Abstract
Background.
Transcatheter aortic valve implantation (TAVI) is increasingly recognized as an alternative to surgery for patients with severe, symptomatic aortic stenosis and high or prohibitive operative risk. Despite prospective evidence that TAVI can be performed with acceptable 30-day mortality, the potential for vascular, neurologic or cardiac complications exists.
Method.
One hundred and sixty-three balloon-expandable TAVIs were performed between November 2005 and February 2008 at St. Paul’s Hospital, Vancouver, Canada. Valves were implanted using a transarterial (n=110) or transpical approach (n=53). Clinical and echocardiographic data was prospectively collected.
Results.
Overall 30-day mortality rate was 11.0% in this selected high risk population but mortality decreased by 50% in the second half of this cohort. Current systems require a large sheath (22 to 24 Fr) potentially injurious to femoral and iliac arteries. Unplanned percutaneous (n=2) or surgical (n=11) interventions were performed in 14 patients to treat peripheral vascular complications. Temporary endovascular balloon occlusion can provide hemostasis while definitive treatment is implemented. Acute complications associated with apical access include bleeding and tamponade. Intra-procedural deaths occurred in 1.2% of patients due to arterial perforation (n=1) and apical hemorrhage (n=1). Stroke rate was 4.3%. Positioning errors can result in significant paravalvular regurgitation, mitral valve injury (n=1) and valve embolization (n = 7). Paravalvular leak can be reduced by redilation of an under-expanded prosthesis or implantation of a second valve to extend the sealing cuff. Cases of embolization were all satisfactorily managed with re-expansion of the prosthesis distally in the aorta. Coronary ostial obstruction by a bulky leaflet was confirmed in 1 patient. Permanent pacemakers were implanted in 9 patients (5.5%) due to new heart block.
Conclusion.
This early TAVI experience demonstrated the potential for a variety of potential complications. However as experience and knowledge increased over time the rate of adverse events appeared to fall. Careful screening, technological advances and greater experience will allow for safer procedures.