Hydronephrosis is the dilation of the renal pelvis and calyces caused by obstruction of urine flow from the kidney. It can be caused by issues in the ureter, bladder, or urethra that limit urine outflow. Unilateral hydronephrosis may cause dull flank pain while bilateral obstruction can lead to decreased urine output. Left untreated, hydronephrosis can damage kidney tissue and impair renal function. Diagnosis is made through imaging tests like intravenous pyelogram. Treatment focuses on resolving the underlying cause of obstruction.

1. HYDRONEPHROSIS

2. CONTENTS
Definition
Etiology
Pathology
Clinical features
Special investigations
Treatment
2

3. ORGANS OF THE RENAL
SYSTEM
• Kidneys
• Ureters
• Urinary bladder
• Urethra
3
Figure 23.1a

4. FUNCTIONS OF URINARY
SYSTEM
Regulate
•electrolytes (K+, Na+, etc)
•pH in blood
•blood pressure
•blood volume (removes excess fluid)
•Removing metabolic wastes
• Urea, uric acid, and creatinine
4

5. RELATIONSHIP OF THE KIDNEYS
TO VERTEBRA AND RIBS
They are retroperitoneal and
are located in the abdominal
cavity.
They are at the level of T12 to
L3, so they are at the costal
margin, and the floating ribs
protect them a little.
Even though they are
protected by thoracic ribs,
they are NOT in the thoracic
cavity because they are below
the diaphragm.

6. POSITION OF THE KIDNEYS WITH
IN THE POSTERIOR ABDOMINAL
WALL
6
Figure 23.2a

7. • The RENAL CAPSULE surrounds the
kidney, made of dense fibrous
connective tissue.
• A layer of adipose tissue surrounds
the capsule, called PARARENAL
FAT (ADIPOSE). It cushions and
protects.
• Around that is a connective tissue
layer called the RENAL FASCIA,
made of loose connective tissue. It
anchors the kidney to the
surrounding peritoneum and
abdominal wall. It is not very
strong; jumping up and down can
cause tearing.
7
STRUCTURES WITHIN THE KIDNEY

8. Vibration Platform Machine:
No longer used in the USA because it damages
kidneys!
8

9. These are still around in gyms in
other countries…beware! 9

10. • Renal cortex (most
superficial layer)
• Renal medulla
• Renal pyramids (drain into the
calyx)
• Renal pelvis
• Calyx (drains into hylus 
ureter)
Ureter
10

11. Aorta  renal artery 
segmental arteries 
interlobar arteries 
arcuate arteries (form
arcs)  interlobular
arteries
Interlobular vein 
arcuate vein 
interlobar veins 
segmental veins 
renal vein  inf. Vena
cava
11

12. Microscopic Anatomy of the
Kidneys
• Just like the functional unit of the lungs is the alveolus and the
functional unit of the liver is the lobule, the functional unit of
the kidney is the NEPHRON.
• Each kidney has about 1 million nephrons.
• Each one carries out all of the various functions of the kidneys.
12

13. • Glomerulus with a
capsule
• Proximal convoluted
tubule
• Loop of henle
• Descending limb
• Thick portion
• Thin portion
• Ascending limb
• Thick portion
• Thin portion
• Distal convoluted tubule
• Collecting duct 13
MICROSCOPIC ANATOMY

14. Position of Nephron in
Kidney
14
Figure 23.4a

15. Glomerulus of a Nephron
15

16. Nephron
16

17. HYDRONEPHROSIS
•Dilatation of renal
pelvis & calyces with
accompanying
destruction of the
kidney parenchyma
•Usually due to partial
obstruction to the
outflow of urine
17

18. 18
NORMAL KIDNEY HYDRONEPHROSIS

19. NORMAL INTRAVENOUS PYELOGRAM (IVP)19

20. INTRAVENOUS PYELOGRAM (IVP) SHOWING
HYDRONEPHROSIS
20

21. 21

22. •Normally, urine flows through the urinary
tract with minimal pressure.
•Obstruction in the urinary tract can build
the pressure
Enlargement of kidneys
•Kidney becomes bigger with urine that it
presses against the nearby organs
•Left untreated the kidney loses its function 22

