Ten infants under 6 months old underwent surgery for obstruction of the ureteropelvic junction. Craniocaudal light microscopy showed subdivision of the resected ureteropelvic junction into three portions: prestenotic, stenotic, and poststenotic. The prestenotic portion was characterized by dilatation of the ureteral lumen, flattening of its mucosal folds and thinning of the urothelium; the stenotic tract showed partial or total loss of the epithelium and fibrosis of the mucosal and fibromuscular coats. No modifications were detected in the poststenotic portion. We advance the hypothesis that a primary epithelial break might cause urine to spread inside the ureteral wall and consequently the mastocytes to migrate and degranulate within the mucosal and fibromuscular coasts. The histamine and prostaglandins produced by the mastocytes could induce prolonged muscular spasm, in turn responsible for increasing the intrapelvic pressure and so causing enlargement of the epithelial break. A connective tissue reaction of the ureteral wall would thus occur, which should be considered a secondary event leading to fibrotic stenosis of the ureteropelvic junction.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Clark WR, Malek RS (1987) Ureteropelvic junction obstruction. Observation on the classic type in adults. J Urol 138: 276
Dell'Agnola CA, Carmassi L, Tadini B, Ghisoni L, Carmignani L (1992) Predictability of duration and severity of congenital hydronephrosis as a cause of smooth muscle deterioration in pyelo-ureteral junction obstruction. Eur J Pediatr Surg 2:274
Djurnuus JC, Constantinou CE (1982) Chronic ureteric obstruction and its impact on the coordinating mechanisms of peristalsis (pyeloureteric pacemaker system). Urol Res 10:267
Faussone Pellegrini MS, Rizzo M (1982) Some ultrastructural aspects of human pathological pelvi-ureteric junction in idiopathic hydronephrosis. J Submicrosc Cytol Pathol 14:697
Fussel FN, Roberts JA (1978) Chronic pyelonephritis. Electron microscopic study. III. The ureter. Invest Urol 17:108
Gosling JA, Dixon JS (1978) Functional obstruction of ureter and renal pelvis. A histological and electron microscopic study. Br J Urol 50:145
Hanna MK, Jeffs RD, Sturgess JM, Barkin M (1976) Ureteral structure and ultrastructure. Part II. Congenital uretero-pelvic junction obstruction and primary obstructive megaureter. J Urol 116:725
Hicks RM (1965) The fine structure of the transitional epithelium of rat ureter. J Cell Biol 26:25
Hinman F Jr (1970) The pathophysiology of urinary obstruction. In: Campell MF, Harrison JH (eds) Urology, 3rd edn. Saunders, Philadelphia, p 313
Hinman F Jr, Oppenheimer RO, Katz IL (1983) Accelerated obstruction at the ureteropelvic junction in adults. J Urol 129:812
Hollowell JG, Altman HG, Snyder H McC, Duckett JW (1989) Coexisting ureteropelvic junction obstruction and vesicoureteral reflux: diagnostic and therapeutic implications. J Urol 142:490
Notley RG (1968) Electron microscopy of the upper ureter and the pelvic-ureteric junction. Br J Urol 40:37
Notley RG (1970) The musculature of the human ureter. Br J Urol 42:724
Peters CA, Mandell J, Lebowitz RL, Colodny AH, Bauer SB, Hendren WH, Retik AB (1989) Congenital obstructed megaureters in early infancy: diagnosis and treatment. J Urol 142:641
Richardson IW, Neergaard EB (1972) The physics of fluids in rigid and elastic vessels. In: Physics for biology and medicine. Wiley, London, p 38
Ugaily-Thulesius L, Thulesius O (1988) The effects of urine on mastcells and smooth muscle of the human ureter. Urol Res 16:441
Ugaily-Thulcsius L, Thulesius O, Sabha M (1988) The effect of urothelial damage on ureteral motility, an ultrastructural and functional study. Brit J Urol 62:19
Walton J, Yoshiyama JM, Vanderlaan M (1982) Ultrastructure of the rat urothelium in en face section. J Submicrosc Cytol Pathol 14:1
About this article
Cite this article
Bartoli, F.A., Paradies, G., Leggio, A. et al. Urothelium damage as the primary cause of ureteropelvic junction obstruction: a new hypothesis. Urol. Res. 24, 9–13 (1996). https://doi.org/10.1007/BF00296726
- Ureteropelvic junction obstruction