Nephrostomy (also known as percutaneous nephrostomy, abbreviated to PCN) is an operation in which an artificial outlet is created through the skin (percutaneous) to drain urine from the kidney (a so-called renal fistula). A silicone tube (catheter) is inserted into the renal pelvis, through which urine can drain into a urine bag worn on the body.
A nephrostomy is usually a temporary solution to protect the kidney or to protect the urinary tract. In the longer term, it is mainly only used in palliative medicine, i.e. when a generally poor state of health does not permit therapeutic surgical interventions on the kidney, ureter or urinary bladder.
Nephrostomy is often an emergency measure when the urinary tract is blocked. It prevents urine from backing up, which leads to increased fluid pressure in the renal pelvis and can irreversibly damage the kidney tissue.
Possible causes of such a blockage of the urinary tract are
A nephrostomy may also be indicated to temporarily relieve the urinary tract after surgery. Another reason for a planned nephrostomy is the imminent or incipient loss of bladder function due to bladder cancer or other serious illnesses.
Schematic representation of kidney stones
A nephrostomy is performed in the radiology or urology department of a hospital or as an outpatient procedure in a urology practice. The surgical procedure is performed under local anesthesia and a sedative is administered to calm and relax the patient.
During the operation, the patient lies flat on their stomach or on their side. A puncture cannula with a connected plastic tube is first inserted into the renal pelvis from the back through a small incision.
The urinary tract. 1: Kidney. 2: Renal pelvis. 3: Ureter. 4: Bladder. 5: Urethra
The progress of the operation is monitored in real time using a dynamic imaging procedure - usually ultrasound, possibly X-ray computed tomography or 3D fluoroscopy. If one of the latter two methods is used, a contrast or fluorescent agent is first introduced into the urinary tract through the tube.
A so-called guide wire is then inserted. The tube and puncture cannula are removed and the catheter is advanced into the kidney via the guide wire. On the surface of the body, the catheter is fixed to the skin with a small surgical suture. A urine bag can be connected to the end of the catheter.
The entire procedure takes about an hour. Immediately after the nephrostomy or even later, further surgical procedures are usually performed, for example to remove the ureteral blockage.
If the renal catheter is intended as a longer-term solution, the silicone tube must be changed regularly to minimize the risk of infection and prevent the catheter from becoming blocked. This can be done on an outpatient basis and is necessary every four weeks to three months at the latest.
The exit point of the catheter is at the level of the affected kidney on the side of the back. Even if it has already healed, the patient must keep it clean, disinfect it regularly and cover it with sterile compresses and a special plaster, which also holds the catheter tube in place. The required urine bag is worn on the upper or lower leg with Velcro straps or in a pocket that can be fastened with Velcro fasteners. The bag can be emptied via a valve.
Modern urine bags are relatively flat and therefore inconspicuous, even when filled, thanks to a multi-chamber system. This means that the ability to participate in normal everyday life as well as mobility and the ability to work remain almost unrestricted. However, patients should not do any sport while wearing the nephrostomy catheter.
Illustration of the renal catheter and the correct way to wear the urine bag
Blockages in the urinary tract caused by kidney stones can usually be removed in the relatively short term. In this case, a temporary nephrostomy is the perfect solution. However, if there is a longer-term problem with the kidney, ureter or urinary bladder, a permanent solution is recommended once the situation has stabilized. The nephrostomy catheter is not strong enough as a permanent replacement for the bladder.
Problematic narrowing of the ureter is kept open by internal support of the ureter cross-section with a plastic scaffold, a so-called stent. If parts of the ureter had to be removed, ureter reconstructions are now possible using small strips of the bladder wall.
In cases of loss of function and removal of the bladder, the creation of an artificial urinary opening (urostomy) is an alternative to a permanent nephrostomy. The ends of one or both ureters can be sutured to the abdominal wall directly (ureteral skin drainage) or via a disused section of bowel (conduit). In these cases, a urine bag is still necessary, but the urostomy is mechanically more resilient than the nephrostomy catheter. Alternatively, certain amounts of urine can be stored in a so-called neobladder constructed from a piece of bowel.
If the kidney is already severely damaged due to back pressure or disease, removal of the organ including the ureter is also an option, provided the second kidney is still intact.
The Leading Medicine Guide's quality assurance is ensured by the following acceptance prerequisites.
