Transapical Aortic Valve Implantation Without Angiography: Proof of Concept

Comparison of transesophageal and transthoracic echocardiography under moderate sedation for guiding transcatheter aortic valve replacement

The optimal periprocedural imaging strategy during transcathether aortic valve replacement (TAVR) performed under moderate sedation is debated. Transthoracic echocardiography (TTE) provides suboptimal views due to poorer resolution and patient positioning, whereas use of transesophageal echocardiography (TEE) under moderate sedation is not widely utilized. The aim of our study was to compare the value of TTE in comparison with TEE guidance under moderate sedation during TAVR. The study population included 144 consecutive patients (mean age 83 ± 11 years, 78 (54%) females) who had TAVR under moderate sedation using either a TTE (n = 96) or TEE (n = 48). We compared procedural outcomes using propensity score matching. There were no significant inter-group differences in age, sex, ejection fraction, aortic valve area, pressure gradients, creatinine or type of valve used. The procedural time was significantly shorter in the TEE group (P < 0.001) and associated with a lower need for periprocedural aortograms (7.7 ± 1.9 vs 8.2 ± 1.9, P = 0.022) and a lower occurrence of acute kidney injury (1 vs 11, P = 0.047). The 1:1 propensity score matching also showed a lower procedural time (P = 0.032), number of aortograms (P = 0.014) and a trend toward lower acute kidney injury in the TEE group (P = 0.077). TAVR guidance using TEE is associated with a lower fluoroscopic time, a lower need for additional aortograms and trend in lower occurrence of post-TAVR acute kidney injury.

Transfemoral versus transapical approach for transcatheter aortic valve implantation: hospital outcome and risk factor analysis

Background

Transcatheter aortic valve implantation is indicated in high-risk patients with aortic stenosis. We compared the clinical outcome of 180 consecutive patients who underwent transapical (TA) and transfemoral (TF) procedures in a single centre.

Methods

Ninety consecutive TA (TA-group) and 90 consecutive TF (TF-group) were performed from 2009 to 2014. Clinical variables were prospectively collected and retrospectively analysed for hospital outcomes and to identify risk factors for hospital mortality, vascular complications and stroke.

Results

Mean age was 80 ± 8.5 and 83 ± 8.4 years, in the TA and TF-group, respectively. TA-group presented higher prevalence of comorbidities: more vascular disease (79% vs 22%, p < 0.001), chronic pulmonary disease (32% vs 10%, p < 0.001), previous vascular surgery (14% vs 4%, p = 0.039), coronary disease (60% vs 40%, p = 0.007), and previous cardiac surgery (28% vs 17%, p = 0.073). Logistic Euroscore was 36 ± 15% in the TA-group and 25 ± 14% in the TF-group (p < 0.001), but hospital mortality was similar (TA:9%, TF:10%, p = 0.799). Access-related vascular complications occurred more often in transfemoral patients (TA:3%, TF:11%, p = 0.081) while major bleeding (TA:3%, TF:4%, p = 1) and stroke (TA:2%, TF:3%, p = 1) were equally distributed. Postoperative renal failure and dialysis were associated with impaired neurological outcome (p = 0.035 and p = 0.020, respectively). Mild to severe paravalvular leak was more prevalent in transfemoral patients (TA:5%, TF:25%, p < 0.001).

Conclusions

In our experience, the TA and TF-group presented different risk profiles but mortality rate and adverse neurological outcome had a similar incidence. The transfemoral approach carried more vascular complications and paravalvular leaks but last-generation devices will improve this outcome.

Augmented Reality System for Ultrasound Guidance of Transcatheter Aortic Valve Implantation

OBJECTIVE

Transcatheter aortic valve implantation (TAVI) relies on fluoroscopy and nephrotoxic contrast medium for valve deployment. We propose an alternative guidance system using augmented reality (AR) and transesophageal echocardiography (TEE) to guide TAVI deployment. The goals of this study were to determine how consistently the aortic valve annulus is defined from TEE using different aortic valve landmarks and to compare AR guidance with fluoroscopic guidance of TAVI deployment in an aortic root model.

