Imaging for a Leaking Nephrostomy Tube

Initial Imaging Approach

The American College of Radiology recommends injecting water-soluble contrast material directly through the nephrostomy tube under fluoroscopic guidance to identify the exact location and mechanism of leakage 1, 2
Fluoroscopy provides immediate assessment of tube patency, position within the collecting system, and integrity of the drainage pathway, allowing real-time visualization of contrast extravasation around the tube, tube malposition, tube dislodgement, or collecting system injury 1, 2, 3

Bedside ultrasound can be used as an adjunct to rapidly assess for hydronephrosis, perirenal fluid collections, or hematoma formation, but cannot definitively evaluate tube position or the drainage pathway 1
Doppler ultrasound may help identify vascular complications if persistent hematuria accompanies the leak 3

Fever, sepsis, or signs of infection mandate immediate imaging (preferably CT with IV contrast) as sepsis is the most serious complication of nephrostomy tube problems and can be fatal 3
Persistent or recurrent gross hematuria after the initial post-placement period suggests vascular injury (pseudoaneurysm, arteriovenous fistula) requiring CT angiography or conventional angiography 2, 3

Always use water-soluble (not barium) contrast for nephrostogram to avoid peritoneal contamination if significant extravasation exists 4, 5
If the tube is completely dislodged and cannot be accessed for contrast injection, proceed directly to CT with IV contrast and delayed excretory phase imaging to assess the collecting system 6, 7

If imaging shows vascular injury, angiography with selective embolization is the treatment of choice for pseudoaneurysms, arteriovenous fistulas, or active extravasation 2, 3
Urgent tube replacement is required, preferably under ultrasound and fluoroscopic guidance, if the nephrostogram shows complete dislodgement 1, 3