Outcomes of Transcatheter Aortic Valve Implantation in Management of Severe Symptomatic Aortic Stenosis

Severe symptomatic aortic stenosis in elderly patients represents a surgical challenge for cardiac surgeons due to heavy calcifications and associated comorbidities. Such conditions usually are associated with dramatic intra and postoperative complications leading to many cases being declined for open surgical replacement. Many treatment modalities were described including trans-catheter valvotomy but with only temporary improvements and high rates of recurrence.

Transcatheter Aortic Valve Implantation (TAVI) has offered an alternative solution to such cases in which open surgery is deemed too risky or prohibited. Percutaneous Heart Valves (PHV) implantations have been experimented on animals since the early 1990s. Yet the first human case was not reported till 2002, in which a percutaneously implanted heart valve (PHV) composed of 3 bovine pericardial leaflets mounted within a balloon-expandable stent was developed and implanted through the antegrade trans-septal approach in a patient presenting with severe calcific aortic stenosis associated with many noncardiac comorbidities including leg ischaemia. Despite Patient's death after 17 weeks due to noncardiac causes, his follow-up showed significant improvement of left ventricle (LV) function and aortic valve area after implantation of the percutaneous valve.

This case was followed by several single-center and small multicenter registries and series that included inoperable or very-high-risk patients, which were associated with promising results that confirmed the feasibility of TAVI.

Many approaches are used for TAVI with the transfemoral approach being the primary option. Abnormalities of the iliofemoral anatomy have led to the emergence of other approaches including transapical, subclavian, axillary, and transaortic routes. Potential advantages of such approaches would be the avoidance of using large catheters though the iliofemoral system, aortic arch, ascending aorta, and aortic valve. Yet, their main disadvantage would be the need for general anaesthesia.

As any surgical procedure, TAVI carries some risk of complications, major vascular injuries, stroke, conduction abnormalities, myocardial infarction, coronary obstruction and acute kidney injury have been reported. Although, careful planning, patient selection, perioperative workup and individualised approach choice play an important role in avoiding such problems.