CHAPTER 16 Urology

Congenital disorders of the urinary tract

Kidney and ureter

Congenital absence of one kidney

Bladder

Urachal abnormalities

Defects may result from the primitive urachal connections between bladder and umbilicus. If the tract persists, urine may discharge from the umbilicus. An urachal cyst may occur if part of the urachus persists but is closed off above and below. Infection may occur in an urachal cyst. Treatment is by excision.

Urethra

The urethra may terminate on the ventral aspect of the penis (hypospadias) or on its dorsal aspect (epispadias). Hypospadias may result in difficulty with intercourse. Plastic reconstruction of the urethra may be required. Epispadias is rare and more disabling and difficult to correct than hypospadias. It may be associated with incontinence. Plastic reconstruction or urinary diversions are possible treatments. In the female, the urethra may open on to the anterior vaginal wall.

Urethral valves may occur in the posterior urethra. The condition is rare, occurring with an incidence of 1:5000, 50% of cases occurring under 1 year of age. They cause dilatation of the prostatic urethra, bladder, ureters and pelvis. It is often diagnosed on prenatal USS. Rarely, there may be uraemia with palpable bladder and kidneys at birth. Milder cases present later in childhood with difficulty in voiding, recurrent UTIs and uraemia. Treatment is by transurethral resection of the valves. With early presentation the prognosis is good. With extensive renal damage, dialysis and transplantation may be required.

Haematuria

Haematuria is the passage of red blood cells in the urine. This may vary from a few red cells detected on ‘stix’ testing to the passage of frank blood. Haematuria may be noted at the beginning of micturition, throughout micturition or at the end of micturition. Care must be taken to avoid menstrual bleeding being mistaken for haematuria. Other causes of red urine include excessive beetroot ingestion, rifampicin, porphyria, haemoglobinuria and myoglobinuria. (For causes of haematuria → Table 16.1.)

TABLE 16.1 Causes of haematuria

Kidney	Glomerular disease
	Polycystic kidneys
	Carcinoma
	Stone
	Trauma (including renal biopsy)
	Tuberculosis
	Embolism
	Renal vein thrombosis
	Vascular malformation
Ureter	Stone
Ureter	Neoplasm
Bladder	Carcinoma
	Stone
	Trauma
	Inflammatory – cystitis, tuberculosis, bilharzia
Prostate	Benign prostatic hypertrophy
Prostate	Neoplasm
Urethra	Trauma
	Stone
	Urethritis
	Neoplasm
General	Anticoagulants
	Thrombocytopenia
	Haemophilia
	Sickle cell disease
	Malaria

Symptoms and signs

Family history, e.g. polycystic kidney. Painless haematuria is suggestive of neoplasia. Loin pain or ureteric colic suggests stone or clot colic associated with tumour. Suprapubic discomfort suggests bladder stone. Terminal bleeding with pain suggests bladder calculus. Urethral bleeding independent of micturition suggests a urethral lesion. Check the drug history. Spontaneous bruising. Palpable kidney. Palpable bladder. Enlarged prostate on examination PR.

Treatment

Appropriate to the underlying condition.

Obstructive uropathy

Symptoms and signs

Loin pain. Upper abdominal pain. Fever. Rigors – if infection. Ureteric colic. Hesitancy, poor stream, frequency, distended bladder with suprapubic discomfort. Uraemia may be presenting complaint. Palpable kidney. Palpable prostate.

Investigations

• KUB: enlarged renal outline, opaque calculi

• USS: confirms diagnosis and may demonstrate lesion

• IVU (→ Fig. 16.1): early stages show pelvic dilatation with clubbing of the calyces, site of obstruction, function of kidney, trabeculation of bladder, residual urine (if bilateral hydronephrosis and uraemia, no further information would be obtained from an IVU)

• CT scan

• Cystoscopy: cause of bladder outlet obstruction or bladder tumour

• Retrograde pyelogram defines exact site of obstruction.

Figure 16.1 Intravenous urogram. There is a right-sided hydronephrosis and hydroureter. Note the dilatation of the pelvis with clubbing of the calyces and also dilatation of the ureter down to its entry into the bladder.

Treatment

Directed at the underlying cause. With a small ureteric stone the obstruction may be relieved with the passage of the stone. The presence of acute infection or marked renal impairment requires urgent decompression of the urinary tract under antibiotic cover. This may be done by percutaneous nephrostomy, suprapubic cystostomy, ureteric catheter drainage or urethral catheter drainage. A non-functioning kidney, especially if infected, should be removed.

Complications

Infection: pyonephrosis. Stone formation in stagnant urine. Hypertension due to renal ischaemia. Traumatic rupture of a hydronephrotic kidney. Uraemia.

Calculous disease

Urinary calculi are often idiopathic. They also arise secondary to stasis and infection and also in association with metabolic disorders, e.g. cystinuria. Stones may form in the kidney or bladder. Ureteric calculi are in transit from the kidney to bladder. Stones occur in about 1% of the population. The majority is composed of calcium, magnesium ammonium phosphate, or urate.

