Abstracts of the 9th Annual Scientific Meeting of the Hong Kong Society for Coloproctology 27 January 2007: 1 ADJUVANT RADIOTHERAPY IS AN INDEPENDENT RISK FACTOR FOR SMALL BOWEL OBSTRUCTION AFTER CURATIVE RECTAL CANCER SURGERY

Small bowel obstruction (SBO) as a complication is not uncommon after curative rectal cancer surgery; adjuvant radiotherapy (RT) may have a contributory role. This study aimed at determining the prevalence and risk factors for this complication. The medical records of 260 consecutive patients with rectal cancer (excluding rectosigmoid cancer) who underwent curative surgery at our institution between January 1995 and December 2000 were retrospectively reviewed to determine the prevalence of SBO requiring hospitalization and intervention. Possible risk factors for SBO were recorded and analysed using univariate and multivariate analysis. The median duration of follow up was 76.1 months (range, 3.3-141.8 months). Forty-four patients (16.9%) developed SBO and 19 of them required surgical intervention. Three patients (6.8%) died as a consequence of SBO. Seventy-eight patients (30%) received adjuvant RT with a median dose of 50 Gy (range 30-64 Gy). Patients receiving RT were more likely to develop SBO (25.6% vs 13.2%, P = 0.014). The median duration between adjuvant RT and the first episode of SBO was 23.5 months (range, 5.7-99.4 months). Multivariate analysis showed that adjuvant RT was the only independent risk factor for SBO (OR = 2.27, 95% CI = 1.17-4.42, P = 0.016). Gender, operative approach (open vs laparoscopic), abdominoperineal resection, perioperative blood transfusion, postoperative intra-abdominal sepsis, tumour stage, and disease recurrence were not associated with the development of SBO. Adjuvant RT is the only independent risk factor for SBO after curative surgery for rectal cancer. Patients should be well informed of this potential complication when they are offered adjuvant RT.