A nephrostomy tube is a small, flexible catheter inserted through the skin and directly into the renal pelvis, the part of the kidney that collects urine. Its primary function is to create an alternate pathway for urine drainage when the normal route is blocked or impaired. This tube channels urine directly from the kidney into an external collection bag, bypassing the ureter and bladder. The procedure is a way to protect the kidney from damage or infection that occurs when urine backs up.
Clinical Indications and Necessity
The need for a nephrostomy tube most frequently arises from a blockage within the urinary system. When urine cannot flow from the kidney down to the bladder, pressure builds up, causing swelling called hydronephrosis. Common causes of this obstruction include kidney stones, malignant tumors (such as from cervical or colorectal cancer), and scarring or strictures within the ureter.
A time-sensitive indication for tube placement is the drainage of an infected and obstructed kidney, known as pyonephrosis or urosepsis. Trapped, infected urine can quickly lead to widespread infection and septic shock. Immediate drainage via a nephrostomy tube is often a life-saving intervention in these urgent cases.
Nephrostomy tubes also provide access for certain treatments or temporarily divert urine to allow injuries to heal. For instance, the tube creates a path into the kidney for procedures like percutaneous nephrolithotomy, a technique used to remove large kidney stones. It can also be used to divert urine away from a urinary fistula, which is an abnormal connection or leak in the urinary tract.
The tube may also be placed for diagnostic purposes, such as an antegrade pyelogram or a Whitaker test, to visualize the upper urinary tract and assess the extent of an obstruction. In cases of chronic, untreatable blockages, the tube may be needed for months or even years.
The Nephrostomy Tube Placement Procedure
The placement of a nephrostomy tube is a minimally invasive procedure typically performed by an interventional radiologist or a urologist. The patient is positioned, usually lying on their stomach or side, and receives a local anesthetic to numb the skin and deeper tissues. Sedation is often administered intravenously to help the patient relax.
The physician uses real-time imaging guidance, such as ultrasound or fluoroscopy (a type of X-ray), to precisely locate the kidney and the internal urine-collecting system. A fine needle is then carefully inserted through the skin and into the targeted collecting system.
Once the needle is correctly positioned, a flexible guidewire is threaded through the needle and into the kidney’s collecting system or down the ureter. The needle is removed, leaving the guidewire in place. A series of small tubes, called dilators, are passed over the guidewire to gently widen the tract through the tissue and muscle.
Finally, the nephrostomy tube itself, a catheter with a curled tip or locking mechanism, is advanced over the guidewire into the kidney and secured. The curled tip, often called a pigtail, helps prevent the tube from slipping out. The external end of the tube is connected to a drainage bag, and a dressing is applied to the insertion site to keep it clean and protected.
Essential Daily Management and Care
Daily care focuses on maintaining a clean insertion site, ensuring the tube remains open, and properly managing the collection system. Hand hygiene is required before and after handling the tube, dressing, or drainage bag to prevent bacteria from entering the urinary tract. The dressing must be kept clean, dry, and secure, and it is typically changed every two to three days, or immediately if it becomes soiled or wet.
When changing the dressing, the skin around the tube should be gently cleaned with soap and water or sterile saline to remove any dried drainage or crusting. The tube must be secured firmly to the skin with tape or a specialized fixation device to prevent pulling or dislodgement.
The drainage bag must always be kept below the level of the kidney to allow gravity to facilitate urine flow and prevent backflow. The bag should be emptied when it is about half to two-thirds full, which may be every few hours depending on fluid intake. For long-term tubes, the catheter requires routine replacement, often every two to three months, to prevent the buildup of mineral deposits and bacteria that can cause blockages or infection.
Fluid intake is an important part of tube management; patients are generally encouraged to drink between 1.5 to 2.5 liters of fluid daily unless advised otherwise. This increased fluid helps flush the system, maintain tube patency, and reduce infection risk. While showering is usually permitted after the initial healing period, the insertion site must be covered or the dressing changed immediately afterward to prevent moisture from causing skin irritation or harboring bacteria.
Potential Complications and When to Seek Help
While nephrostomy tube placement is generally safe, patients must monitor for signs of potential complications that require immediate medical attention. Infection is a common risk because the tube provides a direct path from the skin to the kidney. Symptoms of infection include a fever exceeding 101°F, chills, increased pain in the back or side, or the presence of pus-like or foul-smelling drainage from the tube site.
A blockage or dislodgement of the tube is another concern. A blockage is suspected if there is little to no urine draining into the bag for several hours, or if the patient experiences severe pain in the kidney area. Leakage of urine around the tube site can also indicate a partial blockage or poor tube position.
Bleeding is a complication to watch for, although mild pink- or grapefruit-colored urine is common for a few days after the procedure. However, the presence of bright red urine or large blood clots in the drainage bag warrants immediate medical evaluation. If the nephrostomy tube falls out, the patient should cover the site with a clean dressing and contact their healthcare provider immediately.