Thrombus aspiration and in situ thrombolysis via a 6F Guidezilla catheter in elderly patients with high-risk pulmonary embolism: a case series of six patients

Background Systemic thrombolysis is often not an option for elderly patients with PE because of bleeding risk. Large-bore catheters (16F−24F) can injure fragile vessels. The 6F Guidezilla guide extension catheter, already used in coronary cases, offers a smaller-caliber choice for thrombus aspiration and local thrombolysis. We report six elderly patients with high-risk PE treated with this approach. Methods Six consecutive patients with intermediate-high or high-risk PE underwent thrombus aspiration and in situ thrombolysis through a 6F Guidezilla catheter (March 2024 to January 2026). Agents used: recombinant human prourokinase 15–30 mg or urokinase 2 million IU. All had contraindications to systemic thrombolysis. We collected baseline data, procedural metrics, Miller scores (pre/post), SpO₂, hemodynamics, complications, hospital stay, and 30-day outcomes. Results The mean age of the patients was 75.8 ± 4.6 years (range 70–81 years), with five patients aged ≥70 years. One patient presented with high-risk PE (shock), and the remaining five were classified as intermediate-high risk. The mean simplified Pulmonary Embolism Severity Index (sPESI) score was 2.7 ± 1.2. The mean Miller score decreased significantly from 18.0 ± 6.7 pre-procedure to 5.2 ± 3.6 post-procedure ( P < 0.05), with a mean clot clearance rate of 74.1% ± 15.2%. SpO₂ improved from 84.5% ± 5.0% pre-procedure to 97.2% ± 0.8% at 24 h post-procedure ( P < 0.01). The high-risk patient was successfully weaned off vasopressors within 24 h of the procedure. No major bleeding or procedure-related deaths occurred during hospitalization. The mean hospital stay was 7.8 ± 4.4 days, and no recurrent PE or death was observed within 30 days of follow-up. Conclusion The 6F Guidezilla catheter appears safe and effective for thrombus aspiration and in situ thrombolysis in elderly PE patients who cannot receive systemic thrombolysis. It achieves good clot clearance, quick clinical recovery, and few complications. When large-bore catheters are unavailable or too risky for elderly vessels, this technique is a practical alternative.