Embryology Course, Second year, Faculty of Medicine, Damascus University

1. Urinary System Anomalies
www.marwanalhalabi.com
Marwan Alhalabi
Professor of Reproductive Medicine and Infertility,
Damascus University
Head of Assisted Reproduction Unit, Orient Hospital
President of Middle East Fertility Society
Past President of Syrian Society of Obstetricians and Gynecologists

2. Anomalies
of
Kidney

3. Anomalies of Kidney & Ureter
Anomalies in number:
1. Bilateral renal agenesis.
2. unilateral renal agenesis.
3. Supernumerary kidney.
Anomalies in structure
1. ARPKD
2. ADPKD
Anomalies in size
1. Hypoplasia
2. Dysplasia
Anomalies in rotation
1. Ventral
2. Dorsal
3. Lateral
Anomalies in ascend
1. Renal ectopia
2. Crossed renal ectopia
without or with fusion.

4. • Complete absence of the kidneys and ureters :
• Prenatal:
-Oligohydroamnios
-US
• postnatal
-Potter,s facial appearance
-Pulmonary abnormalities
-Often a single umbilical artery
• May be caused by failure of formation of either ureteric bud or
nephrogenic blastoma
• It is incompatible with life
Bilateral Renal Agenesis

5. Potter,s facial appearance

6. Potter,s facial appearance

7. • Absence of one kidney and ureter.
• Occurs more frequently than
bilateral renal agenesis.
• Compatible with life if the solitary
kidney is intact.
Unilateral Renal Agenesis

8. 8
Renal Agenesis

9. • Discovered
accidentally.
• Palpable mass at the
site of the extra
kidney
Supernumerary kidney

10. • Polycystic kidney
disease-infantile
type (ARPKD).
• Polycystic kidney
disease-adult
type (ADPKD).
Anomalies in Structure

12. • Autosomal dominant.
• More common than the
infantile type.
• Gradual onset.
• Most of cases are
identified between the
age of 30 and 50 years.
Polycystic Kidney disease-adult Type (ADPKD)

13. • Features:
- Renal mass
- Flank pain
- Hematuria
- UTI
- Later renal insufficiency
- Symptomatic treatment
- Later dialysis
Polycystic Kidney disease-adult Type (ADPKD)

14. • Autosomal recessive.
• Very rare.
• Small cysts representing
generalized dilatation of the
collecting tubules.
• The earlier the age, the more
severe the disease and the worse
the prognosis
Polycystic Kidney disease- Infantile Type
(ARPKD).

15. Features.
• Bilateral.
• Flank pain, renal mass, pulmonary hypoplasia, oliguria,
hypertension.
• If evident at birth, the usual clinical course is death within
the first 2 month.
• If later, renal failure and hypertension occur more slowly.
Polycystic Kidney disease- Infantile Type
(ARPKD).

16. 1. Renal hypoplasia
the term hypoplasia restricted to kidneys that have less
than the normal number of calyces and nephrons
2. Renal dysplasia
kidneys that have abnormal nephron structure (immature
or primitive glomeruli, nephron precursors) and number.
Anomalies in Size

17. • Congenitally small kidney.
• Contains a small numbers of normal
nephrons.
• Renal function is normal in
proportion to the mass of the
kidney.
May be:
• Unilateral.
• Bilateral.
Renal Hypoplasia

18. • Contains focal, diffuse or segmentally arranged primitive
structures.
• Specifically primitive ducts.
• A result of abnormal metanephric differentiation.
• All or only part of the kidney may be affected.
• The kidney may be abnormal in size or small.
Renal Dysplasia

19. • Cysts of various type may be present (cystic dysplasia).
• The entire kidney may be dysplastic with predominance of
cysts (multicystic dysplastic kidney).
Renal Dysplasia

20. • Failure of rotation during ascend to
renal fossa.
• Renal pelvis varies in position from
medial to other degree of
malrotation.
-Ventral position.
-Ventromedial position.
-Dorsal position.
-Lateral position.
Anomalies of Rotation

