Bradley Munt

Percutaneous closure of prosthetic paravalvular leaks: Case series and review

Paravalvular leaks (PVLs) are a well‐recognized complication of prosthetic valve replacement. Most are asymptomatic and benign, but some may cause symptoms due to a large regurgitant volume or hemolysis. Medical therapy is palliative, while reoperation carries significant morbidity and mortality. Percutaneous transcatheter closure techniques, now routinely applied in the management of pathological cardiac and vascular communications, may be adaptable to PVL closure, potentially offer symptomatic relief.

Computed tomography-based sizing recommendations for transcatheter aortic valve replacement with balloon-expandable valves: Comparison with transesophageal echocardiography and rationale for implementation in a prospective trial.

BACKGROUND Computed tomography (CT) annular measurements are predictive of paravalvular regurgitation after transcatheter aortic valve replacement (TAVR) which is a predictor of mortality and morbidity. OBJECTIVES To demonstrate the rationale and potential implications of new CT sizing recommendations for TAVR. METHODS The CT sizing recommendations aim to ensure routine transcatheter heart valve (THV) oversizing of the aortic annular area [(THV external area/systolic annular area - 1) × 100; range, 1%-20%; target, 10%-15%]. Consecutive patients (n = 120) underwent CT before TAVR with balloon-expandable valves sized by transesophageal echocardiography (TEE). Retrospectively, the CT-recommended THV size was compared with the actual size implanted. RESULTS Compared with TEE, application of the newly developed CT-based sizing recommendations would have led to implantation of a larger valve in 33.3% (40/120), no change in valve size in 55.8% (67/120), and a smaller valve in 10.8% (13/120). In patients when CT recommended a larger valve, the incidence of at least moderate paravalvular regurgitation was 25% (10/40) compared with 4.5% (3/67; P < 0.01) when both TEE and CT recommendations were in agreement. Using diastolic versus systolic CT measurements results in 20% of patients receiving smaller THVs. TEE sizing resulted in 33.3% (40/120) of valves being undersized (THV area < CT systolic annular area) with a mean annular oversizing of 9.4% ± 17.4% (range: -21.5% to 65.9%) without annular rupture. In contrast, the CT sizing recommendations results in mean annular oversizing of 13.9% ± 8.0% (range, 1.3%-29.8%). CONCLUSION These CT sizing recommendations enable standardized moderate overexpansion of the aortic annulus. Clinical outcomes from these recommendations are being prospectively assessed in a multicenter trial.

Off-Pump Implantation of the HeartWare HVAD Left Ventricular Assist Device Through Minimally Invasive Incisions

Implantation of left ventricular assist devices through small incisions, avoiding cardiopulmonary bypass, may decrease the activation of the inflammatory and coagulation cascades and decrease bleeding and vasoplegia. One patient with severe, inotrope-dependant cardiomyopathy received the HeartWare left ventricular assist device (HeartWare Inc, Framingham, MA) through an upper ministernotomy and left minithoracotomy. The outflow graft was connected to the ascending aorta, and the inflow of the left ventricular assist device was attached through to the apex of the heart. The apical puncture was performed under rapid ventricular pacing, followed by insertion of the inflow of the pump. The patient was extubated rapidly and discharged home 14 days later.

Techniques for percutaneous closure of prosthetic paravalvular leaks.

Percutaneous transcatheter closure techniques are now routinely applied in the management of atrial and ventricular septal defects, patent ductus arteriosus, and other pathological cardiac and vascular communications. Recently, these same techniques have been applied to paravalvular defects. Reports are few; success variable and techniques vary widely. We review the current considerations and techniques of percutaneous transcatheter closure of paravalvular leaks.

Percutaneous stent-mounted valve for treatment of aortic or pulmonary valve disease

The objective of this study was to develop a prosthetic cardiac valve designed for percutaneous transcatheter implantation. Percutaneous catheter‐based therapies play a limited role in the management of cardiac valve disease. Surgical implantation of prosthetic valves usually requires thoracotomy and cardiopulmonary bypass. The stent‐valve is constructed of a rolled sheet of heat‐treated nitinol. Although malleable when cooled, once released from a restraining sheath at body temperature the stent unrolls, becomes rigid, and assumes its predetermined cylindrical conformation. A ratcheting lock‐out mechanism prevents recoil and external protrusions facilitate anchoring. Valve leaflets are constructed of bovine pericardium. The feasibility of catheter implantation, prosthetic valve function, and survival were investigated in an animal model. In vitro and pulse duplicator testing documented valve durability. Endovascular delivery of the prototype stent‐valve to the aortic or pulmonary position was feasible. Accurate positioning was required to ensure exclusion of the native valve leaflets and, in the case of the aortic valve, to avoid compromise of the coronary ostia or mitral apparatus. Oversizing of the stent in relation to the valve annulus was desirable to facilitate anchoring and prevent paravalvular insufficiency. Stent‐valve implantation proved feasible and compatible with survival in an animal model. Transcatheter implantation of prosthetic valves is possible. Further evolution of this technology will involve lower‐profile devices with design features that facilitate vascular delivery, visualization, positioning, deployment, and valvular function. Catheter Cardiovasc Interv 2004;63:89–93.

