1. Assistant professor of pathology
Obstructive Uropathy
Dr. Abdelaty Shawky
Assistant professor of pathology

2. * Causes of UT obstruction:
1. Urethral causes: phimosis – stricture - tumors.
2. Prostatic causes: BPH - cancer.
3. Bladder neck obstruction: functional, bilharziasis, stone, tumor.
4. Ureteric causes: bilharzial stricture, stone, tumors, pregnancy, retroperitoneal fibrosis.
5. Renal pelvis causes: stone, tumor.

3. Phimosis Means narrowing of the external urethral orifice.
a. Congenital: a condition where, in men, the foreskin cannot be fully retracted over the glans penis.
b. Acquired: secondary to inflammatory lesions.

4. Urinary calculi (stones)
* Types:
I. 1ry (metabolic) stones:
Calcium stones (calcium oxalate or phosphate).
Uric acid stone.
Cysteine stone.
II. 2ry (Infected) stone: (Struvite stone).
III. Compound stone.

5. I. 1ry (metabolic) stones
Cysteine stone
Uric acid stone
Ca oxalate/phosphate stone
cysteinuria
Hyperuricemia
hypercalcaemia
Etiology
rounded
Shape
soft
firm
hard
Consistency
smooth
spiny
Outer surface
yellow
Light brown
brown
Color

6. II. 2ry (infected) stone (struvite)
Urinary tract infection which precipitate magnesium and ammonia
Etiology
Rounded or stag horn
Shape
Friable
Consistency
Smooth
Outer surface
white
Color

7. III. Compound stone 1ry stone followed by urinary tract infection
Etiology
Rounded or stag horn stone
Shape
Variable
Consistency
Smooth
Outer surface
variable
Color

8. Stag horn stone: is the stone with branches formed within calyces and pelvis is termed stag horn-like.

9. Calcium oxalate stones

10. Calcium phosphate stones

11. Uric acid stone

12. Cysteine stones

13. Diagnosis of renal calculi
I. Clinical picture. II. Investigations.

14. I. Clinical Picture
Asymptomatic if the stone do not cause any obstruction.
Severe flank pain: colicky in nature (comes and goes in spasmodic waves). Pain in the back occurs when calculi produce an obstruction in the kidney or pain caused by peristaltic contractions of the ureter as it attempts to expel the stone
Flank pain referred to genitalia
Nausea, vomiting may mislead
Microhematuria if stone have rough surface.
The picture of acute renal colic is well described in textbooks of physical diagnosis. The mechanism for pain production is through the sudden obstruction of the kidney with stretching of the collecting system and renal capsule. It is the stretching of these structures that causes the pain. The pain is not the result of a foreign body on the mucosa of the ureter. In most cases sudden renal obstruction produces flank pain. It is not possible from the pain to predict what level the stone is at. The only time one can predict the stone’s location is when the patient begins to complain of symptoms of bladder irritation. When this occurs the stone is in the most distal portion of the ureter (intra-mural ureter) which produces some inflammation of the bladder neck and hence the bladder irritative symptoms.
The associated gi symptoms of nausea and vomiting may be pronounced and mislead you into thinking that the patient has a gi problem. Look for hematuria, most patients passing a stone will have at least microscopic hematuria.
Chronic stone disease may have little associated pain. Although there may be renal and ureteral obstruction present often this has been long standing and no longer produces the dramatic pain of acute obstruction. Often there will be chronic infection which resist attempts at cure.

15. II. Investigations
1. Urine analysis: hematuria, infection, type of crystals.
2. X - Ray: most of renal stones are radiopaque due to calcification except uric acid stones are radiolucent so not seen.
3. Ultrasounography: can show stones and hydronephrosis.
4. Intravenous pyelogram (IVP): will show delayed function, hydronephrosis and hydroureter.
The physical examination is very important and renal colic needs to be distinguished from non-renal causes of abdominal pain. Expect to see cva tenderness and the absence of signs of peritoneal irritation (i.e... rebound tenderness)
The Urine sediment will often have at least microscopic hematuria. The UA is very important to 1- firm up the diagnosis of renal stone 2- detect possible uti.
The KUB is helpful since only 5% of stones are radiolucent. Remember that stones may be obscured if they are overlying bone such as the sacrum. The IVU confirms the diagnosis and will show delayed function on the involved side with hydronephrosis and ureteral obstruction eventually reaching the point of the obstructing stone.

16. X- Ray showing radio opaque stone

18. Intravenous pyelogram (IVP) showing hydronephrosis and dilated calyx of the right kidney

19. * Complications of renal stones:
Migration → pain & obstruction.
Obstruction → hydroureter & hydronephrosis or calculus anuria.
Hematuria due to Injury of urinary mucosa.
Infection → cystitis → pyelonephritis, pyoureter, pyonephrosis.
Metaplasia (squamous metaplasia) → squamous cell carcinoma..

20. Hydronephrosis & Hydroureter

21. Hydronephrosis

22. Hydronephrosis

23. Hydronephrosis

24. Infected hydronephrosis (pyonephrosis)

25. Thanks