1. HYDRONEPHROSIS

2. HYDRONEPHROSIS Caused by obstruction of the urinary tract
Typically asymptomatic in its early phases
Obstructed kidney secondary to a ureteropelvic junction (UPJ) or ureterovesical junction obstruction
Present as a mass or cause upper abdominal or flank pain on the affected side
Diagnosed prenatally by ultrasonography
*Nelson’s

3. HYDRONEPHROSIS
Degree of hydronephrosis that develops depends on the duration, degree, and site of the obstruction
The higher the obstruction, the greater the effect on the kidneys
earliest changes in the development of hydronephrosis are seen in the calyces
Nausea, vomiting, loss of weight and strength, and pallor are due to uremia secondary to bilateral hydronephrosis
*Smith

4. Etiology Obstruction to urine flow
Intrinsic or extrinsic mechanical blockade, functional defects not associated with fixed occlusion of the urinary drainage system
Mechanical obstruction
At any level of the urinary tract
Normal points of narrowing (ureteropelvic and ureterovesical junctions, bladder neck, and urethral meatus) are common sites of obstruction
Above the level of the bladder
unilateral dilatation of the ureter (hydroureter) and renal pyelocalyceal system (hydronephrosis)
Lesions at or below the level of the bladder
bilateral involvement
*Harrison’s

5. Etiology Hydronephrosis in utero
May be associated with oligohydramnios and associated fetal respiratory complications.
Posterior urethral valves - most common cause of bilateral hydronephrosis in boys
Childhood causes
Congenital malformations (narrowing of the ureteropelvic junction and anomalous (retrocaval) location of the ureter)
Vesicoureteral reflux

6. Incidence and Epidemiology
Fetal hydronephrosis
diagnosed in 1 of 500 routine prenatal ultrasounds
majority resolves by birth or within the first year of life
fetal intervention
rarely necessary, only considered in cases of bilateral hydronephrosis and severe oligohydramnios
Following birth, severe hydronephrosis may be appreciated as a palpable abdominal mass
*Schwartz’s

7. Incidence and Epidemiology
Bilateral hydronephrosis
renal ultrasound and VCUG should be obtained shortly after birth
Unilateral hydronephrosis
both studies can be obtained electively at approximately 1 month of life
Higher risk for pyelonephritis
diagnosed with unilateral or bilateral hydronephrosis:
antibiotic prophylaxis (i.e., amoxicillin, 10 mg/kg per 24 hours)
Pyelonephritis
during the first year of life:
kidney is still immature
leads to permanent deterioration in renal function
*neonates with hydronephrosis are at a higher risk for pyelonephritis

8. Ultrasound
Severity should be graded from 1 to 4 using the Society for Fetal Urology grading scale
GRADE OF HYDRONEPHROSIS
CENTRAL RENAL COMPLEX
RENAL PARENCHYMAL THICKNESS
Intact
Normal 1
Slight Splitting 2
Evident splitting, complex confined within renal border 3
Wide splitting pelvis dilated outside renal border, calyces uniformly dilated 4
Further dilatation of pelvis and calyces
(calyces may appear convex)
Thin

9. Voiding Cystourethrogram
all cases of congenital hydronephrosis and in any child with ureteral dilatation
dilation is secondary to vesicoureteral reflux in 15% of cases
rule out urethral obstruction
In boys; particularly in cases of suspected posterior urethral valves
infravesical obstruction
Infants - bladder may be palpable because of chronic distention and incomplete emptying
Older children - decreased flow with a normal bladder contraction; urinary flow rate can be measured noninvasively with a urinary flowmeter
urethral stricture or an obstructive urethral lesion
urethra cannot be catheterized to obtain a VCUG

10. Excretory Urogram plain film of the abdomen infravesical obstruction
calculi, spinal abnormalities, and an abnormal intestinal gas pattern or severe constipation
infravesical obstruction
bladder wall is irregular or trabeculated because of detrusor hypertrophy
Postvoid film - show residual bladder urine
Ureteral obstruction - collecting system is dilated above the obstruction and the calyces are blunted

