Evaluation of carbon dioxide thermal protection over neural structures of the spine canal of porcine models treated by computed tomography/fluoroscopy guided percutaneous vertebral cryoablation: radiological-anatomopathological correlation

Abstract

Metastatic bone lesions are common, mainly from breast, lung and prostate cancer. These lesions are often painful, regardless their density, either osteolytic or sclerotic. Palliative treatment includes opioid analgesia and/or external beam radiation therapy, whenever surgical resection is not achievable. Alternatively, excellent results have been reported with minimally-invasive treatments such as percutaneous radiofrequency ablation of osteolytic lesions followed by cementoplasty. However, while radiofrequency ablation energy is poorly delivered into sclerotic or otherwise intact bòne, cryoablation will effectively treat intact or sclerotic bone. Percutaneous cryoablation is thus a therapeutic option that can afford good results to treat pain from sclerotic vertebral metastases. One of the conditions to perform it safely is to avoid proximity of the treated area with neural structures from the spine canal. The procedure carries the risk of thermal lesions resulting in neural harm. Thermal insulating techniques may allow cryoablation treatment of sclerotic metastases near the spine canal, without greater risk to neural structures. Carbon dioxide can be used as an efficient insulator by its physical properties. The aim of this work is to evaluate protective effects of carbon dioxide epidural injection over neural structures of the spine canal from porcine models treated by computed tomography/fluoroscopy guided percutaneous vertebral cryoablation. (AU)