What is tubal ligation?
Female sterilization is surgery performed on women to prevent pregnancy and it may be done by means of bilateral tubal ligation, where the fallopian tubes on both sides are blocked. There are many different methods such as cutting, tying, sealing, or attaching a ring, clamp or clip on the fallopian tubes to block it. Since it is a permanent form of birth control, a woman should be absolutely sure about wanting this procedure before going ahead with it. Female sterilization will not result in amenorrhea (no period) or anovulation (no ovulation). A woman will still ovulate and menstruate every month and a tubal ligation will not reduce sexual desire.
How does Female Sterilization Work?
During ovulation, an ovum or egg is released by the ovary, which makes its way into the fallopian tube. In a woman with regular periods, ovulation usually occurs 12 to 14 days before the beginning of the next period. During intercourse, sperms travel up the vagina, through the cervix and uterus, to reach the tubes.
If intercourse takes place around the time of ovulation, a sperm may fertilize the ovum while it is in the fallopian tube. The fertilized ovum then travels down through the tube to reach the uterus, where it attaches itself and starts to grow as the fetus. If fertilization does not take place, the ovum is destroyed and the uterine lining is shed as menstruation.
Since fertilization takes place within the fallopian tubes, after tubal sterilization the sperm is unable to reach the ovum and thus pregnancy is prevented.
Anatomy of the Fallopian Tubes
The fallopian tubes are attached to the upper part of the uterus, one on either side, and open into the uterus. They are about 4 inches (10 cm) long and 0.2 inches (0.5 cm) in diameter. The fallopian tube can be divided into 4 parts :
- The outermost end known as the infundibulum, which lies near the ovary, with an opening (ostium) through which the ovum enters the tube.
- The ampulla, which is the dilated part of the tube.
- The isthmus, which is the narrow part of the tube adjacent to the uterus. This portion of the tube is the preferred site for most sterilization procedures.
- The intrauterine or intramural part of the tube lies within the uterine wall, ending in the tubal ostium, which is the opening into the uterine cavity.
Surgical Approaches for Female Sterilization
Tubal ligation may be performed under general anesthesia (GA), regional or spinal anesthesia, or local anesthesia with sedation. The procedure normally takes about 20 to 30 minutes. It can be performed as postpartum or puerperal sterilization (within 24 hours after delivery) in a hospitalized patient or may be done at any other time (interval ligation) on an outpatient basis. Overnight hospital stay is usually not necessary.
Laparoscopy and minilaparotomy are the most common surgical approaches to tubal ligation. Sterilization by laparotomy (a large abdominal incision) is rarely done these days. A tubal ligation can be done with ease during a Cesarean section if consent has been given beforehand and the newborn baby is healthy. Hysterectomy, as a method of sterilization, is not performed unless there are other indications for the operation.
Laparoscopic Tubal Ligation Procedure
Laparoscopic ligation may be done at any time except for postpartum sterilization (after delivery). A tiny incision, about 0.5 inches (1 cm), is made in or near the umbilicus (belly button) and a gas (usually carbon dioxide) may be passed into the abdomen to inflate it. This allows better visibility and access to the pelvic organs by moving away the abdominal wall.
The laparoscope is inserted through this incision. The laparoscope is a long, thin telescope-like instrument with a light and a tiny camera fitted at the end which sends magnified images onto a television screen. The surgeon performs the operation guided by these images. A second incision near the pubic hairline is made, through which the surgical instruments can be inserted. An instrument passed through the vagina helps to move the uterus. The tubes may be blocked by any of the techniques such as cutting, tying, or by using clips or bands, or by electrocoagulation. The laparoscope is then withdrawn and the incision closed with one or two stitches.
The laparoscopic procedure may not be suitable in :
- Obese patients.
- Those who have had previous surgery, especially multiple abdominal surgeries with adhesion formation.
- Immediately after delivery (puerperal ligation).
- Those with diaphragmatic hernia.
- Severe heart or lung disease.
A laparotomy with an incision size smaller than 5 cm is called a minilaparotomy. An incision, about 1.2 to 1.6 inches (3 to 4 cm) is made just above the pubic bone (in case of interval ligation) or just below the umbilicus (in case of puerperal ligation). The uterus and the fallopian tubes are reached after cutting through the layers of the abdomen. Both tubes are ligated, using any of the techniques. The abdomen is then closed in layers.