METHODS

Magnetic tracking sensors were integrated into the TAVI catheter and TEE probe, allowing these tools to be displayed in an AR environment. Variability in identifying aortic valve commissures and cuspal nadirs was assessed using TEE aortic root images. To compare AR guidance of TAVI deployment with fluoroscopic guidance, a TAVI stent was deployed 10 times in the aortic root model using each of the two guidance systems.

RESULTS

Commissures and nadirs were both investigated as features for defining the valve annulus in the AR guidance system. The commissures were identified more consistently than the nadirs, with intraobserver variability of 2.2 and 3.8 mm, respectively, and interobserver variability of 3.3 and 4.7 mm, respectively. The precision of TAVI deployment using fluoroscopic guidance was 3.4 mm, whereas the precision of AR guidance was 2.9 mm, and its overall accuracy was 3.4 mm. This indicates that both have similar performance.

CONCLUSIONS

Aortic valve commissures can be identified more reliably than cuspal nadirs from TEE. The AR guidance system achieved similar deployment accuracy to that of fluoroscopy while eliminating the use and consequences of nephrotoxic contrast and radiation.

Transcathether Valve Replacement and Valve Repair

Transcatheter aortic valve replacement for treatment of aortic stenosis has now become an accepted alternative to surgical valve replacement for some patients. In addition, transcatheter mitral valve repair is also routinely used in high surgical risk patients with mitral regurgitation. Other transcatheter procedures are in rapid development. The current review attempts to summarize the procedures and echocardiographic imaging used for transcatheter valve replacement or valve repair.

Periprocedural considerations of transcatheter aortic valve implantation for anesthesiologists

Transcatheter aortic valve replacement (TAVR) is rapidly gaining popularity as a viable option in the management of patients with symptomatic aortic stenosis (AS) and high risk for open surgical intervention. TAVR soon expanding its indications from "high-risk" group of patients to those with "intermediate-risk". As an anesthesiologist; understanding the procedure and the challenges inherent to it is of utmost importance, in order to implement optimal care for this generally frail population undergoing a rather novel procedure. Cardiac anesthesiologists generally play a pivotal role in the perioperative care of the patients, and therefore they should be fully familiar with the circumstances occurring surrounding the procedure. Along with increasing experience and technical developments for TAVR, the procedure time becomes shorter. Due to this improvement in the procedure time, more and more anesthesiologists feel comfortable in using monitored anesthesia care with moderate sedation for patients undergoing TAVR. A number of complications could arise during the procedure needing rapid diagnoses and occasionally conversion to general anesthesia. This review focuses on the periprocedural anesthetic considerations for TAVR.

Phantom study of an ultrasound guidance system for transcatheter aortic valve implantation

A guidance system using transesophageal echocardiography and magnetic tracking is presented which avoids the use of nephrotoxic contrast agents and ionizing radiation required for traditional fluoroscopically guided procedures. The aortic valve is identified in tracked biplane transesophageal echocardiography and used to guide stent deployment in a mixed reality environment. Additionally, a transapical delivery tool with intracardiac echocardiography capable of monitoring stent deployment was created. This system resulted in a deployment depth error of 3.4mm in a phantom. This was further improved to 2.3mm with the custom-made delivery tool. In comparison, the variability in deployment depth for traditional fluoroscopic guidance was estimated at 3.4mm.

Successful transfemoral aortic Edwards(®) SAPIEN(®) bioprosthesis implantation without using iodinated contrast media in a woman with severe allergy to contrast agent

Severe anaphylactoid reaction after the use of iodinated contrast media are rare but can contraindicate the use of contrast agent. It was the case of a 53-year-old woman suffering from symptomatic severe aortic stenosis, recused for cardiac surgery because of deleterious effects of chest-wall irradiation, with porcelain aorta. We decided to implant a 23-mm Edwards(®) SAPIEN(®) transcatheter aortic valve via a femoral route without using any contrast media. The implantation was successful after surgical approach of the femoral artery, transesophageal echocardiography guiding, and localization of native leaflets and coronary trunk with catheters. Immediate and one month post-interventional follow-up was favorable and echocardiography showed a good functioning of the aortic bioprosthesis. Although conventional angiography is the best way to visualize the good positioning of the valve before deployment, our case suggests that, in special situations, transfemoral implantation of an Edwards(®) SAPIEN(®) aortic bioprosthesis is feasible without any contrast injection.

