Bronchopulmonary Segmentation in Humans and Dogs: A Comparative Narrative Review Highlighting Anatomical Gaps and Surgical Implications.

Bronchopulmonary segmentation (BS) is an anatomical concept, poorly described in veterinary medicine, and involve a specific segmental bronchus, a corresponding segmental artery, segmental veins draining into intersegmental veins, and intersegmental septa. While pioneer studies were comparative in humans and domestic animals, this research path diverged decades ago, and the field has since lacked a proper, functional categorization of canine lungs into bronchial segments. Veterinary anatomical nomenclature does recognize this segmentation, but the classification is traditionally based on tertiary (or segmental) bronchi and does not specify how many segments each pulmonary lobe may have. A comparative analysis of the scarce literature suggests that the canine species possesses the necessary anatomical requirements for this classification. These include a segmental bronchus, a corresponding segmental artery, segmental veins draining into intersegmental veins, and intersegmental septa containing connective tissue. Further studies are needed to better detail the variation in pulmonary structures, particularly the venous drainage that defines BS. Specific anatomical ratios and relations should also be described in relation to a dog's size, breed, and sex. Although segmentectomy has seemed distant for veterinary medicine, these findings and future studies may bring its use closer to a reality, similar to its established role in medicine.