OBSTRUCTIVE UROPATHY -Dr. S.N Uwaezuoke, FWACP

INTRODUCTION The renal parenchyma and the tracts are essentially made up of tubular structures. It is therefore not surprising that obstruction is an inevitable problem with its attendant complications. The renal parenchyma and the tracts are essentially made up of tubular structures. It is therefore not surprising that obstruction is an inevitable problem with its attendant complications.

INTRODUCTION II Obstructive lesions of the urinary tract can occur at any level from the urethral meatus to the infundibula of the calyces. Obstructive lesions of the urinary tract can occur at any level from the urethral meatus to the infundibula of the calyces. Obstructive nephropathy occurs as a result of obstruction from the ureteropelvic junction to the infundibula. Obstructive nephropathy occurs as a result of obstruction from the ureteropelvic junction to the infundibula. Obstructive uropathy occurs as a result of obstruction from the level of the urethra to the ureters. Obstructive uropathy occurs as a result of obstruction from the level of the urethra to the ureters.

INTRODUCTION III Depending on the duration of obstruction, the effects of obstruction at the lower urinary tract may be similar to the picture obtainable in upper tract obstruction. Depending on the duration of obstruction, the effects of obstruction at the lower urinary tract may be similar to the picture obtainable in upper tract obstruction. For instance, hydronephrosis may complicate urethral obstruction as well as ureteropelvic junction obstruction. For instance, hydronephrosis may complicate urethral obstruction as well as ureteropelvic junction obstruction.

INTRODUCTION IV The obstructive lesions causing obstructive nephropathy or uropathy are mostly congenital but may also be acquired. The obstructive lesions causing obstructive nephropathy or uropathy are mostly congenital but may also be acquired. Obstructive uropathy is a common cause of chronic renal failure in children. Obstructive uropathy is a common cause of chronic renal failure in children. The pathophysiologic effects of obstruction include stasis leading to dilatation and infection as well as increased pressure within the obstructed system. The combination of stasis, repeated infections and high intramural pressure injures the renal parenchyma causing scarring and progressive renal disease The pathophysiologic effects of obstruction include stasis leading to dilatation and infection as well as increased pressure within the obstructed system. The combination of stasis, repeated infections and high intramural pressure injures the renal parenchyma causing scarring and progressive renal disease

CAUSES OF OBSTRUCTIVE UROPATHY/NEPHROPATHY Meatus- meatal stenosis, phimosis Meatus- meatal stenosis, phimosis Anterior urethra- diverticulum, stricture,valves,polyps Anterior urethra- diverticulum, stricture,valves,polyps Posterior urethra- posterior urethral valve,diverticulum,stricture,polyps Posterior urethra- posterior urethral valve,diverticulum,stricture,polyps Bladder- diverticulum,bladder neck hypertrophy,calculi,neuropathic bladder Bladder- diverticulum,bladder neck hypertrophy,calculi,neuropathic bladder Ureterovesical junction- ureterocele,primary megaureter,calculi Ureterovesical junction- ureterocele,primary megaureter,calculi

CAUSES CONTD Ureter- stricture,calculi,vascular obstruction Ureter- stricture,calculi,vascular obstruction Pelviureteric junction- intrinsic abnormalities,kinks,bands,adhesions, aberrant vessels, calculi Pelviureteric junction- intrinsic abnormalities,kinks,bands,adhesions, aberrant vessels, calculi Calyx- infundibular stenosis,tuberculosis,calculi Calyx- infundibular stenosis,tuberculosis,calculi

DIAGNOSTIC EVALUATION OF OBSTRUCTIVE UROPATHY ULTRASONOGRAPHY ULTRASONOGRAPHY 1. Ultrasound scan- urinary tract dilatation,renal cortical thickness,tumor,calculi 2. Doppler- aberrant vessels

EVALUATION CONTD RADIOCONTRAST STUDIES. RADIOCONTRAST STUDIES. -Intravenous urography (IVU) Hydrocalyx,hydronephrosis,calculi,and ureterocele. Hydrocalyx,hydronephrosis,calculi,and ureterocele. -Micturating cystourethrogram (MCU) Bladder and urethral obstruction,and vesicoureteral reflux Bladder and urethral obstruction,and vesicoureteral reflux -Retrograde urethrography Urethral obstruction Urethral obstruction

RADIONUCLIDE STUDIES DMSA (Dimercaptosuccinic acid) scan DMSA (Dimercaptosuccinic acid) scan -Renal scarring Radionuclide cystogram Radionuclide cystogram -Vesicoureteral reflux, bladder outlet obstruction DPTA scan DPTA scan -Upper tract function, obstruction, differential function, GFR

