Avoiding and repairing bowel injury in gynecologic surgery
Tips for avoiding the pitfalls in at-risk patients and injury-prone procedures, plus techniques for adhesiolysis, repair of serosal and small bowel injuries, and inspection of the bowel to rule out perforations.
- Although the optimal method is a matter of choice, preoperative bowel preparation is recommended to reduce bacteria, stool bulk, and infectious complications.
- When entering the peritoneal cavity in patients with prior surgery, watch for adhesions between a loop of bowel and the abdominal wall.
- In high-risk patients, enter the peritoneal cavity by extending the previous abdominal scar superiorly and inferiorly to minimize risk of injury.
- Close small perforations in 2 layers, with the suture line always perpendicular to the long axis of the bowel.
- For more extensive injury or compromised blood supply to the bowel wall, resection and anastomosis may be necessary. Obtain intraoperative general surgical consultation if not trained to perform this kind of repair.
This dreaded complication requires vigilance and skill to avoid, and adequate training and experience to manage and repair. In a perfect world, every gynecologist would be trained in techniques to prevent and repair inadvertent bowel injuries. Unfortunately, residency programs often do not provide such training.
Gynecologists routinely operate on patients with risk factors for bowel injury—obesity, endometriosis, multiple abdominal procedures, pelvic inflammatory disease, history of malignancy, and advanced age. A general surgeon is often called, however, for bowel repairs that can be performed by a gynecologist with sufficient training and experience. (There are instances, however, in which a general surgical consultation may not be readily available—another reason to master repair of bowel injuries encountered during gynecologic surgery.)
This article describes techniques to avert and manage intestinal injury. Topics include adhesiolysis, repair of bowel perforations, segmental bowel resection, and pre- and postoperative management. Vascular anatomy of the bowel is illustrated.
We emphasize the need for direct supervision by an experienced surgeon while mastering these techniques.
Bowel preparation: A useful tool to reduce infection, leakage
Isolated reports have questioned the need for mechanical bowel preparation, 1,2 and some experts point to the recent success of primary repairs of gunshot and stab wounds to the colon as evidence that bowel preparation and preoperative oral antibiotics are unnecessary.
Other studies indicate potential benefits, namely reducing infectious complications and anastomotic leakage following repair of inadvertent enterotomy. Indeed, the vast majority of North American surgeons continue to use some form of bowel preparation,3,4 and it is the standard of care for elective intestinal surgery. For these reasons, bowel preparation is strongly encouraged for the gynecologic surgeon operating on a pelvic mass, endometriosis, or malignancy, or when difficult dissection is anticipated with the potential for inadvertent enterotomy and spillage of intestinal contents.
Bowel preparation consists of 2 phases: mechanical cleansing and antibiotic administration (TABLE). The postoperative infection rate can be reduced to well below 10% when these are properly performed.
Mechanical cleansing reduces the bulk of stool content within the lumen of the bowel, which also decreases the absolute amount of bacteria.5 Anaerobes are the predominant flora in the colon, with an estimated density of 1010 organisms per gram of stool. Perforation and spillage of colon contents contaminates the peritoneal cavity with more than 400 species of bacteria.
Perforation and spillage of colon contents contaminates the peritoneal cavity with more than 400 species of bacteria.
In the past, stool bulk was reduced via a low-residue or liquid diet combined with cathartics, enemas, or other agents given over 2 to 3 days. This regimen was time-consuming, patient compliance was poor, and nutritional intake was severely restricted prior to major surgery.
Today, polyethylene glycol and sodium phosphate are the 2 most popular methods of bowel preparation.
- Polyethylene glycol (Golytely, Braintree Labs, Braintree, Mass) is a balanced electrolyte solution dispensed in a 4-L quantity that must be taken over 4 hours. Some patients find this volume difficult to consume; one option is administering the solution via a small nasogastric tube. Complications may include nausea/vomiting, abdominal cramping, and, rarely, fluid overload and electrolyte disturbances.
