Trocar instrument

Claim 2

An instrument according to claim 1, wherein the insulating means is an insulating sleeve or coating (28A,104A) disposed on the inside of the trocar sleeve (28,104).

Claim 3

An instrument according to claim 1, wherein the insulating means is a sleeve or coating (312A) disposed on the outside of the trocar sleeve (313).

Claim 4

An instrument according to claim 3, wherein the sleeve or coating (312A) is elastomeric.

Claim 5

An instrument according to claim 1, wherein the sleeve comprises a first sleeve (313) surrounded by a second sleeve (312) which is provided with the radially expandable portion, and wherein the means capable of expanding the portion comprise a first gear member (319) on the second sleeve (312) including first interengagable means (320) extending along the second sleeve; and a second gear member (321A) being carried on a housing (311) having second interengagable means (321) for companion interfacing with the first interengagable means and being rotatable about an axis transversely to the axis of the first and second sleeves (312,313), to move the radially expandable portion (20,90,92,323) into an expanded position.

Claim 6

An instrument according to claim 1, wherein the trocar sleeve comprises a first sleeve (313) surrounded by a second sleeve (312) which is provided with the radially expandable portion (323); wherein the insulating means is a sleeve or coating (313A) disposed between the first and second sleeves.

Claim 7

An instrument according to according to any one of the preceding claims, wherein the insulating means is formed of a conductive plastic having an electrical conductance of less than about 100 ohms per square inch, to dissipate charge from the trocar assembly during the insertion of the instrument.

Claim 8

A laparoscopic surgical method, comprising the steps of forming an incision through the abdominal wall of a patient; introducing through the incision a laparoscopic trocar assembly comprising a trocar sleeve (28,104 313) having a first end which, in use, extends into the abdomen through the incision in the abdominal wall, the first end of the sleeve having a first external dimension passage through the incision, a radially expandable portion (20,90,92,323) for expanding a portion of the first end of the sleeve within the abdomen, a passageway through the assembly and interior of the sleeve for introduction and removal of the laparoscopic instrument; insulation means (28A,104A,312A,313A) to electrically insulate the trocar assembly from an operator or the patient while the instrument is within the assembly; and expanding the first end of the sleeve within the abdomen to a larger, second external dimension, the first end of the sleeve abutting the inner abdominal wall about the incision when expanded to the second external dimension to resist the withdrawal of the trocar assembly from the abdominal cavity.

Claim 9

A method according to claim 8, further comprising the step of introducing an electrically activated laparoscopic instrument through the passageway and into the abdominal cavity.

Claim 10

A method according to claim 9, further comprising the steps of reducing the external dimension of the first end from the second external dimension to the first external dimension while the laparoscopic trocar sleeve is within the abdomen; and withdrawing the electrically activated laparoscopic instrument through the laparoscopic trocar assembly.

Claim 11

A method according to claim 9, further comprising the steps of withdrawing the electrically activated laparoscopic instrument from the abdomen out of the trocar assembly, and retracting the portion of the first end of the sleeve (28,104,313) within the abdomen so that the external dimension of the first end is retracted to the first external dimension prior to withdrawal of the assembly from the abdominal cavity.