Posterior urethral valves (PUV) constitute the most common infravesical urinary obstruction in boys. PUV are often accompanied by severe consequences to the lower urinary tract. High voiding pressures are seen in infants around the ablation of the valves. Detrusor overactivity, which is frequent in infancy, has a tendency to become underactive with age. Accordingly, hypocontractibility and myogenic failure have been reported in older children. Successive increase in bladder capacity is suspected to be accompanied by a risk for overdistention. This concept of changing urodynamic patterns leads to the need to assess the possibility of using drugs that reduce detrusor pressure and determine other recovery tactics.

42 boys after PUV ablation in infancy were followed up for 10-16 years. In 24 of them, the upper urinary tract was mainly retracted compared to the primary valve resection in others. Thus, the temporary or permanent decrease in bladder volume that was observed in these patients with defunctionalized bladder may have been secondary due to the diversion of the cutaneous ureterostomy. In 18 patients PUV were accompanied by VUR, in 24 there were besides nonobstructive megaureter. Diagnostic based on US, VCUG, DMSA and MAG3 scintigrapy investigations. Staged urodynamic studies were conducted on all boys 3-5 times at different ages.

Initially, all patients have high pressure in the bladder.

Only 2 of them recorded a decrease in urinary pressure during the first months spontaneously after the PUV incision.  Most patients required primary postoperative treatment with oxybutynin (19), adrenergic blockers (35), and botulinum therapy of detrusor was performed in 3 patients.
To the age of 3-4 years old following the release of the valvular obstruction urodynamic patterns in patients with PUV were as follows: detrusor overactivity with median cystometric bladder capacity (CBC) of 42 ml (range 15 to 72) and maximal detrusor pressure during voiding (Pmax det) 112 cm H2O (range 40 to 331). – in 25 boys, low bladder compliance with mean bladder volume 35ml (20-42ml) – in 13,  myogenic failure (detrusor underactivity with poor detrusor reflex  or completely without it) – in 4. 
This led to the need for prolongation of anticholinergic therapy in 29 boys and botulotoxin injections in 12, which led to an increase of residual urine in 50% of patients (20).  At the same time, the addition of biofeedback therapy and noninvasive tibial neuromodulation made it possible to achieve good results of emptying the bladder in 28 boys of elder ages without oxibutinin. 
Finally in teenagers, the 5 patients came to CIC without any additional medication therapy, 3 – have done CIC accompanied by oxibutinine, 7 need to prolog medication therapy with adrenergic blockers  for improving the micturition, others were completely rehabilitated.

Lower urinary tract dysfunction (LUTD) is known to be common in PUV patients.  It is worth thinking about and being wary of the use of m-anticholinergics and botulinum toxin in this category of patients, since most of them programmatically develop detrusor underactivity and violation of bladder emptying, which can be aggravated by these drugs. Urotherapy, neuromodulation and biofeedback therapy are the useful tools in management of patients with PUV and must be used widely.

Continence 2S2 (2022) 100439
DOI: 10.1016/j.cont.2022.100439