Percutaneous cryoablation of adrenal metastases: technical feasibility and safety

Purpose To assess the technical feasibility and outcomes of adrenal metastases cryoablation. Materials and methods This is an IRB approved retrospective review of adrenal metastases cryoablation between April 2003 and October 2018. Forty percutaneous cryoablation procedures were performed on 40 adrenal metastases in 34 patients. Histology, tumor size, ablation zone size, major vessel proximity, local recurrences, complications, and anesthesia-managed hypertension monitoring was collected. Complications were graded according to the Common Terminology of Complications and Adverse Events (CTCAE). Results Mean tumor and ablation size was 3.2 cm and 5.2 cm, respectively. Local recurrence rate was 10.0% ( N = 4/40) for a mean follow-up time of 1.8 years. Recurrences for tumors > 3 cm (21.0%, N = 4/19) was greater than for tumors ≤ 3 cm (0.0%, N = 0/21) ( p = 0.027). Proximity of major vasculature (i.e., IVC & aorta) did not statistically effect recurrence rates ( p = 0.52), however, those that recurred near vasculature were > 4 cm. Major complication (≥ grade 3) rate was 5.0% ( N = 2/40), with one major complication attributable to the procedure. Immediate escalation of blood pressure during the passive stick phase (between freeze cycles) or post procedure thaw phase was greater in patients with residual adrenal tissue ( N = 21/38) versus masses replacing the entire adrenal gland ( N = 17/38), ( p = 0.0020). Lower blood pressure elevation was noted in patients with residual adrenal tissue who were pre-treated with alpha blockade ( p = 0.015). Conclusions CT-guided percutaneous cryoablation is a safe, effective and low morbidity alternative for patients with adrenal metastases. Transient hypertension is related only to residual viable adrenal tissue but can be safely managed and prophylactically treated.