally movable between an extended configuration and a retracted configuration. In the extended configuration, the sheath at least partially covers a distal portion of the shaft and the tip. In the retracted configuration, at least a portion of the tip is exposed.

[0018] In more detailed embodiments, at least a portion of the sheath may be substantially transparent. The tip may include at least one microneedle configured to penetrate target tissue. The tip may be configured to be loaded with a marking substance. The tip may be loaded with the marking substance. The marking substance may include at least one of an ink and a dye. The marking substance may include a radionuclide. The marking substance may include a radiopaque substance. The marking substance may include a magnetic substance. The marking substance may be a liquid. The marking substance may be in a dry state, and / or the tip and the marking substance may be configured to be hydrated prior to use.

[0019] One aspect of the present disclosure is a surgical device for marking biological tissue, the surgical device comprising an elongated shaft having a distally disposed tip comprising an absorbent material. The tip is longitudinally movable between a retracted configuration and an extended configuration. In the retracted configuration, the tip is substantially disposed within the shaft. In the extended configuration, at least a portion of the tip is exposed.

[0020] In more detailed embodiments, the tip may be configured to be loaded with a marking substance. The tip may be loaded with the marking substance. The marking substance may include at least one of an ink and a dye. The marking substance may include a radionuclide. The marking substance may include a radiopaque substance. The marking substance may include a magnetic substance. The marking substance may be a liquid. The marking substance may be in a dry state, and / or the tip and the marking substance may be configured to be hydrated prior to use.

[0021] One aspect of the present disclosure is to provide a patch for marking biological tissue, the patch comprising a substrate and / or a marking substance loaded in the substrate.

[0022] In a more detailed embodiment, the substrate may be configured to transfer at least some of the marking substance to biological tissue. The marking substance may include at least one of an ink and a dye. The marking substance may include a radionuclide. The marking substance may include a radiopaque substance. The marking substance may include a magnetic substance. The substrate may be composed of a bioabsorbable material. The substrate may be composed of a biocompatible material. The patch may include a dry form of the substrate and a dry form of the marking substance. The patch may be configured to be placed on biological tissue without prior hydration. The patch may be configured to be hydrated prior to placement on biological tissue. The marking substance may include a liquid. The substrate may include a membrane. The substrate may be electrically insulating.

[0023] One aspect of the present disclosure is to provide a method for manufacturing a biological tissue marking device, the method comprising: providing a substrate comprising at least one of a bioabsorbable material and a biocompatible material; and / or loading a marking substance into the substrate.

[0024] In a more detailed embodiment, absorbing the marker substance into the substrate may include absorbing a liquid marker substance into the substrate. The method may include dehydrating the substrate and the marker substance after loading the liquid marker substance into the substrate. The method may include hydrating the substrate and the marker substance prior to use. Loading the marker substance into the substrate may include loading the marker substance into the substrate in a dry form. The substrate may include a membrane and / or providing the substrate may include forming the membrane.

[0025] In a more detailed embodiment, providing the substrate may include providing the substrate in a ready-to-use size and shape. Providing the substrate may include providing the substrate in a size larger than a desired size and shape for use. The method may include cutting the substrate into the desired size and shape for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Exemplary embodiments are described with reference to the accompanying drawings, in which:

[0027] Figure 1 is a partial cross-sectional view of the heart showing the approximate location of the sinoatrial node;

[0028] Figure 2-7 It is a detailed cross-sectional view of the heart wall near the sinoatrial node;

[0029] Figure 8 is a cross-sectional view of an exemplary sheathed Kittner dissector (or blunt-tip dissecting tool, kittner) with the sheath in an extended configuration;

[0030] Figure 9 is a cross-sectional view of the sheathed Kittner dissector with the sheath in a retracted configuration;

[0031] Figure 10 and Figure 11 is a cross-sectional view illustrating an exemplary method of marking the epicardium using a sheathed Kittner dissector;

[0032] Figure 12 is a side view of an exemplary marking instrument in a retracted configuration;

[0033] Figure 13 is a side view of the marking instrument in an extended configuration;

[0034] Figure 14 and Figure 15 is a partial cross-sectional view illustrating an exemplary method of marking the epicardium using a marking instrument;

[0035] Figure 16 is an isometric view of an exemplary patch;

[0036] Figure 17 is a partial cross-sectional view illustrating an exemplary method of applying a patch;

[0037] Figure 18 is a detailed cross-sectional view of a heart wall showing an RF ablation device forming a marker comprising a lesion on a second (epicardial) surface;

[0038] Figure 19is a detailed cross-sectional view of a heart wall showing a cryosurgical device forming a marker including ice visible on a second (epicardial) surface; and