22. Renal ectopia
• The mature kidney fails to reach its normal location in the renal fossa
Positions :
• pelvic, iliac, abdominal, thoracic,
• Contra lateral = crossed
• Renal pelvis is located anteriorly different from renal ptosis
Anomalies of Ascend

23. Anomalies of Ascend

24. • Crossed ectopia with and
without fusion.
• Sigmoid or S-shaped kidney.
• Lump or cake kidney.
• Horse-shoe kidney.
Anomalies of Forms and Fusions

25. Anomalies of Forms and Fusions

26. Anomalies of Forms and Fusions

27. Anomalies of Forms and Fusions

28. due to failure of ascent.
Pelvic kidney

29. Pelvic kidney

30. Horse shoe kidney:
due to fusion between lower ends of both kidneys. Ascent is
arrested at level of L3 vertebra.

31. Horse shoe kidney:

32. Horse shoe kidney:

33. Horse shoe kidney:
33

34. Due to fusion of the upper and lower poles
Rosette kidney:

35. Discoid Kidney

36. Persistence of fetal lobulation
The surface of the kidney shows lobulations

38. Ectopic Kidney

39. Ectopic Kidney

40. Aberrant renal artery:

41. Accessory renal vessels

42. Accessory renal
vessels

43. Ureter
Anomalies

44. A- Ureteral duplication.
1. Complete (ectopic ureter).
2. Incomplete.
B- Pelvi-ureteric junction obstruction (PUJ).
C- Retrocaval ureter.
Anomalies of the Ureter

45. • Complete duplication:
2 separate pelves,
2 ureter,2 orifices.
• Two ureteric buds grows
from the mesonephric duct
towards the metanephric
mesenchyme.
Ureteral Duplication

46. Ectopic ureter is liable
to / associated with :
• Reflux
• Stenosis
• Incontinence (only in
female).
• Ureterocoele
Complete duplication
Ectopic ureter

47. Incomplete duplication:
the two ureters join prior
to entry into the bladder
Incomplete duplication

48. • Stenosis
• Aberrant vessels
• Prenatal . US
• Postnatal
• Palpable kid
• Radioisotope
Pelvi-ureteric junction obstruction (PUJ)

49. • The course of the ureter
is behind the inferior
vena cava.
Retrocaval Ureter

51. Urinary
Bladder Anomalies

52. Abnormality in:
1. Development of
bladder musculature
and.,
2. Development of
musculature of the
anterior abdominal
wall
Bladder extrophy

53. • Complete: accompanied by
wide separation pelvic
bones, epispadius,
rudimentary penis and
scrotum in boys and cleft
clitoris in girls.
• Incomplete: The defects
are only in the abdominal
and bladder wall.
Bladder extrophy

54. Extrophy of Bladder

55. • Deficient musculature
of the anterior
abdominal wall.
Brunne Belly Syndrome.

56. • Uretherorectal fistula
• Coloacal malformation
• Rectovaginal fistula
Urinary Fistula

57. Urinary Fistula

58. • Urachal diverticulum.
• Urachal sinus.
• Urachal fistula.
• Urachal cyst.
Urachal Anomalies

59. 59
Urachal Anomalies

60. Urachus
Abnormalities
60

61. Urethra
Anomalies

62. 1) Posterior urethral valve.
2) Meatal stenosis.
3) Phymosis.
4) Hypospadias.
5) Epispadias.
Anomalies of the Urethra

63. • Exaggerated folds of the posterior
urethra causing obstruction of the
urine flow.
Features:
• Obstructive uropathy.
• Bilateral hydronephrosis.
• Diagnosed by voiding
cystourethrogram (MCU).
Posterior Urethral Valves

64. • Also pinhole meatus,
Features:
• Obetructive uropathy
• Bilateral
hydronephrosis.
Meatal Stenosis

65. • Narrowing of the prepuce
(voreskin).
Features:
• Obetructive uropathy
• Pus discharge.
• Bilateral hydronephrosis.
Phymosis

66. Phymosis

67. • Abnormal site of external
urethral meatus (ventral).
• Associated with chordee in
most of the cases.
Types:
glanular, coronal,
subcoronal, penile, peno-
scrotal, scrotal, perineal.
Hypospadias

68. Hypospadias

69. Dorsal location of
the external meatus
of the urethral.
Types:
• Complete.
• Penile.
Epispadias

70. Epispadias

71. Acknowledgement

72. 72
Thank you

75. Renal Agenesis
• Renal Agenesis (absence):
Can be unilateral or
bilateral
• Renal agenesis results
when the ureteric buds do
not develop or the
primordia (stalks of buds)
of the ureters degenerate.
• Failure of the ureteric buds
to penetrate the
metanephrogenic blastema
results in failure of kidney
development

76. Unilateral Renal Agenesis
• Unilateral renal agenesis (absence)
occurs approximately once in every 1000
neonates.
• Males are affected more often than
females and the left kidney is usually the
one that is absent.
• Unilateral renal agenesis often causes no
symptoms and is usually not discovered
during infancy because the other kidney
usually undergoes compensatory
hypertrophy and performs the function
of the missing kidney.
• Unilateral renal agenesis should be
suspected in infants with a single
umbilical artery

77. Bilateral renal agenesis
• Bilateral renal agenesis is associated with oligohydramnios
(small amount of amniotic fluid) because little or no urine is
excreted into the amniotic cavity.
• This condition occurs approximately once in 3000 births, and
is incompatible with postnatal life.
• Infants with bilateral renal agenesis usually die shortly after
birth.

78. Malrotated Kidney
• If a kidney fails to
rotate, the hilum faces
anteriorly; that is, the
fetal kidney retains its
embryonic position
• Abnormal rotation of
the kidneys is often
associated with ectopic
kidneys.

79. Ectopic Kidneys
• One or both kidneys may
be in an abnormal
position.
• Most ectopic kidneys are
located in the pelvis, but
some lie in the inferior
part of the abdomen.
• Pelvic kidneys and other
forms of ectopia result
from failure of the kidneys
to ascend.

81. Horseshoe Kidney
• In 0.2% of the population, the poles of the
kidneys are fused; usually it is the inferior
poles that fuse.
• The large U-shaped kidney usually lies in the
pubic region.
• Normal ascent of the fused kidneys is
prevented because they are held down by
the root of the inferior mesenteric artery.
• A horseshoe kidney usually produces no
symptoms because its collecting system
develops normally and the ureters enter the
bladder.
• Approximately 7% of persons with Turner
syndrome have horseshoe kidneys.

82. Duplications of Urinary Tract
• Duplications of the
abdominal part of the
ureter and the renal
pelvis are common.
• These defects result
from abnormal division
of the ureteric bud.

83. • A supernumerary kidney with its own ureter, which is rare,
probably results from the formation of two ureteric buds.

84. Ectopic Ureter
• An ectopic ureter does not enter the urinary bladder.
• In males, the ureter usually opens into the neck of the bladder or the
prostatic part of the urethra. They may also enter the ductus deferens,
prostatic utricle, or seminal gland.
• In females, the ureter opens into the neck of the bladder, or the urethra,
vagina, or vestibule of vagina.
• Incontinence is the common complaint resulting from an ectopic ureter
because the urine flowing from the orifice does not enter the bladder;
instead it continually dribbles from the urethra in males and the urethra
and/or vagina in females.

85. Cystic Kidney Diseases
• In autosomal recessive polycystic kidney disease both kidneys
contain many small which result in renal insufficiency.
• Death of the infant usually occurs shortly after birth.
• Multicystic dysplastic kidney disease results from
dysmorphology during development of the renal system.
• In this kidney disease, fewer cysts are seen than in autosomal
recessive polycystic kidney disease and they range in size
from a few millimeters to many centimeters in the same
kidney.
• The cystic structures are wide dilations of parts of the
otherwise continuous nephrons, particularly the nephron
loops (of Henle).

