Most people with urinary tract calculi are asymptomatic. Pain is the commonest symptom and may be sharp or dull, constant, intermittent or colicky. When urinary tract obstruction is present, measures that increase urine volume, such as copious fluid intake or diuretics, including alcohol, make the pain worse.Physical exertion may cause mobile calculi to move, precipitating pain and, occasionally, haematuria. Calyceal colic, i.e. pain resulting from movement of stones within the calyces, is a real entity, but whether small calyceal calculi are the cause of backache or not is often difficult to decide.
Ureteric colic occurs when a stone enters the ureter and either obstructs it or causes spasm during its passage down the ureter (Fig. 9.23). This is one of the most severe pains known. Radiation from the flank to the iliac fossa and testis or labium in the distribution of the first lumbar nerve root is common. Pallor, sweating and vomiting often occur and the patient is restless, tending to assume a variety of positions in an unsuccessful attempt to obtain relief from the pain. Haematuria often occurs. Untreated, the pain of ureteric colic typically subsides after a few When urinary tract obstruction and infection are present, the features of acute pyelonephritis or of a Gramnegative septicaemia may dominate the clinical picture. Vesical calculi associated with bladder bacteriuria may present with frequency, dysuria and haematuria; severe introital or perineal pain may occur if trigonitis is present. A calculus at the bladder neck or an obstruction in the urethra may cause bladder outflow obstruction, resulting in anuria and painful bladder distension. Physical examination should include a search f’)r corneal or conjunctival calcification, gouty tophi and arthritis and features of sarcoidosis.
DIAGNOSIS AND INVESTIGATION
A history of possible aetiological factors should be obtained, including:
• Occupation and residence in hot countries likely to be associated with dehydration
• A history of vitamin D consumption
• Gouty arthritis
Calcified papillae may mimic ordinary calculi, so that causes of papillary necrosis such as analgesic abuse should be considered. Investigations should include a mid-stream specimen of urine for culture and measurement of the blood urea and electrolytes and serum creatinine and calcium levels. Plain abdominal X-ray, renal tomography and excretion urography are the mainstay of diagnosis. Pure uric acid stones are radiolucent. Mixed infective stones in which organic matrix predominates are barely radiopaque. Calcium-containing and cystine stones are radiopaque. Calculi overlying bone are easily missed. Staghorn calculi may be missed on excretion urography . Uric acid stones may present as a filling defect after injection of contrast medium.
Such stones are readily seen on CT scanning. Excretion urography is carried out during the episode of pain; a normal urogram excludes the diagnosis of pain due to calculous disease. The urographic appearances in a patient with acute left ureteric obstruction are shown. The urine of the patient should be passed through a sieve to trap any calculi passed for chemical analysis.
Adequate analgesia should be given, e.g. morphine 15- 30 mg i.m. repeated as necessary. Alternatively an NSAID can be tried. A high fluid intalce and, if feasible, increased physical activity are recommended but the efficacy of these measures is doubtful. Stones less than 0.5 ern in diameter usually pass spontaneously and can be left. Stones greater than 1 ern in diameter usually require intervention.
Persistent pain, frequent bouts of severe pain, or anuria, are indications for further therapy. Intervention is also required if a stone is not moving though causing only partial obstruction in the absence of infection. With the advent of ercutaneous surgery and extracorporeal shockwave lithotripsy (see below) there has developed a trend towards earlier intervention in such cases. Complete obstruction or the coexistence of UTI with partial obstruction should prompt even earlier intervention owing to the increased risk of permanent kidney damage in these circumstances. Stones may be removed by a cutting operation:
NEPHROLITHOTOMY for renal calculi PYELOLITHOTOMY for stones in the renal pelvis.
URETEROLITHOTOMY for ureteric stones Cutting operations can now be avoided by using either percutaneous nephrolithotomy or extracorporeal shockwave lithotripsy. In the former, stones in the calyces and renal pelvis are removed by creating a percutaneous track down to the collecting system followed by endoscopic removal along this track. In the latter, shock waves are focused upon the renal calculi, causing them to fragment. Most of the fragments then pass spontaneously via the urethra. Fragments that do not pass can be removed percutaneously Ureteric stones may be removed endoscopically or may be pushed up into the upper urinary tract, to allow percutaneous nephrolithotomy or extracorporeal shock-wave
lithotripsy. Large renal stones need to be reduced in bulk by percutaneous means before lithotripsy can be expected to be successful. Some staghorn calculi are best dealt with by open operation.
Bladder stones can be removed endoscopically. They May be dealt with by direct electrohydraulic disintegration at cystoscopy or may be gripped in a lithotrite and crushed, the stone fragments then being washed out. Open cystotomy is required for very large bladder stones.