[0039] Figure 20 is an isometric view of biological tissue having exemplary markers thereon; these exemplary markers are all in accordance with at least some aspects of the present disclosure. DETAILED DESCRIPTION

[0040] Exemplary embodiments according to the present disclosure are described and illustrated below to cover devices, methods, and techniques related to medical and surgical procedures. Of course, it will be apparent to those of ordinary skill in the art that the embodiments discussed below are examples and may be reconstructed without departing from the scope and spirit of the present disclosure. It will also be understood that variations of the exemplary embodiments contemplated by those of ordinary skill in the art will also constitute a part of the present disclosure. However, for the sake of clarity and precision, the exemplary embodiments discussed below may include optional steps, methods, and features, which should not be considered by those of ordinary skill in the art to be constituent elements falling within the scope of the present disclosure.

[0041] The present disclosure contemplates that some surgical procedures may involve biological tissue that is accessible from both a first side and from a generally opposite second side. For example, during some hybrid cardiac procedures, both the inner surface of the heart wall (e.g., the endocardium) and the outer surface of the heart wall (e.g., the epicardium) may be accessible. During some procedures, it may be advantageous to locate a particular location on tissue from a first side and perform a therapeutic procedure (e.g., ablation) from a second side. As used herein, a "location" may be a specific place or location, such as a point, line, two-dimensional area, and / or three-dimensional volume. As used herein, "locating" may refer to the act of determining, finding, and / or identifying a location. In general, the present disclosure includes devices for locating and / or marking a location on biological tissue, such as the wall of a heart, and related methods.

[0042] Some exemplary embodiments according to at least some aspects of the present disclosure may be used in conjunction with locating locations on a second side (e.g., the epicardium) of biological tissue that correspond to and / or utilize locations initially located on a first side (e.g., the endocardium) of the tissue. For example, during hybrid heart surgery, a cardiac electrophysiologist ("EP") may locate the location of a particular anatomical structure based on electrophysiological mapping performed on the endocardium (e.g., the inner surface of the heart wall). The surgeon may then locate and / or mark the corresponding locations on the epicardium (e.g., the outer surface of the heart wall) to guide acute treatment, staged treatment, and / or chronic post-operative follow-up treatment or diagnosis. For example, placement of one or more fiducial markers may facilitate future imaging studies, such as for confirming the stability of a left atrial appendage occlusion clip applied during hybrid left atrial appendage treatment.

[0043] Particularly when a treatment procedure must be performed in a particular manner to include or avoid a particular portion of tissue, it may be advantageous to locate and / or mark a location on the second side of the tissue that corresponds to a location initially located on the first side of the tissue. For example, the location of the portion of the tissue to be ablated may be located on the first side of the tissue, and a corresponding location may be marked on the second side of the tissue. The marking may then be used to help guide an ablation device at the portion of the tissue to be ablated. Alternatively, the location of the portion of the tissue not to be ablated may be located on the first side of the tissue, and a corresponding location may be marked on the second side of the tissue. The marking may then be used to guide the ablation device to avoid ablating the marked portion of the tissue. Some exemplary markings may be durable and / or easily detectable to facilitate subsequent use of the marking to locate the marked location.

[0044] Figure 1 is a partial cross-sectional view of heart 10 illustrating the approximate location of sinoatrial ("SA") node 12, and Figure 2-7 is a detailed cross-sectional view of heart wall 14 proximate SA node 12, illustrating exemplary operations, all in accordance with at least some aspects of the present disclosure.

[0045] refer to Figure 1 The SA node 12 is found in the heart wall 14 (e.g., myocardium) of the right atrium 16, lateral to the entrance of the superior vena cava 18. The cells of the SA node 12 generate electrical impulses that cause the heart 10 to contract. Exemplary hybrid heart procedures may include treatment of arrhythmias, such as inappropriate sinus tachycardia ("IST"), which may be caused by abnormal anatomy or physiology within the conduction system of the heart. Such procedures may include epicardial ablation near the SA node 12; however, the location of the SA node 12 may not be visually apparent when observing the epicardial surface.

[0046] refer to Figure 1-3 , a physician (e.g., an EP) may use an electrical mapping catheter 20 extending within the heart 10 (e.g., within the right atrium 16) to locate a first location 24 on a first endocardial side 22 of the heart wall 14, such as a location associated with the patient's SA node 12. For example, the EP may use known electrophysiological / electroanatomical mapping techniques to locate the location 24 of the SA node 12 on the endocardium 22. In other exemplary embodiments, other portions of the heart wall 14 may be located, such as locations associated with the atrioventricular node, ganglionic plexuses, and / or areas of arrhythmia.

