- What is PCNL?
PCNL is a well established procedure, by which stones in the kidney or upper ureter are removed by making a small incision in the flank.
- What exactly is done?
Generally a 1 cm or less incision is made in the flank. A thin needle is passed through this incision into the kidney. This is done under fluoroscopy or x-ray control. A guide wire is left in the kidney and passage is then created around this guide wire by using dilators. 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 tract as drainage for one or two days.
- What is the main advantage of this approach?
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.
- What are the pre-operative tests that are required?
Apart from the routine blood and urine investigations, you will also need an ultrasound scan of the abdomen. An Intravenous Urogram (special x-rays to image the urinary tract) or CT IVU (computed Tomogram) 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.
- When would your doctor recommend this procedure?
This surgery would be recommended as a treatment of choice, if you have multiple kidney stones, larger than 2 cm kidney stones, bigger than 1 cm upper ureteric stones, stones in a calyceal diverticulum, or at times the lower pole of the kidney which cannot be effectively treated with either ureteroscopy or ESWL (Extracorporeal Shock Wave Lithotripsy). Renal stones with high Hounsfield units (greater than 1000 HU) are also preferably treated by PCNL.
This procedure is also performed following failure of other modalities of treatment such as medical therapy, ESWL, etc., for renal and upper ureteric stones.
- Does this procedure need anaesthesia?
Yes, it is commonly performed under general anaesthesia, and also therefore involves admission in the hospital.
- What is the success rate of clearance of stones with this procedure?
It 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.
- What is the post operative course?
Generally you need to stay in the hospital for 2 to 3 days after the procedure. You will also undergo additional x-rays or ultrasound studies, to determine if there are any residual stone fragments present. Large amount of residue will require the urologist to look again with a nephroscope to remove them. The other alternative is to treat the remaining fragments with ESWL.
From the site of the puncture, you will have a drainage tube, which would be removed in a day or two. Following the removal of the flank drainage tube, urine may leak for a day. In some patients a ureteric stent may be left indwelling. This stent would be removed by a small endoscopic procedure couple of weeks later. Post-operatively your urologist will also encourage a high fluid intake; to keep the daily volume of urine produced to more than 2 litres a day. You will also be told to do deep breathing exercises.
- What are the complications associated with this procedure?
By and large this procedure is safe. Some risks that can be associated with all surgical procedures are the possibility of bleeding (1%) sometimes requiring blood transfusion and infection.
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%), who will need secondary procedures or even a nephrectomy to control the same. When a supracostal puncture (above 12th rib) is made, complications would then include pneumothorax (air) or fluid accumulation in the thorax. Again the incidence of these is only 0 – 4%. Rarely in lower calyceal puncture surrounding organs like colon or spleen may be injured requiring additional surgical procedures.
- When can I get back to work?
This 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.
- What are the contraindications to this procedure?
These are bleeding disorders and pregnancy (due to risk of radiation). The others are medical problems making the patient unsuitable for anesthesia.
- When should I come back after the procedure?
Your first review would be at two weeks. If you have a ureteric stent (tube in your ureter), it is usually removed then. You would also need a urine culture to check for any urinary tract infection. Further reviews will be advised by your doctor. You may be asked to get X-ray or Ultrasound studies to document clearance of stones.
- How do I prevent recurrence of these stones?
It is advisable to maintain a urine output of about 2 liters per day. Your doctor may also advise dietary changes and medications, which will be individualized. Generally a high fibre diet, with avoidance of high calorie foods is recommended.