ENDOSONOGRAPHIC EVIDENCE OF INJURY TO THE INTERNAL ANAL-SPHINCTER AFTER LOW ANTERIOR RESECTION - LONG-TERM FOLLOW-UP

PURPOSE: Transanal stapled anastomosis has been associated with contin ence disturbances and reduced postoperative anal sphincter function. T he aim of the present work was to study the effect of transanal stapli ng on anal sphincter morphology by endoanal ultrasound. METHODS: Thirt y-nine consecutive patients undergoing stapled Iom anterior resection for rectal carcinoma were assessed. Each patient was assessed by endol uminal ultrasound before surgery, immediately after surgery, and at 3, 6, 9, 12, and 24 months after surgery. RESULTS: There were no preoper ative internal anal sphincter defects observed. Three female patients were observed to have preoperative evidence of external anal sphincter defects. Alter low anterior resection, seven patients were found to h ave internal anal sphincter defects, which persisted after the two-yea r follow-up. There were no additional external anal sphincter injuries . Three patients with internal anal sphincter injuries required the us e of pads for poor bowel function. CONCLUSIONS: Up to 18 percent of pa tients who underwent stapled low anterior resection had long-term evid ence of internal anal sphincter injury. The external sphincter does no t appear to be affected by the procedure.