Another method of sterilization is the use of Essure microinserts for hysteroscopic sterilization. Here, small coils are inserted into the tubes through the vaginal route, using a hysteroscope (a flexible viewing tube). No incision is necessary and the procedure may even be performed in a doctor’s office under local anesthesia with or without the use of sedatives. The microinserts are made up of polyethylene terephthalate (PET) fibers wrapped around a stainless steel core, surrounded by 24 coils of nickel-titanium alloy. The PET fibers induce scar tissue formation around the coils, which block the tubes.
Complete blockage of the tubes may take about 3 months and can be confirmed by a hysterosalpingogram (x-ray done after passing a dye into the uterus and tubes through the vagina).
The Adiana procedure, like Essure, is performed through the vaginal route. This method of sterilization has been approved recently by the FDA. In this procedure, a catheter is introduced into the fallopian tube through a hysteroscope. The catheter is used to apply low-level radiofrequency energy to create a superficial lesion. A porous plastic implant (matrix) is placed on the lesion and left in place. The surrounding tissues grow into it and ultimately block the tube in about 3 months’ time.
The advantages of hysteroscopic sterilization are :
- It can be performed as an office procedure, under local anesthesia.
- Injury to bladder, bowel or major blood vessels is not a risk.
- The procedure can be performed in obese patients.
- Abdominal or pelvic adhesions do not hamper the procedure.
However, this sterilization method is contraindicated in “
- Women who are allergic to nickel or contrast media.
- Pelvic inflammatory disease (PID).
- Suspected pregnancy.
- Women who have had a delivery or abortion within the last 6 weeks.
- Patients in whom only one microinsert may be inserted.
In this procedure, microendoscopes (1.2 to 2 mm) are used with tiny incisions (5 to 7 mm) for bipolar coagulation or mechanical methods of tubal blockage.
Techniques of Tubal Sterilization
The actual technique used to perform a tubal ligation involves first isolating the fallopian tubes by identifying the fimbriated end of the tubes. This is a very important step so that any other structure such as the round ligament is not ligated by mistake. The tube is then ligated, using any of the following techniques
This is the most commonly performed technique for puerperal tubal ligation. The mid portion of the fallopian tube is lifted by means of a Babcock clamp to form a loop, which is tied with plain catgut suture. The top of the loop is cut off and the closed ends of the tube move away from each other from each other, creating a gap of 2 to 3 cm between the cut ends of the tube. A similar procedure is done on the other tube.
There are many different modifications of the Pomeroy technique.
In this method, about 5 cm of the muscular tube towards the uterine end is cut off but the fimbriated end is left untouched. For puerperal ligation, this procedure is modified by performing a fimbriectomy (removal of the fimbrial end of the tube). In essence, this is a salpingectomy (removal of the fallopian tube) since the fimbria, along with a large portion of the tube, is resected. The low failure rate achieved with this technique is due to such a large segment of the tube being removed.
This method is similar to Pomeroy technique, but each limb of the loop is tied separately. This helps to separate the cut ends of the tube and thus reduces risk of recanalization.
The tube is lifted and cut. The cut proximal end (uterine end) of the tube is buried in a tunnel in the anterior uterine wall. This technique is designed to be used along with a Cesarean section.
Sterilization by Fimbriectomy
The tube is lifted a little away from the fimbrial end. Double ligations are placed near the fimbrial end and the tube is cut between the sutures.
This procedure is similar to Pomeroy but without tubal resection. The tubes are crushed and ligated with non-absorbable suture.
This technique involves blocking the tubes by means of mechanical devices such as
- Falope ring – a non-reactive silicone rubber band is placed around a loop of the tube by means of an applicator.
- Hulka clip – a plastic clip is placed across the tube which is held in place by a steel spring.
- Filshie clip – a titanium and silicone clip is used.
This technique causes less tissue damage and may give better chances of reversal.
Electrosurgery is preferred when the tubes are swollen or cannot be easily mobilized for placement of a mechanical device. Use of bipolar current may be safer than unipolar current and causes less tissue damage.
In bipolar tubal ligation, the mid portion of the tube is grasped and held up between two poles of the bipolar forceps and an electrical current is applied, which passes through the tube between the two ends of the forceps. There is s greater chance of tubal damage with this procedure hence less chance of reversal.