Catheter-Directed Thrombolysis Protocols for Deep Venous Thrombosis of the Lower Extremities—A Systematic Review and Meta-analysis

Objective To summarize characteristics, complications, and success rates of different catheter-directed thrombolysis (CDT) protocols for the treatment of lower extremity deep venous thrombosis (LE-DVT). Methods A systematic review using electronic databases (MEDLINE, Scopus, and Web of Science) was performed to identify randomized controlled trials and observational studies related to LE-DVT treated with CDT. A random-effects model meta-analysis was performed to obtain the pooled proportions of early complications, postthrombotic syndrome (PTS), and venous patency. Results Forty-six studies met the inclusion criteria reporting 49 protocols (n = 3,028 participants). In studies that addressed the thrombus location (n = 37), LE-DVT had iliofemoral involvement in 90 ± 23% of the cases. Only four series described CDT as the sole intervention for LE-DVT, while 47% received additional thrombectomy (manual, surgical, aspiration, or pharmacomechanical), and 89% used stenting. Definition of venogram success was highly variable, being the Venous Registry Index the most used method (n = 19). Among those, the minimal thrombolysis rate (<50% lysed thrombus) was 0 to 53%, partial thrombolysis (50–90% lysis) was 10 to 71%, and complete thrombolysis (90–100%) was 0 to 88%. Pooled outcomes were 8.7% (95% confidence interval [CI]: 6.6–10.7) for minor bleeding, 1.2% (95% CI: 0.8–1.7%) for major bleeding, 1.1% (95% CI: 0.6–1.6) for pulmonary embolism, and 0.6% (95% CI: 0.3–0.9) for death. Pooled incidences of PTS and of venous patency at up to 1 year of follow-up were 17.6% (95% CI: 11.8–23.4) and 77.5% (95% CI: 68.1–86.9), respectively. Conclusion Assessment of the evidence is hampered by the heterogeneity of protocols, which may be reflected in the variation of PTS rates. Despite this, CDT is a low-risk treatment for LE-DVT.