Cannula system with variable tip geometry

Abstract

A cannula system for cannulating a blood vessel includes a cannula having a distal end and a proximal end. The cannula defines a cannula lumen. The cannula system further includes a tip on the distal end of the cannula. The tip defines a tip lumen connected to the cannula lumen. The tip is variable between a first shape and a second shape. The first shape has a first width suitable for passage through the lumen of the blood vessel. The second shape has a second width greater than the first width that can engage the lumen of the blood vessel to secure the tip in an appropriate position within the lumen of the blood vessel.

Description

[Background technology]

[0001] Extremely preterm birth is a leading cause of infant morbidity and mortality among children under the age of five in the United States, accounting for more than one-third of all infant deaths and half of all children diagnosed with cerebral palsy. Respiratory failure is the most common and challenging problem associated with extremely preterm birth. This is because structural and functional lung immaturity impairs gas exchange in severely preterm newborns. Advances in neonatal intensive care have improved survival rates and extended the limit of viability for preterm newborns from approximately 23 weeks to approximately 24 weeks of gestation, the transition period from the tubular to the saccular stage of lung development. Although survival is now possible, rates of chronic lung disease and other complications of organ immaturity remain high, especially in newborns born before 28 weeks of gestation. The development of a system that can support normal newborn growth and organ maturation for even a few weeks could significantly reduce morbidity and mortality in extremely preterm infants and improve the quality of life for survivors.

[0002]

[0002] A cannula system can facilitate cannulation of veins, arteries, and the like in patients, such as neonates. A cannula system typically includes a trocar or needle for puncturing the patient's body and a cannula for insertion into the patient's body through the puncture site. Some cannula systems also include a dilator used to align the cannula. The needle and dilator are inserted proximally into the cannula and must protrude a precise length through the cannula's tip. During use, the needle is used to penetrate the vessel wall and advanced until the tip of the dilator passes through the opening. The needle is then retracted, and the dilator is further advanced until the cannula reaches the appropriate depth within the vessel, after which the dilator is retracted. Simultaneously with the retraction of the dilator, a device must be engaged with the vessel to secure the cannula. The dilator must then be removed from the cannula, opening the blood passage. Because the dilator's outer diameter is relatively large, a large opening is required on the side of the cannula to allow the dilator to enter and exit the cannula lumen. Furthermore, the complexity of the fixation devices requires a large amount of space around or within the cannula, which can result in excessive occupancy and dilation of the vessel. There is also a need for a more secure connection between the cannula and the anatomical vessel. Summary of the Invention

[0003] The present disclosure fulfills this need with a variable-shape cannula tip. Accordingly, in one aspect, a cannula system for cannulating a blood vessel is provided. The cannula system includes a cannula having a distal end and a proximal end. The cannula defines a cannula lumen. The cannula system further includes a tip at the distal end of the cannula. The tip defines a tip lumen connected to the cannula lumen. The tip is variable between a first shape and a second shape. The first shape has a first width suitable for passage through the lumen of the blood vessel. The second shape has a second width greater than the first width that can engage the lumen of the blood vessel to secure the tip in an appropriate position within the lumen of the blood vessel.

[0004] In another aspect, a method of inserting a cannula into a blood vessel within tissue includes inserting a needle through a vessel wall to form a passageway within the vessel. The needle extends through a tip at the distal end of the cannula. The method also includes inserting the tip and cannula through the passageway into a cavity defined by the vessel and converting the tip from a first shape to a second shape. The first shape has a first width suitable for passage through the lumen of the vessel. The second shape has a second width greater than the first width that engages the lumen of the vessel to secure the tip in place within the lumen of the vessel.

