Endoscopic Valve Ablation Research Articles

Posterior urethral valve: Prognostic factors and renal outcome.

Objective:The aim was to study the outcome of posterior urethral valve (PUV) cases treated by stepladder protocol and the prognostic factors affecting the outcome.Materials and Methods:Hospital records of all PUV patients treated by stepladder protocol between January 1992 and December 2013 were reviewed. The studied parameters were: Age at presentation, serum creatinine, types of surgical intervention, vesicoureteral reflux (VUR) on initial voiding cystourethrogram (VCUG), renal cortical scars, plasma renin activity (PRA), and glomerular filtration rate (GFR).Results:Of 396 PUV patients treated during the study period, 152 satisfied study criteria. The age at presentation ranged from 2 days to 15 years (mean 31.3 months). The mean follow-up period was 5 years (range: 2-18 years). Primary endoscopic valve ablation was the most common initial procedure. Chronic renal failure was seen in 42.7% patients at the last follow-up. Serum creatinine at presentation, initial PRA levels, initial GFR, and PRA levels at last follow-up were significant predictors of final renal outcome. Age at presentation (<1 vs. >1 year), presence/absence of VUR on initial VCUG and renal cortical scars had no significant correlation with ultimate renal function.Conclusion:Our study confirms the high prognostic significance of initial serum creatinine, PRA levels and GFR in cases with PUV. PRA also holds promise in long-term follow-up of these patients as a marker of progressive renal damage.

Role of vesicostomy in the management of posterior urethral valve in Sub-Saharan Africa

ObjectiveTo review the role of vesicostomy in the management of posterior urethral valve (PUV), in neonates and infants, given the limitations for endoscopic treatment in this setting. MethodsA review of 35 patients who presented with posterior urethral valve over a 10-year period. Demographic and clinical information were prospectively recorded on a structured pro forma, and the data extracted analysed using SPSS 11.0. ResultsThe 35 boys were aged 3 days to 10 years (median 3 weeks). Twenty-three (65.7%) had a vesicostomy (age range 3 days–3 years, median 3 weeks). The mode of presentation was poor urinary stream 15 (65.2%), urinary retention 4 (17.4%), and renal failure 6 (26.1%). Main findings were palpable bladder 23 (100%), hydronephrosis 4 (17.4%). Abdominal ultrasound confirmed hydronephrosis and thickened bladder wall, and voiding/expressive cystourethrogram confirmed dilated posterior urethra and vesicoureteric reflux in all 23 patients. Complications following vesicostomy were stoma stenosis 1 (4.3%), bladder mucosal prolapse 1 (4.3%), perivesicostomy abscess 1 (4.3%); there was no mortality. Following vesicostomy, 10 (43.5%) patients had excision of the valves and vesicostomy closure at age 2–8 years (median 4 years). They are well, with normal renal ultrasonographic findings, bladder capacity range 115–280 ml, and normal urea, serum electrolytes, creatinine, at 3 years of follow up. Thirteen (56.5%) are still awaiting valvotomy but have remained well and with normal ultrasonographic renal findings. ConclusionVesicostomy is a useful temporising mode of urinary diversion in neonates and infants with posterior urethral valve (in the absence of unobstructed upper tracts) when facilities for endoscopic valve ablation are not readily available.

Setting the Speed Limit: A Pilot Study of the Rate of Serum Creatinine Decrease After Endoscopic Valve Ablation in Neonates

In neonates with a posterior urethral valve serum creatinine is increased. It decreases after successful relief of obstruction. Clinicians consider urinary diversion if serum creatinine remains increased. However, the optimal rate of decrease of serum creatinine is not defined. We generated useful data on the rate of serum creatinine decrease in neonates with a posterior urethral valve by introducing the idea of a prediction curve. We reviewed the medical charts of 15 consecutive children treated for a posterior urethral valve in the neonatal period at our institute between 2002 and 2007. The 11 children with a delayed diagnosis of a posterior urethral valve were excluded from analysis. Serial serum creatinine levels in the cohort of 15 patients were analyzed to estimate 1) the rate of decrease after valve ablation and 2) the time needed to achieve a nadir. One child died of renal insufficiency on day 10 of life and was excluded from study. Serum creatinine attained a nadir at about age 6 months but 73% of the total decrease occurred within the first 2 months of life, which was also equal to a 45% decrease from the peak values recorded soon after birth. The rate of decrease did not appear to be influenced by the peak values. Children with normal peak creatinine or intercurrent problems did not follow the trend. The rate of decrease in serum creatinine in the first few months of life may provide useful information on the adequacy of valve ablation.

