The Acute Effects of Transthoracic Cryoablation on Normal Lung Evaluated in a Porcine Model

Purpose Percutaneous transthoracic cryoablation of lung parenchymal tumors offers a potentially less invasive alternative to thoracoscopic tumor resection. In the present study, we investigated the feasibility of transthoracic cryoprobe insertion into the lung parenchyma. Description Cryoablation was performed in porcine lung through a thoracotomy. A 2-mm diameter cryoprobe was inserted to a depth of 3 cm from the pleura. Cryoablation was performed as one or two cycles of 15-minute freeze followed by 5-minute thaw. Bleeding time and amount, and air leakage pressure from the insertion site was measured and compared between cycles. Evaluation The bleeding time and amount significantly increased, and air leakage pressure significantly decreased with two cycles of cryoablation compared with one cycle. Histologically, the primary finding in the cryolesion was localized pulmonary hemorrhage. Conclusions Bleeding time, bleeding amount, and air leakage from the insertion site after two cycles (453 ± 202 s, 1.3 ± 0.6 g, and 28 ± 12 cm H2O, resectively) were considered unlikely to cause acute serious complications. Although long-term studies are needed, the present study provides support for transthoracic cryoablation.