Understanding the Inari FlowTriever System: A Comprehensive Overview for Pulmonary Embolism Treatment
Pulmonary embolism (PE) represents a significant cardiovascular challenge, characterized by the obstruction of pulmonary arteries by blood clots, often originating from deep vein thrombosis. The clinical spectrum of PE ranges from asymptomatic cases to life-threatening scenarios, necessitating effective and timely intervention. In recent years, advancements in medical technology have introduced innovative solutions for PE management, among which the Inari FlowTriever system stands out as a purpose-built mechanical thrombectomy device.
What is the Inari FlowTriever System?
The Inari FlowTriever system is a pioneering medical device specifically designed for the non-surgical removal of emboli and thrombi from blood vessels, with a primary indication for the treatment of acute pulmonary embolism. It holds the distinction of being the first mechanical thrombectomy system to receive FDA 510(k) clearance for PE treatment. The system's core objective is to achieve rapid thrombus removal and immediate symptom improvement in patients suffering from this acute condition [1].
Mechanism of Action: Large-Bore Aspiration and Mechanical Thrombectomy
The FlowTriever system operates on a principle of large-bore aspiration and mechanical retrieval, distinguishing it from traditional approaches that often rely on thrombolytic drugs. The procedure typically involves inserting a guiding catheter into a vein, commonly in the groin area, and advancing it to the pulmonary arteries. Once positioned, the system's specialized catheters are deployed to engage and remove the clot.
The primary mechanism involves the use of **Triever Aspiration Catheters** (e.g., Triever16, Triever20, and Triever24) which are designed for high trackability to navigate complex and tortuous anatomy within the vasculature. These catheters facilitate rapid, large-bore aspiration, creating a vacuum to disrupt and extract the thrombus. Concurrently, the **FlowTriever Catheters** work to capture and remove larger clot burdens. The system is also complemented by the **FlowSaver Blood Return System**, which allows for autologous blood transfusion, minimizing blood loss during the procedure.
This mechanical approach offers a significant advantage by enabling immediate clot removal without the need for thrombolytic agents, which carry an inherent risk of bleeding complications. The ability to remove large clots in a single session further enhances its clinical utility [1].
Clinical Performance and Evidence: The FLASH Registry
The efficacy and safety of the Inari FlowTriever system are supported by robust clinical data, most notably from the **FLASH Registry** (NCT03761173). This registry represents the largest prospective interventional dataset for the treatment of pulmonary embolism, providing comprehensive insights into the system's performance in a real-world setting. The FLASH Registry has demonstrated unmatched procedural safety and favorable patient outcomes.
Key findings from the FLASH Registry include:
- **Acute PE Patients Registered:** Over 800 acute PE patients were registered in the study [1].
- **Major Adverse Events (MAEs):** A remarkably low incidence of major adverse events, reported at 1.8% [1].
- **All-Cause Mortality:** An all-cause mortality rate of less than 1.0% at 30-day follow-up (n=734) [1].
Furthermore, the FLASH data highlights that thrombus removal with the FlowTriever system leads to immediate improvements in cardiac function, acute symptom relief, and sustained long-term outcomes. At 6 months post-procedure, the registry reported 95.1% normal right ventricular (RV) function (n=247) and 90.1% mild or absent dyspnea (n=343). The incidence of chronic thromboembolic pulmonary hypertension (CTEPH) at 6 months was also low, at 1.0% (n=581) [2]. These results underscore the system's ability to not only address the immediate threat of PE but also to contribute to improved long-term patient quality of life.
Benefits of the FlowTriever System
The Inari FlowTriever system offers several compelling benefits for both patients and healthcare providers:
- **Minimally Invasive:** The procedure is performed percutaneously, avoiding the need for open surgery.
- **Rapid Thrombus Removal:** The large-bore aspiration technology allows for quick and efficient removal of significant clot burdens.
- **Immediate Symptom Improvement:** Patients often experience rapid relief from PE-related symptoms due to restored blood flow.
- **Reduced Bleeding Risk:** By eliminating the need for thrombolytic drugs, the system significantly lowers the risk of major bleeding complications.
- **Comprehensive Clot Management:** The system is designed to handle large clots effectively, which may be challenging for other devices.
Indications for Use
The FlowTriever retrieval/aspiration system is indicated for the non-surgical removal of emboli and thrombi from blood vessels. It is intended for use in the peripheral vasculature and specifically for the treatment of pulmonary embolism. Additionally, Triever catheters are intended for use in treating clot in transit in the right atrium, though not in conjunction with FlowTriever catheters. The system's components, such as the Triever20 Curve, can be used coaxially within the Triever24 for similar indications. The FlowSaver blood return system is utilized with Triever catheters for autologous blood transfusion [1].
Conclusion
The Inari FlowTriever system represents a significant advancement in the treatment of acute pulmonary embolism. Its innovative design, focusing on large-bore aspiration and mechanical thrombectomy, provides a safe and effective alternative to traditional thrombolytic therapies. Supported by strong clinical evidence from the FLASH Registry, the FlowTriever system offers rapid thrombus removal, immediate symptom improvement, and favorable long-term outcomes, ultimately enhancing patient care in the challenging landscape of PE management.
**Disclaimer:** This article is intended for informational and scientific purposes only and does not constitute medical advice. Healthcare professionals should refer to the complete Instructions for Use, Indications for Use, Warnings, Precautions, Possible Adverse Effects, and Contraindications prior to using the product. Patients should consult with their physician for any medical concerns.
References
[1] Toma C, Jaber WA, Weinberg D, et al. Acute Outcomes for the Full US Cohort of the FLASH Mechanical Thrombectomy Registry in Pulmonary Embolism. EuroIntervention. 2023;18(14):1201-1212. [https://www.inarimedical.com/flowtriever-system](https://www.inarimedical.com/flowtriever-system) [2] Khandhar S et al. Longer-Term Outcomes Following Mechanical Thrombectomy for Intermediate- and High-risk Pulmonary Embolism: 6-Month FLASH Registry Results. JSCAI 2023;2(4):101000. [https://www.inarimedical.com/flowtriever-system](https://www.inarimedical.com/flowtriever-system)