Waterjet necrostectomy device (WAND) for endoscopic management of pancreatic necrosis: design, development, and preclinical testing (with videos).

Abstract Background and Aims Endoscopic intervention has emerged as a first-line option for management of symptomatic pancreatic necrosis, yet endoscopic debridement is limited by the lack of dedicated endoscopic tools intended for this purpose. The objectives of this study were to design and build a prototype necrosectomy device compatible for use with a flexible endoscope and capable of selective tissue fragmentation, and to test the prototype in benchtop and porcine models. Methods A novel prototype, named the WAterjet Necrosectomy Device (WAND), was designed and developed, consisting of a single-use disposable endoscopic waterjet instrument capable of waterjet selection and independent tip articulation while fitting through a 2.8 mm working channel of a standard adult upper gastrointestinal endoscope. Benchtop, ex vivo, and in vivo (porcine) testing was performed in the initial stages of investigation. Results The WAND was constructed capable of delivering a continuous waterjet force with a surface pressure of 0.72 bar at a flow rate of 0.37 L/minute. In phase I of testing, the WAND was able to achieve complete fragmentation of gelatin as a surrogate for pancreatic necrosis in benchtop testing. In phase II of testing, the WAND was able to achieve complete fragmentation of freshly explanted human pancreatic necrosis. In phase III of testing for safety in fresh necropsy swine, use of the WAND resulted in no significant tissue trauma, even when irrigation was applied at closer proximity and at more extended duration than would be anticipated in clinical use. Conclusion The WAND prototype delivers irrigation capable of fragmenting necrotic debris ex vivo and also avoiding trauma to healthy nontarget tissue. Planning is underway for first-in-human studies to assess the efficacy and safety of the WAND for endoscopic pancreatic necrosectomy.