Urinary Stones “calculi” are firm masses that form in the urinary tract and may cause pain, bleeding, or an infection or even block of urine flow.
Anatomy of the Urinary Tract?
The Urinary Tract comprises the kidneys, ureters, urinary bladder, and urethra.
The kidneys are two bean-shaped organs located below the ribs toward the middle of the back, one on each side of the spine. The kidneys remove extra water and wastes from the blood, making urine. Moreover, body minerals are kept in a state of balance by the kidneys.
Two tubes “the ureters” carry urine from the kidneys to the urinary bladder; it’s an oval-shaped chamber in the center of the lower abdomen.
The bladder’s function is to act as a reservoir for urine; its elastic walls stretch and enlarge to store urine. Upon urinating, these walls flatten together when urine is emptied through the urethra out.
What are Stones?
Urinary Stones “calculi” are firm masses that form in the urinary tract and may cause pain, bleeding, or an infection or even a block of urine flow. Usually, they begin to develop in the kidneys and may enlarge in a ureter or the bladder. Depending on where a stone is located, it may be called a kidney stone, ureteric stone, or bladder stone. The process of stone development is called Urolithiasis.
It is formed when the urine is supersaturated with salt and minerals such as calcium oxalate, uric acid, and cystine.
Calcium represents the main constituent in 60-80% of stones, usually in combination with either oxalate or phosphate. They vary significantly in size from small ‘gravel-like’ stones to large stag-horn (because of its many projections that resemble a deer’s antlers) stones.
The stones may stay in the position in which they are formed, or move down the urinary tract, inducing symptoms (e.g. colic) along the way.
Studies have shown that men are more commonly affected than women, with a male: female ratio of 3:1, the peak age for developing stones is between 30 and 50 and recurrence is common.
Are there any risk factors for developing such Urinary Stones?
There are several recognizable risk factors that can increase the potential of a prone person to form stones, the most notable of which are:
Family history of renal stones.
Anatomical abnormalities in the urinary tract (e.g. horseshoe kidney, urethral stricture).
Certain metabolic ailments which increase excretion of solutes (e.g., chronic metabolic acidosis, cystinuria, hyperuricosuria).
Certain medications (e.g., diuretics such as triamterene, calcium/vitamin D supplements, calcium-based antacids).
Societies whose diet is very high in animal-source protein.
Urinary Tract Infections.
What are the Symptoms of such Stones?
Stones, especially tiny ones, may not cause any symptoms. Nevertheless, if its size is big enough to cause symptoms, usually the first symptom is extreme pain (renal colic), which begins suddenly when a stone moves in the urinary tract and gets lodged on its way down, blocking the flow of urine.
Typically, the person suffers a sharp, cramping pain in the back and side in the area of the kidney, flank, or in the lower abdomen. The pain tends to come in waves, gradually increasing to peak intensity, then fading, over about 20 to 60 minutes. Associating nausea and vomiting may occur. Pain may radiate to the groin, testicles or vulva.
If the stone is too large to pass straightforwardly, pain escalates as the muscles in the wall of the narrow ureter try to squeeze the stone down and into the bladder. As the stone moves down, it causes friction with the internal wall of the involved ureter and blood may appear in the urine. Burning sensation with urination might be another associating symptom.
If these symptoms are associated with fiver and body chills, this could mean an infection that needs immediate medical attention.
How can it be diagnosed?
Clinically, stones are suspected when someone presents with a picture suggestive of renal colic.
People presenting with tenderness over the back and groin or pain in the genital area without an obvious cause with an acute onset could also be suspected for urinary stones. Detecting blood in urine supports the diagnosis, but not all stones cause blood in the urine.
Urinary Stones can be found on x-ray (this diagnostic tool can only show calcium-containing stones) or ultrasound. These diagnostic images give the doctor valuable information about the stone’s size and location. Laboratory Blood and urine tests help detect any abnormal substance that might promote stone formation (e.g. abnormally high uric acid).
Non-enhanced Computed tomography (CT) spiral scan is now the imaging modality of choice. CT can locate a stone and also indicate the degree to which the stone is blocking the urinary tract.
Sometimes “silent” stones (those that do not cause symptoms) are found accidentally on a plain x-ray taken during a general health checkup, or assessment for another medical necessity.
How Kidney Stones are treated?
Fortunately, most urinary stones can pass through the urinary system with plenty of water to help move the stone along. Often, the patient stays home during this process, drinking fluids and taking pain medication as needed.
The doctor usually asks the patient to retrieve the passed stone for analysis. It can be caught in a cup designed only for this purpose.
What are the Symptoms of Such Stones?
For people with a history of stone formation and passing, a simple yet the rule of thumb lifestyle change is to drink more liquids as frequent as possible, water is best.
Someone who tends to form stones should drink enough liquids throughout the day to maintain urine output at 2-3 liters per day. Salt intake should be restricted.
According to medical assessment and advice, some patients may be told to avoid food with added vitamin D and antacids that have a calcium base. A person with highly acidic urine may need to eat less meat and poultry.
These foods increase the amount of acid in the urine. Also, foods rich in oxalate (e.g. chocolate and nuts) and urate-rich foods should be restricted to reduce oxalate intake.
Your treating Urologist may prescribe certain medications to help prevent calcium and uric acid stones. These medications control the amount of acid or alkali in the urine, key factors in crystal formation. The medication allopurinol can be useful in cases of Hyperuricosuria.
If Hypercalciuria is diagnosed, the Urologist will need to control it through prescribing certain diuretics, such as Hydrochlorothiazide. These medicines tend to decrease the amount of calcium released by the kidneys into the urine. They work best when sodium intake is low.
The pain of renal colic may be relieved with non-steroidal anti-inflammatory drugs (NSAIDs). If the pain is severe and the patient is hospitalized, centrally-acting medications (e.g. Tramadol) are sometimes needed.
Approximately 1 in 5 stones will not pass spontaneously and will require some form of urological intervention.
If the ureter is blocked or could potentially become blocked, a double J stent is usually inserted using a cystoscopy procedure. It is a thin hollow tube with both ends coiled (pigtail). It is also used as a temporary holding measure, as it prevents the ureter from contracting and thus reduces pain, buying time until a more definitive measure can be undertaken.
Procedures to remove stones include:
Extracorporeal Shock Wave Lithotripsy (ESWL) – can be used to break up a stone in the renal pelvis or uppermost part of the ureter. In this procedure, shock waves directed at the body by a sound wave generator break up the stone. The pieces of stone are then passed in the urine.
Percutaneous Nephrolithotomy (PCNL) – used for large stones (>2 cm), stag-horn stones and also cystine stones.
Ureteroscope – can be inserted into the urethra and through the bladder to remove small stones in the lower part of the ureter that requires removal. In some instances, the Ureteroscope can also be used with a device to break up stones into smaller pieces that can be removed with the Ureteroscope or passed in the urine (a procedure called intracorporeal lithotripsy). Most commonly, laser lithotripsy is used. In this procedure, a laser is used to break up the stone. It has an excellent success rate in experienced hands.
Open surgery – rarely done and usually reserved for complicated cases or for those in whom all the above have failed.
Recurrence of Urinary Stones is common and therefore patients who have had a urinary stone should be advised to adopt certain lifestyle measures which will help to prevent or delay recurrence, the most important of which is DRINKING PLENTY OF WATER.