PTBD Drain Internalization
Once a PTBD tract has matured (approximately 7-10 days after placement), the external drain is converted to internal drainage by advancing the catheter across the obstruction into the duodenum, allowing bile to drain internally into the bowel rather than externally into a collection bag. 1
Technical Procedure for Internalization
Perform cholangiography through the existing PTBD catheter 2-3 weeks after initial placement to confirm biliary tree patency, document resolution of obstruction, and verify tract maturation before attempting internalization. 1
The internalization technique involves advancing the existing catheter or placing a new internal-external drain across the site of previous obstruction into the duodenum, converting external drainage to internal anatomic drainage into the bowel. 2, 3
Internal-external drains allow bile to drain both externally (through side holes above the obstruction) and internally (through distal holes positioned in the duodenum), with the internal component being the therapeutic goal. 2, 4
The catheter is advanced over a guidewire through the biliary tree, across the ampulla, and into the duodenum under fluoroscopic guidance, ensuring proper positioning with side holes spanning from the intrahepatic ducts to the duodenum. 3
Timing Considerations
Standard tract maturation requires 3-6 weeks before catheter manipulation or removal, though internalization attempts may begin at 2-3 weeks if cholangiography confirms adequate decompression. 1
Patients with diabetes, ascites, long-term steroid therapy, or malnutrition require longer drainage periods (extending beyond the standard 3-6 weeks) as these conditions significantly impair tract maturation. 1
Alternative Internalization Strategies
When standard internalization across a tight stricture fails, conversion to endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) represents a rescue option, with technical success rates of 100% and clinical success rates of 81% in patients with malignant obstruction. 5
For patients with two transhepatic access tracts where only one has been successfully internalized, a captured microwire forced-buckle maneuver can internalize the second tract by capturing a wire from the external tract and forcing it through the internalized tract into the bowel. 2
Endoscopic rendezvous procedures using the percutaneous tract allow for combined percutaneous-endoscopic stent placement to restore bile duct continuity when direct internalization is technically challenging. 1
Post-Internalization Management
After successful internalization, the external portion of the catheter may be capped or removed entirely once repeat cholangiography confirms unobstructed internal bile flow and absence of leak. 1, 3
Internal-external drains in malignant obstruction typically require planned exchanges at median intervals of 45 days to maintain patency and prevent cholangitis, even after successful internalization. 4
Patients should have open-access follow-up to address complications promptly, as 56% of patients with internal-external drains experience complications requiring intervention, with 65% manageable on an outpatient basis. 4
Critical Pitfalls to Avoid
Do not attempt catheter manipulation or removal without confirmatory cholangiography demonstrating tract maturation and biliary patency, as premature removal dramatically increases bile leak risk. 1
Do not rely solely on visual drainage characteristics to determine readiness for internalization; objective imaging confirmation of obstruction resolution is mandatory. 1
Avoid high-pressure contrast injection during cholangiography, as this may cause cholangio-venous reflux and precipitate bacteremia or sepsis. 6
Recognize that internal drainage is associated with significantly less morbidity than prolonged external drainage, making internalization the preferred endpoint whenever technically feasible. 2, 3