Effect Of The Operating Parameters Of Electrosurgical Unit On The Sealing Of Porcine Pancreatic Duct

Nowadays,effective prevention and treatment of pancreatic fistula is a difficulty and research hotspot in pancreatic surgery.Currently most surgeons prevent pancreatic fistula mainly by means of their excellent surgical skills rather than using energy surgical systems in clinic.The thermal effect of electrosurgical unit(ESU)can cause cell rupture,tissue vaporization,and degeneration of protein condensation,then leading up to the sealing of some pancreatic ducts without suturing and then the formation of eschar on pancreatic section so as to realize hemostasis and prevent pancreatic fistula.The formation of eschar is closely associated with the operating parameters of ESU,but the relationship between them is not clear.So,surgeons cannot effectively use ESU to prevent pancreatic fistula.Therefore,it is really necessary to study the influence of operating parameters on the sealing of pancreatic duct,which would provide valuable insight to the application of ESU in the prevention of pancreatic fistula and further optimal design of energy surgical systems.In this study,ex vivo porcine pancreas was used as tissue sample.The influences of operation mode,output power and action time of ESU on the sealing of porcine pancreatic duct and the thermal damages of pancreas tissue were investigated using a self-designed ESU test device,aiming to reveal the sealing mechanism of porcine pancreatic duct and key factors.Mechanical testing,morphology and composition characterization and histological analysis were performed.Main results and conclusions were drawn as follows:(1)The operation mode of ESU had an influence on the structural characteristics of eschar on pancreatic section and then affected the sealing of pancreatic duct.In SPRAY mode,the eschar with many big through-holes was formed on pancreatic section accompanied with a deep tissue thermal damage,then causing a low burst pressure of pancreatic duct so as not to prevent pancreatic fistula.In both DESICCATE and FULGURATE mode,with specific output power and action time,the eschar with a multi-layer structure consisting of loose outer surface layer and compact inner layer could be formed,which could result in an enough high burst pressure of pancreatic duct to prevent pancreatic fistula.With a same burst pressure,the degree of pancreatic tissue thermal damage is lower in DESICCATE mode than in FULGURATE mode.(2)It was found that in DESICCATE mode,there was an optimal energy output range,in which the burst pressure of porcine pancreatic duct was high enough to prevent pancreatic fistula.When the output power was 60 W and the action time was 2 s,the sealing effect of the pancreatic duct was the best.The eschar against pancreatic fistula should have both a multilayer structure consisting of loose outer surface layer and compact inner layer and a certain thichness.The optimum thickness of eschar was found to be about 600 ?m.(3)The variation of the binding strength between the electrode-eschar interface and the eschar-tissue interface with the output power and action time of ESU was studied in DESICCATE mode.The range of operating parameter which could prevent eschar from detachment caused by intraoperative adhesions was provided.