Histopathological characteristics of different parts of surgical specimens of UPJ stenosis

Objective To observe the pathological changes of different anatomical sites in the specimens obtained from ureteropelvic junction obstruction (UPJO) caused by UPJ stenosis. Materials and Methods A total of 34 cases of UPJO were performed. The lesion of the ureteropelvic junction was visualized as the center, the 1.5cm renal pelvis segment was taken along the upper edge of the lesion segment (as the control group). Along the lower edge of the ureteral stricture, 1cm of ureteral stricture tissue was taken downward. Different dyeing methods were used to observe the tissue arrangement of different parts, the ratio of muscle to fiber tissue and the distribution of interstitial cells of Cajal(ICC) . Results The number of ICCs in the lesion segment was reduced or even absent, disordered arrangement of muscle tissue was seen, the fibrous tissue proliferated to varying degrees. The pathological changes were statistically different from those of normal segment and ureteral stricture segment. Conclusion The decrease of ICCs cells and the degree of tissue fibrosis are closely related to the pathogenesis and disease progression of UPJO caused by UPJ stenosis.