[Evaluation of cardio-pulmonary function for lobectomy under the condition of selective pulmonary arterial occlusion test (SPAO)].

We performed selective pulmonary arterial occlusion test (SPAO) and unilateral pulmonary arterial occlusion test (UPAO) in 30 patients with lung cancer who would be undertaken right lower lobectomy or middle and lower lobectomy, and evaluated the preoperative cardio-pulmonary function. The lung hemodynamics during SPAO were different from those during UPAO. This indicates that SPAO evaluated reserve capacity of vascular bed in the right upper lobe which would be remained at the surgery. Moreover, the ratio of total pulmonary vascular resistance during SPAO to that of before SPAO was not differed in two groups, one was a group with and the other was a group without impaired reserve capacity of vascular bed in the contralateral lung. This suggests that reserve capacity of pulmonary vascular bed including right upper lobe would be well compensated even in the patients with highly impaired capacity in the contralateral lung. Based on these findings, we performed lung resections in 9 patients, who were judged contraindications for lung resection by the results of UPAO, and no patient suffered postoperative cardio-pulmonary complications. Total pulmonary vascular resistance immediately after the right middle and lower lobectomy were equal to those during SPAO. Thus we conclude that SPAO is very useful technique for evaluating cardiopulmonary function after right lower lobectomy or middle and lower lobectomy, and that it would be possible to extend the boundaries of safety for lung resection based on evaluation of cardio-pulmonary function by SPAO.