23. ETIOLOGY
Primary or secondary
PRIMARY: When the no cause can be detectable the
condition called as idiopathic or primary hydronephrosis
SECONDARY: When there is definite definable cause
attribution hydronephrosis
Maybe unilateral or bilateral
23

24. PRIMARY HYDRONEPHROSIS:
•Primary hydronephrosis these are mostly encontered in
childrens and obstruction lies at pelviureteric junction or vesico
ureteric junction.
•Obstruction is regarded as being neuromuscular in majority of
cases.
• Imbalance between sympathetic and parasympathetic supply of
muscles due to defective coordination in muscular peristalsis
spasmodic segment of circular muscle particularly at pelviureteric
junction.
•Due to defect in muscular coordination obstruction to the
passage of urine develops to cause hydronephrosis
24

25. CAUSES OF UNILATERAL HYDORNEPHROSIS
•Maybe extramural, intramural
or Intraluminal
•Extramural:
• Pressure on the ureter by
loaded sigmoid colon,
gravid uterus, uterine &
ovarian tumors
• Involvement of the ureter
by malignant neoplasm
outside it e.g. carcinoma of
the cervix, uterus, colon,
rectum, prostate
• Aberrant renal vessels
• Idiopathic retroperitoneal
fibrosis 25

26. CAUSES OF UNILATERAL HYDORNEPHROSIS
•Maybe extramural, intramural or Intraluminal
•Intramural:
• Congenital stenosis or achalasia of the PUJ
• Ureterocele
• Stricture
• Neoplasm of ureter
26

27. CAUSES OF UNILATERAL HYDORNEPHROSIS
•Maybe extramural, intramural or Intraluminal
•Intraluminal:
• Calculus
• Congenital folds at the upper end of the ureter
27

28. CAUSES OF BILATERAL
HYDORNEPHROSIS
•Due to pathologies in the urethra or the urinary bladder
•Causes in the urethra:
• Pin – hole meatus
• Congenital valves
• BPH & carcinoma of prostate
• Stricture
• Carcinoma of cervix & uterus
28

29. CAUSES OF BILATERAL
HYDORNEPHROSIS
•Due to pathologies in the urethra or the urinary bladder
•Causes in the bladder:
• Calculus
• Neoplasms
• Sphincter dysfunction
29

30. 30

31. 31

32. 32

33. INTRINSIC CAUSES OF HYDRONEPHROSIS
Ureter
•Kidney stone. Likely the most common reason to have unilateral
hydronephrosis is a kidney stone that causes obstruction of the
ureter.
The stone gradually moves from the kidney into the bladder but
if it should act like a dam while in the ureter, urine will back up
and cause the kidney to swell. This would be classified as an
intrinsic obstruction.
•Blood clot
•Stricture or scarring
33

34. Bladder
•Bladder cancer
•Bladder stones
•Cystocele
•Bladder neck contracture
Urethra
•The inability to empty the bladder (urinary retention) for any
reason may cause bilateral hydronephrosis.
•Urethral stricture
•Urethral valves
34

35. EXTRINSIC CAUSES OF HYDRONEPHROSIS
Ureter
•Tumors or cancers that compress the ureter and prevent urine
flow. Examples include lymphoma and sarcoma, especially if they
are located in the retroperitoneum, where the kidneys and
ureters are located behind the sac that contains the bowel.
•Retroperitoneal fibrosis
•Ovarian vein syndrome
•Cancer of the cervix
•Cancer of the prostate
•Pregnancy
•Uterine prolapse
•Scarring due to radiation therapy
35

36. Urethra
•Prostate hypertrophy or swelling is a common cause of urinary
retention and subsequent hydronephrosis in males.
•Prostate cancer
36

37. FUNCTIONAL CAUSES OF HYDRONEPHROSIS
Bladder
•Neurogenic bladder or the inability of the bladder to function
properly occurs because of damage to the nerves that supply it.
This may occur in brain tumors, spinal cord injuries or
tumors, multiple sclerosis, and diabetes among other causes.
•Vesicoureteral reflux where urine flows backwards from the
bladder into the ureter. Prenatal hydronephrosis is an example,
though it may occur at any time in life
37

