The New Wave of Treatment: Review of Percutaneous Thermal Ablation for Treating Low-Flow Vascular Malformations

1. Review percutaneous thermal ablation for the management of low-flow vascular malformations (LFVM) including indications, techniques, and data supporting its use as a first- or second-line therapy.
2. Understand the advantages and disadvantages of thermal ablation compared with alternatives including sclerotherapy, embolization and surgery for the treatment of LFVM.

Background: There is growing evidence supporting the use of percutaneous ablation for the treatment of LFVMs. {1} While LFVM are benign, they may be associated with pain, compression of adjacent structures, deformity, and impact quality of life. Percutaneous therapy for LFVM is a minimally invasive, safe, and efficacious treatment option.

Clinical Findings/Procedure Details:

Sclerotherapy is a non-thermal percutaneous treatment modality that is often the first line treatment for LFVM. Not all LFVM are amenable to percutaneous sclerotherapy due to location and poor visualization of targetable vascular channels or predominance of solid components in the lesion.  In addition, some LFVM may be refractory to sclerotherapy or it may provide limited symptomatic relief. Percutaneous thermal ablation is emerging as an effective treatment both for initial treatment and as second-line treatment for refractory or recurrent lesions.

Cryo-, radiofrequency, and microwave ablation have all been used to treat LFVM. Ablation is performed under general anesthesia or conscious sedation. After lesion localization using the imaging modality of choice, the thermal applicator(s) are positioned in the target lesion. Ablation is performed using manufacturer protocols. Cryoablation allows the operator to monitor the ice ball during ablation. The moving shot technique with radiofrequency ablation and sonographic guidance has more recently been applied in this setting and offers the benefit of real time assessment of the ablation zone and reduced risk of injury to adjacent structures compared to a fixed applicator position. {2, 3}

 
All ablation modalities require stringent patient selection based on lesion location and local anatomy. The safety profile of thermal ablation has been improved using methods like hydrodissection or pneumodissection to avoid nerves and other nearby structures. {4, 5} Pre-procedure imaging to aid in patient selection is critical to improving patient outcomes. {6}

Conclusion and/or Teaching Points: Percutaneous thermal ablation is a safe and efficacious technique for the management of LFVM.