Global Health Asia-Pacific September 2020 September 2020 | Page 37

2. Extracorporeal Shockwave lithotripsy (ESWL) ESWL is a popular treatment for stones <2cm in size in the kidneys and upper ureter. It is performed as an outpatient procedure, and involves the patient lying on a specially constructed treatment platform. Shock waves of varying intensities are created outside the body and transmitted through the skin and body tissues to converge on these stones. The stones are then shattered into smaller particles that pass easily through the urinary tract in the urine (figure 2). �ecovery time is relatively short, and most people can resume normal activities in a few days. Side effects of �SW� treatment include bruising and pain around the treated kidney; downstream blockage of stone fragments in the lower ureter; and incomplete stone clearance requiring multiple treatment sessions. Figure 3. (a) A flexible ureterorenoscope is used to access stones in the urinary tract. (b) Holmium laser and basket used to eradicate stones. 4. Percutaneous Nephrolithotomy (PCNL) For kidney stones > 2cm in size or occupying a significant part of the kidney (known as staghorn stones), �C�� is the treatment of choice for definitive stone clearance. This procedure is performed under general anaesthesia, usually with the patient lying prone on the surgical table. Under X-ray or ultrasound guidance, the urologist makes a tiny incision in the back and creates a tunnel directly into the relevant chamber of the kidney. �igid and �exible nephroscopes are used to locate to the stones, which are then shattered and removed using various devices (figure 4). A small nephrostomy tube is left in the kidney for a few days till residual bleeding clears up. Figure 2. Extracorporeal shockwave lithotripter for kidney stones. 3. Ureterorenoscopy (URS) For stones in the lower ureter <2cm, specially constructed small-calibre endoscopes are passed up the ureter to the stone’s location with the aid of guidewires under X-ray guidance. The stones may then be shattered using a Holmium laser probe under direct vision, and the fragments retrieved out of the ureter using special stone baskets. If the ureter or kidney is swollen from stone obstruction, a temporary plastic stent is left in the ureter to facilitate healing, and is subsequently removed using a cystoscope 4-6 weeks after the initial procedure. U�S is usually performed as an outpatient procedure under general anaesthesia. �ain after U�S usually resolves after 2-3 days, although blood in the urine will take slightly longer to clear up. In recent years, advances in endoscope technology have enabled urologists to use small-calibre �exible ureterorenoscopes to steer all the way up the upper ureter into the kidney, and remove kidney stones using Holmium lasers and stone baskets (figure �). This has proved most successful for definitive clearance of stones located in the lower chambers of the kidney, for which ESWL has poor stone clearance rates. Figure 4. Use of rigid and flexible nephroscopes to access stones in the kidney through a small incision in the skin. Which treatment is best for me? Urinary stones are a common cause of visits to the emergency department. Patients are usually referred on to the urologist, who will then advise on the most appropriate treatment approach based on the stone’s size, characteristics of the urinary tract anatomy, and clinical condition. Advances in medical therapy and surgical technologies now allow stones to be eradicated successfully with minimal scars, less pain and swift recovery. Dr.Gerald Tan Yau Min is a consultant urologist at Advanced Urology with over 23 years of clinical experience with a record of 1,500 robotic radical prostatectomies performed. He is internationally renowned for his expertise in minimally invasive and robotic surgery for prostate, kidney and bladder diseases. He may be contacted via email at enquiry@urology. com.sg. GlobalHealthAsiaPacific.com SEPTEMBER-OCTOBER 2020 35