Patent Application
20170173306
The present invention is generally related to splittable needles for use as medical devices aiding cardiac catheterization and peripheral and coronary intervention.
Splittable needles are used for aiding catheterization to the heart (cardiac catheterization), bladder (urinary catheterization), or other lumens of the body. During cardiac catheterization, a long, thin, flexible catheter is put into a blood vessel in the arm, upper thigh, or neck of a subject and threaded to the heart. Through the catheter, diagnostic tests and treatments on the heart can be performed.
Catheters are usually placed using introducer needles, catheter introducers and guidewires. Catheter introducers are typically used in conjunction with peripherally inserted central catheters (PICC), or other relatively long and flexible medical devices, to facilitate insertion and placement of the catheter or other medical device into the patient's vasculature. Current catheter introducers include a splittable cannula and a hub with a pair of wings fixed to the proximal end of the cannula. In addition, such a catheter introducer includes an introducer needle located inside the splittable cannula with its sharp distal tip extending distally of the distal end of the splittable cannula and with its needle hub extending proximal of the wings and hub on the cannula.
When using a typical catheter introducer, the clinician grasps the needle hub so the needle bevel is facing away from the patient's skin and proceeds to insert the distal portion of the needle at the desired site in the patient's skin. The clinician continues to advance the device until venous or arterial access has been confirmed. This confirmation is usually done visually when the clinician sees blood entering a flashback chamber formed in the needle hub at the proximal end of the needle or out of the open end of the needle. After vessel puncture has been confirmed, the clinician advances the cannula distally into the patient's vessel and the needle is withdrawn. With the catheter introducer properly placed, the clinician can then insert the PICC, or other relatively long, thin and flexible medical device, into the proximal opening of the cannula and continue to advance the catheter through the catheter introducer until the catheter is properly placed in the patient's vasculature.
Alternatively, the introducer needle can be first placed into the patient's vasculature without the catheter introducer. A guidewire is then inserted through the introducer needle into the patient's vasculature. The introducer needle is then retracted leaving the guidewire in place to provide a track or guide for the catheter introducer, and dilator if used, to follow into the patient's vasculature. A catheter is then inserted into the catheter introducer over the guidewire. This greatly facilitates the placement of a line into a patient's vasculature. After placement of the PICC, the clinician grasps the wings and pulls them apart to split the splittable introducer. In this way, the splittable introducer can be removed from the patient over any hub located on the proximal end of the PICC.
Examples of such devices are described in U.S. Pat. No. 4,957,488, U.S. Pat. No. 6,027,480, U.S. Pat. No. 8,758,302, and U.S. Pat. No. 8,974,411; in U.S. Publication Nos. US 2007/0135768, US 2009/0187147, US 2012/0157854, and US 2013/0217989; and in a U.K. Publication No. GB 2 278 060.
However, some of these devices are no longer available for clinical use and have been discontinued due to malfunctioning. For example, following placement of a PICC with a break-away splittable needle introducer, the needle did not split along its entire length. The two parts of the splittable needle remained connected at the junction of the needle and the hub (Device: Splittable Needle Introducer. MedSun Newsletter, 61, June 2011). Another splittable needle introducer for PICC and Midline catheters was reported to malfunction on at least three separate occasions. The splittable needle introducer did not split following placement of the PICC, causing removal of the entire line (http://www.patientsville.com/devices/splittable-needle-introducer.htm; accessed Mar. 16, 2015).
These malfunctions indicate that there remains a need for splittable needles with efficient alignment, locking and splitting mechanisms.
Therefore, it is an object of the present invention to provide splittable needles with parts that efficiently split along the entire length of the needle for safe removal of the splittable needle.
It is a further object of the present invention to provide splittable needles with parts that align and lock for efficient catheter delivery.
Described herein are splittable needle assemblies having a hollow shaft and opposed distal ends and proximal ends, the distal ends having a tip for insertion into a body and the proximal ends having a clamp and a locking hub. The hollow shafts of the splittable needle assemblies split into at least two elements. The at least two elements are joined together by the clamp.
In some embodiments, the clamp is positioned at the proximal end of the hollow shaft before the locking hub and has an alignment element for aligning the at least two elements and tightly joining together to form the hollow shaft of the splittable needle. In some embodiments, the clamp includes at least two handles and a securing region, wherein the at least two handles are radially protruding from the securing region, and are flexibly joined. In other embodiments, the clamp is a spring-loaded clamp.