Mohan's valvotome for the ablation of posterior urethral valves

Treatment of posterior urethral valves (PUV) is now most commonly by endoscopic valve ablation, but this is not readily available in our environment. We describe our experience with Mohan's valvotome for the ablation of PUV. All patients with PUV who underwent Mohan's valvotomy over a 28-month period from June 2006 were reviewed. There were 35 patients. The median age was 1.5 years (mean age 3.0 years, range 11 days to 14 years). Eleven (31.4%) and 24 (68.6%) patients received the treatment under local and general anaesthesia, respectively. Adequate relief of obstruction was achieved in all patients with marked improvement in the urinary stream. Complications were recorded in two (5.7%) patients; one was re-operated because of recurrent urinary retention, and the other had urinary incontinence which resolved after 3 months. At follow-up of 1-28 months (median 14 months), three (8.6%) patients had died from sepsis and malnutrition. The 32 (91.4%) surviving have good urinary stream, normal renal function (serum creatinine level <1.5mg/dl) and resolution of hydronephrosis as demonstrated on ultrasound. There was no mortality resulting directly from the use of Mohan's valvotomy. Mohan's valvotome is an effective instrument for the ablation of PUV. It is invaluable in the developing world where paediatric endoscopes are not readily available.

Obstructive uropathy in childhood: A review

Background: Obstructive uropathy is any affection of the urinary tract characterized by impairment of urine flow through the tract and which, if left untreated, will cause progressive renal damage. Aim: To present an update on obstructive uropathy in children with emphasis on the situation in Nigeria. Methods: Contemporary information on the management of obstructive uropathy was obtained by searching the Medline and adding information from the authors\' experience. Results: Obstructive uropathy causes renal impairment in all age groups. The causes in children may be congenital or acquired. The congenital causes include pelvi-ureteric junction obstructions, posterior urethral valves (PUV), urethral atresia, phimosis and meatal stenosis. Associated anomalies include imperforate anus and vertebral malformations. Acquired causes include calculi, post-traumatic and post-inflammatory strictures and meatal stenosis. Some specific manifestations are prune-belly syndrome, hydronephrosis and renal failure. Diagnostic investigations include ultrasonography, intravenous urography, cystography and renography. Recent technological advances have impacted on the treatment of the different lesions. These include in utero vesico-amniotic shunt and endoscopic valve ablation for PUV and minimally invasive techniques for urolithiasis. Nephrectomy may be indicated in a unilateral damaged kidney. Not all lesions require treatment. Criteria to select patients for treatment require definition. Occasionally treatment fails because of pretreatment irreversible renal damage. The resulting end-stage renal failure is an indication for renal transplantation. Conclusion: Obstructive uropathy is an important cause of renal impairment. Contemporary advances in the management are yet to become available in developing countries. Compromise treatment options therefore prevail. Adequate treatment is essential to prevent end-stage renal failure. Port Harcourt Medical Journal Vol. 1 (3) 2007: pp. 137-144

Urodynamic changes in patients with anterior urethral valves: Before and after endoscopic valve ablation

Purpose To retrospectively review a series of children with anterior urethral valves (AUV), with emphasis on patterns of urodynamic change and long-term outcome of endoscopic treatment. Patients and methods We reviewed the medical records of eight patients who had undergone thorough radiological and urodynamic exams before and after treatment. The diagnosis of AUV was based on radiological imaging and confirmed by urethrocystoscopy. The valves were ablated through either transurethral fulguration or resection. The upper urinary tracts were studied by renal scan and ultrasonography before and after the procedure. Bladder function was assessed urodynamically 3 months after surgery. Uroflowmetry was performed as soon as the children were toilet trained. Results Endoscopic ablation of AUV was successful in all cases and no surgical complications occurred. The initial symptoms resolved in all boys. VUR disappeared in two out of three patients, and five children had bladder trabeculation that was resolved after surgery. The final outcome was successful in seven patients (88%). The major urodynamic dysfunction was bladder hypercontractility that resolved following valve ablation. The mean maximum voiding detrusor pressure ( P detmax) decreased from 213.2 ± 17.9 cmH 2O to 80.7 ± 9.9 cmH 2O, 6 months after treatment ( P < 0.001). None of the patients had low-compliant bladder, detrusor instability or myogenic failure. The voiding pattern in all toilet-trained patients was staccato and of an interrupted shape prior to surgery, but changed to a normal bell-shaped voiding pattern following valve ablation. Conclusion AUV should be considered in the differential diagnosis of patients presenting with infravesical obstruction. We recommend endoscopic valve ablation as the treatment of choice.

