Microradiographic demonstration of human intrarenal microlymphatic pathways.

Renal lymphatics play a prominent role in physiological and pathologic states. However, intrarenal microlymphatic morphology has not been well established in humans. We have developed microangiographic techniques for studying microlymphatic morphology. Lymphatics were identified by location, presence of valves, and histologic characteristics in 4 patients (3 presented here and 1 reported previously), all of whom had congestive cardiac states. The renal lymphatics begin in the cortical interstitium near glomeruli and run adjacent to afferent arterioles and interlobular arteries. They drain into arcuate and interlobar vessels and then into hilar lymphatics. They also originate in and drain the medullary structures in the area of the vasa recta. Our study details the microlymphatic morphology in humans and confirms the similarity of human lymphatics to those studied extensively in pigs and dogs.