Comparison of Two Miniaturized Cardiopulmonary Bypass Systems Regarding Inflammatory Response.

Cardiopulmonary bypass (CPB) is a known mediator of systemic inflammatory response. Extracorporeal circulations are undergoing continuous modifications and optimizations to achieve better results. Hence we aim to compare the inflammatory response associated with two recent miniature extracorporeal circulation systems during normothermic CPB. We measured plasma levels of cytokines including interleukin (IL)-1ß, IL-6, IL-10, tumor necrosis factor-α, migration inhibitory factor (MIF), receptor for advanced glycation endproduct, and cluster of differentiation 40 ligand in 60 consecutive patients during the first 24 h after CPB. The patients were prospectively randomized to one of three trial groups: patients in group A were operated with the minimal extracorporeal circulation circuit (MECC, Maquet, Rastatt, Germany), group B operated with the extracorporeal circulation circuit optimized (ECC.O, Sorin, Italy), and group C operated with a conventional extracorporeal circuit (CECC, Maquet). Arterial blood samples were collected at intervals before, 30 min after initiation, and after termination of CPB. Further samples were collected 6 and 24 h after CPB. IL-10 levels were significantly raised in the CECC group as compared with either of the mini ECC-circuits with a peak concentration at 6 h postoperatively. Human MIF concentrations were significantly higher in the CECC group starting 30 min after CPB and peaking at the end of CPB. The overall reduction in cytokine concentrations in the mini-ECC groups correlated with a lower need for blood transfusion in MECC and a shorter mechanical ventilation time for ECC.O. Normothermic CPB using minimally invasive extracorporeal circulation circuits can reduce the inflammatory response as measured by cytokine levels, which may be beneficial for perioperative preservation of pulmonary function and hemostasis in low risk patients.

Perfusion-Decellularization of Porcine Lung and Trachea for Respiratory Bioengineering.

Decellularization of native organs may provide an acellular tissue platform for organ regeneration. However, decellularization involves a trade-off between removal of immunogenic cellular elements and preservation of biomechanical integrity. We sought to develop a bioartificial scaffold for respiratory tissue engineering by decellularization of porcine lungs and trachea while preserving organ architecture and vasculature. Lung-trachea preparations from 25 German Landrace pigs were perfused in a modified Langendorff circuit and decellularized by an SDC (sodium deoxycholate)-based perfusion protocol. Decellularization was evaluated by histology and fluorescence microscopy, and residual DNA quantified spectrophotometrically and compared with controls. Airway compliance was evaluated by endotracheal intubation and mechanical ventilation to simulate physiological breathing-induced stretch. Structural integrity was evaluated by bronchoscopy and biomechanical stress/strain analysis by measuring passive tensile strength, all compared with controls. Decellularized lungs and trachea lacked intracellular components but retained specific collagen fibers and elastin. Quantitative DNA analysis demonstrated a significant reduction of DNA compared with controls (32.8 ± 12.4 µg DNA/mg tissue vs. 179.7 ± 35.8 µg DNA/mg tissue, P < 0.05). Lungs and trachea decellularized by our perfusion protocol demonstrated increased airway compliance but preserved biomechanical integrity as compared with native tissue. Whole porcine lungs-tracheae can be successfully decellularized to create an acellular scaffold that preserves extracellular matrix and retains structral integrity and three-dimensional architecture to provide a bioartifical platform for respiratory tissue engineering.

Gender differences in continuous-flow left ventricular assist device therapy as a bridge to transplantation: a risk-adjusted comparison using a propensity score-matching analysis.

The purpose of this study was to evaluate gender differences regarding outcome after continuous-flow left ventricular assist device (cfLVAD) implantation. The study was a retrospective review of prospectively collected data. Included were 24 consecutive female cfLVAD recipients and 24 male recipients (62.5% HeartMate II, 37.5% HeartWare) who received their devices between July 2007 and May 2013. Subjects were matched using propensity score analysis based on age, diagnosis, body surface area, preoperative mechanical circulatory support, heart failure severity score (INTERMACS class), and comorbidities. Female patients were significantly sicker before operation. After propensity score matching, there were no statistically significant differences in demographics or clinical baseline characteristics between male and female LVAD recipients. Also, there was a trend towards a longer postoperative intensive care unit stay in the female group (median 9 days [interquartile range 5-17] versus 15 days [interquartile range 8-33]; P < 0.061) and higher postoperative bilirubin values (median 14 mmol/L [interquartile range 10-17] versus 21 mmol/L [interquartile range 13-30]). However, there were no significant differences between the two groups in terms of outcome (P < 0.569). The overall survival was comparable between the two groups (log rank P < 0.389). Half (50%) of female patients required inotropic support for more than 7 days compared with 21.7% in the male group (P < 0.048). Half (50%) of female recipients required short-term postoperative right ventricular assist device implantation compared with 16.7% in the male group (P < 0.014). In conclusion, cfLVAD implantation as a bridge to transplantation is associated with longer duration of inotropic support and higher requirement for postoperative mechanical right ventricular support in women with similar survival rates. Further studies are required to identify additional demographic and clinical factors that modulate outcomes and will enhance the ability to risk-stratify cfLVAD recipients.