A systematic review of transapical aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) through a transapical approach (TAAVI) for severe aortic stenosis becomes the procedure of choice in cases where patients have peripheral artery disease and unfeasible access due to excessive atherosclerotic disease of the iliofemoral vessels and aorta. The present systematic review aimed to assess the safety, success rate, clinical outcomes, hemodynamic outcomes, and survival benefits of TAAVI.

METHODS

Electronic searches were performed in 6 databases from January 2000 to February 2012. The primary end points included feasibility and safety. Other end points included echocardiographic findings, functional class improvement, and survival.

RESULTS

After applying the inclusion and exclusion criteria, 48 out of 154 shortlisted potentially relevant articles were selected for assessment. Of these, 26 studies from 24 centers including total number of 2,807 patients were included for appraisal and data extraction. The current evidence on TAAVI for aortic stenosis is limited to observational studies. Successful TAAVI implantation occurred in >90% of patients. On average, the procedure took between 64 to 154 minutes to complete. The incidence of major adverse events included 30-day mortality (4.7-20.8%); cerebrovascular accident (0-16.3%); major tachyarrhythmia (0-48.8%); bradyarrhythmia requiring permanent pacemaker insertion (0-18.7%); cardiac tamponade (0-11%); major bleeding (1-17%); myocardial infarction (0-6%); aortic dissection/rupture (0-5%); moderate to severe paravalvular leak (0.7-24%); cardiopulmonary bypass support (0-15%); conversion to surgery (0-9.5%); and valve-in-valve implantation (0.6-8%). Mean aortic valve area improved from 0.4-0.7 cm(2) before TAAVI to 1.4-2.1 cm(2) after TAAVI. The peak pressure gradient across the aortic valve decreased from >70 mmHg to <20 mmHg after TAAVI. One-year survival ranged from 49.3% to 82% and the 3-year survival was 58% in 2 series.

CONCLUSIONS

TAAVI appears to be feasible with a reasonable safety and efficacy portfolio. Randomised controlled trials are required to compare transapical vs. transfemoral TAVI when both techniques are equally feasible.

EACTS day in the new EACTS House

There is no doubt that the European Association for Cardio-Thoracic Surgery is a success story. In 2011, we celebrated the 25th anniversary of this professional organization. In 2012, we will celebrate the 25th anniversary of the European Journal of Cardio-Thoracic Surgery. In addition, two other journals have been initiated, Interactive CardioVascular and Thoracic Surgery and the Multimedia Manual of Cardio-Thoracic Surgery, and all of them can be accessed through CTSnet (www.ctsnet.org). The most recent development was the birth of EACTS House, and it was to celebrate the official opening of EACTS House on 10 February 2011, that we held the second Strategic meeting, 'EACTS in the Future'. On this occasion, the EACTS council and delegates of the EACTS Domains (Domain of Thoracic Disease, Domain of Vascular Disease, Domain of Congenital Cardiac Disease and Domain of Adult Cardiac Disease) came together with representative thoracic and cardio-vascular surgeons from North America, Asia and BRICS countries as well as senior managers from industry in order to decide where to go from there. As a basis for starting the discussions, a sector analysis of the activities of the Department of Cardio-Vascular Surgery at CHUV in Lausanne, Switzerland was performed in order to identify the trends in the activities of our group of surgeons by pulling the consolidated data for the period running from 1 January 1995 to 31 December 2010. Interestingly enough, the most frequent procedures like coronary artery bypass graft and valve repair/replacement did not increase despite a growing programme. In our setting, the compensation came mainly from vascular surgery and mechanical circulatory support. These data have to be put in perspective by the reports provided by the EACTS domain chairs in order to identify the challenges and opportunities for the future development of our specialties.