[0005] In yet another aspect, a tip of a cannula system for cannulating a blood vessel is provided. The tip defines a tip lumen connected to a cannula lumen. The tip is variable between a first shape and a second shape. The first shape has a first width suitable for passage through the lumen of the blood vessel. The second shape has a second width greater than the first width that can engage the lumen of the blood vessel to secure the tip in an appropriate position within the lumen of the blood vessel. [Brief explanation of the drawings]

[0006] For a more complete understanding of the nature and desired objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which reference characters indicate corresponding components throughout the several views.

[0007] [Figure 1] 1 is a schematic diagram of an extracorporeal assist system. [Figure 2]

[0008] 1 is a schematic diagram of a portion of an extracorporeal assist system. [Figure 3]

[0009] FIG. 1 is an isometric view of a portion of an extracorporeal assist system. [Figure 4]

[0010] 1 illustrates a cannula system with a variable tip according to one embodiment of the present disclosure, the variable tip being in a first shape. [Figure 5]

[0011] FIG. 5 is an isometric view of a portion of the cannula system of FIG. 4, wherein the variable tip is in a second configuration. [Figure 6]

[0012] FIG. 5 is an enlarged isometric view of the variable tip portion of the cannula system of FIG. 4 illustrating the surface features of the variable tip portion. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0013] The invention is most clearly understood by reference to the following definitions.

[0009]

[0014] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0010]

[0015] Unless specifically stated or clear from the context, the term "about" as used herein is understood to mean within normal tolerances in the art, e.g., within two standard deviations of the mean. "About" may be understood to mean within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless clear from the context, all numerical values ​​set forth herein are modified by the term about.

[0011]

[0016] As used in this specification and claims, the terms "comprises," "comprising," "containing," "having," and the like have the meanings given to them in U.S. patent law and may mean "includes," "including," and the like.

[0012]

[0017] Unless specifically stated or clear from the context, the term "or" is understood herein to be inclusive.

[0013]

[0018] Ranges set forth herein are understood as shorthand for all values ​​within that range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or subrange from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 (including fractions thereof unless the context clearly dictates otherwise).

[0014]

[0019] Described herein is an improved cannula system. For example, the cannula system includes a tip with a variable geometry. This cannula system does not require a dilator and is simpler than conventional systems. Furthermore, the cannula described herein does not require slit ports or collet clamps on the side of the cannula. This cannula system also simplifies or eliminates the means and methods required for cannula placement and alignment. Furthermore, the cannula may have a smaller diameter, making it easier to align in small vessels than conventional cannulas. Furthermore, the described embodiments reduce the number of steps in the method of using the cannula, simplifying the cannulation process.

[0015] Extracorporeal Support System

[0020] As shown in Figures 1-6, one aspect of the present disclosure provides a cannula system for implementation in an extracorporeal assist system that is particularly useful for neonates.

[0016]

[0021] 1-3, system 10 is configured to provide extracorporeal support to a newborn. According to one aspect of the present disclosure, system 10 may be configured to provide a system environment similar to the environment in which a newborn develops in utero. The survival chances of a newborn removed from the uterine environment (e.g., due to premature birth), e.g., at about 23 to about 24 weeks of gestation, may be improved by placing the newborn in the environment of system 10.

[0017]

[0022] According to one aspect of the present disclosure, the system environment may be configured to accomplish any one of the following: (1) limit the neonate's exposure to light, (2) limit the neonate's exposure to sound, (3) keep the neonate immersed in a liquid environment, (4) maintain the neonate within a desired temperature range, (5) minimize exposure to environmental contaminants, or (5) any combination thereof. The system also allows the neonate to perform activities necessary for organ growth and development (e.g., neonate breathing, neonate swallowing of liquids).

