Introduction

Urinary tract disorders are common and comprise a significant part of the workload of GPs, general physicians, paediatricians and surgeons. Many general surgeons deal with urological problems, which make up about 25% of their workload. Prostate disorders account for at least half of the work in urological surgery. The main conditions are benign prostatic hyperplasia, affecting about 10% of ageing males in Western countries, and prostatic carcinoma, now the second most common cancer in men worldwide and the commonest cancer diagnosed in men in developed countries. The remaining surgical disorders of kidney and urinary tract can be divided into five broad groups: tumours, stone disease (urolithiasis), infections, congenital abnormalities and finally, local and systemic disorders secondarily involving the urinary tract.

This chapter deals with the symptoms, signs, approach to investigation and diagnosis of urinary tract disease. The various disease entities are then discussed in the following five chapters.

Symptoms caused by intrinsic disease of the urinary tract

Outflow of urine from the kidney may become impeded by urinary tract obstruction, which may secondarily interfere with renal function. Chronic obstruction to bladder outflow or bilateral upper tract obstruction may lead to renal failure, often without any localising symptoms.

Benign prostatic hyperplasia is the most common prostatic disorder, and usually presents with symptoms of bladder outflow obstruction (i.e. micturition disorders or urinary retention or both) and sometimes with haematuria. Prostatic obstruction predisposes to bladder infections or stones and the patient may present with the consequent symptoms.

Prostate cancer may present with bladder outflow obstruction similar to benign hyperplasia or it may be discovered at an asymptomatic stage at a medical check-up, by digital rectal examination (DRE) or by a blood test (prostate specific antigen, PSA). Some cases are first diagnosed because of symptoms of metastases, such as bone pain.

Chronic prostatitis may be bacterial or abacterial and usually presents with a chronic perineal ache. In the acute form, bacterial prostatitis can present as a systemic illness (or even Gram-negative sepsis) with urinary symptoms and an exquisitely tender prostate. Occasionally, a prostatic abscess develops.

The important urinary tract tumours, stone diseases and infections are outlined in Table 34.1. Any of these may present with haematuria. Disorders which cause urinary stasis also predispose to urinary tract infection.

Congenital abnormalities may involve the kidneys, ureters, bladder, urethra and genitalia, either alone or in combination. Most of the serious abnormalities are recognised antenatally by ultrasound, at birth or in early childhood. The exceptions are polycystic disease and medullary sponge kidney, which usually present in adulthood. Less serious congenital abnormalities such as duplex systems may predispose to urinary tract infections because of abnormal flow dynamics. These abnormalities may be discovered at any age during investigation of recurrent urinary infections. Congenital disorders which present mainly in adulthood are discussed in Chapter 39 and those presenting mainly in childhood in Chapter 51.

Urinary symptoms caused by non-urinary disease

The urinary tract sometimes becomes secondarily involved in local inflammatory conditions such as Crohn’s disease or diverticular disease. Fistulae may form, resulting in passage of flatus and/or faeces in the urine (pneumaturia and faecuria). Retroperitoneal fibrosis, diverticulitis, tumours of the prostate, cervix or colon, and sometimes aortic or iliac aneurysms may secondarily involve the ureters and cause upper urinary tract obstruction.

The common symptoms of urinary tract disease

These fall into eight categories:

Causes of haematuria (see Fig. 34.2 for renal causes)

Tumours are a common cause of frank or microscopic haematuria and must be suspected even if another possible cause is found. Haematuria from tumours is typically painless. However, carcinoma-in-situ of the bladder, a dysplastic condition with a high probability of progression to invasive carcinoma, usually presents with irritative voiding, dysuria and haematuria. Irritation from infection or stones may also cause bleeding, but is usually accompanied by pain or dysuria. If the urethra is obstructed by prostatic enlargement, straining at micturition may cause bleeding from dilated veins at the bladder neck.

Trauma to a normal kidney may cause frank haematuria if substantial force has been applied, but microscopic haematuria is common after minor trauma in contact sports and rarely indicates significant injury. Enlarged kidneys are more susceptible to trauma, whatever the primary pathology. In hydronephrosis or polycystic kidneys, minor blunt trauma may cause gross haematuria.

