Effect Of Gastrointestinal Mucosal Damage And Homeostasis Of Mesenteric Vascular Bleeding On Rabbits With Argon Plasma Coagulation

Objectives: The main aim of this study was to investigate the effect of gastrointestinal mucosal damage and mesenteric vascular homeostasis on Zelanian rabbits with homemade argon plasma ancoagulator and offer reasonable power and argon gas flow (AGF) settings for clinical practice.Methods: Argon plasma coagulation (APC) was performed on Zelanian rabbits esophagus, stomach and colon with the homemade argon plasma coagulator system at different combinations of argon gas flow (AGF), power (Pow), angle, pulse duration and probe tissue separation. The basic parameter was determined when a coagulation arc was seen. A scoring system for depth of tissue damage was created. Specimens were evaluated by microscopy, functional ultra - microscopy analysis system and endoscopic mini-sonoprobe ultrasound.Two groups of mesenteric vessels (diameter less than 1 mm and from 1 mm to 1.9mm) were coagulated with power 30w, 40w, 60w and 80w. Haemostatic rate and duration were recorded for statistical analysis. With the ideal haemostatic powersettings (40 w, 60 w) , the gastric ulcer bleeding caused by biopsy forceps were treated with APC compared with Ho: YAG laser (power 5 w, pulse 10/second). The haemostatic duration and depth of tissue damage were evaluated.Results: The minimum powers required to produce a coagulation arc at 1mm probe tissue separation for different AGF were as follows: 2.0L/min AGF, 20w; 2. 5L/min AGF, 15w; 3. 0L/min AGF, 10w; 4. OL/min AGF, 5w. The coagulation arc was found at 2mm probe tissue separation with 80w power setting. The depth of tissue damage was related to power setting (except esophagus) , AGF and pulse duration (P<0. 05) but not to the angle between the catheter and tissue (P>. 05) . The depth of tissue damage reached muscularis propria in colon, and submucosa in oesophagus and stomach without perforation.With vascular diameter less than 1 mm, the nemos tatic rate was 53. 3% in 30w power setting, 93% in 40w power setting and 100% in 60w or more power setting respectively. The effectivc homeostasis was only found in 60w or more power setting with vascular diameter between 1 mm and 1.9 mm. Compared with Ho: YAG laser, APC had shorter homeostatic duration and milder tissue damage (P<0. 05) .Conclusions: The depth of tissue damage was under control in safe selection of power setting without perforation. Good effect of homeostasis of APC was confirmed with 40w to 60w power setting in vascular diameter less than 1 mm. Compared with Ho: YAG laser, the hemostatic effect of APC on gastriculcer bleeding was more effective.