Development and validation of an experimental model for the assessment of radiofrequency ablation of pancreatic parenchyma.

OBJECTIVES

The aim of this study was to develop and validate an ex vivo model for the assessment of radiofrequency (RF) ablation of the pancreas.

METHODS

Porcine pancreata were used within 1 hour of sacrifice. RF was delivered to a premarked area in the center of the pancreatic head using a thermocouple-tipped multiprobe array. Four temperature presets were evaluated: 70 degrees-100 degrees C in 10 degrees increments. Immediately after ablation serial sections of the pancreatic head were cut to incorporate duodenum, portal vein, and bile duct. For each experiment, a portion of pancreatic tail was sampled as nonablated control. Hematoxylin and eosin (H&E) slides together with nicotinamide adenine dinucleotide (NADH) stained preparations were made. The NADH staining was quantified using computerized digital image recognition techniques.

RESULTS

Control sections (n = 20) demonstrated normal pancreatic architecture on H&E and strong NADH staining indicating preserved tissue oxidative metabolism. RF produced a temperature-dependent destruction of parenchymal architecture (H&E) with a corresponding loss of NADH activity. There was no evidence of thermal injury to the duodenum. Quantification of NADH staining demonstrated a median positive staining of 69.26% (55.87-97.28) for control tissue compared with 1.40% (0-7.77) for ablated pancreas (P < 0.001; Mann-Whitney U test).

CONCLUSION

This study describes the development of a relatively simple, reliable, and reproducible model for evaluation of RF ablation of pancreatic parenchyma.