[0047] refer to Figure 4, the EP can be performed by pushing the endocardium 22 using the mapping catheter 20 to generally expand the heart wall 14 outward, thereby forming a protrusion 26 on the second epicardial surface 28. The protrusion 26 can be visible (e.g., directly or using an instrument such as an endoscope) and / or mechanically detectable (e.g., directly palpable or using an instrument) on the epicardial side 28 of the heart wall 14, thereby indicating a corresponding second location 30 on the epicardium 28. It will be understood that any technique for correlating the first location 24 on the endocardial surface 22 with the second location 30 on the epicardial surface 28 can be used, including the alternative techniques described elsewhere herein.

[0048] In some alternative exemplary embodiments, second location 30 can be located electrically, for example, using an epicardially positioned instrument 21 including sensor 23. For example, similar to a proximity sensor, the instrument can be configured to sense and interpret signal amplitudes between surfaces. For example, instrument 21 can transmit an electromagnetic signal (e.g., a field or beam of electromagnetic radiation) on the second surface, and sensor 23 can look for changes in the return signal caused by an instrument (e.g., catheter 20) on the first surface to correlate tissue locations between the two instruments. In other exemplary embodiments, instrument 21 and catheter 20 can be configured to assess changes in tissue impedance across a tissue region between two opposing poles. For example, an instrument (e.g., instrument 21) on the second surface and an instrument (e.g., catheter 20) on the first surface can be used as a closed-loop system to detect tissue impedance between them. Instrument 21 and catheter 20 can be aligned on their respective tissue surfaces and translated across the tissue region to assess changes in impedance, which can be correlated to structures or regions of therapeutic interest in the tissue. For example, a second location 30 indicated by a non-focal tissue structure (e.g., the SA node) can be located by detecting a change in the impedance of the tissue (relative to the surrounding tissue) in the region between the instrument 21 and the pole of the catheter 20. It will be appreciated that similar electrical localization of the second location 30 can be performed using alternative arrangements of instruments and / or sensors in alternative exemplary embodiments. For example, the elements positioned adjacent to the first and second surfaces can be reversed.

[0049] In some alternative exemplary embodiments, the second location 30 can be magnetically located. For example, the sensor 23 of the epicardially located device 21 can be configured to detect one or more endocardially located magnets (e.g., magnets associated with the mapping catheter 20). In other exemplary embodiments, the one or more magnets 25 in the epicardially located device 21 can be configured to magnetically interact with (e.g., attract) one or more magnets 27 associated with the mapping catheter 20.

[0050] refer to Figure 5The same or another physician (e.g., a cardiac surgeon) may then mark a second location 30 on the epicardial side 28 of the heart wall 14, for example, by placing a marker 32 at the second location 30 on the epicardial surface 28, which may be indicated by the protrusion 26. It will be appreciated that any marking device and / or marking technique, such as those described elsewhere herein, may be used to facilitate marking the second location 30 with the marker 32. Generally, as used herein, a "marker" may refer to an indication of a location. For example, a marker may include a marking substance applied to a specific portion of a surface (e.g., a permanent or semi-permanent ink or dye, a bioabsorbable / dissolvable patch, a permanent fiducial marker that may or may not be radiopaque), an object placed on the surface, and / or a tissue injury. In some exemplary procedures, the physician may perform epicardial electrical mapping, for example, before and / or after placing the marker 32 on the epicardial surface 28.

[0051] refer to Figure 6 , the mapping catheter 20 can be at least partially withdrawn, which can remove the protrusion 26. The marker 32 can remain visible or otherwise detectable at the second location 30 on the epicardial surface 28.

[0052] refer to Figure 1 and Figure 7 , a surgeon may perform a treatment procedure, such as ablating a portion of the heart wall near the SA node 12 from the epicardium 28 side of the heart wall 14. The surgeon may access the epicardium 28 via an incision 36 through the skin 38. The surgeon may use the marker 32 to guide a treatment device, such as an ablation device 34, to ablate a desired portion of the heart wall 14. In some procedures for treating IST, it may be desirable to ablate a portion of the heart wall 14 that is near but does not include the portion of the heart wall 14 that includes the SA node 12. Therefore, the surgeon may guide the ablation device 34 so that it ablates the heart wall 14 near the marker 32 while avoiding the portion of the heart wall marked by the marker 32. Alternatively, for example, in other procedures, or where ablation of the SA node 12 is desired, the surgeon may guide the ablation device 34 so that it ablates the portion of the heart wall marked by the marker 32. Some exemplary embodiments may be used in conjunction with long-term follow-up procedures or diagnostics. For example, the future procedure facilitated by the marker 32 may be surgical, endocardial / interventional, and / or radiation therapy in nature.

