Vascular tissue sealing pressure control and method

• US 6,179,834 B1
• Filed: 06/25/1998
• Issued: 01/30/2001
• Est. Priority Date: 09/19/1995
• Status: Expired due to Term

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Sherwood Services AG
• Inventors: Lands, Michael J., Lukianow, S. Wade, Ryan, Thomas P., Kennedy, Jenifer S., Loeffler, Donald R., Buysse, Steven P.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): ROLLINS, ROSILAND STACIE
• Application Number:
  US09/104,729
• Time in Patent Office: 950 Days
• Field of Search: 606/32, 606/38, 606/41, 606/42, 606/48, 606/50-52, 606/191, 606/213, 606/215, 606/216, 606/118, 606/151, 606/142, 606/143, 607/115, 607/116, 607/7
• US Class Current: 606/41
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive 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 2017/2932 Transmission of forces to jaw members
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 90/03 Automatic limiting or abutting means, e.g. for safety

Abstract

A clamping force mechanism and its method of use with electrosurgery allow a user to seal and/or join patient'"'"'s particular vascular tissue; the mechanism is elongate with user and patient ends. An actuator is at the user end and the effectors are at the patient end. Each effector has a face of an area to contact the particular vascular tissue. A lost motion connection transfers user actuation to the effectors to hold a predetermined clamping force during electrosurgical tissue sealing. A yielding member in the loss motion connection clamps the particular tissue between the faces with a predetermined force. The yielding member is a spring, slip clutch or hydraulic coupling possibly near the actuator. An active electrode is carried on one end effector and a return electrode contacts the tissue so an electrosurgical energy supply connected thereacross delivers energy therebetween. A feedback circuit responds to parameters of energy delivered to tissue. A temperature sensor on one face and an impedance monitor respond to energy delivered. A control applies energy to held tissue to seal and/or join it. The method transfers user actuation of the effectors with the lost motion connection, maintains clamping force while sealing and applying electrosurgical energy to seal and/or join held tissue. Energy is applied to a temperature or an impedance. The method shifts the yielding member so the opposing faces clamp the particular tissue therebetween with the force from the spring via a transfer rod or by the hydraulic coupling or the slip clutch for a range of pressure.

Claims

1. A surgical clamp for sealing and/or joining tissue, comprising:

an elongated support having a user end and a patient end;

an actuator for operation by a user;

a pair of end effectors proximal to said patient end wherein at least one of said pair of end effectors is attached to said actuator to control the relative motion between said pair of effectors;

a lost motion connection between at least one of said pair of end effectors and said actuator, said lost motion connection for transferring user manipulation of the actuator to at least one of said pairs of end effectors so as to maintain a predetermined clamping force within a preferred range irrespective of the user manipulation during sealing of the tissue between said pair of end effectors;

an active electrode disposed on one of said pair of end effectors;

a return electrode disposed in contact with the tissue and which forms an electrical circuit between said active and said return electrodes;

an electrosurgical energy supply for transmitting electrosurgical energy through said electrical circuit and across said active and return electrodes when the tissue is clamped between said end effectors; and

a control associated with the electrosurgical energy supply adapted to apply electrosurgical energy to the tissue that is held in response to the application of the predetermined clamping force for sealing the tissue between said pair of end effectors.

2. A surgical clamp according to claim 1 wherein said end effectors each comprise an opposing face adapted for contact with the tissue.

3. A surgical clamp according to claim 2 wherein said lost motion connection comprises a yielding member which supplies the predetermined clamping force to said opposing faces of the end effectors during clamping and sealing.

4. A surgical clamp according to claim 3 wherein a locking mechanism retains said predetermined clamping force between said opposing faces of said end effectors.

5. A surgical clamp according to claim 4 wherein said locking mechanism is selectively positionable such that said predetermined clamping force from said yielding member can be selectively set and locked to retain said predetermined clamping force in accord with a particular tissue being sealed.

6. A surgical clamp according to claim 1 wherein said electrosurgical energy supply comprises an electrosurgical generator having a feedback circuit in circuit with the active and return electrodes, said feedback circuit responsive to energy delivery across the tissue clamped between said pair of end effectors.

7. A surgical clamp according to claim 6 wherein said feedback circuit comprises an impedance circuit responsive to the impedance of the tissue between said active and return electrodes during delivery of said electrosurgical energy.

8. A surgical clamp according to claim 6 wherein said feedback circuit comprises a temperature sensor disposed on one of said effectors, said temperature sensor responsive to the temperature of the tissue between said end effectors during delivery of said electrosurgical energy.

