title: Quantitative short-term study of anal sphincter function after chemoradiation for rectal cancer.
abstract: OBJECTIVE
  Pelvic irradiation adversely affects anal sphincter function after proctectomy with coloanal anastomosis for low rectal and middle rectal (<10 cm from the anal verge) tumors.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Private, tertiary care referral center.
  
  
  METHODS
  Patients treated for low rectal adenocarcinoma between January 1, 1994, and October 31, 1999.
  
  
  METHODS
  Anal manometric data were prospectively collected at the time of initial diagnosis and before ileostomy closure.
  
  
  METHODS
  Mean and maximum resting pressures (RPs) and squeeze pressures, threshold volume for sensation, and maximal tolerable volume.
  
  
  RESULTS
  Twenty-three patients in the surgery group and 19 in the chemoradiotherapy group were considered for analysis; 15 patients had preoperative radiotherapy and 4 had postoperative radiotherapy. At the time of ileostomy closure, RPs were significantly lower in the chemoradiotherapy group than in the surgery group (32.7 +/- 17 vs 45.3 +/- 18 mm Hg; P =.03). Squeeze pressures were not significantly different between the surgery and chemoradiotherapy groups (108.7 +/- 56.7 vs 102.0 +/- 52.6 mm Hg; P =.69). The ratios of postresection to preresection RPs were also significantly lower in the chemoradiotherapy group (0.49 +/- 0.29) than in the surgery group (0.76 +/- 0.22) (P =.005). Eight to 12 weeks after proctectomy with coloanal anastomosis, a 24% decrease in RP was noted in the surgery group. The addition of adjuvant pelvic irradiation decreased RP by another 27%.
  
  
  CONCLUSIONS
  Adequate shielding of the anal sphincter should be performed for low rectal cancers whenever a sphincter-preserving procedure is considered.
authors.affiliation: Department of Colon and Rectal Surgery, Cleveland Clinic Florida, 3000 W Cypress Creek Rd, Fort Lauderdale, FL 33309, USA.
authors.forename: P
authors.initials: P
authors.lastname: Gervaz
authors.forename: N
authors.initials: N
authors.lastname: Rotholtz
authors.forename: M
authors.initials: M
authors.lastname: Pisano
authors.forename: E
authors.initials: E
authors.lastname: Kaplan
authors.forename: M
authors.initials: M
authors.lastname: Secic
authors.forename: P
authors.initials: P
authors.lastname: Coucke
authors.forename: A
authors.initials: A
authors.lastname: Pikarsky
authors.forename: J
authors.initials: J
authors.lastname: Efron
authors.forename: E
authors.initials: E
authors.lastname: Weiss
authors.forename: S
authors.initials: S
authors.lastname: Wexner
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000503:physiopathology* / Q000532:radiotherapy / Q000601:surgery; D000368:Aged; D001003:Anal Canal / Q000503:physiopathology*; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D016022:Case-Control Studies; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008365:Manometry; D011882:Radiotherapy, High-Energy; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000503:physiopathology* / Q000532:radiotherapy / Q000601:surgery
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil