This document discusses obstructive uropathy in neonates. It presents a case of a preterm baby with bilateral hydronephrosis and a thick bladder wall. Key points discussed include the causes, presentations, investigations, and management of obstructive uropathy. Posterior urethral valves and ureteropelvic junction obstruction are examined in more detail. Vesicoureteric reflux is also summarized. The document emphasizes relieving obstruction, treating infection, and sorting the primary cause in managing obstructive uropathy.
1. Obstructive Uropathy in Neonate
Dr. Shirish Silwal &
Dr. Md. Saiful Islam
Phase A Resident
Dept. of Paediatric Surgery
2. Case Scenario
• Male preterm 36 weeks baby antenataly diagnosed as left
sided hydroureteronephrosis admitted in NICU with
complain of respiratory distress .
• Postnatal USG reveled B/L hydronephrosis ? PUV with
trabeculated and thick bladder wall.
• Serum creatinine 2.94mg/dl
• So paediatric nephrology and pediatric surgery consultation
done.
• Planned for catherterization on 3rd day followed by
• Cutaneous Vesicostomy done on 21st day under GA
4. Obstructive Uropathy
• The structural or functional disorder leading to
impaired urinary flow.
• The obstruction may be in the upper or lower
urinary tracts.
• Will have corresponding signs and symptoms based
on the site, degree of obstruction and duration.
10. TREATMENT PRINCIPLES
BE LOGICAL IN APPROACH
• Relieve Obstruction
• Correct the derangements
that may have occurred.
• Treat any infection
• Sort out the primary cause of
the problem
THE ANSWER MAY NOT BE
STRAIGHT
12. Literary History
1717. Morgagni, first to report a description of PUVs.
1802. However, the most frequently referenced, earliest description of PUVs
is credited to Langenbeck, who commented on valve-like folds in autopsy
specimens, but did not infer any clinical significance.
1870. First comprehensive discussion of valves was raised by Tolmatschew.
First to recognize this as a pathological entity and propose a theory as to its
embryology.
1919. Finally, Young et al reported their series of 12 patients with PUVs,
describing the clinical course, treatment and autopsy findings.
In this study Young et al also created a classification system for valves, which
remains the most commonly used system even today.
13. Introduction
Definition:
Posterior Urethral Valves are mucosal folds at the distal prostatic
urethra that cause varying degrees of obstruction.
• Most common cause of obstruction of bladder outflow in
male neonates and infants.
• Most common cause of Renal Replacement Therapy in
Paediatric group in UK
14. Epidemiology
• PUV affects exclusively in male infants
• Occurs in about 1 : 8,000 births
• Elevated incidence in African-Americans and children with
Down’s syndrome
• 10% of cases of prenatally diagnosed hydronephrosis overall
16. Young Classification
Type I valves (95%)
– Represents sail-like folds from the verumontanum distally along the
urethra
– They are thought to arise owing to the mesonephric ducts inserting
abnormally into the cloaca.
17. Young Classification
Type II valves
– Extend proximally from the verumontanum to the bladder neck.
– Likely have only historical significance and are not considered to be a
clinical entity, but rather hypertrophied urethral folds
18. Young Classification
Type III valve (5%)
– Circular diaphragm distal to the verumontanum at the level of the
membranous urethra.
– Represent a cannulated septum thought by some to represent an
incomplete dissolution of the urogenital membrane
19. Presentation
Variable & Age dependent
• Prenatally : 70% of PUV by Ultrasound
• Newborns: Abdominal mass
Ascites
Respiratory distress
Urosepsis
Delayed voiding or poor stream
• Infants: Urinary dribbling
Enuresis
Failure to thrive/ renal failure
Urosepsis
• Toddlers: UTI, Voiding dysfunction
• School-age boys: Urinary incontinence
21. Diagnosis
• Most commonly made by screening antenatal USG
• Neonatal physical exam may demonstrate a palpable
hypertrophied bladder
• In severe cases, electrolyte abnormalities may lead to seizures
or cardiac arrhythmias.
• Older children may present with incontinence, vague
abdominal complaints, UTI, distended bladder, thin urinary
stream, or hematuria.
22. Investigations
UltraSound is usually the first diagnostic tool
– bilateral hydroureteronephrosis
– a large, thick-walled bladder in severe cases.
IVU can demonstrate the same.
