BOB Ped Surg 2023 - Maria Jose Rosell Echevarria, IBEROAMERICANA - Presentation

Hello everyone, my name is Maria José Rossel from Nuestra Señora de Candelaria University Hospital in Santa Cruz de Tenerife, Spain. First of all, thanks for the opportunity for me to being here at the Best of the Best in Pediatric Surgery 2023, presenting our research about the use of urinary osmolality to assess renal function before and after surgery on patients with ureteropelvic junction obstruction, presented at the Ibero American Congress 2022. Ureteropelvic junction obstruction, UPJO is a malformation of the urinary tract characterized by mechanical restriction of the physiological flow of urine from the renal pelvis to the ureter. A persistent obstruction to the urinary flow can induce physiopathological changes on the pelvis and renal parenchyma secondary to hydrostatic hyperpressure of the urinary tract. According to our guidelines, the preferred functional parameter of pediatric urologist in the evaluation of UPJO is the split renal function in a renogram. However, this percentage does not reflect renal function. Our goal is to determine the usefulness of basic renal function markers to assess renal function in children with UPJO and to know the most sensitive marker of renal damage in those patients. We conducted a retrospective review of the basic renal function parameters collected in three different stages. The first stage or the moment of diagnosis, the second stage after surgical integration, and the third or final stage on the end of the follow-up. We have 71 patients with diagnosis of unilateral UPJO underwent surgical integration in our hospital between 1980 and 2021. In our study, we focus on these basic renal function markers, the maximum urinary osmolality, we show us the renal concentrating capacity. The albumin creatinine ratio that shown a failure of glomerular membrane selective permeability. The NAC creatinine ratio whose increasing levels means that a proximal tubule damage exists. The glomerular filtration rate and the serum creatinine levels. When evaluating the entire qualitative data results, we did find that the maximum urinary osmolality, which is dependent of the hyperpressure was altered in 64% of the patients at the moment of diagnosis. After that, this value decreases to 53% after surgery and drops to 14% at the end of the follow-up. The albumin creatinine ratio keeps a maintaining value throughout the study. Compared to the GFR and serum creatinine percentage, the osmolality continues to be the most altered parameter. We also found that the percentage of abnormal renal split function in renogram was lower than the alteration of renal concentrating capacity at the first and second stage of the study. So when comparing renogram split function versus renal concentrating capacity, the maximum urinary osmolality remains to be the most altered parameter. At the moment of diagnosis, we found a statistically significant direct correlation between maximum urinary osmolality and healthy kidney longitudinal diameter. On the contrary, an inverse correlation were found between maximum urinary osmolality and albumin creatinine and NAC creatinine ratio. We did find too a significant direct correlation between the maximum urinary osmolality at diagnosis and after surgery. On the other hand, we found a significant inverse correlation between maximum urinary osmolality and the NAC creatinine ratio during post-operative period. In our series, when we review our quantitative data result, we did find a significant increase in the maximum urinary osmolality and the serum creatinine values. On the contrary, we found a significant decrease in the albumin creatinine ratio along the study. Maximum urinary osmolality is the parameter with higher sensitivity and negative predictive value for detection of impaired renal function in UPJO. The use of these parameters avoids the inconvenience of the technique for diuretic renogram in the pediatric population. Thank you so much for listening. I leave the contact information here for any consultation. Thank you.