# US 9,750,532 B2 · Access needles and stylet assemblies

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- Number: US 9,750,532 B2
- Document ID: US9750532B2
- Status: Granted
- Kind: B2
- Application number: 14/277,496
- Filed: 2014-05-14
- Published: 2014-12-04
- Granted: 2017-09-05
- Earliest claimed: 2013-05-31
- Assignees: Cook Medical Technologies LLC
- Applicants: Cook Medical Technologies LLC
- Inventors: Ciarán Toomey; Michael Dunning; Fionan Keady
- Web page: https://patentgrep.com/patent/US9750532B2

## CPC

- A61B 17/3478: {Endoscopic needles, e.g. for infusion (biopsy needles A61B10/0233; catheters with injection needles A61M25/0067)}
- A61B 1/018: for receiving instruments
- A61B 6/12: Arrangements for detecting or locating foreign bodies
- A61B 8/0841: {for locating instruments}
- A61B 8/481: {involving the use of contrast agents, e.g. microbubbles introduced into the bloodstream}
- A61B 17/00234: {for minimally invasive surgery (A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence)}
- A61B 17/3417: {Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating (syringe needles A61M5/32; dilators A61M29/00)}
- A61B 10/0233: {Pointed or sharp biopsy instruments}
- A61B 17/3403: {Needle locating or guiding means}
- A61B 2010/045: {Needles (pointed biopsy devices with vacuum aspiration A61B10/0283)}
- A61B 2017/00292: {mounted on or guided by flexible, e.g. catheter-like, means}
- A61B 2017/00336: {with a protective sleeve, e.g. retractable or slidable}
- A61B 2017/0034: {adapted to be inserted through a working channel of an endoscope}
- A61B 2017/3413: {guided by ultrasound}
- A61B 2090/3925: {ultrasonic}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

Access needles and methods of using the needles are set forth in this disclosure. The needles can include a handle and a cannula having a proximal end operatively connected to the handle, a distal end, and a lumen extending through the body of the cannula. A protective sheath may surround the cannula. Further, a stylet may be removably disposed within the lumen of the cannula. The stylet includes a piercing tip at a distal end and a flexible body length extending proximally from the piercing tip to the handle. The flexible body of the stylet provides a path of fluid communication through the lumen of the cannula such that a contrast fluid can effectively pass through the lumen of the cannula. Methods of introducing cannulas to target locations within a body of a patient are also set forth in this disclosure.

## Claims

### Claim 1

An access needle comprising:
an elongate hollow cannula having a proximal end, a distal end, and a lumen extending therebetween; and
a stylet removably disposed within the lumen of the cannula, the stylet comprising:
a hollow piercing tip disposed at a distal end of the stylet; and
a flexible body length comprising a plurality of wire strands, said wire strands contacting each other and being oriented both generally parallel with each other and with a central longitudinal axis of the stylet extending proximally from the piercing tip toward the proximal end, whereby an outer boundary of the flexible body of the stylet is sized to an inner diameter of the lumen of the cannula but the flexible body occupies less than an entire cross-sectional volume of the lumen and thereby provides a path of fluid communication through the entire lumen of the cannula such that a contrast fluid can effectively pass through the lumen of the cannula in contact with the cannula lumen, longitudinally between and around wire strands of the stylet, and through an inside of the hollow piercing tip while the stylet is disposed within the lumen of the cannula and contacts an inward-facing surface of the cannula that defines the lumen of the cannula between the proximal end and the distal end of the cannula.

### Claim 2 (depends on 1)

The access needle of claim 1, wherein the stylet comprises a coiled wire.

### Claim 3 (depends on 1)

The access needle of claim 1, wherein the plurality of wire strands comprises three wire strands each of which contacts the other two strands, and further wherein the outer boundary sized to the inner diameter of the lumen of the cannula provides said outer boundary maintaining longitudinal contact with the inner diameter of the lumen of the cannula.

### Claim 4 (depends on 3)

The access needle of claim 3, wherein the three wire strands are joined together along the body of the stylet in one or more locations.

### Claim 5 (depends on 1)

The access needle of claim 1, wherein the hollow piercing tip comprises stainless steel.

### Claim 6 (depends on 1)

The access needle of claim 1, wherein a distal end of each wire strand comprising the plurality of wire strands is connected in direct contact with a proximal end of the piercing tip.

### Claim 7 (depends on 1)

The access needle of claim 1, wherein the plurality of wire strands is joined together along the body of the stylet in one or more locations.

### Claim 8 (depends on 1)

The access needle of claim 1, wherein the distal end of the elongate hollow cannula comprises a dimpled surface configured to enhance echogenicity.

### Claim 9 (depends on 1)

A method of introducing a cannula to a target location within a body of a patient through an endoscope comprising:
loading the distal end of the access needle of claim 1 into a lumen of the endoscope;
puncturing the distal end of the access needle into the target location;
directing contrast fluid to flow through the cannula lumen and exit the distal end of the cannula through and/or around the stylet while the stylet is disposed within the lumen and is contacting an inward-facing lumen surface of the cannula between the proximal end and the distal end of the access needle;
fluoroscopically visualizing the body of the patient to determine a location of the contrast fluid;
confirming by the location of the contrast fluid that the distal end of the cannula is at the target location;
withdrawing the stylet; and
leaving the cannula in place with the distal end of the cannula at the target location.

### Claim 10 (depends on 9)

The method of claim 9, further comprising steps of connecting a syringe to the handle of the access needle and aspirating fluid from the target location.

### Claim 11 (depends on 9)

The method of claim 9, further comprising a step of passing a wire guide through the cannula lumen into the target location.

### Claim 12 (depends on 11)

The method of claim 11, further comprising steps of retracting the handle of the access needle, withdrawing the needle into the sheath, and removing the access needle from the endoscope, thereby leaving the wire guide in place for further access to the target location.

### Claim 13 (depends on 9)

The method of claim 9, wherein the stylet comprises a coiled wire.

### Claim 14 (depends on 9)

The method of claim 9, wherein the plurality of wire strands comprises three wire strands each of which contacts the other two strands, and further wherein the outer boundary sized to the inner diameter of the lumen of the cannula provides said outer boundary maintaining longitudinal contact with the inner diameter of the lumen of the cannula.

### Claim 15 (depends on 14)

The method of claim 14, wherein each of the plurality of wire strands is joined together with other(s) of the plurality of wire strands along the body of the stylet.

### Claim 16 (depends on 14)

The method of claim 14, wherein a distal end of each wire strand comprising the plurality of wire strands in direct contact with a proximal end of the piercing tip.

### Claim 17

An access needle comprising:
an elongate hollow cannula having a proximal end, a distal end, and a lumen extending therebetween; and
a stylet removably disposed within the lumen of the cannula, the stylet comprising:
a hollow piercing tip at a distal end of the stylet; and
a flexible body length extending proximally from the piercing tip toward the proximal end, whereby the flexible body of the stylet comprises a plurality of wires generally longitudinally parallel with each other and with a central longitudinal axis, which stylet provides a path of fluid communication through the entire lumen of the cannula such that a contrast fluid can effectively pass through the lumen of the cannula between the wires and through the hollow piercing tip while the stylet is disposed within the lumen between the proximal end and the distal end and contacts an inward-facing surface of the cannula defining the lumen, wherein a distal end of each wire is connected in direct contact with a proximal end of the hollow piercing tip.

### Claim 18 (depends on 17)

The access needle of claim 17, wherein the plurality of wires comprises three wire strands that are joined together periodically along the flexible body length of the stylet and further wherein the hollow piercing tip is beveled and comprises stainless steel.