11. MR Urography
newest study used to evaluate suspected upper urinary tract pathology
*utilizes the sensitivity of MR imaging to demonstrate fluid (urine), producing urogram-like pictures without the need for contrast media
provides superb images of the pathology
Method:
child is hydrated and given intravenous furosemide
gadolinium-DTPA is injected
routine T1-weighted and fat-suppressed fast spin-echo T2-weighted imaging is performed through the kidneys, ureters, and bladder
* Smith

12. Computed Tomography Non-contrast spiral CT of the abdomen and pelvis
children with a suspected ureteral calculus
standard method of demonstrating whether a calculus (or calculi) is present, its location, and whether there is significant proximal hydronephrosis

13. URETEROPELVIC JUNCTION OBSTRUCTION

14. URETEROPELVIC JUNCTION OBSTRUCTION
An obstruction of the flow of urine from the renal pelvis to the proximal ureter
Resultant back pressure within the renal pelvis may lead to progressive renal damage and deterioration

15. Incidence and Epidemiology
~ 1 in 100 pregnancies
1 in 500 are later diagnosed with significant urologic problems
Found in ~ 50% of patients diagnosed with antenatal hydronephrosis
M:F = 3-4:1
Left kidney > Right kidney
UPJ obstruction is less common in adults than in children but is not rare in either population

16. INTRINSIC OBSTRUCTION SECONDARY UPJ OBSTRUCTION
Etiology
Scarring of ureteral valves
Stenosis
INTRINSIC OBSTRUCTION
Asymmetry of ureteral wall musculature
Abnormal peristalsis
URETERAL HYPOPLASIA
Prior surgery / Failure to repair 1° UPJ OBstruction
Ureteral-wall and periureteral scar formation
SECONDARY UPJ OBSTRUCTION

17. Clinical Presentation
Back pain
Blood in the urine (hematuria)
Failure to thrive
Flank pain
Flank mass
Kidney infection (pyelonephritis)
Urinary tract infection (UTI)

18. Ancillary Procedures CBC count Coagulation profile Electrolyte level
BUN
Creatinine
Urine culture

19. Ancillary Procedures
Intravenous pyelogram demonstrating ureteropelvic junction obstruction with dilatation of the collecting system and lack of excretion of contrast

20. Medical Treatment
Currently, medical therapy is unavailable for the treatment of both adult and pediatric cases of UPJ obstruction
Antibiotics
Prevent infection
Monitored with renal ultrasound every 3 to 6 months

21. Surgical Treatment
Indicated: UPJ obstruction causes a significant reduction in renal function
Pyeloplasty
Remove the obstruction
Improve urine flow
Reduce the risk for kidney damage. Pyeloplasty
Involves removing the blockage and reattaching the ureter to the renal pelvis
Temporary device that holds the ureter open (stent) may be inserted to drain the kidney
Long-term success rates exceeds 95%

22. VESICOURETERAL REFLUX

23. VESICOURETERAL REFLUX
Characterized by the retrograde flow of urine from the bladder to the kidneys.
Associated with UTI, hydronephrosis, and abnormal kidney development (renal dysplasia)

24. Incidence and Epidemiology
17-37% in the pediatric population.
~ 20-30% of children with VUR present with renal lesions
5th most common cause of chronic renal insufficiency in children
VUR is more prevalent in male newborns
BUT, VUR seems to be 5-6 times more common in females older than one year than in males

25. Incidence and Epidemiology
Has a definite genetic component
MOA of inheritance remains unknown

26. Vesicoureteral Reflux

27. Etiology Primary causes Secondary causes
Short or absent intravesical ureter
Absence of adequate detrusor backing
Lateral displacement of the ureteral orifice
Abnormal configuration of the ureteral orifice (eg, stadium, horseshoe, golf hole)
Secondary causes
Cystitis or UTI
Bladder outlet obstruction
Detrusor instability
Duplicated collecting system
Paraureteral (Hutch) diverticulum

