Results of a practical protocol for management of prenatally detected hydronephrosis due to ureteropelvic junction obstruction.

INTRODUCTION: Several algorithms exist for the management of prenatally diagnosed hydronephrosis due to ureteropelvic junction obstruction (UPJO). We utilize a conservative and practical approach emphasizing observation, with less frequent use of renal flow scans (RFS). We reviewed the results of 143 pediatric patients with congenital UPJO managed at our institution, focusing on surveillance and selective utilization of RFS, according to a standardized protocol.
MATERIALS AND METHODS: Charts of all infants with prenatally detected UPJO treated surgically or followed conservatively according to our protocol were reviewed. Patients were initially evaluated with ultrasound (US), voiding cystourethrogram, and RFS. Successive follow-up was with interval US. RFS was reserved for those with worsening hydronephrosis or that which failed to improve on US by 1 year. Radiographic studies and operative reports were examined. Gender, side of UPJO, degree of hydronephrosis, mode of management, and current status of the patients were noted.
RESULTS: The records of 143 patients and a total of 198 renal units (RU) were reviewed. The male:female ratio was 2.7. UPJO was unilateral in 88 (61%) patients and occurred more frequently on the left side (68%). Obstruction was bilateral in 55 (39%) patients. Initial US grade of hydronephrosis was Grade 1 in 56 RU (28%), Grade 2 in 51 RU (26%), Grade 3 in 50 RU (25%) and Grade 4 in 41 RU (21%). 178 RU (90%) were followed conservatively, while open dismembered pyeloplasty was the initial therapeutic approach in 20 RU (10%). The mean age at the time of surgery was 15.95+/-14.60 weeks (range 2-60). Indications included low differential renal function (DRF) (n=12), absence of tracer clearance from the renal pelvis (n=2), parental preference (n=3), and acute renal failure (n=3). Postoperative course was uneventful during 33.43+/-33.53 months (range 2-120) with favorable US and RFS results. In conservatively managed patients, mean follow-up time was 14.94+/-14.35 months (range 1.5-142). Spontaneous resolution of hydronephrosis was observed in 87 RU (49%), while 10 RU (5.6%) eventually required surgery for worsening appearance or function on US or RFS, respectively (n=8), symptom development (n=3), and/or parental preference due to persistently prolonged T1/2 (n=4). Seventy-two RU (40.4%) remain under surveillance with improvement (47.2%) or stable hydronephrosis (47.2%) in 94.4%. Decreased DRF occurred in 1 RU. Nine RU (5%) were lost to follow-up. With application of this algorithm, only 12% of patients underwent two or more RFS.
CONCLUSION: Pyeloplasty may be performed safely in infants when indicated; however, the majority of children with UPJO can be managed conservatively. Spontaneous resolution of hydronephrosis and/or favorable prognosis was encountered in 87% of conservatively managed RU. The use of a standard US grading system, selective utilization of follow-up renal function testing, and parental compliance are important factors in successful management.