Laparoscopic Sterilization Techniques

At a resident's education conference, Dr. Richard M. Soderstrom, M.D. presented the following handout on today's evidence based evaluation of laparoscopic sterilization methods. Dr. Soderstrom is the author covering this subject in the USA'a first textbook on Laparoscopy, Ed. JM Phillips, Williams & Wilkins, 1977. Since then he has published widely on the subject and continues to act as a consultant to the FDA when new devices for sterilization are entertained.

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Preamble
Because female sterilization is one of the most common surgical procedures performed by gynecologists, litigation following sterilization failures has a significant impact. When the standard of care is questioned, it is usually a departure of the "standard of technique". The best way to correct this problem is through proper didactic education and observation during one's residency education. The following is a brief, concise overview of information that should be the core basis for such education.

History and Experience
For the past three decades, the laparoscopic methods of female sterilization have received wide attention in the literature focusing on electrical or mechanical methods. Each method was designed and developed by inventors who made clear recommendations as to the proper use and application of their technique and method. Of these, the bipolar electrical method has been the most popular. Unfortunately, different techniques may be "modified" by an individual surgeon, who in essence invents another method without the luxury of adequate statistics. Until recently, statistical reports on the success and/or failure of techniques were usually flawed because of anecdotal experience, retrospective review and short-term follow up or subject to "lost to follow up" bias. In April 1996, the Center for Disease Control (CDC) published the only prospective study of the common methods of sterilization used in the United States.1 It took fourteen years and over 10,000 patients to obtain a ten year follow up of each technique studied. More than a dozen teaching centers participated making the power of the outcome statistics strong. The following comments are summarized from this report:

• Of the laparoscopic procedures described, unipolar electrocoagulation without transection has the lowest failure rate of all of the laparoscopic techniques to date. In recent years, problems with a high bipolar failure have become apparent including late ectopic pregnancies. Incompatible equipment and inadequate coagulation appear to play a major role in these failures.
• In general, when ring failures occur, it is secondary to spontaneous reanastomosis. Frequently, failures
  associated with a clip follow placement of the clip too distal on the tube, at oblique angles to the axis of the tube or misapplied to other structures.

Basic Requirements
When performing laparoscopic female sterilization, the following outlines the basic requirements as described by those who invented or developed each sterilization method.

Electrical methods - Unipolar or Bipolar

• Always use the cutting mode set at 25 to 30 watts. Most bipolar generators only deliver electrical current in the cutting/desiccation mode or waveform.
• Desiccate at least 2.0 cm, preferably 3.0 cm of contiguous tissue. There is no data supporting desiccation followed by transection as any improvement.
• Desiccate the isthmus portion of the fallopian tube; spare the cornua to reduce fistula formation.
• With bipolar instruments, the use of an ammeter until current flow reaches zero reassures the surgeon that complete desiccation has occurred.

Clip methods

• Place a clip 3 cm from the cornua at a 90 degree angle. 
• With the Hulka ClipT, check for the "envelope" sign (a flattening of the grasp area of tube) after application. If in doubt, apply another clip adjacent to the first.
• With the Filshie ClipT, expose the lower jaw seen through the mesosalpinx before closing the clip on to the tube.

Band method

• Because the silastic rubber band may lose its memory if it is stretched over the applicator beyond 15 minutes, apply the silastic band to the band applicator just before application. 
• Grasp the isthmus portion, 3-4 cm from the cornua. 
• Squeeze the applicator handle slowly to reduce the risk of tubal transection.

References:

1. Peterson HB, Zhisen X, Hughes JM, Wilcox LS, Tylor LR, Trussel J. The risk of pregnancy after tubal sterilization: Findings from the U. S. Collaborative Review of Sterilization. Am J Obstet Gynecol 1996; 174 (4): 1161-1170

2. Peterson HB, Zhisen X, Hughes JM, Wilcox LS, Tylor LR, Trussel J. Pregnancy after tubal sterilization with bipolar electrocoagulation. Obstet Gynecol 1999; 94 (2): 163-167