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Trochar system for laparoscopy

  • US 5,284,474 A
  • Filed: 09/30/1992
  • Issued: 02/08/1994
  • Est. Priority Date: 12/11/1990
  • Status: Expired due to Fees
First Claim
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1. A disposable trochar in the form of a gas insufflation needle for insertion through an abdominal wall into a body cavity for the simultaneous introduction of CO2 gas and medical instruments into the body cavity for diagnosis and/or treatment, said trochar comprising:

  • a rigid cannula having a first outside diameter, a cutting edge of the distal end thereof for cutting through the abdominal wall and an enlarged head at the proximate end having a cavity therein in communication with said cannula;

    a coil spring mounted in said cavity;

    a rod mounted for longitudinal movement between a retracted position and an extended position within said cannula, said rod having a proximate end formed integrally with said spring and a distal end, said distal end being received within said distal end of said cannula when said rod is in said retracted position and extending beyond said distal end of said cannula when said rod is in said extended position and having an integral loop formed at said distal end of said rod;

    an outer sheath having a tubular body with a proximate end and a distal end for receiving said cannula and having a length less than that of said cannula so that said distal end of said cannula extends beyond said distal end of said sheath, said outer sheath having a second inside diameter sufficiently greater than said first outside diameter of said cannula to allow passage of CO2 gas therearound;

    an inlet port through said sheath at said proximate end thereof to introduce CO2 gas through said sheath and around said cannula to the body cavity to expand it with said cannula in place within said sheath; and

    a spring biased closure within said sheath between said inlet port and said proximate end of said sheath to close said proximate end thereof when said cannula is withdrawn from said sheath to minimize escape of the CO2 gas therethrough.

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