Surgery for Valvular Heart Disease
`
`Transapical Minimally Invasive Aortic Valve Implantation
`Multicenter Experience
`
`Thomas Walther, MD, PhD; Paul Simon, MD, PhD; Todd Dewey, MD;
`Gerhard Wimmer-Greinecker, MD, PhD; Volkmar Falk, MD, PhD; Marie T. Kasimir, MD;
`Mirko Doss, MD; Michael A. Borger, MD, PhD; Gerhard Schuler, MD, PhD;
`Dietmar Glogar, MD, PhD; Wolfgang Fehske, MD, PhD; Ernst Wolner, MD, PhD;
`Friedrich W. Mohr, MD, PhD; Michael Mack, MD, PhD
`
`Background—To evaluate initial multicenter results with minimally invasive transapical aortic valve implantation
`(TAP-AVI) for high risk patients with aortic stenosis.
`Methods and Results—TAP-AVI was performed via a small anterolateral minithoracotomy with or without femoro-
`femoral extracorporeal circulation (ECC) on the beating heart. A pericardial xenograft fixed within a stainless steel,
`balloon expandable stent (Edwards SAPIEN THV, Edwards Lifesciences) was used. Fifty-nine consecutive patients
`(81⫾6 years, 44 female) were operated on from 02/06 until 10/06 at 4 centers using fluoroscopic and echocardiographic
`visualization. Average EuroSCORE predicted risk for mortality was 27⫾14%. TAP valve positioning was performed
`successfully in 53 patients, 4 required early conversion to sternotomy. Implantation (23-mm valves in 19 and 26-mm
`valves in 40 patients) was performed on the beating heart during brief periods of rapid ventricular pacing. Thirty-one
`patients were operated on without cardiopulmonary bypass. Neither coronary artery obstruction nor migration of the
`prosthesis was observed, and all valves had good hemodynamic function. Echocardiography revealed minor
`paravalvular leakage in 26 patients (trace in 11, mild in 12, and severe in 3). Eight patients died in-hospital (13.6%)
`without any valve dysfunction. Actuarial survival was 75.7⫾5.9% at a follow-up interval of 110⫾77 days (range 1 to
`255 days).
`Conclusions—TAP-AVI can be performed safely with good early results in high risk patients. Long-term valve
`performance as well as broader based applications of this promising approach will need to be studied. (Circulation.
`2007;116[suppl I]:I-240–I-245.)
`
`Key Words: valves 䡲 aorta 䡲 cardiovascular diseases 䡲 stent fixed xenograft 䡲 transcatheter techniques
`
`Aortic valve replacement is a commonly performed op-
`
`eration with well-defined indications.1 Conventional
`surgical therapy, involving a median sternotomy, along with
`the use of cardiopulmonary bypass (CPB) and cardioplegic
`cardiac arrest has been performed for decades with good
`perioperative and long-term results.2–7 This is true even for
`selected octogenarians.8 In addition to an increasing age at
`operation, contemporary patients present with more comor-
`bidities such as cerebrovascular disease, low ejection frac-
`tion, pulmonary hypertension,
`respiratory insufficiency,
`chronic renal failure, and peripheral arterial occlusive disease
`among others. Preoperative risk assessment
`is routinely
`performed using the EuroSCORE or the STS risk calculator
`for these patients. Novel
`therapeutic strategies,
`including
`beating heart valve implantation via an anterolateral minitho-
`
`racotomy with or without ECC, may be necessary to maintain
`optimal surgical outcomes in these high risk patients. Further
`development of transcatheter techniques may lead to the point
`where truly minimally invasive valve implantation becomes a
`common clinical reality.
