An evaluation of results of colon anastomosis in prepared and unprepared bowel.

Considerable controversy exists about the wisdom of primary anastomosis after resection of the unprepared right colon. We reviewed the records of 70 patients who had undergone colon resection with primary anastomosis in emergency and elective situations. One group consisted of 50 patients who underwent nonemergent colon resection after standard mechanical and antibiotic bowel preparation (prepared). The second group consisted of 20 patients who underwent resection of the right colon on an emergent basis without benefit of bowel preparation (unprepared). Risk factors (steroid dependence, peritonitis, previous radiation, diabetes mellitus, chronic renal failure) and complications were analyzed for each group. Statistical analysis demonstrated the following: (a) the incidence of total complications was greater in the unprepared group (p = 0.04), (b) there was an increased incidence of anastomotic disruption in the unprepared group (p = 0.02), and (c) a significant relationship existed (p = 0.005) between the presence of one or more risk factors and the development of complications after surgery in the unprepared group, indicating that in the absence of risk factors a successful outcome could be anticipated with primary anastomosis. Based on data from this study, our conclusions are twofold. First, in the presence of one or more risk factors, primary anastomosis after resection of unprepared right colon should not be attempted. Second, in any situation in which there are no risk factors, primary anastomosis of the unprepared right colon would be expected to achieve similar results as with prepared bowel.