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

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.

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.

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.

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.

The study was registered at ClinicalTrials.gov (NCT03534596, retrospectively registered, 2018-05-24).