28. Grading of Reflux
Grade I results in urine reflux into the ureter only.
Grade II results in urine reflux into the ureter and the renal pelvis, without distention (hydronephrosis).
Grade III results in urine reflux into the ureter and the renal pelvis, causing mild hydronephrosis.
Grade IV results in moderate hydronephrosis.
Grade V results in severe hydronephrosis and twisting of

29. Diagnosis Cystogram (also called cystourethrogram)
Voiding cystourethrogram (VCUG)
Bladder ultrasound
to detect abnormalities that cause reflux
Renal ultrasound and renal scan
to evaluate hydronephrosis, kidney growth, and scarring

30. Clinical Presentation
NEONATES
Respiratory distress
Persistent vomiting
Failure to thrive
Renal failure
Flank masses
Urinary ascites
Severe UTI
OLDER CHILDREN
Symptoms of UTI
Urgency
Frequency
Dysuria
Nocturnal and diurnal enuresis
Other constitutional symptoms include:
Failure to thrive
GI disturbances (eg. nausea, vomiting)

31. Treatment The goals of medical intervention in patients with VUR:
To allow normal renal growth
To prevent UTI and pyelonephritis
To prevent renal failure.
**Initiate medical management in prepubertal children with grades I-III reflux and most children with grade IV reflux.

32. Surgical Treatment Relative indications Grades IV and V reflux
Persistent reflux despite medical therapy (beyond 3 y)
Breakthrough UTIs in patient who are receiving antibiotic prophylaxis
Lack of renal growth
Multiple drug allergies

33. Surgical Treatment Absolute indications Medical noncompliance
Breakthrough pyelonephritis
Progressive renal scarring in patients receiving antibiotic prophylaxis
Associated ureterovesical junction abnormality

34. Surgical Treatment Ureteral Reimplantation or Ureteroneocystostomy
Indicated as a primary procedure if the patient has significant vesicoureteral reflux in the lower pole moiety and a well-functioning upper pole moiety and/or significant contralateral vesicoureteral reflux
This operation is commonly delayed until the child is older (aged approximately 2 y/o)
However, this operation should be performed before the child is toilet trained since it is rather extensive surgery

35. Complications Bleeding Infection
Urinary leakage and bladder spasms shortly after the surgery (usually resolve in 2 to 3 weeks)
Ureteral obstruction
Persistent reflux

36. URETEROCELE

37. URETEROCELE
Saccular out-pouching of the distal ureter into the urinary bladder
Arise from abnormal embryogenesis, with anomalous development of the intravesical ureter, the kidney, and the collecting system
May be asymptomatic or may cause a wide range of clinical signs and symptoms, from recurrent cystitis to bladder outlet obstruction

38. Types of ureteroceles classified by their association with the renal unit
Single-system ureteroceles
associated with a single kidney, a single collecting system, and a solitary ureter
Duplex-system ureteroceles
associated with kidneys that have a completely duplicated collecting system and 2 ureters.
Orthotopic ureterocele
orifice is located in a normal anatomic (orthotopic) position within the bladder
usually arises from a single renal unit with one collecting system and is more common in adults
Ectopic ureterocele
orifices are located in an ectopic position, such as the bladder neck or urethra
arise from the upper pole moiety of a duplicated collecting system and are more common in the pediatric population

39. Classification based on the features of the affected ureteral orifice
Stenotic ureteroceles
located inside the bladder with an obstructing orifice
Sphincteric ureterocele
refers to those that lie distal to the internal sphincter
the ureterocele orifice may be normal or patulous, but the distal ureter leading to it becomes obstructed by the activity of the internal sphincter
Sphincterostenotic ureteroceles
have characteristics of both stenotic and sphincteric ureteroceles
Cecoureteroceles
elongated beyond the ureterocele orifice by tunneling under the trigone and the urethra

