Small-intestinal involvement in familial adenomatous polyposis: evaluation by double-balloon endoscopy and intraoperative enteroscopy

Background: Small-intestinal adenoma occurs in patients with familial adenomatous polyposis (FAP). Objectives: The aim was to analyze the diagnostic yield of a double-balloon endoscopy (DBE) and an intraoperative enteroscopy (IOE) for small-intestinal involvement in FAP. Patients: Forty-one patients with FAP. Interventions: We examined 12 patients with FAP by using oral DBE before a colectomy and 29 patients with FAP by using IOE. The incidence and the endoscopic findings of adenoma were compared between the 2 procedures. Phenotypes of FAP and genotypes of adenomatous polyposis coli (APC) were then compared between patients with small-intestinal adenomas and those without. The genotype was classified into a 5' mutation (exons 1-14), a 3' mutation (exon 15), and a negative mutation of APC. Main Outcome Measurement: The prevalence of adenoma. Results: A DBE detected small-intestinal adenomas in 9 of 12 patients (75%), as did an IOE in 15 of 29 patients (52%, P > .05). The adenomas occurred predominantly in the jejunum, with a configuration of diminutive polyps in 22 patients. In addition, a DBE detected nonpolypoid adenoma in a patient, and nodular, broad-based protrusion (advanced lesions) in 3 patients, whereas an IOE detected advanced lesions in a patient. Patients with small-intestinal adenoma had more severe duodenal adenomatosis than those patients without small-intestinal adenoma (P < .001). In cases in which APC was analyzed, the prevalence of small-intestinal adenoma was higher in patients with a 3' mutation (100%) than in those with a 5' mutation (44%) and with a negative mutation (42%, P < .02). Limitation: Not a prospective randomized study. Conclusions: A DBE is equal to an IOE for scrutiny of small-intestinal adenomas in FAP. There seems to be a genotype-jejunal phenotype correlation in FAP.