The document discusses hydronephrosis and pyonephrosis, detailing their definitions, causes, pathophysiology, clinical features, investigations, and treatment options. Hydronephrosis is characterized by the dilatation of kidney structures due to urinary obstruction, while pyonephrosis refers to the infection that follows hydronephrosis. Treatment varies based on the underlying cause and includes both medical management and surgical intervention when necessary.

1. HYDRONEPHROSIS
AND PYONEPHROSIS
Presented by:
Anish Dhakal
(Aryan)

2. CONTENTS
• Introduction
• Causes
• Pathophysiology
• Clinical Features
• Investigations
• Treatment

3. • Hydronephrosis is an aseptic dilatation of the kidney caused
by obstruction
• Dilation of renal pelvis and calyces associated with
progressive atrophy of the kidney
• Urine outflow obstruction
• Obstructive uropathy indicates impedance of urinary flow
anywhere along the urinary tract, upper or lower and
damage to the renal parenchyma due to obstruction at any
site

4. HYDRONEPHROSIS: CAUSES
Causes of Unilateral Ureteric Obstruction
Extramural obstruction:
Adjacent structures neoplasm like those of cervix, prostate,
rectum, colon or caecum
Idiopathic retroperitoneal fibrosis
Retrocaval ureter
Intramural obstruction:
Congenital stenosis, physiological narrowing of the pelviureteric
junction leading to pelviureteric junction obstruction
Ureterocele and congenital small ureteric orifice

5. CAUSES OF UNILATERAL URETERIC
OBSTRUCTION
Intramural obstruction:
 Inflammatory stricture following removal of ureteric calculus,
repair of a damaged ureter or tuberculous infection
 Neoplasm of the ureter or bladder cancer involving the ureteric
orifice
Intraluminal obstruction:
 Calculus in the pelvis or ureter
 Sloughed papilla in papillary necrosis (more commonly in
diabetics, analgesic abusers and sickle cell disease)

6. BILATERAL HYDRONEPHROSIS
It is commonly result of urethral obstruction.
Causes:
Congenital
 Posterior urethral valves
 Urethral atresia
Acquired
 Benign prostatic enlargement
 Carcinoma of the prostate
 Postoperative bladder neck scarring
 Urethral stricture
 Phimosis

8. PATHOPHYSIOLOGY
• Even with complete obstruction, glomerular filtration persists
for some time
• The filtrate diffuses back to the interstitium an perirenal
spaces
• Affected calyces and pelvis becomes dilated
• High pressure transmitted through collecting ducts:
Cortex: Renal atrophy
Medulla: Renal vasculature compression with diminished
inner medullar blood flow
• The kidney becomes a thin walled, lobulated, fluid filled
sac

9. PATHOPHYSIOLOGY
• Effective hydroureteronephrosis on renal function depends
on whether it is totally or partially obstructive and unilateral
or bilateral
• Effects of obstruction of the kidney are time dependent.
Within several hours, changes are evident but:
1–2 week:glomerular destruction, tubular atrophy,
and interstitial fibrosis occur
By 6–8 week: irreversible damage occurs

11. • Early stage: Elongation and dilatation of ureters due to mild obstruction
• Later stage: Further dilatation and elongation with kinking of the ureter, fibrous
band causes further kinking

12. CLINICAL FEATURES
Unilateral Hydronephrosis ( commonly by idiopathic
pelvicureteric junction obstruction or calculus)
• More common in women and on right side
• May remain silent for long periods, being apparent in course of
imaging studies (about 3% of population)
• Mild pain or dull aching in loin (dragging heaviness worsened by
excessive fluid intake)
• Kidney may be palpable
• Intermittent Hydronephrosis (Dietl’s crisis)

13. CLINICAL FEATURES
Bilateral Hydronephrosis:
 Loin pain
 Features of bladder outlet obstruction: Polyuria, Nocturia,
Dysuria, Hesitancy
 Kidneys usually not palpable
 Inability to concentrate urine which may be associated with
distal tubular acidosis, chronic tubulointerstitial nephritis, renal
and renal salt wasting

14. CLINICAL FEATURES
• Complete Bilateral Obstruction:
Rapid onset oliguria or anuria that is incompatible with
survival until obstruction is relieved. After relief, post
obstructive diuresis with large amount of sodium chloride
• Ureters and pelvis dilatation in pregnancy:
Up to 20th week .Back to normal within 12 weeks of delivery
Effect of high progesterone on smooth muscles