[0018]

[0023] The system 10 may be configured to treat neonates (e.g., those less than 37 weeks of estimated gestation, particularly those between 28 and 32 weeks of estimated gestation) or extremely preterm neonates (e.g., those between 23 and 28 weeks of estimated gestation). While the gestational ages are described for humans, the corresponding preterm neonates of other animals may also be used. In certain embodiments, the neonate is free of underlying congenital disorders. Full-term or preterm neonates may have limited pulmonary gas exchange capacity due to congenital anomalies affecting lung development, such as pulmonary hypoplasia or congenital diaphragmatic hernia. In certain aspects, the subject may be a preterm or full-term neonate awaiting lung transplantation, for example, due to a congenital lung disease (e.g., bronchoalveolar dysplasia, surfactant protein B deficiency, etc.). Such transplant procedures are currently rare in the United States. However, the number of transplant procedures may increase with the more robust methods of lung support provided by embodiments of the present disclosure. The newborn 5 may also be a candidate for extrauterine intrapartum intervention (EXIT) delivery, such as a patient with severe airway disease who will likely be waiting a long time for definitive resection. The newborn 5 may also be a patient requiring neonatal surgery or fetoscopic procedures, particularly with preterm labor resulting in preterm delivery. According to one aspect of the present disclosure, the system 10 may be configured to maintain the newborn 5 within the system 10 for a required period of time (e.g., days, weeks, or months until the newborn 5 is able to survive without the system 10). The system 10 may be operable to maintain the newborn 5 for at least 7 days, at least 14 days, at least 21 days, at least 28 days, at least 35 days, at least 42 days, at least 49 days, or at least 56 days.

[0019]

[0024] The system 10 includes a neonatal chamber 100 configured to accommodate a neonate 5, a physiological saline solution (PSS) circuit configured to flow (e.g., at a constant flow rate) through the neonatal chamber 100, and an oxygenation circuit 400 (e.g., an extracorporeal membrane oxygenation system) configured to remove carbon dioxide from the neonate's blood and to oxygenate the neonate's blood.

[0020]

[0025] System 10 is configured to maintain newborn 5 within newborn chamber 100 immersed in PSS. System 10 is further configured to enable oxygen delivery circuit 400 to provide sufficient gas exchange to sustain life for newborn 5. In this manner, system 10 provides an environment similar to that in utero to promote the continued growth and development of newborn 5. System 10 may also include devices, such as carts, to facilitate monitoring, care, and transport of newborn 5 within a medical facility.

[0021]

[0026] According to one aspect of this disclosure, the system 10 may be as described in U.S. Pat. No. 11,471,351, entitled "System and Method Configured to Provide Extracorporeal Support for Premature Fetus."

[0022]

[0027] The oxygen delivery circuit 400 can be connected to the neonate 5 via a venous / venous arrangement (e.g., using a mechanical pump included in the system 10). Alternatively, the oxygen delivery circuit 400 can be connected to the neonate 5 via an arterial / venous arrangement. A cannula can be placed in the neonate's 5 large cervical vessels (e.g., carotid artery, jugular vein) to connect the neonate's 5 circulatory system to the oxygen delivery device 500. Placement in the large cervical vessels can avoid problems with umbilical vessels, such as vasospasm and cannula instability. A sleeve can be attached to the outer portion of the cannula (e.g., to increase the tension of the stabilizing sutures). The sleeve can be made of silicone and can be, for example, approximately 1-10 cm long, particularly approximately 3-5 cm long. The cannula can be sutured to the neonate 5 (e.g., via a pre-attached sleeve) to secure the cannula to the neonate's neck.

[0023]

[0028] In some embodiments, the oxygen delivery circuit 400 may be connected to the neonate 5 via the neonate's umbilical cord. In such an arrangement, cannulas may be sutured to the veins and arteries of the umbilical cord. Of course, other connection arrangements may also be used. A sutureless device is described in U.S. Provisional Application No. 63 / 017,204.

[0024]

[0029] The oxygen delivery circuit 400 may include an oxygenator 500 for providing gas exchange functions, particularly oxygen (supply) and carbon dioxide (removal), to the neonate 5. The oxygenator 500 is removably connectable to the neonate 5 and, if desired, to other components of the oxygen delivery circuit 400 and system 10. The oxygenator 500 is connected to the neonate 5 via two or more fluid lines, including at least a drain line 440 and an inlet line 445. Blood flows from the neonate 5 through the drain line 440 to the oxygenator 500. The blood then passes through the oxygenator 500 and returns to the neonate 5 via the inlet line 445.