Modified 'dumbbell' technique: a simple and intuitive method to position balloon-expandable stent valves

Intraoperative cardiac imaging plays a key role during transcatheter aortic valve replacement. In recent years, new techniques and new tools for improved image quality and virtual navigation have been proposed, in order to simplify and standardize stent valve positioning and implantation. But routine performance of the new techniques may require major economic investments or specific knowledge and skills and, for this reason, they may not be accessible to the majority of cardiac centres involved in transcatheter valve replacement projects. Additionally, they still require injections of contrast medium to obtain computed images. Therefore, we have developed and describe here a very simple and intuitive method of positioning balloon-expandable stent valves, which represents the evolution of the 'dumbbell' technique for echocardiography-guided transcatheter valve replacement without angiography. This method, based on the partial inflation of the balloon catheter during positioning, traps the crimped valve in the aortic valve orifice and, consequently, very near to the ideal landing zone. It does not require specific echocardiographic knowledge; it does not require angiographies that increase the risk of postoperative kidney failure in elderly patients, and it can be also performed in centres not equipped with a hybrid operating room.

[Transcatheter aortic valve replacement: when should it be used in aortic stenosis?]

30% of patients with significant aortic stenosis are not considered for operative aortic valve replacement because of the high perioperative risk. An alternative catheter based option for these patients is the transcatheter aortic valve replacement (TAVI). In general, there are two approaches for TAVI: transfemoral and transapical. Transfemoral aortic valve replacement is performed by transcatheter replacement of an aortic valve via the femoral arteries. Transapical valve replacement is achieved by transcatheter implantation via the fifth intercostal space. The most common complications are vessel injuries, bleeding complications, new onset of AV-block, development of paravalvular insufficiency, acute kidney injury, stroke and TIA. The first long-term observations suggest positive results. First clinical trials in a high-risk population show a promising outcome. Therefore TAVI offers a reasonable therapy option for patients with high perioperative risk. Further long-term clinical trials are still pending.

Multimodality imaging throughout transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a novel, less-invasive technique used to treat selected patients with severe aortic valve stenosis with a high surgical risk. Noninvasive imaging before, during and after the procedure is of the utmost importance in this minimally invasive procedure. Screening of the patient and sizing of the aortic root by echocardiography and multislice computed tomography is of great importance to ensure success of the TAVI procedure. Echocardiography and fluoroscopy are essential during the procedure. During follow-up of the patients, echocardiography is important to evaluate the prosthesis function, durability and integrity. Additionally, multislice computed tomography and MRI might be helpful in the follow-up of selected cases. This article outlines the evolving role of multimodality imaging throughout TAVI in patients with severe aortic valve stenosis. It describes, in a stepwise approach, how multimodality imaging by echocardiography, angiography, multislice computed tomography and MRI enhances the TAVI procedure.

Intracardiac echocardiography: a new guiding tool for transcatheter aortic valve replacement

BACKGROUND

Echocardiography has been debated as an adjunct for transcatheter aortic valve replacement (TAVR). The aim of this prospective study was to comparatively evaluate intraprocedural guidance using intracardiac echocardiography (ICE) and transesophageal echocardiography (TEE).

METHODS

Fifty high-risk patients with severe aortic stenosis scheduled for TAVR were randomized to either guidance using ICE (group 1; n = 25) or monitoring using TEE (group 2; n = 25).