MCUG is the most diagnostic examination
– will show a heavily trabeculated bladder
– prominence of the bladder neck
– dilatation of the posterior urethra
– focal narrowing of the stream at the site of the valves
– Vesicoureteral reflux should be sought
Intraoperatively, endoscopy will visualize the valves if flow from
the bladder is induced by suprapubic pressure
23. Postnatal Management
Includes:
• Stabilization of the patient
• Drainage of the urinary tract
• Correction of electrolyte abnormalities, particularly hyperkalemia
• Intervention to treat respiratory distress, and urosepsis
24. Postnatal Management
Drainage of Urinary Bladder
1. Placement of a catheter in the bladder
• Temporary
• Until patient stabilized
• 8 F feeding tube over Foley’s catheter for better drainage
25. Postnatal Management
Drainage of Urinary Bladder
2. Primary ablation during cystoscopy
• Preferred initial surgical treatment
• Ability to perform this procedure is determined by the size of the
male urethra to accommodate the neonatal cystoscope.
• Timing of this procedure is dependent on the overall health status of
the neonate and issues with GA.
26. Postnatal Management
Drainage of Urinary Bladder
3. Vesicostomy
• performed in infants in whom safe visualization or ablation of the
valves is not possible
• relieves back pressure
• is a reversible procedure
• allows for the normal cyclical filling and emptying of the bladder at
low vesical pressure
27. Postnatal Management
Drainage of Urinary Bladder
4. Higher diversions
• Cutaneous ureterostomies and pyelostomies are rarely indicated
• Do not improve outcomes compared to vesicostomy
• Commits a patient to subsequent major upper tract reconstruction
• Higher diversions disrupt the filling and emptying of the bladder,
which may further impact on bladder function.
28. Post-procedure Management
Starts after a successful procedure that relieves or bypasses the
intervention
1. Detecting and treating bladder dysfunction
Evaluated by imaging and urodynamic studies.
Clean Intermittent Catheterization & Anticholinergic medications
• lowers bladder pressures in patients with severe bladder dysfunction
(ie, low capacity, poorly compliant bladders with high filling pressure).
• may reduce the rate of vesico-ureteral reflux, if present post-ablation
2. Monitoring renal function
3. Managing the consequences of CKD.
29. Outcome
Despite prenatal diagnosis and early intervention, a significant
number of patients will develop
ESRD
Persistent bladder dysfunction
• Detrusor hyper-reflexia (29%)
• Hypertonic and poor compliant bladder (31%)
• Myogenic failure and overflow incontinence (40%)
Reflux is present in 48% to 70% of PUV patients
Persistent Hydronephrosis/Hydroureteronephrosis
High-pressure reflux during the prenatal period may lead to
Renal dysplasia
30. Follow-up
MCUG at 2 months after treatment to ensure destruction of
valves
Regular USG to evaluate resolution of HDN
Ongoing monitoring of renal function is important
• In order to anticipate associated CKD
• Medical conditions that may require intervention
• To provide counseling to patients at risk for ESRD and their
families regarding options for renal replacement therapy
31. Prognosis
• Late Presentation, Cr > 1.0 after 1 month of treatment, Type
III PUV all have worse prognosis
• 30 % cases develop some long term kidney failure
• If associated with oligohydramnios and pulmonary
hypoplasia 50% mortality.
• Postnatal vesicoureteral reflux is present in one-third to one-
half of patients
worse prognosis but one third of these cases resolve spontaneously after
valve ablation
32. Conclusion
• Type I is the most commonest.
• USG and MCUG are the modalities of diagnosis
• Drainage, Antibiotics and correction of metabolic disturbances
is the initial treatment
• Majority are managed by valve ablation
• Basically 2 types of PUV, Type III being with worse prognosis
• Long term sequel significant, regular F/U necessary to
diagnose early Renal Disease.
35. Definition
• A ureteropelvic junction (UPJ) obstruction can be considered a
restriction to flow of urine from the renal pelvis to the ureter,
which if left uncorrected, will lead to progressive renal
deterioration.
36. Epidemiology
• UPJ obstruction is the most common cause of significant
dilation of the collecting system in the fetal kidney (48%)
• Estimated at 1 in 5,000 live births.
• More commonly in boys than in girls.
