Click here to view next page of this article

 

New Methods of Tubal Ligation

If we look at sterilization and contraceptive usage in the United States, this is a recent study, you can think that about 30% of women rely on sterilization, about another 30% rely on the pill so that accounts for 60% of users and another 20% relying on barrier contraception, condoms and diaphragms and then everything else representing the final 20% and this includes Depo-Provera.

In the United Kingdom, in Great Britain and the sterilizations for males and female are about equal and in some other parts of the world like New Zealand, male sterilization is favored over female sterilization, but world wide, female sterilization seems to be preferable to male sterilization by about 2 to 1. In terms of numbers in the United States, there are between 600,000 to 700,000 female sterilizations every year.

There is no single procedure that is available today clinically that meets all this criteria. Some come close and weíll come back to this toward the end of my presentation. I would like to start for the first few minutes with male sterilization or vasectomy because itís something that we are counseling couples, itís something we should know about and we should know the pluses and the minuses. A vasectomy is a simple, safe operation that is highly effective.

Letís go on to what is perhaps a greater interest to the audience, and thatís female sterilization and in relation to female sterilization, we are talking about tubal ligation. This is a safe, effective and simple procedure and as we mentioned earlier, large numbers are done every year in the United States.

This number includes post abortal, postpartum and interval sterilization, 640,000 or more per year. Here are three principals that apply to any sterilization procedure that you might do or consider. The first one is that the effectiveness of the procedure is usually related to the degree of tissue compromised. So those procedures that remove or impair a large amount of tube are usually the ones with the lower failure rates usually. Conversely, failure rates are inversely proportional to the degree of tubal destruction and finally, reversibility is directly proportional to the amount of normal tube remaining, so keep these generalizations in mind as we talk about the different sterilization procedures.

I know you know how to do this, I will just show you these pictures and it will set the stage with looking at some of the other procedures. A loop of tube is elevated with a Babcock clamp or single suture is put on the tube, itís ligated and then a portion of tube is excised and sent for pathology for documentation and then with the absorption of the suture, one gets tubal discontinuity and this is the end result. With the Madlener procedure, which was the first of the sterilization procedures that was developed, is a totally different procedure, a loop of tube is elevated and crushed with a surgical clamp.

At the present time, most of the interval sterilizations in the United States are done laparoscopically and the fall into two categories, the electrocoagulation procedures are the unipolar, or bipolar, and those procedures that rely on some sort of mechanical occlusive device, a band or clip. Low temperature thermal coagulation is actually a good and interesting procedure that has a good physiologic surgical basis but itís not well used.

This slide shows division of the tube and thatís no longer necessary. The only thing that division does is it causes excessive bleeding but it doesnít change the failure rates in any way, so that itís not necessary if you are going to do a unipolar sterilization, but unipolar sterilizations are fairly rare because in 1974, because of the problems of unipolar sterilization and particularly bowel burns, bipolar sterilization was introduced and with bipolar sterilization, the way itís done most of the time today, will do three burns on the tube so that will compromise about 6 cm of the tube, but the failure rates on all studies seem to be on the high side and there are probably three reasons for this. The first one is that one cannot use tissue blanching as an end point, one has to use electron flow through the meter as the end point.

Letís go on and look at the fallopians, about 2 to 3 cm of tube is destroyed as itís drawn up into the applicator and I mentioned already that basically this is similar to the old Madlener technique. This is a ring being put on the tube as you see and then with the ring on the tube, this portion of the tube undergoes aseptic necrosis and often the ring will fall off and relocate to some other area close by. The problem most people have with this technique is that the applicator is very fragile and the prongs of the applicator have to be carefully aligned, otherwise it is possible quite easily to tear the mesosalpinx, and those of you that have used this know that with some of the larger tube, hyperemic tube, sometimes itís hard to get the tube all the way up into the applicator, but itís a good technique for those people who are trained in the technique and are comfortable with the equipment. With the tubal clips, I think highlight of these tubal clips is that less tube is destroyed and with the newer clips, they are much easier to apply. There are two clips that are on the market in the United States, the first one that achieved popularity was the Hulka Clemens spring loaded clip which is a plastic clip within the spring that is pushed down to close the clip over the tube. The failure rates with this clip as you will see from the Crest study tend to be on the high side.

