Nephrostomy

A nephrostomy or percutaneous nephrostomy is an artificial opening created between the kidney and the skin which allows for the urinary diversion directly from the upper part of the urinary system (renal pelvis). It is an interventional radiology/surgical procedure in which the renal pelvis is punctured whilst using imaging as guidance. Images are obtained once an antegrade pyelogram (an injection of contrast), with a fine needle, has been performed. A nephrostomy tube may then be placed to allow drainage. An urostomy is a related procedure performed more distally along the urinary system to provide urinary diversion. A nephrostomy is performed whenever a blockage keeps urine from passing from the kidneys, through the ureter and into the urinary bladder. Without another way for urine to drain, pressure would rise within the urinary system and the kidneys would be damaged. The most common cause of blockage necessitating a nephrostomy is cancer, especially ovarian cancer and colon cancer. Nephrostomies may also be required to treat pyonephrosis, hydronephrosis and kidney stones. Percutaneous nephrostomy is used in Whitaker test to differentiate recurrent obstruction or permanent dilatation after an operative surgery that corrects the cause of obstruction. This procedure is also used for antegrade pyelography to visualize the upper urinary tract system. Percutaneous nephrostomy is also used to treat hydronephrosis caused by kidney stones, pregnancy, stricture of the urinary tract, urinary tract/cervical/prostate tumours. Besides, infections such as urosepsis and pyonephrosis can also be drained by nephrostomy tube insertion. Percutaneous nephrostomy is also useful in divert urine away from diseased site to enhance healing. Examples of conditions that can be treated with such method are malignant/traumatic/inflammatory fistula, and haemorrhagic cystitis. Percutaneous nephrostomy is also used to provide access for chemotherapy/antibiotic/antifungal therapy, antegrade urethral stent placement, stone retrieval, and endopyelotomy (endoscopic surgery for the enlargement of the junction of renal pelvis and ureter).