Valved stents for transapical pulmonary valve replacement.

OBJECTIVES: Pulmonary valve insufficiency remains a leading cause for reoperations in congenital cardiac surgery. The current percutaneous approach is limited by the size of the access vessel and variable right ventricular outflow tract morphology. This study assesses the feasibility of transapical pulmonary valve replacement based on a new valved stent construction concept. METHODS: A new valved stent design was implanted off-pump under continuous intracardiac echocardiographic and fluoroscopic guidance into the native right ventricular outflow tract in 8 pigs (48.5 +/- 6.0 kg) through the right ventricular apex, and device function was studied by using invasive and noninvasive measures. RESULTS: Procedural success was 100% at the first attempt. Procedural time was 75 +/- 15 minutes. All devices were delivered at the target site with good acute valve function. No valved stents dislodged. No animal had significant regurgitation or paravalvular leaking on intracardiac echocardiographic analysis. All animals had a competent tricuspid valve and no signs of right ventricular dysfunction. The planimetric valve orifice was 2.85 +/- 0.32 cm(2). No damage to the pulmonary artery or structural defect of the valved stents was found at necropsy. CONCLUSIONS: This study confirms the feasibility of direct access valve replacement through the transapical procedure for replacement of the pulmonary valve, as well as validity of the new valved stent design concept. The transapical procedure is targeting a broader patient pool, including the very young and the adult patient. The device design might not be restricted to failing conduits only and could allow for implantation in a larger patient population, including those with native right ventricular outflow tract configurations.

Transapical aortic 'valve-in-valve' procedure for degenerated stented bioprosthesis.

Standard surgical aortic valve replacement with a biological prosthesis remains the treatment of choice for low- and mid-risk elderly patients (traditionally >65 years of age) suffering from severe symptomatic aortic valve stenosis or insufficiency, and for young patients with formal contraindications to long-lasting anticoagulation. Unfortunately, despite the fact that several technical improvements have noticeably improved the resistance of pericardial and bovine bioprostheses to leaflet calcifications and ruptures, the risk of early valve failure with rapid degeneration still exists, especially for patients under haemodialysis and for patients <60 years of age at the time of surgery. Until now, redo open heart surgery under cardiopulmonary bypass and on cardioplegic arrest was the only available therapeutic option in case of bioprosthesis degeneration, but it carried a higher surgical risk when elderly patients with severe concomitant comorbidities were concerned. Since a few years, the advent of new transcatheter aortic valve procedures has opened new horizons in cardiac surgery and, in particular, the possibility of implanting stented valves within the degenerated stented bioprosthesis, the so-called 'valve-in-valve' (VinV) concept, has become a clinical practice in experienced cardiac centres. The VinV procedure represents a minimally invasive approach dedicated to high-risk redo patients, and published preliminary reports have shown a success rate of 100% with absence of significant valvular leaks, acceptable transvalvular gradients and low complication rate. However, this procedure is not riskless and the most important concerns are about the size mismatch and the right positioning within the degenerated bioprosthesis. In this article, we review the limited available literature about VinV procedures, underline important technical details for the positioning and provide guidelines to prevent valve-prosthesis mismatch comparing the three sizes of the only commercially available transapical device, the Edwards Sapien, with the inner diameter of three of the most commonly used stented bioprostheses.

Transcatheter aortic valve implantation (TAVI): state of the art techniques and future perspectives.

Transcatheter aortic valve therapies are the newest established techniques for the treatment of high risk patients affected by severe symptomatic aortic valve stenosis. The transapical approach requires a left anterolateral mini-thoracotomy, whereas the transfemoral method requires an adequate peripheral vascular access and can be performed fully percutaneously. Alternatively, the trans-subclavian access has been recently proposed as a third promising approach. Depending on the technique, the fine stent-valve positioning can be performed with or without contrast injections. The transapical echo-guided stent-valve implantation without angiography (the Lausanne technique) relies entirely on transoesophageal echocardiogramme imaging for the fine stent-valve positioning and it has been proved that this technique prevents the onset of postoperative contrast-related acute kidney failure. Recent published reports have shown good hospital outcomes and short-term results after transcatheter aortic valve implantation, but there are no proven advantages in using the transfemoral or the transapical technique. In particular, the transapical series have a higher mean logistic Euroscore of 27-35%, a procedural success rate above 95% and a mean 30-day mortality between 7.5 and 17.5%, whereas the transfemoral results show a lower logistic Euroscore of 23-25.5%, a procedural success rate above 90% and a 30-day mortality of 7-10.8%. Nevertheless, further clinical trials and long-term results are mandatory to confirm this positive trend. Future perspectives in transcatheter aortic valve therapies would be the development of intravascular devices for the ablation of the diseased valve leaflets and the launch of new stent-valves with improved haemodynamic, different sizes and smaller delivery systems.