In preferred embodiments, the alignment element is located at the securing region of the clamp. The alignment element is formed of matingly-fitted elements comprising protrusions, recessions, cuts, and stepped ridges.
In some embodiments, the at least two elements of the splittable needle assembly separate when the clamp handles are brought closer together. In other embodiments, the at least two elements separate when introduced into a body lumen.
In some embodiments, the at least two elements are magnetically joined together to form the hollow shaft of the splittable needle. In other embodiments, the at least two elements are coated by a polymer-mixture coating and joined together to form the hollow shaft of the splittable needle. In yet other embodiments, the at least two elements are joined together with a biodegradable adhesive to form the hollow shaft of the splittable needle.
Generally, the splittable needles described herein are assembled to form needles with sizes ranging from 7 Gauge (g) to 33 g.
Generally, the locking hub of the splittable needle assemblies described herein is configured for locking with additional devices comprising syringes, delivery devices, valves, filters, pumps and pouches. In some embodiments, the splittable needle assemblies described herein have a locking hub with a locking alignment element. Typically, the locking alignment element is formed of matingly-fitted elements comprising protrusions, recessions, cuts, and stepped ridges.
Also provided are kits containing a plurality of individually wrapped and sterilized splittable needle assemblies and instructions for use.
Also provided are methods of accessing a body lumen or tissue of a subject using the splittable needle assemblies described herein.
As used herein, the term “splittable needle” refers to a needle in a shape of a tube with a hollow shaft that is splittable to at least two equal or unequal longitudinal elements.
As used herein, the term “splittable needle assembly” refers to a device containing individual parts assembled together. The individual parts include two or more longitudinal elements of the splittable needle and clamp parts.
As used herein, the term “clamp parts” refer to the elements of a device, that when assembled, form a clamp.
As used herein, “longitudinal axis X” refers to a longitudinal axis that runs from the front end F to the rear end R of the splittable needle and passes through the bore of the needle.
As used herein, “longitudinal plane A” refers to a plane that passes through the longitudinal axis X of the splittable needle, dividing the needle into symmetric halves.
As used herein, the term “front end F” and the term “distal end” refer to the distal tip of a splittable needle that is located away from the locking hub, and that pierces and enters subject's tissue.
As used herein, the term “rear end R” and the term “proximal end” refer to the proximal end of a splittable needle located opposite to the front end F, and harboring the locking hub.
As used herein, the term “alignment” refers to a position of one part of the splittable needle relative to the other. As such, the term “alignment mechanism” refers to a mechanism that places one part of the splittable needle precisely aligned with the other part of the needle when the needle is assembled.
As used herein, the term “locking” refers to the action of locking one part of the splittable needle into the other. As such, the term “locking mechanism” refers to a mechanism that achieves locking of one part of the splittable needle into the other without disturbing the alignment of the assembled splittable needle.
As used herein, the term “splitting” refers to the action of separating, splitting, pulling, tearing, or peeling the individual longitudinal parts of the splittable needle from each other back into the respective individual longitudinal parts.
As used herein, the term “matingly” refers to a manner of joining at least two elements, wherein one element is configured to tightly fit within the other element.
Generally, the splittable needle assembly described herein has splittable needle, a locking hub and a clamp.
1. The Needle
The splittable needle is a needle split into equal or unequal parts along its longitudinal axis. The splittable needle has a tip region located at the front end of the needle.
a. The Needle Tip
The tip region may have any shape, including, but not limited to cone shape, dual gauge, bevel of various degrees, 90 degree cut (such as those used in percutaneous coronary intervention), domed and side hole domed. Typically, the tip region is beveled for ease of entry to a body lumen of a subject in need thereof.
b. The Needle Length
Typically, the needle has a length needed to reach a desired vessel. Generally, the needle length varies from 2 cm to 20 cm. Preferably, the needle length ranges from 5 cm to 9 cm. Most preferably, the needle length is 7 cm.
c. Needle Size
The needle has an external diameter and an internal bore diameter corresponding to a conventional needle gauge dimensions. A conventional needle gauge chart is presented in Table 1. Generally, the needle size is any gauge (g) that can accommodate the guidewire and the catheter assembly. Typically, the needle size ranges from 7 g to 33 g. In preferred embodiments, the range for the external diameter is from 0.75 mm to 1.15 mm, and for the internal diameter is from 0.45 to 0.75 mm, corresponding to 18 g or 21 g hypodermic needles. The internal diameter may be wider than the specified range if the needle is thin walled.
d. Needle Materials
The needle and the individual needle parts may be formed of any biocompatible needle material with desired stealth properties and resistance to corrosion. Typically, the needle parts are formed of stainless steel and is coated with nickel to prevent corrosion.
