Small bowel obStruction: the eternal dilemma of when to intervene

obstruction is the most common disorder afflicting the small bowel. the days of not letting the sun set on a small bowel obstruction (SBo) perhaps allowed for less complex surgical decision-making algorithms than to watchfully wait and wonder about the state of the bowel. this old surgical adage seems to have lost its reverence with time. the caveat is that the current diagnostic armamentarium in predicting nonoperative failures remains far from foolproof. the fundamental clinical shortcoming is the clinicians’ inability to definitively predict cases of small bowel obstruction destined to evolve into strangulated bowel if left to nonoperative measures. Prospective, randomized studies addressing operative timing for small bowel obstruction do not exist. As such, the definitive answer to the dilemma in this article’s title will not be unraveled in the immediate future. the majority (75%) of small bowel obstructions are attributed to intraabdominal adhesions from prior operations. the rate of adhesive SBo development is highest in the first few postoperative years following the index operation, particularly after colorectal surgery, but the risk remains life-long (4). At 10 years, recurrent obstruction from adhesions is estimated to occur 15 to 50% of the time. Amongst patients with adhesive obstruction, anywhere from 25 to 66% are reported to require an operation (3, 12, 13, 17, 20). SBo cases attributed to hernias have been on the decline over the past few decades, from 40% in the 1960s to 15%, presumably due to an increased rate of elective hernia repair (4, 11). With this declining trend, inflammatory bowel disease is now considered one of the leading causes of SBo in the Western world (15, 18). In patients without previous operations or hernias, cancer accounts for half of small bowel obstructions. otherwise, it comprises 5–10% of cases (4). In the first three or so decades of the 20th century, mortality from small bowel obstruction was as high as 60% (19). In more contemporary series, the reported mortality rate is 3–7% in uncomplicated cases, rising to above 15% in the presence of strangulation (7, 11, 13). Factors shown to potentiate mortality risk include older age and presence of comorbidities (7, 17). A prospective study of Veterans Affairs Medical Center patients identified dirty or infected wounds, ASA class ≥ 4, age > 80 years, and dyspnea at rest to increase odds of death (17). Fevang et al. identified old age, comorbidities, nonviable strangulation, and treatment delay > 24 hours to increase mortality rate (11). Similarly, Duron et. al. reported age > 75 years and ASA class III as independent risk factors for increased early mortality (7). In a longitudinal, population-based review of more than 32,000 patients treated for SBo, 24% of whom required surgery on initial admission, length of stay was longer for those undergoing operations, but mortality was lower, readmissions for SBo fewer, and time to obstructive readmission longer (13). others have found increased morbidity with factors such as small bowel resection (compared to adhesiolysis alone), old age, comorbidities, treatment delay > 24 hours, and need for repeat surgery (11, 17, 20).