[0025]

[0030] In some embodiments, the oxygenator 500 may be configured to be disconnected and replaced while the oxygenator circuit 400 remains operational. If the oxygenator 500 is damaged or exceeds its expected lifespan (typically 8 hours based on regulatory approvals), the oxygenator circuit 400 may be configured to temporarily bypass the oxygenator 500, allowing the oxygenator 500 to be disconnected from the oxygenator circuit 400 and a freshly prepared oxygenator 500 to be connected in its place without interrupting blood flow.

[0026]

[0031] Heating and / or cooling elements 600 may be connected to system 10 and configured to regulate the temperature of one or more components of system 10 .

[0027] Cannula System

[0032] 4 illustrates a cannula system 200 according to an embodiment of the present disclosure. The cannula system may be integrated into the oxygen delivery circuit 400 described in connection with FIGS. 1-3. In some cases, the cannula may be integrated into the cannulation system described in U.S. Patent Publication No. 2021 / 0338270A1.

[0028]

[0033] 4-6, the cannula system, generally designated 200, may be deployed to cannulate a blood vessel. Cannula system 200 includes a cannula 202 having a distal end 204 and a proximal end 206. Cannula 202 defines a cannula lumen 208 extending from proximal end 206 to distal end 204. In this example, cannula 202 includes a rigid portion 205 extending proximally from distal end 204 and a flexible portion 207 extending from the rigid portion to proximal end 206.

[0029]

[0034] Cannula system 200 includes a tip 210 at the distal end 204 of cannula 202. Tip 210 defines a tip lumen 212 connected to cannula lumen 208. Tip 210 is convertible between a first shape (shown in FIG. 4) and a second shape (shown in FIGS. 5 and 6). The first shape has a first width suitable for passage through the lumen of a blood vessel. The second shape has a second width greater than the first width that can engage the lumen of a blood vessel to secure tip 210 in an appropriate position within the lumen of the blood vessel.

[0030]

[0035] Cannula system 200 includes a needle 214 sized for passage through cannula lumen 208 and tip lumen 212. Tip 210 defines a distal opening 216 positioned for needle 214 to pass through and engage a blood vessel.

[0031]

[0036] In this example, cannula 202 includes a septum seal 218 proximal to tip 210, positioned to allow needle 214 to enter or retract from cannula lumen 208. Septum seal 218 is located on flexible portion 207 of the cannula. Septum seal 218 facilitates needle 214 insertion and allows for easy needle removal without a slit port.

[0032]

[0037] Suitably, the cannula is constructed from a biocompatible material such as stainless steel, cobalt chromium alloy, titanium, nickel titanium alloy, tantalum, nickel plated tungsten, brass plated tungsten, polycarbonate, PEEK, PES, fiber reinforced plastic, or combinations thereof.

[0033] Cannula tip

[0038] An example of the tip 210 is shown in FIGS. 4 through 6. The tip 210 is variable between a first shape and a second shape. In embodiments, the second shape may differ in size and / or geometry from the first shape. For example, the tip 210 may be a perforated flexible sleeve or stent. The first shape of the tip 210 may be a tapered truncated cone. The second shape of the tip 210 may be a cylinder having a diameter. This diameter defines a width of the second shape, which is greater than the width of the first shape. For example, the width of the first shape may be approximately 1 mm or less, and the second width of the second shape may be in the range of 3 mm to 6 mm. The length of the tip 210 may be in the range of 6 mm to 11 mm. In other embodiments, the tip 210 may have another shape. For example, in some embodiments, the tip 210 may be a cuboid, a sphere, a rectangular cuboid, and / or any other suitable shape.

