Percutaneous MR-Guided Cryoablation of Low-Flow Vascular Malformation: Technical Feasibility, Safety and Clinical Efficacy.

PURPOSE: To retrospectively assess the technical feasibility, safety and clinical efficacy of percutaneous MR-guided cryoablation of low-flow vascular malformations (LFVM). MATERIALS AND METHODS: Between July 2013 and May 2019, 9 consecutive patients (5 male; 4 female; mean age 39.4 +/- 15.3 years, range 15-68) underwent MR-guided cryoablation of LFVM. Patients were treated due to pain in all cases. Procedural data, complications and clinical results were analyzed. RESULTS: Technical success defined as complete coverage of the LFVM by the iceball without involvement of nearby non-target thermal-sensitive structures was achieved in 9/9 (100%) cases. Mean procedure time was 122 +/- 20 min (range 90-150); 2-6 cryoprobes (mean 3.7 +/- 1.2) and 2-4 freezing cycles (mean freezing time 19.8 +/- 11.8 min; range 4-40) were applied. No complications were noted. Mean time from the first treatment to the last follow-up was 548 days (range 30-1776). Persistent/recurring pain was noted in 3/9 cases (33%) 30, 133 and 639 days after cryoablation, respectively, and was related in all cases to MR-confirmed local residual/recurring disease. A second cryoablation treatment was performed in these 3 cases with complete pain control at the last available follow-up (153, 25, 91 days, respectively). In the whole population, at mean 161 days (range 25-413) after the last treatment, on the numerical pain rate scale, pain significantly dropped from mean 6.4 +/- 2.1 (range 3-9/10) before CA to mean 0.3 +/- 0.9 (range 0-3/10) after (p = 0.009). CONCLUSIONS: Percutaneous MR-guided cryoablation is technically feasible, safe and effective for the treatment of symptomatic LFVM. LEVEL OF EVIDENCE: Level 3b, retrospective cohort study.