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.

Can pyeloplasty restore normal renal function in patients with severe unilateral ureteropelvic junction obstruction and DRF < 35

PURPOSE

To assess the outcome of successful pyeloplasty in infants with Ureteropelvic Junction Obstruction (UPJO) and a differential renal function of (DRF) < 35% whether they can attain normal postoperative renal function or not.

METHODS

All children who were diagnosed with antenatal hydronephrosis due to UPJO were presented to our institutions and were prospectively followed up. Pyeloplasty was performed based on predefined indications such as: initial DRF ≤40%, progression of hydronephrosis, and febrile urinary tract infection (UTI). A total of 173 children, who had successful surgical intervention due to impaired DFR, were divided according to their pre-intervention DRF value as follows: DRF <35% (group I) and DRF 35-40% (group II). The renal morphology and function changes were recorded and used for comparison between both groups.

RESULTS

Group I was comprised of 79 patients, and group II included 94 patients. Pyeloplasty achieved significant improvement in the anatomical and functional indices in both groups (p-value <0.001). The degree of improvement in Anteroposterior diameter (APD) and cortical thickness was comparable in both groups (P-value, 0.64 and 0.44 respectively). While the improvement in the DRF was significantly higher in group I (16.06 ± 6.6) than in group II (6.25 ± 2.66) (P-value <0.001). Despite that, a significantly higher percentage of infants in group II (61.7%) achieved normal final DRF compared with only (10.1%) in group I (Figure).

CONCLUSION

Even in severely impaired renal function (<35%), successful pyeloplasty can recover a significant part of lost renal function. However, most of these patients do not achieve normal postoperative renal function.

Functional outcome after neonatal pyeloplasty in antenatally diagnosed uretero-pelvic junction obstruction

Background

With routine antenatal ultrasonography, fetal hydronephrosis is commonly diagnosed. This leads to early detection of postnatal uretero-pelvic junction obstruction which may require surgical intervention. But, there is no clear consensus in the benefits of operating these patients in the neonatal age.

Methods

Aim—To study the functional outcome after pyeloplasty in neonates with antenatally diagnosed unilateral uretero-pelvic junction obstruction (UPJO). Records of all neonates (N = 48) who presented between 2016 and 2018 with prenatal diagnosis of unilateral UPJO and underwent a Anderson-Hyne’s Pyeloplasty were retrospectively analyzed. Indications for surgery were SFU grade 3 or 4, a split renal function (SRF) < 40% on a diuretic renal scan and antero-posterior renal pelvic diameter (APD) > 2.5 cm with parenchymal thinning. Parenchymal thickness (PT) and APD measured by ultrasonography, and SRF measured by 99 m Tc-EC renal scan were compared before and after surgery.

Results

Our study comprised of 48 patients with 79.2% males (n = 38). UPJO affected the left side more (n = 30, 62.5%). The mean age at pyeloplasty was 28 days (range 26–30). The outcome was considered successful in 46 (95.84%) patients. The APD decreased from a mean of 3.5 cm APD preoperatively to 1.38 cm 1 year later which was statistically significant (p < 0.001). The PT increased from 3.95 to 7.1 mm 1 year postoperatively which was significant (p < 0.001). The drainage pattern and SRF improved in 46 (95.84%) patients. The SRF improved from a mean of 35.48–44.7% 1 year postoperatively which was significant (p < 0.001).

Conclusion

Pyeloplasty done in the neonatal age for prenatally diagnosed UPJO, having SFU grade 3–4 UPJO, leads to significant improvement of SRF and PT with minimal complications. Neonatal Pyeloplasty for significant UPJO is a safe procedure which provides the kidney maximum opportunity to improve function.

Early pyeloplasty versus conservative management of severe ureteropelvic junction obstruction in asymptomatic infants

BACKGROUND

Ureteric-pelvic junction obstruction (UPJO) is the most common cause of antenatal and neonatal hydronephrosis and its management remains controversial. While conservative management is advocated for all, this strategy puts a quarter of these patients at risk for possibly irreversible renal damage.

AIM

In this study, we compare functional and anatomic outcomes in newborns and infants less than 1 year of age with high-grade unilateral UPJO, following early surgical pyeloplasty (ESP) versus conservative management (CM).

MATERIALS AND METHODS

This was a single center prospective interventional study. Infants referred to our tertiary care pediatric surgery clinic between September 2016 and September 2018 with UPJO were considered. To be included patients must have been less than 1 year old, lack of clinical symptoms, suffer from severe hydronephrosis as defined by Society for Fetal Urology (SFU) grades 3 or 4, and have affected kidney Split Renal Function (SRF) above 40%. Patients with bilateral disease, structural anomalies, or an abnormal voiding cystourethrogram (VCUG) were excluded. Anatomical and functional outcomes were measured and compared at 6 and 12 months.

RESULTS

Fifty-six patients were assigned to receive either ESP (n = 28) or CM (n = 28). At 6 months Cortical thickness, polar length, and SFU indices were significantly lower in the ESP group, while none of the outcomes were significantly different between the two groups at 12 months. Despite the two groups not being different at 12 months regarding differential renal function (DRF), there was a significant decrease of function in the CM group compared to baseline.

CONCLUSION

When considering treatment options for infants with high-grade UPJO, it appears that ESP hastens improvement of anatomic and functional indices, while CM may lead to a significant deterioration in renal function.

