INTRODUCTION
Transcatheter aortic valve implantation (TAVI) has become a standard procedure in multiple centres for high risk patients with severe aortic stenosis. Elective femoro-femoral cardiopulmonary bypass (CPB) during transcatheter aortic valve implantation (TAVI) may make this procedure safe and reproducible in patients with severely depressed myocardial
function (ejection fraction [EF] <20%), in cardiogenic shock or with concomitant heart disease. However, the prognosis is grave for patients who are not candidates for conventional aortic valve replacement or TAVI.
And alternative is to perform TAVI on cardiopulmonary bypass (CPB). The use of CPB may represent a feasible therapeutic option for very high-risk patients with cardiogenic shock,
depressed left (LV) or right ventricular (RV) function or severe concomitant disease. In addition, previous heart surgery in this high-risk patient group will not increase the perioperative risk.
OBJECTIVE
Elective use of normothermic cardiopulmonary bypass (CPB) may reduce the risks associated with the transcatheter aortic valve implantation (TAVI) procedure in selected high-risk TAVI patients.
METHODS
Between September 2013 and May 2024, 389 consecutive patients underwent TAVI. Elective normothermic femoro-femoral cardio pulmonary bypass was used in 3 patients. Left ventricular ejection fraction was a mean of 20 % ± 5 % (range, 10-30%).
RESULTS
The device success rate was 99% in this study group. The median duration of CPB was 24mins (range, 25-35mins). In all patients with pulmonary hypertension combined with an enlarged right ventricle (RV), or with poor LVEF (mean LVEF: 20% ± 5% [range 10-30%]), CPB was used to prevent hemodynamic instability during valve deployment and to eliminate the adverse effects of possible ventricular fibrillation.
CONCLUSION
The use of Pre-operatively planned CPB may increase the safety of the TAVI procedure in patience with severely reduced heart function or in cardiogenic shock. Furthermore, transcatheter aortic valve implantation with cardiopulmonary bypass seems to provide better results than medical therapy or conventional aortic valve replacement in critically ill patients. The need for cardiopulmonary bypass emphasizes that the procedure should be performed only in cooperation between cardiologists and cardiac surgeons.
PATIENTS AND METHODS
Patients
TAVI was performed between September 2013 and May 2024 in 389 patients at Narayana Hrudayalaya Foundations, Bangalore. In total, 8 Patients got arrested and went on emergency CPB, 3 Patients underwent TAVI electively on CPB and 4 Patients went on emergency peripheral VA ECMO initiation.
ELECTIVE CARDIOPULMONARY BYPASS DURING TAVI
Criteria for patients undergoing elective CPB
Symptomatic severe aortic stenosis (AS) with metrics of valve anatomy, val ve hemodynamics, and hemodynamic consequences consistent with :
I. High-gradient AS
ii. Low-flow/low-gradient AS with reduced left ventricular ejection fraction (LVEF); or
iii. Low-gradient AS with normal LVEF or paradoxical low-flow severe AS
Aged patients with severely calcified AS.
Patients with aortic root height <5mm from the aortic annulus.
AIMS OF THE ELECTIVE USE OF CARDIOPULMONARY BYPASS FOR TRANSCATHETER AORTIC VALVE IMPLANTATION
We consider heart–lung machine to be a useful tool during TAVI. Therefore, our first-line strategy in patients with a small
distance between the coronary ostia and the aortic annulus or in patients with severe pulmonary hypertension is to place the connecting tubes on the table to save time should complications occur. In patients with markedly reduced LV function (i.e. LVEF <25%) or severe regurgitation of the atrioventricular valves, we prefer prophylactic cannulation of the femoral vessels without starting up CPB. If hemodynamic instability (which is refractory to high-dose catecholamine administration) occurs, the heart–lung machine can be started
within 1 s by simply removing the clamps on the connecting tubes. Our third strategy with valvuloplasty and valve deployment under a short duration of CPB is considered at our institution in patients with poor LV performance (LVEF 10–20%), in cardiogenic shock and with decompensated right-sided heart failure with enlarged RV. Primary use of CPB instead of its secondary use on an emergency basis may provide superior results, especially due to the fact that the progression of rapid pacing into ventricular fibrillation is often
diffcult to manage.
The aim of the CPB Is to minimize potential complications. Therefore, it is used to stabilize the patients’ condition, to achieve haemodynamic stability during TAVI, and to avoid the possible need for manual cardiopulmonary resuscitation if ventricular fibrillation should occur during rapid pacing for balloon valvuloplasty and during valve deployment in patients with severely depressed myocardial function. In patients with cardiogenic shock, CPB is used for additional myocardial recovery of the unloaded heart after the new transcatheter valve is deployed.
CANNULATION FOR ELECTIVE CARDIOPULMONARY BYPASS
The use of normothermic femoro-femoral CPB was routinely considered to provide a higher safety level during the procedure, and especially to obviate manual cardiopulmonary resuscitation if ventricular fibrillation occurs during TAVI.In the case of severe calcification, the axillary artery was cannulated. In the case of the transfemoral approach for TAVI, the artery of better quality was used for the TAVI procedure and the other site for CPB cannulation.
