An Experimental Study Of Mechanism About High Pressure Of Renal Pelvis Resulted To Hematuria

Objective:To study the relationship and mechanism between high pressure of renal pelvis and hematuria by establishing a miniature pig model of high pressure perfusion of renal pelvis.Methods:A total number of 40 kidneys of 20 male adult Guangxi Bama Miniature Pigs were divided into five groups(n=8) randomly and equally based on different perfusion pressure of renal pelvis:group A(0.00kPa), group B(6.67kPa), group C(13.33kPa), group D(20.00kPa) and group E(26.67kPa). Each group was perfused constantly in 45 minutes and urine was collected after perusing by every 5 minutes for total 9 times. It will be the end and kidney was dissected if severe hematuria was observed accompany with blood clots. After the experiment RBC in the urine were calculated by microscope and kidney tissues were stained by hematoxylin-eosin, Masson, Desmin and Aldehyde fuchsin(According to Gomiri). When and what and the severity of the hematuria appeared will be detected together with the morphology and histopathology of the kidney.Results:1.The relationship between high pressure perfusion of renal pelvis and hematuria:severity of the hematuria was different and microscopic hematuria was shown in all the groups. Hematuria was observed 3/8 at group C, 6/8 at group D,8/8 at group E, accompany with blood clots at group D were 1/8, at group E were 6/8(P<0.05) and the hematuria appeared took (10.00±5.00) min, (9.17±3.76) min, (6.25±2.31) min at group. C, group D, group E respectively.2. The relationship between high pressure perfusion of renal pelvis and RBC:the results suggested that the severity of hematuria at every group has no significant statistical differences before perfusion(P>0.05); the severity of hematuria at different time hematuria was observed between group A and group B has no significant statistical differences after perfusion(P>0.05) but it has significant statistical differences(P<0.05) around group A, C, D.3. Appearance of kidney after high pressure perfusion of renal pelvis:the color and morphology of kidneys at group A and group B has no differences, white spot and ecchymosis were appeared in some kidneys at group C and all kidneys at group D and group E by the time growth. It’s worth noting that laceration, hemorrhage and blood clots in the renal fornices were shown to some extent in some kidneys at group C and D and all kidneys at group E by the pressure perfusion increased.4. The changes of histopathology of kidney tissues after high pressure perfusion of renal pelvis:expansion of uriniferous tubules and congestion of the renal fornix could be observed at all group kidney tissues except group A. collective system transitional epithelium exfoliation were happened and more serious, laceration was shown in the renal fornix at group C, group D and group E, the occurrence rate of laceration at group C and group E has statistical difference (P<0.05). Interestingly, laceration happened only in the renal medulla area at group C while the laceration reached the renal cortex at group D for 1/8 and group E for 4/8.5. Normal renal fornix:renal fornix has two sides of renal minor calices and renal papillae and it looks like a "V", it can be seen that renal fornix and tissues around consist of collagen fibers and muscle fibers and elastic fibers but misdistribution by special staining, dedicates that it was the weakest part of the renal collecting system.Conclusions:High pressure perfusion of renal pelvis not only could cause uriniferous tubules expansion, kidney swelling, white spots and ecchymosises, but also lead to collective system injury and bleeding, by the perfusion pressure increased. When perfusion pressure of renal pelvis was 6.67 kPa or lower would not cause obvious hematuria. When perfusion pressure of renal pelvis was up to 13.33 kPa, macroscopic hematuria, collective system transitional epithelium exfoliation and renal fornix laceration would be appeared. When perfusion pressure of renal pelvis came to 20.00 kPa, it may induce severe laceration and bleeding. The incidence of renal fornix laceration and hematuria could reach 100% when to 26.67 kPa. The experimental results suggested:high pressure of renal pelvis could cause hematuria, and even lead to severe renal fornix laceration and bleeding. That were resulted to the physical structure characteristics and the content of kidney fibers and their distribution.