title: Intraoperative leak testing has no correlation with leak after laparoscopic sleeve gastrectomy.
abstract: BACKGROUND
  Staple line leak is a serious complication of sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak; however, the utility of these tests is controversial. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy.
  
  
  METHODS
  A retrospective cohort study was designed using a prospectively collected database of seven bariatric surgeons from two institutions. All patients who underwent sleeve gastrectomy from March 2012 to November 2014 were included. The performance of intraoperative leak testing and the type of test (air or methylene blue) were based on surgeon preference. Data obtained included BMI, demographics, comorbidity, presence of intraoperative leak test, result of test, and type of test. The primary outcome was leak rate between the leak test (LT) and no leak test (NLT) groups. SAS version 9.4 was used for univariate and multivariate analyses.
  
  
  RESULTS
  A total of 1550 sleeve gastrectomies were included; most were laparoscopic (99.8%), except for one converted and two open cases. Routine intraoperative leak tests were performed in 1329 (85.7%) cases, while 221 (14.3%) did not have LTs. Of the 1329 cases with LTs, there were no positive intraoperative results. Fifteen (1%) patients developed leaks, with no difference in leak rate between the LT and NLT groups (1 vs. 1%, p = 0.999). After adjusting for baseline differences between the groups with a propensity analysis, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 17.3 days postoperatively (range 1-67 days). Two patients with staple line leaks underwent repeat intraoperative leak testing at leak presentation, and the tests remained negative.
  
  
  CONCLUSIONS
  Intraoperative leak testing has no correlation with leak due to laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak.
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA. monica.sethi@nyumc.org.
authors.forename: Monica
authors.initials: M
authors.lastname: Sethi
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Zagzag
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Karan
authors.initials: K
authors.lastname: Patel
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Magrath
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Somoza
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Manish S
authors.initials: MS
authors.lastname: Parikh
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Saunders
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Aku
authors.initials: A
authors.lastname: Ude-Welcome
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Schwack
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Kurian
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: George A
authors.initials: GA
authors.lastname: Fielding
authors.affiliation: Department of Surgery, New York University School of Medicine, 530 First Ave., Suite 10S, New York, NY, 10016, USA.
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Ren-Fielding
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D057868:Anastomotic Leak / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005743:Gastrectomy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D009767:Obesity, Morbid / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D017792:Surgical Stapling; D055815:Young Adult
keywords: Fistula; Intraoperative leak test; Leak; Methylene blue; Sleeve gastrectomy; Staple line