Sometimes urine becomes red with haemoglobin rather than blood. In young people this may be induced by vigorous exercise such as jogging (exercise haemoglobinuria and haematuria). These patients are believed to have defective red cell membranes which makes them more vulnerable to trauma. Exercise haemoglobinuria is self-limiting and requires no treatment.

Haematuria also occurs in renal parenchymal inflammation such as glomerulonephritis or arteritis. Haematuria may also be caused by microemboli impacting in the kidneys, as in atrial fibrillation or infective endocarditis. Any urinary tract disorder with a potential for haematuria is more likely to be revealed when a patient is on anticoagulant therapy or develops a bleeding diathesis.

Diagnostic features of haematuria

The stage of micturition at which blood appears is sometimes diagnostically useful. Blood from the kidneys, ureters or bladder wall will completely mix with the urine, and be present throughout the urinary stream. Urethral bleeding may leak out independently of micturition, or be seen only at the beginning or end of the urinary stream. Blood arising from the bladder neck or posterior urethra may sometimes present as terminal haematuria. Gross bleeding may result in the passage of clots.

Haematuria on dipstick testing should be confirmed by urine microscopy for red blood cells, and checked for infection by culture and sensitivity. Microscopic haematuria may represent a noteworthy lesion anywhere in the urinary tract and must be taken seriously; however, a significant cause is found in only 5–25% of patients.

• Urinary frequency

• Nocturia

• Urgency

• Hesitancy

• Poor urinary stream

• Post-micturition dribbling

Lower Urinary Tract Symptoms (LUTS)

This term encompasses the symptoms of hesitancy, poor stream, terminal dribbling and incomplete bladder emptying with frequency, nocturia, urgency and urge incontinence. Although these occur in prostatic obstruction, similar symptoms also occur in bladder neck obstruction, urethral stricture, bladder calculi and lower urinary tract infection. The severity of symptoms can be estimated using the International Prostate Symptom Score (see Box 35.1, p. 446).

Acute retention

Acute urinary retention is often very painful and occasionally occurs in normal individuals, usually males, particularly postoperatively, when fluid overload, drugs, pain, the supine posture, anxiety or embarrassment are responsible. Similar factors may precipitate an episode in men with asymptomatic prostatic enlargement. Occasionally acute retention is caused by an obstructing blood clot (clot retention) or stone.

In females, acute urinary retention may also occur in pregnancy if the enlarging uterus becomes wedged in the pelvis at about 14 weeks’ gestation. Large ovarian cysts or uterine fibroids may cause similar obstruction. Other possible causes include neurological disorders such as sacral nerve injury, herpes zoster and multiple sclerosis.

Chronic retention

Chronic retention is often painless and occurs with structural or functional abnormalities of bladder muscle or the sphincter mechanism. Less commonly, it is caused by persistent urethral obstruction. In chronic retention, voiding of urine is often incomplete. The problem progresses until the residual volume approaches maximum bladder capacity. Voiding then usually occurs by ‘overflow’ and the bladder usually becomes abnormally distended. When obstruction is prolonged and severe, the bladder muscle hypertrophies, bladder diverticula may develop, and back pressure on the kidneys can cause uraemia and renal failure. At any stage, complete cessation of flow, i.e. acute-on-chronic retention, may be precipitated by overfilling (often alcohol-induced), urinary tract infection or constipation. The most common cause of chronic retention is bladder outflow obstruction caused by a hypertrophied bladder neck or prostatic enlargement. It may also be caused by lower spinal neurological problems, e.g. central protrusion of lumbar intervertebral discs damaging the S2, 3, 4 detrusor muscle innervation.

Loss of cortical control

Loss of inhibitory control over reflex voiding may occur in disease of the cortex, such as the dementias, or in spinal cord disease above the sacral reflex level, such as multiple sclerosis. Traumatic paraplegia is a common cause of complete loss of cortical control. The resulting incontinence may be described as a suprasacral neurogenic bladder. The bladder fills to normal capacity and then empties spontaneously, more or less completely, leaving little residual urine.

