Flexible inflow/outflow cannula

• US 5,527,276 A
• Filed: 05/13/1994
• Issued: 06/18/1996
• Est. Priority Date: 01/12/1993
• Status: Expired due to Term

• Current Assignee: Cannuflow Inc.
• Original Assignee: Arthroscopic Assistants, Inc.
• Inventors: Bruce, Robert P.
• Primary Examiner(s): MCDERMOTT, CORRINE MARIE
• Application Number:
  US08/242,703
• Time in Patent Office: 767 Days
• Field of Search: 604/54, 604/164, 604/264, 604/280, 433/91
• US Class Current: 604/506
• CPC Class Codes: A61B 17/3415 for introducing tubes or catheters, e.g. gastrostomy tubes, drain catheters A61B17/3417 takes precedence; body piercing catheter guide needles A61M25/06
• CPC Class Codes: 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
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked

Abstract

A flexible plastic cannula for use in directing liquid to or from the suprapatellar pouch during arthroscopic knee surgery. The cannula is comprised of a flexible elongated stem, a valve housing and an attachment means, all molded in a single piece of high density polyethylene. The stem is tapered along its length so that the end nearest the valve housing is relatively rigid, while the distal end is narrower and more flexible. The flexibility of the cannula stem is sufficient to allow it to bend with the knee during the arthroscopic surgery.

Claims

1. A method for directing a liquid to or from a site during arthroscopic knee surgery comprising the steps of:

a) inserting a cannula/trocar assembly into the suprapatellar pouch of a human knee, the cannula comprising an elongated hollow stem having a flexible segment that includes a distal end of the cannula, and wherein the flexible segment is sufficiently flexible to bend through an angle of approximately ninety degrees and then return to an approximately straight position;

b) removing the trocar from the cannula; and

c) allowing a liquid to flow through the cannula.

2. The method of claim 1 wherein a first outer diameter of the flexible segment, measured at a proximal end of the flexible segment, is greater than a second outer diameter of the flexible segment, measured at the distal end of the cannula.

3. The method of claim 1 wherein a first thickness of the flexible segment, measured at a proximal end of the flexible segment, is greater than a second thickness of the flexible segment, measured at the distal end of the cannula.

4. The method of claim 1 wherein the flexible segment is comprised of high density polyethylene.