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Background: The quality of a myocardial protection of a single-dose del Nido cardioplegia versus multiple dose blood-based cardioplegia on myocardial injury, outcomes and operative times in patients undergoing minimally invasive aortic valve replacement is basically unreported., Methods and Results: Preoperative and post-operative data, as well as technical details from isolated minimally invasive aortic valve replacements, performed using single-dose or multiple-dose cardioplegia were prospectively collected and retrospectively analysed. A total of 110 patients undergoing minimally invasive valve replacements at our institution composed two groups: 55 patients in the blood cardioplegia group (BloCa) and 55 in the del Nido group (DeNiCa). The two-matched groups were comparable in terms of preoperative variables. In the DeNiCa group, there was a statistically significant less need for cardiac defibrillation after aortic cross-clamp release ( p  < 0.001). Moreover, the BloCa group received intraoperatively more blood transfusions ( p  = 0.001) and more insulin administration for higher glucose levels ( p  < 0.001). The BloCa group showed higher intraoperative lactate levels ( p  = 0.01). Need for post-operative inotropic and vasoactive support, Creatine Kinase-MB levels after 6 and 12 h, onset of post-operative atrial fibrillation and length of stay were similar. No deaths occurred in neither groups., Conclusion: Single-dose del Nido cardioplegia in the setting of minimally invasive aortic surgery seems to offer adequate myocardial protection, comparable to multiple dose hematic cardioplegia. It has been documented a lower peri-operative need of defibrillation after cross-clamp release, lactate- and glucose peak values, as well as less blood transfusions compared to blood cardioplegic strategy., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Decellularized porcine aortic valve conduits (AVCs) implanted in a Vietnamese Pig (VP) experimental animal model were matched against decellularized and then cryopreserved AVCs to assess the effect of cryopreservation on graft hemodynamic performance and propensity to in vivo repopulation by host's cells. VPs (n = 12) underwent right ventricular outflow tract substitution using AVC allografts and were studied for 15-month follow-up. VPs were randomized into two groups, receiving AVCs treated with decellularization alone (D; n = 6) or decellularization/cryopreservation (DC; n = 6), respectively. Serial echocardiography was carried out to follow up hemodynamic function. All explanted AVCs were processed for light and electron microscopy. No signs of dilatation, progressive stenosis, regurgitation, and macroscopic calcification were echocardiographically observed in both D and DC groups. Explanted D grafts exhibited near-normal features, whereas the presence of calcification, inflammatory infiltrates, and disarray of elastic lamellae occurred in some DC grafts. In the unaltered regions of AVCs from both groups, almost complete re-endothelialization was observed for both valve cusps and aorta walls. In addition, side-by-side repopulation by recipient's fibroblasts, myofibroblasts, and smooth muscle cells was paralleled by ongoing tissue remodeling, as revealed by the ultrastructural identification of typical canals of collagen fibrillogenesis and elastogenesis-related features. Incipient neo-vascularization and re-innervation of medial and adventitial tunicae of grafted aortic walls were also detected for both D and DC groups. Cryopreservation did not affect post-implantation AVC hemodynamic behavior and was topically propensive to cell repopulation and tissue renewal, although graft deterioration including calcification was present in several areas. Thus, these preliminary data provide essential information on feasibility of decellularization and cryopreservation coupling in the perspective of treatment optimization and subsequent clinical trials using similarly treated human allografts as innovative heart valve substitutes.

Introduction: Redo surgery still is the treatment of choice for degenerated bioprosthesis. However, as far as elderly patients with concomitant comorbidities are concerned, the standard reoperation carries additional operative risks and, therefore, minimally invasive procedures must be prioritized., Areas Covered: During the last ten years, transcatheter procedures in native valves have become a standard technique in several centers with excellent procedural and mid-term results. Similarly, implantation of transcatheter stent-valves within degenerated aortic and mitral bioprosthesis, the 'valve-in-valve' procedure (V-in-V), represents a valid alternative to redo surgery in patients with high-risk surgical profiles. New challenges for V-in-V are the transcatheter stent-valve deployment in hostile targets (stented bioprosthesis with externally mounted leaflets, stentless valves, small bioprostheses), and avoid complications as delayed atrial embolization of mitral implantation and V-in-V thrombosis. Moreover a continuous ameliorated design of the devices on the market and new transcatheter stent-valves are recently developed in order to improve the outcome and safety of V-in-V treatment. Expert commentary: We reviewed the clinical outcomes and the procedural details of published transcatheter aortic and mitral valve-in-valve series focusing, in particular, on data from the Valve-in-Valve International Data registry (VIVID), and we provide a practical guide for valve sizing and stent-valve positioning.

Surgery for congenital valve anomalies in children is a challenging topic. We aim to assess early and late functional outcomes of CorMatrix scaffold after repair of aortic and pulmonary valves (PV) in congenital heart disease in a prospective nonrandomized clinical study on children with congenital aortic (Group 1) or PV (Group 2) disease. Primary endpoints were reoperation or reintervention on semilunar valves and echocardiographic evidence of regurgitation or stenosis greater than mild. Results of PV repair in tetralogy of Fallot were compared with a control group of patients who underwent PV repair with polytetrafluoroethylene. A total of 22 consecutive selected patients with complex congenital heart disease were included: PV repair in 18 and aortic valve repair in 4. At discharge bidimensional echocardiography, semilunar valve regurgitation was mild in 50% of all patients. At a median follow-up of 23 months (4.3-51.3), reoperation for aortic valve replacement was necessary in 2; right ventricular outflow tract obstruction occurred in 3, requiring interventional treatment in 2. Pulmonary regurgitation degree worsened in most patients of Group 2 at follow up. When comparing patients with tetralogy of Fallot in Group 2 with patients who underwent PV repair with polytetrafluoroethylene, there were no significant differences in PV function at follow up. We conclude that CorMatrix scaffold for semilunar valve reconstruction does not present with significant advantages to traditional materials at mid term follow up. In addition, when used for pulmonary valve reconstruction, CorMatrix seems to show gradual functional deterioration in the mid term., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Tissue engineering of heart valves investigates the possibility to create a fully compatible and biomimetic graft able to provide host cell repopulation like the native living valve. Decellularized aortic and pulmonary valves and synthetic polymers have been used to promote the creation of a native-like scaffold suitable to be colonized by cells either in vitro, in dynamic bioreactors or in vivo using different animal models. The herein presented research provides the intra-operative protocol and details of surgical technique. Porcine aortic valve conduits were decellularized and implanted in the right ventricular outflow tract of Vietnamese pigs.

Introduction: Aortic and mitral bioprosthesis are the gold standard treatment to replace a pathological native valve. However, bioprostheses are prone to structural valve degeneration, resulting in limited long-term durability. During the past decade, the implantation of transcatheter stent-valves within degenerated aortic and mitral bioprostheses, (the so-called 'valve-in-valve' procedure), represents a valid alternative to redo surgery in patients with high-risk surgical profiles. Areas covered: We reviewed the clinical outcomes and the procedural details of transcatheter aortic and mitral valve-in-valve series according to current published literature and include a practical guide for valve sizing and stent-valve positioning and strategies to prevent complications. Expert opinion: In both aortic and mitral positions meticulous planning is fundamental in these procedures to avoid serious complications including patient prosthesis mismatch, coronary obstruction and left ventricular outflow tract obstruction. [ABSTRACT FROM AUTHOR]