Method for using a trocar for penetration and skin incision

• US 6,017,356 A
• Filed: 09/19/1997
• Issued: 01/25/2000
• Est. Priority Date: 09/19/1997
• Status: Expired due to Term

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Kelly, William D., Paraschac, Joseph F., Frederick, Christopher J., Schwemberger, Richard F., Measamer, John P.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US08/933,797
• Time in Patent Office: 858 Days
• Field of Search: 606/167, 606/170, 606/172, 606/185, 604/164, 604/264
• US Class Current: 606/185
• CPC Class Codes: A61B 17/3211 Surgical scalpels, knives; Accessories therefor
• 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 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612
• CPC Class Codes: A61B 2017/346 with wings

Abstract

A method for establishing a surgical port for endoscopic or arthroscopic surgery is disclosed. A trocar is initially provided, and the obturator of the trocar includes a flat cutting blade, a shield that moves proximally and distally from a precock position to an extended position, a precock lever to move the shield proximally to expose the flat cutting blade, and a shield retaining assembly to constrain the shield in the proximal position. "Precocking" the trocar of the present invention moves the shield from the distal position wherein the flat blade is covered, to a proximal position wherein the flat blade is exposed, and the shield is constrained by the shield retaining assembly. Once the flat cutting blade is exposed, the skin of the patient is incised with the flat cutting blade of the obturator. The flat blade of the trocar is inserted into the incision and a penetrating force is applied so that the flat blade penetrates into the internal body cavity of the patient. The obturator assembly is removed from the cannula assembly so that the surgical access port is provided into the internal body cavity of the patient. This method eliminates the need for a separate surgical sharp to initially incise the skin before penetration is effected.

Claims

1. A method for establishing a surgical port for an internal body cavity during endoscopic or arthroscopic surgery on a patient, said method comprising:

a) providing a trocar having an obturator assembly and a cannula assembly surrounding said obturator assembly, said obturator assembly capable of being inserted into and withdrawn from said cannula assembly, said obturator assembly having;

i) an obturator, said obturator including a flat cutting blade at a distal end of said obturator, said flat cutting blade having first and second planar surfaces generally parallel to each other, said planar surfaces converging to a cutting edge surface, and a handle at a proximal end of said obturator;

ii) a shield slidably mounted on said obturator, said shield movable from a precocked position wherein said shield is retracted so as to expose said flat cutting blade of said obturator, to an extended position wherein said shield covers said flat cutting blade, said shield having a shield retaining surface thereon and a precock surface thereon;

iii) a precock lever movable from an unactuated position wherein said shield is in the extended position to an actuated position wherein said shield is in the precocked position, said precock lever having a shield retraction surface cooperable with said precock surface of said shield for moving said shield from the extended position to the precocked position when said precock lever is moved from the unactuated position to the actuated position; and

iv) a shield retaining subassembly cooperable with said shield retaining surface of said shield, said shield retaining subassembly adapted to hold said shield in the precocked position when said precock lever has been moved from the unactuated position to the actuated position;

b) moving the precock lever from the unactuated position to the actuated position so as to expose said flat cutting blade of said obturator upon retraction of said shield from its extended position to its precock position;

c) incising the skin of the patient with said exposed flat cutting blade of said obturator;

d) applying a penetrating force against the incised skin with said exposed flat cutting blade of said obturator so as to gain entry of said trocar into the internal body cavity of the patient; and

e) removing said obturator assembly from said cannula assembly so as to provide the surgical port through the cannula assembly into the internal body cavity of the patient.

2. The method of claim 1 wherein said obturator is movable axially relative to said handle, said obturator is biased in the distal direction, and said obturator assembly has a shield deployment mechanism cooperable with said shield retaining subassembly, said shield deployment mechanism releasing said shield retaining subassembly from said shield retaining surface of said shield so as to allow movement of said shield from the precock position to the extended position when said obturator is moved proximally over an unlocking proximal distance.

3. The method of claim 2 wherein when the skin of the patient is incised, the proximal movement of said obturator does not exceed the unlocking proximal distance, said shield deployment mechanism is not released, and said flat cutting blade remains exposed with said shield in the prococked position.

4. The method of claim 2 wherein the skin of the patient is incised, the proximal movement of said obturator equals or exceeds the unlocking proximal distance, said shield deployment mechanism is released, and said shield moves from its precock position to is extended position so as to cover said flat cutting blade of said obturator.