وصف
A "sternotomy," in which the chest is surgically divided (opened) for the procedure, is typically required for valve replacement. All of the chest bones can remain in place when the TAVR or TAVI procedures are performed through extremely small incisions. There are two methods that can be used. Using a minimally invasive surgical approach with a small chest incision and entering through a large artery in the chest or through the tip of the left ventricle (the apex), which is known as the transapical approach, or through the femoral artery (large artery in the groyne), the transfemoral approach, which does not require a surgical incision in the chest.
ملخص
- TAVI (Transcatheter Aortic Valve Replacement) offers a less invasive alternative to surgical aortic valve replacement (SAVR), particularly for patients with severe symptomatic aortic stenosis who are at high surgical risk due to age, comorbidities, or prior conditions. TAVI avoids open-heart surgery and is often preferred for patients deemed unsuitable for SAVR. Guidelines, like the 2017 recommendations, initially favored SAVR for low-risk patients, but TAVI is gaining acceptance even in lower-risk categories.
- The development of TAVI began with balloon aortic valvuloplasty in 1985. It evolved with animal trials in 2000 and was first performed on a human in 2002. Edwards Lifesciences manufactured and introduced the first commercially available TAVI valve in 2004. Subsequent partner trials demonstrated positive outcomes, leading to over 400,000 cases performed worldwide.
- TAVI devices are primarily categorized into balloon-expandable and self-expandable valves. Balloon-expandable valves, pioneered by Edwards Lifesciences (e.g., Sapien XT, Sapien 3), require balloon inflation for deployment. Self-expandable valves, like those from Medtronic (e.g., CoreValve, Evolut Pro), gradually expand upon release. Indian companies such as Meril and Hydra also manufacture balloon-expandable and self-expandable devices, respectively.
- Clinical trials, including Partner 1, 2, and 3, have significantly influenced TAVI's adoption. These trials assessed TAVI's effectiveness compared to SAVR in different risk categories. Partner 1 focused on high-risk patients, Partner 2 on intermediate-risk, and Partner 3 on low-risk patients. Results have shown TAVI to be non-inferior, and in some cases superior, to SAVR in reducing stroke, re-hospitalization, and overall mortality.
- Pre-TAVI evaluation is crucial. It includes assessing symptoms, disease severity via echocardiography, and evaluating comorbidities. A comprehensive anatomical and clinical assessment is essential to determine suitability for TAVI. CT angiography is critical to evaluate iliofemoral access, aortic root dimensions, coronary height, and calcification patterns.
- Valve size selection depends on accurate measurements of the aortic annulus and root. CT angiography is often preferred over transesophageal echocardiography for sizing accuracy. Valve selection considerations include the risk of annular rupture, coronary obstruction, the need for valve-in-valve procedures, and the degree of aortic calcification.
- Contraindications for TAVI include a life expectancy of less than 12 months, the presence of severe valve disease, inadequate annulus size, active endocarditis, a high risk of coronary ostium obstruction, or severe asymmetric valve calcification. Potential immediate complications include complete heart block, major strokes, vascular complications, paravalvular leaks, and valve embolization. Late complications can include conduction system disorders, infective endocarditis, valve thrombosis, and valve degeneration.
- The TAVI procedure involves accessing the femoral artery, crossing the aortic valve with a guidewire, and deploying the selected valve. Balloon-expandable valves are positioned and expanded using a balloon catheter. Self-expandable valves are released gradually. Valve-in-valve procedures involve implanting a new valve within a previously implanted surgical valve that has degenerated.
- Experiences shared indicated a center performing around 80 to 85 TAVI procedures, primarily on patients over 75 years of age. Complications reported were relatively low. Evolving indications suggest a broader role for TAVI, including its use in low-risk patients and those with asymptomatic severe aortic stenosis.
نموذج شهادة
حول المتحدثين
Dr. Ranga Reddy
Cardiologist, Apollo Hospitals
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