Method of vascular tissue sealing pressure control

#A clamping force mechanism for an instrument allows a user to apply force within an preferred range to hold particular vascular tissue of a patient during application of electrosurgical energy to seal and/or join the particular tissue.

#Sealing and/or joining of particular vascular tissue during surgery is an essential part of an operation or procedure. Sutures, staples and adhesives have been used with varying levels of success. These prior techniques and the material and equipment used fail to minimize or limit the damage to the particular tissue and most importantly do not eliminate foreign body reactions of the patient to the added material. Specifically, the reaction of the patient's body is normally to surround the foreign body, i.e. added scar tissue, with barrier cells to thereby isolate the foreign matter from the normal cells within the patient. Consequently, the scar or evidence of the trauma is increased in size. The added material increases the cost of any surgical operation or procedure and post surgical concerns and healing.

#Vascular tissue sealing and/or joining is important to the minimization of and/or elimination of bleeding or to the reconnection of tissue structures after surgical removal of undesirable organs or growths. Electrosurgery has been used to cut and coagulate tissue but the control needed to cleanly seal and/or join cut tissue and coagulate the bleeders has been lacking particularly in highly vascularized tissue, i.e. the particular patient tissue of interest and concern herein. Specifically, various approaches to coagulation, fulguration, cauterization for forming minimal and or flexible eschar over the bleeders have been tried. Different high frequency waveforms for coagulation by electrosurgical energy, argon gas enhanced coagulation and non sticking electrosurgical electrodes have been designed manufactured and sold with varying degrees of success at reducing healing time and the amount of evidence of surgical intrusion. All of the foregoing increases cost and complexity of surgical healing.

#FIG. 1 is a schematic view of an electrosurgical supply and circuit for a clamping force mechanism to allow a user to apply force within an preferred range to hold particular vascular tissue of a patient during application of electrosurgical energy to seal and/or join the particular vascular tissue.

#FIG. 2 is a side view in partial cross section taken along lines 2--2 of FIG. 1 and showing the clamping force mechanism wherein a spring is used as a lost motion connection between the user and end effectors shown herein in a fully open position.

#FIG. 3 is a side view in partial cross section taken along lines 3--3 of FIG. 1 and showing the clamping force mechanism wherein the end effectors are shown in closed position.

#A clamping force mechanism 10 of an instrument allows a user to clamp and apply force and electrosurgical energy to seal and/or join particular vascular tissue of a patient 11, in FIG. 1. The clamping force mechanism 10 includes an elongate support 12 particularly good for endoscopic procedures having a user end 13 and a patient end 14. An actuator 15 is at the user end 13 or operation by the user. A pair of the end effectors 16 is at the patient end 14 and the pair of end effectors 16 connect to the actuator 15 for operation thereby and from the user end 13 to control the motion of the pair of end effectors 16. The pair of end effectors 16 each have an opposing face 17 of an area for contact with the particular tissue of the patient 11 as shown in FIGS. 2, 3, 4 and 5.

#A lost motion connection 18 is positioned between the pair of end effectors 16 at the patient end 14 and the actuator 15 at the user end 13, in FIGS. 2, 3, 4 and 5. The lost motion connection 18 transfers user manipulation of the actuator 15 to the pair of end effectors 16 for maintaining a predetermined clamping force application during sealing the particular tissue of the patient 11 between the pair of end effectors 16. A yielding member 19 is in the lost motion connection 18 so the opposing faces 17 clamp the particular vascular tissue of the patient 11 therebetween with force from the yielding member 19. The yielding member 19 includes a spring 20, as part of the lost motion connection 18, between the pair of end effectors 16 at the patient end 14 and the actuator 15 at the user end 13. The spring 20 is located near the actuator 15 at the user end 13.

#An elongated transfer rod 21 connected to the lost motion connection 18 is located between the spring 20 near the actuator 15 and the pair of end effectors 16 at the patient end 14, in FIGS. 2, 3, 4 and 5. The rod 21 couples to the pair of end effectors 16 for movement thereof between an open position in FIG. 2 for receiving the particular tissue of the patient 11 to a clamping position for maintaining the predetermined force on the particular tissue of the patient 11 between the pair of the end effectors 16.