[0053] Although the foregoing description has focused on locating and marking a location associated with the SA node, it will be understood that alternative embodiments according to at least some aspects of the present disclosure may be utilized in conjunction with procedures involving other portions of the heart and / or other biological tissues that may include similar devices and / or operations. Furthermore, although the foregoing description has focused on marking a second location on a relatively outer surface (e.g., epicardium) based on a first location on a relatively inner surface (e.g., endocardium), it will be understood that various alternative exemplary embodiments according to at least some aspects of the present disclosure may be utilized to mark a second location on a relatively inner surface (e.g., endocardium) based on a first location on a relatively outer surface (e.g., epicardium) using substantially similar apparatus and techniques.

[0054] According to at least some aspects of this disclosure, Figure 8 is a cross-sectional view of an exemplary sheathed Kittner dissector 100 with the sheath 102 in an extended configuration, and Figure 9 1 is a cross-sectional view of a sheathed Kittner dissector 100 with the sheath 102 in a retracted configuration. Generally speaking, the illustrative sheathed Kittner dissector 100, which is an exemplary marking device, includes an elongated shaft 104 having an absorbent tip 106 disposed distally thereon. For example, the tip 106 may comprise an absorbent fabric. The sheath 102 is disposed about the shaft 104 and may be in an extended configuration ( Figure 8 ) and retracted configuration ( Figure 9 ). In the extended configuration, sheath 102 at least partially covers the distal portion of shaft 104 and tip 106. In the retracted configuration, at least a portion of tip 106 is exposed and arranged to contact tissue to be marked ("target tissue").

[0055] Generally speaking, the sheath 102 can be configured such that, in the extended configuration, the sheath 102 prevents the tip 106 from contacting tissue or surfaces other than the target tissue. For example, the distal portion of the sheath 102 can extend distally beyond the tip 106. In some exemplary embodiments, at least a portion of the sheath 102 can be substantially transparent. This can allow the user to visualize the relative position of the endoscopic Kittner dissector 100 with respect to the target tissue. The sheath can also include features such as an insufflation seal to prevent pressure loss from the chest cavity during the procedure; a visible depth index marker (radiopaque or otherwise); a friction feature to maintain the sheath in position relative to the Kittner dissector; or a handle, etc.

[0056] The absorbent tip 106 can be immersed in or otherwise loaded with a liquid marking substance (e.g., ink or dye, radiopaque contrast agent) for marking tissue. For example, the Kittner dissector 100 can be supplied with the tip 106 pre-moistened with the marking substance. In other embodiments, the tip 106 can be pre-loaded with a dry marking substance that can be hydrated upon use. In other embodiments, the Kittner dissector 100 can be supplied with a cartridge containing a liquid marking substance, and the tip 106 can be loaded with the marking substance upon use. In some exemplary embodiments, as the marking substance wicks onto the sheath, the sheath 102 can serve as an ink well for the Kittner dissector, which is loaded with the marking substance. By pulling the tip 106 back into the sheath 102, the tip 106 can be at least partially reloaded with the marking substance. Generally speaking, the tip 106 can be configured to carry enough marking substance to allow the user to create small "dot" marks and / or more complex shapes on the target tissue as desired.

[0057] Generally speaking, the sheathed Kittner dissector 100 can be prepared for use, for example, by loading the distal end 106 with a marking substance and / or placing the sheath 102 in an extended configuration ( Figure 8 ). The sheathed Kittner dissector 100 can be introduced into the surgical space, for example, via a minimally invasive surgical access device (e.g., a sheath or trocar) or directly through a skin incision. Once in the surgical space, the sheath 102 can be advanced to the target tissue and aligned to direct the marking substance from the distal end 106 to the desired location on the target tissue. The user can press and hold the sheath 102 against the target tissue. The sheath 102 can be withdrawn to a retracted configuration ( Figure 9 ), thereby exposing the distal end 106, and the distal end 106 can be used to mark the target tissue by applying a marking substance (eg, ink) to the target tissue. The sheath 102 can be returned to the extended configuration ( Figure 8 ), and the sheathed Kittner dissector 100 can be withdrawn from the surgical field.

[0058] Figure 9 The sheathed Kittner dissector 100 in includes an optional microneedle 108 that can be configured to at least partially penetrate the target tissue, which can facilitate application of a marking substance beneath the surface of the target tissue in a manner similar to a tattoo.

