OBJECTIVETo introduce the diagnosis and the treatment of the long-segment bowel stenosis above the anastomosis and bowel obstruction caused by the radiation-induced pelvic wall and bowel fibrosis.

METHODSBetween January 2008 and June 2014, 468 patients with rectal carcinoma underwent sphincter-preserving operation after neoadjuvant chemoradiotherapy in Fujian Medical University Union Hospital. Among 241 patients without postoperative anastomotic leakage, anastomosis stenosis, local recurrence and small bowel obstruction, severe pelvic and bowel fibrosis with obstruction during follow-up was found in 14 patients(SFO group). Associated data of these 14 patients were retrospectively collected. Clinical and image characteristics, and treatment outcomes of these 14 patients were analyzed and compared to those of other 227 patients without fibrosis and obstruction (control group).

RESULTSCompared to control group, SFO group had lower BMI(19.7±2.3 vs. 22.5±3.2, P=0.000), higher ratio of male (92.9% vs. 63.9%, P=0.039) and smoking patients(78.6% vs. 32.2%, P=0.001), shorter preoperative distance from lower edge of tumor to anal verge [(4.9±0.7) cm vs. (5.7±1.4) cm, P=0.043), and longer time from the end of radiation to operation [(9.4±2.3) week vs. (8.1±1.7) week, P=0.024). The largest thickness of the bilateral obturator internus increased significantly after chemoradiotherapy (left side: P=0.030, right side: P=0.020) as compared to pre-chemoradiotherapy on MR image. Patients of SFO group received corresponding treatments according to the status of bowel stricture, and the outcomes were all satisfactory.

CONCLUSIONSReconstructed rectum stricture can be caused by the radiation-induced fibrosis of pelvic wall soft tissue and proximal colon. Severe stricture can be treated with corresponding methods to relieve symptoms.