Influence of Hydronephrosis on GFR Among Patirents with Renal Injury

Objectives: To explore the influence of hydronephrosis on GFR quantificant in dynamic renal scans.Methods (1)From January 2015 to January 2017,the GFR of 183 patients who underwent both dynamic renal scans and dual sample methods(tGFR).patients were divided into normal[90ml(1.73m2·min)&#8804;tGFR<120ml(1.73m2·min)],mild[60ml(1.73m2·min)&#8804;tGFR<90ml(1.73m2·min)],moderate[30ml(1.73m2·min)&#8804;tGFR<60ml(1.73m2·min)] and severe[tGFR<30ml(1.73m2·min)]injury group based on their tGFR and DOQI.To determine the difference and correlation between Gates method(gGFR) and tGFR,the comparion was conducted with body surface area(BSA) normalization respectively.(2) From January 2015 to January 2017,the number of patients who underwent both dual sample methods(tGFR) and ultrasound study is 69.By comparing the tGFR and location and degree of hydronephrosis by ultrasound study,we could get the relationship between these three indicators.Results (1) In mild, moderate and severe renal injury group, the proportion of hydronephrosis are 8.2%, 21.18%, 43.57%.(2) In most cases, gGFR_BSA is higher than tGFR_BSA and the difference between tGFR_BSA and gGFR_BSA range from -72.34 to 25.8 ml / (1.73 m² • min). In the normal control group, gGFR_BSA is 94.28 ± 13.35 (1.73m2 • min) and tGFR_BSA is 97.36 ± 13.42 (1.73m2 • min), p> 0.05. In single hydronephrosis with renal injury, p <0.05; In mild or severe renal injury group of hydronephrosis of two kidneys, p> 0.05.(3) In mild, moderate and severe kidney injury groups, the correlation coefficients of single hydronephrosis between the two methods are 0.217 (p = 0.078), 0.517 (p <0.01), 0.218 (p = 0.399) and in groups of hydronephrosis of two kidneys ,the correlation coefficients are 0.135 (p = 0.800), 0.467 (p = 0.080), 0.397 (p = 0.436), respectively.(4) In the hydronephrosis group and the mild hydrocephalus group which are divided by ultrasound study, mild and moderate renal function injury cover 50%, while in the moderate hydrocephalus group, the renal function is normal, slightly decreased, moderately decreased, and severe decreased cover 4.54%, 31.81%, 59.09% and 4.43% respectively. In the severe hydronephrosis group, the renal function decreased slightly, decreased moderately, and decreased significantly, accounting for 34.29%, 54.29% and 11.43% respectively.Conclusion (1) As the degree of renal injury increases, the proportion of hydronephrosis gradually increased.(2) With regard to the location of the hydronephrosis, the Gates method’s value is limited, we should reference the quantitative results of the double plasma

Methods: No matter what degree of kidney damage occurs , we shouldn’t reference the result of Gates method alone, and we should combine with the double plasma method for a comprehensive analysis.(3) The correlation between Gates's method and the double plasma method is related to the location and degree of hydronephrosis. Single hydronephrosis is superior than the double hydronephrosis. The correlation coefficient of hydronephrosis associated with moderate renal injury is higher and associated with mild renal injury is lower. (4) With the degree of hydronephrosis increased, the renal function is worse. In a hospital where there is no conditional double-plasma method, GFR measured by the Gates method should be further judged based on the location and extent of hydronephrosis.Key words: Hydronephrosis; Renal dynamic imaging; Double plasma method; Gates method