Effects of Leaflet Design on Transvalvular Gradients of Bioprosthetic Heart Valves.

Bioprosthetic aortic valves (BAVs) are becoming the prostheses of choice in heart valve replacement. The objective of this paper is to assess the effects of leaflet geometry on the mechanics and hemodynamics of BAVs in a fluid structure interaction model. The curvature and angle of leaflets were varied in 10 case studies whereby the following design parameters were altered: a circular arch, a line, and a parabola for the radial curvature, and a circular arch, a spline, and a parabola for the circumferential curvature.

Quicker yet safe: skeletonization of 1640 internal mammary arteries with harmonic technology in 965 patients.

Objectives: Skeletonization of the internal mammary artery (IMA) facilitates arterial grafting and has been shown to reduce deep sternal infection but is more time-consuming and tedious than pedicle harvest. We wished to determine if use of harmonic technology (HT) facilitates skeletonization of the IMA and is as safe as the conventional technique of skeletonization.

Methods: In a consecutive series of 1057 patients with isolated coronary artery bypass graft (CABG) surgery from 2003 to 2013, adverse events and recorded harvest times were compared between harmonic (965 patients) and non-harmonic patients (86 patients).

Canadian cardiac surgeons' perspectives on biomedical innovation.

Barriers to successful innovation can be identified and potentially addressed by exploring the perspectives of key stakeholders in the innovation process. Cardiac surgeons in Canada were surveyed for personal perspectives on biomedical innovation. Quantitative data was obtained by questionnaire and qualitative data via interviews with selected survey participants.

Cell therapy limits myofibroblast differentiation and structural cardiac remodeling: basic fibroblast growth factor-mediated paracrine mechanism.

Background: Experimental cell therapy attenuates maladaptive cardiac remodeling and improves heart function. Paracrine mechanisms have been proposed. The effect of cell therapy on post infarction cardiac fibroblast and extracellular matrix (ECM) regulation was examined.

Kryptonite bone cement prevents pathologic sternal displacement.

Background: Wire cerclage closure of sternotomy is the standard of care despite evidence of pathologic sternal displacement (> 2 mm) during physiologic distracting forces (coughing). Postoperative functional recovery, respiration, pain, sternal dehiscence, and infection are influenced by early bone stability. This translational research report provides proof-of-concept (part A) and first-in-man clinical data (part B) with use of a triglyceride-based porous adhesive to rapidly enhance the stability of conventional sternal closure.

Resident and bone marrow-derived mesenchymal stem cells in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is a major healthcare problem worldwide affecting more than half a million patients each year. Despite considerable advances in the treatment of HNSCC, a high rate of recurrences aggravates the clinical situation and disease outcomes have only modestly improved. Recent insights show that cancer is not only a disease of the transformed epithelium but is also influenced and dependent on its stromal environment.

Genipin blues: an alternative non-toxic crosslinker for heart valves?

Background And Aim Of The Study: One approach in tissue-engineering involves the implantation of decellularized, xenogenic scaffolds, with the expectation of repopulation in vivo. However, a major limitation of this method is the propensity to induce a strong immune host response. The study aim was to mitigate this immunogenicity by employing a crosslinking treatment with genipin.

Sustained release and activation of the growth factor basic fibroblast growth factor from loaded scaffolds in heart valve tissue engineering.

Objectives: Loading of biological matrices offers an opportunity to induce specific cell behaviour. We previously reported the use of growth factors to promote cell invasion and proliferation in tissue valve engineering. We investigated biological matrices preloaded with heparin as an ionically attractive template for the binding, activation and sustained release of basic fibroblast growth factor (bFGF).

Differential impact of TGF-beta and EGF on fibroblast differentiation and invasion reciprocally promotes colon cancer cell invasion.

