Risk Factors for the Development of Adhesive Small Bowel Obstruction after Abdominal and Pelvic Operations

Introduction: Adhesive small bowel obstruction (SBO) is a disease process that has been difficult to prevent. Mechanical barriers and chemical agents exist to disrupt the formation of adhesions following surgery but each associated with medical risk and financial burden. Identifying risk factors for developing SBO in patients post laparotomy would aid in the appropriate use of such agents. We hypothesize that there might be additional risk factors that are associated with a higher likelihood of SBO. Methods: A retrospective analysis from 2008 to 2012 was performed. Cases of SBO following previous laparotomy were compared to those without SBO. Results: 468 medical records were reviewed (57% male). Operations that caused the highest risks for SBO included gynecological, colorectal and hernia operations with prosthetic materials. 66% percent of patients underwent a prior abdominal or pelvic high-risk procedure. The average time from surgery to the development of SBO was 24 months (median 19 months). Patients who developed SBO had a median age of 58.4 years on initial surgery, average previous operative time of 4.3 hours, and an average of two prior operations. For every hour of operative time, the odds of developing SBO increased by 33% (p < 0.05) and for every prior surgery, the odds increased by 24% (p < 0.05). The presence of ASA Classification > 3 decreased the odds of SBO (p = 0.05). Conclusions: Longer operative times are associated with post-operative adhesive small bowel obstruction. Patients with an ASA score greater than or equal to 3 appear to have a reduced risk of adhesive small bowel obstruction.