[0059] Figure 10 and Figure 11 is a cross-sectional view illustrating an exemplary method of marking the epicardium 28 using the sheathed Kittner dissector 100 according to at least some aspects of the present disclosure. Figure 2-7 As described above, the sheathed Kittner dissector 100 is used to apply the marker 32 at the second location 30 associated with the SA knot 12. Figure 10, the sheathed Kittner dissector 100 can be advanced with the sheath 102 in the extended configuration to align the distal portion of the sheath 102 with the protrusion 26 indicating the second location 30, which can include target tissue. The shaft 104 can then be moved distally relative to the sheath 102 to contact the tip 106 at the second location 30 with the second surface (e.g., epicardium) 28, thereby placing a marker 32 comprising a marking substance (e.g., ink) thereon from the tip 106, as shown. Figure 11 As shown in .

[0060] It will be appreciated that various illustrative sheathed Kittner dissectors 100 according to the present disclosure may be used to mark locations, such as second location 30, in any desired size or shape. For example, sheathed Kittner dissector 100 may be used to mark points, lines, and / or two-dimensional areas.

[0061] According to at least some aspects of this disclosure, Figure 12 is a side view of an exemplary marking instrument 200 in a retracted configuration, and Figure 13 2 is a side view of a marking instrument 200 in an extended configuration. Generally speaking, the illustrative marking instrument 200, which is an exemplary marking device, includes an elongated shaft 202 having a distally disposed tip 204. For example, the tip 204 may include an absorbent fabric. The tip 204 may be retractable in a retracted configuration ( Figure 12 ) and protruding structures ( Figure 13 ) between the shaft 202 and the distal end 204. The movable member can be positioned (e.g., slidably) longitudinally between the distal end 204 and the distal end 204. The positioning of the movable member can be controlled by a spring-loaded button 206, which can be disposed proximally, such as on a handle 208. Extension of the movable member can be limited by a stop on the button member 206 that mates with the handle member 208. In the retracted configuration, the distal end 204 is substantially located within the shaft 202, such that the distal end 204 does not mark adjacent tissue. In the extended configuration, at least a portion of the distal end 204 is exposed (e.g., extends distally beyond the shaft 202) and is positioned to contact target tissue. In some exemplary embodiments, suction can be applied downwardly along the lumen of the device to help maintain the instrument in place during use.

[0062] The tip 204 can be immersed in or otherwise loaded with a liquid marking substance (e.g., ink or dye) for marking tissue. For example, the tip 204 can be supplied with the marking instrument 200 pre-moistened with the marking substance. In other embodiments, the tip 204 can be pre-loaded with a dry marking substance that can be hydrated at the time of use. In other embodiments, the marking instrument 200 can be supplied with a cartridge containing a liquid marking substance, and the tip 204 can be loaded with the marking substance at the time of use. Generally speaking, the tip 204 can be configured to carry enough marking substance to allow the user to create small "dot" marks or more complex shapes on the target tissue as desired.

[0063] Generally speaking, the marking instrument 200 can be prepared for use, for example, by loading the tip 204 with a marking substance and / or placing the tip 104 in a retracted configuration ( Figure 12 ). The marking instrument 200 can be introduced into the surgical space, for example, through a minimally invasive surgical access device (e.g., a sheath or trocar) or directly through a skin incision. Once in the surgical space, the shaft 202 can be advanced to the target tissue and aligned to direct the marking substance from the distal end 204 to the desired location on the target tissue. The distal end 204 can be extended ( Figure 13 ), and the tip 204 can be used to mark the target tissue by applying a marking substance to the target tissue. The tip 204 can be returned to the retracted configuration ( Figure 12 ), and the marking instrument 200 can be withdrawn from the surgical field.

[0064] In some exemplary embodiments, a marking device, such as marking instrument 200, may include one or more features configured to facilitate guiding the tip 204 to a desired location. Figure 12 , the marking device 200 may include one or more sensors, such as an impedance sensor 210, which may be configured to sense the impedance of the target tissue. As another example, the marking device 200 may include one or more magnets 212 that may be attracted or repelled by a corresponding magnet associated with another device, such as the magnet 27 ( Figure 4 ). Thus, after the marking instrument 200 has been introduced into the surgical space, the tip 204 can be guided to the desired location using magnetic attraction, magnetic repulsion, and one or more impedance measurements of the tissue. It will be appreciated that similar guidance can be used in conjunction with other exemplary marking devices, such as the sheathed Kittner dissector described above.

[0065] In some exemplary embodiments, a marking device, such as marking instrument 200, may include one or more features configured to facilitate stabilizing marking instrument 200. For example, referring to Figure 13, the marking instrument 200 may include a distal suction opening 214 that is operatively connected to a suction source 216 via a suction tube 218. Applying suction may temporarily secure the distal suction opening 214 to the tissue, thereby stabilizing the marking instrument 200. As another example, the magnet 212 may be configured to be attracted by a corresponding magnet associated with another instrument (e.g., the magnet 27 of the mapping catheter 20). Figure 4 )) attraction, thereby stabilizing the marking instrument 200. Thus, before marking tissue, the marking instrument 200 can be stabilized, for example, by using suction and / or using magnetic attraction. It will be understood that similar stabilization can be used in conjunction with other exemplary marking devices, such as the sheathed Kittner dissector described above.