Matrix Remodeling-Associated Protein 5 in Urinary Exosomes as a Potential Novel Marker of Obstructive Nephropathy in Children With Ureteropelvic Junction Obstruction

Recent investigations have described the use of urinary matrix remodeling-associated protein 5 (MXRA5) as a novel biomarker of kidney impairment in the setting of chronic kidney disease. In this study, we aimed to evaluate the possible clinical application of urinary MXRA5 as a useful non-invasive marker in the urine from the affected renal pelvis and bladder of children with ureteropelvic junction obstruction (UPJO). We conducted a prospective cohort study of patients aged <12 months with prenatally diagnosed unilateral UPJO who underwent dismembered pyeloplasty in 2018 or 2019, and a sex- and age-matched control group of healthy children. Blood urea nitrogen and creatinine levels were normal in all the patients. The whole urine and urinary exosomal concentrations of MXRA5 were measured by enzyme-linked immunosorbent assay. The correlations between bladder/renal pelvic MXRA5 levels and differential renal function (DRF) in the affected kidney were also determined. A total of 35 UPJO patients and 12 controls were enrolled in the study. There was no significant difference in whole-urine MXRA5 level between the controls and UPJO patients. However, the exosomal MXRA5 level was significantly lower in the controls than in patients with UPJO (p < 0.05). There were non-significant correlations between bladder and renal pelvis whole-urine MXRA5 levels and DRF (R ² = 0.1115, p = 0.05 and R ² = 0.3313, p = 0.0502, respectively). The strongest correlation was between exosomal MXRA5 level in the renal pelvis and DRF (R ² = 0.8128, p < 0.0001). Urinary exosomal MXRA5 level was significantly higher in children with UPJO than controls. Higher urinary exosomal MXRA5 levels were significantly correlated with lower DRF in the affected kidney in children with UPJO.

Predictive Factors of Contralateral Operation after Initial Pyeloplasty in Children with Antenatally Detected Bilateral Hydronephrosis Due to Ureteropelvic Junction Obstruction

OBJECTIVES

This study was performed to analyze the predictive factors of a contralateral operation after initial pyeloplasty in patients with antenatally detected bilateral ureteropelvic junction obstruction.

METHODS

Patients with prenatally diagnosed bilateral ureteropelvic junction obstruction who underwent initial pyeloplasty (aged <12 months at initial pyeloplasty) were offered to participate in the study. Patients were recruited from January 2012 to December 2015. The anteroposterior renal pelvic diameter, parenchymal thickness, and calyceal dilatation were evaluated. Predictive factors of contralateral pyeloplasty after initial unilateral pyeloplasty were also examined.

RESULTS

In total, 82 patients were included in the study (mean age, 2.8 months). Among all patients who underwent initial pyeloplasty, additional contralateral pyeloplasty was required in 11 patients (13.4%). The outcome of contralateral hydronephrosis was assessed as resolution, persistence, or surgery. The median anteroposterior renal pelvic diameter and calyceal dilatation were significantly different among the groups (p < 0.001). Calyceal dilatation of ≥10 mm and a calyceal dilatation/parenchymal thickness ratio of ≥5 strongly suggested the likelihood of a contralateral operation.

CONCLUSIONS

In most patients with bilateral ureteropelvic junction obstruction, improvement or resolution of contralateral hydronephrosis following initial unilateral pyeloplasty can be expected. Patients with contralateral calyceal dilatation >10 mm and the calyceal dilatation/parenchymal thickness ratio >5 are at higher risk of surgery.

Functional Results of Laparoscopic Pyeloplasty in Children: Single Institute Experience in Long Term

OBJECTIVE

The aim of this study was to evaluate the long-term functional outcomes of laparoscopic pyeloplasty (LP) in children for consecutive cases of single institute.

MATERIALS AND METHODS

Our laparoscopy database was investigated for children in terms of LP between June 2008 and April 2015. All the patients had ureteropelvic junction obstruction (UPJO) and LP was performed. Demographic data including age, gender, side of UPJO, operation time, estimated blood loss (EBL), hospital stay and complications according to Clavien classifications were recorded. Renal ultrasonography and diethylenetriamine penta-acetate (DTPA) scintigraphies were respectively performed 3, 12 and 24 months after surgery. Statistical analyses were performed and p value was accepted as significant at <0.05.

RESULT

Mean follow-up was 34 ± 4.7 months. The mean age was 13 (6-72) months. A total of 153 (110 boys and 43 girls) LP patients enrolled. Of that, 93 (60.78%) LP were in left side and 60 (39.21%) were in right side. Three cases needed open conversation according to difficulties in anastomosis. Aberrant crossing vessel was observed in 12 (7.84%) patients. The mean operation time was 155 ± 21 min and the mean EBL was 22 ± 11.1 ml. The mean hospital stay was 3.4 days. Anastomotic leakage was the common complication (in 13 patients) that was successfully managed conservatively (Clavien 1). Eight patients experienced unsuccessful LP and underwent open pyeloplasty (Clavien 3b). The mean split renal function significantly increased in DTPA scintigraphy in follow-up. The overall success was 91%.

CONCLUSIONS

The LP procedure can be an effective and safe surgical method for childhood UPJO, specifically in the experienced hands of pioneer centers.