40. Etiology Several theories exist, including:
obstruction of the ureteral orifice
incomplete muscularization of the intramural ureter
excessive dilatation of the intramural ureter during the development of the bladder and trigone
Obstruction of the ureteral orifice during embryogenesis, with incomplete dissolution of the Chwalla membrane
the most commonly accepted theory behind ureterocele formation
Chwalla membrane
primitive thin membrane that separates the ureteral bud from the developing urogenital sinus
failure to completely perforate during development of the ureteral orifice is thought to explain the occurrence of a ureterocele

41. Epidemiology 1 in every 4000 children Most commonly in white persons
F:M ratio - 4-7:1
Although a slight left-sided preponderance appears to exist, approximately 10% of ureteroceles occur bilaterally
Ectopic ureteroceles has been reported to be approximately 80% in most pediatric series
Similarly, approximately 80% of ureteroceles are associated with the upper pole moiety of a duplex system
Single-system ectopic ureteroceles are uncommon and are most often found in males

42. Clinical Presentation
Urinary tract infection
Urosepsis
Obstructive voiding symptoms
Urinary retention
Failure to thrive
Hematuria
Cyclic abdominal pain
Ureteral calculus

43. Ancillary Procedures Laboratory Studies Urinalysis Urine culture
Complete blood cell count
Serum chemistries, especially BUN and serum creatinine
Blood cultures
Fungal cultures: obtained in infants who have been on long-term antibiotic therapy or in immunocompromised patients with clinical evidence of UTI

44. Ancillary Procedures Renal or bladder ultrasonography
First-line imaging study for evaluating the upper and lower urinary tract in the pediatric population
Seen as a fluid-filled cystic intravesical mass
Aka "cyst within a cyst"

45. Ancillary Procedures Voiding cystourethrography
Appears as a smooth, round filling defect along the base of the bladder

46. Ancillary Procedures Intravenous pyelography
Useful for delineating renal anatomy and providing a subjective estimation of relative renal function
The following may be seen on IVP:
Hydronephrosis, revealing dilatation of collecting system
Hydronephrotic upper pole displacing the lower pole moiety laterally and inferiorly (ie, the "drooping lily")
Ureteral displacement by the hydroureter or hydronephrotic upper pole moiety
Cobra-head extension of the distal ureter (ureterocele) (seen in adults)

47. Ancillary Procedures
Cystoscopy, vaginoscopy, or retrograde pyelography
Endoscopic procedures that allow direct inspection and examination of the lower urinary tract, as well as the female genitalia
For optimal demonstration of a ureterocele, one must examine the bladder when it is both full and empty
When radiologic suspicion of a ureterocele in an adult is aroused, cystoscopy often confirms radiographic findings
If clinically indicated, the ureterocele may be treated with endoscopic incision or unroofing at the same setting

48. Medical Treatment Medical Therapy
Observation alone is rarely a good option in symptomatic ureteroceles
Must rapidly initiate aggressive antibiotic therapy
Antibiotics should be instituted during the initial diagnostic evaluation and during surgical intervention

49. Surgical Treatment Goals of treatment include the following:
Control of UTI
Preservation of renal function
Protection of ipsilateral and contralateral renal units
Maintenance of urinary continence

50. Surgical Treatment
Surgical approach is selected based on the following:
Age of the patient
Size and location of ureterocele
Degree of renal function
Presence and degree of vesicoureteral reflux
Comorbid conditions (risk of anesthesia)

51. Endoscopic incision
Least invasive method for decompressing the ureterocele
Ideal method for dealing with a neonate with ureterocele-induced obstructive uropathy and sepsis
Definitive therapy in only 10-40% of patients with ectopic ureteroceles, compared to 90% of the patients with a single system intravesical ureterocele