15. POSSIBLE EXAMINATION
FINDINGS
• General condition: pain or localized symptoms
• Abdominal, flank, or pelvic mass
• Flank tenderness can occur along with acute obstruction
and with calculi or infection
• Vaginal exam– Ureteral prolapse
• Digital rectal exam– Enlarged prostate, nodularity suggestive
of prostate cancer

16. INVESTIGATIONS
• Ultrasound scanning:
least invasive, regularly used for pelviureteric junction
obstruction
• Intravenous Pyelogram:
Significant function in obstructed kidney
Contrast fills the obstructed system down to blockage
Can take follow up films 36 hours after the injection of
contrast

17. INVESTIGATIONS
Isotope renography
 Best to confirm obstructive dilatation of collecting system
 Technetium 99m-labelled DTPA (diethylenetriaminepenta-
acetic acid or MAG-3) injected intravenously and tracked
using gamma camera
 99mTc-DTPA stays in renal pelvis in obstructed site

18. Isotope renogram series shows a late accumulation and
persistence of radioactivity in the left kidney

19. INVESTIGATIONS
Whitaker test
 Percutaneous puncture made in kidney, fluid is infused at
constant rate with monitoring intrapelvic pressure,
 Abnormal rise in intrapelvic pressure confirms obstruction
Retrograde Pyelography
 Confirms site of obstruction
 Done immediately before corrective surgery

21. TREATMENT
• Hydronephrosis is not a specific diagnosis but a finding or
sign
• Management is highly dependent on underlying condition
and the timing (acute vs. chronic)
• Urgent decompression is needed with:
– Severe pain
– Active urinary tract infection and acute kidney insufficiency
– Retrograde ureteral stent or percutaneous
nephrostomy can provide equally effective drainage

22. MEDICAL THERAPY
• Patients with infection and hydronephrosis require antibiotic
therapy and drainage
• Renal failure and electrolyte abnormalities should be
corrected in conjunction with drainage
• Along with these, catheter drainage may be required as well

23. TREATMENT
• Indications for surgery:
Bouts of renal pain
Increasing Hydronephrosis
Evidence of parenchymal damage and infection
• Mild cases followed by serial ultrasound scans and operated
upon if dilatation is increasing
• Nephrectomy considered only when kidney largely
destroyed

24. ANDERSONS-HYNES
PYELOPLASTY
• Upper third of ureter and renal pelvis is mobilized
• Renal vein can be divided but artery should be preserved
• Anastomosis formed in front of artery
• A nephrostomy tube or ureteric stent protects the
anastomosis
• Laparoscopic pyeloplasty, a minimal access procedure is
becoming increasingly popular

26. ENDOSCOPIC
PYELOPLASTY
• Disruption of pelviureteric junction by a balloon passed up
the ureter and distended under radiographic control
• Long term efficacy still need to be proved

27. PYONEPHROSIS

28. PYONEPHROSIS
• Greek (Pyon + Nephros)
• Infection following:
1. Hydronephrosis
2. Acute pyelonephritis
3. Renal calculus disease
Kidney becomes multilocular sac containing pus or
purulent urine

29. CLINICAL FEATURES
• Triad of
1. Anaemia
2. Fever
3. Loin swelling
• Symptoms of cystitis (burning sensation, persistent urge to
urinate, increased frequency, haematuria, pelvic discomfort,
fever)
• Infected Hydronephrosis: Large swelling, high grade fever
with rigors

30. INVESTIGATIONS
• May reveal calculus (complication: most common cause)
• Dilatation of pus filled collecting system

31. TREATMENT
• Surgical emergency due to high risk of permanent renal
damage and lethal septicaemia
• Parenteral antibiotics along with kidney drain
• Percutaneous nephrostomy, if pus is too thick open
nephrostomy is considered
• Nephrectomy is appropriate if kidney is totally destroyed
and the contralateral side kidney function is good

32. REFERENCES:
1) Smith and Tanagho, General Urology, 18th
Edition
2) Norman S. Williams et al, Bailey & Love’s
Short Practice of Surgery, 26th Edition
3) Gomella, Leonard G, 5 Minute Urology
Consult, 3rd Edition