38. PATHOPHYSIOLOGY
•Dilatation of the renal pelvis & calyces
•Types of hydronephrosis:
• Pelvic type
• Renal type
• Pelvirenal type: most common type, both the
pelvis & calyces are equally dilated
38

39. 39

40. PATHOLOGY OF
HYDRONEPHROSIS
•The essential change is dilation of renal pelvis and calyces the
normal pelvis has average capacity of 7 to 10 ml of urine.
•The dilatation of renal pelvicalyceal system may contain 300-500
ml of urine.
•The calyces which show great dilatation are mostly idiopathic.
40

41. MACROSCOPIC CHANGES
• Pyramids of medulla of
kidney suffered
• Cortex of kidney
becomes involved
• The calyces are
blunted and
• Gradually they distend
to destroy the
substance of the
kidney.
• Gradually the cortex
thinned to a mere
shell. 41

42. MICROSCOPIC CHANGES
• In the early stage the
tubules are dilated
which gradually
becomes atrophied in
the later stage.
• The glomeruli remain
comparatively intact
and they appear more
in no. Due to
parenchymal atrophy
of kidney.
• After 3 weeks of
complete obstruction
the function of the
affected kidney
irreversibly damaged.
42

43. STAGES OF HYDRONEPHROSIS
•OPEN HYDRONEPHROSIS : In this condition the hydronephrosis
sac is openly communicated with the lower urinary tract as the
obstruction is incomplete.
•INTERMITTENT HYDRONEPHROSIS : Here the hydronephrotic
sac intermittently communicates with the lower urinary tract as
the obstruction is complete intermittently . dietls crisis.
•CLOSED HYDRONEPHROSIS : Hydronephrotic sac completely
closed off from lower urinary tract.
43

44. CLINICAL FEATURES
•May depend on unilateral, intermittent or bilateral
hydronephrosis
•UNILATERAL HYDRONEPHROSIS:
• Dull ache & sense of weight on the affected side of the loin
• Causes of the hydronephrosis
44

45. CLINICAL FEATURES OF
UNILATERAL
HYDRONEPHROSISF :M 2 :1
Rt side > Lt.Side
C/f due to cause :
•Renal colic and hematuria in calculus obstruction
•Types of presentation:
• Insiduous onset
•Acute colic
• Intermittent
45

46. Insiduous onset :unilateral dull aching loin pain
Pain aggravated by water intake and alcohol
Acute colic: acute renal coliky pain with no palpable swelling.
Intermittent :patient complain of acute pain,decrease urine
output and swelling in loin. Followed by polyuria , decrease renal
pain, disappearance of renal swelling.
46

47. ACUTE HYDRONEPHROSIS
•Symptoms from renal colic due to a kidney stone
begin with an acute onset of intense flank or back
pain radiating to the groin, associated
with nausea,
•vomiting, and
•sweating
•Colicky pain comes and goes and its intensity may
cause the person to writhe or roll around or pace
in pain.
•There may be blood seen in the urine.
47

48. CHRONIC
HYDRONEPHROSIS
•Chronic hydronephrosis develops over time and there may be
no specific symptoms.
•Tumors in the pelvis or bladder obstruction may develop silently
and the person may have symptoms of kidney failure
•These are often nonspecific and may include weakness,
malaise, chest pain, shortness of breath, leg swelling, nausea and
vomiting.
•If electrolyte abnormalities occur because the kidneys are
unable to regulate sodium, potassium, and calcium, there may be
heart rhythm disturbances and muscle spasms.
48

49. BILATERAL HYDRONEPHROSIS CLINICAL
FEATURES
CLINICAL FEATURES DUE TO CAUSE :
•Symptom of bladder outflow obstruction decrease urine output
•Fullness in lower abdomen intense desire but not able to pass
urine,
•Symptoms of hydronephrosis
•Dull aching loin pain swelling ( renal failure supervenes before
significant dilatation occurs. )
49

