Waterjet submucosal dissection of porcine esophagus with the HybridKnife and ERBEJET 2 system: a pilot study

Background and study aims Esophageal endoscopic submucosal dissection (ESD) is technically difficult because of narrow working spaces and ease of perforation due to the lack of serosa. HybridKnife is a recently developed ESD device that is combined with the high pressure waterjet ERBEJET 2 system to lift mucosa. We hypothesized that this waterjet could make submucosal dissection safer and studied this in porcine esophagus.Materials and methods Water pressures of 30 – 70 bar were tested to determine the appropriate pressure for waterjet ESD with HybridKnife (WJ-ESD) in one pig. WJ-ESD safety and completion were compared with those of conventional ESD using DualKnife (C-ESD) as a reference. Each of three virtual esophageal lesions in two pigs were resected alternatively using both methods from the lower to upper esophagus. For WJ-ESD, the submucosa, apart from hard fibrous tissues, was dissected using water pressure alone.Results Using 50 bar of water pressure resulted in the best balance between proper dissection and view-disturbing water backflow. The dissection speeds for the lower, middle, and upper esophagus were 0.2, 0.9, and 0.2 cm2/min in 50 bar WJ-ESD and 1.1, 0.5, and 1.0 cm2/min in C-ESD, respectively. Minor bleeding was frequent in WJ-ESD, but was easily stopped by electrocoagulation with the same needle. No perforation was observed in either procedure. Thermal damage to dissected tissues appeared mild, and the extent of muscle injury was lower for WJ-ESD (4, 6, and 8 %) compared with C-ESD (14, 16, and 7 %).Conclusions WJ-ESD could be completed safely for porcine esophagus with less damage to the muscle layer compared with C-ESD

Risk Factors for Bleeding After Endoscopic Submucosal Dissection for Gastric Cancer in Elderly Patients Older Than 80 Years in Japan.

Introduction:As the aging of people in a society advances, the number of elderly patients older than 80 years in Japan with gastric cancer continues to increase. Although delayed ulcer bleeding is a major adverse event after endoscopic submucosal dissection (ESD), little is known about characteristic risk factors for bleeding in elderly patients undergoing ESD. This study aimed to evaluate risk factors for delayed bleeding after ESD for gastric cancer in elderly patients older than 80 years.Methods:We retrospectively evaluated the incidence of delayed bleeding after ESD in 10,320 patients with early-stage gastric cancer resected by ESD between November 2013 and January 2016 at 33 Japanese institutions and investigated risk factors for delayed bleeding in elderly patients older than 80 years.Results:The incidence of delayed bleeding in elderly patients older than 80 years was 5.7% (95% confidence interval [CI]: 4.6%-6.9%, 95/1,675), which was significantly higher than that in nonelderly (older than 20 years and younger than 80 years) patients (4.5%, 4.1%-5.0%, 393/8,645). Predictive factors for ESD-associated bleeding differed between nonelderly and elderly patients. On multivariate analysis of predictive factors at the time of treatment, risk factors in elderly patients were hemodialysis (odds ratio: 4.591, 95% CI: 2.056-10.248, P < 0.001) and warfarin use (odds ratio: 4.783, 95% CI: 1.689-13.540, P = 0.003).Discussion:This multicenter study found that the incidence of delayed bleeding after ESD in Japanese patients older than 80 years was high, especially in patients receiving hemodialysis and taking warfarin. Management of ESD to prevent delayed bleeding requires particular care in patients older than 80 years

Performance Test of a Medium Consistency Centrifugal Slurry Pump in an Actual Fiber-Suspension-Flow (Availability of the Water Tests)

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