How to Preserve Renal Function in Transcatheter Aortic Valve Therapies

Background: Transcatheter aortic valve implantations (TAVI) are indicated in high risk patients requiring aortic valve replacement (AVR). However, CT-scans, coronary angiograms and intraoperative aortographies can induce contrast-related nephro-toxicity with a concrete risk of acute postoperative renal failure, especially in severely diseased patients. To prevent this complication, we routinely perform transapical (TA) TAVI guided by transesophageal echocardiogram and fluoroscopy without angiography. Material and Methods: From November 2008 to December 2009, 31 high-risk patients suffering from severe symptomatic aortic stenosis underwent TA-TAVI in our institution. The preoperative imaging assessment (cardiac CT-scan and coronary angiogram) was performed no less than 10 days before the TA-TAVI in all patients (to recover the renal function) with a low-dose protocol for injected contrast medium (equivalent to the patient's weight for the CT-scan). During the TA-TAVI, the stent-valve positioning was performed without any contrast injection. Results: 32 consecutive stent-valve were successfully positioned in 31 patients (mean age 80.76 8 8.3 years; mean EuroSCORE: 32.2 8 12.9%) through a transapical access (1 patient required 2 valves for valve embolisation). The mean preoperative creatinine and urea blood levels were 102.6 8 67.7 _ g/dl (range 53-339 _ g/dl) and 8.45 8 4.9 mmol/l, respectively. A chronic renal insufficiency affected 12 patients (38.7%) with 1 patient in pre-dialysis. Postoperatively, no patient developed acute myocardial infarction, atrio-ventricular block or acute renal insufficiency (mean creatinine level: 89.7 8 64.55 _ g/dl; urea level: 7.11 8 3.47 mmol/l) and the 30-days mortality was 9.67% (3 patients). Conclusion: Specific preoperative and intraoperative protocols that require lowdoses or absence of contrast medium are useful to preserve the renal function in high risk patients operated for TAVI.

Urgent reoperative transapical valve-in-valve shortly after a transapical aortic valve implantation.

Urgent reoperative transapical aortic valve-in-valve has never been proposed as a treatment option in case of a failed transcatheter aortic valve implantation (TAVI) or in case of worsening of an existing paravalvular leak, if this complication occurs right after, or a few days after, the primary transapical aortic valve implantation. Experienced surgeons should argue that after a transapical TAVI, the apex is damaged and fragile, with a high risk of irreparable ventricular tears and life-threatening bleeding if a second transapical procedure is scheduled during the acute phase. Nevertheless, if the patient is inoperable and the vascular status, including the ascending aorta, limits alternative accesses, the urgent reoperative transapical valve-in-valve becomes an alternative. We illustrate, for the first time ever, our experience with an 81-year old female patient who underwent a transapical (TA) TAVI with a Sapien? XT 23 mm. The day after the procedure, the patient haemodynamically worsened in combination with a worsening of a known (grade 1-2) paravalvular leak. Thus, on postoperative day two, an urgent transapical valve-in-valve was performed, and a second Sapien? XT 23 mm was placed, with an excellent haemodynamic result and absence of leak. The redo apical access did not appear very complicated and the postoperative recovery was uneventful.

Transcatheter aortic valve implantation in a lung transplant recipient.

Transcatheter aortic valve implantation is a feasible therapeutic option for selected patients with severe aortic stenosis and high or prohibitive risk for standard surgery. Lung transplant recipients are often considered high-risk patients for heart surgery because of their specific transplant-associated characteristics and comorbidities. We report a case of successful transfemoral transcatheter aortic valve replacement in a lung transplant recipient with a symptomatic severe aortic stenosis, severe left ventricular dysfunction, and end-stage renal failure 9 years after bilateral lung transplantation.

Successful Transapical Aortic Valve Implantation in a Congenital Bicuspid Aortic Valve.

Transcatheter stent-valve implantation in stenosed congenital bicuspid aortic valves is under debate. Heavily calcified elliptic bicuspid valves represent a contraindication to catheter-based valve therapies because of a risk of stent-valve displacement, distortion, or malfunctioning after the implantation. In this case report we illustrate our experience with a patient suffering from stenosed congenital bicuspid aortic valve who successfully underwent a transapical 26-mm Edwards Sapien stent-valve (Edwards Lifesciences Inc, Irvine, CA) implantation. Postoperative distortion, malfunctioning, and paravalvular leaks were not detected.

