Percutaneous Image-Guided Cryoablation in Vascular Anomalies

Sclerotherapy, cryoablation, and surgical fixation of an intraosseous tibial venous malformation

Intraosseous vascular malformations are rare vascular anomalies that present unique treatment challenges due to structural instability, embolization and sclerotherapy resistance, and tendency to recur. Patients may have clinical manifestations including pain, functional impairment, increased fracture risk, and decreased quality of life. Image-guided ablation techniques are emerging interventional treatment options for soft tissue tumors and complicated vascular anomalies. Percutaneous image-guided cryoablation offers a potential alternative as an isolated or adjunct therapy for intraosseous vascular malformations.

Cryoablation for Bone and Soft Tissue Lesions in Pediatric Patients: Complications and Preventive Measures

PURPOSE

To evaluate complications associated with cryoablation in a pediatric population and review preventive measures to mitigate these complications.

MATERIAL AND METHODS

Retrospective study including all the image guided cryoablations performed on pediatric population. Immediate and delayed complications were analyzed, and we identified the different protective measures used and the clinical outcomes from follow-up. Point estimates for the percentage of complications were calculated by maximum likelihood, and 95% confidence intervals for the true percentages were calculated using the Clopper-Pearson exact method.

RESULTS

Eighty-seven ablations were performed on 68 patients (age range of 2-18 years, mean 12.4 years) for non-neoplastic (70%) and neoplastic (30%) lesions. The percentage of ablations resulting in complications was 18% (95% confidence interval (CI) 11% to 28%). Of these, 5% (95% CI 1% to 11%) were grade 3 complications, and 14% (95% CI 7% to 23%) were grade 2 complications. Thermal protection was performed in 27.6% of ablations (n = 24). The mean clinical follow-up duration was 348 days.

CONCLUSION

Cryoablation in pediatric patients is relatively safe, with a major complication rate per ablation of 5%. Thermal protective measures can be considered to mitigate these complications.

Management of Venous Malformations

Venous malformations (VMs) are slow-flow, congenital vascular anomalies that are a result of vascular dysgenesis. Clinical presentation and morbidity depend on size, location, and association with other syndromes. VMs are the most common symptomatic vascular anomaly referred for intervention, usually due to thrombosis, swelling, mass effect, functional compromise, or cosmetic concerns. Treatment for larger lesions can be challenging and a multidisciplinary approach involving medical, interventional, and surgical input is critical for comprehensive care. This article will assist the interventional radiologist in patient assessment and will discuss current techniques for treatment, means to minimize adverse events, and expected outcomes.

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.