Laparoscopic Sterilization: Prevention of Failures

Female sterilization is the most common contraceptive method used worldwide, accounting for approximately 30% of current contraceptive users.¹ In the United States 10.3 million women utilize sterilization as their contraceptive method.² Pregnancies due to method failure, while uncommon, can occur and depend on both the age the woman was at the time of sterilization and what type of sterilization procedure was performed. Prevention of unintended pregnancy depends on choosing the appropriate type of procedure and on adhering to proper surgical technique.

The best data for sterilization failures comes from the 1996 US Collaborative Review of Sterilization, or the CREST study.³ In CREST, over 10,000 women who had a sterilization procedure from 1978 to 1986 were followed for up to 14 years.

In examining the risk of sterilization failure, each method impacts risk of failure. As shown in Table 1, the cumulative 10-year probabilities of failure were the highest for spring clip sterilization and lowest for postpartum partial salpingectomies. The rate of failure also depends on a woman’s age at sterilization. Women younger than 28 years old are at a higher risk for sterilization failure for all methods except interval partial salpingectomy compared to women older than 34 years old at the time of sterilization. Beyond age 34 none of the differences among the methods are significant.³

Table 1. Relative risk of sterilization failure by method³

 

Several methods of laparoscopic sterilization can be utilized. The surgeon can apply bands or clips to the tubes, desiccate tubes with either unipolar or bipolar cautery, or simply remove the tubes. A recently introduced method involves hysteroscopic insertion of coils into the tubes. Assessment of pregnancy rates after various laparoscopic and hysteroscopic sterilization using an evidence-based Markov model demonstrated that in the expected pregnancy rates at 1 and 10 years could be higher than expected if patients do not comply with the need for follow-up after the hysteroscopic sterilization (Table 2).⁴

Table 2 Pregnancy rate per procedure at 1 and 10 years

 

Measures to decrease method failure for laparoscopic banding and occlusive procedure:

1. Clearly identify the fallopian tubes and follow them out to the fimbriated ends;
2. Place the occlusive device 2–3 cm from the uterotubal junction;
3. Place the devices properly as per the manufacturer’s instructions;
4. Handle tissue gently and keep tubes off tension;
5. Deploy the devices slowly;
6. Ensure the entire tubal lumen is occluded by the device being used.

 

Banding procedure

The Falope Ring (Falope Ring Band, Cabot Medical, Langhorne, PA) is a small silicone band with a solution of 5% barium sulfate to allow identification on radiologic imaging.⁵ The Falope Ring applicator device has two cylinders, one inside the other. One or two Falope rings are placed on the outside applicator and forceps which are used to grasp the fallopian tube reside in the inside cylinder.

Once the tube has been identified, the forceps should grasp the mesosalpinx below the tube 2–3 cm distal to the uterotubal junction. This distance is essential, as a distal portion of tube is more dilated and may not easily be brought into the cylinder, and a more proximal portion will not allow sufficient mobility of the tube. When done correctly, 2 cm of tube will be pulled into the cylinder, and the ring will be released at the base of the loop where it will constrict tightly around this tissue. The tissue will then subsequently necrose, heal, fibrose and occlude. Specific to the Falope ring, remember:

1. Be gentle with the mesosalpinx. Tearing this highly vascular tissue with forceps can cause bleeding.
2. At least 2 cm of fallopian tube will be pulled into the cylinder, sometimes this may require lysis of adhesions to free the tube.⁶
3. The ring applicator should receive routine maintenance to perform properly. Note: a disposable Falope ring applicator may be available and is intended for single patient use.
4. The ring should be placed on the applicator just before it is placed on the tube (no more than 5 minutes before application, as this may result in permanent stretching of the silicone).

If the tube is transected by the device, this will increase the likelihood of spontaneous regeneration of the tubal lumen and risk of sterilization failure.⁷

Occlusive procedure

There are two occlusive devices that can be used to block the fallopian tubes. First, the Filshie clip (CooperSurgical, Lake Forest, CA) is a hinged device made of titanium lined with silicone rubber.⁸ After the fallopian tube has been identified, the Filshie clip is brought to an area of tube 2–3 cm distal to the uterotubal junction. The lower edge of the clip is then visualized through the mesosalpinx to confirm that, when closed, the clip will completely occlude the tubal lumen. The clip is then closed via the applicator, and when closed flattens the curved upper jaw of the clip, occluding the tube. The upper jaw of the clip has a leading edge that extends under the lip of the lower jaw. As necrosis occurs, the rubber expands to keep the lumen blocked. Over time the tube divides into two separate peritoneum-covered stumps. Unique to the Filshie clip, there are several points to remember:

1. The clip should be applied at a 90 degree angle, perpendicular to the lumen of the tube.
2. The bottom jaw of the Filshie clip should be clearly visualized in the mesosalpinx prior to closure of the device.
3. The clip should not transect or tear the tube, as this will increase the chance of the tubal lumen regenerating.
4. If the first clip is not applied at 90 degrees or is not at the proper distance from the uterus, a second clip can be applied to the same tube.

