Asymptomatic cholelithiasis is a prevalent condition in obese patients presenting for bariatric surgery. Transabdominal ultrasound (TAU) remains the gold standard for detection of cholelithiasis. The sensitivity and specificity of transabdominal ultrasound for cholelithiasis reported in literature is between 88-97% and 97-99%, respectively. The ability to detect cholelithiasis with TAU in the obese population may be inhibited due to the presence of increased subcutaneous and visceral fat. Laparoscopic ultrasound (LU) has the potential to overcome these technical challenges. In an era of minimally invasive bariatric surgery, it has been suggested that routine preoperative ultrasound TAU be performed for the detection of cholelithiasis since intraoperative palpation is not feasible. We hypothesize that laparoscopic ultrasound will be more sensitive and specific for cholelithiasis than transabdominal ultrasound in morbidly obese patients.
The objective of this study is to prospectively compare laparoscopic ultrasound to transabdominal ultrasound for the detection of gallbladder pathology in obese patients presenting for laparoscopic gastric bypass. We hypothesize that laparoscopic ultrasound will be more sensitive and specific for cholelithiasis than transabdominal ultrasound in morbidly obese patients.