Laparoscopic radiofrequency ablation of primary and metastaticliver tumors

Abstract

Background: Radiofrequency thermal ablation is a new technology for the local destruction of liver tumors. Since we first described laparoscopic radiofrequency ablation (LRFA) for the treatment of liver tumors, much has been learned about patient selection, laparoscopic ultrasound (LU) guided placement of the ablation catheter, monitoring of the ablation process, and patient follow-up.

Methods: Since January 1996 we have performed LRFA of 250 tumors in 67 patients including 85 adenocarcinomas, 107 neuroendocrine tumors, 34 sarcomas, 1 melanoma, and 11 hepatomas. We used LU to guide placement of the ablation catheter and to monitor the ablation process. Most of the patients had two trocars (camera and laparoscopic ultrasound) with the 15-gauge ablation catheter (RITA Medical Systems, Mountain View, CA, USA) placed percutaneously.

Results: The LRFA procedure was completed successfully in all patients, with 1 to 14 lesions per patient, ranging in size from 0.5 to 10 cm in diameter. The entire liver could be examined by LU via right subcostal ports. Criteria for successful ablation were 5-min ablation times at 100°C with 1-min cool-down temperatures of 60° to 70°C. Outgassing of dissolved nitrogen, monitored by ultrasound, was useful in confirming the zone of ablation. Intralesional color-flow Doppler, seen before ablation, was eliminated after ablation. Placement of the grounding pad closer to the lesion on the back rather than the thigh resulted in more efficient energy delivery to the tumor. Lesions larger than 3 cm in diameter required overlapping ablations to achieve a 1-cm margin of normal liver. Most patients required overnight hospitalization, with no coagulopathy or electrolyte disturbances noted.

Conclusions: The LRFA procedure is a novel, minimally invasive technique for treatment of liver tumors that have failed conventional therapy. This study documents the technical aspects of targeting lesions and performing reproducible zones of ablation. Familiarity with these techniques should lead to more widespread application.