[0066] Figure 14 and Figure 15 is a partial cross-sectional view illustrating an exemplary method of using a marking instrument 200 to mark the epicardium 28 according to at least some aspects of the present disclosure. Figure 2-7 As described above, the marking instrument 200 is used to apply the marker 32 at the second location 30 associated with the SA knot 12. Figure 14 , the marking instrument 200 with the distal end 204 in the retracted configuration can be advanced into the surgical space adjacent the protrusion 26 indicating the second location 30, which can include target tissue. The distal end 204 can be placed in the extended configuration. Figure 15 The shaft 202 may be manipulated to bring the distal end 204 into contact with the second surface (eg, epicardium) 28 at the second location 30 , thereby positioning a marker 32 comprising a marking substance thereon from the distal end 204 .

[0067] It will be appreciated that the various illustrative marking instruments 200 according to the present disclosure can be used to mark locations, such as the second location 30, in any desired size or shape. For example, the marking instrument 200 can be used to mark points, lines, and / or two-dimensional areas.

[0068] Figure 16 is an isometric view of an exemplary patch 300 according to at least some aspects of the present disclosure. Generally speaking, the illustrative patch 300 is an object that can be placed on biological tissue to mark a location. The patch 300 can be composed of a substrate 302. The patch 300 can include a marker 32 as described elsewhere herein.

[0069] In some exemplary embodiments, substrate 302 may be composed of one or more bioresorbable materials. Examples of such substrates 302 include oxidized regenerated cellulose (ORC), polyglycolic acid (PGA) felt, collagen sponge (which may be coated with fibrinogen and / or thrombin), monofilament mesh (e.g., poly-4-hydroxybutyrate (P4HB)), and / or biosynthetic web scaffolds (e.g., polyglycolic acid (PGA) and trimethylene carbonate (TMC)). Some exemplary bioresorbable substrates 302 may be radiopaque or doped to be radiopaque. For example, in some exemplary embodiments, substrate 302 may include a membrane formed by molding gelatin or oxidized regenerated cellulose. Some patches 300, such as those including a substrate 302 composed of a bioresorbable material, may be placed on biological tissue during surgery and / or may be left in place on the tissue after surgery. Some such patches 300 may be absorbed by the body over time. Alternatively, the patch 300 may be removed from the biological tissue before the procedure is concluded.

[0070] In some exemplary embodiments, substrate 302 may be comprised of a non-bioabsorbable material. Some such substrates 302 may be comprised of biocompatible materials, such as polyester, polyurethane, silicone, or polyolefins (e.g., polypropylene or polyethylene). Some exemplary non-bioabsorbable substrates 302 may be radiopaque or may be doped to be radiopaque. Some patches 300, such as those comprising substrate 302 comprised of a non-bioabsorbable material, may be placed on biological tissue during surgery and / or removed from biological tissue prior to completion of the procedure. Alternatively, patch 300 may be left in place on the tissue after surgery. These configurations may or may not induce fibrotic infiltration with respect to long-term stability.

[0071] In some exemplary embodiments, patch 300 can perform functions related to a therapeutic procedure. For example, patch 300 including electrically insulating substrate 302 can be used in conjunction with an ablation procedure. Patch 300 can electrically insulate at least some underlying tissue by interrupting the electrical ablation signal. For example, electrical isolation can be achieved by incorporating a coating such as polyamideimide (see Elantas PDG Elan-Film Insulation Sheet) or electrical-grade polyester (see Von Roll DMD-100 White Triplex Flexible Laminate Sheet), or by incorporating an insulating material such as polyimide into the patch's formulation (see DuPont Kapton HPP Low Shrinkage Polyimide Film Sheet catalog). Thus, such a patch 300 can serve as a protective patch for a portion of underlying tissue, for example, to prevent unintended ablation caused by the patch's electrically insulating properties.

[0072] In some exemplary embodiments, the patch 300 can be provided in a dry state. The patch 300 can be hydrated before use, or it can be applied to the target tissue in a dry state. Alternatively, the patch can be provided in a hydrated state.

[0073] In some exemplary embodiments, the patch 300 can facilitate the application of a marking substance, such as ink or dye 304, to biological tissue to include the marker 32. Specifically, the substrate 302 can be used to retain the dye 304 and / or facilitate the application of the dye 304 to the target tissue. Generally speaking, using the patch 300 to deliver the dye 304 can allow for more consistent formation of the marker 32, thereby potentially allowing more users to perform safer surgical procedures, and / or potentially preventing the dye 304 from spreading or rubbing off the target tissue. In cardiovascular surgery, using the patch 300 to apply the dye 304 can improve the safety of beating heart surgery because it can reduce the risk of damaging the heart with the potentially traumatic end of a surgical marker or similar device.

