Early Experience with Intraoperative Leak Test Using a Blend of Methylene Blue and Indocyanine Green During Robotic Gastric Bypass Surgery

Obes Surg. 2019 Mar;29(3):949-952. doi: 10.1007/s11695-018-03625-2.


Introduction: Leak tests using air or methylene blue (MB) for gastrojejunal anastomoses are often performed during gastric bypass surgeries to avoid leaks due to technical errors. Still, early leaks have been reported in the literature. Indocyanine green (ICG) fluorescence with laser excitement makes this dye easily visible even in small amounts, and, thus, may be an excellent agent for leak testing.

Methods: During robotic gastric bypass surgery, a leak test of a gastrojejunal anastomosis was performed with air through a nasogastric tube under manual occlusion of the jejunum. Afterward, 50 ml of a mix of 100 ml sterile water, 2 mg of MB, and 5 mg ICG was injected through the same tube. The entire anastomosis was inspected for integrity under both fluorescent and normal light modes.

Results: Leak tests with air and the blend of MB and ICG have been performed in 95 patients from January 2017 to April 2018. No intraoperative leak test-related adverse events occurred. Zero (0%) patients had a positive leak test with air, 0 patients showed MB excretion, and an ICG leak was observed in four (4.2%) patients. No anastomotic complications, including leaks and/or strictures, were found 30 days postoperatively.

Conclusions: Leak tests using a blend of MB and ICG appear to be more sensitive for small defect detection of gastrojejunal anastomoses during robotic gastric bypass surgery. Larger datasets and research that is more stringent are needed to determine the exact clinical value of this new method.

Keywords: Anastomotic test; Gastric bypass; Indocyanine green; Leak test; Methylene blue.

MeSH terms

  • Adult
  • Air
  • Anastomosis, Surgical / adverse effects
  • Anastomosis, Surgical / methods
  • Anastomotic Leak / diagnosis*
  • Anastomotic Leak / etiology
  • Coloring Agents / administration & dosage*
  • Female
  • Fluorescence
  • Gastric Bypass / adverse effects*
  • Gastric Bypass / methods
  • Humans
  • Indocyanine Green / administration & dosage*
  • Jejunum / surgery
  • Male
  • Methylene Blue / administration & dosage*
  • Middle Aged
  • Obesity, Morbid / surgery*
  • Robotic Surgical Procedures / adverse effects
  • Robotic Surgical Procedures / methods
  • Solutions / administration & dosage
  • Stomach / surgery


  • Coloring Agents
  • Solutions
  • Indocyanine Green
  • Methylene Blue