Systematic microscopic analysis of retrieved stents from a patient with pancreatic necrosis

Pancreatic fluid collections (PFCs) are a common complication associated with pancreatic injury. Drainage of a PFC is usually indicated if a patient becomes symptomatic with complications such as bacterial superinfection, septicaemia, fistulas, biliary obstruction or gastric outlet obstruction. Endoscopic ultrasound guided drainage is a well-established minimally invasive procedure to insert stents into a fluid collection, most prominently plastic double pigtail stents (DPSs) and lumen-apposing metal stents (LAMS). Both, DPSs and LAMSs have advantages and disadvantages that need to be considered before treatment. However, the main factors leading to failure of currently available stent systems are the relatively short patency period and bacterial superinfection. In this study, we subjected two broadly used pancreatic stents, a DPS and a LAMS Hot AXIOS stent, which were retrieved from the same patient, to a systematic morphological analysis by scanning electron microscopy in order to identify factors related to stent topography and geometry and potentially involved in stent failure. Results of this work will provide essential information for future innovations regarding the stent design for drainage of PFCs