RESUMO
BACKGROUND: The major causes of small bowel obstruction (SBO) are postoperative adhesion, hernia, intussusception and malignancies. However, in cases of uncommon causes of SBO, surgeons are be in a dilemma because the preoperative diagnosis and the decision to operate are frequently difficult and delayed. METHODS: We reviewed retrospectively the cases of 29 patients with SBO who were operated on for unknown etiology at Daedong Hospital between Jan. 1, 1991, and Dec. 31, 1997. The common causes of SBO, such as postoperative adhesion, external hernia, congenital anomaly of the gastrointestinal tract in neonate, intussusception in children, and known intraabdominal malignancy, were all excluded. RESULTS: 1) The incidence of uncommon causes of SBO included in this study was 8.7% of all cases of SBO operated on during the same period. 2) Among the 29 cases, 12 cases were caused by tumors (41.4%), of which the number of malignant tumors was double that of benign ones. 3) Besides tumors, there were 3 cases of bezoar, two cases of congenital bands, mesenteric cysts, internal hernias, Meckel's diverticula, and intussusception, one case each of mesenteric panniculitis and Crohn's disease, and two cases with an unknown etiology of inflammation. 4) Five cases were due to adult intussusception, 3 cases of which were due to benign tumors of the small bowel. All of the SBOs by intussusception were located at the terminal ileum. 5) The most common site of obstruction was the ileum (20 cases), followed by the jejunum (7 cases), and the duodenum (2 cases). 6) Males were dominant (1.6:1) especially in cases of tumor-origin SBOs (2:1). 7) In viewing the age distribution, the incidence was relatively high in the 5th and the 8th decades. Especially, tumor-origin SBOs had their peak in the 5th decade, and all cases of bezoar were found in 8th decade. 8) Operations were performed within 72 hours in 19 cases (65.5%) after first inspection of the patients, and intussusception, congenital band, and bezoar were the common causes of the cases involved in early surgical intervention. 9) Segmental resection of the small bowel was the most common surgical procedure (19 cases, 65.5%), followed by bypass surgery (6 cases), removal of the bezoar (2 cases), and excision of the mesenteric cyst or band (1 case, respectively). Coclusions: We think it reasonable to perform an exploratory laparotomy in cases of unknown causes of SBO as early as possible because almost all the cases require surgical intervention eventually, and studies searching for the causes of obstruction will only be time-consuming. While surgeons should keep in mind that tumors are major causes of uncommon SBOs.