86. URACHAL ANOMALIES
• In infants, a remnant of the urachal lumen may persist in the
inferior part of the urachus.
• In approximately 50% of cases, the lumen is continuous with
the cavity of the bladder.
• Remnants of the epithelial lining of the urachus may give rise
to urachal cysts.
• The inferior end of the urachus may dilate to form a urachal
sinus that opens into the bladder. The lumen in the superior
part of the urachus may also remain patent and form a urachal
sinus that opens at the umbilicus.
• Very rarely the entire urachus remains patent and forms a
urachal fistula that allows urine to escape from its umbilical
orifice

88. CONGENITAL MEGACYSTIS
• A pathologically large urinary bladder—megacystis or
megalocystis—may result from a congenital disorder
of the ureteric bud, which may be associated with
dilation of the renal pelvis.
• Many infants die from this disorder or suffer from
renal failure in early childhood.

89. EXSTROPHY OF BLADDER
• A deficiency of the anterior abdominal wall, is caused by incomplete
median closure of the inferior part of the wall.
• The defect involves both the abdominal wall and the anterior wall of the
urinary bladder; it results from failure of mesoderm to migrate between
the ectoderm and endoderm of the abdominal wall.
• As a result, the inferior parts of the rectus muscles are absent and the
external and internal oblique and the transversus abdominus muscles are
deficient.

90. EXSTROPHY OF BLADDER
• This rare birth defect occurs approximately once in every
10,000 to 40,000 births.
• Exstrophy (eversion) of the bladder usually occurs in
males. Exposure and protrusion of the mucosal surface of
the anterior wall of the bladder characterize this defect.
• The trigone of the bladder and the ureteric orifices are
exposed, and urine dribbles from the everted bladder.
• Epispadias (urethra opens on dorsum of penis) and wide
separation of the pubic bones are associated with
complete exstrophy of the bladder.

91. • Ectopy and hypoplasia associated with
facial maldevelopment
• Ectopy , malrotation and renal agenesis
associated with scoliosis and kyphosis
AGENESIS
• Rare less than 400 cases
• Bilateral … 50%... incompatible with life
• Unilateral ….compatible with life
• contralateral kidney hypertrophied
• Oligohydromnios
• Defect: ureteric bud fail to develop or
• fail to reach metanephric tissue
• Diagnosis: …ultrasound….CT sca
…cystoscopy.. Ureteric oriffice not
seenComplications… infection, stone,
HDN
CONGENITAL ANOMALIES OF KIDNEY

92. Renal Ectopia / pelvic kidneys
§ Kidney Doesn't ascend,
formed near pelvic brim
§ Usually asymptomatic
§ Present with pain or mass
which one may tempt to
remove as unexplained
pelvic mass
§ May be source of stone,
infection
§ Liable to trauma
§ TREATMENT: Treat the
complication
92

93. RENAL FUSION
Horse shoe kidney (Most common)• Lower poles fused in mid line in
front of 4th lumber vertebra
– ascent impeded by
inferior mesenteric artery
• Symptoms /signs.
usually asypmtomatic ,
flank Pain, hematuria, fever
• Exam : fixed mass below
umbilicus
• Diagnosis: U/S
IVU . Pelvis on anterior surface
• complications: Liable to disease
• angulated ureters + PUJ obstructionà urinary stasis à stones, infection &
obstruction àCRF.
93

94. • Treatment
• Asymptomatic = no treatment
• Mild sypmtoms = treat accordingly
• PUJ or ureteric obstruction, recurrent infections
• Stones
à surgery (pyelolithotomy + /-reconstruction)
• ISTHEMECTOMY with straightening of ureters
– less commonly done.
94

95. Pacake / Discoid Kidney :
-Bilateral fused pelvic kidneys ,
usually near the aortic
bifurcation
Crossed Renal Ectopia :
-Both kidneys are found in the same
side
-In 85-90 %of cases , the ectopic
kidney will be fused to the other side
-The upper pole of the ectopic kidney
is usually fused to the lower pole of
the other kidney , although fusion
may occur anywhere