[0034]

[0039] As shown in FIG. 4, in the first configuration, tip 210 tapers from a larger diameter at proximal end 204 to a smaller diameter at the distal end that corresponds to the outer diameter of the needle. This smaller diameter defines the minimum width of the first configuration. Tip 210 defines a distal opening 216 positioned for the needle to pass through and engage a blood vessel at its distal end. This tapered configuration provides a smooth transition between the outer diameter of needle 214 and the outer diameter of cannula 202.

[0035]

[0040] In this example, tip 210 includes features 220 on its outer surface that are arranged to engage the inner surface of a blood vessel. The features may include ribs or protrusions to facilitate engagement and fixation of tip 210 to a blood vessel. For example, the features may be arranged in an irregular pattern on the outer surface of tip 210 (e.g., asymmetrical with respect to the transverse axis of the cannula) so that the features facilitate engagement with the blood vessel but do not impede introduction of tip 210 into the blood vessel. In other embodiments, the features are omitted.

[0036]

[0041] In this example, the tip 210 is constructed of a shape memory alloy, such as a nickel titanium (nitinol) alloy, which can facilitate shape switching of the tip 210. In another example, the tip is constructed of a biocompatible material, such as stainless steel, cobalt chromium alloy, titanium, nickel titanium alloy, tantalum, nickel plated tungsten, brass plated tungsten, polycarbonate, PEEK, PES, fiber reinforced plastic, or a combination thereof.

[0037]

[0042] A retainer may be used to secure the tip in the first or second shape. For example, the retainer may be a separate component that engages the tip 210 in the first or second shape. Alternatively, the retainer is incorporated into the tip 210 and / or the cannula 202. The retainer may be removed or adjusted to switch the tip between the first and second shapes. In some embodiments, the retainer is a bias member, a latch, a catch, and / or any other suitable retainer.

[0038]

[0043] When tip 210 is in a neutral position, tip 210 may have a first shape or a second shape and requires a force to hold or secure tip 210 in the alternative first and second shapes. Suitably, a retainer may hold tip 210 in the first and / or second shapes. In some embodiments, the retainer is omitted.

[0039]

[0044] In one embodiment, tip 210 has a second shape in a neutral state, and a retainer is incorporated into needle 214. Features on needle 214 engage and hold tip 210 in its collapsed, first shape. When the needle is removed, tip 210 is unconstrained and expands to its second shape.

[0040]

[0045] In one embodiment, tip 210 has a second shape in a neutral state, and the retainer is a sheath. For example, the sheath is placed over tip 210 to secure tip 210 in the first, folded shape. Once cannula 202 and tip 210 are positioned within a blood vessel, the sheath can be removed from tip 210. Removal of the sheath causes tip 210 to expand to the second, expanded shape.

[0041]

[0046] In one embodiment, the tip has a second shape in a neutral state and the retainer is a constraining filament that engages the tip 210. Removing the filament releases the constraint on the tip 210 and causes the tip 210 to expand to the second shape.

[0042]

[0047] In one embodiment, no retainer is required. The tip 210 is in a first shape in a neutral state. When the tip 210 is placed in a blood vessel, the bladder expands inside the tip 210, causing the bladder to plastically expand the tip 210 to a second shape, and the bladder is removed.

[0043]

[0048] In one embodiment, retainers are incorporated into tip 210 and the cannula so that the position of tip 210 relative to the cannula holds tip 210 in a first shape. For example, twisting the distal end of tip 210 relative to the cannula positions the distal end of tip 210 in a first shape. After positioning tip 210 within a blood vessel, twisting the distal end of the tip in the opposite direction relative to the cannula changes the tip to a second shape.