In some embodiments, the separate parts of the splittable needle may have magnetized edges. The magnetized edges may be present along the entire circumference of the edges of the needle parts. In other embodiments, only portions of the circumference of the needle edges are magnetized. The magnetized edges help with the alignment and securement of the two needle parts relative to each other to form the splittable needle for safe and secure tissue puncture and penetration.
In embodiments with magnetized edges, ferromagnetic composites are formed using methods known in the art (Zhong et al., Magnetics Conference, INTERMAG Asia 2005. Digests of the IEEE International. doi: 10.1109/INTMAG.2005.1463871 (2005)). The magnetized needles can be manufactured through powdered metallurgy methods.
In some embodiments, the edges of the needle parts are coated with a biocompatible adhesive. The adhesive allows the needle parts to come together and be held together until splitting of the needle is required. The adhesive is designed to be of a certain strength so that force applied to separate the two needle parts overcomes the adhesive strength of the adhesive and the two needle parts are separated.
In some embodiments, the separate needle parts are formed of flexible materials, such as metal alloys, and are held together by a biocompatible coating or adhesive. Once inserted into the patient, the coating or adhesive is dissolved in blood. The needle is then split into two following retraction from the vessel. In this embodiment, the front of the needle is split due to dissolving of the coating or the adhesive, while the rear of the needle is split due to a force applied to the clamps to separate the needle. In preferred embodiments, the needle parts are held together by a polymer-mixture coating like cyanoacrylates, methacrylates, epoxy, dimethacrylate esters, silicones, urethanes, phenol-formaldehydes.
2. The Locking Hub
In some embodiments, the splittable needle has a locking hub located at the rear end of the needle. Typically, the locking hub is adapted for locking with additional devices, including, but not limited to, syringes, delivery devices, valves, filters, pumps and pouches. Generally, the locking hub is formed of locking hub parts, with each part attached to a respective needle part of the splittable needle. When assembled, the locking hub parts come together to form the locking hub, just as the needle parts come together and align, forming the splittable needle assembly. In preferred embodiments, the locking hub is threaded and forms a threaded adapter, such as a Luer Lok™ (Becton Dickinson) when the splittable needle is assembled.
In some embodiments, the locking hub has a locking neck region and locking tip region. When the splittable needle assembly is split, the locking neck region and the locking tip region separate into at least two parts.
In some embodiments, the locking neck region has an alignment mechanism.
a. Alignment Mechanism of the Locking Hub
In some embodiments the at least two parts of the locking neck region have protrusions and recesses that align and fit into each other, forming an alignment mechanism. Typically, each locking neck part has at least one protrusion and/or at least one recess. When assembled, the protrusions and recesses ensure that the locking hub parts come together and align correctly, avoiding any misalignment.
b. Cavity of the Locking Hub
In a preferred embodiment, the locking hub has a cavity that extends from the locking hub to the bore of the needle. Generally, the cavity aids placement of a catheter or a guidewire into the needle. Typically, the cavity has a narrow diameter at the front end of the locking hub that matches the bore diameter of the needle. The cavity also has a wider diameter at the rear end of the locking hub where the additional devices can be locked onto the needle. This transition from a wider diameter to narrower diameter in the cavity allows for easy threading of catheters or guidewires through the needle bore.
The locking hub is typically formed of a durable plastic or metal. In preferred embodiments, the locking hub is formed of durable plastic.
3. The Clamp
Generally, the splittable needle has at least one clamp. The clamp is typically positioned over and around the splittable needle. The clamp may occupy at least 1/10, 1/9, ⅛, 1/7, ⅙, ⅕, ¼ or ⅓ of the length of the splittable needle. In preferred embodiments, the clamp occupies ¼ of the length of the splittable needle. In a preferred embodiment, the clamp allows adequate needle length to reach a desired vessel.
In some embodiments, the clamp has a flexing region and an adjacent securing region. In other embodiments, the flexing region and the securing region are one and the same region.
The clamp can be made of any material with desirable flexing properties. The clamp may be metallic, hard or soft plastic, or a combination thereof. In preferred embodiments, the clamp is formed of hard plastic like polyethylene, polytetraflouroethylene, polyvinyl chloride, polypropylene, polycarbonate, polylactide.
