V5-14: Percutaneous gas-cooled microwave ablation for small renal masses: the Mount Sinai experience
VideoIntroductions and Objectives
Microwave ablation (MWA) is a novel thermal treatment modality for the definitive management of small renal masses (SRM). In pre-clinical models, proposed advantages include higher treatment temperatures, improved thermal gradient and larger effective areas. We present the technical considerations and institutional technique for the management of selected patients with SRMs.
Patients with enhancing renal masses treated with microwave ablation and coaxial biopsy between 2011 and 2013 at our institution were included in this series. Tumor histopathology, nephrometry score, post-procedural complications, radiographic evidence of resolution, defined as non-enhancement and necrosis on follow up imaging, were recorded.
MWA was performed in 23 patients using real time computerized tomography (CT) to and simultaneous coaxial renal biopsy and ablation. Mean patient age was 63 years (range 39-81), and mean tumor diameter was 2.3cm (range 0.7-3.8). A 2.45 GHz microwave probe was utilized at energies of 50-65 Watts, reaching therapeutic temperatures of 112 degrees Celsius. Techniques employed included trans-hepatic antenna placement, cystoscopy and catheter placement for retrograde pyeloperfusion in central tumors, and hydrodissection with iodinated contrast. There were no intraoperative complications, and all patients were admitted for overnight observation; one patient required angiography and embolization for a treatment-related pseudoaneurysm. On follow up, non-enhancement and necrotic cavity formation was demonstrated in 22/23 (95.6%) of individuals.
MWA is an emerging ablative technology that is safe and efficacious for the management of SRM in non-surgical candidates. Longitudinal follow is required to assess the oncologic and functional outcomes of this modality.