How Does the Presence of Antenatally Detected Caliectasis Predict the Risk of Postnatal Surgical Intervention?

Outcome analysis of immediate and delayed laparoscopic pyeloplasty in infants with severe ureteropelvic junction obstruction

OBJECTIVE

The treatment timing of ureteropelvic junction obstruction (UPJO) in infants remains controversial. This study aimed to compare the recovery effect of renal morphology of immediate and delayed laparoscopic pyeloplasty in infants with severe UPJO.

METHODS

The infants with severe UPJO-induced hydronephrosis who underwent laparoscopic pyeloplasty according to their age at the time of surgery [the immediate treatment (IT) group: ≤1 month of birth, the delayed treatment (LT) group: 3-6 months of birth] in our center between 2010 and 2019 were enrolled in this study. Ultrasonography was used to assess renal morphology, including anteroposterior diameter (APD) of a pelvic, parenchymal thickness (PT), polar length (PL), and Society of Fetal Urology (SFU) grade. Preoperative and postoperative renal morphological outcomes at 6, 12, and 24 months were measured and compared.

RESULTS

During this period, a total of 135 patients were assigned to receive either IT (n = 73) or LT (n = 62) and were included for analysis. There were no significant differences in renal morphology indices at baseline between groups of IT and LT. The APD, PT, and PL in both groups all recovered to certain degrees compared with those at baseline, however, the IT group recovered more significantly than the LT group. Despite there being no significant difference in SFU grade between the two groups before and after surgery, the reduction of SFU grade in the IT group was more significant than that in the LT group during the 6-, 12- and 24-month follow-up periods. The PL, SFU, and APD were greater in the IT group than in the LT group at 6, 12, and 24 months of follow-up. At 6 months PL was not significantly higher between the two groups, while the outcome was significantly different at 12 months and 24 months.

CONCLUSION

Immediate laparoscopic pyeloplasty for the infant with severe ureteropelvic junction obstruction is effective, and it can accelerate the recovery of renal morphological indices in infants with severe UPJO-induced hydronephrosis.

Urinary Ultrasound and Other Imaging for Ureteropelvic Junction Type Hydronephrosis (UPJHN)

Ultrasound is the main imaging study used to diagnose ureteropelvic junction (UPJ) obstruction. On ultrasound, abnormal dilatation of the pelvicalyceal system of varying degrees is seen, whereas the ureter is normal in caliber. A properly performed study provides essential information regarding laterality, renal size, thickness, and architecture of the renal cortex and degree of dilatation of the pelvicalyceal system. Doppler ultrasound may identify a crossing vessel, when present. This imaging method also has been used differentiating obstructive from non-obstructive hydronephrosis by renal arterial resistive index measurements. Abdominal radiographs may show soft tissue fullness, bulging of the flank, and displacement of bowel loops from the affected side. The voiding/micturating cystourethrogram helps exclude other causes of upper tract dilatation, including vesicoureteral reflux, urethral valves, and ureteroceles. Computerized Tomography angiography with multiplanar reformation and three-dimensional images may be used to depict suspected crossing vessels as a cause of UPJ obstruction in older children and adults. Magnetic Resonance Urography has progressed significantly in recent years due to the development of both hardware and software that are used to generate high-resolution images. This imaging technique currently allows for the detailed assessment of urinary tract anatomy, while also providing information regarding renal function, including differential renal function, and the presence or absence of obstructive uropathy.

Safe discharge parameters for patients with isolated antenatal hydronephrosis

INTRODUCTION

Antenatal hydronephrosis is a steady source of urology referrals since the era of routine fetal ultrasonography. Although most resolve, there are no guidelines for follow-up.

OBJECTIVE

Our goal is to define safe parameters with which patients can be discharged early and avoid unnecessary follow-up.

METHODS

We retrospectively reviewed all patients referred to a single children's referral hospital center for isolated antenetal hydronephrosis between 2010 and 2012. We looked at patients and renal units separately and divided the cohort into two groups for comparison. Our analysis endpoint is progression. That is, if the initial postnatal anterior-posterior diameter (APD) is less than 10 mm, progression occurs if the APD increases to 10 mm or above upon follow-up. Conversely, if the initial APD is 10 mm or more in at least one renal unit, progression occurs if the APD remains at 10 mm or above upon follow-up.

RESULTS

There majority of the 186 patients and 308 renal units included in the analysis, were classified in the APD less than 10 mm group. Most renal units in the APD of less than 10 mm group were of SFU grades 0-2 (92.1%) and most of the renal units in the APD of 10 mm or greater group were of SFU grades 3-4 (60%) (Table). Only 19 renal units (6.2%) underwent pyeloplasty, and they were all from the APD of 10 mm or greater group and classified as SFU grade 3-4. No renal unit with an APD of less than 10 mm, nor any with an APD of 10 mm or greater and a SFU grade 0-2 underwent pyeloplasty. More than half of the renal units' hydronephrosis resolved in the APD of 10 mm or greater group, in comparison with 96.1% of the APD of less than 10 mm group. On multivariate analysis, patients with an APD of 10 mm or greater were 7.76 times more likely to show progression (p = 0.0006).

CONCLUSION

An initial postnatal APD of 10 mm or greater, with a SFU grade 3-4, merits follow-up. However, all patients with an APD of less than 10 mm, especially when with a SFU grade 1-2, can be safely discharged as they are unlikely to experience complications.

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.

A New Grading System for the Management of Antenatal Hydronephrosis

BACKGROUND AND OBJECTIVES

Standard clinical assessments do not predict surgical intervention in patients with a moderate degree of upper tract hydronephrosis. This study investigated whether combined measures of renal calyceal dilation and anteroposterior diameter (APD) of the renal pelvis at the first postnatal ultrasound better predict surgical intervention beyond standard assessments of the APD or Society of Fetal Urology (SFU) grading system.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective cohort of 348 children with antenatal hydronephrosis followed from 2003 to 2013 were studied. Using Cox regression, the risk for surgery by APD, SFU, and combined grading on the basis of the first postnatal ultrasound was calculated. The predictive capability of each grading system for surgery was determined by calculating the positive likelihood ratio (LR+).

RESULTS

The combination of APD≥6-9 mm and diffuse caliectasis had a hazard ratio (HR) of 19.5 (95% confidence interval [95% CI], 3.94 to 96.9) versus 0.59 (95% CI, 0.05 to 6.53) for APD≥6-9 mm alone and a similar risk of 8.9 for SFU grade 3 (95% CI, 3.84 to 20.9). The combination of APD≥9-15 mm and diffuse caliectasis had an HR of 18.7 (95% CI, 4.36 to 80.4) versus 1.75 (95% CI, 0.29 to 10.5) for APD≥9-15 mm alone. The LR+ for surgery for diffuse caliectasis and APD≥6-9 mm was higher than for APD≥6-9 mm alone (HR=2.62; 95% CI, 0.87 to 7.94 versus HR=0.04; 95% CI, 0.01 to 0.32) and was higher for APD≥9-15 mm and diffuse caliectasis than APD≥9-15 mm alone (HR=2.0; 95% CI, 1.15 to 3.45 versus HR=0.14; 95% CI, 0.04 to 0.43). Both combined groups of moderate hydronephrosis (APD≥6-9 mm or ≥9-15 mm with diffuse caliectasis) had only slightly higher LR+ than SFU grade 3 (HR=1.89; 95% CI, 1.17 to 3.05).

CONCLUSIONS

These results suggest a grading system combining APD and diffuse caliectasis distinguishes those children with moderate degrees of upper tract hydronephrosis that are at higher risk of surgery.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.