Female Sterilization Occlusion Techniques

Female sterilization prevents pregnancy by occluding or mechanically blocking the fallopian tubes, using one of several occlusion techniques.

Network: Fall 1997, Vol. 18, No. 1

Female sterilization prevents pregnancy by occluding or mechanically blocking the fallopian tubes. There are several different occlusion techniques -- tubes can be tied or "ligated," blocked with mechanical devices such as clips or rings, or scarred closed with electric current.

Gaining access to the tubes typically involves one of two types of incisions or approaches -- minilaparotomy or laparoscopy.

Minilaparotomy, or minilap, the most common approach, involves a 5 cm incision in the abdomen. The fallopian tubes are accessed through this small incision. Minilap is easier to provide in remote clinics or health centers because it does not require any special equipment.

Laparoscopy involves using an instrument called a laparoscope, inserted into the abdomen to see the tubes and guide the occlusion. The incision is much smaller, only about 1 cm. Using the laparoscope, a narrow stainless-steel tube with a fiber-optic cable, requires more extensive medical facilities.

AVSC International/D. Rosenzweig
Pomeroy Method	Clip Method

Four occlusion methods are widely performed, typically on the isthmic portion of the fallopian tube, the thin portion of the tube closest to the uterus:

Partial salpingectomy -- In partial salpingectomy, the most common occlusion method, the fallopian tubes are cut and tied with suture material. The Pomeroy technique, a widely used version of partial salpingectomy, involves tying a small loop of the tube and cutting off the top segment of the loop. Partial salpingectomy is considered safe, effective and easy to learn. It does not require any special equipment to perform; it can be done with only scissors and suture. Partial salpingectomy is not generally used with laparoscopy.

Clips -- Clips block the fallopian tubes by clamping down and cutting off the blood supply to a portion of the tubes, causing a small amount of scarring or fibrosis that prevents fertilization from occurring. The two most common clips are the Filshie clip, made of titanium, and the Wolf clip (also known as the Hulka clip), made of plastic. Clips are simple to use, but each type requires a special applicator.

Silicone rings -- Tubal rings, like clips, also block the tubes mechanically. A very small loop of the fallopian tube is pulled through the stretched ring. When the ring is released, it stops the blood supply to that small loop. The resulting scarring blocks passage of the sperm or egg. The Yoon Ring, made of silicone, is widely used.

Electrocoagulation -- Electrocoagulation uses electric current to coagulate or burn a small portion of each fallopian tube. Unipolar coagulation passes current through the forceps applied on the tubes, and the current leaves a woman's body through an electrode placed under her thigh. This technique is rarely used because it is associated with a higher risk of organ injury. In bipolar coagulation, current enters and leaves a woman through two ends of the forceps. Bipolar coagulation is safer, but slightly less effective than unipolar coagulation.

-- Sarah Keller

Sources:

1. World Health Organization, AVSC International. Medical Eligibility Criteria for Sterilization, Annotated Summary, Draft. New York: AVSC International, 1994.
2. Female sterilization. Popul Rep 1990;C(10).