The Feasibility And Efficiency Study Of Isopentane For Submucosal Lift During Endoscopic Resection

BackgroundWith the development of endoscopic technology in diagnose and treatment,more and more early lesions of gastrointestinal tract could be detected.These lesions could be treated by endoscopic musocal resection(EMR)or endoscopic submucosal dissection(ESD).These minimally invasive treatments have been proved effective and safe.Mucosal lift is the critical step for successful endoscopic treatment.Normal saline(NS)is widely used as the submucosal filler,but its short persistency restricts clinical ESD procedure.And also increase the complications.In this study,thermo-sensitive isopentane was introduced for submucosal injection.With 27.8 ?boiling point,liquid isopentane could be easily applied.Isopentane would be gasified when injected into submucosa,while gasification inflation could provide great support for submucosal lifting at body temperature.This process would provide support for submucosal cushion.The feasibility,efficiency and safeness of isopentane were evaluated in this study.MethodsIn the first stage,the porcine stomachs were introduced for in vitro evaluation.37? water bath was applied to mimic body temperature.Compared with NS,isopentane was studied for its lifting performance,including injection dosage,lifting strength persistency and efficacy for assisting submucosal dissection.In vitro simulation experiments of ESD were performed Same area of mucosa was dissected and the time used of each groups were recorded.The submucosal tissue changes were also compared.In the second stage,for in vivo evaluation,rats were applied to further compare the difference between isopentane and NS,including the lifting efficacy,pathological effect and safety.ResultsAs the in vitro experiments showed,compared with NS,the maximum lifting height could be achieved by less isopentane(2%NS volume).Longer persistency and faster operation for submucosal dissection were also recorded for isopentane during in vitro study.Aerification could result in the vacuolization of submucosal connective tissue,which would facilitate endoscopic mucosal resection and postoperative recovery.The same results were confirmed in the rat model.With the same dosage,isopentane led to a better mucosal elevation and larger lifting range than NS.According to histological examination,no tissue injury was observed with isopentane application.ConclusionsAs submucosal injection agent,the feasibility,efficacy and safety of isopentane were demonstrated.Thermo-sensitive aerification would be a promising approach to facilitate ESD and worth further researches.