Transcatheter aortic valve implantation in failed bioprosthetic surgical valves.

IMPORTANCE: Owing to a considerable shift toward bioprosthesis implantation rather than mechanical valves, it is expected that patients will increasingly present with degenerated bioprostheses in the next few years. Transcatheter aortic valve-in-valve implantation is a less invasive approach for patients with structural valve deterioration; however, a comprehensive evaluation of survival after the procedure has not yet been performed. OBJECTIVE: To determine the survival of patients after transcatheter valve-in-valve implantation inside failed surgical bioprosthetic valves. DESIGN, SETTING, AND PARTICIPANTS: Correlates for survival were evaluated using a multinational valve-in-valve registry that included 459 patients with degenerated bioprosthetic valves undergoing valve-in-valve implantation between 2007 and May 2013 in 55 centers (mean age, 77.6 [SD, 9.8] years; 56% men; median Society of Thoracic Surgeons mortality prediction score, 9.8% [interquartile range, 7.7%-16%]). Surgical valves were classified as small (≤21 mm; 29.7%), intermediate (>21 and <25 mm; 39.3%), and large (≥25 mm; 31%). Implanted devices included both balloon- and self-expandable valves. MAIN OUTCOMES AND MEASURES: Survival, stroke, and New York Heart Association functional class. RESULTS: Modes of bioprosthesis failure were stenosis (n = 181 [39.4%]), regurgitation (n = 139 [30.3%]), and combined (n = 139 [30.3%]). The stenosis group had a higher percentage of small valves (37% vs 20.9% and 26.6% in the regurgitation and combined groups, respectively; P = .005). Within 1 month following valve-in-valve implantation, 35 (7.6%) patients died, 8 (1.7%) had major stroke, and 313 (92.6%) of surviving patients had good functional status (New York Heart Association class I/II). The overall 1-year Kaplan-Meier survival rate was 83.2% (95% CI, 80.8%-84.7%; 62 death events; 228 survivors). Patients in the stenosis group had worse 1-year survival (76.6%; 95% CI, 68.9%-83.1%; 34 deaths; 86 survivors) in comparison with the regurgitation group (91.2%; 95% CI, 85.7%-96.7%; 10 deaths; 76 survivors) and the combined group (83.9%; 95% CI, 76.8%-91%; 18 deaths; 66 survivors) (P = .01). Similarly, patients with small valves had worse 1-year survival (74.8% [95% CI, 66.2%-83.4%]; 27 deaths; 57 survivors) vs with intermediate-sized valves (81.8%; 95% CI, 75.3%-88.3%; 26 deaths; 92 survivors) and with large valves (93.3%; 95% CI, 85.7%-96.7%; 7 deaths; 73 survivors) (P = .001). Factors associated with mortality within 1 year included having small surgical bioprosthesis (≤21 mm; hazard ratio, 2.04; 95% CI, 1.14-3.67; P = .02) and baseline stenosis (vs regurgitation; hazard ratio, 3.07; 95% CI, 1.33-7.08; P = .008). CONCLUSIONS AND RELEVANCE: In this registry of patients who underwent transcatheter valve-in-valve implantation for degenerated bioprosthetic aortic valves, overall 1-year survival was 83.2%. Survival was lower among patients with small bioprostheses and those with predominant surgical valve stenosis.

Transcatheter aortic "valve-in-valve" for degenerated bioprostheses: Choosing the right TAVI valve.

Bioprosthetic aortic valve replacement is the treatment of choice for patients over 65 years of age suffering from aortic valve disease, and for younger patients with contraindications to long-lasting anticoagulation. Despite several technical improvements to reduce the risk of structural valve degeneration (SVD), the risk of SVD still exists, in particular for hemodialysis patients and patients under 60 years of age at surgery. Redo open heart surgery is the treatment of choice in case of valve degeneration, but caries a higher surgical risk when elderly patients with comorbidities are concerned. In the last 5 years, transcatheter aortic "valve-in-valve" procedures represent a valid alternative to standard redo surgery in selected patients. Valve-in-valve procedures represent a less invasive approach in high-risk patients and the published results are very encouraging. Technical success rates of 100% have been reported, as have the absence of paravalvular leaks, acceptable trans-valvular gradients (depending on the size of the original bioprosthesis), and low complication rates. The current article focuses on choosing the correct transcutaneous valve to match the patient's existing bioprosthesis for valve-in-valve procedures.