52. Upper pole heminephrectomy and partial ureterectomy
Involves removal of the upper pole of the kidney, as well as the affected proximal ureter to the level of iliac vessels
Remaining distal ureterocele is not excised but rather is decompressed
Definitive treatment in patients with an obstructed ectopic ureterocele and a dysplastic upper pole, but without associated vesicoureteral reflux
Excellent first-line procedure for the child with a ureterocele that affects only the ipsilateral upper pole
Good choice in the child with a ureterocele with only ipsilateral renal involvement (which may include upper pole obstruction and lower pole reflux, for example)

53. Ureteropyelostomy
Operation that joins the upper pole ureter to the lower pole renal pelvis
Preferred if the affected renal unit demonstrates significant function
Alternatively, a high ureteroureterostomy may also be performed
This is true for both pediatric and adult populations

54. Excision of the ureterocele and ureteral reimplantation
Indicated as a primary procedure if the patient has significant vesicoureteral reflux in the lower pole moiety and a well-functioning upper pole moiety and/or significant contralateral vesicoureteral reflux
This operation is commonly delayed until the child is older (aged approximately 2 y/o)
However, this operation should be performed before the child is toilet trained since it is rather extensive surgery

55. Nephroureterectomy
Performed in patients with single system ureterocele and a nonfunctioning kidney
The traditional method of correcting an ectopic ureterocele in a duplex system has been to perform a total reconstruction

56. Complications Endoscopic incision of ureterocele
Iatrogenic VUR occurs in 40-50% of pediatric patients
This is infrequently definitive therapy, except in cases of a single system intravesical ureterocele
Upper pole heminephrectomy
Highest risk of intraoperative blood loss
Vascular compromise of lower pole with potential loss of renal function
Need for further lower tract reconstruction due to persistent reflux, infection, or failure to decompress the ureterocele
Excision of ureterocele and ureteral reimplantation
Problematic hematuria and/or bladder spasms
Damage to bladder neck or continence mechanism
Injury to the contralateral ureteral orifice
Compromise of blood supply to the lower pole ureter

57. POSTERIOR URETHRAL VALVE

58. POSTERIOR URETHRAL VALVE
Obstructive congenital defect caused by a malformation of the posterior urethra
Most common cause of lower urinary tract obstruction in male neonates
Incidence is 1 per 8,000 to 1 per 25,000 live births
Cause of renal insufficiency in approximately 10-15% of children undergoing renal transplant
1/3 of patients born with PUV progress to ESRD
Diagnosis is usually made before birth or at birth

59. Embryogenesis
The most caudal end of the Wolffian duct is absorbed into the primitive cloaca at the site of the future verumontanum in the posterior urethra
In normal healthy males, the remnants of this process are the posterior urethral folds, called plicae colliculi.
Histological studies 
PUVs are formed at approximately 4 weeks' gestation, as the Wolffian duct fuses with the developing cloaca
Degree of obstruction varies depending on the configuration of the obstructive membrane within the urethra
May present with severe pulmonary distress
Due to underdevelopment of the lung caused by oligohydramnios

62. Clinical Presentation
Poor fetal breathing movements
Small chest cavity
Abdominal mass (ascites)
Potter facies
Limb deformities (skin dimpling)
Indentation of the knees and elbows due to compression within the uterus

63. Ancillary Procedures Creatinine and BUN
obtained at least 24 hours after birth
provides a gross estimation of kidney function
Infant’s Glomerular filtration rate
VCUG (voiding cystourethrogram) or direct endoscopic visualization

64. Treatment Urethral catheter relief of urinary obstruction
Vesicostomy and then valve ablation
making a stoma in the urinary bladder, followed by closure of the stoma and valve ablation
Pyelostomy and then valve ablation
making a stoma in the pelvis of the kidney, followed by closure of the stoma and valve ablation
Primary (transurethral) Valve ablation
removal of the valves through urethra, without stoma

65. Complications
Incontinence
Infection
VUR
Progressive renal damage

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