Rolling Stone's laser show. These are our disclosures. Colonic gallstone ileus is a rare complication of cholelithiasis. The sigmoid colon is the most common segment of impaction. Management has primarily been surgical, but endoscopic maneuvers have been applied in certain scenarios with overall lower success rates. Endoscopic guided laser lithotripsy has sometimes been applied in ERCP with cholangioscopy, but rarely has been reported as a modality for impacted colonic gallstones. A 62 year old female presents with a four-day history of diffuse abdominal pain with nausea and vomiting. Previous history was notable for a gallbladder mass where the biopsy revealed acute on chronic inflammation. CT of the abdomen and pelvis five months prior to presentation was notable for a gallbladder mass as indicated by the yellow arrows below. Although there were initial concerns for malignancy, biopsy results were reassuring, raising suspicion for a gallstone. CT scan on current presentation was concerning for a hypoattenuating mass at the sigmoid colon, raising suspicions that the previously noted gallstone in the gallbladder had migrated to the sigmoid colon as shown by the yellow arrows. Upstream colonic dilation was also noted on the coronal image with the yellow arrowhead. A cholecystocolonic fistula was also noted. Lower endoscopy revealed an impacted gallstone at the sigmoid colon. Our first session consisted of a flexible sigmoidoscopy under general anesthesia where conventional methods including flexible snares, biliary and esophageal balloon dilator sweeps, and tripod graspers were trialed. A large braided snare was unsuccessful for stone retrieval given the smooth nature of the stone which caused the snare to slip off the stone. Using a wire, we placed a biliary balloon behind the stone. However, sweeping was unsuccessful given the impacted nature of the stone. An esophageal balloon dilator was also placed behind the stone with the assistance of a guide wire. Sweeping the stone again was unsuccessful given the impaction of the stone and the angulation of the sigmoid. Tripod graspers could not securely hold the stone given the slick surface of the stone. A second attempt at endoscopy was planned with the use of endoscopic guided laser lithotripsy to help break up the stone to aid in removal. Endoscopic guided laser lithotripsy was initially implemented to help break up the stone. However, given the large nature of the stone, we opted for a more targeted approach. A second attempt at endoscopy was refined with the use of endoscopic guided laser lithotripsy to create a traversable hole within the core of the gallstone to pass a guide wire driven balloon dilator through the core, thereby breaking the stone from within. The pieces would be retrieved with a snare or basket retriever. Laser lithotripsy was used with the laser set to 30 joules of 5 hertz by 15 watts. We used underwater technique for the laser to aid in visualization by preventing stone debris from obscuring view. We focused on creating a traversable hole within the core of the stone to aid in balloon dilation. CO2 was used at lowest setting possible to avoid upstream or proximal colon perforation. Throughout the procedure, the patient's abdomen was repeatedly examined to assess for distention. A guide wire was used to pass an esophageal balloon dilator through the core of the stone under fluoroscopic guidance to ensure safe and accurate dilation of the core of the stone. Fluoroscopic imaging was used to ensure proper placement of the guide wire driven balloon dilator through the core of the stone. The balloon dilator was inflated up to 20 millimeters in the center of the stone to help break the stone into several pieces. Fluoroscopic imaging confirmed successful breakage of the stone with uniform dilation of the balloon. Fragments of the stone are retrieved with the retrieval basket and cold snare until all contents of the stone are removed from the colon. All fragments of the stone were successfully removed. Subsequent endoscopic examination of the impacted area following stone removal revealed healthy mucosa and no obvious deep mucosal damage. Our case demonstrates that surgery may be avoided in patients who present with colonic gallstone ileus. Endoscopic guided laser lithotripsy may be applied when conservative endoscopic approaches fail or in patients who are poor surgical candidates. Endoscopic guided laser lithotripsy of obstructive colonic gallstones may be feasible in the appropriate clinical setting. Further studies are needed to replicate our technique and assess the overall safety and efficacy of our approach.

colonic gallstone ileus

endoscopic guided laser lithotripsy

cholelithiasis

guide wire-driven balloon dilator

fluoroscopic imaging