Vesicoureteric reflux: Case

This child has grade IV left vesicoureteric reflux with an established upper-pole renal scar, recurrent febrile infection, and a clear picture of bladder and bowel dysfunction. The grade IV is defined by the moderate dilatation and tortuosity of the ureter, the obliteration of the calyceal fornices, and the preservation of the papillary impressions on the micturating cystourethrogram. The cortical defect on the DMSA scan confirms reflux nephropathy, and the split function of 42 percent on the left reflects the functional loss from the scar. The three febrile infections in 10 months, despite intermittent treatment, signal that the conservative approach has failed and that a structured management plan is needed. [1]

Clinical findings

The key clinical findings are the recurrent febrile infections, the grade IV reflux on the left, the upper-pole cortical scar, the blood pressure on the 90th centile, and the bladder and bowel dysfunction. The three febrile infections in 10 months place this child in the highest risk category for progressive scarring, and the existing scar is evidence that the damage has already begun. The split function of 42 percent on the left is modestly reduced, which indicates that the scar has affected the function of the left kidney, and the blood pressure on the 90th centile is a warning sign that the reflux nephropathy may already be driving an early hypertension. [8]

The bladder and bowel dysfunction is a critical finding. The daytime urgency, the infrequent voiding of three times a day, and the chronic constipation are the classic triad, and Elder and Diaz showed that this constellation is present in over 40 percent of children with reflux. The dysfunctional bladder generates high storage and voiding pressures that drive the reflux and the recurrent infection, and the loaded rectum compresses the bladder and worsens the voiding pattern. The bladder and bowel dysfunction is the strongest predictor of conservative management failure, and its treatment is the first priority. [5]

Investigations and diagnosis

The diagnosis of grade IV left vesicoureteric reflux with reflux nephropathy is established. The micturating cystourethrogram is the gold standard for the grading, and the grade IV is defined by the International Reflux Study criteria. The DMSA scan confirms the cortical scarring at the upper pole and the reduced split function. No further diagnostic imaging is needed at this stage, but the surveillance plan includes the periodic blood pressure, the annual urinalysis for proteinuria, and the periodic serum creatinine. [1]

The blood pressure on the 90th centile warrants close monitoring. A child with reflux nephropathy and a blood pressure above the 90th centile for age needs ambulatory or repeat blood pressure monitoring to confirm whether the hypertension is sustained, and an ACE inhibitor or an angiotensin receptor blocker is commenced if the hypertension is confirmed. The proteinuria is screened with the urinalysis, and its presence signals the hyperfiltration injury in the remaining nephrons that drives the progression to chronic kidney disease. [8]

Management and outcome

The management follows the ladder, but it begins with the treatment of the bladder and bowel dysfunction. The child is started on timed voiding, with a watch or a reminder to void every 2 to 3 hours, to overcome the infrequent voiding pattern. The constipation is treated with a macrogol laxative and a high-fibre diet, and an anticholinergic medication such as oxybutynin is added for the overactive bladder with the urgency. The correction of the bladder and bowel dysfunction may reduce the reflux and the recurrent infection, and it is the prerequisite for any successful surgical correction. [5]

The child is started on continuous antibiotic prophylaxis with trimethoprim at 2 mg per kg at night. The RIVUR trial evidence supports this: prophylaxis halved the rate of recurrent febrile infection from 23 percent to 13 percent in the RIVUR Trial Investigators study. However, this child has already had three infections, and the family is counselled that if she has a breakthrough febrile infection despite the prophylaxis, the next step is surgical. [2]

Given the grade IV reflux, the recurrent infection, and the existing scarring, the surgical option is discussed early with the family. Endoscopic injection of dextranomer and hyaluronic acid copolymer is the less invasive option, but its success rate for grade IV reflux is lower than for the lower grades. Open ureteric reimplantation, with a success rate of 95 to 98 percent, is the most durable option and is the preferred choice for the high-grade reflux with recurrent infection and scarring. The family is counselled on the risks and the benefits of each option, and the decision is made jointly with the paediatric urologist. [3]

The long-term outcome is determined by the renal scarring. The cortical defect at the upper pole is permanent, and the scar carries a life-long risk of hypertension and chronic kidney disease. The blood pressure is monitored at every visit, and an ACE inhibitor is commenced if the hypertension is confirmed. The surveillance includes the annual urinalysis for proteinuria and the periodic serum creatinine, and the transition to adult nephrology care is planned in adolescence, because the reflux nephropathy persists and the adolescent girl with a scarred kidney has an additional risk of pre-eclampsia in pregnancy. [8]