Mechanisms of adhesive small bowel obstruction and outcome of surgery; a population-based study

BACKGROUND: This study aims to describe the mechanisms of adhesive small bowel obstruction (SBO) and its morbidity, mortality and recurrence after surgery for SBO in a defined population. METHOD: Retrospective study of 402 patients (240 women, median age 70 years, range 18–97) who underwent surgery for SBO in the Uppsala and Gävleborg regions in 2007–2012. Patients were followed to last note in medical records or death. RESULT: The cause of obstruction was a fibrous band in 56% and diffuse adhesions in 44%. Early overall postoperative morbidity was 48 and 10% required a re-operation. Complications, intensive care and early mortality (n = 21, 5.2%) were related to age (p < 0.05) and American Society of Anesthesiologist’s class (p < 0.01). At a median follow-up of 66 months (0–122), 72 patients (18%) had been re-admitted because of SBO; 26 of them underwent a re-operation. Previous laparotomies (p = 0.013), diffuse adhesions (p = 0.050), and difficult surgery (bowel injury, operation time and bleeding, p = 0.034–0.003) related to recurrent SBO. The cohort spent 6735 days in hospital due to SBO; 772 of these days were due to recurrent SBO. In all, 61% of the cohort was alive at last follow-up. Late mortality was related to malignancies, cardiovascular disease, and other chronic diseases. CONCLUSIONS: About half of patients with SBO are elderly with co-morbidities which predispose to postoperative complications and mortality. Diffuse adhesions, which make surgery difficult, were common and related to future SBO. Overall, nearly one-fifth of patients needed re-admission for recurrent SBO. Continued research for preventing SBO is desirable. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT03534596, retrospectively registered, 2018-05-24).