Resection of an anal fistula with endoscopic submucosal dissection.

A 34-year-old man presented with paroxysmal hypogastralgia during defecation for 2 weeks. Physical and laboratory examination findings were unremarkable, other than a depression located 1 cm above the dentate line, accompanied by mild tenderness and a clubbed induration extending to the rectum. Colonoscopy showed a 2.0×0.8 cm longitudinal, protruding mass in the posterior wall of the lower rectum. Endosonography revealed a mixed echogenic mass originating from the rectal submucosa, with no sign of muscular wall disruption. There was no evidence of Crohn's or other diseases. Following anorectal consultation, we suspected a submucosal or internal blind fistula since the patient was symptomatic with a superficial mass which communicated to the rectum. The location and depth of the mass indicated that endoscopic resection might allow for removal of the lesion without impairment of the anorectal anatomy and function. After obtaining the patient's consent, endoscopic submucosal dissection (ESD) was performed. En bloc resection was achieved using a disposable, high-frequency knife (Micro-Tech, China). No adverse events occurred. Histopathological examination revealed a benign fistula composed of local submucous granulomatous tissue proliferation and a focal mucous epithelial defect. The patient's symptoms were relieved postoperatively, and no recurrence was evident after 6 months.

Systemic injury caused by taurocholate-induced severe acute pancreatitis in rats.

Systemic injury plays a central role in severe acute pancreatitis (SAP). Retrograde biliopancreatic duct infusion of sodium taurocholate (NaT) is commonly used to establish SAP animal models. To better characterize the systemic injury in this model, SAP was induced in Sprague-Dawley rats by NaT administration (3.5 or 5%), followed by sacrifice at 3, 6, 9, 12, 24, 48 and 72 h. Normal saline was used as a control in Sham-operated rats. The mortality rate, ascites volume, and serum and ascitic fluid amylase and lipase activities were assessed. Multiple organ dysfunction, including dysfunction of the pancreas, lung, ileum, liver, and kidney, was investigated using hematoxylin and eosin staining. The interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α levels in the ascitic fluid, serum, and ileum tissues were evaluated using an enzyme-linked immunosorbent assay (ELISA). Tight junction proteins, zonula occludens-1 (ZO-1) and occludin, in ileum tissues were studied using immunofluorescence. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE) and urea levels were measured using an automatic biochemical analyzer. The results of the present study indicated that both 3.5 and 5% NaT could induce a stable elevation of pancreatitis indices, with histopathological injury of the pancreas, lungs and ileum (5% NaT). The ascitic fluid levels of IL-6 and IL-1ß were increased in the 5% NaT group. ALT and AST levels increased temporarily and recovered in 72 h, without a significant increase in CRE and urea levels or apparent hepatic and renal pathological injury. In conclusion, rats with NaT-induced SAP have characteristics of necrotizing hemorrhagic pancreatitis with multiple organ injuries, including inflammatory lung injury, ischemic intestinal injury and slight liver and kidney injuries.