RESULTS

In contrast to TEE, ICE allowed continuous monitoring. The need for probe repositioning during the procedure was much lower in group 1 (0.1 ± 0.3 vs 5.7 ± 0.7 maneuvers, P < .001). Compared with TEE, the transcaval intracardiac echocardiographic view provided higher coaxiality with the ascending aorta expressed as the length of ascending aorta depicted (4.9 ± 1.2 vs 6.1 ± 1.2 cm, P = .003). Both coronary ostia were more frequently visualized in group 1 (18 vs 2 cases, P < .001). ICE-derived annular measurements were correlated closely with preinterventional readings on TEE (n = 25, r(2) = 0.90, P < .001). TEE underestimated intraprocedural pressure gradients in comparison with preinterventional measurements (mean difference, -10.2 ± 11.1 mm Hg; n = 11, P = .012), but ICE did not (mean difference, -0.3 ± 14.1 mm Hg; n = 25, P = .913). ICE and TEE detected newly grown thrombi (2 vs 1 case). Severe complications (e.g., annular dissection, pericardial effusion) were not observed.

CONCLUSIONS

ICE, which is compatible with sedation and local anesthesia, can be considered an alternative to TEE for intraprocedural guidance during TAVR. It also seems to match the required work flow during TAVR better than TEE.

Successful combined minimally invasive direct coronary artery bypass and transapical aortic valve implantation

Transapical aortic valve implantation is indicated in high-risk patients with aortic stenosis and peripheral vascular disease requiring aortic valve replacement. Minimally invasive direct coronary artery bypass grafting is also a valid, minimally invasive option for myocardial revascularization in patients with critical stenosis on the anterior descending coronary artery. Both procedures are performed through a left minithoracotomy, without cardiopulmonary bypass, aortic cross-clamping, and cardioplegic arrest. We describe a successful combined transapical aortic valve implantation and minimally invasive direct coronary bypass in a high-risk patient with left anterior descending coronary artery occlusion and severe aortic valve stenosis.

Cardiac CT: practical approach to integrate appropriate indications in daily practice

Recent advances in CT technologies had significantly improved the clinical utility of cardiac CT. Major efforts have been made to optimize the image quality, standardize protocols and limit the radiation exposure. Rapid progress in post-processing tools dedicated not only to the coronary artery assessment but also to the cardiac cavities, valves and veins extended applications of cardiac CT. This potential might be however used optimally considering the current appropriate indications for use as well as the current technical imitations. Coronary artery disease and related ischemic cardiomyopathy remain the major applications of cardiac CT and at the same time the most complex one. Integration of a specific knowledge is mandatory for optimal use in this area for asymptomatic as for symptomatic patients, with a specific regards to patient with acute chest pain. This review aimed to propose a practical approach to implement appropriate indications in our routine practice. Emerging indications and future direction are also discussed. Adequate preparation of the patient, training of physicians, and the multidisciplinary interaction between actors are the key of successful implementation of cardiac CT in daily practice.

Usefulness of TEE as the primary imaging technique to guide transcatheter transapical aortic valve implantation

OBJECTIVES

The aim of this study was to: 1) determine the usefulness of transesophageal echocardiography (TEE) as the primary technique to guide transapical (TA) transcatheter aortic valve implantation (TAVI); and 2) to compare TEE with angiography as the primary imaging modality for TA-TAVI guidance.

BACKGROUND

TEE has been routinely used as an adjunct to angiography during TA-TAVI procedures, but very few data exist on the use of TEE as the primary imaging technique guiding TA-TAVI.

METHODS

One hundred consecutive high-risk patients (mean age 79 ± 9 years, mean logistic EuroSCORE: 25.8 ± 17.6%) who underwent TA-TAVI in our center were included. The Edwards valve was used in all cases, and all procedures were performed in an operating room without hybrid facilities. The TA-TAVI was primarily guided by angiography in the first 25 patients (A-TAVI group) and by TEE in the last 75 patients (TEE-TAVI group). Procedural, 30-day, and follow-up results were evaluated.

