26 August, 2024

Understanding the Role of Awake Peripheral V-A ECMO in High-Risk TAVR Procedures: A Detailed Case Study

 

 

Transcatheter Aortic Valve Replacement (TAVR) has revolutionized the treatment of severe aortic stenosis, especially for patients who are not candidates for traditional open-heart surgery. However, TAVR procedures can be extremely high-risk, particularly in patients with multiple comorbidities. In such cases, innovative strategies like the use of awake Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation (pV-A ECMO) can provide critical support. This blog explores the role of pV-A ECMO in managing a complex case of high-risk TAVR.

Case Overview: A High-Risk Patient Profile

The patient in focus is an 82-year-old gentleman who presented with progressive dyspnea (classified as NYHA-III) and angina. His symptoms had been worsening over the past six months, culminating in an emergency room visit due to severe chest pain, orthopnea, and flu-like symptoms. Initial stabilization was achieved through non-invasive ventilation (NIV), diuretics, and supportive medications. However, further investigations revealed a challenging clinical scenario:

• Severe Calcific Aortic Stenosis: Tricuspid valve gradient of 79 mmHg and aortic valve area (AVA) of 0.6 cm².
• Recurrent NSTEMI and Heart Failure: Acute exacerbation of chronic heart failure with deteriorating left ventricular (LV) function.
• Respiratory Complications: Worsening viral pneumonia with superimposed bacterial infection, leading to poor lung reserve.
• Acute Kidney Injury (AKI): Elevated serum creatinine and urea levels, indicative of significant renal impairment.
• Significant Coronary Artery Disease: High calcium score with severe left main (LM) and left anterior descending (LAD) artery disease, along with mild right coronary artery (RCA) involvement.

Given his frailty, advanced age, and the complexity of his condition, the patient was deemed extremely high-risk for any surgical or percutaneous intervention. The heart team at Apollo Main Hospitals, Chennai, faced the challenge of balancing the need for intervention against the potential risks.

The Decision: Awake Prophylactic V-A ECMO Supported TAVR

Considering the patient’s precarious condition, the multidisciplinary heart team decided to proceed with a TAVR procedure under the support of prophylactic awake pV-A ECMO. This approach was chosen for several reasons:

• Hemodynamic Stability: pV-A ECMO provides circulatory and pulmonary support, which is crucial during high-risk procedures. It maintains stable blood flow and oxygenation even in cases of hemodynamic compromise.
• Avoidance of General Anesthesia: Keeping the patient awake reduces the risks associated with intubation and mechanical ventilation, which can be particularly hazardous in patients with poor lung reserve and severe pneumonia.
• Support During Concomitant Procedures: The patient required not only TAVR but also high-risk percutaneous coronary intervention (PCI) for LM and LAD disease. ECMO support allowed these interventions to be performed simultaneously, minimizing procedural risks.

The Procedure: TAVR and High-Risk PCI with ECMO Support

The patient was taken to the cath lab, where the following steps were executed:

1. Initiation of ECMO: Peripheral V-A ECMO was initiated through the left femoral artery and vein. This provided immediate circulatory and pulmonary support, ensuring hemodynamic stability throughout the procedure.
2. Percutaneous Coronary Intervention (PCI): The heart team first addressed the significant coronary artery disease. Balloon predilation was performed on the left main and LAD arteries, followed by the deployment of drug-eluting stents (DES). Despite challenges such as hemodynamic instability during left coronary artery (LCA) cannulation, ECMO support ensured the patient remained stable.
3. TAVR Procedure: A balloon-expandable aortic valve was successfully implanted via the right femoral artery. The valve was accurately positioned and expanded without complications.
4. Withdrawal of ECMO: Following the successful implantation of the valve, ECMO support was gradually weaned off, and the patient was decannulated. Both the left femoral artery and vein access sites were closed using ProGlide devices.

Post-Procedure Recovery and Outcomes

Post-procedure, the patient was closely monitored in the intensive care unit (ICU). His recovery was marked by several key milestones:

• Stabilization of Heart Function: Echocardiography performed at discharge showed a normally functioning bioprosthetic valve with a mean gradient of 8 mmHg and no paravalvular leak. Left ventricular function was adequate, with no regional wall motion abnormalities (RWMA).
• Resolution of Respiratory and Renal Complications: The patient’s pneumonia gradually improved with intensive care, including antibiotics and antivirals. His renal function also began to recover, with a decrease in serum creatinine and urea levels.
• Improvement in General Condition: By day 9, the patient was shifted from the ICU to a regular ward, where he continued to receive chest physiotherapy and rehabilitation. Continuous monitoring ensured that any signs of deterioration were promptly addressed.

The Benefits of Awake V-A ECMO in High-Risk TAVR

This case highlights several key advantages of using awake pV-A ECMO in high-risk TAVR procedures:

• Improved Hemodynamic Stability: ECMO provides a safety net, allowing the heart team to manage hemodynamic fluctuations during complex interventions.
• Avoidance of Mechanical Ventilation: By keeping the patient awake, the risks associated with general anesthesia and mechanical ventilation are minimized, particularly in patients with poor lung function.
• Facilitates Concomitant Procedures: ECMO support allows for the simultaneous performance of multiple high-risk procedures, reducing the overall time the patient spends under intervention and potentially lowering the risk of complications.
• Reduced Length of Stay: By stabilizing the patient during the procedure and facilitating quicker recovery, ECMO may contribute to shorter ICU and hospital stays, ultimately reducing healthcare costs.

The Future: Need for Further Research

While the outcome in this case was favorable, it underscores the need for further research into the use of prophylactic awake V-A ECMO in high-risk TAVR procedures. Randomized controlled trials (RCTs) are necessary to establish the safety, efficacy, and cost-effectiveness of this approach across different patient populations.

In conclusion, the use of awake peripheral V-A ECMO represents a promising strategy for managing high-risk patients undergoing TAVR and other complex cardiovascular procedures. As the field of interventional cardiology continues to evolve, innovations like these will play a crucial role in improving patient outcomes and expanding the possibilities for treating previously inoperable conditions.