Division of stone diseases
The Division of Stone Disease of the Jackson Heart Institute deals with the treatment of stones in the kidney, ureter, urinary bladder and urethral tube. Each part of the urinary system has its share of urinary stones. Ninety-seven percent of all urinary stones are located in the kidney and ureter. Only three are in the bladder and urethra.
Urinary stones are bio-minerals composed of both organic and inorganic substances, with calcium oxalate being the most prevalent type, accounting for at least 80% of all stones.
Renal stone disease has been a common affliction throughout human history, affecting approximately 15% of individuals over a 70-year lifespan. While rarely fatal, it can cause significant discomfort, including pain, urinary infections, and obstructive damage to the kidneys. Despite the availability of newer and more effective treatment methods, the underlying cause of stone formation often remains unknown, leading to a high risk of recurrence.
Urinary stone formation is a complex process that involves various factors. These factors include socioeconomic, genetic, dietary, anatomical, functional, and metabolic abnormalities, as well as medication use. It is important to note that when the concentration of a substance in urine exceeds its saturation point, it may crystallize and grow, ultimately leading to the formation of stones. Moreover, a lack of substances that inhibit crystal growth and aggregation in urine may also contribute to the formation of stones.
The common symptoms of urinary stone formation are:
Mild/moderate or severe pain
Passage of blood in the urine
Passage of tissue in the urine
Urinary tract infection
Burning sensation when urinating
No symptoms at all
To manage urinary stones, initial treatment aims to alleviate pain and subsequently facilitate the passage or removal of the stone. In most cases, stones smaller than 5 mm, and even smooth stones of up to 7-8 mm, will pass out on their own. However, larger stones require removal through various available methods, with priority given to correcting any anatomical abnormalities present.
For solitary kidney stones measuring 1-2 cm, Extracorporeal Shockwave Lithotripsy (ESWL) is preferred. ESWL involves applying pressure waves to the stone, which powder it. The fragments then pass out naturally in the urine stream over 1 to 12 weeks. For larger kidney stones, Percutaneous Nephrolithotomy (PCNL) is preferable. In PCNL, the stone is identified, fragmented, and completely removed through a small puncture in the back directly into the kidney.
For larger lower ureter stones or those that fail to pass out after a month, Laser Lithotripsy is used. This procedure involves visualizing and fragmenting the stone by inserting a small endoscope into the urinary tract through the urine passage. Open surgery is only used in complicated cases.
Uric acid stones, typically only seen on ultrasound and not x-rays, can be dissolved with simple alkalinization of the urine if they measure less than 1 cm.
Patients with urinary stones should make dietary changes to prevent a recurrence. These changes include consuming neutral fluids like water, tender coconut water, diluted buttermilk, and citrus juices unless otherwise contraindicated. Patients should limit their intake of coffee, tea, or milk to 1-2 cups a day, and their diet should be high in fiber and preferably vegetarian. Meat eaters should limit their protein intake to 1 gram per kilogram per day. Avoiding calcium-rich foods such as sweets made with milk, cool drinks, and soft drinks that contain high amounts of sugar, especially on an empty stomach, is also advisable.
Stone Pack (SP) tests are performed in our hospital to assess the risk of stone formation. These tests include blood and urine tests that check for factors such as blood sugar, renal function, and haematology. We also use ultrasound abdomen and X-ray KUB to determine the presence of stones. A plain CT scan of KUB provides more detailed information about the stone, and is considered the most sensitive test for detecting stones. Depending on various parameters, additional functional tests such as Intravenous Urography, Contrast CT KUB, or isotope renogram may be recommended by our urologists.
For patients who have recurrent stones, a family history of stone disease, stones in childhood, bilateral stones, or a solitary kidney, specialized tests are necessary. At our hospital, we perform customized blood tests called SP3 (which includes fasting and random blood tests) and 24-hour urine tests called SP4 (done on three consecutive days) to detect the cause of stone formation. In addition, we analyze any retrieved or spontaneously passed out stones using the FTIR (Fourier-transform infrared spectroscopy) method, which is considered highly accurate. Based on the results of these tests, appropriate dietary modifications and medications may be suggested by your doctor.
Percutaneous Nephrolithotomy (PCNL)
PCNL is a well-established procedure for removing kidney or upper ureter stones by making a small incision in the flank. During the procedure, a guide wire is passed through the incision into the kidney and a passage is created around it by dilatation. A nephroscope is then passed through the passage to visualize and remove the stones. The main advantage of this approach is that only a small incision is made, and the stones can be removed in the same sitting. The success rate of clearance of stones with this procedure ranges from 90 to 95%.
This surgery is recommended for patients with kidney stones larger than 2 cm, upper ureteric stones bigger than 1 cm, or stones found in the lower pole of the kidney that cannot be effectively treated with other modalities. The procedure is commonly performed under general anesthesia, and the patient usually stays in the hospital for 2 to 3 days post-surgery. The patient may have a drainage tube and a urethral catheter for a day or two and may experience urine leakage from the flank site for a day following the removal of the flank drainage tube.
Complications associated with this procedure include bleeding and infection, sometimes requiring a blood transfusion. Rare complications include persistent uncontrolled bleeding, which may require secondary procedures or even a nephrectomy, and pneumothorax or fluid accumulation in the thorax. The time for a patient to return to work would depend on the magnitude of the stone burden and the number of tracts made. The contraindications for this procedure are bleeding disorders and pregnancy. Dietary changes and medications may be recommended by the doctor, and a high-fiber diet with avoidance of high-calorie foods is generally recommended.