RESULTS

No differences were observed between groups at baseline except for a higher (p = 0.001) prevalence of moderate or severe mitral regurgitation in the TEE-TAVI group. The procedure was successful in 97.3% and 100% of the patients in the TEE-TAVI and A-TAVI groups, respectively (p = 1.0), and a lower contrast volume was used in the TEE-TAVI group (12 [5 to 20] ml vs. 40 [20 to 50] ml, p < 0.0001). There were no differences between groups in the occurrence of valve malposition needing a second valve (TEE-TAVI: 5.3%; A-TAVI: 4%; p = 1.0) or valve embolization (TEE-TAVI: 1.3%; A-TAVI: 4%; p = 0.44). The results regarding post-procedural valve hemodynamic status and aortic regurgitation were similar between groups. The survival rates at 30-day and 1-year follow-up were 87% and 75% in the TEE-group and 88% and 84% in the A-TAVI group, respectively (log-rank = 0.49).

CONCLUSIONS

TEE-TAVI was associated with similar acute and midterm results as A-TAVI and significantly reduced contrast media use during the procedures. These results suggest the feasibility and safety of performing TA-TAVI procedures in an operating room without hybrid facilities, but larger studies are needed to confirm these findings.

Risk of acute kidney injury after minimally invasive transapical aortic valve implantation in 270 patients

OBJECTIVE

Contrast agent is a potential risk factor for acute kidney injury (AKI). Little is known about the incidence of contrast-induced nephropathy (CIN) after trans-apical aortic valve implantation (TA-AVI) and on the impact of contrast exposure during preoperative computed tomography (CT) scan and cardiac catheterization.

METHODS

A total of 270 consecutive high-risk patients received TA-AVI for symptomatic aortic valve stenosis during a 3-year period. Different preoperative, peri-procedural, and postoperative variables were analyzed by uni- and multivariate logistic regression concerning incidence of early (<7 days) AKI and need for renal replacement therapy (RRT). Nine patients on chronic preoperative dialysis were excluded.

RESULTS

Mean age was 82 ± 5.8 years, 71% were female. LogEuroSCORE (European System for Cardiac Operative Risk Evaluation) and STS Score were 31.4 ± 15.6% and 12.1 ± 7.4%, respectively. Preoperative estimated glomerular filtration rate (eGFR) <60 ml min(-1) was present in 35.2%. CT scan and cardiac catheterization within 7 days before TA-AVI were performed in 43.7% and 20.3% of the patients and were associated with a mean contrast-agent exposition of 110 ± 21 ml for CT scans and 91 ± 65 ml for cardiac catheterization. Regarding the postoperative renal outcome, an improved or at least stable eGFR was seen in more than 50% of the patients. Intra-operative contrast-agent application was 99 ± 64 ml and correlated significantly to the development of postoperative AKI and need for RRT (p=0.013 and p=0.003). Postoperative RRT was required in 15.7%. Chronic renal insufficiency (odds ratio (OR)=6.8, p=0.025) and number of blood transfusions (OR=8.8, p=0.009) were independent risk factors for RRT. Postoperative AKI occurred in 16.1% and intra-operative contrast-agent burden >99 ml (OR=2.3, p=0.038), new thrombocytopenia (OR=4.4, p=0.005) and pathological leucocyte count (OR=2.8, p=0.009) were independent risk factors for this event. Early (within 1-7 days before TA-AVI) preoperative CT and cardiac catheterization did not significantly increase incidence of RRT or AKI. Short-term and long-term survival was explicitly lower in the AKI and in the RRT groups (p<0.001 each).

CONCLUSIONS

GFR improves after TA-AVI. Postoperative AKI and RRT depend on the amount of intra-operative contrast agent. These results strongly support the need for intra-operative tools to reduce contrast-agent exposition during TA-AVI.

Transapical aortic valve implantation following a left pneumonectomy

Transapical transcatheter aortic valve implantation is an emerging technique for high-risk patients with symptomatic aortic valve stenosis, peripheral vascular disease, and severe concomitant comorbidities. However, a previous major surgical intervention involving the left hemithorax and the lung has always been considered a technical surgical challenge or even a potential contraindication for this minimally invasive procedure. With this report, we demonstrate, for the first time, that a previous left pneumonectomy followed by mediastinal radiotherapy does not affect the feasibility of transapical transcatheter aortic valve implantation, and we discuss the preoperative workup and the peculiar intraoperative cardiac imaging and surgical assessment.