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

* 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.

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.

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.

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

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

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

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

Calcium oxalate stones

Calcium phosphate stones

Uric acid stone

Cysteine stones

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

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.

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.

X- Ray showing radio opaque stone

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

* 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..

Hydronephrosis & Hydroureter

Hydronephrosis

Hydronephrosis

Hydronephrosis

Infected hydronephrosis (pyonephrosis)

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