Does bladder augmentation stabilize serum creatinine in urethral valve disease? A series of 19 cases

Objective This study evaluates the results of bladder augmentation (BA) in 19 boys with posterior urethral valves, especially as regards its efficacy in stabilizing serum creatinine. Patients and methods In the period 1995–2005, 188 patients with urethral valves were surgically managed. Nineteen of these had undergone BA as a part of their surgical management after initial endoscopic valve ablation in 15 and diversion in four boys. The mean serum creatinine at the time of BA was 2.11 mg/dl. Results BA stabilized the serum creatinine in 14 but failed to do so in five boys. A serum creatinine level of more than 2 mg/dl at the time of BA was associated with a significantly worse rate of success. BA as part of an undiversion procedure in three boys was unsuccessful. Conclusion In an economic milieu where renal transplantation is not available for the majority of deserving children, careful selection is required before BA is considered as a surgical solution for the valve bladder. BA, when otherwise indicated, has been beneficial in children with pre-augmentation creatinine up to 2 mg/dl.

A Method to Assess Posterior Urethral Valve Ablation

There are few published reports addressing the assessment of posterior urethral valve ablation. This study was performed to provide a ratio to measure successful treatment of posterior urethral valves. A total of 35 patients with posterior urethral valves were treated by a single surgeon between 1995 and 2004. Of these patients 23 were younger than 1 year at diagnosis and were selected for this study. A urethral ratio was calculated by dividing the posterior urethral diameter by the anterior urethral diameter. A total of 31 males undergoing cystography for urinary tract infections were evaluated as normative controls. The urethral ratio was also measured and calculated for these patients. Median patient age was 1.5 months. In 13 patients preoperative cystograms were available and in 20 patients postoperative cystograms were available for review. Measurements were made of the posterior urethral and anterior urethral diameters. Median preoperative ratio in 13 patients was 8.6. This ratio decreased postoperatively to 3.1 in 15 patients who only required 1 ablation and 8.0 in 5 patients who required a second ablation. After a second ablation the ratio decreased to 3.1. The 5 cases requiring a second ablation were initially managed by cystoscopy and a flexible electrode. None of the patients treated initially with a resectoscope required a second ablation. Urethral ratio was 2.6 in 31 normal males undergoing cystogram for investigation of a urinary tract infection. Calculating urethral ratio in patients with posterior urethral valves allows objective measurement of the technical success of valve ablation.

LONG-TERM FOLLOWUP OF BILATERAL HIGH (SOBER) URINARY DIVERSION IN PATIENTS WITH POSTERIOR URETHRAL VALVES AND ITS EFFECT ON BLADDER FUNCTION

Although valve ablation is the treatment of choice in patients with posterior urethral valves (PUV), temporary high (ureterostomy) diversion remains controversial. In this study we evaluated the effect of bilateral Sober high urinary diversion on renal and bladder function. We retrospectively reviewed the records of 36 patients with PUV who underwent bilateral Sober-type diversion. Following valve ablation urodynamic studies were done in all patients after diversion and repeated after ureterostomy closure. The mean duration of diversion was 55 months. Vesicoureteral reflux (VUR), renal dysplasia, serum creatinine during followup and urodynamic parameters were recorded. All patients underwent endoscopic valve ablation. Renal function impairment at the end of followup was present in 15 patients. Renal dysplasia was found in 10 patients, while VUR was present in 16 at the time of the first urodynamic studies. Urodynamic studies after ureterostomy closure showed well preserved bladder capacity or compliance in 80% and 69% of cases, respectively. About a third of patients showed increased capacity and normal compliance. Univariate analysis showed that VUR, urinary tract infection and renal dysplasia significantly correlated with impaired renal function. On multivariate analysis renal dysplasia was an independent prognostic factor for poor prognosis. In patients with PUV temporary high diversion of the Sober type does not have a negative influence on bladder function. It immediately releases high intrarenal pressures but only improves renal function temporarily and may contribute to postpone the time of end stage renal failure. Renal dysplasia dictates long-term renal outcomes in this group.

Initial and long-term management of posterior urethral valves

Posterior urethral valves are the most common cause of congenital obstructive uropathy, resulting in renal failure in childhood. Nowadays, in most cases, diagnosis is suggested by antenatal ultrasound. However, antenatal intervention has not resulted in a significantly improved outcome. Endoscopic valve ablation is the initial treatment in most of these neonates, but others procedures, like vesicostomy or ureterostomy, can also be justified in some particular cases in order to improve renal function prognosis. Different factors like bladder dysfunction, VUR, polyuria and proteinuria, can be responsible for the slow and progressive deterioration in renal function that some of these patients show over the years. By treating them all, we may prevent or delay the onset of end stage renal disease.

