Decreased interstitial cells of Cajal in the neorectum after anterior resection of the rectum

Background/Aims: Patients who have undergone anterior resection for rectal carcinoma often complain of anorectal and defecatory dysfunction postoperatively. The aim of this study was to examine the expression of interstitial cells of Cajal (ICCs) in the sigmoid colon used for constructing the neorectum after anterior resection of the rectum. Methodology: As the neorectum group, we assessed 12 patients with local and anastomotic recurrence or new neoplasm in the neorectum after anterior resection of the rectum. The control group consisted of 16 patients who underwent sigmoid colon resection for sigmoid colon carcinoma. All resected. specimens were investigated with immunohistochemical staining, using c-kit antibody for ICCs. The correlation between the number of ICCs and defecatory symptoms was assessed for the neorectum. Results: The total number of ICCs significantly decreased in the neorectum group as compared to the control group. In particular, a significant difference was noted between the two groups as to the number of ICCs found between the layers of the myenteric plexus in histological studies, as well as in the circular and longitudinal muscles. There was no correlation between the number of ICCs and the time interval from the initial anterior resection to the resection of the neorectum, nor was there any relationship between the number of ICCs and defecatory symptoms. Conclusions: The expression of ICCs in the neorectum was reduced in the early stages after anterior resection of the rectum. Expression of ICCs in the neorectum did not recover to preoperative levels over time.