[0044]

[0049] In some embodiments, the tip 210 and at least a portion of the cannula 202, such as the flexible portion, are of unitary construction. The tip 210 and cannula 202 may be made of the same material, such as a nitinol shape memory alloy, to facilitate manipulation of the cannula and tip. In further embodiments, the flexible portion of the cannula proximal to the tip 210 is a deformable stent structure to facilitate expansion of the size of the tip 210 and / or an introducer element, such as a balloon. The system may also include a deformable, fluid-tight cover around or within the deformable cannula 202 to provide a fluid-tight structure.

[0045]

[0050] In one embodiment, an external collet mechanism is incorporated into cannula 202 to help clamp vascular tissue around the cannula and secure the cannula in place with tip 210 .

[0046] Cannula system and method of using same

[0051] The cannula tip can be implemented in a cannula system, such as the cannula system shown in Figure 4. For example, the cannula system can be configured to enter a target vessel, dilate an opening in the vessel wall, connect a cannula to the vessel (e.g., by inserting a portion of the cannula into the vessel through the created opening), and secure the cannula to the vessel via a tip described herein.

[0047]

[0052] The cannula system may include a needle assembly and a cannula. The needle assembly may include a needle. For example, the needle is configured to extend through an opening in a tip on the distal end of the cannula, thereby penetrating a blood vessel to form a passageway to the blood vessel. The tip and cannula may be inserted through the passageway into a lumen defined by the blood vessel.

[0048]

[0053] Suitably, the cannulation system does not require a dilator assembly. For example, the needle is housed in the tip rather than in the dilator assembly. The tip is positioned to facilitate needle manipulation and insertion of the cannula within the vessel lumen. After the needle end penetrates the vessel wall, the tip expands to secure the cannula in place and form a larger opening in the vessel. For example, the tip can be switched between a first shape having a first width suitable for passage through the vessel lumen and a second shape having a second width greater than the first width that engages the vessel lumen and secures the tip in place within the vessel lumen.

[0049]

[0054] The cannula is configured to fluidly connect to a cannulated blood vessel at one end and to a circulatory system at the other end. The cannula and tip may define a lumen extending the length of the cannula and tip.

[0050]

[0055] In one embodiment, the cannula system provides a method for a clinician to securely attach a cannula to a cannulation area, such as, but not limited to, a blood vessel. In one example, a needle passes through a septum seal, passes through a cannula lumen, and exits at a tip at the distal end of the cannula. The tip has a first shape in which the tip tapers from a larger diameter at the distal end to a smaller diameter corresponding to the outer diameter of the needle. This tapered shape provides a smooth transition between the outer diameter of the needle and the outer diameter of the cannula. During cannulation, the needle is used to penetrate the vessel wall. The cannula is advanced so that the distal end of the tip passes through the opening and enters the vessel. Once the distal end of the tip is within the vessel, the needle is retracted within the lumen defined by the tip. The cannula assembly is advanced until the entire tip and at least a portion of the rigid cannula portion are positioned within the vessel lumen.

[0051]

[0056] The cannula is then inserted into the lumen defined by the blood vessel. Once the cannula is in place, the method includes switching a tip on the distal end of the cannula from a first shape to a second shape. The second shape has a second width greater than the first width of the first shape that engages the lumen of the blood vessel to secure the tip in place within the lumen of the blood vessel. The expanded second shape presses against the inner surface of the blood vessel, providing an open pathway from the lumen of the blood vessel to the cannula lumen.

[0052]

[0057] When the tip is in the second expanded configuration, the needle can be passed through the cannula lumen and removed from the blood vessel and the tip.The cannula system may include a septum seal for inserting and removing the needle from the cannula.

[0053]

[0058] While preferred embodiments of the invention have been described using specific language, it is to be understood that such description is for purposes of illustration only and that changes and modifications are possible without departing from the spirit or scope of the following claims.

[0054] Incorporation by Reference

[0059] The entire contents of all patents, published patent applications, and other references cited herein are expressly incorporated by reference in their entirety.