`Transapical transcatheter valve implantation techniques
`have been developed recently. Initial experimental evalu-
`ation has been successfully performed by different
`groups.9 –12 Early clinical results, using the device on a
`compassionate basis for high risk patients or for patients
`deemed as inoperable, have been recently published.13 In
`addition, early single-center feasibility experience with the
`device in high risk patients for conventional surgery was
`recently reported.14 The aim of this study is to present the
`initial multicenter results of the first ethically approved
`
`From the University Leipzig, Heartcenter, Departments of Cardiac Surgery (T.W., V.F., M.A.B., F.W.M.) and Cardiology (G.S.), Leipzig, Germany;
`University Hospital AKH, Departments of Cardiothoracic Surgery (P.S., M.T.K., E.W.) and Cardiology (D.G.), Vienna, Austria; Cardiopulmonary
`Research Science and Technology Institute, Department of Cardiac Surgery (T.D., M.M.), Dallas, Tex; Department of Thoracic and Cardiovascular
`Surgery (G.W.-G., M.D.), JW-Goethe University Frankfurt, Germany; and the Department of Cardiology (W.F.), St.-Vinzenz-Hospital, Cologne,
`Germany.
`Correspondence to Prof Dr Thomas Walther, Universita¨t Leipzig, Herzzentrum, Klinik fu¨r Herzchirurgie, Stru¨mpellstrasse 39, 04289 Leipzig,
`Germany. E-mail walt@medizin.uni-leipzig.de
`© 2007 American Heart Association, Inc.
`Circulation is available at http://circ.ahajournals.org
`
`DOI: 10.1161/CIRCULATIONAHA.106.677237
`
`I-240
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`Figure 1. Edwards SAPIEN THV, a xenograft consisting of 3
`bovinepericardial cusps with Thermafix treatment mounted in a
`balloonexpandable stainless steel stent.
`
`transapical minimally invasive aortic
`for
`trial
`clinical
`valve implantation.
`
`Materials and Methods
`The study protocol was jointly developed by an international team of
`cardiac surgeons and cardiologists from the participating centers and
`approved by the local ethics committees (Leipzig, Frankfurt, Vienna)
`or the local study review board (Dallas). Joint inclusion criteria were
`defined as follows: Patient age ⱖ75 years and presence of surgical
`high risk attributable significant comorbidities. Patient risk was
`judged by a EuroSCORE of 9 points or more, which corresponds to
`a predicted perioperative mortality of ⬎11% when applying the
`logistic EuroSCORE risk calculation. Additional technical inclusion
`criteria were an echocardiographically measured aortic annulus
`diameter of ⱕ24 mm as well as symmetrically distributed calcifica-
`tion of the stenotic native aortic valve cusps. All patients signed
`informed consent before inclusion in the study.
`
`Transcatheter Valve Implantation Technique
`A tricuspid pericardial xenograft mounted in a balloon expandable
`low profile stainless steel stent (Edwards SAPIEN THV, formerly
`Cribier-Edwards, Edwards Lifesciences) was used in this clinical
`study. Valve diameters of 23 mm and 26 mm with a stent-height of
`14.5 and 16 mm, respectively, were available for use, depending on
`the size of the patients aortic annulus. The lower inflow portion of
`the valve was covered with polyethylene terephthalate (PET) cloth
`(see Figure 1). Crimping of this sutureless prosthesis onto a balloon
`catheter was performed under sterile conditions by a technician
`immediately before transcatheter implantation.
`Access to the left ventricular apex was gained through a left
`anterolateral minithoracotomy in the fifth intercostal space, with
`horizontal opening of the pericardium and placement of stay sutures
`for exposure. Two teflon-reinforced purse-string sutures (Prolene
`2-0) were then placed at the left ventricular apex lateral to the left
`anterior descending coronary artery. In addition a temporary epicar-
`dial pacing wire was placed on the left ventricle. The left femoral
`vessels were exposed as potential access for CPB. Standard periph-
`eral cannulae for CPB were inserted in cases performed on-pump,
`otherwise only a venous wire was inserted. In addition a femoral
`arterial sheath was placed and an aortic root pigtail catheter inserted
`and guided into the ascending aorta. Under fluoroscopic control the
`apex was punctured and a soft guide wire passed antegrade across the
`
`Figure 2. Schematic illustration of the transapical valve insertion
`technique. Valve implantation through the transapically-inserted
`33 French sheath secured by purse-string sutures is shown.