Transapical aortic valve replacement in extreme-risk patients: outcome, risk factors and mid-term results.

OBJECTIVES: Transcatheter aortic valve replacement (TAVR) provides good results in selected high-risk patients. However, it is unclear whether this procedure carries advantages in extreme-risk profile patients with logistic EuroSCORE above 35%. METHODS: From January 2009 to July 2011, of a total number of 92 transcatheter aortic valve procedures performed, 40 'extreme-risk' patients underwent transapical TAVR (TA-TAVR) (EuroSCORE above 35%). Variables were analysed as risk factors for hospital and mid-term mortality, and a 2-year follow-up (FU) was obtained. RESULTS: The mean age was: 81 ± 10 years. Twelve patients (30%) had chronic pulmonary disease, 32 (80%) severe peripheral vascular disease, 14 (35%) previous cardiac surgery, 19 (48%) chronic renal failure (2 in dialysis), 7 (17%) previous stroke (1 with disabilities), 3 (7%) a porcelain aorta and 12 (30%) were urgent cases. Mean left ventricle ejection fraction (LVEF) was 49 ± 13%, and mean logistic EuroSCORE was 48 ± 11%. Forty stent-valves were successfully implanted with six Grade-1 and one Grade-2 paravalvular leakages (success rate: 100%). Hospital mortality was 20% (8 patients). Causes of death following the valve academic research consortium (VARC) definitions were: life-threatening haemorrhage (1), myocardial infarction (1), sudden death (1), multiorgan failure (2), stroke (1) and severe respiratory dysfunction (2). Major complications (VARC definitions) were: myocardial infarction for left coronary ostium occlusion (1), life-threatening bleeding (2), stroke (2) and acute kidney injury with dialysis (2). Predictors for hospital mortality were: conversion to sternotomy, life-threatening haemorrhage, postoperative dialysis and long intensive care unit (ICU) stay. Variables associated with hospital mortality were: conversion to sternotomy (P = 0.03), life-threatening bleeding (P = 0.02), acute kidney injury with dialysis (P = 0.03) and prolonged ICU stay (P = 0.02). Mean FU time was 24 months: actuarial survival estimates for all-cause mortality at 6 months, 1 year, 18 months and 2 years were 68, 57, 54 and 54%, respectively. Patients still alive at FU were in good clinical condition, New York Heart Association (NYHA) class 1-2 and were never rehospitalized for cardiac decompensation. CONCLUSIONS: TA-TAVR in extreme-risk patients carries a moderate risk of hospital mortality. Severe comorbidities and presence of residual paravalvular leakages affect the mid-term survival, whereas surviving patients have an acceptable quality of life without rehospitalizations for cardiac decompensation.

Transaortic transcatheter aortic valve replacement with the Sapien? valve and the first generations of Ascendra?.

Traditionally, the transcatheter aortic valve replacement is performed through a transapical, a transfemoral or a trans-subclavian approach. Recently, the transaortic approach for transcatheter aortic valve replacement through the distal part of the ascending aorta was successfully implemented in order to avoid peripheral vascular access-related complications and apical life-threatening haemorrhage. The Sapien? stent valve has great transaortic potential because it can be loaded 'upside down' in different generations of delivery systems. However, because of their health regulatory systems and despite the launch, in 2012, of the latest generation of the Ascendra? delivery system, the Ascendra+?, specifically designed for transapical and transaortic valve placements, several countries are still using the first generations of Ascendra? (Ascendra? 1 and 2). This device was specifically designed for transapical procedures, and retrograde stent-valve positioning through the stenotic aortic valve may be very challenging and risk the integrity of the aorta. We describe the manoeuvre required in order to pass the stenotic aortic valve safely in a retrograde direction using the Sapien? stent valve and the first generations of Ascendra?.

Localized amyloid light-chain amyloidosis and extramedullary plasmacytoma of the mitral valve.

An unusual case of localized amyloid light-chain (AL) amyloidosis and extramedullary plasmacytoma of the mitral valve is described. The worsening of a mitral regurgitation led to investigations and surgery. The valve presented marked distortion and thickening by type AL amyloid associated with a monotypic CD138+ immunoglobulin lambda plasma cell proliferation. Systemic staging showed a normal bone marrow and no evidence of amyloid deposition in other localizations. The patient's outcome after mitral valve replacement was excellent. To our knowledge, this is the first description of a localized AL amyloidosis as well as of a primary extramedullary plasmacytoma of the mitral valve.