INTRODUCTION

Enterectomy is a common procedure used primarily for resection of small bowel or in combination with other gastrointestinal procedures. Enterectomy also is used in conjunction with reconstructive procedures for replacement of the gastrointestinal or urologic tract. This discussion focuses on primary enterectomy for treatment of small bowel conditions. The complications discussed here are common to those procedures requiring small bowel resection for other reasons.

Enterectomy has been part of the abdominal surgeons’ repertoire for much of the history of surgery, yet the risks and complications associated with this procedure have remained constant over its recent history. Whereas we may understand the pathophysiology and predisposing factors for their development, complications persist and all abdominal surgeons should be familiar with their development, consequences, repair, and prevention. This chapter focuses on these issues related to enterectomy.

The reported leak rates for intestinal anastomosis range from 1% to 8%.¹^–⁶ Specific leak rates for enterectomy are more difficult to find in the literature. One review reported a 1.1% leak rate in 798 patients undergoing enterectomy.⁷

The primary aspects necessary for construction of a successful anastomosis include careful approximation of wellvascularized bowel wall in a tension-free manner. Clearly, a technically inadequate anastomosis will lead to anastomotic failure.⁸ However, despite a technically suitable anastomosis, complications such as anastomotic failure can occur. Significant efforts have focused on understanding the nontechnical factors that contribute to anastomotic failure. Poor nutrition, hypoalbuminemia, infection, smoking, diabetes, obesity, and many others have been implicated in various studies.^1–4,^7,⁹^–¹¹ Despite extensive investigation, study results are conflicting and no consensus on predisposing factors has been reached. In Pickleman and coworkers’ review,⁷ the only factor predicting anastomotic leak after enterectomy was hypertension. How this contributed to anastomotic failure was unclear from this study. No differences were seen in stapled versus sewn anastomoses or between different types of anastomoses. Overall, their findings reinforced the concept that a clear set of factors predisposing to anastomotic leak have not been delineated.

INDICATIONS

• Small bowel obstruction

• Small bowel neoplasm

• Small bowel inflammatory disease (e.g., Crohn’s disease)

• Small bowel herniation with vascular compromise

• Enterocutaneous fistula

• Small bowel intussusception

• Mesenteric tumors when resection leads to small bowel ischemia

• Traumatic injury to the small bowel

OPERATIVE STEPS

Step 1 Incision

Step 2 Evaluation of small bowel from ligament of Treitz to ileocecal valve

Step 3 Identification of transection sites proximal and distal to diseased segment

Step 5 Assessment of anastomosis patency by palpation

Step 6 Suture closure of mesenteric defect

Step 7 Closure of incision

OPERATIVE PROCEDURE

Incision

Injuries upon Entry into the Peritoneal Cavity

All grades of injuries can occur during this step. This is primarily the case during reoperative surgery or during a primary procedure when the bowel is grossly dilated. Careful dissection and controlled entry into the peritoneal cavity under these conditions are required to avoid entry complications, as discussed in Section I, Chapters 6 and 7.

Evaluation of the Small Bowel

Identification of Transection Sites Proximal and Distal to the Diseased Segment

Missed or Recurrent Disease

The site chosen for transection of the small bowel is dependent upon the disease process being treated. Historically, a distance of 5 to 10 cm away from the lesion being resected has been advocated to ensure an adequate resection margin when treating a neoplasm. However, there does not appear to be literature providing solid evidence to support a specific transection distance. The transection site of the bowel is partly dictated by the amount of mesenteric resection necessary to encompass the lymphatic drainage in the area of the neoplasm. Transection for ischemic disease should be at sites that are well vascularized. Transection for inflammatory disease, such as Crohn’s disease, is done just outside the area of grossly involved bowel.

The consequences, repair, and prevention of this complication are similar to those in the prior section.

Creation of the Anastomosis

Several techniques are described for enterectomy with anastomosis. Currently, the most commonly practiced is a stapled side-to-side, functional end-to-end anastomosis. In some circumstances, this anastomosis is not technically feasible and a sewn anastomosis is required. The stapled anastomosis is used for illustrative purposes for this discussion, because the general complications for enterectomy with anastomosis are similar in both the stapled and the sewn techniques.

Injuries during Creation of a Mesenteric Defect

Injury to the small bowel or the adjacent mesentery can occur during this step.

• Consequence

Leakage of enteric contents, wound contamination, and increased postoperative infection risk. Mesenteric injury with bleeding, hematoma, or compromise of the blood supply to the remaining small bowel. Any of these injuries may lead to the unintended resection of additional normal small bowel.

Grade 1/2 complication

• Repair

The injured small bowel can be incorporated into the stapled transection line or the resection specimen. The mesenteric injury can be oversewn and/or incorporated into the resection specimen.

• Prevention

Transillumination of the mesentery (Fig. 21-2) will allow identification of the small mesenteric vessels and the edge of the bowel, thereby avoiding these injuries. Removing the lights from the operative field followed by direct light on the back side of the mesentery will allow the surgeon to identify these structures. The avascular window is then marked with cautery or punctured with a tonsil clamp to mark its position.

Prevention of infection is facilitated by covering the wound with a moist towel to keep the enteric contents from contaminating the edges (Fig. 21-3). The bowel involved in the anastomosis also can be surrounded by moist towels to contain any spillage of enteric contents. Milking enteric contents away from the transection sites (see Fig. 21-1) and occluding the bowel proximally and distally with a noncrushing bowel clamp (Fig. 21-4) will minimize enteric contents in the enterectomy site. Placement of the occluding clamp should be done in a fashion that does not include the mesentery. Finally, administration of perioperative antibiotics, covering gram-negative bacilli and anaerobes, will minimize the risk of perioperative infections.