Claims

1. 1. A cannula system for cannulating a blood vessel, comprising: a cannula having a distal end and a proximal end and defining a cannula lumen; a tip on the distal end of the cannula defining a tip lumen connected to the cannula lumen; the tip is variable between a first shape and a second shape; the first shape has a first width suitable for passage through a lumen of the blood vessel; The second shape has a second width greater than the first width to engage the lumen of the blood vessel and secure the tip in place within the lumen of the blood vessel.

2. The cannula system of claim 1 , wherein the cannula comprises a rigid portion extending from the distal end and a flexible portion extending from the rigid portion to the proximal end.

3. a needle sized to fit through the cannula lumen and the tip lumen; The cannula system of claim 1 , wherein the tip defines a distal opening positioned so that the needle extends out of the tip lumen and engages the blood vessel.

4. The cannula system of claim 3 , wherein the cannula includes a septum seal proximal to the tip and positioned so that the needle enters the cannula lumen.

5. the tip is a perforated flexible sleeve; the first shape of the tip is a truncated cone; The cannula system of claim 1 , wherein the second shape of the tip is cylindrical.

6. The cannula system of claim 1 , wherein the tip comprises a feature on an outer surface of the tip and positioned to engage an inner surface of the blood vessel.

7. The cannula system of claim 6 , wherein the features are arranged in an irregular pattern on the outer surface of the tip.

8. The cannula system of claim 1 , wherein at least one of the cannula and the tip is constructed from a nickel-titanium shape memory alloy.

9. a retainer that fixes the tip portion in the first shape or the second shape; The cannula system of claim 1 , wherein the retainer is removed or adjusted to switch the tip between the first and second configurations.

10. 10. The cannula system of claim 1, wherein the cannula is constructed from stainless steel, cobalt chromium alloy, titanium, nickel titanium alloy, tantalum, nickel-plated tungsten, brass-plated tungsten, polycarbonate, PEEK, PES, fiber-reinforced plastic, or combinations thereof.

11. The cannula system of claim 1 , wherein the cannula system is configured to be operably connected to an extracorporeal membrane oxygenation system.

12. The cannula system of claim 1 , wherein the blood vessel is the umbilical cord vasculature of a newborn.

13. 1. A method of cannulating a blood vessel in tissue, comprising: inserting a needle through the blood vessel to form a passageway within the blood vessel, the needle extending through a tip on the distal end of a cannula; inserting the tip and the cannula through the passageway into a cavity defined by the blood vessel; transitioning the tip from a first shape to a second shape, the first shape having a first width suitable for passage through the lumen of the blood vessel, and the second shape having a second width greater than the first width that engages the lumen of the blood vessel to secure the tip in place within the lumen of the blood vessel; A method comprising:

14. 14. The method of claim 13, further comprising inserting the needle through a septum seal of the cannula and into the cannula lumen.

15. 14. The method of claim 13, further comprising removing the needle from the cannula lumen when the tip is in the second configuration.

16. A distal end of a cannula system for inserting a cannula into a blood vessel, comprising: the tip defines a tip lumen connected to the cannula lumen; the tip is variable between a first shape and a second shape; the first shape has a first width suitable for passage through a lumen of the blood vessel; The tip has a second width that is greater than the first width and that can engage the lumen of the blood vessel to secure the tip in place within the lumen of the blood vessel.

17. The tip of claim 16 , wherein the tip defines a distal opening positioned for a needle to pass therethrough and engage the blood vessel.

18. 17. The tip of claim 16, wherein the tip is constructed from stainless steel, cobalt chromium alloy, titanium, nickel titanium alloy, tantalum, nickel plated tungsten, brass plated tungsten, polycarbonate, PEEK, PES, fiber reinforced plastic, or combinations thereof.

19. The tip of claim 16, wherein the tip is a perforated flexible sleeve.

20. the first shape of the tip is a truncated cone; The tip of claim 16 , wherein the second shape of the tip is cylindrical.

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