`
`stenotic aortic valve. A 14 French soft sheath was inserted and a
`superstiff guide wire passed across the aortic arch (Amplatz super-
`stiff, 035“, 260 cm, Boston Scientific). A conventional 20-mm
`valvuloplasty balloon catheter was then positioned at the aortic
`annulus. Balloon valvuloplasty was performed during a brief episode
`of rapid ventricular pacing (150 to 170/min) to temporarily eliminate
`cardiac output from the left ventricle. Then the sheath was ex-
`changed for the 33 French transapical valve delivery system. The
`balloon catheter with the crimped valve was inserted and the system
`carefully deaired. Exact positioning was obtained using fluoroscopic
`guidance such that the aortic annulus bisected the midportion of the
`steel stent. Aortic root angiography (20cc of contrast) was used for
`positional control. During a second episode of rapid ventricular
`pacing, rapid valve deployment was performed using standard
`volumetric inflation of the balloon. Prosthesis function was imme-
`diately evaluated using transesophageal echocardiography as well as
`aortic root angiography. Repeat dilatation of the stent was indicated
`in case of moderate or severe paravalvular incompetence of the
`prosthesis. The transapical sheath was removed and the apex closed
`with the purse-string sutures. The pericardium was partially adapted,
`a chest tube inserted and the incision closed in a routine fashion. The
`patient was transferred to the recovery room or intensive care unit for
`early extubation. The transapical insertion technique is illustrated in
`Figure 2. Device specific medication consisted of aspirin 100 mg
`daily only.
`All procedures were performed in a completely sterile environ-
`ment of a routine operative theater. This allowed for immediate
`conversion to conventional valve surgery and provided for optimal
`patient safety. For fluoroscopic imaging a monoplane angiography
`system (Axiom Sensis, Siemens; hybrid operative theater) or a
`mobile system were used.
`
`Echocardiographic Valve Assessment
`and Follow-Up
`Standard echocardiographic views were used for perioperative
`(transesophageal echocardiography⫽TEE) and postoperative (trans-
`thoracic echocardiography⫽TTE) valve assessment. Left ventricular
`dimensions, left ventricular ejection fraction (EF), and prosthetic
`valve function were evaluated. Mitral valve function before and after
`
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`Circulation
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`September 11, 2007
`
`TABLE 1. Preoperative Patient Characteristics for This
`Multicenter Study in 59 Patients Included From February Until
`October 2006
`
`59
`Patient No.
`81.4⫾5.8
`Patient age, years
`44 (74.6%)
`Female, n
`11.2⫾1.8
`EuroSCORE, points
`26.8⫾13.5
`EuroSCORE predicted risk for mortality, %*
`67⫾14
`Body weight, kg
`3.4⫾0.5
`NYHA class
`10 (16.9%)
`Previous cardiac surgery
`47⫾16
`Ejection fraction, %
`0.5⫾0.15 (range 0.2–0.9)
`AOA, cm2
`NYHA indicates New York Heart Association; AOA, aortic valve orifice area;
`CI, confidence interval.
`*According to logistic EuroSCORE calculations.
`
`implantation as well as concomitant pathologies were routinely
`assessed. Potential aortic valve incompetence was judged as trans-
`valvular or paravalvular and the severity was graded as none, trace,
`mild (1°), moderate (1 to 2°), and severe (2° or higher). All
`echocardiographic examinations were reviewed by an experienced
`and independent local examiner as well as the echocardiographic
`core laboratory (WF).
`
`Statistical Evaluation
`Results are given in a standard fashion throughout the manuscript.
`Continuous variables are expressed as mean⫾SEM or as median
`when appropriate, and categorical variables are expressed as
`proportions.
`The authors had full access to and take full responsibility for the
`integrity of the data. All authors have read and agree to the
`manuscript as written.
`
`Results
`A total of 59 patients with significant aortic valve stenosis at
`4 centers were included in this clinical study from February
`2006 until October 2006. Patients were enrolled at Leipzig
`(30), Vienna (24), Frankfurt (3), and Dallas (2), respectively.
`Patient age at implantation was 81.4⫾5.8 years and 74.6%
`were female. A total of 3 patients younger than 75 years were
`included because of their severe comorbidities, after addi-
`tional approval by the ethics committees. Preoperative risk
`assessment by EuroSCORE revealed a mean of 11.2⫾1.8
`points, corresponding to a predicted risk for mortality of
`26.8⫾13.5% (logistic EuroSCORE). Previous cardiac sur-
`gery had been performed in 10 patients (16.9%), 8 of which
`had received coronary artery bypass grafting with patent
`grafts and 1 patient each post aortic valvuloplasty and mitral
`valve repair. A summary of preoperative patient characteris-
`tics is given in Table 1.
