Posterior pulmonary lobe: Segmental and vascular anatomy in human specimens

The posterior pulmonary lobe (PPL) is defined by an aberrant fissure runnin g horizontally on the costal surface of the lower lobe. We studied the freq uency of the PPL, and the ramification of bronchi and vessels in the PPL, a nd so describe mainly these differences compared to the normal lung. Ninete en PPL cases (15 right and 3 left) were found in 273 (116 right and 157 lef t) human lung specimens. The incidence of PPL was 13% on the right side and 3% on the left side. The PPL frequently (right 87%, left 50%) corresponded to S-6(superior segment). Analysis of the ramification of bronchi revealed that B-7 (medial basal bronchus) tended to form a common trunk; with B* (s ubsuperior bronchus) or B-8 (anterior basal bronchus). Analysis of the rami fication of veins revealed that V-6 (superior vein) tributaries were often double, and V-6 tended to disperse widely. Anomalies in which the segmental artery and vein communicated with other segments were found in seven cases (37%) (3 arteries and 3 veins, 6 right and 1 left) in PPL. These results s how that the PPL does not always correspond to S-6 and frequently has an an omalous vessel from other segments. This is valuable surgical information, particularly in S-6 segmentectomy. (C) 2000 Wiley-Liss, Inc.