title: Altered microperfusion at the rectal stump is predictive for rectal anastomotic leak.
abstract: OBJECTIVE
  The aim of this study was to evaluate the reliability of intraoperative laser-Doppler measurements in predicting the occurrence of anastomotic leak in patients with colorectal cancer undergoing stapled straight anastomosis to the rectum.
  
  
  METHODS
  A prospective study was undertaken on 55 patients with rectal cancer or distal sigmoid cancer programmed for elective curative surgery. In all patients transmural colonic blood flow was measured by laser-Doppler flowmetry technique before bowel manipulation (baseline measurement) and after vascular ligation and division. Comorbidities at admission, intraoperative events, associated surgical procedures, and clinical outcome were tested for any association with anastomotic leak.
  
  
  RESULTS
  Postoperative mortality was 1.8 percent (1/55 patients), and the overall morbidity was 21.3 percent. Anastomotic leak occurred in eight patients (14.5 percent). After colonic division a blood flow reduction at the rectal stump was observed in 42 patients (76.3 percent) as compared with baseline measurement. The mean rectal stump flow reduction was 6.2 percent in patients without anastomotic leak, whereas in patients who developed anastomosis breakdown it was 16 percent (P < 0.001). Mean proximal stump flow reduction was 5.1 percent in the uncomplicated patients, whereas in patients who had an anastomosis breakdown it was 12.9 percent (P < 0.01). A positive linear correlation was found between decrease in blood flow and rate of anastomotic leak.
  
  
  CONCLUSIONS
  Blood flow reduction at the rectal stump is associated with an increased risk of anastomotic leak.
authors.affiliation: Department of Surgery, Scientific Institute San Raffaele Hospital, Milan, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Vignali
authors.forename: L
authors.initials: L
authors.lastname: Gianotti
authors.forename: M
authors.initials: M
authors.lastname: Braga
authors.forename: G
authors.initials: G
authors.lastname: Radaelli
authors.forename: L
authors.initials: L
authors.lastname: Malvezzi
authors.forename: V
authors.initials: V
authors.lastname: Di Carlo
mesh_terms: D000704:Analysis of Variance; D000714:Anastomosis, Surgical / Q000009:adverse effects*; D003106:Colon / Q000098:blood supply; D004194:Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D017078:Laser-Doppler Flowmetry; D008026:Ligation; D016014:Linear Models; D008297:Male; D008833:Microcirculation / Q000503:physiopathology; D008875:Middle Aged; D010538:Peritonitis / Q000209:etiology; D011446:Prospective Studies; D012372:ROC Curve; D012003:Rectal Fistula / Q000209:etiology; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000098:blood supply* / Q000601:surgery; D012039:Regional Blood Flow / Q000502:physiology; D012307:Risk Factors; D012811:Sigmoid Neoplasms / Q000601:surgery*; D018709:Statistics, Nonparametric; D017792:Surgical Stapling / Q000009:adverse effects; D015996:Survival Rate; D016896:Treatment Outcome