Adjustable Stepped Cannula

Patent metadata

Field	Value
Publication number	US-2018289393-A1
Application number	US-201515525548-A
Country	US
Kind code	A1
Filing date	Nov 12, 2015
Priority date	Nov 13, 2014
Publication date	Oct 11, 2018
Grant date	—

Abstract

The use of stepped cannulas, wherein a step structure creates a backstop to reduce backflow along the cannula body, is known for convection enhanced delivery of agents to the brain and other structures within an animal. Described herein are novel and improved stepped cannula designs wherein the length of the cannula segment between the step and the dispensing outlet is variable and can be controllably adjusted inside the patient during delivery. This advantageously allows the operator to place the cannula step at the optimal position and deliver agents at one or more positions within the target structure.

First claim

1 . A cannula for convection-enhanced delivery of a solution to a target area within the body of an animal comprising,
an elongated body having a proximal end, a distal end, and a central lumen which extends from the proximal to the distal end of the body; a telescoping element which is enclosed within the central lumen of the body; wherein a portion of such telescoping element protrudes from the distal end of the body; wherein the length of the telescoping portion protruding from the distal end of the body is adjustable by movement of the telescoping element within the body in the proximal or distal direction; wherein a portion of the telescoping body protrudes from the proximal end of the body; and wherein the telescoping portion comprises a continuous lumen with openings at the proximal and distal end; and wherein the width of the telescoping element is less than that of the body, such that a step is formed at the distal end of the body around the protruding portion of the telescoping element.

2 . (canceled)

3 . (canceled)

4 . The cannula of claim 1 , further comprising
a locking mechanism that, when engaged, holds the telescoping element in a fixed position with the body.

5 .- 7 . (canceled)

8 . The cannula of claim 1 , further comprising
a minor step, the minor step being an abrupt reduction in the width of the telescoping element, wherein the distal end of the telescoping element is narrower than the proximal end.

9 . The cannula of claim 1 , further comprising
a visual indicator disposed at or near the proximal end of the cannula which allows the operator to determine the length of the portion of the telescoping element which protrudes from distal end of the body.

10 .- 12 (canceled)

13 . The cannula of claim 1 , wherein the telescoping element comprises ceramic and the lumen of the telescoping element comprises fused silica or polymer.

14 .- 17 . (canceled)

18 . The cannula of claim 1 , wherein
the portion of the telescoping element which protrudes from the distal end of the body has a length that can be adjusted between 1 and 40 mm.

19 . The cannula of claim 1 , wherein
the step formed at the distal end of the body has a width of 0 . 1 - 2 mm.

20 . A method of performing convection-enhanced delivery of a solution to a target structure within an animal, comprising the steps of introducing an adjustable stepped cannula into the body of the animal, such introduction being guided by external radiographic imaging of the distal end of the cannula, and such adjustable stepped cannula comprising
an elongated body having a proximal end, a distal end, and a central lumen which extends from the proximal to the distal end of the body; a telescoping element which is enclosed within the central lumen of the body; wherein a portion of such telescoping element protrudes from the distal end of the body; wherein the length of the telescoping portion protruding from the distal end of the body is adjustable by movement of the telescoping element within the body in the proximal or distal direction; wherein a portion of the telescoping body protrudes from the proximal end of the body; and wherein the telescoping portion comprises a continuous lumen with openings at the proximal and distal end; wherein the width of the telescoping element is less than that of the body, such that a step is formed at the distal end of the body around the protruding portion of the telescoping element; and wherein the proximal lumen of the telescoping element is connected to a supply of the solution; positioning the adjustable stepped cannula such that the step is located at or near the boundary or opening of the target structure, such positioning being enabled by external radiographic imaging of the step; moving the telescoping element such that the distal opening of the lumen within the telescoping element is positioned in a desired placement within the target structure, such positioning being enabled by external radiographic imaging of the distal end of the inner tube; and engaging the supply of solution such that solution flows into the distal end of the lumen of the telescoping element and exits the distal end of the lumen of the telescoping element, into the target structure.

21 . The method of claim 20 , wherein
solution is dispensed from the distal end of the telescoping element wherein the distal end of the telescoping element is in a first position within the body; the telescoping element is subsequently moved in the distal direction to a second position within the body, such that the length between the distal end of the telescoping element and the distal end of the body is increased; and solution is then dispensed from the distal end of the telescoping element while it is in such second position.

22 . The method of claim 20 , wherein
solution is dispensed from the distal end of the telescoping element wherein the distal end of the telescoping element is in a first position within the body; the telescoping element is subsequently moved in the proximal direction to a second position within the body, such that the length between the distal end of the telescoping element and the distal end of the body is decreased; and solution is then dispensed from the distal end of the telescoping element while it is in such second position.

23 . The method of claim 20 , wherein
the target structure is in the brain.

24 . The method of claim 23 , wherein
the target structure is selected from the group consisting of the putamen, the caudate nucleus, dorsal raphe, locus ceruleus, brain stem, thalamus, and hippocampus.

25 . The method of claim 20 , wherein
the animal is a human patient.

26 . The method of claim 20 , wherein
the solution comprises a therapeutic agent.

27 . The method of claim 26 , wherein
the therapeutic agent comprises a drug, a protein, or a nucleic acid construct.

28 . The method of claim 20 , wherein
the solution comprises an imaging agent.

29 . The method of claim 28 , wherein
the imaging agent is gadolinium.

30 . A method of delivering a solution to a target structure within the brain, comprising:
positioning an adjustable stepped cannula comprising a major step, an adjustable tip, and a controllably delivered supply of solution, such that the major step of the cannula is located at the boundary or opening of the target structure, wherein the adjustable tip is in a retracted position; subsequently extending the adjustable tip to a series of two or more subsequent positions, wherein solution is dispensed at each of the two or more subsequent positions.

Assignees

• Univ California

Inventors

• Bankiewicz Krystof

Classifications

• A61M5/3286

  Needle tip design, e.g. for improved penetration · CPC title

• A61M5/158 Primary

  Needles {for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body} · CPC title

• A61B2017/00991

  Telescopic means · CPC title

• A61M5/46

  having means for controlling depth of insertion · CPC title

• A61M2210/0693

  Brain, cerebrum · CPC title