Simultaneous stapling of the lobar bronchus and pulmonary artery: is it actually dangerous?

We performed a left caudal lobectomy on a 3-month old male swine. During the lobectomy, the lobar bronchus and pulmonary artery were stapled simultaneously using an endostapler. According to a postmortem examination 42 days after the operation, the stumps were surrounded by granulation tissue with prominent accumulation of inflammatory cells. With respect to the bronchus, the stapled tissue remained as it was just after stapling, without degradation of the cartilage, smooth muscle or epithelial layers. In contrast, with respect to the pulmonary artery, the stapled tissue disappeared, which resulted in the formation of a new vascular stump with recruitment of a new adventitial layer and fibrotic tissue. Therefore, despite the simultaneous stapling, the vascular stump was separated from the bronchial stump. Our results suggest that the process of stump healing after stapling of the bronchus is different from that after stapling of the pulmonary artery: bronchial stump healing consists of extraluminal covering of the fibrotic tissues, while pulmonary arterial stump healing consists of intraluminal reformation of the intima and media. On the basis of the results, we believe that a bronchovascular fistula will not develop after simultaneous bronchovascular stapling unless the anterior wall of the bronchus has fallen away due to major stump necrosis.