50. EVALUATION
Depending upon the situation and whether there is acute onset
of symptoms,
•Physical examination - tenderness in the flank or where the
kidneys are located.
•The bladder - distended when the abdomen is examined.
•PR for males shows the size of the prostate.
•Pelvic examination in females may be performed to evaluate the
uterus and ovaries.
50

51. •Urinalysis to look for blood, infection or abnormal cells
•Complete blood count (CBC) may reveal anemia or potential
infection
•Electrolyte analysis may be helpful in chronic hydronephrosis
since the kidneys are responsible for maintaining and balancing
their concentrations in the blood stream.
51

52. X RAY KUB
KUB X-rays (an X-ray that
shows the kidney, ureter,
and bladder) are used by
some urologists to
classify a kidney stone as
radiodense or
radiolucent and
may use KUB X-rays to
determine if the stone is
able to migrate down the
ureter into the bladder. 52

53. IVP
• IVP : Dilatation of
renal pelvis
decreasing concavity
and then flattening
of minor calyces with
dilatation of major
calyces a portion of
pelvis becomes more
dependant part
below the level of
PVJ
53

54. Special investigations
•Excretory urography
•Retrograde urography
•Ultrasound
54

55. 55

56. •CT scan of the abdomen can be performed to evaluate the
kidney anatomy and make the diagnosis of hydronephrosis.
•It also may allow look for the underlying cause including kidney
stones or structures that are compressing the urinary collecting
system.
56

57. PRINCIPLES OF TREATMENT
In adults, the aims of treatment are to:
•remove the build-up of urine and relieve the pressure on your
kidney(s)
•prevent permanent kidney damage
•treat the underlying cause
•Most people with hydronephrosis should have catheterisation to
drain the urine from their kidney(s). Depending on the underlying
cause, medication or surgery may be needed afterwards to correct
the problem.
•If the condition is severe or causing problems such as a urinary tract
infection (UTI), it may be treated soon after it is diagnosed
57

58. •The first stage in treating hydronephrosis is to drain the urine
out of the kidneys. This will help ease pain and prevent any
further damage to kidneys.
•A thin tube called a catheter may be inserted into your bladder
through urethra or through spc
58

59. 59

60. TREATMENT GOAL
• The goal of treatment for hydronephrosis is to restart the free
flow of urine from the kidney and decrease the swelling and
pressure that builds up and decreases kidney function.
• The initial care for the patient is aimed at minimizing pain and
preventing urinary tract infections.
• The timing of the procedure depends upon the underlying
cause of hydronephrosis and hydroureter and the associated
medical conditions that may be present.
• For example, patients with a kidney stone may be allowed 1-2
weeks to pass the stone with only supportive pain control if
urine flow is not completely blocked by the stone.
• If, however, the patient develops an infection or if they only
have one kidney, surgical intervention may be done
emergently to remove the stone. 60

61. For patients with urinary retention and an enlarged bladder as a
cause of hydronephrosis, bladder catheterization may be all that
is needed for initial treatment.
When a stent cannot be placed, an alternative is inserting a
percutaneous nephrostomy tube. A urologist or interventional
radiologist uses fluoroscopy to insert a tube through the flank
directly into the kidney to allow urine to drain.
61

62. Shock wave lithotripsy(SWL )
Shock wave lithotripsy(SWL or
extracorporeal shock wave
lithotripsy) is the most
common treatment for kidney
stones
Shock waves from outside the
body are targeted at a kidney
stone causing the stone to
fragment into tiny pieces that
are able to be passed out of
62

63. For patients with ureteral strictures or stones that are difficult to
remove, stent may be placed into the ureter that bypasses the
obstruction and allows urine to flow from the kidney.
Using a fiber optic scope inserted through the urethra into the
bladder, can visualize where the ureter enters and can thread the
stent through the ureter into the kidney pelvis bypassing any
obstruction.
63

