Lower urinary tract changes after early valve ablation in neonates and infants: is early diversion warranted?

Abstract

Purpose: Severe hydronephrosis, high grade reflux and/or renal insufficiency often leads to proximal urinary tract diversion in male infants with posterior urethral valves. Even with this treatment progressive loss of renal function often occurs. Unfortunately with early diversion the bladder, already damaged by in utero obstruction, is also defunctionalized. Alternative treatment with valve ablation in the newborn period and without diversion may facilitate recovery of normal bladder function.

Materials and methods: We retrospectively reviewed the records of infants treated for posterior urethral valves before age 1 year at our institution in the last 8 years. Treatment comprised primary valve ablation in 23 patients and urinary diversion in 8. Preoperative and serial postoperative voiding cystourethrograms were scored for degree of trabeculation, bladder neck hypertrophy and prostatic urethral dilatation in all patients undergoing primary valve ablation. Recovery of bladder and renal function after primary valve ablation was compared to that of patients treated with urinary diversion.

Results: All patients treated with primary valve ablation demonstrated marked improvement or resolution of bladder abnormalities on voiding cystourethrography by 1 year postoperatively. Bladder compliance and volume were statistically better than in patients treated with primary diversion. Upper tract diversion failed to halt progressive renal failure in 5 of the 6 patients who underwent diversion. Similarly primary valve ablation did not stop progressive renal failure in a matched group of patients.

Conclusions: Early ablation of posterior urethral valves results in the recovery of normal bladder appearance and function when performed in the first months of life. Severe renal insufficiency tends to progress even with upper tract diversion. Furthermore, this treatment prevents normal bladder cycling, which may inhibit bladder recovery in the patient with posterior urethral valves.