Pancreatoscopy directed laser lithotripsy in the management of obstructing intraductal pancreatic calculi. A 56-year-old gentleman with a long history of abdominal pain related to chronic pancreatitis was transferred to our centre from another hospital. His background included endocrine pancreatic insufficiency and a prior cholecystectomy. He came to us with an escalating rate of hospital admission having been admitted 12 times in the preceding 12 months. He had a complex analgesia regimen of both opioid and non-opioid analgesics. Here a 15 millimetre radiolucent stone obstructs the pancreatic duct at the head of the pancreas. After treatment the obstruction is resolved with an accompanying improvement in symptoms. Pancreatoscopy directed stone clearance may be challenging. The aim of this presentation is to demonstrate our approach to this technique. This is a video of the lithotripsy component of the procedure but it can only occur after safely achieving pancreatic duct access and insertion of the pancreatoscope. Although conventional ERCP techniques may be successful for removal, stones larger than five millimetres have often required pancreatic surgery or extracorporeal shockwave lithotripsy for treatment. More recently endoscopic approaches have evolved incorporating ERCP directed digital single operator pancreatoscopy using a digital cholangioscope combined with either electrohydraulic or holmium laser lithotripsy. Following successful lithotripsy this man who had been so debilitated by pain has not required further hospitalisation for pancreatitis though he does remain on long-term opioids via a chronic pain service. To date the data supporting pancreatoscopic lithotripsy are observational but do support its role as a safe and effective technique when compared to extracorporeal shockwave lithotripsy. Also holmium laser lithotripsy has been compared to electrohydraulic lithotripsy in a meta-analysis of series. Bick and colleagues compared outcomes between extracorporeal and pancreatoscopic lithotripsy in a single centre retrospective study. There was no difference in technical success nor post-procedural symptoms however pancreatoscopy directed electrohydraulic lithotripsy required fewer procedures and had shorter total procedure times. Gergs and colleagues collected the largest prospective cohort published to date with 40 patients with large obstructive pancreatic calculi. They showed superior complete stone clearance compared to historical performance of extracorporeal therapy as well as an impressive symptomatic response in 82% of patients with three-quarters of those having resolution of their pain. Sagir and colleagues undertook a meta-analysis of series to compare electrohydraulic and laser lithotripsy. They found laser lithotripsy to have a higher technical and clinical success rate with no difference between adverse events. This is another case of a patient who may benefit from lithotripsy. MRCP demonstrated marked pancreatic duct dilatation and an endoscopic ultrasound showed a 10 millimetre hyperechoic stone in the head of the pancreas with typical posterior acoustic shadowing. Here a radiolucent head of pancreas stone with upstream pancreatic duct dilatation is seen. Advancing a wire past occlusive stones and associated strictures is often challenging. We initially use a stiff shaft hydrophilic tipped 0.025 inch wire to negotiate past the stone and stricture. If unsuccessful alternative wires may be used including either angled tip or thinner 0.018 inch wires. Following deep placement of the wire into the pancreatic duct a pancreatic sphincterotomy is performed. A subsequent 6mm sphincteroplasty is also shown dilating the ampulla and an associated proximal pancreatic duct stricture. This facilitates subsequent pancreatoscopic passage. In this case stones blocking both the main pancreatic duct and a major side branch are progressively fragmented. Laser lithotripsy's mechanism is of plasma bubble generation. This bubble oscillates resulting in waves which fracture the stone's surface. A variety of instruments may be used to help bypass difficult stones. Here a radio-opaque stone is seen in the head of the pancreas. Passing a wire beyond the stone was difficult due to an associated stricture. A rigid, small calibre, 5 French diagnostic catheter is used to help advance the wire beyond the stone and subsequently dilate the tract. With deep wire placement, dilatation balloons, often 4mm or in this case 6mm, are advanced and used to treat the stricture. In some particularly challenging cases, a 7 French wire guided screw tipped stent removal device may be used to manoeuvre beyond the stone. A stricture in the neck and body of unclear etiology is seen here with a distal stone. The stricture was dilated to 6mm. Wire guided pancreatoscopy shows the stricture. The wire is then removed and the laser fibre inserted. Successfully advancing the fibre out of the distal end of the pancreatoscope's instrument channel may be difficult. Troubleshooting this issue includes using lubrication, straightening the duodenoscope as much as possible and releasing the duodenoscope's locks. Laser probes are 270 microns in diameter, smaller than usual electrohydraulic probes. The fibre should be manoeuvred on face with the stone to optimise fragmentation. Irrigation is usually set at 90 mls per minute. Once a stone has been fragmented and removed, the stricture can be optically examined and if there is suspicion of malignancy, targeted biopsy is acquired. Following successful lithotripsy, a balloon or basket sweep is performed to remove fragments from the duct. Usually two to three procedures are needed to achieve complete stone clearance. This may be because of multiple stones, large stones or tight strictures. Interval placement of a large calibre plastic pancreatic stent improves strictures and aids in stone fragmentation. In conclusion, symptomatic obstructing pancreatic duct stones can usually be cleared with pancreatoscopy guided laser lithotripsy. This technique should be undertaken in expert centres because of the high degree of skill required and the potential for adverse events.

pancreatoscopy

laser lithotripsy

intraductal pancreatic calculi

chronic pancreatitis

digital cholangioscope