Canadian guidelines for training in adult perioperative transesophageal echocardiography : Recommendations of the cardiovascular section of the canadian Anesthesiologists' society and the canadian society of echocardiography

PurposeTo establish Canadian guidelines for training in adult perioperative transesophageal echocardiography (TEE).MethodsGuidelines were established by the Canadian Perioperative Echocardiography Group with the support of the cardiovascular section of the Canadian Anesthesiologists’ Society (CAS) in conjunction with the Canadian Society of Echocardiography.Guidelines for training in echocardiography by the American Society of Echocardiography, the American College of Cardiology and the Society of Cardiovascular Anesthesiologists were reviewed, modified and expanded to produce the 2003 Quebec expert consensus for training in perioperative echocardiography. The Quebec expert consensus and the 2005 Guidelines for the provision of echocardiography in Canada formed the basis of the Canadian training guidelines in adult perioperative TEE.ResultsBasic, advanced and director levels of expertise were identified. The total number of echocardiographic examinations to achieve each level of expertise remains unchanged from the 2002 American Society of Echocardiography-Society of Cardiovascular Anesthesiologists guidelines. The increased proportion of examinations personally performed at basic and advanced levels, and the level of autonomy at the basic level suggested by the Quebec expert consensus are retained. These examinations can be performed in a perioperative setting and are not limited to intraoperative TEE. Training “on the job”, the role of the perioperative transesophageal echocardiography examination, requirements for maintenance of competence, and duration of training are also discussed for each level of training. The components of a TEE report and comprehensive TEE examination are also outlined.ConclusionThe Canadian guidelines for training in adult perioperative TEE reflect the unique Canadian practice profile in perioperative TEE and address the training requirements to obtain expertise in this field.RésuméObjectifÉtablir des lignes directrices canadiennes pour la formation à l’échocardiographie transœsophagienne (ETO) chez l’adulte.MéthodeLes lignes directrices ont été établies par le Groupe canadien sur l’échocardiographie périopératoire, appuyé par la section cardiovasculaire de la Société canadienne des anesthésio-logistes (SCA) conjointement avec la Société canadienne d’écho-cardiographie. Nous avons passé en revue, modifié et développé les lignes directrices de l’American Society of Echocardiography, l’American College of Cardiology et la Society of Cardiovascular Anesthesiologists pour en arriver au consensus d’experts du Québec en 2003 sur la formation en échocardiographie périopératoire. Le consensus d’experts du Québec et les lignes directrices de 2005 sur l’utilisation de l’échocardiographie au Canada ont formé la base des lignes directrices de la formation canadiennes en ETO périopératoire chez l’adulte.RésultatsLes niveaux de compétence élémentaire, avancé et supérieur ont été déterminés. Le nombre total d’examens d’échocardiographie nécessaires pour atteindre chaque niveau de compétence est demeuré inchangé depuis les lignes directrices de 2002 de l’American Society of Echocardiography-Society of Cardiovascular Anesthesiologists. Nous avons conservé le nombre croissant d’examens réalisés personnellement aux niveaux élémentaire et avancé et le degré d’autonomie au niveau élémentaire suggérés par le consensus d’experts québécois. Ces examens peuvent être réalisés dans un contexte périopératoire et ne sont pas limités à l’ETO peropératoire. La formation «en milieu de travail», le rôle de l’examen d’échocardiographie transœsophagienne périopératoire, les exigences du maintien de la compétence et la durée de la formation sont aussi discutées pour chaque niveau de formation. La composante d’un rapport d’ETO et l’examen d’ETO détaillé sont décris des Guidelines for the Provision of Echocardiography in Canada.ConclusionLes lignes directrices canadiennes pour la formation à l’ETO périopératoire chez l’adulte représentent le profil particulier de la pratique canadienne en ETO périopératoire et traitent des exigences nécessaires pour acquérir des compétences dans le domaine.

Transcutaneous aortic valve implantation--a first line treatment for aortic valve disease?

Transcutaneous aortic valve implantation (TAVI) is rapidly gaining acceptance as a viable alternative to open-heart surgery aortic valve replacement (SAVR) in high-risk surgical candidates with aortic stenosis. To date, there have been reports on the procedural success, early mortality, and short-term and intermediate-term clinical outcomes, but there are limited data on long-term outcomes of TAVI. The study by Bauer et al in this issue of JASE adds to the accumulating evidence base with the echocardiographic experience of the longest follow-up after TAVI for aortic stenosis with the Sapien series of balloon expandable aortic prostheses (Edwards Lifesciences, Irvine, CA).