Nephrostomy is an artificial connection between the kidney and the skin surface. It is an important intervention in acute disruption of urine outflow from the renal pelvis, which aims to prevent hydronephrosis and kidney damage.
Typical indications are urinary stones, kidney cancer or locally growing cancers of other nearby abdominal organs, such as the ovarian cancer. When any of these factors blocks the urinary tract and flow of urine, the urine accumulates above the obstruction. When untreated, it causes dilation of the renal pelvis, kidney overpressure and hydronephrosis. Long-lasting untreated hydronephrosis can damage the kidney and cause chronic renal failure. In addition, urine accumulation increases the risk of urinary tract infections including pyelonephritis.
The procedure is performed in local anesthesia. After that, the doctor uses an imaging method (usually ultrasound) to assess the location of the affected kidney and renal pelvis. When this is done, the renal pelvis is punctured with a special hollow needle, through which the doctor inserts a special guide wire into the pelvis. A hollow stent is inserted along the wire to take the urine away. The urine continuously flows and it must be collected in special nephrostomic bags. The nephrostomy may be either temporary, or permanent.
Schema - principle of nephrostomy
The procedure may be associated with bleeding. This is not surprising given how richly perfused the kidney tissue is.
The main advantage of the procedure is immediate outflow of urine, which prevents further damage of the kidneys and bacterial infection. In addition, the newly created access to the uppermost part of the urinary tract allows introducing other working tools and solving causative factors of urinary flow obstruction.