Clinical Spectrum of Posterior Urethral Valve Obstruction in Children

Transcription

1 Clinical Spectrum of Posterior Urethral Valve Obstruction in Children S ROY CHOUDHURY 1 R CHADHA 2, A PURI 3, A PRASAD 4, A SHARMA 5 A KUMAR 6 Children with posterior Urethral valve (PUV) obstruction constitute a significant number of hospital admissions in our Pediatric Surgery Unit. We present a single institution experience in the management of children with PUV. Over the past three years ( ) 90 patients with PUV were treated in our hospital Majority of them presented in the first year of life. Seventy one percent (64/90) had renal failure at presentation. Voiding cystourethrography (VCUG) was the mainstay of the diagnosis. Associated vesicoureteric reflux (VUR) was present in (51/90) 56% of cases, and was mostly unilateral (90%). After initial per urethral catheter drainage, 75% showed an improvement in the renal function. Primary urethral fulguration of valve was done mostly in older children whereas neonates and non-responders to catheter drainage underwent vesicostomy. The high incidence of diversion in our series was due to non-availability of adequate size resectoscope. Short-term follow up showed adequate growth and nutrition in children on vesicostomy with recovery of renal function. However, a significant number of renal units (90% unilateral and 10% bilateral) showed poor function with functional obstruction in DTPA scan. This report highlights the treatment protocol and problems faced in the management of children with PUV in a Paediatric Surgical Unit of a medical college hospital set-up. Key words : Posterior urethral valves, Urinary diversion, Vesicostomy Management of children with PUV obstruction is an ongoing challenge in Paediatric Surgery. The effect of obstruction on the bladder and on renal function determines the morbidity of this condition. Department of Pediatric Surgery, Kalawati Saran Children's Hospital, Lady Hardinge Medical College, New Delhi ,2,6 Assosiate Professors 3,4,5 Senior Research Associates Prenatal diagnosis provides excellent potential for early diagnosis and counselling with the possible decision to terminate the fetus with severe renal and pulmonary dysplasia. Young 1 classified the Dr S Roy Choudhury Associate Professor of Pediatric Surgery F-81 Ansari Nagar New Delhi roychouin@yahoo.co.in

2 CLINICAL SPECTRUM OF PUV OBSTRUCTION 149 morphological variation of the valvular obstruction into three types. Recently Dewan 2 have identified it as a single obstructing membrane with a small defect or opening in the posterior midline of the urethra and prefers to call the entity "Congenital Obstructing Posterior Urethral Membrane or COPUM". Perinatal mortality from PUV has reduced from 50% to 0-10% due to prenatal diagnosis, elective termination of pregnancy and better perinatal care. 3 Long term results are currently under evaluation. 4 We present our past three years experience in the management of children with PUV. Materials and Methods The records of 90 patients with PUV treated over the past three years ( ) in the Department of Paediatric Surgery, Kalawati Saran Children's Hospital, Lady Hardinge Medical College, New Delhi, were reviewed. The age at presentation, functional status of the kidneys, diagnostic radiology, initial management and short-term follow up were analyzed. Age at presentation is shown in Table I. Renal failure at presentation (serum creatinine> lmg%) was noted in (64/90) 71% of our cases. Fourteen cases (15.5%) below the 1 year age group presented with acute renal failure requiring peritoneal dialysis. Antenatal diagnosis of hydronephrosis was recorded in only five cases (5.5%). The common presenting features in neonates and infants were poor urinary stream, dribbling, retention of urine, palpable bladder, renal lump, urinoma and urinary ascites. Two neonates presented with massive abdominal distension and respiratory distress due to urinary ascites and underwent laparotomy with the mistaken diagnosis of intestinal obstruction. The presenting features in older children were voiding dysfunction, diurnal eneuresis and ftequent UTI. Our initial management included per urethral catheter drainage with no 6 or 8 infant feeding tube, prophylactic antibiotics, serial monitoring of blood urea and serum creatinine, urine sample for culture and sensitivity. Diagnostic radiology consisted of ultrasound scan and VCUG. Varying degrees of hydronephrosis, hydroureter and thick walled bladder were noted in almost all cases in the ultrasound scan. Dilated posterior urethra was appreciated in only a few cases. VCUG was diagnostic showing varying degrees of dilatation of the posterior urethra, thick walled trabeculated bladder with occasional bladder diverticulum and vesicoureteric reflux (VUR) in (51/90) 56% of cases. VUR was mostly unilateral (90%) with equal left and right side distribution. Results With per urethral catheter drainage, 75% of patients showed improvement of renal function (fall in serum creatinine level). Primary valve fulguration was done in 20 patients, vesicostomy and delayed fulguration was done in 30 and 34 are currently on vesicostomy awaiting fulguration and vesicostomy closure. Two patients were converted to ureterostomy due