Several studies indicate that cancer-associated fibroblasts play a critical role in cancer cell invasion and metastasis, the hallmarks of malignancy. To better understand the mechanisms underlying such effects, we established a heterotypic model of human fibroblasts (primary colon fibroblasts and immortalized human dermal fibroblasts) in co-culture with human colon cancer cells (HCT-8/E11), using three-dimensional collagen type-I and Matrigel matrices. We report that TGF-beta is the unique and dominant factor to provide pro-invasive signals to HCT-8/E11 colon cancer cells from TGF-beta-treated human fibroblasts in three-dimensional collagen type I and Matrigel matrices.

Acellular porcine and kangaroo aortic valve scaffolds show more intense immune-mediated calcification than cross-linked Toronto SPV valves in the sheep model.

Aim Of The Study: A major limitation of currently available bioprosthetic valves is their propensity to calcify. At present, one approach in tissue-engineering, uses decellularized, xenogenic scaffolds that are implanted, with the expectation of complete matrix repopulation in vivo. Whether or not such a decellularized matrix will be sufficiently endowed to prevent calcification is unknown.

Autologous glue: part of the sticky mystery unraveled.

Objective: The aim of the study was to evaluate the safety and efficacy of an autologous surgical tissue adhesive.

Methods: Autologous glue was made out of canine concentrated plasma proteins mixed with 7.5% glutaraldehyde.

Growth factor modulation of fibroblast proliferation, differentiation, and invasion: implications for tissue valve engineering.

We have previously shown that transforming growth factor-beta1 (TGF-beta1) stimulates transdifferentiation of fibroblasts into smooth muscle alpha-actin (alpha-SMA) positive myofibroblasts. However, TGF-beta, as such, is unsuitable for effective population of a heart valve matrix, because it dose-dependently inhibits growth of fibroblasts. The aim of this study was to investigate combinations of other growth factors with TGF-beta to stimulate the proliferation of suitably differentiated cells and to enhance their invasion into aortic valve matrices.

Readily available porcine aortic valve matrices for use in tissue valve engineering. Is cryopreservation an option?

The clinical use of acellular biological valves as scaffolds in tissue valve engineering would require them to be readily available. This study examines the feasibility of cryopreserving porcine aortic valve matrices for use in tissue valve engineering. Matrices prepared using an enzymatic-detergent decellularization protocol were examined before and after cryopreservation.

Hydrodynamic evaluation of kangaroo aortic valve matrices for tissue valve engineering.

We evaluated the hydrodynamic performance of kangaroo aortic valve matrices (KMs) (19, 21, and 23 mm), as potential scaffolds in tissue valve engineering using a pulsatile left heart model at low and high cardiac outputs (COs) and heart rates (HRs) of 60 and 90 beats/min. Data were measured in two samples of each type, pooled in two CO levels (2.1 +/- 0.

Scanning electron microscopic surface topography of ablation catheter perforations and calcific tear in an explanted bioprosthetic heart valve.

The authors report a triplet of leaflet destruction in a bioprosthetic aortic valve explanted at 12 years after iatrogenic ablation catheter perforation in a patient who underwent coronary artery bypass surgery and multiple ablative procedures in the interim. Lesions were examined topographically by scanning electron microscopy. Calcium content was evaluated by mass spectrometry and Von Kossa staining.

Bovine glue (BioGlue) is catabolized by enzymatic reaction in the vascular dog model.

Purpose: The aim of the study is to explore the feasibility, patency, and histologic changes of a sutureless vascular anastomotic technique using biological glue as sole fixation method.

Description: Eight mongrel dogs (+/-15 kg) underwent direct reanastomosis of their transsected iliac arteries. Both ends were placed on a 5-mm balloon and the anastomosis was secured with biological glue (BioGlue, Cryolife, Kennesaw, GA).

Transforming growth factor-beta-induced transition of fibroblasts: a model for myofibroblast procurement in tissue valve engineering.

Background And Aim Of The Study: The selection of a suitable cell type for scaffold seeding, its isolation and adequate expansion in vitro remains a major challenge in tissue valve engineering. The study aim was to establish a model for efficient procurement of myofibroblasts for in-vitro seeding using fibroblasts as progenitor cells.

Methods: Dermal and arterial mesenchymal cells from human (hDMC1.