Shape memory alloy catheter system for peroral pancreatoscopy using an ultrathin-caliber endoscope

Two types of a shape memory alloy (SMA) catheter system with a mechanism for tip control and irrigation were evaluated in performing peroral pancreatoscopy (PPS) using an ultrathin-caliber endoscope. The selective cannulation of SMA catheters into the papilla was made possible in 18 of 19 patients with pancreatic diseases. Endoscopic sphincterotomy was necessary in six of seven patients with the two-directional catheter (2.6 mm) but in only one of 12 patients examined with the one-directional type (2.2 mm). In 17 of the 18 patients, the catheters were smoothly advanced to the desired positions in the main pancreatic duct, even to the distal pancreas, due to their controllable tip. PPS with adequate inspection of the ducts and lesions was successful in 16 of these 17 patients. Features of cancer (duct disruption, tumor infiltration) and chronic pancreatitis (smooth ductal surface, fine vascular network) could be distinguished. In this series, there were no obvious complications during or after the procedure. In our experience, the SMA catheter system is effective for PPS in patients with an intact papilla and without dilation of the main pancreatic duct. Further study will show the clinical benefits this technique may have in pancreatic diseases.