Typically, each of the equal or unequal parts of the splittable needle is attached to at least one clamp. Either a chemical adhesive, or a technique such as ultrasonic welding, can be used to unite the needle components to the clamp. If a chemical adhesive or a bonding agent is used, the agent is preferably biocompatible.
a. The Flexing Region
Typically, the flexing region is formed of at least two clamp handles projecting radially from the needle and placed opposite to each other. In some embodiments, the clamp handles are joined together by a flexing part or a bridge.
i. Clamp Parts
Typically, the clamp has at least two clamp handles. Preferably, the two handles of the clamp are symmetrically positioned along the longitudinal plane A of the splittable needle assembly. In some embodiments, the at least two clamp handles are shaped as elongated protruding members radially extending outwards and running along the length of the clamp and along the longitudinal plane A.
Generally, the clamp handles are positioned opposite to each other and in any direction that allows for easy gripping and flexing of the clamp. In some embodiments, the clamp handles project radially in a V shape, where they approach each other at the point of attachment to the needle. In other embodiments, the clamp handles are parallel to each other. In preferred embodiments, the clamp handles are positioned in a V shape. The shape of the clamp handles is configured for easy gripping of the clamp with fingers during insertion. In some embodiments, the shape of the clamp handles is generally flat-cuboid. In other embodiments, the handles are shaped as wings, waves, or ladles. In some embodiments, the handles have imprinted indents for finger tips to allow for easy gripping.
ii. Flexing Part
In some embodiments, the flexing part is a flexible bridge positioned anywhere in between the two clamp handles and joining the two clamp handles. Typically, the flexing part joins the middle section of one of the clamp handles with the middle section of the other clamp handle along the longitudinal plane of the splittable needle assembly. In these embodiments, the flexing part has one point of attachment to one clamp handle and another point of attachment to the other clamp handle. In preferred embodiments, each of the clamp handles can swivel about the axis of its respective point of attachment. Therefore, each of the at least two clamp handles can swivel independently about the axis of its respective point of attachment to the flexing part.
Optionally, the flexing part is configured to flex at about its center. In this embodiment, each of the clamp parts can swivel about the axis of its respective point of attachment to the flexing part, and the flexing part in turn can flex along the longitudinal plane A crossing the center of the flexing part. This embodiment allows for greater degree of motion of the clamp parts relative to each other.
In preferred embodiments, each of the clamp parts can swivel about the axis of its respective point of attachment to the flexing part, and the flexing part does not flex about its center. In preferred embodiments, the clamp parts are positioned in a V shape, and approach each other to form the securing region of the clamp.
b. The Securing Region
Generally, the securing region of a clamp has needle attachment regions and regions with alignment and locking mechanisms. Typically, the needle attachment regions are in close proximity to the regions of alignment and locking mechanisms.
In some embodiments, the securing region of a clamp is divided along the longitudinal plane A of the splittable needle assembly into two unequal parts: a protruding part and a recess part. In other embodiments, the securing region is divided along the longitudinal plane of the splittable needle assembly into equal parts. In preferred embodiments, the securing region is divided into a protruding part and a recess part, which are continuations of the symmetric clamp handles of the flexing region. The protruding part fits into, and optionally, locks into, the recess part. Together, the protruding part and the recess part are the structures forming the alignment mechanism and the locking mechanism of the securing region.
i. Needle Attachment Regions
Generally, each of the two parts of the securing region has a needle attachment region. Typically, the needle attachment region is located at about the center of each of the parts. However, in some embodiments, the needle attachment region may be located off-center, or close to outer edges of each of the parts of the securing region. In preferred embodiments, the needle attachment region is located at about the center of each of the parts of the securing region.
Generally, the needle attachment region can have any shape that matches and mates with the outer surface of the needle part of the splittable needle. Typically, the needle attachment region is concave. In preferred embodiments, the concave needle attachment region has an outer surface that mates with the convex outer surface of the needle part of the splittable needle. In preferred embodiments, each of the two needle parts of the splittable needle mates with the concave needle attachment regions of each of the two parts of the securing regions.
At the needle attachment regions, the radius of the clamp securing region is less than the radius of a designated needle, to allow the needle walls to meet.
