[Proximal ureter of the human in reflux nephropathy and in chronic, nonreflux-induced pyelonephritis....

The total area and the proportion of lumen, epithelium, submucosa and muscularis as well as connective tissue, musculature, and edema were determined by histologic and morphometric evaluation in cross sections of 30 segments of undilatated proximal ureter. The conditions in 8 reflux ureters from children were almost identical to those in 12 reflux ureters from adults. No statistically significant increase in proliferation of connective tissue within the submucosa and muscularis could be established. The primary difference between the reflux ureters and the 10 proximal ureters in reflux-unrelated chronic pyelonephritis was extensive inflammatory edema in the submucosa and muscularis in the latter. Pathophysiologic and pathogenetic aspects are discussed.