`To provide a more detailed overview of the patients’ risk
`profile, significant comorbidities and factors not necessarily
`reflected by the EuroSCORE are given in Table 2. This
`indicates that, in addition to the high EuroSCORE predicted
`risk, the patients included into this study suffered severe
`comorbidities. All patients with concomitant mitral valve
`regurgitation (n⫽24) had mild or moderate insufficiency, not
`requiring additional mitral valve surgery in the presence of
`tight aortic stenosis.
`
`TABLE 2. Additional Patient Risk Factors not Necessarily
`Reflected by the EuroSCORE Risk Assessment (total nⴝ59)
`
`Coronary artery disease*
`Recent myocardiac infarction
`Presence of mitral incompetence#
`Degree of mitral incompetence
`Recent cardiac decompensation
`Arrhythmia
`Pulmonary hypertension
`Previous stroke
`Respiratory dysfunction / COPD
`Renal failure
`Renal failure on dialysis
`Hypertension
`Diabetes mellitus
`Leukemia
`
`n
`
`22
`7
`24
`1.2⫾0.4
`18
`16
`19
`9
`13
`20
`3
`44
`16
`3
`
`%
`
`37.3
`11.9
`40.7
`
`30.5
`27.1
`32.2
`15.3
`22.0
`33.9
`5.1
`74.6
`27.1
`5.1
`
`COPD indicates chronic obstructive pulmonary disease.
`*Diffuse coronary artery disease without any indication for surgical treatment
`or status post PTCA; #no indication for concomitant surgical valve repair
`
`Perioperative outcome is summarized in Table 3. The
`difference of 2.5 mm between echocardiographically mea-
`sured aortic annulus diameter (TEE) and implanted valve size
`indicates that the oversizing technique was applied in all
`patients. Perioperative conversion to sternotomy was required
`in 4 patients, all because of incorrect positioning of the valve.
`The valve was inadvertently positioned too high and too low
`in 2 patients each. Two of these malpositions occurred early
`in the series, 1 when fluoroscopic imaging was unavailable
`(only TEE was used) because of technical problems, and 1 in
`the presence of severe focal calcification of 1 of the native
`aortic valve cusps. Two of the patients requiring conversion
`died in-hospital.
`
`TABLE 3. Perioperative Results
`
`Aortic annulus diameter as measured by TEE, mm
`
`Implanted valve size, mm
`23 mm prosthesis, n
`26 mm prosthesis, n
`Good valve positioning, n
`Perioperative conversion to conventional sternotomy
`Use of ECC, n
`Cannulation for ECC, n
`Implantations performed off-pump, n
`Contrast given, ml
`Fluoroscopy, min
`Repeat dilatation of the valve
`Additional apical sutures
`(with ECC)
`OR time, min
`
`22.5⫾1.6
`(range 19–25)
`25⫾1.4
`19
`40 (67.8%)
`55 (93.2%)
`4 (6.8%)
`28 (47.5%)
`41 (69.5%)
`31 (52.5%)
`80.5⫾45
`8.4⫾5.2
`12
`12
`(6)
`148⫾92
`TEE indicates transesophageal echocardiography; ECC, extracorporeal cir-
`culation.
`
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`Transapical Minimally Invasive AVI
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`TABLE 4. Postoperative Outcome and Follow-Up, Effective
`October 31, 2006
`
`TABLE 5.
`
`Echocardiographic Results at Discharge
`
`95% CI
`
`Intubation time, median, hrs
`Same day extubation, n
`ICU stay, median, hrs
`Postoperative complications
`None
`Stroke
`Pleural effusion
`Supraventricular arrhythmia
`Transient hemofiltration
`Tracheostomy
`CPR (successful)
`Pericardial effusion
`Rethoracotomy
`(chestwall / diffuse bleeding)
`30-day mortality
`In-hospital mortality
`Follow-up mortality
`Overall mortality
`Follow-up interval, days
`
`6
`37 (62.7%)
`20
`
`11
`2
`18
`18
`8
`8
`4 (3)
`3
`8
`(7)
`8 (13.6%)
`8 (13.6%)
`5 (9.8%)
`13 (22%)
`110⫾77
`
`ICU indicates intensive care unit.
