title: Poor neorectal evacuation as a cause of impaired defecatory function after low anterior resection: a study using scintigraphic assessment.
abstract: OBJECTIVE
  Patients who have undergone low anterior resection (LAR) of the rectum occasionally complain of symptoms related to impaired neorectal evacuation. Using scintigraphy, we assessed neorectal evacuation in 22 patients who underwent LAR and straight anastomosis, and correlated the results with clinical defecatory function, clinical factors, and anorectal manovolumetric parameters.
  
  
  METHODS
  After the introduction of an artificial stool containing 99mTc-DTPA into the neorectum, sequential lateral gamma images were obtained. From the time-activity curve of radioactivity in the whole pelvis, the time taken to evacuate half of the introduced artificial stool (T(1/2)) and the percentage of artificial stool evacuated in 1 min (Evac1) were calculated.
  
  
  RESULTS
  The Evac1 was significantly lower in the patients who had undergone LAR than in reference normal volunteers. A long T(1/2) was significantly associated with worse defecatory function. The Evac1 was also significantly lower in patients with a low anastomosis. The rectal sensory threshold was significantly greater in patients with a shorter T(1/2). The maximum tolerable volume of the neorectum was significantly greater in patients with a shorter T(1/2) and a higher Evac1.
  
  
  CONCLUSIONS
  Poor neorectal evacuation is associated with impaired defecatory function after LAR. Therefore, it is suggested that optimizing both reservoir function and evacuation of the neorectum would improve defecatory function after LAR.
authors: Department of Surgery, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan.
authors: Masatoshi
authors: M
authors: Oya
authors: Yoshitake
authors: Y
authors: Sugamata
authors: Junji
authors: J
authors: Komatsu
authors: Hiroshi
authors: H
authors: Ishikawa
authors: Miwako
authors: M
authors: Nozaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003672:Defecation / Q000502:physiology*; D005260:Female; D005769:Gastrointestinal Motility; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid