Technical review of endoscopic ultrasound-guided drainage/anastomosis and trans-endosonographically created route procedures for the treatment of pancreatic diseases.

Endoscopic ultrasound (EUS)-guided pancreatic duct drainage includes two procedures: EUS-guided drainage/anastomosis (EUS-D/A) and trans-papillary drainage with EUS-assisted pancreatic rendezvous. EUS-guided pancreatogastrostomy is the most common EUS-D/A procedure and is recommended as a salvage procedure in cases in which endoscopic retrograde cholangiopancreatography fails or is difficult. However, initial EUS-D/A is performed in patients with surgically altered anatomy at our institution. It is one of the most difficult interventional EUS procedures and has a high incidence of adverse events. The technical difficulties differ according to etiology, and the incidence of adverse events varies between initial EUS-D/A and subsequent trans-endosonographically/EUS-guided created route procedures. Hence, it is important to meticulously prepare a procedure based on the patient's condition and the available devices. The technical difficulties in EUS-D/A include: (1) determination of the puncture point, (2) selection of a puncture needle and guidewire, (3) guidewire manipulation, and (4) dilation of the puncture route and stenting. Proper technical procedures are important to increase the success rate and reduce the incidence and severity of adverse events. The complexity of EUS-D/A is also contingent on the severity of pancreatic fibrosis and stricture. In post-pancreatectomy cases, determination of the puncture site is important for success because of the remnant pancreas. Trans-endosonographically/EUS-guided created route procedures following initial EUS-D/A are also important for achieving the treatment goal. This article focuses on effective strategies for initial EUS-D/A, based on the etiology and condition of the pancreas. We mainly discuss EUS-D/A, including its indications, techniques, and success-enhancing strategies.