`
`Implantations were performed on-pump in the beginning of
`the study. With increasing experience, however, femoral
`cannulation only was performed without using CPB. Recently
`18 patients received off-pump valve implantation with only a
`femoral venous wire in place. Repeat valve dilatation using
`rapid ventricular pacing was performed because of uneven
`stent expansion leading to moderate or severe paravalvular
`leak in 12 patients. Closure of the left ventricular apex was
`uncomplicated when using sufficiently deep bites in the
`presence of firm apical tissue. Additional sutures were re-
`quired in 12 patients, 6 of whom had to be performed during
`ventricular unloading using CPB. The total procedure time
`decreased with increasing experience throughout the study.
`Currently a straight forward transapical valve implantation
`can be routinely performed in less than 80 minutes.
`Results on postoperative outcomes are given in Table 4.
`Despite their high-risk profile, a majority of patients were
`extubated early and had a short intensive care unit stay. The
`postoperative morbidity is acceptable in view of the high
`perioperative risk profile and in comparison to the results
`after conventional surgical valve replacement. The transapi-
`cal approach proved to be safe with only 1 return to the
`operating room for postoperative apical bleeding. The inci-
`dence of stroke (n⫽2) was low in this series.
`In-hospital and 30-day mortality (n ⫽8) were both 13.6%.
`Good valve function with patent coronary arteries was proven
`in all patients that died at autopsy. Therefore none of the
`deaths was valve related. Despite observing a relatively high
`mortality the overall outcome compares favorably to the risk
`profile (EuroSCORE 26.8%) of the patients. Mortality can be
`clearly attributed to the overall clinical condition and health
`status of the patients and is not directly related to the
`procedure of TAP-AVI. As of the end of October 2006,
`
`40
`2⫾0.6
`18⫾11
`9⫾6
`
`1.81–2.19
`14.9–21.1
`7.3–10.7
`
`n
`Vmax, m/s
`Pmax, mm Hg
`Pmean, mm Hg
`Grade of aortic incompetence
`none
`14
`trace
`11
`mild (1°)
`12
`moderate (1–2°)
`2
`severe (2° or higher)
`1
`Paravalvular incompetence
`17/26
`Vmax indicates maximum transvalvular blood flow velocity; Pmax, maximum
`transvalvular pressure gradient; Pmean, mean transvalvular pressure gradient;
`CI, confidence interval.
`
`follow-up was 110⫾77 days (1 to 255 days). Five additional
`patients died during follow-up, resulting in an overall mor-
`tality of 22%. Causes of death during follow-up were respi-
`ratory and renal insufficiency in 2, heart failure in 1, sepsis in
`1, and unclear in 1 patient.
`Echocardiographic results are given in Table 5. Good valve
`function with low blood flow velocities and low pressure
`gradients were observed in all patients. Some degree of aortic
`valve incompetence was diagnosed in 26 of 40 patients that
`were available for routine echocardiographic assessment at
`discharge. Aortic valve incompetence was trace, mild, or
`moderate in most of the patients, and none of them suffered
`any symptoms. In addition there were no signs of hemolysis
`in any of the patients. During follow-up, no increase in aortic
`valve incompetence occurred. At current follow up, 46 (78%)
`of the patients are alive. Actuarial survival for the whole
`patient group is 75.7⫾5.9% and is given in Figure 3.
`
`Discussion
`Minimally invasive transapical aortic valve implantation
`(TAP-AVI) is a novel surgical procedure developed in part to
`deal with an increasing preoperative risk profile of patients
`with aortic valve disease. The goal of this procedure is to
`
`Figure 3. Actuarial survival (Kaplan-Meier) at 110⫾77 days
`[range 1 to 255] follow-up.
