title: Evaluating the effect of operative technique on leaks after laparoscopic sleeve gastrectomy: a case-control study.
abstract: OBJECTIVE
  To assess the effect of operative technique on staple line leaks after laparoscopic sleeve gastrectomy (LSG).
  
  
  BACKGROUND
  Staple-line leaks after LSG are a major source of morbidity and mortality. Variations in operative technique exist; however, their effect on leaks is poorly understood.
  
  
  METHODS
  We analyzed data from the Michigan Bariatric Surgery Collaborative (MBSC) to perform a case-control study comparing patients who had a clinically significant leak after undergoing a primary LSG to those who did not. A total of 45 patients with leaks were identified between January 2007 and December 2013. The leak group was matched 1:2 to a control group based on procedure type, age, body mass index, sex, and year the procedure was performed. Technique-specific factors were assessed by reviewing operative notes from all primary bariatric procedures in our study population. Conditional logistic regression was used to identify techniques associated with leaks. To increase the power of our analysis, we used a significance level of .10.
  
  
  RESULTS
  Leak rates with LSG have decreased over the past 5 years (1.18% to .36%) as annual case volume has increased (846 cases/yr to 4435 cases/yr). Surgeons who performed 43 or more cases per year had a leak rate<1%. Leaks were more common among cases requiring a blood transfusion (26.2% versus 1.08%, P = .0031) and when cases were converted to open surgery (7.14% versus 0%, P = .0741). However, there was no significant difference in operative time between cases involving a leak and their matched controls (95.4 min versus 87.1 min, P = .1197). Oversewing of the staple line was the only technique associated with less leaks after controlling for confounding factors (OR .397 CI .174, .909, P = .0665). Notably, surgeons who oversewed routinely were also found to have higher case volume (307 versus 140, P = .0216) and less overall complication rates (4.81% versus 7.95%, P = .0027). Furthermore, oversewing technique varied widely as only 22.6% of cases involved oversewing of the entire staple line.
  
  
  CONCLUSIONS
  Despite considerable variation in operative technique, leak rates with laparoscopic sleeve gastrectomy have decreased over time as operative volume has increased. Oversewing of the staple line was associated with fewer leaks, but specific suturing technique was not uniform and oversewing was performed routinely by more experienced surgeons with higher case volumes and less complication rates overall. Before standardizing surgical technique one must take into account variations in surgeon skill and experience.
authors.affiliation: Department of Surgery, University of Michigan Health Systems, Ann Arbor, Michigan. Electronic address: ovarban@med.umich.edu.
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Varban
authors.affiliation: Department of Surgery, University of Michigan Health Systems, Ann Arbor, Michigan.
authors.forename: Kyle H
authors.initials: KH
authors.lastname: Sheetz
authors.affiliation: Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan.
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Cassidy
authors.affiliation: Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan.
authors.forename: Amanda
authors.initials: A
authors.lastname: Stricklen
authors.affiliation: Wayne State University, Detroit, Michigan; Department of Surgery, Henry Ford Health System, Dearborn, Michigan.
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Carlin
authors.affiliation: Department of Surgery, University of Michigan Health Systems, Ann Arbor, Michigan; Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan.
authors.forename: Justin B
authors.initials: JB
authors.lastname: Dimick
authors.affiliation: Department of Surgery, University of Michigan Health Systems, Ann Arbor, Michigan.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Finks
mesh_terms: D057868:Anastomotic Leak / Q000453:epidemiology / Q000209:etiology / Q000601:surgery*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D009767:Obesity, Morbid / Q000601:surgery*; D061646:Operative Time; D011446:Prospective Studies; D012086:Reoperation; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013997:Time Factors
keywords: Bariatric surgery; Buttressing reinforcement; Complications; Outcomes; Skill; Sleeve gastrectomy; Technique