Minimally invasive HeartWare LVAD implantation through single left thoracotomy.

Left ventricular assist device (LVAD) is now a routine therapy for advanced heart failure. Authors demonstrate a novel technique of LVAD implantation through a single left thoracotomy with anastomosis of outflow graft to the arch of aorta. The technique avoids sternotomy or additional right thoracotomy, keeps ascending aorta clear and puts outflow graft away from the sternum.

The Thebesian valve: Gatekeeper to the coronary sinus.

Clinical cardiac procedures such as electrophysiology studies, catheter ablation of arrhythmias, retrograde cardioplegia delivery, cardiac resynchronization therapy and, more recently, percutaneous mitral annuloplasty, involve cannulation of the coronary sinus (CS). The presence of a membrane closing the orifice of the CS may cause difficulties during these interventions. Thus, detailed knowledge of the variations and anomalies of the valve of the CS, or the Thebesian valve, now has practical significance. To improve our understanding of this structure, classic anatomical dissection of 50 hearts from dissection room cadavers was performed. A Thebesian valve was present in the overwhelming majority (88%) of cases. Its morphology varied widely, from a few small strands of tissue, to a membrane covering more than half the CS ostium. A significant number (20%) of valves occluded >65% of the ostium, making them "potential complicating factors" in cannulation of the CS. An understanding of these anatomical variations may help in identifying and overcoming potential difficulties during clinical cardiac interventions.

Cardiac myxomas: experience over one decade.

BACKGROUND: This single-center study reviews our experience with cardiac myxomas over the past decade. METHODS: Sixty-two patients (23 male) with median age 38 years (range: 8 to 69 years) underwent excision of primary or recurrent cardiac myxomas between 2000 and 2009. Patients were evaluated with echocardiography preoperatively and annually postoperatively. Follow-up is current for all survivors (range 13 months to 10 years). RESULTS: Fifty-two patients had left atrial myxomas, seven right atrial, two biatrial, and one right ventricular. Three cases were familial. Maximum number of myxomas in a single patient was four. Symptom duration ranged from two to eight months. Two early deaths were due to low cardiac output and embolic cerebrovascular accident; one late death was due to a noncardiac cause. Actuarial survival was 96.8 ± 1.8% at 10 years. Most patients were asymptomatic following surgery. No sporadic, multiple, or biatrial myxomas recurred. Recurrence occurred in two familial cases, both with single, left atrial myxoma. Freedom from reoperation was 98.4 ± 1.3% at five years and 96.8 ± 1.8% at 10 years. CONCLUSIONS: Biatrial involvement or multiplicity of myxomas does not mandate recurrence. Surgical excision has excellent overall survival and freedom from reoperation rates, but annual follow-up including echocardiographic surveillance is recommended as familial cases tend to recur.

Concurrent Left Ventricular Assist Device (LVAD) Implantation and Percutaneous Temporary RVAD Support via CardiacAssist Protek-Duo TandemHeart to Preempt Right Heart Failure.

Right ventricular failure (RVF) is an unfortunate complication that continues to limit outcomes following durable left ventricular assist device (LVAD) implantation. Despite several 'RVF risk scores' having been proposed, preoperative prediction of post-LVAD RVF remains a guesstimate at best. Current strategies for institution of temporary RVAD support are invasive, necessitate additional re-thoracotomy, restrict postoperative mobilization, and/or entail prolonged retention of prosthetic material in-situ. The authors propose a novel surgical strategy comprising simultaneous implantation of a permanent LVAD and percutaneous TandemHeart® plus ProtekDuo® to provide temporary RVAD support and preempt RVF in patients with impaired RV function.

Does postoperative blood pressure influence development of aortic regurgitation following continuous-flow left ventricular assist device implantation?†.