Types of calculi

Calcium oxalate (75%)

‘Mulberry’ stones covered with sharp projections. They cause bleeding and are often black owing to altered blood on their surface. Because of their sharp surface they give symptoms when comparatively small. Occur in alkaline urine.

Phosphate (15%)

Usually compound of calcium, magnesium and ammonium phosphate. Smooth and dirty white. They may enlarge rapidly and fill the calyces taking on their shape, i.e. staghorn calculus. Occur in strongly alkaline urine.

Urate (5%)

Arise in acid urine. Hard, smooth, faceted and light brown in colour.

Cystine (2%)

Usually multiple. Arise in acid urine and are of metabolic origin owing to decreased reabsorption of cystine from the renal tubules. White and translucent.

Xanthine and pyruvate stones

Rare. Due to inborn error of metabolism.

About 90% of calculi are radio-opaque. Usually only urates are radiolucent, cystine stones being radio-opaque because of their sulphur content. Precipitating factors include: diet, dehydration, stasis, infection, hyperparathyroidism, idiopathic hypercalciuria, milk-alkali syndrome, hypervitaminosis D, cystinuria, inborn errors of purine metabolism, gout, and chemotherapy (excess uric acid following treatment of leukaemia or polycythaemia).

Treatment

Acute symptoms – ureteric colic:

• Relieve pain – diclofenac sodium i.m. or p.r.; or pethidine.

• Admit to hospital

• Bed rest

• Intravenous fluids or increased oral fluids

• Collect and sieve all urine to retrieve calculus for analysis

• Check radiographs to assess progress of stone

• Stones <4 mm will usually pass spontaneously; 50% of stones between 4 mm and 6 mm will pass spontaneously. Stones >6 mm usually require removal

• Obstruction and infection require removal of stone

• Stone removal may be carried out by: ureteroscopy and fragmentation of the stone; pushing the stone back into the renal pelvis followed by fragmentation with extracorporeal shock wave lithotriptor.

Routine treatment of established urinary calculus

Removal of renal or bladder calculus by open surgical technique is now rare. Minimal invasive surgery using endoscopic techniques or extracorporeal shockwave lithotripsy is now the treatment of choice.

Percutaneous nephrolithotomy

A nephroscope is inserted into the kidney under radiographic control via a previously dilated track. The stone is then removed by grasping forceps (if small), ultrasonically disintegrated and removed by suction or disrupted into small fragments by electrohydraulic or laser lithotriptors.

Extracorporeal shockwave lithotripsy

This consists of an external energy source focused to provide a high-pressure zone that is directed to fragment the calculus. The calculus is fragmented into small particles, which pass in the urine.

Open surgery

This is used less often. A stone may be removed through the kidney substance (nephrolithotomy), or through the renal pelvis (pyelolithotomy). Surgery may be needed to correct hydronephrosis associated with a stone. If the kidney is irreparably damaged, nephrectomy is required.

Bladder calculi

Small stones may be removed cystoscopically after crushing with a lithotrite or disintegration using an electrohydraulic lithotriptor. Large stones >5 cm are removed by suprapubic cystostomy.

The stone must be analysed. The underlying cause must be treated if possible, e.g. parathyroidectomy or correction of an obstructive lesion. Attempts should be made to prevent recurrence.

Prevention of recurrence

Up to 50% of patients may have recurrence within 5 years. Prevention involves: (1) high fluid intake, especially in hot weather; (2) reduce milk intake; (3) prompt treatment of urinary tract infections; (4) calcium stones: low-calcium diet, thiazide diuretics, acidify urine; (5) oxalate stones: reduce oxalate intake – exclude rhubarb, spinach, tomatoes, strawberries, tea and chocolate; (6) urate stones: allopurinol, urinary alkalinization.

Tumours of the renal tract

Kidney

Benign tumours are rare. Adenocarcinoma accounts for 80% of renal tumours. Transitional cell tumours occur in the renal pelvis. Squamous cell carcinomas may occur in the renal pelvis and are associated with squamous metaplasia due to chronic irritation caused by stone or infection.

Renal cell carcinoma

This arises from renal tubular epithelium. Males are affected twice as commonly as females. It usually occurs over the age of 40. There is increased incidence in smokers, coffee drinkers, industrial exposure to cadmium, lead, asbestos, aromatic hydrocarbons; renal cysts in dialysis patients; von Hippel–Lindau disease. Spread is by direct extension into perinephric tissues, by lymphatics to the para-aortic nodes, by the blood, along the renal vein (which may contain tumour), to bone, liver, brain and lung (cannon ball metastases).

Tags: Churchills Pocketbook of Surgery

Jun 14, 2017 | Posted by admin in GENERAL SURGERY | Comments Off

Unilateral	Pelviureteric junction obstruction • congenital pelviureteric junction obstruction • aberrant renal vessels • calculus • tumours of the renal pelvis Ureteric obstruction • calculus • ureteric invasion, e.g. cervical, rectal or colonic tumours • iatrogenic – damage at surgery
Bilateral	Urethral valves
	Urethral or meatal stenosis
	Prostatic enlargement
	Extensive bladder tumours
	Retroperitoneal fibrosis

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