In the bipolar electrocoagulation technique, the midisthmic portion of the tube and adjacent mesosalpinx are grasped with special bipolar forceps, and radiofrequency electric current is applied to three adjacent areas, coagulating 3 cm of tube (Fig. 10.11). The tube alone is then recoagulated in the same places. The radiofrequency generator must deliver at least 25 watts into a 100-ohm resistance at the probe tips to ensure coagulation of the complete thickness of the fallopian tube and not just the outer layer; otherwise, the sterilization will fail (285).
To apply the Falope ring, the midisthmic portion of the tube is grasped, with tongs advanced through a cylindrical probe that has the ring stretched around it (Fig. 10.12A). A loop of tube is pulled back into the probe, and the outer cylinder is advanced (Fig. 10.12B), releasing the Silastic ring around the base of the loop of tube, producing ischemic necrosis (Fig. 10.12C). If the tube cannot be pulled easily into the applicator, the operator should stop and change to electrical coagulation rather than persist and risk lacerating the tube with the Falope ring applicator. The banded tube must be inspected at close range through the laparoscope to demonstrate that the full thickness of the tube was pulled through the Falope ring.
Figure 10.11 Technique for bipolar electrocoagulation tubal sterilization.
Figure 10.12 Placement of the Falope ring for tubal sterilization.
The Hulka clip is placed across the midisthmus, ensuring that the applicator is at right angles to the tube and that the tube is completely contained within the clip before the clip is closed. The Filshie clip is placed at right angles across the midisthmus, taking care that the anvil of the posterior jaw can be visualized through the mesosalpinx beyond the tube to ensure that the complete thickness of the tube is completely within the jaws of the clip before it is closed (Fig. 10.13).
The electric plus band or clip techniques each have advantages and disadvantages. Bipolar coagulation can be used with any fallopian tube. The Falope ring and Hulka and Filshie clips cannot be applied if the tube is thickened from previous salpingitis. There is more pain during the first several hours after Falope ring application. This can be prevented by bathing the tubes with a few milliliters of 2% lidocaine just before ring placement. Failures of the Falope ring or the clips generally result from misapplication, and pregnancy, if it occurs, is usually
Risks of Tubal Sterilization
Figure 10.13 Filshie clip for tubal sterilization. (Courtesy of CooperSurgical, Inc., Trumbull, CT.) intrauterine. After bipolar sterilization, pregnancy may result from tuboperitoneal fistula and is ectopic in more than 50% of cases. If inadequate electrical energy is used, a thin band of fallopian tube remains that contains the intact lumen and allows intrauterine pregnancy to occur. Thermocoagulation, the use of heat probes rather than electrical current, is employed extensively in Germany for laparoscopic tubal sterilization but is little used in the United States.