A Tech News article authored by Khalil Khalil, MD, Division of Cardiac Surgery, Department of Surgery, Université de Montréal, Montreal, Quebec, Canada, and Jessica Forcillo, MD, Department of Cardiac Surgery, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Quebec.
Right-sided infective endocarditis (RSIE) presents a unique clinical challenge associated with intravenous (IV) drug use, central venous catheters, and other predisposing factors. The standard treatment approach involves the combination of antimicrobial treatment and surgical therapy, if necessary. However, in high-risk or marginal patients with large vegetations, surgery can be prohibitive and IV antimicrobial therapy might be insufficient, leading to embolic complications, persistent bacteremia, and hemodynamic instability. Recognizing the need for advancements, the AngioVac system emerges as a minimally invasive aspiration tool, offering a new dimension in our therapeutic options for RSIE.
The AngioVac system, developed by AngioDynamics, Inc., is a catheter-based device initially designed for percutaneous intravascular thrombectomy and embolectomy. Approved by the US Food and Drug Association in 2014, it has been used to aspirate iliocaval, pulmonary, upper extremity, and right-sided heart chamber thrombi. The system operates on a veno-venous bypass mechanism, featuring a closed-loop circuit connected to a venous drainage and reinfusion cannulas (Figure 1).
This temporary bypass diverts blood from the right atrium, undergoes extracorporeal filtration, and is then returned to the patient. The procedure begins with percutaneous access, generally via the femoral or jugular veins, under fluoroscopic, echocardiographic (transesophageal or intracardiac) guidance. Using controlled negative pressure, the system aspirates blood and unwanted material while simultaneously filtering it, thus preventing embolization of debris to peripheral vessels during reinfusion.
This real-time filtration capability is a critical feature that enhances the safety and efficacy of the technique. The reinfused blood ensures minimal hemodynamic impact during the procedure.
In recent years, the AngioVac system has gained attention for its potential role in the management of RSIE, especially in patients unresponsive to IV antibiotics and deemed high-risk for surgery, including IV drug users for whom a tricuspid valve replacement is an undesirable option. Despite limited long-term data, early experiences have shown promising results.
A systematic review and meta-analysis of 301 patients from 44 studies revealed a procedural success rate of 89.2% (have a residual vegetation size (RVS) <50% without serious procedural complications) with clinical success achieved in 79.1% of the patients (defined as a composite of RVS<50%, in-hospital survival, absence of recurrent bacteremia, and valve function not requiring further intervention). Vegetation removal >50% was achieved in 90%, and bacteremia clearance in 82.5% of patients.
New cases series and single-center retrospective studies have also shown positive preliminary results, showcasing the system’s potential effectiveness in different clinical scenarios, such as pacemaker lead-related endocarditis.
Despite successful and promising primary results, the use of the AngioVac system has its own potential complications and adverse events. Mhanna et al. showed in their meta-analysis that 11% of patients required conversion to open surgery. Complications include vegetation disruption leading to pulmonary embolization with infection potential, with Abubakar et al. showing a 34-55% risk of septic pulmonary embolism in patients with vegetations >1cm, predisposing them to further infection, mainly refractory sepsis and pulmonary abscesses.
Vascular access complications, such as bleeding, were reported by Worku et al. at 12%, mainly including hematoma and retroperitoneal bleeding. Another potential complication mainly attributed to the device’s suctioning properties is tricuspid valve injury and worsening of tricuspid regurgitation (TR). Studies by George, Fallon, and Kiani demonstrated worsening of TR post-procedure when compared to pre-procedure.
While continued research and long-term studies are imperative to validate the initial findings and to solidify its role in the treatment of RSIE, the AngioVac system represents a leap forward in the pursuit of minimally invasive, effective, and patient-centric solutions, and a valuable tool in the hands of clinicians striving to optimize patients’ outcomes.
With standard antibiotic therapy remaining paramount, AngioVac has the potential to become an integrated treatment option in the complex management of RSIE patients with high surgical risk and those with large vegetations (even though optimal size remains unclear, several studies consider vegetations >2cm, especially those causing embolic events).
AngioVac also holds promise as a complementary therapy for persistent bacteremia associated with biofilm-protected vegetations, potentially enhancing treatment efficacy through mechanical debridement and improved antibiotic penetration. In other cases, in which surgery is still needed, it can serve as a valuable bridge, potentially debulking the vegetation and improving hemodynamic stability, thus paving the way to definitive surgery at a later stage.