- Sodium phosphate (Fleet Phosphosoda, C.B. Fleet Co, Lynchburg, Va) is administered in two 45-mL increments several hours apart. There is no consensus on which bowel-prep method is superior3,4; most surgeons prefer one or the other. Due to potential electrolyte abnormalities with the use of sodium phosphate, polyethylene glycol is favored for patients with significant renal, cardiac, or hepatic disease.
- We recommend minimally absorbed oral antibiotics (1 g each of neomycin and erythromycin, given at 1 PM, 2 PM, and 11 PM the day before surgery) in combination with an intravenous second-generation cephalosporin (1 g if using cefotetan, 2 g if using cefoxitin; given immediately before surgery and continued postoperatively for 3 doses).
- Timing of antibiotic administration is important, since postoperative antibiotics alone do not appear to be effective. If significant spillage occurs intraoperatively, parenteral antibiotics should be continued for 5 days.
Bowel prep regimen
DAY BEFORE SURGERY
Polyethylene glycol, 4L, to be consumed over 4 to 6 hours
Neomycin, 1 g orally
Erythromycin, 1 g orally
Neomycin, 1 g orally
Erythromycin, 1 g orally
Neomycin, 1 g orally
Erythromycin, 1 g orally
DAY OF SURGERY
Intravenous cephalosporin (1 g cefotetan or 2 g cefoxitin); 1 hour before incision, continued postoperatively for 3 doses
Thermal injury due to unipolar cautery is particularly ominous because the extent of injury exceeds what is grossly observed.
When injuries are most likely
Intestinal injuries during gynecologic surgery usually involve the small bowel and can be minor, such as a serosal tear or a small, full-thickness laceration—or major, involving a devitalized bowel loop or its mesentery.
Bowel injury may occur during a variety of surgical procedures. One study showed that most injuries occur during adhesiolysis or entry into the peritoneal cavity. A smaller but substantial number of cases occur during “less extensive” procedures such as uterine curettage and laparoscopy.6
Upon entering the peritoneal cavity, keep in mind the possibility of injuring an adherent loop of bowel. Because of its anatomical relationships to the pelvic viscera, portions of the bowel may become involved in adhesions, which can lead to extremely challenging pelvic dissections in conditions such as endometriosis or severe pelvic infection. Dissection of pelvic adhesions is a common cause of bowel injury, because bowel loops are retracted deeply downward by adhesive bands, and the limited pelvic space hampers visualization and gentle adhesiolysis.
At special risk for bowel injury are women who have undergone prior abdominal operations or who are obese. In a series of 270 general surgery patients undergoing reoperation, 7 52 (19%) sustained inadvertent enterotomy. These patients had undergone a mean of 3.3 previous laparotomies and had a higher body mass index (mean of 25.5 versus 21.9).
Age may be another risk factor, since patients with enterotomies were 60 years or older.7
Injury during laparoscopy. Inadvertent bowel injuries may occur during laparoscopic procedures, especially at the time of trocar insertion or manipulation of pelvic structures. 5 One device that helps prevent these injuries is the optical trocar (Visiport, US Surgical, Norwalk, Conn), which allows physicians to visualize the layers of the abdominal wall as penetration occurs.
We also routinely direct anesthesia personnel to insert a nasogastric tube at the beginning of laparoscopic procedures to facilitate decompression of the stomach and small bowel.
The risks of electrosurgery. Electrocautery used for tubal ligation, pelvic dissection, or hemostasis may injure the bowel if the surgeon is not careful. Thermal injury due to unipolar cautery is particularly ominous because the extent of injury is greater than what can be grossly observed. The incidence of this type of injury can be reduced using bipolar cautery devices, as well as clips or bands for tubal ligation.
Injury as a result of uterine perforation is unlikely, but can occur. If perforation occurs during dilation and curettage, bowel laceration may result, particularly adhesions are present between the uterus and bowel loops. In extremely rare instances, a loop of bowel may be pulled through a perforation into the uterine cavity or vagina, requiring laparotomy for reduction and repair. Caution is advised during curettage, especially in a gravid uterus, to prevent this potentially catastrophic event.
