Hydronephrosis for students

Hydronephrosis

Lecture 51Dr Mohammad Manzoor Mashwani

Urinary Tract Obstruction (Obstructive Uropathy)

Hydronephrosis• Hydronephrosis is the term used to describe

dilation of the renal pelvis and calyces associated with

progressive atrophy of the

kidney due to obstruction to the outflow of urine.

Types of Obstruction

• SUDDEN • INSIDIOUS, • PARTIAL or • COMPLETE, • UNILATERAL or • BILATERAL;

Types of LesionsIt can be caused by lesions that are

• Intrinsic to the urinary tract or

•Extrinsic lesions that compress the ureter.

Obstructive lesions of the urinary tract

Types of Hydronephrosis• Primary Hydronephrosis• Secondary Hydronephrosis

Causes• 1. Congenital anomalies• 2. Urinary calculi • 3. Benign prostatic hypertrophy • 4. Tumors• 5. Inflammation • 6. Sloughed papillae or blood clots • 7. Pregnancy • 8. Uterine prolapse and cystocele • 9. Functional disorders

MorphologyWhen the obstruction is SUDDEN and COMPLETE,

GLOMERULAR FILTRATION IS REDUCED. • It leads to

• MILD DILATION OF THE PELVIS and CALYCES and sometimes to

• ATROPHY OF THE RENAL PARENCHYMA.

Morphology• When the obstruction is

• SUBTOTAL or INTERMITTENT, GLOMERULAR FILTRATION IS NOT SUPPRESSED, and PROGRESSIVE DILATION ENSUES.

• Depending on the level of urinary block,

• The dilation may affect

The bladder first, or

The ureter and then

The kidney.

The kidney may be slightly to massively

ENLARGED,

depending on the degree and the duration of the obstruction.

The earlier features are those of simple DILATION OF THE PELVIS AND CALYCES, but in addition there is often significant

INTERSTITIAL INFLAMMATION,

even in the absence of infection.

• In chronic cases the picture is one of

•CORTICAL TUBULAR ATROPHY with marked diffuse

INTERSTITIAL FIBROSIS.

• Progressive blunting of the apices of the pyramids occurs, and these eventually become

cupped.

•In far-advanced cases the kidney may become transformed into • A THIN-WALLED CYSTIC STRUCTURE

having a diameter of up to 15 to 20 cm

• with striking PARENCHYMAL ATROPHY,

• TOTAL OBLITERATION OF THE PYRAMIDS, and

• THINNING OF THE CORTEX.

Hydronephrosis of the kidney, with marked dilation of the pelvis and calyces and thinning of the renal parenchyma.

Clinical Features

I. Acute obstruction may provoke PAIN attributed to distention of the collecting system or renal capsule.

• Most of the early symptoms are produced

by the underlying CAUSE of the hydronephrosis.

Clinical features: Acute Obstruction

• Thus, calculi lodged in the URETERS

may give rise to RENAL COLIC, and

• PROSTATIC ENLARGEMENTS may give rise to BLADDER SYMPTOMS.

Clinical features II. Unilateral complete or Partial Hydronephrosis

• Unilateral complete or partial hydronephrosis may remain SILENT FOR LONG PERIODS, since the unaffected kidney can maintain adequate renal function.

• Sometimes its existence first becomes apparent in the course of

• INTRAVENOUS PYELOGRAPHY.

Clinical featuresUnilateral complete or Partial Hydronephrosis

• It is regrettable that this disease tends to

remain ASYMPTOMATIC, because in its early stages, perhaps the first few weeks,

• relief of obstruction leads to

reversion to normal function.

III. In bilateral partial obstruction the earliest manifestation is inability to concentrate the urine, reflected by

POLYURIA AND NOCTURIA.

• In bilateral partial obstruction :Some patients have • acquired distal tubular acidosis, • renal salt wasting, • secondary renal calculi, and • a typical picture of chronic tubulointerstitial

nephritis with scarring and atrophy of the papilla and medulla.

• Hypertension is common in such patients.

IV. Complete bilateral obstruction

• Complete bilateral obstruction results in

OLIGURIA or ANURIA and is

incompatible with survival unless

the obstruction is relieved.

IV. Complete bilateral obstruction

• Curiously, after relief of complete urinary tract obstruction,

Postobstructive diuresis occurs.

• This can often be massive, with the kidney excreting large amounts of urine that is rich in sodium chloride.