TECHNICAL CONSIDERATION OF THE TRANSCATHETER AORTIC VALVE IMPLANTATION PROCEDURE DURING ELECTIVE CARDIOPULMONARY BYPASS
The Introduction of the guidewires and introducers through the native valve or through the LV apex (in the case of transapical TAVI) into the LV was performed while a slight filling of the heart was achieved by reducing the CPB drainage to maintain LV ejection and facilitate initial passage of the guide-wire through the stenotic aortic valve. If complete unloading of the heart was possible, balloon dilatation of the native valve and valve deployment was performed without rapid pacing to avoid possible ventricular fibrillation. If complete drainage and
unloading of the heart was not possible, rapid pacing was used for balloon valvuloplasty and valve release, and the LV was drained as much as possible to prevent heart distension and ventricular fibrillation. The prophylactic trans-femoral placement of an intra-aortic balloon pump (IABP) was considered in patients with poor LVEF and/or in cardiogenic shock to secure greater safety and haemodynamic stability during the immediate postoperative course. Then the patient was weaned off CPB.
In regressed LV patients (EF <25%), when the valve deployed under higher pacing rates(180-200bpm) can cause: Stroke, Arrhythmias, Cardiac arrest, Dissection, LVOT obstruction. When undergoing electively on CPB, the heart will be decompressed during the valve deployment by lowering the flows or by undergoing TCA for a minute without the use of pacing will prevent the above mentioned mishaps.
PATIENT DATA:
Common diagnosis: Severe AS, Dilated chambers, LVEF 15- 25%, Pulmonary Hypertension, Mild – Moderate MR.
RESULTS
Femoro-Femoral CPB was established. The valve deployed with low CPB flow to decompress the heart & for proper positioning of the valve. Weaned off CPB support. Post-operatively, Good LVF noted, Patient hemodynamically stable and neurologically stable. Patient discharged with less POD of 2-3 days.
EMERGENCY ECMO DURING TAVI
Criteria for patients undergoing emergency ECMO
– Severe calcied AS
– Valve dislodgment
– Aortic Rupture
– Reduced Biventricular Function
– Hypotension
– Desaturation
– Cardiac arrest
– Pericardial effusion(depending on score)
In this case..
ECMO is not a treatment, It’s just a bridge to recovery.
PATIENT DATA:
Common diagnosis: Reduced LVEF, Hypotension, Desaturation, Cardiac arrest.
DISCUSSION
In this article, we show that the use of CPB during TAVI allows the procedure to be performed with greater safety in patients with advanced heart failure. An elective femoro-femoral bypass was used in 4 patients. Our standard institutional policy is to consider the use of elective femoro-femoral CPB in patients with severe cardiogenic shock, poor left ventricular function (LVEF, 10%–20%), or both.
Nevertheless, no literature as yet exists presenting experience with the elective and urgent use of CPB during TAVI. CPB is rarely necessary for TAVI, but it is a prerequisite for the procedure to have the heart-lung machine ready to use in the operating room, and it is an important part of the safety net, although not all patients placed on CPB during the procedure need the support. Nevertheless, its elective use increases the safety in critically ill patients to maintain hemodynamic stability during the phases of rapid pacing and to prevent manual cardiopulmonary resuscitation, because the postoperative course of these patients is unfavorable.
We have shown that the emergency ECMO initiation rather than elective CPB during TAVI has poor outcomes in critically ill patients (advanced heart failure patients). CPB is rarely necessary for TAVI. Nevertheless, its use allows the procedure to be performed safely in patients with severely depressed left ventricular function (ejection fraction <20%) with or without additional severe mitral valve regurgitation, coronary artery disease, severe pulmonary hypertension with an enlarged right ventricle, or unstable hemodynamics. These
patients might develop ventricular brillation during or immediately after the cessation of rapid pacing for balloon dilatation of the native valve or valve deployment.
CONCLUSION
Therefore, for patients with unstable haemodynamics, severely depressed heart function or concomitant heart disease, TAVI combined with the use of CPB seems to provide much better results than medical treatment or conventional aortic valve replacement, which is associated with relatively high operative mortality in these patients. The use of heart-lung machine may increase safety and yield cceptable outcomes in this very high-risk patient group.
The use of pre-op planned CPB may increase the safety of the TAVI procedure in patients with severely reduced Heart function. The use of CPB during TAVI helps in decompression of the heart and helps in proper placement and deployment of the valve. The mortality rates are much higher in patients who underwent emergency ECMO initiation than pre-planned elective CPB. Hence, Elective CPB is preferably good for patients undergoing TAVI with reduced Heart functions.
REFERENCES
1. Thorsten Drews MD, Miralem Pasic MD, PhD, Semih Buz MD, Giuseppe D’Ancona MD, PhD, Alexander Mladenow MD, Roland Hetzer MD, PhD, Axel Unbehaun MD; Elective femoro-femoral cardiopulmonary bypass during transcatheter aortic valve implantation: Auseful tool
2. Thorsten Drews, Miralem Pasic, Semih Buz, Stephan Dreysse, Christoph Klein, Marian Kukucka, Alexander Mladenow, Roland Hetzer, Axel Unbehaun Author Notes; Elective use of femoro-femoral cardiopulmonary bypass during transcatheter aortic valve implantation
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5. Takumi Osawa, Hiroaki Watabe , Tomoya Hoshi , and Masaki Ieda; Emergency transcatheter aortic valve Implantation with a self-expandable valve under Extracorporeal membrane oxygenation for Cardiogenic shock due to bicuspid aortic Stenosis: a case report
6. Michael Seco BMedSc a b c, Paul Forrest MBChB FANZCA a d, Simon A. Jackson BSc (Hons) e, Gonzalo Martinez MD f I, Sarah Andvik b, Paul G. Bannon MBBS PhD FRACS a b c, Martin Ng MBBS PhD FRACP a f, John F. Fraser MBBS PhD FRCAFCICM g, Michael K. Wilson MBBS FRACS b c h, Michael P. MBBS PhD report
Connect with author
prakash.p.v.s@narayanahealth.org