Adverse Events After Percutaneous Transhepatic Biliary Drainage: A 10-Year Retrospective Analysis
Executive Summary
This briefing document synthesizes the findings of a 10-year retrospective clinical study (2010–2020) conducted at Northwestern University. The study analyzed 2,310 percutaneous transhepatic biliary drainage (PTBD) procedures performed on 449 patients to determine adverse event (AE) rates, profiles, and risk factors.
Critical Takeaways:
Overall Adverse Event Rate: The study documented 745 AEs across 2,310 procedures, representing a 32.2% AE rate.
Primary Complications: The three most frequent AEs were pericatheter bile leaks (44.4% of total AEs), catheter occlusion (14.7%), and drain dislodgement (13.8%).
Risk Factors: Malignant biliary obstruction and right-sided biliary drains were significantly associated with higher AE rates.
Protective Factors: Intraprocedural cholangioplasty was identified as a significant protective factor, associated with a decreased AE rate for both initial and subsequent procedures.
Severity Profile: The vast majority of AEs (86.7%) were classified as Society of Interventional Radiology (SIR) Grade 1, requiring minimal intervention.
Study Overview and Methodology
The analysis provides a comprehensive look at institutional experiences with PTBD, a procedure typically used when endoscopic retrograde cholangiopancreatography (ERCP) fails or is technically unfeasible.
Scope and Population
Timeframe: April 2, 2010, to April 20, 2020.
Total Patients: 449 consecutive patients.
Total Procedures: 2,310 interventions.
Initial Drain Placements: 455 (including 66 with cholangioplasty).
Drain Exchanges: 1,855 (including 202 with cholangioplasty).
Laterality: 1,164 right-sided, 966 left-sided, and 180 bilateral drains.
Etiology: 61% of patients had malignant obstructions; 39% had benign etiologies.
Statistical Approach
The study utilized a generalized estimating equation (GEE) model to assess multivariate risk factors, accounting for the fact that multiple procedures were often performed on the same patient (mean of 5.1 procedures per patient).
Profile of Adverse Events (AEs)
The study recorded 745 total AEs. While the technical success rate for PTBD is high (typically exceeding 90%), the procedural risk remains notable.
Common Adverse Events
SIR Severity Classification
Adverse events were graded according to the SIR system, with the following distribution:
Grade 1 (Minor): 86.72% (444 events)
Grade 2: 8.79% (45 events)
Grade 3: 1.95% (10 events)
Grade 4: 1.56% (8 events)
Grade 5 (Death): 0.98% (5 events)
Risk and Protective Factor Analysis
The study identified several key variables that significantly impacted the likelihood of an AE occurring.
Significant Risk Factors
Malignant Biliary Obstruction:
Associated with a higher AE rate (29.8%) compared to benign obstruction (17.6%).
Odds Ratio (OR): 1.57 (P = .006).
Potential causes include immunosuppression, malnutrition, and faster disease progression.
Right-Sided Drain Access:
Associated with an increased overall AE rate for both initial and total procedures.
OR: 1.43 (P = .017).
Increased risk may be due to the intercostal approach, where the drain is anchored between ribs, potentially leading to acute angles or motion-related issues during respiration.
Significant Protective Factor
Intraprocedural Cholangioplasty:
Associated with a decreased AE rate for initial drains (OR: 0.48, P = .022) and overall procedures (OR: 0.63, P = .009).
It is theorized that cholangioplasty helps maintain an appropriate pressure gradient and antegrade flow, reducing the "path of least resistance" for bile to leak around the catheter.
Non-Significant Factors
Drain Size/Type: The study found no significant association between drain caliber (>10 F) or drain type (internal-external vs. external only) and AE rates.
Patient Demographics: Age and sex were not significant predictors of AEs.
Detailed Clinical Complications
Infectious Complications
Sepsis: 38 instances were recorded. Nine cases required ICU care, all of which occurred following initial drain placement.
Malignancy Link: 74% of sepsis cases occurred in patients with malignant obstructions.
Prophylaxis: All patients in the study received prophylactic antibiotics, which likely contributed to the relatively low rates of sepsis (1.6%) and cholangitis (1.7%) compared to some earlier literature.
Hemorrhagic Events
Bleeding occurred in 1.1% of procedures (26 instances).
Major Bleeding: 21 instances (0.9% of procedures) required embolization.
Minor Bleeding: 5 instances (0.2% of procedures) were managed conservatively.
Stent and Catheter Issues
Dislodgement: This was the most common cause of pericatheter leakage. The dislodgement rate was 4.5% overall.
Metal Stents: Among 156 metal stents placed, distal migration occurred in 1.2% of cases, and occlusion due to tumor ingrowth occurred in 5.1%.
Jailed Ducts: Reported in 7.6% of metal stent cases, primarily resulting in elevated alkaline phosphatase and jaundice.
Tract Seeding
Tract seeding was a rare complication, occurring in 0.7% of total AEs (0.2% of total procedures). All five cases occurred in patients with malignancy, with seeding appearing in the chest wall, abdominal wall/peritoneum, or intrahepatic locations between 17 and 143 days post-procedure.
Conclusions and Clinical Implications
The study concludes that while PTBD is a high-impact procedure with high technical success, it is associated with a notable volume of minor AEs, particularly mechanical catheter issues.
Key findings for clinical practice include:
Patient Selection: Clinicians should be aware of the higher risk profile for patients with malignant obstructions and those requiring right-sided access.
Procedural Technique: The use of intraprocedural cholangioplasty appears to significantly reduce the risk of subsequent adverse events.
Follow-up Care: The study noted a downward trend in AE rates over time, potentially linked to the increased involvement of nurse practitioners in drain education and patient monitoring.
Antibiotic Prophylaxis: The results support the continued use of prophylactic antibiotics for all PTBD patients to mitigate infectious risks.
