Determination of optimal monopolar coagulation settings for upper GI bleeding in a pig model

BackgroundMonopolar electrocautery has had a limited role in the endoscopic therapy of nonvariceal upper GI bleeding because of the lack of specifically designed endoscopic instruments and limited data on how to use this technology for endoscopic applications.ObjectiveTo determine the optimal power settings and durations of endoscopic monopolar electrocautery for nonvariceal gastric bleeding.DesignTwelve pigs underwent creation of cautery lesions by using a novel monopolar electrocautery device designed for endoscopic hemostasis control. The efficacy as measured by the depth of cautery and safety of monopolar electrocoagulation were evaluated in acute and survival phases.InterventionsMonopolar electrocautery was applied to the stomach with power settings of 25, 50, and 75 W for durations of 2 to 5 seconds.Main Outcome MeasurementThe extent of cautery injury was assessed histologically by a blinded pathologist.ResultsAn optimal cautery effect was achieved with 50 W of power and durations of cautery of 2 and 3 seconds. For 25 W, durations of cautery of 4 and 5 seconds resulted in good but often superficial cautery effect. For 75 W, durations of cautery of 2 and 3 seconds resulted in good cautery effect, but with marginal safety. The visual diameter of monopolar cautery lesions correlated with the histological depth of the cautery lesions. No adverse effects were observed.LimitationsStudy conducted in a nonbleeding pig stomach model; thus, results may not apply to control of GI bleeding in patients.ConclusionsBased on a nonbleeding pig model, we suggest that the initial settings for monopolar soft coagulation in clinical use should be 50 W for 2 to 3 seconds.