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

• Current Assignee: Edwin L. Adair
• Original Assignee: Edwin L. Adair
• Inventors: Adair, Edwin L.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US07/954,655
• Time in Patent Office: 496 Days
• Field of Search: 604/51, 604/158, 604/164-171, 604/96, 604/272, 604/273, 604/274, 606/185, 128/753, 128/754
• US Class Current: 604/164.12
• CPC Class Codes: A61B 17/3474 Insufflating needles, e.g. Veress needles
• CPC Class Codes: A61B 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612

Abstract

In accordance with this invention a disposable trochar for use as a gas insufflation needle is provided for insertion through the abdominal wall of a patient and into a body cavity. It has an outer sheath with a tubular body, a distal open end and a proximate open end. The distal end may have means which is expandable after the trochar has been inserted into the body cavity to minimize dislocation of the outer sheath during use. A cannula is removably received within in the sheath which has a sharp distal end extendable beyond the distal end of the sheath and an enlarged head at the proximate end of the cannula. The head has a flat land which is engageable with the proximate end of the sheath to limit the extension of the distal end of the cannula beyond the distal end of the sheath. A rod is mounted within the cannula for longitudinal movement between a retracted position and an extended position. A blunt member is provided at the distal end of the rod extending beyond the sharp distal end of the cannula when in extended position. A spring, in a cavity in the head, is attached to the proximate end of the rod urging it toward the extended position. The method of using the trochar is also disclosed.

Claims

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.

2. Apparatus, as claimed in claim 1, further including:

an extendable member adjacent said distal end of said sheath for holding said distal end of said sheath in place in the body cavity.

3. Apparatus, as claimed in claim 1, wherein:

said distal end of said rod is formed as two wire loops which lie in substantially perpendicular planes.

4. The apparatus as in claim 1, further including:

a cylindrical insert selectively positioned in said proximate end of said central passageway having an inside diameter to size said proximate end of said central passageway to receive an instrument of smaller diameter than said cannula and having an outside diameter substantially the same as said inside diameter of said insert.

5. 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 on 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 blunt distal end, said blunt 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;

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 form said sheath to minimize escape of the CO₂ gas therethrough.

6. Apparatus, as claimed in claim 5, further including:

an extendable member adjacent said distal end of said sheath for holding said distal end of said sheath in place in the body cavity.

7. The apparatus as in claim 5, further including a cylindrical insert selectively positioned in said proximate end of said central passageway having an inside diameter to size said proximate end of said central passageway to receive an instrument of smaller diameter than said cannula and having an outside diameter substantially the same as said inside diameter of said insert.