90th Annual Meeting Abstracts
Incidence of Hepatic Vein Thrombus (HVT) after Microwave Ablation (MWA) of Hepatic Tumors
*David Sindram, MD PhD, *Ajita S Prabhu, MD, *Srikanth Padma, MD, *John B Martinie, MD, David A Iannitti, MD
Carolinas Medical Center, Charlotte, NC
Objective: MWA has emerged as an effective intervention for unresectable hepatic tumors. A concern of ablation has been potential association with HVT, however the incidence of HVT after MWA has not been described to date. The objective of this study was to determine the incidence of post-MWA HVT.
Design: Retrospective analysis of prospective database.
Setting: Academic tertiary referral center
Patients: All patients with hepatic tumors undergoing MWA with available follow-up tri-phase CT.
Interventions: MWA of hepatic tumors using 915 MHz or 2.45 GHz MWA system
Main Outcome Measures: Patient demographics, tumor size, presence or absence of HVT, number of antennae used
Results: 42 patients (24 males); mean age 57.4 years (range, 33-78 years). 122 MWA, 80 with 915 MHz and 42 with 2.45 GHz systems, respectively. Mean±SEM tumor size was 1.98±0.13 cm (range 0.3-7 cm). Five patients underwent chemoembolization and 3 yttrium microsphere therapy treatments prior to ablation. Mean±SEM number of antennae per tumor was 3.09±0.44 (range 1-30) for the 915 MHz and 1.46±0.14 (range 1-5) for the 2.45 GHz system. Followup CT scans were obtained at mean 26 days (mode 31 days, range 1-51 days). Two patients (4.6%), ablated with the 2.45 GHz system, had HVT on post-ablation CT scans. One patient, pretreated with yttrium microsphere therapy, underwent 5 ablations and resection of segments 2 and 3. The other patient, pretreated with chemoembolization, underwent 1 ablation. Both patients were anticoagulated upon discovery of HVT.
Conclusions: In this cohort, MWA was associated with clinically silent HVT in 4.6%. Post-ablation CT scans should be reviewed with great care for potential HVT. Preclinical studies are ongoing to determine HVT incidence during RFA and MWA around hepatic veins.