The parts of the needle can be attached to the parts of the securing region of the clamp using any suitable means. In some embodiments, the attachment is achieved through chemical means, such as biocompatible adhesives or glues. In other embodiments, the attachment is achieved through physical bonding, such as ultrasonic welding. The selection of suitable means of attachment is based on the nature of materials forming the needle parts and the clamp parts.
ii. Alignment Mechanism
In some embodiments, the protruding part of the securing region has protrusions and edges running on its surface along the length of the clamp and along the longitudinal plane A. Typically, the recess part of the securing region has recesses and notches running its surface along the length of the clamp along the longitudinal plane A. Any number of protrusions, edges, recesses and notches can be present. In a preferred embodiment, the protruding part has one protrusion and no edge, and the recess part has at least one recess and one notch. During assembly, the protrusions of one part of the splittable needle align with and fit into the recesses of the other part of the splittable needle, providing for precise alignment. Therefore, in preferred embodiments, the protrusions and recesses allow one part of the splittable needle to precisely align with the other part of the needle along the entire needle length, eliminating potential misalignments that may lead to tissue injury, or leakage of fluids into or out of the needle.
In some embodiments, the protruding part and the recess part run only ½, ⅓, ¼, ⅕, ⅙, 1/7, ⅛, 1/9, or 1/10 of the length of the clamp along its longitudinal plane. In preferred embodiments, the protruding part and the recess part run along the entire length of the clamp along its longitudinal plane.
iii. Locking Mechanism
In some embodiments, the protrusions may carry extending edges, and the recesses may include notches. The edges are configured to securely fit and lock into the notches. Any number of edges per protrusion and any matching number of notches per recess may be present as long as an effective locking is achieved.
During assembly, the two needle parts are brought close together so that the edges fit into and lock in the notches, activating the securing region's locking mechanism, while simultaneously aligning the protrusions with recesses, and activating the aligning mechanism of the securing region. Assembled in this way, any misalignment, as well as any independent movement of one needle part relative to another are prevented until the two parts are split apart.
iv. Additional Elements
The securing region may have additional elements, such as covers, coatings, appendages, or limbs. The additional elements may be added to enhance the securement function of the securing region, or to provide adapters that will aid with holding, handling, and maneuvering of the clamp and the splittable needle assembly.
In a preferred embodiment, the splittable needle assembly is formed of a splittable needle, a clamp and a locking hub.
The locking hub 300 is positioned at the rear end R of the splittable needle assembly 1000. The locking hub 300 is formed of a locking neck region 320 and a locking tip region 340 that precedes the locking neck region 320. The locking tip region 340 has a first locking tip 341 and a second locking tip 342 that come together along the longitudinal axis X of the splittable needle assembly to form the locking tip region 340. The locking neck region 320 has a first locking neck 321 and a second locking neck 322 at the rear end R that come together along the longitudinal axis X of the splittable needle assembly 1000. The first locking neck 321 extends into a first locking tip 341, and the second locking neck 322 extends into a second locking tip 342 towards the front end F of the splittable needle 200.
Referring now to
Referring now to
The securing region 180 is formed of a first semi-circular ending 112 of the first clamp handle 110 and of a second semi-circular ending 122 of a second clamp handle 120. The first semi-circular ending 112 has a first outer surface 114 and the second semi-circular ending 122 has a second outer surface 124.
The semi-circular ending 112 has a center region for attaching to the first needle part 210—the first needle attachment region 151. The semi-circular ending 122 has a center region for attaching to the second needle part 220—the second needle attachment region 152.
At the needle attachment regions 151 and 152, the radius of the clamp securing region is less than the radius of a designated needle, to allow the edges of the needle parts to meet (see
The securing region 180 also has an alignment mechanism 160 for aligning the first needle part 210 and the second needle part 220 and locking the parts in place. In preferred embodiments, the alignment mechanism 160 is positioned in close proximity to the first needle part 210 and a second needle part 220 along the longitudinal axis A of the needle assembly 1000.
Referring now to
Other embodiments of the alignment mechanism are presented in
Referring now to
A list of referenced numbers with corresponding labels is presented in Table 2.
Kits containing plurality of individually wrapped and sterilized splittable needles and instructions for use are also provided. Optionally, the kits may include sterilized and packaged guidewires and PICC and/or Midline catheters. In preferred embodiments, the kits contain a plurality of individually wrapped and sterilized splittable needles of various sizes.
The splittable needles described herein are suitable for use in cardiac catheterization through peripherally located blood vessels. The splittable needles are assembled by aligning and simultaneously locking the two or more parts of the splittable needles.