64. Treating hydronephrosis in babies
Most babies diagnosed with hydronephrosis before they're born
(antenatal hydronephrosis) won't need any treatment because the
condition will improve before they're born or within a few months of
their birth.
Investgiations are done for babies like:
•an ultrasound scan
•a micturating cystourethrogram (MCUG) – where a thin tube is used to
pass a special type of liquid that shows up clearly on X-rays into
thebaby's bladder while a series of X-rays are taken
•a dimercaptosuccinic acid (DMSA) scan or MAG-3 scan – where the is
injected with a substance that shows up on a special device called a
gamma camera; the camera is then used to take pictures of child's
kidneys
In most children, hydronephrosis will get better as they get older.
If hydronephrosis doesn't get better by itself, your child may need to
keep taking antibiotics.
Occasionally, surgery may be recommended to treat the underlying
cause of the condition.
64

65. INDICATIONS OF OPERATIONS :
•Increasing renal pain increasing hydronephrosis
•When hydronephrosis is complicated by infection/parenchymal
damage.
PROCEDURES : Nephrectomy
•Plastic operations
•Endoscopic pyelolysis / endoscopic pyelotomy
•Endoscopic ballon dilatation
65

66. Principles of pyeloplasty
•To reduce the size of the renal pelvis
•Excision of the PUJ
•The ureter is attached to the most dependent part of the pelvis
66

67. 67extraperitoneal flank approach,
bed of the twelfth rib

68. 68

69. Treatment
•Secondary hydronephrosis: treatment of the
cause
•Primary hydronephrosis:
• Pyeloplasty:
• Anderson- Hynes
• Culp
• Foley
• Nephrectomy 69

70. PROCEDURES FOR PRIMARY
HYDRONEPHROSIS
•PRINCIPLES :
•To reduce the size of the renal pelvis
•To excise the PUJ as this may be the area of failure of muscular
coordination and
•To avoid subsequent stricture formation the ureter is attached
to the most dependant part of pelvis.
Anderson hynes pyeloplasty
•Culp pyeloplasty
•Foley pyeloplasty 70

71. 71

72. Marking stitches are placed on the renal pelvis superior to
the obstruction and the lateral aspect of the proximal
ureter below the level of the obstruction.
b The ureteropelvic junction tissue is then excised and an
anastomosis is created with fine interrupted or running
absorption sutures.
c The sutures are placed in a watertight manner over an
internal ureteral stent, which remains in situ.
ANDERSON HYNES PYELOPLASTY
72

73. 73
A spiral incision is made in the enlarged renal pelvis and
extended an equal distance into the ureter.
b | The tissue flap is turned down and stitched into the
adjacent ureter.
c | The flap is closed with fine interrupted or running
absorption sutures.

74. 74
a | The ureter is pulled with a stitch while a Y-shaped
incision is made in the renal pelvis and ureter.
b | A V-shaped flap is opened in the ureteropelvic junction
tissue.
c | The V-shaped flap is sutured to the apex of the ureteral
incision with fine interrupted or running absorption sutures.

75. 75

76. 76

77. COMPLICATIONS
• Development of a urinary tract infection (UTI).
• When the UTI is associated with a high fever, a kidney
infection is (pyelonephritis) is suspected. This is caused by
bacteria spreading from the bladder to the kidney and
invading the kidney tissue.
• If pyelonephritis is severe or not treated in a timely manner,
or if it affects both kidneys, complications such as
• permanent kidney damage (kidney scarring) can lead to
problems such as high blood pressure and sometimes kidney
failure.
77

78. ROBOT-ASSISTED
PYELOPLASTY
A robot-assisted pyeloplasty is a minimally invasive laparoscopic
procedure. With the use of a tiny camera, surgeons operate
using very thin instruments inserted into three or four small
incisions. Robot-assisted pyeloplasty removes an obstructed
section of the ureter and reattaches the healthy portion to the
kidney's drainage system.
Robotic surgery can offer a number of benefits as compared to
traditional (open) surgery, including:
•less discomfort after the operation
•smaller scars on the belly
•a shorter hospital stay—
usually 24 to 48 hours
•quicker recovery
•earlier return to full activities
78

79. 79

80. 80

81. 81

82. 82

83. 83