`
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`Circulation
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`
`decrease the invasiveness of the current gold standard, con-
`ventional aortic valve replacement surgery, while maintaining
`excellent long-term results by taking advantage of recent
`technical developments in the field of transcatheter valve
`implantation. Primarily, good functional and hemodynamic
`results should be achieved when performing sutureless valve
`implantation. Careful assessment of patient related factors
`including thoughtful preoperative risk assessment is required
`for further evaluation of this new approach. Early feasibility
`trials of TAP-AVI are under way.13,14 A pivotal study is being
`designed at present and eventually randomized studies will
`follow.
`The current article summarizes the first multicenter expe-
`rience of TAP-AVI in a relatively large number of patients
`(n⫽59) being treated under an ethically approved protocol.
`The present results are good, especially when considering the
`overall risk profile of the patients included in this study. It is
`also important to note that a learning curve is associated with
`this new technique and that the participating centers had
`differing levels of experience with transcatheter techniques
`before beginning the study. This successful multicenter ex-
`perience is an important step for further broader-based
`application of the promising technique of TAP-AVI. We
`believe that further expansion of this investigational proce-
`dure to more institutions is warranted and that randomized
`trials are in the foreseeable future.
`Initial results in 7 patients deemed as nonoperable that
`received transapical aortic valve implantation on a compas-
`sionate use protocol have been recently published.13 We
`included similarly high risk patients in the current series, with
`the difference being that we often perform conventional
`aortic valve surgery on such patients because we seldom
`deem aortic stenosis patients as inoperable. Generally speak-
`ing, patient selection and inclusion criteria are a critical factor
`when performing studies on new devices in high risk popu-
`lations. Sufficient patient survival should be achieved to be
`able to evaluate longer term outcomes. This may be in
`contradiction to the high risk profile of the patients and will
`definitively exclude multimorbid candidates. For better defi-
`nition of inclusion criteria we used a higher EuroSCORE and
`a patient age of ⱖ75 years. Older age alone should not be the
`sole indicator of high surgical risk, and after the present
`experience we think that our inclusion criteria were appro-
`priate. Based on our criteria, patients with a predicted risk of
`approximately 27% were included. We observed a mortality
`of approximately half of predicted (13.6%) and therefore feel
`our results are satisfactory. Patients with poor ejection frac-
`tion and severe respiratory insufficienty seemed to benefit the
`most from the minimally invasive approach. However, fur-
`ther long-term evaluation should be performed before includ-
`ing younger patients that are probably better served with
`conventional valve replacement. For future studies a Euro-
`SCORE predicted risk for mortality of ⱖ20% and a STS risk
`score ⱖ10% may serve as uniform inclusion criteria together
`with a primary end point of one year survival.
`The incidence of stroke was low in the current series. This
`low risk with TAP-AVI might be explained by the fact that all
`implants were performed using an antegrade technique,
`without excessive wire or catheter manipulation in the as-
`
`cending aorta and the aortic arch. When manipulating a
`superstiff wire around a potentially calcified aortic arch—
`which is required for the retrograde transfemoral approach-
`es—particulate embolization with subsequent stroke can oc-
`cur. In addition, direct antegrade passage through the native
`stenotic aortic valve proved to be relatively easy in this series.
`Complete unloading of the heart during native aortic valve
`dilatation and during valve implantation is important to avoid
`any detachment of calcium from the annulus. This can easily
`be achieved using rapid ventricular pacing as performed in
`this series.
`It is informative to compare this multicenter experience to
`other published results. Cribier has pioneered the field of
`transcatheter valve implantation. Using only a 23-mm steel
`stent prosthesis, and therefore without consequently using the
`oversizing technique, he first reported acceptable results in
`patients in 2002.15–17 Valves were implanted through a
`transfemoral arterial retrograde or a transfemoral venous
`antegrade transseptal approach. CoreValve, a porcine pericar-
`dial valve mounted within a Nitinol stent of 5 cm length, is
`another device currently under clinical investigation in the
`aortic position. It is designed in a way that the stent is
`positioned across the aortic sinuses without obstructing cor-
`onary flow. Lifelong antiplatelet therapy using aspirin and
`clopidogrel is required. This may be a disadvantage espe-
`cially in the elderly high risk patients. Initial results after
`transfemoral insertion of the 25 French and the 21 French
`CoreValve were recently published.18 The overall in-hospital
`mortality of 20% is quite high when considering the Euro-
`SCORE predicted risk was only 11% in this series.