Avoid the temptation to lyse opaque adhesions using blunt dissection, as serosal tears and enterotomies may occur.
Adhesiolysis: Plan on a lengthy, meticulous procedure
Adhesions are a common cause of pelvic pain, infertility, and bowel obstruction, and their presence may make it difficult to carry out the intended surgical procedure. Adhesiolysis may be necessary to mobilize loops of bowel tightly adherent to pelvic structures, to provide sufficient exposure of the surgical field and prevent subsequent bowel obstruction.
The extent of adhesions does not necessarily correlate with clinical symptoms.
Adhesions may be of the thin, filmy, “friendly” variety or dense, thick bands.
How adhesions occur. When tissue is injured, fibrin is deposited on the peritoneal and serosal surfaces. The extent to which this fibrin is infiltrated with fibroblasts and the degree of subsequent fibrosis determine adhesion density. Any process that impairs fibrinolysis tends to delay resolution of adhesions.
Contributing factors. Adhesions are commonly encountered in pelvic surgery and may be observed in 50% to 90% of patients who have undergone previous surgery.8
Obese patients also are more susceptible to adhesions. Other contributing factors include pelvic infection, bleeding, irradiation, chemical irritants, and conditions such as endometriosis.
Lysis technique. Apply gentle, controlled traction—as well as countertraction—on the bowel loops to facilitate isolation and dissection with sharp Metzenbaum scissors or a scalpel. (Forceful traction or rough handling of bowel loops may cause a breach in the bowel wall with subsequent spillage of intestinal contents.)
Avoid the temptation to lyse adhesions using blunt dissection (serosal tears and enterotomies may occur)—except in the case of translucent adhesions. These may be lysed via gentle, blunt dissection by rubbing the index finger and thumb back and forth over tissue. They also may be sharply cut using the tip of the scissors to form a “window” in a portion of the adhesion and cutting the adhesive segments in increments.
A characteristic line of demarcation often appears between adhesions and their peritoneal attachment, denoting a safe dissection plane.
Technique for special challenges: Chronic pelvic disease, prior laparotomies. When operating on these patients, be prepared for a long, meticulous procedure. A hasty approach in such cases is perilous and increases the likelihood of postoperative complications.
First, dissect the anterior abdominal wall from the adherent bowel on either side of the incision. Then extend the dissection laterally on both sides until the ascending and descending colon are identified. Next, dissect the small bowel free and mobilize it out of the pelvis.
It often is helpful to move to another area when dissection becomes too difficult; dissection through easier planes often will clarify the relationship of pelvic structures and adherent bowel loops.
Once the small bowel has been mobilized from the pelvis, lyse adhesions between loops of bowel that are causing kinking or narrowing of the lumen, to reduce the risk of postoperative bowel obstruction. Next, carefully dissect pelvic structures from the sigmoid colon and rectum.
How and when to repair serosal injury
Serosal injury is a breach of integrity of the visceral peritoneum, the outermost covering of the bowel wall. This may occur when the serosa is cut during entry into the abdomen or when it is torn during blunt dissection of dense adhesions.
If the underlying muscular and mucosal layers remain intact, these small areas of “denuded” serosa need not be repaired, since most experts believe that suture placement increases the likelihood of future adhesions. The serosal and muscular layers should be repaired if the mucosa is exposed, however. Otherwise the bowel wall will weaken at the site, making it vulnerable to perforation. The seromuscular layers can be approximated easily using interrupted 4-0 silk on a small tapered needle. Be careful to avoid placing the stitch through the mucosa, which would violate the bowel lumen.
When the defect of the seromuscular layer is large (when a more extensive area is denuded during dissection of densely adherent bowel away from a tumor or endometriotic lesion), repair becomes more involved. This may require resection of the injured area with primary anastomosis.