Recently, for the past 2 Ĺ years, we have had the Field Sheath clip which is a clip that is widely used throughout the world and particularly in Canada where there has been a lot of experience with this clip and this is a titanium clip that is clipped through the mesosalpinx with a silicone liner, so as the tube undergoes aseptic necrosis, the silicone expands to fill that space. It destroys about 5 mm of tube so it destroys relatively little tube but provides for a good occlusion.

What about pregnancy rates and failure rates? For many years, we quoted failure rates in the range of two to four per thousand based on older studies that lasted, followed patientís for one or two years after surgery. In 2006 with the advent of the Crest study from the center for disease control, we had to revise our figures and our thinking. This is an interesting study that was conducted at 10 centers throughout the United States, university centers of 10,000 patientís between 78 and 86 and they followed these patientís for up to 12 years. There were 143 failures that were identified in this group of women.

We will talk about that in a moment, but the average figure now is 18.5 per thousand. The summary state of this paper is the one that I put on the slide for you. Tubal sterilization is a highly effective method of preventing pregnancy. However, pregnancy after sterilization occurs substantially more often than is generally reported. Further pregnancies occur more than one to two years after sterilization, thus establishing the concept of cumulative risk of pregnancy after sterilization. This is particularly important for women sterilized at a young age, and by young they mean under the age of 30. There were 47 ectopics in the group of 143 pregnancies and a large number of these ectopics were in patientís who had bipolar sterilization under the age of 30, so you can see here that is sort of a high risk for ectopic pregnancy. There were also studies of regret that were done on the same patientís and in general, there was very little regret of patientís having sterilization procedures. The patientís that were sterilized at a very young age were the ones that had a higher probability of regret as you would intuitively expect.

As far as reversibility is concerned, it seems to be that the estimated need is up to 1% probably less than 1% today with the type of informed consent that we do. We used to rely on micro surgery but today, most of the reversals are being done laparoscopically but since insurance usually does not pay for sterilization reversal, many of these patientís immediately go to IVF rather than just looking at a risk of 50% pregnancy after reversal versus almost the same with in vitro fertilization. The long term issues I will just mention very briefly, is there a post tubal sterilization syndrome, probably not, t here was a review in fertility and sterility of 200 articles and thatís the conclusion they came to. Is there a decreased risk of ovarian cancer, the answer is yes from the large epidemiologic study that was published recently of 77,000 women following sterilization with a slightly reduced risk for ovarian cancer, and reasons for this are not clear.

The only other things I want to talk about in relation to female sterilization are just a few of the new things, hysteroscopic sterilization has not been terribly successful, but recently with the newer technology, there are some new plugs that are being studied and it looks like we may in a few years have a hysteroscopic approach that we can use for sterilization, endometrial ablation interestingly enough has a low pregnancy rate, but of course these procedures are being done on older women so you might expect that, and there are some transcervical methods that are under investigation for injecting either tissue adhesives into the tubes or putting sclerosing agents like quinacrine into the uterus and in your handout there is reference to 100,000 quinacrine sterilizations that have been done, mostly in Southeast Asia, the failure rates are high, but itís a simple and inexpensive procedure. For the future, with the advent of 3-D ultrasound, it will give us an opportunity to approach the tubes transcervically without the hysteroscope perhaps with just a small guided device to either get a solution into the ova duct or plug into the tube and I show you this picture as one of the ways you can visualize the uterus with 3-D ultrasound. Itís really remarkable what we can see. I will come back to the ideal sterilization procedure, there is no one procedure that meets all this criteria in relation to male sterilization, perhaps the no scalpel vasectomy comes close in relation to surgical sterilization, the Pomeroy procedure comes close, relation to laparoscopic sterilization. If you want a reference, the ACOG sterilization material is good with the exception of the fact that the statistics are probably not up to date.