Stone Disease (Urolithiasis)
Stone disease is a typical prosperity disease as are diabetes mellitus and arteriosclerosis. Men are affected twice as often as women. The risk of acquiring stone disease in a life time is approximately 5-10%, the risk of recurrence is about 30%. A variety of factors such as hereditary constitution, diet and fluid intake, lack of physical activity, medications and racial differences are responsible for stone formation. The main factor is supersaturation of the urine with stone forming substances. There are different types of stones such as calcium oxalate stones (the most common form), infection associated stones, uric acid stones and cystine stones. Not all stones necessarily cause symptoms but they can lead to irreversible kidney damage . In case a stone enters the ureter and causes obstruction, it can lead to excruciating colicky pain often associated with hematuria. The diagnosis is confirmed by a KUB film and an intravenous urogram. Ultrasound and urinalysis can further support the diagnosis.
The emergency treatment is pain management and decreased fluid intake. Absolute indication for hospitalization are stone induced obstructed infected kidneys, acute renal failure with oliguria, patients with a solitary kidney or intolerable pain. The following therapeutic options are available to us:
About 80% of all ureteral calculi pass spontaneously and do not require intervention. This is an option if the stone is under 5mm and the patient is asymptomatic without signs of obstruction or infection. A regular follow-up is necessary to avoid non-recognition of stone growth or asymptomatic obstruction.
Medical stone dissolving
Treatment with oral medication (urinary alkalinization) is successful in about 70% of uric acid stones, but only when urine flows around the stone. In certain cases passage of urine must be forced by placement of a ureteral stent. This form of treatment has limited possibilities for cystin stones, a rare type of stone.
Extracorporeal Shock wave treatment (ESWL)
ESWL treatment has almost completely replaced open stone surgery. Approximately 90% of all patients with urinary stones are treated by this method. The shockwaves disintegrate the stone into particles under 2mm and as a rule the resulting gravel is naturally eliminated in the urine. 80% of patients are stone free within 3 months after ESWL therapy. Side reactions, such as colic, hematuria, renal hematoma and obstruction are relatively rare. Additional supportive measures (ureteral or renal stents) are necessary in 30% of cases. Grave complications are very rare. ESWL can be applied throughout the entire urinary tract. Depending on the type of stone, the machine used and patient sensitivity, it is applied with strong analgesics or a peridural anesthesia. ESWL treatment is not applicable in patients with purulent kidney infections, bleeding disorders or pregnant women.
Ureteroscopic stone extraction
Percutaneous nephrolithotomy or ureteroendoscopy are carried out in about 10% of urinary stone cases, usually for a large stone mass, a difficult localization for ESWL or insufficient fragmentation.
Open stone surgery
Open stone surgery is a rarity and is only performed in less than 1% of all patients, with a very extensive stone mass (staghorn calculi) or combined with other surgical procedures for concomitant diseases.
The most important preventive measure is an adequate fluid intake resulting in daily urine production of over 2 liters. The urine should be clear and colorless. A specialized clinic is available to all stone patients. Based on urine and stone analysis a diet combined with oral medication is recommended. Contrary to previous assumptions, a low calcium diet does not seem to be important for patients with calciumoxalate stones. Instead, products containing calcium (milk and cheese) should be consumed in normal amounts. However, foods with a high oxalate content such as asparagus, rhubarb, spinach, ice tea, black tea and chocolate should be avoided.