Colon/Small Bowel
Subject Category: Colon/Small Bowel
Am J Gastroenterol 2009; 104:133–141; doi:10.1038/ajg.2008.2
Neorectal Irritability After Short-Term Preoperative Radiotherapy and Surgical Resection for Rectal Cancer
Roel Bakx MD1,4, Annemiek Doeksen MD1,4, J Frederik M Slors MD1, Willem A Bemelman MD1, J Jan B van Lanschot MD1,5 and Guy E E Boeckxstaens MD2,3
- 1Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands
- 2Department of Gastroenterology, Academic Medical Center, Amsterdam, The Netherlands
- 3Department of Gastroenterology, University Hospital Leuven, Catholic University of Leuven, Leuven, Belgium
Correspondence: Guy E.E. Boeckxstaens, MD, Department of Gastroenterology, University Hospital Leuven, Catholic University of Leuven, Herestraat 49, Leuven 3000, Belgium. E-mail: guy.boeckxstaens@med.kuleuven.be
4These authors contributed equally to the article
5Present address: Erasmus Medical Center, Rotterdam, The Netherlands
Received 22 March 2007; Accepted 19 July 2008.
Abstract
OBJECTIVES:
Preoperative radiotherapy followed by rectal resection with total mesorectal excision (TME) and colo-anal anastomosis severely compromises anorectal function, which has been attributed to a decrease in neorectal capacity and neorectal compliance. However, to what extent altered motility of the neorectum is involved, is still unknown. The aim of the study was to compare the motor response to (prolonged) filling of the (neo-)rectum in patients after preoperative radiotherapy and rectal resection with that in healthy volunteers (HV).
METHODS:
Neorectal function (J-pouch or side-to-end anastomosis) was studied in 15 patients (median age 61 years, 10 males) 5 months after short-term preoperative radiotherapy (5
5 Gy) and rectal resection with TME for rectal cancer and compared with that of 10 volunteers (median age 41 years, 7 males). Furthermore, patients with a colonic J-pouch anastomosis (n=6) were compared with patients with a side-to-end anastomosis (n=9). (Neo-)rectal sensitivity was assessed using a stepwise isovolumetric and isobaric distension protocol. (Neo-)rectal motility was determined during prolonged distension at the threshold of the urge to defecate.
RESULTS:
The neorectal volume of patients at the threshold of the urge to defecate (125 
45 ml) was significantly lower when compared with that of HV (27287 ml, P<0.05). The pressure threshold, however, did not differ between patients (269 mm Hg) and HV (215 mm Hg) and neither did the pressure threshold differ between patients with a J-pouch and those with side-to-end anastomosis. In HV, no rectal contractions were observed during prolonged rectal distension. In contrast, in all 15 patients, prolonged isovolumetric and isobaric distension induced 3 (range 0–5) rectal contractions/10 min, which were associated with an increase in sensation in half of the patients.
CONCLUSIONS:
Patients who underwent preoperative radiotherapy and rectal resection with TME, but not HV, developed contractions of the neo-rectum in response to prolonged distension. We suggest that this neorectal "irritability" represents a new pathophysiological mechanism contributing to the urgency for defecation after this multimodality treatment.
