Factors predicting improvement of differential renal function after pyeloplasty in children of ureteropelvic junction obstruction

Is cortical transit time a parameter to prove relief of obstruction after pyeloplasty in antenatally diagnosed ureteropelvic junction obstruction

PURPOSE

The study aims to determine the possible improvement in cortical transit time (CTT) after surgery in infants with antenatally diagnosed ureteropelvic junction obstruction (UPJO), and investigate the correlation of CTT with preoperative renal function and parenchymal thickness.

PATIENTS AND METHODS

Medical charts of 32 antenatally diagnosed children with UPJO operated on between 2014 and 2021 were reviewed. Patients' demographics, preoperative and postoperative anteroposterior diameter (APD), parenchymal thickness (PT) ratio, differential renal function (DF), drainage patterns and CTT were compared to determine operative benefit. Preoperative CTT of each patient was also grouped as severely delayed (> 6 min) and moderately delayed (3-5 min) and compared. The correlation between the preoperative CTT and preoperative DF and PT ratio was investigated.

RESULTS

The median age of the patients was 8.8 months (1-24 months). The CTT (mean: 6.8 ± 3.0 min) was prolonged before surgery and was significantly improved (mean 4.6 ± 1.0 min) after the operation (p < 0.001). A significant negative correlation was detected between the CTT and preoperative DF and between the CTT and preoperative PT ratio. Preoperative DF was found significantly impaired in patients within the severely prolonged CTT group compared to those within the moderately prolonged CTT group. Significant improvement in DF was detected in patients in the severely prolonged CTT group after surgery.

CONCLUSION

CTT is a parameter to prove relief of obstruction in patients with antenatally diagnosed UPJO after surgery. CTT is negatively correlated with preoperative DF and PT ratio. Severely prolonged CTT may be considered to be an indication of early surgical intervention.

Analysis of risk factors for stenosis after laparoscopic pyeloplasty in the treatment of ureteropelvic junction obstruction

BACKGROUND

Laparoscopic ureteroplasty is an effective method for managing ureteropelvic junction obstruction. Despite its high success rate, there remains a subset of patients who do not experience improvement in the hydrops.

METHODS

The study retrospectively analyzed the data of 143 patients with ureteropelvic junction obstruction (UPJO) who underwent laparoscopic pyeloplasty (LP) in our hospital from January 2015 to May 2022. Logistic regression was used to analyze the risk factors of recurrence stenosis after UPJO.

RESULTS

Out of these patients, 119 had complete clinical data and follow-up records. Among these patients, restenosis occurred in nine cases after the operation. There was a significant statistical difference in blood loss (P < 0.05). Univariate and multivariate logistic regression analysis revealed that the preoperative separation degree of the renal pelvis, cystatin C, and intraoperative blood loss were potential risk factors for recurrent stenosis after primary LP. When divided by split renal function (SRF), the odds ratio (OR) was 7.850 (P = 0.044), indicating that it was an independent risk factor for postoperative restenosis. Similarly, the OR for stenotic segment length was 0.025 (P = 0.011), also indicating it as an independent risk factor for restenosis. The areas under the receiver operating characteristic curve for stenotic segment length and SRF were 0.9056 and 0.7697, respectively.

CONCLUSION

In our study, we identified that preoperative renal pelvis separation, cystatin C, and intraoperative blood loss were potential risk factors for postoperative restenosis. SRF and stenosis segment length were independent risk factors for postoperative restenosis.

Association between NDUFS1 from urinary extracellular vesicles and decreased differential renal function in children with ureteropelvic junction obstruction

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is the most common cause of pediatric congenital hydronephrosis, and continuous kidney function monitoring plays a role in guiding the treatment of UPJO. In this study, we aimed to explore the differentially expressed proteins (DEPs) in the urinary extracellular vesicles(uEVs) of children with UPJO and determine potential biomarkers of uEVs proteins that reflect kidney function changes.

METHODS

Preoperative urine samples from 6 unilateral UPJO patients were collected and divided into two groups: differential renal function (DRF) ≥ 40% and DRF < 40%.We subsequently used data-independent acquisition (DIA) to identify and quantify uEVs proteins in urine, screened for DEPs between the two groups, and analyzed biofunctional enrichment information. The proteomic data were evaluated by Western blotting and enzyme-linked immunosorbent assay (ELISA) in a new UPJO testing cohort.

RESULTS

After one-way ANOVA, a P adj value < 0.05 (P-value corrected by Benjamin-Hochberg) was taken, and the absolute value of the difference multiple was more than 1.5 as the screening basis for obtaining 334 DEPs. After analyzing the enrichment of the DEPs according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment combined with the protein-protein interaction (PPI) network results, we selected nicotinamide adenine dinucleotide-ubiquinone oxidoreductase core subunit S1 (NDUFS1) for further detection. The expression of NDUFS1 in uEVs was significantly lower in patients with DRF < 40% (1.182 ± 0.437 vs. 1.818 ± 0.489, P < 0.05), and the expression level of NDUFS1 was correlated with the DRF in the affected kidney (r = 0.78, P < 0.05). However, the NDUFS1 concentration in intravesical urine was not necessarily related to the change in DRF (r = 0.28, P = 0.24).

CONCLUSIONS

Reduced expression of NDUFS1 in uEVs might indicate the decline of DRF in children with UPJO.