Holmium laser ablation of porcine pancreas in vitro / 中华胰腺病杂志

ABSTRACT

Objective To investigate the effects of different energy,frequency and time of holmium laser on the ablated porcine pancreas in vitro,and to establish an ablation regression equation of holmium laser,in order to provide the experiment foundation for EUS-guided holmium laser ablation of pancreatic carcinoma.Methods According to pilot study,the range of energy,frequency and time of holmium laser was determined,and five values were chosen for the individual three parameters,therefore,a randomize table including 125 combinations (sample capacity) according to the various combinations of every parameter was constructed,then every combination of holmium laser was used for porcine pancreas ablation in vitro.EUS was applied to determine the ablation site and measure the ablation extent,and pathological evaluation was performed.Results Sonographic images showed hyperechoic cloudy area in the ablation site.It was observed that the ablation body was an approximately oval area,the middle part was carbonized area,and the out layer was grey-white necrosis area.Microscopic examination showed there was pool-like cavity in the middle of ablation site,and it was surrounded by coagulation necrosis of pancreatic tissue,and the out layer was inflammatory cells infiltration.Normal pancreatic tissue was found in the margin.The energy,frequency and time of hoimium laser were positively associated with the ablation extent,and the frequency was the main factor,followed by time and energy.The difference was statistically significant (P＜O.O1).The best combination was 25 s,25 Hz,1.8 J.An ablation regression equation was created,which was In (ablation volume) =β0 + β1 × time + β2 × frequency + β3 × energy.Conclusions The holmium laser can produce obvious tissue necrosis in porcine pancreas in vitro; the established holmium laser ablation regression equation can be the guidance for clinical practice.