Novel Technique Using EUS Guided Submucosal Injection to Aid Minor Papilla Identification in a Patient With Pancreas Divisum and Pancreaticolithiasis

Abstract

Introduction: Pancreas divisum can make pancreaticobiliary endoscopy a challenge. Minor papilla identification and cannulation can be difficult and lead to procedural failures. We present a novel technique of endoscopic ultrasound (EUS) guided submucosal injection to aid localization of the minor papilla in a patient with pancreas divisum, chronic pancreatitis, and a large pancreatic duct stone. Case: A 69 year old Caucasian male with recurrent acute pancreatitis was referred for EUS to evaluate pancreatic duct dilation and pancreas divisum noted on magnetic resonance cholangiopancreatography. EUS was consistent with chronic pancreatitis based on the Rosemont criteria, with pertinent findings to include a dilated pancreatic duct (5 mm) and a large calcified stone in the pancreatic head. Given his history of recurrent pancreatitis, endoscopic retrograde cholangiopancreatography (ERCP) was performed with the goal of papillotomy and stone extraction. ERCP confirmed pancreas divisum, however minor papilla identification was unsuccessful despite gentle exploration of duodenal folds and application of methylene blue. After discussion with the patient, he returned for a combined EUS/ERCP procedure. A linear echoendoscope was used to identify the main pancreatic duct stone, which was in the distal duct of Santorini. A submucosal injection with methylene blue was then performed via a 25 gauge FNA needle at the level of the stone. Upon re-inspection with the duodenoscope, the minor papilla was identified immediately adjacent to the injection site. The minor papilla was cannulated and pancreatogram confirmed pancreas divisum and a proximal filling defect. A 5 Fr x 5 cm dual flanged plastic pancreatic stent was placed for extracorporeal shock wave lithotripsy (ESWL) targeting. He returned after ESWL for ERCP with stent removal. Pancreatogram confirmed no large filling defect within the pancreatic duct. Balloon sweeps with a 9 mm extraction balloon yielded stone fragments. He has had no further episodes of acute pancreatitis. Discussion: Minor papilla identification and cannulation can be challenging. When the minor papilla cannot be readily identified, there are limited described techniques to help identify the minor papilla (spraying methylene blue, secretin administration). Here we describe a case using EUS guided submucosal injection to identify the minor papilla in a patient with pancreas divisum demonstrating that EUS can be used to locate the minor papilla.1277_A.tif Figure 1: Calcified pancreatic duct stone in the dorsal pancreatic duct.1277_B.tif Figure 2: Minor papilla identified just distal to the site of submucosal methylene blue injection.1277_C.tif Figure 3: Following cannulation, a dual flanged 5 Fr x 5 cm plastic pancreatic duct stent was placed through the minor papilla adjacent to the submucosal methylene blue injection.