Utility of Peroral Cholangioscope (Spy Glass System) in Treatment of Stones in Chronic Pancreatitis

Abstract

Chronic pancreatitis is a difficult clinical condition to treat. Stones in the main pancreatic duct could lead to increased ductal pressure and cause pain, inflammation and other complications. Endoscopic therapy is aimed at reduction of the pressure in the main pancreatic duct. Endoscopic armamentarium is limited. Extracorporeal shock wave lithotripsy though useful is available only at a very few centers in the United States. Mechanical lithotripsy is difficult and is associated with significant complications including the inability to crush the stones, broken and captured baskets. Electro hydraulic lithotripsy (EHL) would be beneficial but could not be used earlier because of the limitation of direct visualization of the stones in the main pancreatic duct. Recently a single operator duodenoscope assisted cholagiopancreatoscopy (Spy glass system, Boston Scientific, MA) was introduced. This was primarily developed for evaluation and treatment of biliary tract disease. Aim: To evaluate the feasibility and efficacy of electrohydraulic lithotripsy of main pancreatic duct stones in chronic pancreatitis using Spy glass system. Methods: Retrospective analysis of the data of pancreatoscopies done using Spy glass. Results: Between July 07 and November 07, 16 procedures were performed with Spy glass system. 8 patients had chronic pancreatitis. Of these 8, 2 underwent cholangioscopy for evaluation of the bile duct and 6 underwent pancreatoscopy. Main pancreatic duct calcifications were seen in 5 patients and EHL was performed. In 4 of the 5 patients stones could be fragmented by EHL and subsequently stones were removed by stone/basket. All the stones could not be removed and 2 of these patients had subsequent pancreatoscopies with removal of more stone material. In one case EHL was attempted but was unsuccessful because of difficult angulation and inability to achieve adequate contact between the probe and the stone. No procedure related complications were seen. Conclusions: 1. Spy glass system allows for direct visualization of the stones in the main pancreatic duct and EHL could be safely performed to decompress the main pancreatic duct. This adds to the current armamentarium of the endoscopic accessories for therapy of pancreatic stones. 2. Limitations include use in non dilated/strictured ducts because of the current size of the catheter (7Fr) and maneuverability within the duct. 3. Currently used EHL probes are designed for urological procedures and hence the length of the probe is a limitation, moreover the probe is not rigid and can kink easily. Specially designed probes are in development and might solve this problem.