Self protecting knife for curved jaw surgical instruments

• US 5,797,938 A
• Filed: 11/18/1996
• Issued: 08/25/1998
• Est. Priority Date: 10/20/1995
• Status: Expired due to Term

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Paraschac, Joseph F., Nobis, Rudolph H., Wales, Kenneth S., Rupp, Kip
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): SHAI, DAPHNA
• Application Number:
  US08/751,898
• Time in Patent Office: 645 Days
• Field of Search: 606/37, 606/41, 606/51, 606/52, 227/180
• US Class Current: 606/167
• CPC Class Codes: A61B 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 17/320016 Endoscopic cutting instruments, e.g. arthroscopes, resectoscopes A61B10/0233, A61B17/29, A61B17/3207 take precedence
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 18/1447 wherein sliding surfaces cause opening/closing of the end effectors
• CPC Class Codes: A61B 2017/2945 Curved jaws
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1432 curved

Abstract

An electrosurgical hemostatic instrument including a curved end effector. A preferred embodiment of the invention provides a bipolar endoscopic clamping, coagulation and cutting device. In this device, a substantially straight, axially flexible knife is used to cut tissue grasped by the jaws of the end effector. The end effector includes a knife channel which is wider than the knife. The knife may include sacrificial contact points adapted to contact the walls of the knife channel as the knife moves through the channel, protecting the cutting edges of the knife blade from damage.

Claims

1. A surgical instrument including an end effector wherein said end effector comprises:

first and second curved jaw members adapted to grasp tissue wherein said jaw members are curved along a proximal to distal axis of said instrument;

a curved knife channel within said jaw members wherein said knife channel is at least three times as wide as said knife;

an axially flexible knife adapted to move through said end effector from said proximal end to said distal end of said end effector wherein said knife includes a cutting edge at a distal end thereof, said cutting edge including at least one sacrificial contact point wherein said sacrificial contact point contacts said knife channel over a portion of its travel.

2. A surgical instrument according to claim 1 wherein at least a portion of said knife blade is angled in a distal to proximal direction such that said distal end of said cutting edge comprises said sacrificial contact point.

3. A surgical instrument according to claim 1 wherein said cutting edge includes a plurality of angled sections such that said cutting edge includes a plurality of sacrificial contact points at said distal end of said blade.

4. A surgical instrument according to claim 1 wherein said distal end of said knife contacts an interior wall of said end effector to form an angle between said interior wall and said knife blade.

5. A surgical instrument according to claim 1 wherein said distal end of said knife contacts said first interior wall of said knife channel at a first angle greater than five degrees and a second interior wall of said knife channel at a second angle greater than five degrees.

6. A surgical instrument comprising:

a proximal end including a handle;

a distal end including a curved end effector said end effector comprising;

a knife channel; and

jaws adapted to grasp tissue;

a knife adapted to move through said knife channel wherein said knife channel is at least 3 times as wide as said knife, wherein said knife comprises;

a shaft adapted to flex in the direction of curvature of said end effector; and

a sharpened cutting edge at the distal end of said knife and a plurality of sacrificial points positioned to contact at least one interior wall of said knife channel as said knife moves through said channel.

7. A method of cutting tissue grasped between the jaws of a curved end effector using a substantially straight, axially flexible knife said method comprising the steps of:

a) moving said axially flexible knife through a first portion of said end effector until said knife contacts a first concave wall of said end effector at an interior angle greater than five degrees, said first wall forcing said knife to bend in a first direction toward a second convex wall of said knife channel;

b) moving said knife past said first wall, through said knife channel until said knife contacts said second wall at an interior angle greater than five degrees, said second wall bending said knife in a second direction substantially parallel to said second wall; and

c) moving said knife along said second wall.