Variations of pulmonary vessels: some practical implications for lung resections.

Anatomical variations of the bronchi and lung vessels may be important obstacles during lung resection if overlooked. We designed this study to determine the frequency and types of variations of lung vessels during lung resections. In a 3[1/2]-year-period, anatomical variations were recorded and registered by digital photography at the hilar and/or interlobar areas during lung resection surgery on 140 patients. Variations of the pulmonary blood vessels were observed in 23 patients. Of these, 12 patients had variations of the middle lobe vessels. Middle lobe veins emptying into the right inferior pulmonary vein, and middle lobe arteries originating from the artery for the basal segments, were observed in four patients each; two separate middle lobe arteries and a low origin of the middle lobe artery existed in three and one patient, respectively. Among seven patients with variations of the lingular vessels, the lingular artery originating from the artery for the basal segments was found in three patients; the remaining variations referred to absent or low origin of the lingular artery (in one patient each), and to an aberrant lingular vein, separate from the upper lobe vein (two patients). A single unilateral pulmonary vein and a left-sided bronchial tree completely behind the pulmonary artery existed in three and one patient, respectively. Potential problems related to these variations during resectional lung surgery are discussed. Awareness of the most frequent variations is of utmost importance for safe lung resections.