LONG-TERM BLADDER DYSFUNCTION AND RENAL FUNCTION IN BOYS WITH POSTERIOR URETHRAL VALVES BASED ON URODYNAMIC FINDINGS

Posterior urethral valves are the most common cause of congenital obstructive uropathy leading to renal failure in childhood. We investigate the influence of bladder dysfunction on renal function impairment. We retrospectively reviewed the records of 116 patients with posterior urethral valves. After valve ablation urodynamic studies were performed in all patients. The presence of vesicoureteral reflux (VUR), renal dysplasia, serum creatinine during followup as well as urodynamic abnormalities were recorded. Mean followup was 10.3 years after valve ablation. All patients underwent endoscopic valve ablation and urinary diversion was performed in 32. Renal dysplasia was found in 9 patients. Renal function impairment at the end of followup was present in 35 patients. Urodynamic studies showed poor compliance in 30 boys, detrusor overactivity in 44, and poor compliance and detrusor overactivity in 17. Bilateral VUR was found in 17 boys at the time of diagnosis. Urodynamic studies were normal in 23 (20%) patients, of whom 4 had renal failure. Univariate analysis showed that poor compliance and detrusor overactivity had a significant correlation to renal function impairment in addition to bilateral VUR and renal dysplasia. In a multivariate analysis bilateral VUR was an independent prognostic factor for poor prognosis. Bladder dysfunction may contribute to renal function impairment eventually but normal urodynamic findings do not preclude renal deterioration. It is likely that loss of compliance and detrusor overactivity would actually result in a valve bladder reaching its end point function.

Factors affecting outcome in the management of posterior urethral valves

Children with posterior urethral valves (PUV) are at high risk for renal failure (RF). The outcome of renal function is significantly influenced by early diagnosis and the choice of primary therapy. We reviewed the outcome of renal function in 58 children with PUV. The choice of therapy in each case primary valve fulguration, vesicostomy, or high ureterostomy--was individually decided on the basis of the response to initial catheter drainage of the bladder. Patient age at diagnosis varied from newborn to 5.5 years, and follow-up ranged from 1.6 to 6 years (mean 3.9 years). The most common procedure was primary endoscopic valve ablation, which was carried out in 56.8% of cases. The other procedures were vesicostomy in 32.75% and high ureterostomy in 10.45%. Most neonates (66.6%) had RF at presentation, but one-half of them had achieved normal serum creatinine values at last follow-up. The recovery of renal function was lowest (33%) in older children where the diagnosis was delayed. A comparison between two groups of neonates and infants who differed on the basis of creatinine concentrations at 1 year of age suggested a statistically significant trend: children with normal or near-normal serum creatinine (0.8 mg/dl or less) by 12 months of age maintained good renal function at the time of final evaluation (1.0 mg/dl or less). Children with higher creatinine values at 1 year of age continued to have progressive RF. Seventy-five percent of the patients who had undergone early high ureterostomy after failure to respond to initial catheter drainage had regained normal renal function. We conclude that: serum creatinine at presentation is not predictive of subsequent renal function, but the values after a period of urinary-tract decompression are prognostically more useful; delay in diagnosis results in a poor outcome of renal function; and for optimal recovery of renal function, the choice of the primary procedure varies from case to case and can be determined by a systematic, stepwise approach (stepladder protocol).

Posterior urethral valves: the scenario in a developing center

We have reviewed 233 patients with posterior urethral valves treated in a single center in Calcutta, India, over the last 20 years: 37 were neonates, 75 were between 1 and 12 months, 88 were between 1 and 5 years, and 33 were more than 5 years old when first seen. The clinical presentation and methods employed in diagnosis and assessment are described. Primary endoscopic valve ablation was performed in 140 patients (60%). One or other form of diversion was done in 100 (43%), 93 before and 7 either during or after valve ablation. The short- and long-term results have been studied. Eleven patients died during the initial hospitalization, 3 died subsequently, 15 are in end-stage renal disease, 17 are in poor health, and 18 have been totally lost to follow-up. The remaining 169 have been in good health for periods between 1 and 20 years. While our results of primary valve ablation in low-risk patients with responsible parents are as good as anywhere else in the world, we are concerned at our relatively high diversion rate and relatively poor long-term follow up; the methods being adopted to reduce these problems are discussed.