It is defined as aseptic dilatation of the pelvi-calyceal system of kidney due to partial or complete obstruction to the outflow of urine

Fig : Unlateral and Bilateral Hydronephrosis

Types Of Hydronephrosis
1. Unilateral hydronephrosis
2. Bilateral hydronephrosis
Causes Of Unilateral Hydronephrosis / Unilateral Ureteric Obstruction
A. Extramural obstruction
      1. Tumour from adjacent structures (Cervix, prostate, rectum, colon or caecum)
      2. Idiopathic retroperitoneal fibrosis
      3. Retrocaval ureter
B. Intramural obstruction
      1. Pelviureteric junction obstruction (Due to congenital narrowing / physiological narrowing)
      2. Ureterocele
      3. Congenital small ureteric orifice
      4. Inflammatory stricture of ureter
      5. Neoplasm of the ureter or bladder cancer involving the ureteric orifice
C. Intraluminal obstruction
      1. Stone in the pelvis or ureter
      2. Sloughed papilla in papillary necrosis
Causes Of bilateral Hydronephrosis
A. From lower urinary tract obstruction
      a. Congenital
            1. Posterior urethral valves
            2. Urethral atresia
      b. Acquired
            1. Benign enlargement of prostate
            2. Carcinoma of prostate
            3. Postoperative bladder neck scarring
            4. Urethral stricture
B. From upper urinary tract obstruction
            1. Idiopathic retroperitoneal fibrosis
C. From pregnancy
Management Of Hydronephrosis
A. Clinical features
      1. M : F ratio is 2 : 1
      2. Right side is commonly affected
      3. Patient may present with….
            Mild pain, dull aching loin pain
            Dragging / heaviness after intake of excess amount of fluid
            Enlarged palpable kidney
            Attack of acute renal colic may occur & no palpable swelling
            Intermittent hydronephrosis (Dietl’s crisis)
                  History of acute renal pain
                  Swelling in the loin
                  After the passage of large amount of urine, the swelling & pain disappears
B. Investigations
      1. Plain X-Ray in KUB region
      2. USG
      3. Excretion urography
      4. Isotope renography – Agent used : Diethylenetriaminepenta-acetic acid (DTPA)
      5. Retrograde pyelography
      6. Whitaker test (Differentiation of obstructive from non obstructive uropathy)
      7. BUN & serum creatinine
C. Treatment
      1. Symptomatic – Follow up by serial USG & operation is done if dilatation is increasing
      2. Specific treatment (Surgical)
            Nephrectomy : When renal paranchyma is hugely destroyed & other kidney is functioning
            Pyeloplasty : Reconstruction of the renal pelvis
            Endoscopic pyelolysis
Complications Of Hydronephrosis
1. Infection – Pyonephrosis
2. Urolithiasis
3. Secondary HTN
4. Traumatic rupture
5. Kidney damage
6. Kidney failure
Radiological Findings In Hydronephrosis
      Normal cupping of the calyces will be lost
On excretory urography
      Extrarenal pelvis is dilated
      Minor calyces lose their normal cupping and become ‘clubbed’.
      Soup bubble appearance


It is a condition that results from infection of a hydronephrosis where the kidney becomes a multilocular sac containing pus or purulent urine
It is a surgical emergency
Management Of Pyonephrosis
A. Clinical features
      Classical triad of….
            1. Anaemia
            2. Fever
            3. Swelling in the loin
B. Investigations
      1. Plain X-Ray abdomen
      2. USG
      3. Intravenous urogram
C. Treatment (It is a surgical emergency)
      1. Hospitalization of the patient
      2. Parenteral antbiotics are given immediately
      3. Drainage of the kidney
            Percutaneous nephrostomy
            Open nephrostomy
      4. Removal of stone, if present
      5. Nephrectomy
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