Transapical vs transfemoral aortic valve implantation: which procedure for which patient from the surgeon's point of view (2023)

introduction

Transcatheter aortic valve implantation (TAVI) has gained increasing acceptance for the treatment of patients with severe aortic stenosis (AS), particularly those with a higher risk profile. The procedure is performed in a variety of ways, however, the two main approaches are the transfemoral retrograde (TF) approach and the transapical anterograde (TA) approach. Currently, TAVI is indicated when there is a high risk, according to the latest statements from the European Society of Cardiology and the European Association of Cardiothoracic Surgery (1). The results of TAVI in patients at intermediate risk with a logistic EuroSCORE less than 20% or a Society of Thoracic Surgeons (STS) STS score between 4% and 8% are currently being evaluated in prospective randomized studies such as the SURTAVI study (TF CoreValve™ versus conventional surgery) and PARTNER 2 study (EdwardsSAPIEN-XT™ versus conventional surgery). Despite these advances in endovascular approaches, conventional surgery remains the standard for many patients and is associated with excellent outcomes. For example, in 2011 a German registry reported an all-cause mortality of just 3% in 11,500 patients who underwent conventional surgery for aortic valve disease (2).

Our common goal is to carry out the optimal therapy for the individual patient. This is essentially based on a low risk of intervention in combination with an immediate functional improvement and good long-term durability. Simplicity and safety usually lead to good acceptance by the cardiac team of physicians, mainly cardiologists and cardiac surgeons, for using these approaches. For the individual patient, the overall balance of risks, which cannot be determined by incision length alone, but must prioritize hard endpoints such as mortality and morbidity such as stroke, is extremely important. Therefore, an objective, informative pre-procedure discussion, tailored to each patient's unique risks and potential outcomes, is mandatory before choosing between open and percutaneous options. for the treatment of aortic valve disease.

Technical aspects

Since the introduction of TAVI into broad clinical practice, concurrent with the CE approval of the Corevalve™ and SAPIEN™ prostheses in 2008, these procedures have been performed on thousands of patients using standardized techniques. Both approaches - the retrograde TF and the anterograde AT approaches - have gained wide acceptance. Despite many similarities, there are still clear differences between the two types of procedures, as illustrated inTable 1.

In general, considering the different aspectsTable 1TA access may offer some potential benefits, despite the current disadvantage of requiring a mini-thoracotomy. Larger sheath diameters can be used with the TA approach resulting in less valve crimping required which can translate to longer service life. Solutions to improve paravalvular leakage can also be implemented in clinical practice through the TA approach (theoretically, these solutions require larger diameters to be delivered via the TA pathway). In addition, clinical trials evaluating percutaneous access and closure systems are forthcoming and will hopefully lead to further improvements and confidence in the antegrade TA technique.

literature results

Despite the various deployment options for TAVI, current practice seems to favor the TF approach as the first choice in many institutions. While not the only reason, the idea that the TF approach is less invasive seems to be the driving force behind this choice. Patients may be happier knowing that the procedure can be performed through a very small incision rather than a mini-thoracotomy; However, this should not be the deciding factor. Objective approval must also consider other factors related to the procedure, and therefore the TAVI team must prioritize the most challenging outcomes when discussing the best option with patients.

Some landmark studies, such as the US-PARTNER study, were conducted with a TF-first approach despite a lack of scientific evidence (3,4). Only after the TF approach was ruled out due to the patient's increased risk of severely atherosclerotic peripheral vessels did the patient switch to a TA approach. This bias is evident in the SOURCE and SOURCE-XT registries, as patients who received a SAPIEN™ or SAPIEN-XT™ valve using the TA approach had a significantly higher risk profile. Although speculative, the higher risk profile of these patients may have contributed to the higher procedural mortality in TA approaches. Therefore, the comparison of AT and TF techniques with the currently available literature must be carefully reviewed and evaluated for inconsistencies before any conclusions can be drawn.

In addition, some specific risks may not be captured by currently available rating systems. As seen in the PARTNER study, which used a TF-first strategy, potential differences between the TF and TA arms could not be documented in terms of different STS values ​​(3,4). Therefore, the conclusion “TF is less invasive” when comparing TF to TA TAVI cannot be supported by literature. The current practice of presenting different survival curves for TF and AT in patients with vastly different risk profiles on one slide should be done with caution or not at all.

There is a national database, the Canadian registry, that shows similar results at 2, 3, and 4 years after TF and TA TAVI. After combining the results from the multicenter study, the overall results of the TA were as good as those of the TF approach, despite a significantly higher risk profile in the cohort treated with the AT approach (5). However, the assignment of the patients to the various therapy options was not randomized.

Data from the Heart Center Leipzig came to similar conclusions. Patients receiving TA approaches generally have higher mean risk profiles and better outcomes than those treated with TA within the first four years. In addition, there is reason to believe that the TA approach could yield results similar to TAVI-TF implantation in similar patients. Unfortunately, direct and comprehensive data comparing data across national and international cohorts are not available, and prospective randomized trials evaluating all participants may not be feasible.

specific risks

There are specific risks to TAVI that differ significantly from the risks of conventional surgery. TAVI can be performed without cardiopulmonary bypass or cardiac arrest and is therefore minimally invasive. However, calcified native aortic valve leaflets remain in situ and can lead to various complications depending on the pathology of the individual patient. Paravalvular leaks or annular perforations can occur, and other screening mechanisms must be implemented to avoid these risks. The presence of a second-degree paravalvular leak (rated as 'mild' in the PARTNER study) is associated with reduced survival in patients with T-AVI, providing additional support for the establishment of screening mechanisms and improvements in methods of prevention of leaks offers (6,7).

