title: Anal Function after Surgery for Low-Lying Rectal Cancer: Comparison of Mechanical and Hand-Sewn Coloanal Anastomosis.
abstract: OBJECTIVE
  Mechanical coloanal anastomosis (MCAA) or hand-sewn coloanal anastomosis (HCAA) are used in anus-preserving surgery for low-lying rectal cancer. Either method can be used if the lower edge of the tumor is 4-6 cm from the anal verge. The goal of this study was to evaluate differences in the anal function after MCAA or HCAA.
  
  
  METHODS
  The subjects were 305 consecutive patients with primary rectal cancer tumors situated 4-6 cm from the anal verge who underwent curative anus-preserving surgery between 2004 and 2013. Functional assessment was performed using a questionnaire at 3, 6, 12, and 24 months after stoma closure.
  
  
  RESULTS
  Of the 305 patients, 145 underwent MCAA and 160 underwent HCAA. The median distance of the tumor from the anal verge was 6.0 cm (range 4.0-6.0) in the MCAA group and 4.5 cm (range 4.0-6.0) in the HCAA group (p < 0.001). A total of 192 patients (73%) responded to the 1-year questionnaire. The median Wexner score was 6 (range 0-17) in the MCAA group and 11 (range 0-20) in the HCAA group (p < 0.001).
  
  
  CONCLUSIONS
  Retention of anal function is feasible after both MCAA and HCAA. MCAA may contribute to better postoperative anal function compared to HCAA.
authors.affiliation: Colorectal and Pelvic Surgery Division, National Cancer Center Hospital East, Chiba, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Matsunaga
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yokota
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Hayashi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000503:physiopathology* / Q000601:surgery*; D000714:Anastomosis, Surgical / Q000379:methods; D003106:Colon / Q000601:surgery*; D003672:Defecation; D018572:Disease-Free Survival; D005242:Fecal Incontinence / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods; D012004:Rectal Neoplasms / Q000601:surgery*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D015996:Survival Rate; D013536:Suture Techniques
keywords: Anal function; Hand-sewn coloanal anastomosis; Low-lying rectal cancer; Mechanical coloanal anastomosis; Wexner incontinence score