[0074] In some exemplary embodiments, patch 300, including substrate 302, may be provided separately from dye 304. Prior to use, liquid dye 304 mixed with water or dry dye 304 may be absorbed into substrate 302. Patch 300 may then be placed on target tissue. At least some of dye 304 from patch 300 may be transferred to the target tissue, thereby forming visible marker 32 on the target tissue.

[0075] In other exemplary embodiments, the patch 300, including the substrate 302 and the dye 304, can be provided in a dry state. Prior to use, the patch 300 can be moistened, for example, with water. The hydrated patch 300 can then be placed on the target tissue. At least some of the dye 304 from the patch 300 can be transferred to the target tissue, thereby forming a visible marker 32 on the target tissue.

[0076] In other exemplary embodiments, the patch 300 including the substrate 302 and the dye 304 can be provided in a hydrated state. The hydrated patch 300 can be placed on the target tissue, and at least some of the dye 304 from the patch 300 can be transferred to the target tissue, thereby forming a visible marker 32 on the target tissue.

[0077] In some exemplary embodiments, a patch 300 configured to apply a marking substance, such as a dye 304, to a target tissue can be applied to the target tissue, left in place to allow at least some of the marking substance to transfer to or act on the target tissue, and can be removed from the target tissue.

[0078] The patch 300 can be configured to adhere to the target tissue in a hydrated and / or dry state. The patch 300 can be formed in standard sizes and / or can be made into a specific size and / or shape based on the target tissue and / or patient. In some embodiments, the patch 300 can be generally in the form of a small circle or oval, such as Figure 16 . However, the size of the dye delivery patch is not limited and can be of various shapes and / or sizes depending on the target tissue. For example, some patches 300 (e.g., substrate 302) can be provided in a ready-to-use size and shape. Alternatively, some patches 300 (e.g., substrate 302) can be provided in a size larger than the desired size and / or shape for use. The user can then cut the patch 300 (e.g., substrate 302) into the desired size and / or shape for use.

[0079] Some exemplary embodiments are described herein as using various marking substances to place markers on target tissue. Generally speaking, it is within the scope of the present disclosure to utilize any ink, dye, or other marking substance in conjunction with any embodiment described herein, as well as any such marking substance. For example, in various illustrative embodiments, dyes such as methylene blue, gentian violet, brilliant blue FCF, and Evans blue may be used as marking substances.

[0080] For example, in some exemplary embodiments, the marker and / or marking substance may include a radiopaque substance that facilitates detection of the marker using fluoroscopy. If the marker remains in the patient's body, the marker can be visualized using fluoroscopy, for example, after a surgical procedure. Various known contrast agents can be used, such as iodine, including ioversol (a compound containing organically bound iodine), or barium sulfate compounds. In some exemplary embodiments, the marking substance may include an ink or dye to facilitate direct or endoscopic visibility, as well as a radiopaque agent to facilitate fluorescence detection. In other embodiments, the marking substance may include only visible marking substances (e.g., ink or dye) or only radiopaque marking substances. Some exemplary embodiments may include markers and / or marking substances that contain at least one radionuclide (e.g., iodine-131 or technetium-99).

[0081] Some exemplary embodiments may include markers and / or marking substances comprising at least one magnetic substance (e.g., a ferromagnetic material). Generally speaking, as used herein, "magnetic substance" may refer to a material that is inherently magnetic or a material that is capable of being attracted to a magnet. For example, the magnetic substance used in conjunction with the marker and / or marking substance can be used to facilitate subsequent detection and / or positioning of a previously placed marker. Additionally, in some exemplary embodiments, the magnetic properties of the marker and / or marking substance comprising a magnetic substance can be utilized to facilitate applying the marker and / or marking substance to a particular location, for example, by attracting the magnetic substance on a second surface to a magnet on a first surface (e.g., magnet 27 associated with mapping catheter 20). For example, the marker and / or marking substance can be magnetically located at a second location by attracting the second location using a magnet at a first location on a first surface.

[0082] Figure 17 is a partial cross-sectional view illustrating an exemplary method of applying a patch 300 according to at least some aspects of the present disclosure. In this example, as shown above in conjunction with Figure 2-7 As described, patch 300 may include marker 32 disposed at second location 30 associated with SA node 12, or patch 300 may facilitate delivery of a marking substance including marker 32. Patch 300 may be disposed on epicardial surface 28 using a surgical instrument such as grasper 306.

[0083] In some exemplary embodiments, marker 32 may include a tissue lesion, such as a lesion created by a radiofrequency ("RF") ablation device and / or a cryosurgical device. Figure 18is a detailed cross-sectional view of heart wall 14 illustrating an RF ablation device 40, according to at least some aspects of the present disclosure, forming a marker 32 comprising a lesion on second (epicardial) surface 28. In some exemplary embodiments, RF ablation may be performed at relatively low energy levels. Thus, other than forming visually apparent marker 32, the ablation may not significantly affect the structure and / or function of the ablated tissue. In some exemplary embodiments, the lesion may heal over time. Figure 19 FIG2 is a detailed cross-sectional view of heart wall 14 showing a cryosurgical device 42 forming a marker 32 including ice visible on second (epicardial) surface 28, in accordance with at least some aspects of the present disclosure. In this exemplary embodiment, cryosurgical device 42 applies freezing to first (endocardial) surface 22 near first location 24. As cryosurgical device 42 is cooled, tissue freezes, thereby forming ice, including marker 32, which becomes visible on second surface 28. In alternative exemplary embodiments, RF ablation device 40 may be applied to first (endocardial) surface 22 to form a lesion visible on second (epicardial) surface 28, and / or cryosurgical device 42 may be applied to second (epicardial) surface 28 to form a visually apparent ice.

[0084] Figure 20 is an isometric view of biological tissue 400 having exemplary markers 32a, 32b, 32c, 32d, and 32e thereon, in accordance with at least some aspects of the present disclosure. In general, the exemplary markers 32a, 32b, 32c, 32d, and 32e represent illustrative examples of various markers (e.g., marker 32) described herein. For example, the markers 32a, 32b, 32c, 32d, and 32e can take the form of a marking substance (e.g., ink or dye) applied by the sheathed Kittner dissector 100 or marking instrument 200, an object such as the patch 300, a marking substance (e.g., ink or dye) applied by the patch 300, ice, and / or tissue damage. In general, for example, the markers described herein can take the form of circular or non-circular dots (e.g., dot 32a), lines (e.g., straight line 32b or curved line 32c), or areas (e.g., perimeter 32d or filled area 32e). As used herein, a "line" may refer to a long, thin shape, and a line may be substantially straight or may include one or more curves, bends, or angles. Markers according to the present disclosure may be standardized or may be specifically sized and / or shaped for a particular patient and / or application.

[0085] Based on the above description and the present disclosure, it should be apparent to those skilled in the art that, while the methods and apparatus described herein constitute exemplary embodiments according to the present disclosure, it is to be understood that the scope of the disclosure contained herein is not limited to the specific embodiments above and may be varied without departing from the scope defined by the appended claims. Furthermore, it is to be understood that, in general, any feature or aspect described in conjunction with one embodiment may be used in conjunction with any other embodiment. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objectives disclosed herein in order to fall within the scope of the claims, as inherent and / or unforeseen advantages may exist even though they may not be explicitly discussed herein.

Claims

1. A surgical device for marking artificially exposed biological tissue, the surgical device comprising: slender shaft; a tip distally disposed on the elongated shaft, the tip comprising an absorbent fabric material configured to absorb a marking substance; as well as a sheath having a proximal opening and a distal opening arranged to allow passage of the elongated shaft, the sheath being slidably disposed over the shaft, the sheath being longitudinally movable between an extended configuration and a retracted configuration; wherein, in the extended configuration, the sheath at least partially covers the distal portion of the shaft and the tip such that the absorbent fabric material is not used for marking; wherein, in the retracted configuration from the extended position, the sheath is advanced proximally relative to the elongated shaft such that the tip is advanced distally relative to the sheath, whereby the absorbent fabric material is used to mark a location on the biological tissue at or within the distal opening of the sheath without causing the tip to extend distally from the distal opening of the sheath.

2. The surgical device according to claim 1, wherein At least a portion of the sheath is substantially transparent.

3. The surgical device according to claim 1, wherein The tip includes at least one microneedle arranged to penetrate target tissue.

4. The surgical device according to claim 1, wherein The tip is configured to be loaded with a labeling substance.

5. The surgical device according to claim 4, wherein The marking substance includes at least one of ink and dye.

6. The surgical device according to claim 4, wherein The labeling substance includes a radionuclide.

7. The surgical device according to claim 4, wherein: The marking substance includes a radiopaque substance.

8. The surgical device according to claim 4, wherein The labeling substance includes a magnetic substance.

9. The surgical device according to claim 4, wherein: The marking substance is a liquid.

10. The surgical device according to claim 4, in, The marking substance is in a dry state; as well as Wherein, the terminal end and the labeling substance are configured to be hydrated before use.

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