In interventional medicine and surgical procedures, PCN stands for Percutaneous Nephrostomy, a procedure focusing on the urinary system. This minimally invasive technique provides a temporary or long-term solution to drain the kidney when the normal pathway for urine flow is blocked. The procedure is performed by specialists such as interventional radiologists or urologists to protect kidney function and resolve complications from obstruction.
What is Percutaneous Nephrostomy
Percutaneous nephrostomy creates a direct path from the kidney to the outside of the body through the skin. The urinary system normally moves urine from the kidneys, through the ureters, to the bladder. When this natural drainage system is compromised, a PCN tube is placed to bypass the blockage.
The term “percutaneous” means “through the skin,” highlighting the minimally invasive approach. A small, flexible catheter is inserted into the renal pelvis, the funnel-shaped area where urine collects. This catheter allows urine to drain directly into an external collection bag, relieving pressure and preventing damage to the kidney tissue. The tube is often a pigtail catheter, named for the curled end that sits inside the kidney to prevent accidental dislodgement.
When is a PCN Necessary
The most frequent reason for PCN placement is to relieve a blockage in the urinary tract, known as obstructive uropathy. When a ureter is obstructed, urine builds up in the kidney, causing swelling called hydronephrosis. Unrelieved hydronephrosis can quickly lead to irreversible kidney damage, making timely drainage a priority.
Obstruction can be caused by various factors, including kidney stones lodged in the ureter or renal pelvis, or external pressure from tumors, such as gynecological or colorectal cancers. Strictures, which are areas of scarring or narrowing in the ureter, can also impede urine flow. A blockage combined with a kidney infection (pyonephrosis or urosepsis) is a life-threatening emergency requiring immediate drainage.
Beyond simple drainage, a PCN can also be used as a temporary measure to divert urine flow, allowing an injury or surgical repair of the ureter to heal completely. It also serves as an access route for other therapeutic procedures, such as percutaneous nephrolithotomy (PCNL), which involves entering the kidney through the skin to remove large kidney stones.
The PCN Procedure Explained
The placement of a percutaneous nephrostomy tube is a short, minimally invasive procedure, typically performed in an interventional radiology suite. The patient is usually positioned on their stomach or side and receives local anesthesia at the insertion site, often accompanied by moderate sedation. Imaging guidance, usually ultrasound and fluoroscopy (real-time X-ray), is used to precisely locate the kidney and the internal collecting system.
A small incision is made in the skin. A fine needle is then carefully inserted through the back muscles and into the renal pelvis under continuous imaging guidance. A specialized guidewire is threaded through the needle and into the kidney’s collecting system, establishing a secure path.
The tract created by the needle is progressively widened using a series of dilators passed over the guidewire. This creates space to accommodate the final drainage catheter, typically 8 to 14 French in diameter. The nephrostomy tube is advanced over the guidewire, and its coiled tip is secured inside the renal pelvis. The tube is then connected to an external drainage bag and secured to the skin with sutures or a specialized locking device.
Caring for a Nephrostomy Tube
Caring for a nephrostomy tube requires meticulous attention to the insertion site, tubing, and drainage bag to prevent infection and displacement. The dressing must be kept clean and dry, typically changed every two to three days, or immediately if soiled. Proper hand hygiene is paramount before and after handling the tube.
Patients should gently clean the skin around the tube using mild soap and water, ensuring the area is completely dry before applying a fresh, sterile dressing. The drainage bag must always be positioned lower than the kidney to ensure gravity assists urine flow and prevent backflow. The bag should be emptied regularly (when two-thirds full) to prevent the weight from pulling on the tube.
The tube must be secured to the body with tape or a securing device, creating a small loop to prevent accidental tugging or kinking. Patients should seek immediate medical attention if they notice signs of complications:
- Fever over 101°F.
- New or worsening pain in the flank.
- Significant bleeding around the tube site.
- Tube dislodgement (falling out).
- The tube stops draining urine entirely, which may indicate a blockage.
PCN tubes are often temporary, remaining in place for days or weeks, but they can be necessary for months or years in cases of chronic obstruction. For long-term use, the catheter must be exchanged by a healthcare provider every two to three months to maintain patency and prevent mineral deposits. While showering is permissible, patients must avoid soaking the tube in still water; baths, hot tubs, and swimming are prohibited.