Endosonographic evidence of injury to the internal anal sphincter after low anterior resection: long-term follow-up.
OBJECTIVE
Transanal stapled anastomosis has been associated with continence disturbances and reduced postoperative anal sphincter function. The aim of the present work was to study the effect of transanal stapling on anal sphincter morphology by endoanal ultrasound.


METHODS
Thirty-nine consecutive patients undergoing stapled low anterior resection for rectal carcinoma were assessed. Each patient was assessed by endoluminal ultrasound before surgery, immediately after surgery, and at 3, 6, 9, 12, and 24 months after surgery.


RESULTS
There were no preoperative internal anal sphincter defects observed. Three female patients were observed to have preoperative evidence of external anal sphincter defects. After low anterior resection, seven patients were found to have internal anal sphincter defects, which persisted after the two-year follow-up. There were no additional external anal sphincter injuries. Three patients with internal anal sphincter injuries required the use of pads for poor bowel function.


CONCLUSIONS
Up to 18 percent of patients who underwent stapled low anterior resection had long-term evidence of internal anal sphincter injury. The external sphincter does not appear to be affected by the procedure.
Academic Surgical Unit, University of Hull, Castle Hill Hospital, East Yorkshire, United Kingdom.
R
R
Farouk
G S
GS
Duthie
P W
PW
Lee
J R
JR
Monson
D001003:Anal Canal / Q000000981:diagnostic imaging* / Q000293:injuries*; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000601:surgery*; D017792:Surgical Stapling; D016896:Treatment Outcome