Endoscopic laser lithotripsy as management of gallstone ileus in a non-surgical candidate. Primary author, Richard M. Fazio. Co-authors, Hari Sayana, Sandy Patel, Shreyas Salagram, and Laura Rosenkranz. These are our disclosures. A 77-year-old female presented with one week of progressively worsening abdominal pain associated with decreased appetite, bilious vomiting, and obstipation. Past medical history was significant for cryptogenic cirrhosis complicated by hepatic encephalopathy, ascites, hepatic hydrothorax, and non-bleeding esophageal varices, with a known history of cholelithiasis. On physical examination, she was afebrile and hemodynamically stable, with abdominal distension, diffused tenderness to palpation, tympani heard during percussion, and decreased bowel sounds and auscultation. The patient's white blood cell count was 3.26,000, platelet count of 52,000, BUN 29, carotene of 1.05, sodium of 132, and INR 1.3. Metal sodium was 11. A CT scan of the abdomen and pelvis with IV contrast showed a markedly dilated stomach and small bowel, with a 4 cm partially calcified gallstone in the proximal jejunum, as well as a cholecystoduodenal fistula with collapsed gallbladder. The patient was kept NPO with placement of nasogastric tube for decompression. IV fluids were administered along with electrolyte replacement. Due to the patient's advanced age and medical comorbidities, she was deemed too high risk for surgery, and therefore attempt at endoscopic lithotripsy was initiated, ultimately performed in two 1-hour sessions over a 48-hour period. A pediatric colonoscope was advanced using water immersion technique and gentle pressure to the proximal jejunum. A large obstructing stone with overlying bilious debris was identified. Saline lavage was performed, revealing a large brown stone with surrounding superficial mucosal ulcerations and nerithema. Holmium YAG laser lithotripsy was performed using a flexible 365-micron probe passed through the working channel of the pediatric colonoscope. Continuous saline installation was applied in order to provide a medium in which to safely transfer heat energy to the impacted stone. The laser pulse energy and rate settings were adjusted throughout the case, beginning with 2 joules energy and 5 hertz frequency, equating to a power of 10 watts. The use of laser lithotripsy has recently come into favor when treating refractory coelodocal lithiasis. The concept involves the creation of a plasma bubble caused by the collection of ions and free electrons between the laser probe and the stone surface. The oscillation of the bubble and eventual collapse of this bubble creates pulse-shocked waves, thus contributing to the fragmenting effect. Since the advent of pulse laser, the risk of thermal injury to the bioduct has been significantly reduced. However, few trials have reported on the safety and efficacy of Holmium laser for treatment of refractory bioduct stones, and the same can be said for treatment of enteral stones. Our institution has recently conducted studies to determine safe yet effective energy settings for the Holmium YAG laser in the ex vivo model, with the hope of its eventual clinical use. The study was conducted on porcine bioduct epithelium and human gallstones to first identify which power settings would pose higher risk of perforation on surrounding epithelial tissue, and second, which setting would be more applicable for treatment of larger size stones. As the graph indicates, when applying a range of power from 8 watts to 15 watts, the time to perforation was lower in the group with higher power, or wattage. While the lower power did seem beneficial with regard to side effect profile, it was also deemed less effective in the treatment of larger size stones. Here we see the application of the Holmium YAG laser at differing power settings over the same period of time. The graphic clearly shows the advantage of the higher power setting in treating these larger stones. Our studies also found that larger fibers, that is, the 550 micron probe, had a higher rate of fragmentation as compared to the smaller 365 micron probe at equivalent power settings for stones larger than 2 centimeters. Unfortunately, the 550 micron probes were not available for our case and likely contributed to longer than expected procedural time. After the second hour-long endoscopic session the following day, the stone was eventually broken down completely and distal lumen clearly identified. The patient was encouraged to take in carbonated beverages following the procedure to ensure further fragmentation of stone particles and thus aid in passage through the remaining small bowel and ileocecal valve. The patient's symptoms improved immediately following the procedure and a repeat CT scan of the abdomen showed resolution of gastric and small bowel dilation. Before eventual discharge from the hospital, it was again discussed with patient and family that further surgical intervention with interval cholecystectomy and fistula closure would be too high risk given comorbidities. It should also be noted that there remains risk of recurrent gallstone ileus, cholecystitis and Q. cholangitis. However, in cases of cholecystoduodenal fistula, the probability of spontaneous closure is relatively high. Additional clinical implications of this case and our institution's research pertaining to laser lithotripsy are as follows. Homium YAG laser was found to be safe in the bile duct when used at 5-second burst at power settings between 8 watts and 12 watts. We believe these same settings should be utilized for reliable and safe fragmentation of biliary stones within the small bowel. Larger stone size and higher generator frequency decreased the ability to successfully fragment stones using smaller probe fibers. Larger fibers, 550 micron, at higher wattages set with low frequencies, that is 12 watts at 5 hertz, were found to have a greater rate of success at fragmenting large stones greater than 2 centimeters and therefore should be considered first line for treatment of luminal stones. Patients with gallstone ileus often suffer from delayed diagnosis, advanced age and multiple comorbidities all contributing to their high morbidity and mortality. For non-surgical candidates, such as the patient described in this case, endoscopic therapy should be considered for fragmentation of stones within the stomach and the proximal small bowel. With the advancement of lithotripsy techniques such as homium YAG laser and the basic understanding of generator settings as they apply to large caliber stones, endotherapy has shown to be an effective means of treatment for gallstone ileus in the high risk population.

case study

gallstone ileus

endoscopic laser lithotripsy

Holmium YAG laser

non-surgical candidates