Delayed decrease in differential renal function after successful pyeloplasty in children with unilateral antenatally detected hydronephrosis

Abstract

Aim:The aim of this study was to evaluate functional outcome of congenital hydronephrotic kidney. Methods: The records of consecutive children who underwent pyeloplasty for unilateral prenatally detected ureteropelvic junction obstruction were reviewed. Renal function was assessed renographically before and after surgery. Mean follow-up period was 100 months. Results: Sufficient pre-and postoperative data were available for 60 children. Differential renal function (DRF) improved in 14 (23%) and decreased in nine (15%) of 60 patients in the early postoperative period. DRF improved in seven (18%) and decreased in 13 (34%) of 38 patients at the end of follow-up. Five of 14 patients with increased DRF at early postoperative scan returned to the preoperative level at the end of follow-up. No patients with decreased DRF at early postoperative scan showed any recovery in DRF and progressive decrease was seen in four of nine children. Conclusions:The DRF was not stable in some patients after successful pyeloplasty. In some patients impairment of renal function came to be apparent with time. Improvement of DRF may be a transient phenomenon seen in the early postoperative period. To avoid overestimation of functional recovery, long-term follow-up with delayed renographic evaluation is recommended.

Long-term follow-up and management of prenatally detected, isolated hydronephrosis

“…The longest follow-up after pyeloplasty was almost 16 years, and renal function appeared to be stable with no worsening of hydronephrosis according to Chertin et al [7]. However, Matsumoto et al [28] reported that DRF was not stable in some patients after successful pyeloplasty, and in some patients, the impairment of renal function became more apparent with time. We previously observed that the follow-up period was positively correlated with renal function recovery, and the renal function recovered 3 to 9 months postoperatively and was stable by 1 year [29].…”

Urine neutrophil gelatinase-associated lipocalin (NGAL) measurement is not predictive for ureteral patency in pediatric patients following pyeloplasty: a pilot study

“…A significant number of patients demonstrate stable hydronephrosis on ultrasound, while renal scanning shows an improved DRF 15 . In general, the renal scan is accepted as a gold standard for evaluating improvement in renal function after pyeloplasty, with a change of 5% considered as significant 14 . However, this imaging modality requires a significant exposure of ionizing radiation to the patients 18 which may negatively affect organ maturation in the long-term.…”

“…At six months, a voided midstream urine specimen (BU2) was collected at the clinic, and MAG-3 renal scan was performed to measure the postoperative DRF and the diuretic half-time clearance. In this study, ureteral patency was defined by the improvement of more than 5% of DRF 14 or the conversion of diuretic half time to less than 20 minutes.…”

Pediatric congenital hydronephrosis (ureteropelvic junction obstruction): Medical management guide

“…[78][79][80] Although renal function might change several years after surgery, it has been reported that renal function stabilizes within approximately 5 years and is maintained for a long time thereafter. [81][82][83][84] However, decreased renal function has been observed in 0-28% of patients, and recurrence is seen after ≥5 years in 1.3-4% of patients. 75 The degree of usefulness are expressed as follows: ★★★, standard; ★★, compliant with standard; ★, optional; ▲, not recommended; ☆☆, compliant with the standard, but outside of insurance adaptation in Japan; ☆, optional, but outside of insurance adaptation in Japan.…”

“…DR is not essential, except in cases of suspected aggravation of HN . Although renal function might change several years after surgery, it has been reported that renal function stabilizes within approximately 5 years and is maintained for a long time thereafter . However, decreased renal function has been observed in 0–28% of patients, and recurrence is seen after ≥5 years in 1.3–4% of patients .…”