Laparoscopic thermal ablation of hepatic neuroendocrine tumor metastases

Neuroendocrine tumor metastases to the liver are generally slow growing, but patients suffer from hormone hypersecretion despite aggressive multimodality therapy. A minimally invasive method of tumor ablation affords symptomatic improvement with minimal morbidity.

Radiofrequency electrical energy is delivered to tissues via a 4-prong catheter resulting in tissue heating to 60 to 70 degrees C and cell death. Porcine studies were conducted to define appropriate parameters for energy delivery and then applied to patients using laparoscopic techniques.

In the porcine model 3.5 to 4 cm lesions were reproducibly created in 15 minutes using 30 to 50 W of power. The ablation process was monitored via temperature feedback from thermocouples in the catheter tips and by a hyperechoic blush noted on ultrasonography. Laparoscopic thermal ablation of 13 tumors in six patients with carcinoid (two patients), gastrinoma, insulinoma, nonsecreting islet cell cancer, or medullary thyroid cancer was performed. There were no intraoperative complications, and all patients were discharged the next day. Successful ablation was confirmed by spiral-computed tomography and by symptomatic improvement in patients with secreting tumors.

Laparoscopic thermal ablation of hepatic tumors is a novel, minimally invasive method of providing effective cytoreduction of neuroendocrine tumors metastatic to the liver.