`The transapical approach used in this series is a straight-
`forward procedure that allows for safe and reproducible
`transcatheter valve implantation. As proven by this series, the
`procedure is standardized, reproducible, and relatively sim-
`ple. This will lead to longer-term successful applications. The
`transapical access can be safely secured when using standard
`purse-string sutures. For valve implantation fluoroscopic
`visualization is most useful, in parallel with continuous TEE
`monitoring. Transfemoral arterial valve implantation may be
`performed with similar reliability. However, retrograde pas-
`sage of the stenotic aortic valve as well as the longer distance
`for precise manipulation of the valve, sometimes being more
`than 100 cm from the femoral access to the aortic annulus,
`have to be considered. The transapical approach provides a
`direct and easy access with excellent manipulation of the
`device. With the transapical technique no limitation in sheath
`diameter exists, allowing for the implantation of large and
`eventually cuffed prostheses to achieve a functionally optimal
`result for the patients.
`One of the most important aspects of the current multi-
`center trial is the transnational team approach used by the
`cardiac surgeons, as well as the excellent cooperation with
`local cardiologists and anesthesiologists. Input from different
`members of the team led to a continuous refinement of the
`procedure toward a more and more minimally invasive
`approach. Catheter-based skills will undoubtedly become an
`increasingly important for cardiac surgeons interested in
`pursuing this technique for aortic valve replacement.19 Addi-
`tionally, increased cooperation with interventional cardiolo-
`
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`gists interested in structural valvular heart disease will be
`useful to promote this unique therapy. We may foresee the
`development of specialized “valve teams” made up of cardiac
`surgeons, cardiologists, anesthetists, and others, all dedicated
`to the optimal and potential minimally invasive treatment of
`the patients.
`Future refinements of the sutureless devices should focus
`on further minimizing the risk for paravalvular leakage. In
`addition, smaller devices may be advantageous. Most impor-
`tantly, a retrieval mechanism allowing for safe removal of a
`malpositioned prosthesis and redeployment of the device
`would be highly advantageous. Training of physicians for
`these procedures, possibly involving a simulator, may have to
`be implemented. Correct valve implantation may be further
`supported by image guided mechatronic assistance. This
`would include (1) preoperative planning including segmenta-
`tion of the aortic root from computer tomography (CT) data,
`and virtual placement of the appropriate valve within the
`reconstructed root, (2) registration of the CT data with intra-
`operative imaging (ie, TEE) using suitable landmarks such as
`the commissures, and (3) automatic positioning and place-
`ment of the valve using a mechatronic device that would be
`guided by a predictive algorithm that compensates for the
`dynamics of aortic root motion.
`In summary TAP-AVI is a promising technique with
`proven feasibility in selected high risk patients. The early
`multicenter experience is encouraging, proving a reproduc-
`ible technique with good perioperative results and acceptable
`hemodynamic function of the implanted prostheses. Coronary
`perfusion is well preserved when using modern imaging
`techniques during valve positioning and implantation. The
`risk of paravalvular leakage will always remain an important
`issue for the evaluation of sutureless devices, but may
`partially be solved by the oversizing technique. Future
`randomized and longer-term follow-up evaluations are re-
`quired. Conventional aortic valve replacement surgery re-
`mains the gold standard at present.
`
`Acknowledgments
`We are very grateful to Mark Dehdashtian, Teodoro Jimenez, and Sal
`Marquez (all Edwards Lifesciences Irvine, Calif) for their continuous
`technical support when performing this study.
`
`Disclosures
`Michael Mack, Todd Dewey, Gerhard Wimmer-Greinecker, and
`Friedrich W. Mohr are consultants to Edwards Lifesciences, Inc.
`
`References
`1. Bonow RO, Carabello BA, Chatterjee K. ACC/AHA 2006 Guidelines for
`the management of patients with valvular heart disease: Executive
`summary. Circulation. 2006;114:450 –527.
`2. Borger MA, Ivanov J, Armstrong S, Christie-Hrybinsky D, Feindel CM,
`David TE. Twenty-year results of the Hancock II bioprosthesis. J Heart
`Valve Dis. 2006;15:49 –55.
