An autopsy study of the structure of the small vessels in biopsies from the lingula and upper and lower lobes: implications for vascular assessment.

We examined the structure of the muscular pulmonary arteries in the three lung sites most often used for lung biopsy. In a subset of cases, we also examined tissue from the central portion of the lower lobe. In each vessel we measured the area of intima and muscle media and expressed these data as a percentage of the total tissue area; vessel size was standardized by using the length of the internal elastic lamina. We found that no one biopsy site best represented the arterial structure of the central aspect of the lower lobe. The lingula had greater numbers of arteries which met the criteria for assessment from than did the other biopsy sites. The vessel structure was similar between the lingula and peripheral aspect of the upper lobe, but the lingula had a slightly increased area of muscle media and decreased intima when compared with the superior segment of the lower lobe. This was not a function of vessel size, since the overall cumulative distribution curve of percent muscle divided by length of internal elastic lamina was also shifted between lingula and lower lobe. We conclude that, in the assessment of arterial vascular structure, any of the standardly used biopsy sites can be representative of the lung. Although there may be differences in structure between the sites in individual patients depending on concurrent disease in any of the sites, there is no consistent site effect on vessel structure. If a formal morphometric evaluation of arterial structure is required, the lingula appears to have more vessels which fit the criteria for assessment.