“D-SOC with either [electrohydraulic lithotripsy or laser lithotripsy] represents an efficient, highly valuable, safe and minimally invasive alternative to percutaneous or surgical approaches in the management of difficult biliary stones,” reported Olaya I. Brewer Gutierrez, MD, of Johns Hopkins Hospital, Baltimore, and her colleagues.
The study, published in Clinical Gastroenterology and Hepatology, involved 22 tertiary centers in the United States, the United Kingdom, and Korea. Patients had difficult biliary stones, defined as stones greater than 15 mm in size, multiple (more than three) stones, intrahepatic duct/cystic duct stones, impacted stones, and stones associated with Mirizzi syndrome or a difficult biliary anatomy such as stricture below the stone or duodenal diverticula.
Most patients (85.7%) had a prior failed treatment with endoscopic retrograde cholangiopancreatography (ERCP) for stone clearance at outside hospitals, with biliary sphincterotomy and the use of an extraction balloon attempted in 62.2% and 73.2% of these cases, respectively.
Of the 407 study patients, 306 (75.2%) were treated with electrohydraulic lithotripsy (EHL), and 101 (24.8%) were treated with laser lithotripsy (LL). Complete ductal clearance was achieved in 396 (97.3%) of patients with a median of one lithotripsy session (range of one to four sessions), and in 77.4% of patients in a single session. Stone clearance rates and procedure outcomes were similar between the two approaches, but the mean procedure time was significantly longer with EHL than with LL (74 vs. 50 minutes).
Eleven (2.7%) of the 407 patients failed EHL/LL and were treated either with surgery, extracorporeal shock-wave lithotripsy, or both. Adverse events were observed in 15 patients (3.7%), with cholangitis and abdominal pain most commonly reported.
In addition to evaluating the technical success of D-SOC for difficult bile duct stones and comparing the effectiveness of EHL and LL, the investigators looked for predictors of outcomes. On multivariate analysis, they found difficult anatomy/cannulation was associated with incomplete ductal clearance, and the duration of the procedure was a predictor of the need for more than one D-SOC.
The introduction of D-SOC several years ago has “improved the ease of SOC and markedly improved the image quality,” Dr. Gutierrez and her colleagues wrote. “These [improvements] have led to greater use of EHL or LL as part of the ERCP armamentarium to attempt stone clearance in difficult biliary or pancreatic stones.”
Still, given the retrospective nature of the study and subsequent selection bias, randomized controlled trials comparing D-SOC and EHL/LL with conventional techniques for stone extraction are needed, they say.
In an accompanying editorial, Dennis Yang, MD, of the University of Florida, and Jonathan M. Buscaglia, MD, AGAF, of State University of New York at Stony Brook commended the study for critically evaluating a new technology, but said that “it still remains unclear in whom D-SOC with EHL or LL should be considered over conventional ERCP with stone extraction techniques.”
Although most patients in the study had a prior failed ERCP, conventional stone extraction techniques such as endoscopic sphincterotomy with endoscopic papillary large balloon dilation (EPLBD) or mechanical lithotripsy were attempted in less than a quarter of the cases before D-SOC, they wrote. “In the era of high-cost health care, it is important that proven and effective measures for the treatment of stones ... be used adequately before moving up the ladder to cholangioscopy-based techniques.”
Eleven of the study authors reported serving as consultants for Boston Scientific, which manufactures the D-SOC system used at the study sites, and two of the investigators reported serving as speakers for the company. Dr. Gutierrez reported no conflicts of interest.
SOURCE: Brewer Gutierrez OI et al. Clin Gastroenterol Hepatol. 2018;16:918-26.
