Diagnosis & Tests
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
- Urinary block
- No symptoms at all
For Urinary Stones
- To Evaluate the Presence of Stones: Preliminary urine analysis followed by an ultrasonography will provide most of the information required.
- To Study the Actual Kidney Function: An IVU series (special x-rays to image the urinary tract) needs to be performed.
- Additional Tests: In case of further doubts, additional tests such as isotope renogram, cystoscopy and retrograde studies of the urinary tract, and spiral CT may also be performed.
- MCU & RGU
- For PCNL: Apart from the routine blood and urine investigations, you will also need an ultrasound scan of the abdomen. An intravenous urogram (IVU – special x-rays to image the urinary tract) will delineate the anatomy and function of the kidneys, helping to plan the appropriate treatment. Urine cultures are mandatory to detect and treat urinary infection, prior to the procedure.
- For Patients Suspected to Have Other Metabolic or Endocrine Problems: Detailed testing will have to be conducted. These are generally reserved for those patients who have a recurrent stone formation.
Initial treatment will focus upon the relief of pain. After this, the next step will be to facilitate the passage of the stone or the removal of the stone itself.
80-90% of all stones smaller than 5 mm will pass out on their own. If the stone is smooth, even stones of 7-8 mm may pass out on their own.
Stones larger than this will invariably need to be removed by one of the many methods available. If there is an anatomical abnormality, the priority will be to correct that abnormality while removing the stone.
1-2 cm solitary stones in the kidney is preferably treated by ESWL. This is a method by which the stone is powdered when pressure waves from a machine are focused on the stone. The stone fragments will then pass out in the urine stream over a period of 1 to 12 weeks.
Larger stones in the kidney are preferably removed by PCNL. In this method, the patient needs to be admitted to the hospital. A small puncture is made from the back directly into the kidney, the stone is identified, fragmented and completely removed.
Stones lower down in the urinary tract may be treated either by ESWL or again, by endoscopic methods. In this, the stone is visualized and fragmented by passing a small endoscope into the urinary tract from outside.
Open surgery for stones in the ureter is used only in complicated cases.
Uric acid stones, which are generally seen only on the ultrasound, and not on the x-rays, if less than 1 cm, can easily be dissolved by simple alkalinization of the urine.
Most patients with urinary stones need to make certain minimal changes in their diet that may help in the prevention of a recurrence. These include:
- High intake of neutral fluids such as water, tender coconut water, diluted buttermilk, citrus juices, etc., is required unless contraindicated for some other reason. Patients should limit the amount of coffee, tea or milk taken to 1-2 cups a day.
- Food must preferably be vegetarian, and high in fiber.
- Meat eaters should restrict the amount of meat they eat so that their total protein intake is limited to 1 gram per kilogram per day.
- Cool drinks and soft drinks that contain a high amount of sugar, and calcium-rich foods such as sweets, sweets made using milk as an ingredient, etc., should be avoided, especially on an empty stomach.
Separate and specific changes in the diet may be suggested in the case of other conditions associated with urinary stones.
Patients who are suspected to have other metabolic or endocrine problems will need to undergo detailed testing. These are generally reserved for those patients who have the recurrent stone formation.
Percutaneous Nephrolithotomy (PCNL)
PCNL is a procedure for removing stones in the kidney or the upper ureter.
Illustration Showing How PCNL is Performed
PCNL is a well-established procedure by which stones in the kidney or the upper ureter are removed by making a small incision in the flank. Generally, an incision, that is 1 cm or less than 1 cm, is made in the flank. A guide wire is passed through this incision into the kidney. This is performed under fluoroscopy or x-ray control.
A passage is then created around this guide wire by dilatation. Through this passage, a nephroscope is passed into the kidney to visualize the stone and remove it. Larger stones can be fragmented by different methods and removed. Stones are therefore cleared easily. Once the procedure is complete, a tube is left through this track as drainage for one or two days.
The main advantage of this approach is that, unlike traditional open surgery, only a 1 cm incision is made in the flank. The stones can be visualized directly and removed. Unlike ESWL or ureteroscopy, the stones are removed in the same sitting and the kidney is cleared of calculi. The stay in the hospital is only for 3-4 days.
This surgery would be recommended as a treatment of choice if the patient has kidney stones larger than 2 cm, upper ureteric stones bigger than 1 cm, or at times for stones found in the lower pole of the kidney that cannot be effectively treated with either ureteroscopy or ESWL. This procedure is also performed following the failure of other modalities of treatment such as medical therapy, ESWL, etc., for renal and upper ureteric stones.
This procedure is commonly performed under general anesthesia, and therefore you also need to be admitted to the hospital for this procedure. In special circumstances, it can be performed under intravenous sedation, regional anaesthesia or local anaesthesia.
The success rate of clearance of stones with this procedure ranges between 90 to 95%. This actually depends upon the size, number, and location of these stones. Sometimes, complete clearance may require a second procedure after a few days.
For the post-operative course, the patient will generally need to stay in the hospital for 2 to 3 days after the procedure. He or she will also undergo additional x-rays or ultrasound studies, to determine if there are any residual stone fragments present. A large amount of residue will require the urologist to look again with a nephroscope to remove it. The other alternative is to treat the remaining fragments with ESWL.
From the site of the puncture, the patient will have a drainage tube and a urethral catheter, for a day or two. Following the removal of the flank drainage tube, urine may leak for a day. Post-operatively, the urologist will also encourage a high fluid intake to keep the daily volume of urine produced to more than 2 liters a day. By and large, this procedure is safe. Some risks that can be associated with all surgical procedures are the possibilities of bleeding (1%) and infection, sometimes requiring a blood transfusion.
Some patients have prolonged leakage of urine from the flank site, requiring ureteric stenting. Fever, if present, will require a change in antibiotic.
Rare complications include persistent uncontrolled bleeding due to arteriovenous malformations or pseudo-aneurysms (0.4%), which would need secondary procedures or even a nephrectomy to control the same. When a supracostal puncture (above the 12th rib) is made, complications would then include pneumothorax (commonly called collapsed lung caused due to the accumulation of air or gas in the space surrounding the lungs) or fluid accumulation in the thorax. Again, the incidence of these is only 0-4%.
The time by which a patient can get back to work would depend upon the magnitude of the stone burden and the number of tracts made. Most patients return to average activity levels within a week or so. A return to vigorous activity should probably take place after two weeks.
The contraindications to this procedure are bleeding disorders and pregnancy (due to the risk of radiation). The others are medical problems making the patient unsuitable for anaesthesia. It is advisable to maintain a urine output of 2 to 2.5 liters per day. Your doctor may also advise dietary changes and medications, which will be individualized. Generally, a high-fiber diet, with avoidance of high-calorie foods, is recommended.
Separate and specific changes in the diet may be suggested in case of other conditions associated with urinary stones.