IMPORTANCE OF ELIMINATING PORTAL FLOW TO PRODUCE LARGE INTRAHEPATIC LESIONS WITH INTERSTITIAL LASER COAGULATION

Background Interstitial laser coagulation is a local treatment modalit y for solid tumours, such as liver metastases. Perfusion by the vascul ar system can transfer heat from the treatment site, thereby reducing the volume of destroyed tissue. Methods This effect was investigated i n a pig model (n = 10). Lesions were produced in the liver with four i nterstitial laser fibres (5 W per fibre for 6 min): (1) with flow thro ugh the liver (n = 9); (2) with the portal vein clamped (n = 8); and ( 3) with both hepatic artery and portal vein clamped (n = 6). The pigs were killed and the liver was dissected; lesions were assessed macrosc opically and microscopically. Results The volume of the lesion was sig nificantly larger when portal flow was eliminated (30.6 versus 6.4 cm( 3), P < 0.001). Conclusion Hepatic blood flow substantially reduces th e size of the lesion produced by laser coagulation. Portal flow should therefore be occluded during laser treatment to produce lesions of cl inically relevant dimensions.