Long-term effects of interstitial laser coagulation in porcine liver with portal inflow occlusion: Central versus peripheral lesions

PURPOSE: Interstitial laser coagulation (ILC) is an attractive modality for local destruction of unresectable hepatic metastases. Portal inflow occlus ion considerably increases its destructive capacity, resulting in lesions 5 cm in diameter; however, effects on adjoining major intrahepatic structure s are unknown. Therefore, the purpose of this study was to assess the effec ts of ILC with portal inflow occlusion on the central portion of the liver as compared to the peripheral portions. MATERIALS AND METHODS: ILC was performed in pigs with portal inflow occlusi on, Each animal received a single laser application with Nd:YAC: light guid ed simultaneously through four interstitial fibers with 5 W per fiber durin g 6 minutes. Location of treatment was randomized to either central (n = 8) or peripheral (It 8), Follow-up was for 1, 2, or 3 months with evaluation of liver functions and weight, as well as macroscopic and microscopic asses sment of coagulated lesions and surrounding parenchyma, RESULTS: There was no treatment-related morbidity or mortality. No obstruct ive cholestasis or bile leakage was found. At every moment of evaluation, c oagulated volumes in the central group were smaller than in the peripheral lesions (P = .03), Large vessels contiguous to the lesions in the central g roup were always intact and indications of portal hypertension or thrombosi s of hepatic veins were not found. There were no significant differences be tween the two groups (liver functions [P greater than or equal to .15] and weight [P = .69]), CONCLUSION: ILC with portal inflow occlusion is a safe technique in the vic inity of vital structures in the liver of healthy pigs, These results justi fy studies to the feasibility and complication rate of portal inflow occlus ion in patients with hepatic malignancies.