96. Adult Polycystic kidneys
• Hereditary – autosomal dominant
• 95% bilateral
• Not manifested before 40
• Kidneys enlarged, studded with cysts
• Unyeilding capsule compresses
renal parenchyma causing atrophy
• Liver,lungs and pancreas may be affected
• CAUSE: defect in development of tubules.
• Cyst contents: Amber color fluid but
may be hemorrhagic
96

97. Signs / symptoms:
ú Loin pain- weight dragging upon peddicle or capsule
stretch, hemorhage in cyst, stone
ú abdominal mass- confused with cystic tumor
ú hematuria- cyst rupture in pelvis,moderate,
episodic.
ú hypertention, infection, & uremia/CRF.
ú Nonspecific symptoms: anorexia, headache, vague
abdominal discomfort, àvomiting, drowsiness,
anemia.
LABS:
Urine R/E.. Pyuria, microscopic hematuria
Deranged RFT’s, anemia
XRAYS: enlarged renal shadows > 16cm
bizarre calyceal system( spider deformity)
97

98. Polycystic kidneys
• US and CT:
• cysts in kidneys,liver, spleen and pancreas
• Blood & debris – cystic adenocarcinoma
• FNA- cytology – differentiates
• IVU
• Enlarged renal shadow,
• Renal pelvis – compressed & elongated
• Calyces – narrow, stretched over cysts ( spider legs / bell shaped)
COMPLICATIONS:
infection of cyst , pyelonephritis, hematuria
98

99. Polycystic kidneys
• Nephrologist :
• BP control, infection,anemia, disturbances of Ca metabolism, low
protein diet to delay need for DIALYSIS
• Urologist:
• Surgical / laproscopic deroofing of cysts ( Rovsing’s operation)
• Relieves pain & pressure à saving kidneys
• Renal transplant/ pretransplant bilateral native kidneys nephrectomy
99

100. solitary / Simple (acquired) renal cysts
• Common, may be multiple ( not always 1 )
• Incidentally found– no treatment needed
• Rarely symptomatic; pain- stretch, bleed in
cyst, infection,mass abdomen
• pelvic cyst at hilum presses PUJ à obs
• IVU: filling defect.
• US, CT :smooth, homogeneous content
• D/D: hydatid cyst, cystic
adenocarcinoma , renal cortical
abscess, HDN
• Percuteneous FNA Cytology
• Treatment… treat complications, in severe
cases cyst excision.
100

101. Infantile polycystic kidneys
• Rare
• Inheritance- autosomal recessive
• Enlarged kidneys – may obstruct labour, Many stillborn
• Die of renal failure in in early childhood
101

102. Multicystic kidney
• Mostly unilateral
• Non heriditary
• Presents as nonfunctioning irregular mass
• Diagnosis: U/S , IVU
• Exploration & removal is treatment of chioce
• DD: wilm’s, neuroblastoma, congenital hydronephrosis
102

104. Abnormalities of renal pelvis and ureter
• Most common, harmless, asymptomatic
• DUPLICATION OF RENAL PELVIS
• Common, usually unilateral – left
• Upper pelvis – small, drains upper calyx
• Asymptomatic no treatnment
• If one moity severly damaged – partial
nephrectomy
104

105. DUPLICATION OF URETER
Often join before reaching bladder,
suffer obstruction ( esp from
stones) & reflux
May open independently, ureter
from upper moity opens distal and
medial to its fellow.
Upper ureter suffers ureterocele.
Lower ureter suffers VUR
Infection, calculus formation, PUJ
obst and VUR, ectopic opening
105

