Percutaneous Image-Guided Cryoablation of Challenging Mediastinal Lesions Using Large-Volume Hydrodissection: Technical Considerations and Outcomes.

Abstract

This study was designed to describe the technique of percutaneous image-guided cryoablation with large-volume hydrodissection for the treatment of challenging mediastinal lesions. Between March 2014 and June 2015, three patients (mean age 62.7years) with four neoplastic anterior mediastinal lesions underwent five cryoablation procedures using large-volume hydrodissection. Procedures were performed under general anaesthesia using CT guidance. Lesion characteristics, hydrodissection and cryoablation data, technical success, complications, and clinical outcomes were assessed using retrospective chart review. Lesions (mean size 2.7cm; range 2-4.3cm) were in contact with great vessels (n=13), trachea (n=3), and mediastinal nerves (n=6). Hydrodissection was performed intercostally (n=4), suprasternally (n=2), transsternally (n=1), or via the sternoclavicular joint (n=1) using 1-3 spinal needles over 13.4 (range 7-26) minutes; 450ml of dilute contrast was injected (range 300-600ml) and increased mean lesion-collateral structure distance from 1.9 to 7.7mm. Vulnerable mediastinal nerves were identified in four of five procedures. Technical success was 100%, with one immediate complication (recurrent laryngeal nerve injury). Mean follow-up period was 15months. One lesion demonstrated residual disease on restaging PET-CT and was retreated to achieve complete ablation. At last follow-up, two patients remained disease-free, and one patient developed distant disease after 1year without local recurrence. Cryoablation using large-volume hydrodissection is a feasible technique, enabling safe and effective treatment of challenging mediastinal lesions.