Kidney and Ureteral Stones

Kidney and ureteral stones are very painful. Many pass through the ureter and into the bladder then through urethra without intervention but usually with great discomfort.

When a stone is present it is important to ensure that urine flow into the bladder is not interrupted otherwise irreversible kidney damage can be caused. For this reason a stent may be inserted through the urethra, and the bladder to pass through the ureter and into the kidney, One side of the stent is left in the kidney and the other in the bladder. This prevents the ureter from blocking. The stent is left in place before during and after an extracorporeal lithotripter is used to fragment the stone. After the lithotripsy, the stent assists the passage of the gravel into the bladder. When the gravel clears, the stent may be removed.

The ureter is often quite convoluted so without a stent in place, gravel can collect in a bend and cause a blockage so the straightening effect of the stent is useful.

Urine is normally passed through the ureter by a peristaltic action. It has been shown that when a stent is in place, the gravel and urine are driven by the peristaltic action around the outside of the stent rather than through the lumen of the stent. Therefore a thin stent is excellent fo rfacilitating clearace of gravel, as it straightens the urethra and causes much less obstruction than the more bulky hollow stent. However if a large ureteral stone is present, a hollow stent is best because it assures that there is a passage for urine to pass to the bladder even if the stone causes a total obstruction.

Genesis medical supplies a full range of ureteric stents including the unique "Nitenol" titanium-nickel alloy "Zebra" stent. This stent is thin and relatively soft - the small profile shortens gravel clearance time by about 40%.

The range of standard stents are comprised of a special compound which softens after positioning with body heat and this maximises comfort.

For details e-mail us.