Work

Percutaneous Microwave Ablation of Small (<4 cm) Renal Masses Performed under Moderate Sedation

Year: 2025

Type: article

Abstract: PURPOSE: To determine the technical success, adverse events, local tumor recurrence, and survival in adult patients undergoing microwave ablation (MWA) of small renal masses performed exclusively under moderate sedation. MATERIALS AND METHODS: A single-institution, retrospective review from 2016 to 2023 of percutaneous, computed tomography-guided MWA for small renal masses (<4 cm) was performed. After addressing exclusion criteria, 66 patients undergoing 72 ablations were included. Patient demographics, comorbidities, tumor characteristics, procedural details, and clinical outcomes were evaluated. Kaplan-Meier analysis of progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS) was performed. Kidney function before and after ablation was compared using the nonparametric Mann-Whitney U test. RESULTS: Seventy-two small renal masses with a mean size of 2.2 cm (SD ± 0.7) underwent MWA with a 2.45-GHz gas-cooled MWA system at 65 W for 5-15 minutes (mean, 39.1 kJ) performed under moderate sedation. Demographics included a mean age of 68.4 years (SD ± 8.3) (n = 62 men) and Charlson Comorbidity Index score of 6.2 (SD ± 2.1). Median sedation doses were 150 mcg (interquartile range [IQR], 100-175 mcg) of fentanyl and 2.5 mg (IQR, 2-3.5 mg) of midazolam. Technical success was 100%, and all patients were discharged the same day. Median follow-up duration was 3.1 years. PFS and OS were 88.1% and 91.9% at 3 years, respectively. CSS was 100%. There were 2 mild adverse events (2.8%) and 3 recurrences (4.2%). Only 9.7% (n = 5) of patients required postprocedural analgesia; no patients required postdischarge analgesic prescriptions. CONCLUSIONS: MWA of small renal masses under moderate sedation alone demonstrates excellent patient safety profile, tolerability, and effectiveness, allowing operational efficiency, including short procedure times and same-day discharge.

Source: Journal of Vascular and Interventional Radiology

DOI: 10.1016/j.jvir.2025.03.024