When the abdominal organs are disturbed when they're moved during surgery or because of inflammatory disease, they may become stuck to each other by adhesions -- a form of scarring. Adhesion formation occurs in at least 25 percent of women after their first cesarean section, and the risk increases with subsequent c-sections. Adhesions can cause complications that may ultimately require further surgery.
Complications of Adhesions
Adhesions are the most common cause of bowel obstruction after abdominal surgery. The process of adhesion formation begins almost immediately after a c-section. However, there may be no untoward effect for months or years and some women never develop complications, despite the presence of internal adhesions.
Adhesions may increase the risk of ectopic pregnancy and infertility by kinking the tubes between the ovaries and womb, or causing folding of the uterus. Chronic pelvic pain may also result and be made worse during sexual intercourse. Second and subsequent operations on women with abdominal adhesions are more likely to result in prolonged operation, injury to the intestinal tract and more blood loss.
Risk of Adhesions
When compared to all other gynecologic operations, adhesion formation is only 1/2 as common after a single cesarean section. There is less manipulation of abdominal organs with a c-section compared other types of gynecologic surgery, and that may account for the decreased occurrence of adhesions. The risk increases with each procedure, however. In a December 2011 review article published in the journal "Reproductive Sciences," Dr. Awoniyi Awonuga and colleagues cited observations by others indicating that adhesion formation occurs in as few as 24 percent of women after the first c-section and as many as 83 percent after the third.
Bowel obstruction due to adhesions may require surgery to reopen the intestine. Chronic pain and infertility may also be alleviated by cutting through the adhesions, known as adhesiolysis. While often successful, new adhesions may form after any surgical procedure and produce further complications. Laparoscopic adhesiolysis decreases adhesion formation by minimizing manipulation of the abdominal organs.
Reducing the Risk
Vaginal delivery is the most effective means of reducing adhesion formation. Even after a c-section, some women can deliver later babies vaginally and avoid the increased risk of adhesion complications. Surgical techniques for c-sections that employ low incisions and minimal organ manipulation reduce the likelihood of adhesions.
Some obstetricians also place synthetic adhesion barriers, such as Seprafilm, between the uterus and the abdominal incision after completion of the delivery and repair of the uterus. In a 2009 article published in "Reviews in Obstetrics and Gynecology," the authors summarize the results from 13 trials of Seprafilm, noting a low incidence of complications and reduction of adhesion formation by as much as 90 percent. Use of Seprafilm specifically in women undergoing c-section reduced adhesion formation from 48 percent to 7.4 percent, compared to women in whom Seprafilm was not used.
- Reproductive Sciences: Postoperative Adhesion Development Following Cesarean and Open Intra-Abdominal Gynecological Operations
- British Medical Journal: Burden of Adhesions in Abdominal and Pelvic Surgery: Systematic Review and Metanalysis
- National Institutes of Health: NIH Consensus Development Conference Statement on Vaginal Birth After Cesarean -- New Insights
- Reviews in Obstetrics and Gynecology: Preventing Adhesions in Obstetric and Gynecologic Surgical Procedures