`
`3. Myken PS. Seventeen-year experience with the St. Jude Medical Biocor
`porcine bioprosthesis. J Heart Valve Dis. 2005;14:486 – 492.
`4. Banbury MK, Cosgrove DM 3rd, Thomas JD, Blackstone EH,
`Rajeswaran J, Okies JE, Frater RM. Hemodynamic stability during 17
`years of the Carpentier-Edwards aortic pericardial bioprosthesis. Ann
`Thorac Surg. 2002;73:1460 –1465.
`5. Blackstone EH, Cosgrove DM, Jamieson WR, Birkmeyer NJ, Lemmer JH
`Jr., Miller DC, Butchart EG, Rizzoli G, Yacoub M, Chai A: Prosthesis
`size and long-term survival after aortic valve replacement. J Thorac
`Cardiovasc Surg. 2003;126:783–796.
`6. Grocott-Mason RM, Lund O, Elwidaa H, Mazhar R, Chandrasakeran V,
`Mitchell AG, Ilsley C, Khaghani A, Rees A, Yacoub M: Long-term
`results after aortic valve replacement in patients with congestive heart
`failure. Homografts vs prosthetic valves. Eur Heart J. 2000;21:
`1698 –1707.
`7. Walther T, Rastan A, Falk V, Lehmann S, Garbade J, Funkat AK, Mohr
`FW, Gummert JF. Patient prosthesis mismatch affects short- and
`long-term outcome after aortic valve replacement. Eur J Cardiothorac
`Surg. 2006;30:15–19.
`8. Chukwuemeka A, Borger MA, Ivanov J, Armstrong S, Feindel CM,
`David TE. Valve surgery in octogenarians: a safe option with good
`medium-term results. J Heart Valve Dis. 2006;15:191–196.
`9. Huber SH, Tozzi P, Corno AF, Marty B, Ruchat P, Gersbach P, Nas-
`ratulla M, von Segesser LK. Do valved stents compromise coronary flow?
`Eur J Cardio Thorac Surg. 2004;25:754.
`10. Huber CH, Nasratulla M, Augustburger M, von Segesser LK. Ultrasound
`navigation through the heart for off-pump aortic valved stent implan-
`tation: new tools for new goals. J Endovasc Ther. 2004;11:503–510.
`11. Dewey T, Walther T, Doss M, Brown D, Ryan WH, Svensson L,
`Mihaljevic T, Hambrecht R, Schuler G, Wimmer-Greinecker G, Mohr
`FW, Mack M. Transapical aortic valve implantation: An animal feasi-
`bility study. Ann Thorac Surg. 2006;82:110 –116.
`12. Walther T, Dewey T, Wimmer-Greinecker G, Doss M, Hambrecht R,
`Schuler G, Mohr FW, Mack M. Trans-apical approach for sutureless
`stent-fixed aortic valve implantation: Experimental results. Eur J Cardio-
`thorac Surg. 2006;29:703–708.
`13. Lichtenstein SV, Cheung A, Ye J, Thompson CR, Carere RG, Pasupati S,
`Webb JG. Transapical transcatheter aortic valve implantation in humans.
`Initial clinical experience. Circulation. 2006;114:591–596.
`14. Walther T, Falk V, Borger MA, Dewey T, Wimmer-Greinecker G,
`Schuler G, Mack M, Mohr FW. Minimally invasive transapical beating
`heart aortic valve implantation – proof of concept. Eur J Cardiothorac
`Surg. 2007;31:9 –15.
`15. Cribier A, Eltchaninoff H, Bash A, Borenstein N, Tron C, Bauer F,
`Derumeaux G, Anselme F, Laborde F, Leon MB. Percutaneous transcath-
`eter implantation of an aortic valve prosthesis for calcific aortic stenosis:
`first human case description. Circulation. 2002;106:3006 –3008.
`16. Cribier A, Eltchaninoff H, Tron C, Bauer F, Agatiello C, Sebagh L, Bash
`A, Nusimovici D, Litzler PY, Bessou JP, Leon MB. Early experience with
`percutaneous transcatheter implantation of hea