The Birmingham experience of high-pressure methylene blue dye test during primary and revisional bariatric surgery: A retrospective cohort study

INTRODUCTION: Leak following bariatric surgery continues to be associated with morbidity and rarely mortality. With improvement in surgical techniques and stapler design, leak rates have reduced drastically. Intra-operative high pressure Methylene blue leak test (HPMB) is one of the techniques employed to confirm integrity of anastomoses and staple lines. Despite this, evidence for its use remains limited. We evaluated the role of HPMB in detecting and preventing leaks. METHODS: A retrospective cohort of consecutive patients who underwent primary or revisional Laparoscopic Sleeve Gastrectomy (SG) or Laparoscopic Roux-en-Y Gastric bypass (RYGB) under the care of five surgeons in three centres across Birmingham, UK, between 2012 and 2016 were assessed. All patients had routine HPMB at the end of the procedure. Demographics, HPMB positivity, and post operative leaks were recorded. RESULTS: 924 patients underwent bariatric surgery: 696(75.3%) RYGB, and 225(24.3%) SG. 85(9.2%) were revisional procedures. Two HPMB were positive, which necessitated staple or suture line reinforcement with sutures intra-operatively. The patients had an uneventful recovery. 5 patients had postoperative leaks, all of whom had negative intraoperative HPMB: 3 SG patients; and 2 RYGB patients (gastro-jejunostomy anastomotic leaks). There was no statistically significant relationship between positive HPMB and anastomotic leak (Fishers exact test; p = 1). CONCLUSION: Despite routine use of methylene blue dye test in 924 patients, there were only two positive tests. Whilst HPMB may demonstrate technical failure, this study suggests that there is no role for its routine use in primary bariatric surgery. Discontinuation of this practice would reduce risk of anaphylaxis to the dye, cost, and intra-operative time.