The aligning and locking is achieved by aligning the one or more protrusions of one needle part with one or more notches of the other needle part and pressing on the parts to insert the protrusion(s) into the notch(es). Once inserted, the needle parts are assembled into a splittable needle, with the parts precisely aligned for ease of insertion into tissue and for minimizing leakages from areas of contact.
The splittable needle assembly is then inserted into a body lumen of a subject in need thereof. The body lumen is typically any vein or artery.
The splittable needle is inserted so that the rear end remains outside of the body and accessible by clinicians. A guidewire is then threaded through the needle. The guidewire is first entered into the funnel region in the rear end of the needle, then threaded through the needle and through the beveled tip into the vessel.
After the guidewire is placed inside the vessel, the splittable needle assembly is retracted. Following retraction, the tip at the front end of the needle is no longer inside the vessel, but the needle is still threaded through the guidewire. The splittable needle is ready to be split and removed from the guidewire.
The splittable needle is split by pressing on the radially protruding clamp handles of the flexing region to bring the clamp handles closer together. This motion allows the clamp handles to come towards while simultaneously pulling apart the securing regions. As the securing regions are pulled apart, they in turn pull away the protrusion(s) from the notch(es). This motion therefore separates one longitudinal needle part from the other, splitting the needle into individual parts that it can be removed from the guidewire.
1. Cardiac Catheterization
During vascular access for cardiac catheterization, the first step is to use an “introducer” needle to access the blood vessel. The next step is to introduce the guidewire, followed by catheter insertion. The introducer needle is removed after the guidewire is inserted. In most of the cardiac catheterization procedures, the guidewires are around six feet long, and the needle has to be retracted along the entire length of the guidewire before continuing the catheterization procedure. The needle described herein avoids this retraction step by “opening” along its length, so that the needle can be removed immediately after the guidewire is inserted into the blood vessel thereby improving the efficiency and safety of the procedure.
2. Percutaneous Coronary Intervention
Angioplasty, also called percutaneous coronary intervention (PCI), is a procedure used to open blocked coronary arteries (caused by coronary artery disease) and restore blood flow to the heart muscle without open-heart surgery.
For angioplasty, a special catheter (a long, thin, hollow tube) is inserted into a blood vessel and guided to the blocked coronary artery over a guidewire which is either 190 or 300 cm long. The guidewire has a very sensitive tip which is either custom-shaped or pre-shaped. It is introduced into the catheter via a blunt needle introducer. The catheter has a tiny balloon at its tip. Once the catheter is in place, the balloon is inflated at the narrowed area of the coronary artery. This presses the fatty tissue against the sides of the artery making more room for blood flow.
The splittable needles described herein can aid in insertion of the catheter into the blood vessel during PCI by allowing the blunt needle to be removed from the wire without needing to pull through its whole length by splitting.
3. Biopsy
The splittable needles described herein can have applications in diverse biopsy procedures. Biopsies accessing hard-to-reach tissues require inserting into patient's body and guiding long flexible wire-like instruments, such as laparoscopes and bioptomes, to a desired tissue site using x-ray or ultrasound guidance. Splittable needles may aid in inserting of the instruments at a particular location in the body, and then can be removed by retracting the needle from the body and splitting it into two parts to separate the needle from the instrument.
For example, endomyocardial biopsies require insertion and guidance of bioptomes from blood vessels to the heart for sampling of cardiac tissue following cardiac transplantation (Kilo et al., Multimedia Manual of Cardiothoratic Surgery, doi:10.1510/mmcts.2005.001149 (2006)). The splittable needles could be used for placement of the bioptomes in the desired blood vessel.
Liver biopsies require insertion into tissue and guidance of long needles to the liver. The splittable needles can be used to insert and position the biopsy needle, but then be retracted and removed from the biopsy needle following collection of a liver sample.
Splittable needles can also be useful for guiding needle biopsies into soft tissues e.g. breast. The splittable needles can precisely guide the biopsy needles into tissues of interest and then be retracted and split away from the biopsy needle.
Using ultrasonographic guidance, vascular access was obtained in a pig's femoral artery using the splittable needle. A 180 cm 0.035-inch diameter guidewire was placed in the common femoral artery and the needle was successfully removed over the wire using the splittable technique instead of withdrawing over the whole wire.
This application claims benefit of U.S. Provisional Application No. 61/969,287, filed Mar. 24, 2014, which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US15/22207 | 3/24/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61969287 | Mar 2014 | US |