ENDOSCOPY Direct visualization of lesions Direct visualization of lesions Therapeutic applications Therapeutic applications

COMPLICATIONS OF OBSTRUCTION URINARY TRACT INFECTIONS URINARY TRACT INFECTIONS HYPERTENSION AND PROTEINURIA HYPERTENSION AND PROTEINURIA STONES (Struvite and Calcium phosphate) STONES (Struvite and Calcium phosphate) TUBULAR DYSFUNCTION TUBULAR DYSFUNCTION -Poor urinary concentration -Poor urinary concentration -Salt wasting -Salt wasting -Urinary acidification defect (distal RTA) -Urinary acidification defect (distal RTA)

POSTERIOR URETHRAL VALVES Refers to congenital valves in the posterior urethra, located just distal to the verumontanum at the junction of the anterior and posterior urethra Refers to congenital valves in the posterior urethra, located just distal to the verumontanum at the junction of the anterior and posterior urethra Commonest cause of lower urinary tract obstruction (obstructive uropathy) in male children Commonest cause of lower urinary tract obstruction (obstructive uropathy) in male children

MAJOR TYPES OF PUV Type 1- the commonest type.Valves appear to radiate distally from the verumontanum, merging into each other to form an anterior commissure. Obstruction to the flow of urine is produced by a ballooning effect, but retrograde catheterization does not meet any resistance Type 1- the commonest type.Valves appear to radiate distally from the verumontanum, merging into each other to form an anterior commissure. Obstruction to the flow of urine is produced by a ballooning effect, but retrograde catheterization does not meet any resistance

TYPES OF PUV Type II-Valves spread proximally, usually undetected. The flow of urine is not obstructed Type II-Valves spread proximally, usually undetected. The flow of urine is not obstructed Type III-Valves consist of a circular diaphragm with a central hole. Is usually treated when retrograde catheterization tears the valves Type III-Valves consist of a circular diaphragm with a central hole. Is usually treated when retrograde catheterization tears the valves

SEQUELAE OF PUV The obstruction to urine flow causes dilatation of the posterior urethra and hypertrophy of the bladder neck. The obstruction to urine flow causes dilatation of the posterior urethra and hypertrophy of the bladder neck. Bladder wall thickens and shows trabeculations. Bladder wall thickens and shows trabeculations. Gross reflux into the ureters with associated pyelonephritis and reflux nephropathy Gross reflux into the ureters with associated pyelonephritis and reflux nephropathy

CLINICAL FEATURES The infant presents with features of obstruction such as dribbling of urine, weak stream, straining, retention and a palpable bladder The infant presents with features of obstruction such as dribbling of urine, weak stream, straining, retention and a palpable bladder May also present with features of recurrent urinary tract infection such as fever, dysuria, hematuria, vomiting and failure to thrive May also present with features of recurrent urinary tract infection such as fever, dysuria, hematuria, vomiting and failure to thrive Varying degree of renal function impairment may be present Varying degree of renal function impairment may be present

Investigations Confirmatory test- MCU which shows a dilated posterior urethra, poor urine flow into the distal urethra and abnormalities of the bladder. Vesicoureteral reflux, bilateral hydroureter, and hydronephrosis may be present. Confirmatory test- MCU which shows a dilated posterior urethra, poor urine flow into the distal urethra and abnormalities of the bladder. Vesicoureteral reflux, bilateral hydroureter, and hydronephrosis may be present. Laboratory test to evaluate renal function- serum electrolyte, urea and creatinine Laboratory test to evaluate renal function- serum electrolyte, urea and creatinine

MANAGEMENT Temporary urinary drainage- transurethral catheter, suprapubic catheterization,vesicotomy. Temporary urinary drainage- transurethral catheter, suprapubic catheterization,vesicotomy. Aggressive treatment of urinary tract infections with intravenous antibiotics. Aggressive treatment of urinary tract infections with intravenous antibiotics. If renal function does not improve despite initial drainage, control of infection and rehydration, bilateral ureterostomy is done If renal function does not improve despite initial drainage, control of infection and rehydration, bilateral ureterostomy is done

MANAGEMENT CONTD Once renal function improves, endoscopic ablation of the valve is performed Once renal function improves, endoscopic ablation of the valve is performed Long term follow up because of the risk of chronic renal failure Long term follow up because of the risk of chronic renal failure

THANK YOU FOR LISTENING FURTHER READING-Pediatric Nephrology by RN Srivastava and Arvind Bagga 4 th edition FURTHER READING-Pediatric Nephrology by RN Srivastava and Arvind Bagga 4 th edition