Disorders of sacral reflex control of detrusor and sphincter function

If the sacral reflex arc is damaged on either afferent or efferent sides, reflex contraction of the detrusor and relaxation of the sphincter are lost. This may occur in low spinal trauma or systemic or local disease such as myelomeningocoele, diabetic neuropathy or invasive pelvic tumours. The bladder becomes grossly distended and urine passively overflows causing constant dribbling incontinence. This can be improved by regular manual emptying of the bladder by abdominal pressure, or more effectively by intermittent self-catheterisation (ISC). This form of incontinence is described as sacral neurogenic bladder. The large residual urine volume predisposes to infection and should be emptied regularly if possible.

In some patients, typically middle-aged women, reflex control of detrusor activity becomes hypersensitive so the voiding reflex is initiated when bladder filling is well below full capacity. This hypersensitivity results in small volumes of urine being passed frequently and precipitously to produce urge incontinence. The condition is known as overactive bladder or detrusor overactivity and can lead to a minor but upsetting form of incontinence.

Bladder infection produces excessive sensory irritation and activation of the voiding reflex. In young children and the elderly, this may be responsible for incontinence with none of the usual symptoms of infection.

Persistent bladder outflow obstruction due to prostatic enlargement causes progressive stretching of the bladder and damages the voiding reflex. The result can be a hugely distended, flaccid, hypotonic bladder. Dribbling overflow incontinence may persist even when the obstruction has been removed.

Structural abnormalities of the bladder or sphincter

The most common condition in this category is stress incontinence, in which the sphincter is weak. Any sudden increase in pressure on the bladder (such as coughing, sneezing or laughing) causes small quantities of urine to leak out. Stress incontinence is usually seen in parous women and results from pelvic floor damage during childbirth. There is often a degree of uterine prolapse and cystocoele. Various operations can alleviate this.

Prostatectomy (transurethral or open) may damage the sphincter, as may locally invasive tumours or pelvic fractures involving the proximal urethra. Tuberculosis, radiotherapy and interstitial cystitis in its severest form may cause severe bladder contraction and frequency to the point of incontinence.

Incontinence is a feature of several rare congenital abnormalities such as epispadias or an ectopic ureter opening below the sphincter mechanism. These should be excluded in a child who fails to develop continence.

General examination

A full general examination should pay special attention to a sallow complexion and signs of weight loss which could indicate uraemia, particularly if accompanied by a uriniferous smell and scratch marks indicating itching. Blood pressure must be measured in every case as hypertension may be a feature of pyelonephritis, renal artery stenosis, polycystic kidneys or glomerulonephritis.

Abdominal examination

Abdominal inspection may reveal asymmetry due to a large renal mass; this may be a nephroblastoma in a child or polycystic kidneys in an adult. In chronic retention, a large, sometimes asymmetrical bladder may be visible. The loins should be carefully inspected from the back; a subtle fullness may indicate a renal mass or a perinephric abscess.

A bimanual technique is used when examining the abdomen for kidney enlargement. One hand palpates the subcostal region anteriorly while the other hand is placed posteriorly in the renal angle to push the kidney forward on to the palpating hand. The kidneys are impalpable unless they are enlarged or displaced, except in a very thin patient. A renal mass may move with respiration and, because it is retroperitoneal with bowel anteriorly, should also have an area of resonance on percussion overlying it. The main causes of an enlarged kidney are hydronephrosis, polycystic disease, renal cell carcinoma and nephroblastoma (Wilms’ tumour) in children. Loin tenderness is uncommon in non-acute renal disorders except in chronic perinephric abscess. Tenderness is usually found in acute conditions, such as pyelonephritis or acute obstruction. Renal tenderness can be distinguished from vertebral tenderness by gently tapping the spinous processes. This will cause pain if the tenderness is vertebral.

The lower abdomen is palpated for an enlarged or distended bladder, which is felt as a soft mass arising from the pelvis, sometimes asymmetrically. It is dull to percussion and pressure on it may induce an urge to void; bladder distension is easily confirmed on ultrasound examination. A suprapubic mass in the male usually indicates urinary retention, but occasionally it is a colonic carcinoma or a large bladder tumour or stone (all firm to palpation). In the female, ovarian masses, pregnancy or uterine fibroids are more common causes of a suprapubic mass than urinary retention. Finally, auscultation along the 12th rib posteriorly may reveal the bruit of renal artery stenosis.