The second type of occlusive device is the Hulka clip (Hulka-Clemens, Richard Wolf, Rosemont, IL). The Hulka clip is a hinged, spring-loaded plastic clip with interlocking teeth.⁹ The Hulka clip is designed to occlude the isthmic portion of the tube over 48 hours. After the publication of the CREST study the Hulka clip became less popular due to its comparatively high failure rate.

Bipolar coagulation

Unipolar coagulation, as mentioned in the CREST study, is no longer used due to association with thermal injury to the bowel.^{10, 11, 12} Bipolar coagulation, while safer than unipolar coagulation, still carries a far greater risk of ectopic pregnancy, as shown by the CREST study. Women younger than 30 who have a sterilization by bipolar coagulation are 27 times more likely than those who had a postpartum partial salpingectomy to have an ectopic pregnancy.¹³

Bipolar coagulation utilizes a device with two small paddles (i.e. Kleppinger device), which reduces the chance for sparking of the current to surrounding tissue. Once the fallopian tube is identified, the tube should be grasped 2–3 cm from the uterotubal junction. After confirming that the bipolar device is a safe distance from bowel and other organs, current can be applied with the concurrent use of an ammeter or current flow meter to ensure complete coagulation. The tube should then be regrasped at proximal and sites such that 3 cm of contiguous tube is coagulated. The tubes should not be transected, as this actually can increase the chance of fistula formation. To increase success with bipolar cautery:

1. Use a cutting wave form at 25–35 watts.¹⁴
2. Use an ammeter or current flow meter to confirm complete electrocoagulation of the tissue.⁷
3. Coagulate 3 cm of contiguous tube with adequate energy.
   

 

 

Compared to laparoscopic sterilization, hysteroscopic sterilization is a less invasive and less expensive option.^{15, 16} The Essure device (Conceptus, San Carlos CA) was introduced in 2002 and is a soft, flexible microinsert that is placed under hysteroscopic visualization into the proximal fallopian tube.¹⁷ From the 5 year data, the pregnancy rate for Essure is less than a postpartum partial salpingectomy; approximately 1.64 pregnancies per 1000 women were noted at 5 years, versus 6.3 per 1000 women for postpartum partial salpingectomy in the CREST study.¹⁸ However, long-term data are limited.¹⁹ A 10-year retrospective analysis of worldwide pregnancy reports found that 0.15% of users experienced method failure consistent with the manufacturer's age-adjusted effectiveness at 5 years.²⁰ A recent publication demonstrated that when a confirmatory test is not completed to prove tubal occlusion, it is possible that the pregnancy rate could be as high as 96 per 1000 women.⁴

The Essure device is placed transcervically via a guidewire in a constricted, wound-down configuration into the fallopian tube and then released from the delivery system. Once released, the outer coil expands to fit to the dimension of the fallopian tube. A second stainless steel inner coil has polyethylene terephthalate (PET) fibers that are woven in and around it. The outer nickel titanium coil provides stabilization during the first 3 months following device placement, in which time the PET fibers cause tissue to grow into the coils of the stainless steel inner coils. Over 3-months occlusion of the tubes occurs by this tissue in-growth, fibrosis and chronic inflammatory response. In the United States, a hysterosalpingogram is then performed 3 months after placement to confirm tubal occlusion and proper device placement as per Food and Drug Administration requirement.²¹ Other confirmatory tests used outside the US include an abdominal radiograph or pelvic ultrasound.^{22, 23, 24} These alternative studies, however, do not confirm tubal occlusion. During this 3 month period alternative contraception must be used. If tubal occlusion is not confirmed at that time, it is recommended to wait an additional 3 months and then perform another hysterosalpingogram and to continue alternative contraception until tubal occlusion is confirmed.

To increase success with Essure:

1. Good visibility of the tubal orifices during hysteroscopy is essential.²⁵ Ideally the endometrium should be primed prior to the procedure by suppressing the menstrual cycle. A progestin-containing method is best, such as depot medroxyprogesterone acetate (DMPA). Alternatively, oral contraceptive pills can suffice. If the patient is unable to use hormonal contraception, then it is best to perform Essure in the first half of the menstrual cycle when the endometrial lining is thin.²¹
2. When deploying the microinsert, there 3–8 coils should be visible in the uterine cavity. If the inserts are placed too proximally, (and more than 8 coils are seen in the cavity) there is an increased risk of expulsion.¹⁰

Nonsteroidal antiinflammatory drugs (ibuprofen 600 mg PO or toradol 15 or 30 mg IM) pre-procedure can increase the chance of successful insert placement possibly due to prevention of tubal spasm.²⁶ The use of warmed sterile distension media (i.e. normal saline, lactated ringers) is also recommended.

If performing a second sterilization procedure after a failed procedure, there are several important steps to take. Upon laparoscopic examination of the pelvis, photographs and a detailed description should be obtained. If the patient is not currently pregnant or does not have current signs or symptoms of cervicitis or pelvic infection, chromopertubation of the tubes may confirm or refute true occlusion of the tubes.²⁷

For a failed tubal ligation, either total bilateral salpingectomy or removal of patent portion of the tube should be performed and then examined by a pathologist to identify the point of failure. If Filshie or Hulka clips were used, they should be carefully removed to attempt to identify a device defect. Several microscopic slides of the area in question should be made by a trained pathologist.²⁷

After the corrective surgery is complete, the operative note should be dictated immediately.²⁷