Percutaneous Transhepatic Biliary Drainage: The Parallel Technique for Undilated Systems with Perihepatic Fluid
The parallel technique for percutaneous transhepatic biliary drainage (PTBD) in an undilated system with perihepatic fluid involves accessing a peripheral bile duct through direct puncture or with assistance of a previously placed catheter, with special considerations to avoid complications in this challenging scenario. 1, 2
Technical Approach for Undilated Systems
Pre-Procedure Considerations
- Assess coagulation parameters prior to the procedure, as PTBD is contraindicated in patients with uncorrected coagulopathy due to increased bleeding risk (approximately 2.5% of cases) 3
- Evaluate the perihepatic fluid carefully, as moderate to massive ascites is a relative contraindication for PTBD 3
- Consider ERCP as first-line approach when feasible, as PTBD is generally reserved for patients who have failed ERCP or who have difficult anatomy 1, 4
The Parallel Technique
- The parallel technique involves accessing a peripheral bile duct (fourth order or smaller branch) through direct puncture 2
- In cases with perihepatic fluid, the transhepatic approach is preferred over transperitoneal to reduce the risk of bile leak and allow for longer drain placement 1
- When direct puncture is challenging, the technique can be modified by using a previously placed catheter to facilitate access to the target duct 2
Advanced Modifications
- For difficult cases, a nitinol Goose Neck snare can be passed through an intraductal catheter to facilitate peripheral duct puncture, which has been shown to be the fastest access method 2
- End-to-end contact between the tips of instruments at the ampulla's orifice may be used in a modified rendezvous technique to establish access 5
Technical Challenges and Considerations
Challenges in Undilated Systems with Perihepatic Fluid
- Patients with nondilated intrahepatic bile ducts have significantly higher complication rates (14.5%) compared to those with dilated ducts (6.9%) 6
- The presence of perihepatic fluid increases the risk of bile leak and biliary peritonitis, making the transhepatic approach essential 1
- Injection of contrast under pressure should be avoided as this may lead to cholangio-venous reflux and exacerbate septicemia 1
Post-Procedure Management
- Percutaneous cholecystostomy catheter should be removed between 4 and 6 weeks after placement, if a cholangiogram performed 2–3 weeks after the procedure demonstrates biliary tree patency 1
- Patients with diabetes, ascites, long-term steroid therapy, or malnutrition may require longer drain placement to ensure tract maturation 1
- Perform a cholangiography via the drain before withdrawal to ensure absence of leak or obstructed cystic duct 1
Complications and Their Management
Potential Complications
- PTBD-related complications occur in approximately 9% of patients, with major complications in 4% 6
- Complications include bile duct leak, biliary peritonitis, portal or parenchymal vessel injury, bleeding, catheter dislodgement, and infection 1
- Post-PTBD cholangitis occurs in about 35% of cases, particularly with drainage lasting >30 days and with external-internal type drains 7
Management of Complications
- For post-procedural cholangitis, appropriate antibiotics should be administered within 1 hour of diagnosis in severe cases, or within 6 hours in less severe cases 1
- Intrahepatic abscesses should be treated with percutaneous drainage 8
- Symptomatic or infected bilomas should be managed with percutaneous drainage 8
Efficacy and Outcomes
- PTBD has a technical success rate of approximately 97%, with equal success rates in patients with dilated and nondilated bile ducts 6
- In patients with postsurgical biliary leaks and nondilated ducts, PTBD has shown an 88% success rate in healing fistulas within an average of 31 days 7
- PTBD is effective for both temporary decompression prior to surgery and as a palliative method in advanced malignancy 9