Stroke is one of the complications, if not the most devastating, that can occur during TAVI. Many published studies describe stroke risks during TAVI, but there is no direct comparison. The results reported in the TA-TAVI series showed slightly lower stroke rates than those describing the TF approach. Common direct factors leading to stroke risk during any type of TAVI may be the use of balloon valvuloplasty and the valve implantation process. However, the antegrade valve implantation access modes “no aortic contact” versus retrograde passage through the aortic arch also play a role. There are currently no randomized studies. When commenting on the reported neurological results, we must also consider whether the study was reviewed and reviewed by a neurologist and whether the patients underwent post-procedural imaging and neurofunctional testing. Therefore, the comparability of some reports may be limited.

In addition, stroke rates 30 days after TAVI can be divided into "early" and "late" events. Consistent with our own experience, it appears that "early" events (in other words, a patient clearly suffers a stroke during the procedure) in the anterograde transapical approach are very rare, while "late" strokes (about 50% of all events) seem to be all Affect patients regardless of the chosen approach. The phenomenon of these “late” scams is not fully understood. Possibly, recurrence of atrial fibrillation could be a contributing factor, and it is possible, although speculative at this point, that more aggressive anticoagulation might help prevent subsequent neurological adverse events.

An interesting meta-analysis was recently published that included more than 10,000 patients and compared three patient groups: TF Corevalve™, TF Edwards SAPIEN™ and TA Edwards Sapien™ (8). The results of the meta-analysis show that the TF Corevalve™ (n=3226, mean LogisticsEuroscore 22%) had a stroke rate of 3.1±2.2%, the TFEdwards SAPIEN™ (n=1733, mean LogisticsEuroscore 26%) one had a stroke rate of 4.2±2.2% and the EdwardsSapien™ TA prosthesis (n=2482, mean logistic Euroscore 29%) had a stroke rate of 2.7±1.4% (8). Despite the potential limitations of each meta-analysis, the presented results are quite unequivocal and show that individual patients need to be informed about a possible increased stroke risk when planning a retrograde approach prior to TAVI.

Patients undergoing TAVI should also consider the risk of access-related morbidity, such as B. a vascular injury, are taken into account. The safety of the TA approach was demonstrated in the multi-center PREVAIL-TA study in 150 patients, of which only one patient (0.7%) experienced access-related complications (9).

perspectives

Looking ahead, more and more technical advances lead to the development of new devices as we understand the clinical pitfalls of current TAVI instruments and procedural approaches. Interestingly, many new devices are initially designed for the "simpler" TA access path. This can lead to advances in the benefits of the TA approach, such as: B. reduced crimping of the tissue flaps. This in turn can lead to greater structural integrity and longevity of the implanted device. In addition, new access and closure systems may enable safe percutaneous access through a TA incision, combining the benefits of a minimally invasive approach with those of an anterograde approach. The improved imaging methodology will further improve the visibility of devices, resulting in an even higher safety profile for procedures. The future lies in the comprehensive training of cardiologists and surgeons who carry out all therapies actively and together. This will lead to a new specialty of a structural cardiac interventionist to treat high-risk patients.

thanks

Disclosure:The authors declare no conflict of interest.

references

1. Vahanian A, Alfieri O, Al-Attar N, et al. Transcatheter valve implantation in patients with aortic stenosis: Statement of the European Association for Cardiothoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European Association for Percutaneous Cardiovascular Interventions (EAPCI). EUR Heart J 2008;29:1463-70.
2. Gummert JF, Funkat AK, Beckmann A, et al. Cardiac surgery in Germany 2010: a report commissioned by the German Society for Thoracic and Cardiovascular Surgery. Thorac Cardiovasc Surg 2011;59:259-67.
3. Leon MB, Smith CR, Mack M, et al. Transcatheter aortic valve implantation for aortic stenosis in patients who cannot be operated on. N Engl J Med 2010;363:1597-607.
4. Smith CR, Leon MB, Mack MJ and others. Transcatheter versus surgical aortic valve replacement in high-risk patients. NEngl J Med 2011;364:2187-98.
5. Rodés-Cabau J, Webb JG, Cheung A, et al. Percutaneous aortic valve implantation for the treatment of severe symptomatic aortic stenosis in patients at very high or prohibitive surgical risk: acute and late results from the Canadian multicenter experience. J Am Coll Cardiol 2010;55:1080-90.
6. Kodali SK, Williams MR, Smith CR, et al. Two-year results after transcatheter or surgical aortic valve replacement. N Engl J Med 2012;366:1686-95.
7. Abdel-Wahab M, Zahn R, Horack M et al. Aortic regurgitation after transcatheter aortic valve implantation: incidence and early outcome. Results from the German register of catheter-supported aortic valve interventions. Heart2011;97:899-906.
8. Eggebrecht H, Schmermund A, Voigtländer T, et al. Risk of stroke after transcatheter aortic valve implantation (TAVI): a published meta-analysis of 10,037 patients. EuroIntervention 2012;8:129-38.
9. Walther T, Thielmann M, Kempfert J, et al. PREVAILTRANSAPICAL: Multi-center study on transcatheter aortic valve implantation using the newly developed bioprosthesis (SAPIEN-XT) and delivery system (ASCENDRA-II). EurJ Cardiothorac Surg 2012;42:278-83.