Laparoscopic ultrasonography as an alternative to intraoperative cholangiography during laparoscopic cholecystectomy

AIM To assess the role of laparoscopic ultrasound (LUS) as a substitute for intraoperative cholangiography (IOC) during cholecystectomy. METHODS We present a MEDLINE and PubMed literature search, having used the key-words "laparoscopic intraoperative ultrasound" and "laparoscopic cholecystectomy". All relevant English language publications from 2000 to 2016 were identified, with data extracted for the role of LUS in the anatomical delineation of the biliary tract, detection of common bile duct stones (CBDS), prevention or early detection of biliary duct injury (BDI), and incidental findings during laparoscopic cholecystectomy. Data for the role of LUS vs IOC in complex situations (i.e., inflammatory disease/fibrosis) were specifically analyzed. RESULTS We report data from eighteen reports, 13 prospective non-randomized trials, 5 retrospective trials, and two meta-analyses assessing diagnostic accuracy, with one analysis also assessing costs, duration of the examination, and anatomical mapping. Overall, LUS was shown to provide highly sensitive mapping of the extra-pancreatic biliary anatomy in 92%-100% of patients, with more difficulty encountered in delineation of the intra-pancreatic segment of the biliary tract (73.8%-98%). Identification of vascular and biliary variations has been documented in two studies. Although inflammatory disease hampered accuracy, LUS was still advantageous vs IOC in patients with obscured anatomy. LUS can be performed before any dissection and repeated at will to guide the surgeon especially when hilar mapping is difficult due to fibrosis and inflammation. In two studies LUS prevented conversion in 91% of patients with difficult scenarios. Considering CBDS detection, LUS sensitivity and specificity were 76%-100% and 96.2%-100%, respectively. LUS allowed the diagnosis/treatment of incidental findings of adjacent organs. No valuable data for BDI prevention or detection could be retrieved, even if no BDI was documented in the reports analyzed. Literature analysis proved LUS as a safe, quick, non-irradiating, cost-effective technique, which is comparatively well known although largely under-utilized, probably due to the perception of a difficult learning curve. CONCLUSION We highlight the advantages and limitations of laparoscopic ultrasound during cholecystectomy, and underline its value in difficult scenarios when the anatomy is obscured.