• Especially in the newborn period, where the ratio exceeds 2 : 1
• Left-sided lesions pre- dominate, particularly in the neonate
(approximately 67%). Bilateral UPJ obstruction in 10% to 40% of
cases.
• Noted in 21% of children with the VATER (Vertebral defects,
imperforate Anus, Tracheoesophageal fistula, and Radial and
Renal dysplasia) association.
38. Intrinsic obstruction
• Mechanical: narrowed →
incomplete embryological
ureteric bud recanalization;
muscular invaginations
overdevelop as flaps or valves.
• Functional: adynamic or
dysfunctional segment →
inability to initiate or conduct
peristaltic waves across the
UPJ.
Figure: Intrinsic narrowing of upper ureter contributing to
ureteropelvic junction obstruction.
39. Extrinsic obstruction
• Vessel or fibrous band
may pass anterior to the
pelvis & ureter: most
common.
• May secondary to
intrinsic disturbance
which produces pelvic
over distension &
rotation.
• High insertion of the
ureter into the pelvis.
Figure: A lower pole–crossing vessel contributes to significant
kinking at the ureteropelvic junction and resultant intermittent
obstruction. Often, when the ureter is mobilized, no evidence of
intrinsic narrowing is found. Insertional anomaly and peripelvic
fibrosis may also be present as secondary obstructive factors.
40. Symptoms & Signs
• Asymptomatic
• Insidious onset of pain
• Sensation of draggaing heavyness that worsen by excessive
fluid intake.
• Enlarged kidney may be palpable.
• Attacks of acute real colic may occur with no palpable
swelling.
• Symptoms of UTI and/or pyelonephritis .
• Post strain hematuria.
1. Bernstein et al, 1988 ; Wolpert et al, 1989
42. Figure: These neonatal ultrasound images come from infants with a history of prenatally detected renal dilation. (A)
This ultrasound is normal for comparison purposes. There are dark renal pyramids (arrow) and no renal pelvic
dilation. (B) This image shows isolated renal pelvic dilation (arrow) (SFU grade I). (C) This image shows dilation of
the renal pelvis (solid arrow) and upper and lower-pole calyces (dotted arrows) (SFU grade II). (D) Calyceal dilation
and cortical thinning are seen (SFU grade IV). (E) Hydronephrosis with peripheral cysts (arrow) indicating dysplasia
is seen. This kidney had no function on renal scan.
The Society for Fetal Urology (SFU) classification is used to
describe the degree of dilation.
43. Management
• Medical Mx: Focused on
a) Maintaining sterile urine.
b) Assessing renal function and the degree of
hydronephrosis.
c) Intervention (Double J stenting) is indicated in
infants and children if clearance half –time (T1/2) >20min,
differential function <40% and ongoing parenchymal thinning
with or without contralateral hypertrophy. Intervention is also
indicated in those with pain, hypertension, hematuria,
secondary renal calculi, and recurrent urinary tract infections.
44. Management (Continued…)
• Surgica Mx:
Principles are:
• Formation of a funnel
• Dependent drainage
• Watertight anastomosis
• Tension-free anastomosis
Either open or laparoscopic pyeloplasty is gold standard for
the treatment of PUJ obstruction. In children, the procedure
of choice is an Anderson-Hynes dismembered pyeloplasty.
46. Vesicoureteric reflux
• VUR refers to the retrograde passage of urine from
the bladder into the ureter.
38% of children with prenatal hydronephrosis .
May presence normal postnatal ultrasound .
Reflux may be present in up to 70% of infants who
present with UTI.
47. • Primary Vesicoureteric Reflux:
Main reason for it is a fundamental deficiency
in the function of the UVJ antireflux mechanism while
remaining factors (bladder and ureter) remain normal or
relatively noncontributory.
• Secondary Vesicoureteric Reflux:
Reflux caused by overwhelming the normal
function of the UVJ. Bladder dysfunction of a congenital,
acquired, or behavioural nature is often the root cause of
secondary reflux.
48. Figure: Components of the competent ureterovesical junction. Those abnormalities
most often implicated in the etiology of vesicoureteral refux are outlined. BOO,
bladder outlet obstruction; NVD, neurovesical dysfunction.
49. International Reflux Study in Children
classification system
Grade I reflux into a non-
dilated ureter.
Grade II reflux into the upper
collecting system but non dilated.
Grade III reflux is present in a
dilated ureter with possible
blunting of calyceal fornices.
