Small bowel motility and transit after aortic surgery

Objective: The inability to tolerate feedings after aortic surgery prolongs hospitalization. The aim of this study was to define jejunal manometric and small bowel transit characteristics associated with the ileus that follows transperitoneal aortic surgery. Methods. Five mate patients who underwent transperitoneal infrarenal aortobifemoral bypass had intraopevative placement of a jejunal multilumen catheter. The open abdomen allowed precise placement of pressure recording ports at 20, 22, 24, 26, 28, and 38 cm past the ligament of Treitz. Three-hour manometric studies were done after surgery and for 3 postoperative days. The migrating motor complex was identified visually on the manometric tracings, and pressure waves were identified with computer and a motility index calculated, Motility data were compared with healthy control data previously reported in the literature. Small bowel transit was determined with barium and serial abdominal radiographs. Results. All patients had ileus develop with return of bowel sounds at 2 to 7 days (median, 6 days) and flatus at 3 to 9 days (median, 7 days) after surgery. Jejunal motor activity was present within 6 hours of surgery, but the motility index was less in patients then in control subjects. The postoperative migrating motor complexes differed from control subjects in having more phase I, less phase II, and more frequent phase IIIs. Phase III retrograde migration was common in the patients but not in the control subjects. Small bowel transit was 2 days or greater in all patients. Conclusion: Motor activity is present in the jejunum shortly after aortic surgery. However, the activity is decreased in intensity and the fasting cycle differs from control subjects. Retrograde migration of phase III is the most likely abnormality, resulting in delayed small bowel transit. The data would predict a high rate of enteral feeding intolerance early after surgery. Future studies should focus on pharmacologic manipulation to rapidly return small bowel motility to a more normal state after aortic surgery.