9. A surgical clamp according to claim 3 wherein said yielding member comprises a spring.

10. A surgical clamp according to claim 9 wherein said spring is proximal to said user end of said surgical clamp.

11. A surgical clamp according to claim 9 wherein said lost motion connection comprises an elongated transfer rod disposed between said spring and said pair of end effectors for movement thereof between an open position adapted to receive the tissue and a clamped position for maintaining said predetermined clamping force on the tissue.

12. A surgical clamp according to claim 1 wherein said return electrode is disposed on one of said pair of end effectors opposite said active electrode.

13. A surgical clamp according to claim 1 wherein said return electrode is disposed on one of said pair of end effectors which carries said active electrode and an electrical insulation is disposed between said active and return electrodes.

14. A surgical clamp according to claim 1 wherein said return electrode is a pad adapted to be connected to the tissue.

15. A surgical clamp according to claim 3 wherein said yielding member comprises a hydraulic coupling.

16. A surgical clamp according to claim 3 wherein said yielding member comprises a slip clutch.

17. A surgical clamp according to claim 3 wherein said pair of end effectors have the opposing face of an area with each opposing face of an area having an equal and preset area, the actuators applies a first force adapted to grip the tissue therebetween and the actuator when advanced by the user applies a second greater predetermined clamping force from the yielding member so that pressure is applied to the particular tissue to clamp between the opposing faces with closure force in a range of 300 to 2500 grams.

18. A clamping force mechanism for an instrument for allowing a user to clamp and apply force and electrosurgical energy to seal and/or join particular vascular tissue of a patient comprising:

an elongated support having a user end and a patient end;

an actuator at the user end for operation by the user;

a pair of end effectors at the patient end, at least one of the pair of end effectors connected to the actuator for operation thereby and from the user end to control the relative motion between the pair of end effectors, the pair of end effectors each having an opposing face of an area adapted to be used for contact with the particular tissue of the patient;

a lost motion connection between at least one of the pair of end effectors at the patient end and the actuator at the user end, the lost motion connection for transferring user manipulation of the actuator to at least one of the pair of end effectors for maintaining a predetermined clamping force over the opposing face of an area during sealing of particular tissue of the patient between the pair of end effectors, said lost motion connection comprising a hydraulic coupling proximal to said user end and the opposing faces are adapted to clamp particular tissue of the patient therebetween with the predetermined clamping force from the hydraulic coupling over the opposing face of an area to achieve the predetermined clamping force during clamping and while sealing;

an active electrode adapted to be carried on one of the pair of end effectors;

a return electrode in contact with the tissue of the patient for forming an electrosurgical circuit between the active and return electrodes;

an electrosurgical energy supply connected across the active electrode of the pair of end effectors and the return electrode, the electrosurgical energy supply for delivery of electrosurgical energy through the electrosurgical circuit between and across the active electrode and the return electrode when the particular tissue of the patient is held by the pair of end effectors; and

a control associated with the electrosurgical energy supply adapted to apply electrosurgical energy to the particular tissue of the patient that is held in response to the application of the predetermined clamping force for sealing the particular tissue between the pair of end effectors.

19. A method for sealing and/or joining tissue, comprising the steps of:

providing;

an elongated support having a user end and a patient end,

an actuator for operation by a user, a pair of end effectors proximal to said patient end wherein at least one of said pair of end effectors is attached to said actuator to control the relative motion between said pair of effectors,

a lost motion connection between at least one of said pair of end effectors and said actuator, said lost motion connection for transferring user manipulation of the actuator to at least one of said pairs of end effectors so as to maintain a predetermined clamping force within a preferred range irrespective of the user manipulation during sealing of the tissue between said pair of end effectors,

an active electrode disposed on one of said pair of end effectors,

a return electrode disposed in contact with the tissue and which forms an electrical circuit between said active and said return electrodes, an electrosurgical energy supply for transmitting electrosurgical energy through said electrical circuit and across said active and return electrodes when the tissue is clamped between said end effectors, and

a control associated with the electrosurgical energy supply adapted to apply electrosurgical energy to the tissue that is held in response to the application of the predetermined clamping force for sealing the tissue between said pair of end effectors;

transferring user manipulation of the actuator to the pair of end effectors through the lost motion connection;

maintaining a predetermined clamping force during sealing of the tissue between the pair of end effectors with the lost motion connection; and

applying electrosurgical energy to the tissue to effect sealing in response to the application of the predetermined clamping force.