107. Ectopic uretric opening
• Female – into urethra below sphincter on vagina = incotinence since childhood with
desire and passage of urine normally as well.
• IVU and cystoscopy
• Male.continent as opening is above sphincter
• Opening in trigone apex, post. Urethra, seminal vesical or ejaculatory duct – functionally
abnormal, infection common
• Treatment:
• Frequently ectopic ureter drains hydronephrotic, chronically infected kidney --- best excised
- nephrectomy
• Incontinence can be cured and renal function preserved by implanting ureter into bladder (
tunneling) or joining its fellow. (URETERO-NEOCYSTOSTOMY, URETERO-URETEROSTOMY)
107

109. CONGENITAL MEGA URETER
• Uncommon, bilateral
• FUNCTIONAL obstruction at
lower end à dilatation &
infection
• Ureteric orifices normal,
ureteric cath passes easily
• Reflux not feature till opened
endoscopically
• Treatment: refashioning and
tunneled reimplant
109

110. Aberrant vessels
-As the kidney ascends during
embryologic development , it
derives its blood supply from
the aorta at successively higher
levels with regression of the
lower level vessels
-If the lower level vessels persist ,
aberrant renal arteries will be
present
-Aberrant vessels can compress
the ureter anywhere along its
course , giving rise to
obstruction
-With color Doppler , aberrant
vessels may be seen crossing the
ureter at the level of ureteric
obstruction

111. POST (retro) CAVAL URETER
• Right ureter passes
behind
IVC instead of lying to the
right of it (laterally)
• If causing obstruction, can
be devided and joined in
front of cava – long
oblique anastomosis
111

112. URETEROCELE
• Cystic enlargement of
intramural portion of ureter
• Thought to result from
congenital atresia of ureteric
orifice
• Though present since
childhood, unrecognised till
adulthood
• More common in female,
cause BOO by obstructing /
prolapsing into internal
urinary meatus. May even
prolapse out of urethra
112

113. • Adder head on IVU
• Cyst wall composed of
urothelium only
• confirmed on cystoscopy
• Translucent cyst, enlarging and
collapsing as urine flows
• Treatment avoided unless
symptoms of infection / stone
• Endoscopic diathermy
incision / deroofing
• Postoperative MCUG to see
VUR
• Ureteral reimplant
• Sever hydronephrosis,
pyonephrosisà nephrectomy
113

114. ureterocele

115. EXSTROPHY OF BLADDER
• 3.3 per 100,000 births.
• Male to female 1.5:1ratio.
• incomplete median closure of the inferior part of the wall.
• the inferior parts of the rectus muscles is absent and the external and
internal oblique and the transversus abdominus muscles are
deficient.
Signs and symptoms
Exposure and protrusion of the mucosal surface of the anterior wall of
the bladder characterize this defect.
• The trigone of the bladder and the ureteric orifices are exposed, and
urine dribbles from the everted bladder.
• Epispadias
• Anus and vagina anteriorly located.
• UTI and HDN common

116. Treatment
• Sacral osteotomy with bladder closure.
• Anti ureteral reflux procedure and bladder
neck reconstruction
• Epispadias correction

117. Bladder Diverticula
-Outpouchings from the bladder wall, whereby mucosa herniates through the bladder
wall
-solitary or multiple in nature and can vary considerably in size
-May be congenital (primary) or acquired (secondary)
-A Hutch diverticulum is a congenital bladder diverticulum, seen at vesicoureteric
junction
Usually asymptomatic but can cause bladder outlet obstruction and UTI
-Treatment: symptomatic
• MCUG showing bladder diverticula

118. Urachal anomalies
-Normally, the urachus closes in the last half of fetal life
-There are 4 types of congenital urachal anomalies :
a) Patent urachus (50 %)
b) Urachal cyst (30 %), forms if the urachus closes at the umbilical and
bladder ends but remains patent in between, the cyst is usually
situated in the lower one third of the urachus
c) Urachal sinus (15 %), forms when the urachus closes at the bladder
end but remains patent at the umbilicus
d) Urachal diverticulum (5 %), forms if the urachus closes at the
umbilical end but remains patent at the bladder
-There is 2:1 predominance in males
Treatment:
-- Excision
-- Radical excision if evidence of adenocarcinoma .