Hydronephrosis, the swelling and stretching of the urine collecting structures within the kidney, occurs when structural or functional disorders of the urinary tract system interfere with the normal flow of urine. Although hydronephrosis can develop in adults due to conditions such as kidney stones, an enlarged prostate or pregnancy, it most commonly affects children. Hydronephrosis can affect one or both kidneys and can occur due to an obstruction or the backflow of urine from the bladder to the kidney. The treatment for hydronephrosis depends upon the severity of the condition and the underlying cause.
Lithotripsy
The formation of a kidney or bladder stone can result in hydronephrosis in adults. Urine contains waste products removed from the blood. When substances such as uric acid, ammonia, magnesium or calcium fall out of solution, they can harden into a small stone.
A stone formed in the kidneys can travel into the ureter and become lodged, resulting in a blockage. A stone formed in the bladder can block the flow of urine out of the bladder, resulting in a backflow to the kidneys. Lithotripsy uses high-energy sound waves to break up the stone and remove the blockage causing the hydronephrosis.
Pyeloplasty
Many children with hydronephrosis develop the disease in utero due to an abnormality formed in the urinary tract system during development. The Children's Hospital Boston reports that narrowing where the kidneys meet the ureters, called the ureteropelvic junction, is the most common type of obstruction. Although many cases resolve on their own as the child grows, if doctors classify the hydronephrosis as moderate or severe and suspect damage to the kidney may occur, they can perform a surgical procedure known as a pyeloplasty.
During a pyeloplasty the surgeon removes the obstructed portion of the ureter and reconnects the ureter to the kidney. Doctors can perform the procedure laproscopically in which the surgeon utilizes robotic surgical equipment, or open in which the surgeon enters through an incision on the side just under the ribs. The surgeon inserts a stent in the ureter to help the tube remain open during healing.
Nephrostomy Tube Placement
In cases when doctors cannot determine the cause of the hydronephrosis or the obstruction cannot be quickly corrected but the swelling in the kidney results in an infection, severe pain or kidney failure, inserting a nephrostomy tube can relieve the hydronephrosis. A nephrostomy tube is a long, thin plastic tube the doctor inserts through the skin and into the kidney, as described by the National Institutes of Health. The urine then drains directly from the kidney out of the body, bypassing the ureters, bladder and urethra.