Grade IV reflux into a grossly
dilated ureter
Grade V massive reflux with
significant ureteral dilatation and
tortuosity with loss of the
papillary impressions.
50. Surgical Indications
Breakthrough UTI during antibiotic prophylaxis.
Anatomical abnormalities:
– Periureteric bladder diverticulum.
– With the ureter inserting in the diverticulum.
– Grade IV & V in duplicated collecting system.
– Ureteral ectopia inserting in bladder neck or urethra.
– Ureterocele.
– Bladder exstrophy.
– Prune-belly syndrome.
Persistence in adolescence.
Grade V.
Noncompliance to medical treatment.
Ureteral obstruction.
52. URETHRAL STRICTURE
• Exclusively in males
1. Congenital
2. Infections
– secondary to urethritis by catheter
3. Traumatic
– non iatrogenic (20%)
– iatrogenic (60%)
53. • Present with urinary retention
• Diagnosis – suspected from history and PE
• IVU, retrograde urethrography (helpful)
• Endoscopy : direct visualization
TREATMENT
• Diversion (intubated or tubeless)
• Manipulation (intubation, dilation)
• Endoscopic urethrotomy (knife, electrical or laser)
• Repair (excision & re-anastomosis, single staged / multi
staged repair)
54. MEATAL STENOSIS
• Usually as a result of previous episodes of meatitis by
ammoniacal inflammation.
• Associated with balanitis xerotica obliterans.
• No endoscopy.
• Treatment
– ventral meatotomy.
– diagnosis requires instrumental calibration or
observation of voided stream.
55. PHIMOSIS
• Inability to retract foreskin.
• Neonate – physiologic due to
natural adhesions between
prepuce & the glans.
• > 3yr – 90% retractable
• at 17 yr - <1% phimosis
• Secondary phimosis : early
forceful retraction – recurrent
adhesions & cicatrical
preputial ring.
• Tx. circumcision or dorsal slit.
Figure: Conditions associated with the uncircumcised penis. A,
Phimosis due to a preputial ring. B, Paraphimosis with associated
entrapped prepuce behind the glans penis.
56. Some Important Investigation
Plain Abdominal Radiography
1) as a primary study
2) as a scout film in anticipation of contrast media.
Ultrasonography
Ultrasonography is a versatile and relatively inexpensive imaging
modality that has the unique feature of being the only imaging
modality to provide real-time evaluation of urologic organs and
structures without the need for ionizing radiation.
57. Micturating cystourethrogram
1. Evaluation of structural and functional bladder outlet
obstruction
2. Evaluation of reflux
3. Evaluation of the urethra in males and females
4. Gold standard investigation for posterior urethral valve.
58. Retrograde urethrogram
1 Evaluation of ureteral stricture disease
2 Assessment for foreign bodies
3 Evaluation of penile or urethral penetrating trauma
4 Evaluation of traumatic gross hematuria
59. Intravenous urography
• Demonstrate the renal collecting systems and ureters
• Investigate the level of ureteral obstruction in renal units
displaying delayed function
• Demonstrate intraoperative opacification of collecting
system during extracorporeal shock wave lithotripsy or per-
cutaneous access to the collecting system
• Demonstrate renal and ureteral anatomy in special
circumstances (e.g., ptosis, after transureteroureterostomy,
after urinary diversion)
60.
61. Cystourethroscopy
1. Rigid
2. Flexible
Indication
• Cystourethroscopy is used to directly visualize the anterior
urethra, posterior urethra, and the bladder.
• Evaluation of voiding symptoms, surveillance of urothelial
carcinoma, foreign body removal, and assisting in difficult
placement of a catheter.
Diagnosed as Preterm 36 wk obstructive uropathy with CKD .
Histologic evaluation reveals a decrease or complete absence of smooth muscle fibers at the UP
Fibrosis and interruption of the smooth muscle continuity block transmission
of the peristaltic wave, while defective innervation also may play a role
After an attack of acute renal pain a swelling is found . Some hours later, following the passage of a large volume of urine , the pain relieved and the swelling disappears(diet’s crisis).
Marked dilatation and elongation of prostatic urethra (P), with reflux into prostatic ducts (straight arrow) secondary to posterior urethral valves (curved arrow) with bilateral vesicoureteral reflux into dilated ureters (U)