Rectal examination

Rectal examination should be performed in both sexes. In females, a vaginal examination may also be indicated. In the male, the prostate is palpated per rectum for size, shape and consistency (Fig. 34.3). The normal prostate is about 3 cm in diameter and weighs 10–15 g; it can be massively enlarged and weigh over several hundred grams, so that its upper edge may be out of reach of the examining finger. Most prostatectomy operations leave a capsular remnant so that the prostate appears palpable after prostatectomy and may be of a firmer consistency.

The severity of prostatic obstructive symptoms depends not on the prostatic diameter but on the extent of encroachment upon the urethra. In some cases, an enlarged median lobe lying posteriorly above the bladder outlet may act as a flap valve, intermittently obstructing urine outflow.

On palpation, the normal prostate has a smooth surface and a firm consistency and is divided into two lateral lobes by a midline groove. In prostatic hyperplasia, enlargement is usually symmetrical, and the midline groove is maintained. Consistency remains normal. In contrast, a prostate infiltrated with carcinoma is irregular and asymmetrical. There are often hard nodules, and the median groove may be lost. In advanced cases, the tumour may be felt invading laterally into the pelvis or posteriorly around the rectum (see Fig. 34.4). Digital examination can help distinguish benign from malignant prostatic enlargement in gross cases, but if carcinoma is suspected, transrectal ultrasound scanning (TRUS) using a rectal probe is performed, together with multiple needle biopsies under ultrasound guidance. Note, however, that there is a 2% risk of systemic sepsis and the procedure needs to be covered with a short course of antibiotics, e.g. ciprofloxacin. The symptom of prostatic tenderness is uncommon and may indicate prostatitis.

Are any blood tests likely to be helpful in diagnosis?

Blood tests that can be useful are summarised in Box 34.3.

When prostate cancer is suspected, prostate specific antigen (PSA) levels should be estimated and fractionated into free PSA, total PSA and their ratio. The free PSA is more likely to be raised in carcinoma and is a reliable indicator if the level is markedly elevated, although the higher the level, the greater the volume of cancer. In biopsy-proven prostatic cancer, persistently raised PSA levels above 20 are likely to indicate metastatic disease. However, the level may be normal in the presence of a small-volume cancer.

Total PSA rises with age and, in benign hyperplasia, tends to rise in proportion to prostate mass. Acute retention, urinary tract infection, any urethral instrumentation or biopsy of the prostate causes elevation of the PSA for up to 6 weeks; standard digital rectal examination does not affect PSA level.

What urine tests are indicated?

Any urinary symptoms should prompt collection of a clean midstream urine (MSU) specimen for microscopy and bacteriology. Microscopy will show the presence or absence of significant numbers of red blood cells (microscopic haematuria), white cells (pyuria) and bacteria (bacteriuria). However, the cells can lyse if the specimen is kept overnight at room temperature.

Bacteriuria of more than 5 × 10⁵ per cubic millimetre is considered to indicate significant infection. The urine is cultured to identify the organisms, and organisms are tested for antibiotic sensitivity. Culture-negative urine (sterile pyuria) is characteristic of urinary tract tuberculosis, urinary stone, bladder tumour, prostatitis or (most commonly) a partly treated urinary tract infection. In sterile pyuria, three early morning urine specimens should be examined for acid-fast bacilli and cultured. Bacteriuria without significant pyuria usually indicates contamination of the urine specimen. Casts found on microscopy suggest a nephritic (renal inflammatory) process. The presence of epithelial cells indicates perineal contamination of the specimen, a common problem in females and infants.

Urine cytology is a useful screening test for urothelial tumours in people at high risk, particularly those who have been exposed to industrial carcinogens. The test has a high positivity in carcinoma-in-situ and poorly differentiated tumours. Cytology needs to be performed on freshly voided urine. Some centres with an efficient local service use cytology for long-term follow-up of patients with treated bladder cancer.

Where is the lesion?

Investigations for localising urinary tract pathology are summarised in Table 34.3.