Coagulating cannula

• US 5,290,282 A
• Filed: 06/26/1992
• Issued: 03/01/1994
• Est. Priority Date: 06/26/1992
• Status: Expired due to Term

• Current Assignee: Christopher D. Casscells
• Original Assignee: Christopher D. Casscells
• Inventors: Casscells, Christopher D.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): Bockelman, Mark
• Application Number:
  US07/905,907
• Time in Patent Office: 613 Days
• Field of Search: 606/37, 606/49, 606/39, 606/40, 606/41, 606/45, 606/32, 606/28, 606/29, 604/164, 604/20-22, 604/264, 604/280, 604/283
• US Class Current: 606/29
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy

Abstract

A coagulating cannula is described which effectively operates in a localized area quite rapidly, without the need for removal of motorized shaving instruments, by the incorporation of a selective manually operative electrocautery positioned at a distal end of the shaft of the cannula. The cannula incorporates a nonconductive cylindrical hollow shaft and a nonconductive hub portion through which the motorized shaving instruments are inserted and removed. The electrocautery component enters the cannula at an electrical contact which protrudes from an outer surface of the hub portion and continuously runs within the hub and into a wall of the shaft terminating at the distal end of the shaft in a prominance at the tip of the shaft. The prominance is of a small surface area such that the prominance provides a small electrical contact area with a surrounding saline environment, thereby providing a high resistance arcing to the surrounding tissue that needs to be coagulated.

Claims

1. A coagulating cannula which comprises:

(a) a nonconductive cylindrical hollow shaft having a proximal and a distal end, the distal end terminating in a tapered tip, the tapered tip having one straight side along a longitudinal axis of the shaft and an opposed shortened side with a tapered region extending from the shortened side to the straight side, the shaft being dimensioned to receive shaving or deburring instruments;

(b) a nonconductive hub portion securely attached to the proximal end of the shaft at a receiving base having a first opening of a diameter which is similar to a diameter of the hollow shaft and communicates with the hollow shaft, the hub portion additionally having a larger second opening on an opposed exiting hub surface to the shaft, the second opening continuously communicating with the first opening; and

(c) an electrocautery which is manually operable by selectively activating an electrocautery circuit which enters the cannula at an electrical contact which protrudes from an outer surface of the hub portion and continuously runs within the hub and into a wall of the shaft terminating at the distal end of the shaft in a prominence at a tip of the straight side of the tapered tip of the shaft, the prominance having a small surface area on the tapered tip, such that the prominance provides a small electrical contact area with a surrounding saline environment, thereby providing a high resistance arcing to the surrounding tissue that needs to be coagulated.

2. The cannula of claim 1 wherein the non-conductive shaft and non-conductive hub are an FDA-approved polymer for insertion into a human.

3. The cannula of claim 2 wherein the polymer is a nylon.

4. The cannula of claim 3 wherein the polymer is a nylon-6,6.

5. The cannula of claim 1 wherein the prominance has a small surface area such that the prominance provides a small electrical contact area with a surrounding saline environment, thereby providing a high resistance arcing to the surrounding tissue that needs to be coagulated.