3 150 J INDIAN ASSOC PEDIATR SURG VOL 8 (JUL-SEP 2003) to deterioration on vesicostomy. Three patients died from intractable urosepsis and renal failure. Post operatively all children with dilated upper tract were kept on prophylactic antibiotics. Our policy is to treat UTI with three different antibiotics cyclically to avoid development of resistance. Positive urine culture was noted in 44% of cases at follow up. Post drainage renal functional assessment (DTPA scan) showed unilateral poorly functioning kidney in (31/ 34) 90% cases (equal left and right side distribution), and 10% bilateral poor function. Dilated upper tract with functional obstruction was a common finding (90%). Vesicostomy complications included frequent local site infection, stenosis requiring revision in three cases and mild prolapse in two cases. Some degree of renal failure persisted in (8/34) 24% of patients with vesicostomy. However, the growth and nutrition of patients on vesicostomy appears to be satisfactory. Discussion The reported incidence of PUV is 1 in 8000 to 1 in live births. 5 In our institution with about 1200 pediatric surgical admissions per year we see approximately 30 cases of PUV annually. The majority presented in the first year of life (69/90, 77%) which is consistent with other reports. 6,7 The reported incidence of renal failure at presentation varies from 66% 8 to 90% 9 ; 71 % of our cases had renal failure at presentation of which 15.5% had acute renal failure requiring initial peritoneal dialysis. Urinoma and urinary ascites are the result of renal forniceal leakage of urine. 10 Although blood urea nitrogen and S.creatinine levels are higher in cases of urinary ascites "this Pop-off mechanism preserves the kidney from excessive pressure and hence is a good prognostic sign. 11,12 Simple bladder drainage or vesicostomy improves the condition and transurethral fulguration of valves can be done subsequently. 13 All our cases of urinoma and urinary ascites were initially managed with per urethral catheter drainage followed by vesicostomy and all except one showed improvement of renal-function. Two neonates with tense ascites and respiratory distress improved following drainage of ascites and vesicostomy. Our protocol of management consisted of per urethral catheter drainage, prophylactic antibiotic, serial monitoring of blood urea, serum creatinine and urine sample for culture/ sensitivity. VCUG was done under antibiotic cover. The posterior urethral changes in VCUG vary from very minimal to severe dilatation. Imaji et al 7 classified the findings of VCUG into four groups according to the changes in the urethra, bladder and upper tracts. A high index of suspicion is necessary to diagnose PUV as the radiological findings in VCUG may not be apparent in all cases and they do not necessarily correlate with the endoscopic appearance. Older children with voiding dysfunction particularly diurnal eneuresis and UTI should undergo VCUG to look for PUV. 14 Refinements in instrumentation have made it possible to do per urethral fulguration of valves even in neonates. Those patients who failed to respond to per urethral catheter drainage, associated massive VUR, massive urinary leakage, required diversion. 15 We had a high rate of diversion due to nonavailability of neonatal resectoscope.

4 CLINICAL SPECTRUM OF PUV OBSTRUCTION 151 However, our patients on vesicostomy showed satisfactory growth pattern and similar observations have been reported by others. 16,17 As an initial procedure, vesicostomy is superior to ureterostomy not only because it is easy to construct but also provides better bladder cycling. 18 Supravesical diversion can be reserved for those patients who fail to respond to vesicostomy. According to Farag et.al. 9 bilateral ureterostomy may be a better alternative in developing countries like India for patients with persistently high serum creatinine level after bladder drainage, severe urosepsis and urinary ascites. There are conflicting reports on the effect of vesicostomy on subsequent bladder function. Kim et al. 19 found that temporarily diverted bladder had better compliance, larger functional capacity and less irritability. Although, reports are available suggesting no adverse effect of diversion, 20 a non compliant bladder as a result of diversion has been noted by others 21, 22. Length of diversion and vesical infection causing fibrosis decreases the compliance of the bladder. Renal functional scan (DTPA) at follow up in our patients showed persistent upper tract dilatation (mostly unilateral) with functional obstruction in a large number of patients, however, its long term effect is yet to be determined. Association of VUR has been noted in two third of patients with PUV of which one third are bilateral. 15 Prognosis of bilateral reflux is worse; however, unilateral massive reflux has been regarded as a pop-off mechanism to protect the opposite good functioning kidney, and hence a better prognostic signs. 11 Half of our patients had VUR, of which 90% unilateral (equal number on the left and right side) and 10% bilateral. We have followed conservative management for VUR and have not so far done any nephrectomy or reimplantation. Several factors have been associated with the long-term prognosis like age at presentation, 9 initial modality of treatment, 8,22 bilateral VUR, 15 diurnal incontinence at age of 5 years 4, serum creatinine level after a period of urinary tract decompressions. Renal failure in PUV is a combined result of infection, backpressure and dysplasia. Despite the type of primary surgical treatment (fulguration, vesicostomy, or high urinary diversion), renal failure still develops in 50% of children with PUV. 23 Availability of neonatal resectoscopes has changed the initial mode of treatment in favour of per urethral fulguration of valves. However a selected group of patients still require urinary diversion. A systematic stepwise approach in the management with reference to individual case is essential for optimal recovery of renal function. The longterm outcome still depends on the degree of renal damage, upper tract changes and bladder dysfunction. 1 Young HR, Frontz WA, Baldwin JC. Congenital obstruction of the posterior urethra. J Urol 1919; 3: References 2 Dewan PA. Congenital obstructing posterior urethral membrane (COPUM) : further evidence for a common morphological diagnosis. Pediatr Surg Int 1993; 8:45-50.

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