OBJECTIVES: The true impact of postoperative blood pressure (BP) control on development of aortic regurgitation (AR) following continuous-flow left ventricular assist device (CF-LVAD) implantation remains uncertain. This study examines the influence of BP in patients with de novo AR following CF-LVAD implantation. METHODS: All patients with no or

Resolution of heart block after surgical correction of failed transcatheter aortic valve implantation.

Surgical aortic valve replacement is the gold standard therapy for severe aortic stenosis but transcatheter aortic valve implantation (TAVI) is increasingly employed in "high-risk" patients. Atrioventricular block and aortic regurgitation are frequent complications of nitinol-based stented valves. We report a case of successful, but complex reoperative surgery 13 days after failed TAVI with iatrogenic aortic and mitral regurgitation and new-onset heart block. Removal of a CoreValve prosthesis (Medtronic Inc, Minneapolis, MN) with standard aortic valve replacement resulted in restoration of sinus rhythm and valvular competencies.

Pyramid heart: uncommon sequel of a common disease.

A 40-year-old woman presented 19 years after ring-annuloplastyfor rheumatic mitral regurgitation. Long-standing rheumatic heartdisease resulted in an unusual finding on her chest radiograph.

Modified technique using Novalung as bridge to transplant in pulmonary hypertension.

Patients with idiopathic pulmonary artery hypertension in refractory right ventricular failure may decompensate acutely and die while on the lung transplantation waiting list. We describe such a patient bridged to lung transplantation with a modified surgical technique for left pulmonary artery-to-left atrium bypass using Novalung, a low-resistance diffusion membrane device.

Does CircuLite Synergy assist device as partial ventricular support have a place in modern management of advanced heart failure?

The discrepancy between the number of patients on the waiting list and available donor hearts has led to the successful development of left ventricular assist devices (LVAD) as a bridge to transplantation. The conventional LVADs are designed to provide full hemodynamic support for the end-stage failing heart. However, full-support LVAD implantation requires major surgery, sternotomy and cardiopulmonary bypass in majority of cases. The Synergy Micro-pump is the smallest implantable LVAD and provides partial flow support up to 3 l/min. It was shown that early intervention with this device can provide substantial benefits to patients with severe heart failure not yet sick enough for a full-support LVAD. Due the small dimensions it can be implanted without cardiopulmonary bypass or a sternotomy. The purpose of this article is to review the clinical use of the Synergy Micro-pump as partial hemodynamic support.

Preoperative predictors and outcomes of right ventricular assist device implantation after continuous-flow left ventricular assist device implantation.

OBJECTIVE: The outcomes of ventricular assist device therapy remain limited by right ventricular failure. We sought to define the predictors and evaluate the outcomes of right ventricular failure requiring right ventricular assist device support after long-term continuous-flow left ventricular assist device implantation. METHODS: Records of all continuous-flow left ventricular assist device recipients for the last 10 years were analyzed, including patients on preoperative intra-aortic balloon pump, extracorporeal membrane oxygenation, and short-term ventricular assist device support. Perioperative clinical, echocardiographic, hemodynamic, and laboratory data of continuous-flow left ventricular assist device recipients requiring right ventricular assist device support (right ventricular assist device group) were compared with the rest of the patient cohort (control group). RESULTS: Between July 2003 and June 2013, 152 patients underwent continuous-flow left ventricular assist device implantation as a bridge to transplantation. The overall postoperative incidence of right ventricular assist device support was 23.02% (n = 35). Right ventricular assist device implantation did not significantly affect eventual transplantation (P = .784) or longer-term survival (P = .870). Preoperative right ventricular diameter (P < .001), tricuspid annular plane systolic excursion (P < .001), previous sternotomy (P = .002), preoperative short-term mechanical support (P = .005), left atrial diameter (P = .014), female gender (P = .020), age (P = .027), and preoperative bilirubin levels (P = .031) were univariate predictors of right ventricular assist device implantation. Multivariate analysis revealed lesser tricuspid annular plane systolic excursion (P = .013; odds ratio, 0.613; 95% confidence interval, 0.417-0.901) and smaller left atrial diameter (P = .007; odds ratio, 0.818; 95% confidence interval, 0.707-0.947) as independent predictors of right ventricular assist device implantation. Receiver operating characteristic curve of tricuspid annular plane systolic excursion yielded an area under the curve of 0.85 (95% confidence interval, 0.781-0.923), with cutoff tricuspid annular plane systolic excursion less than 12.5 mm having 84% sensitivity and 75% specificity. CONCLUSIONS: Lesser tricuspid annular plane systolic excursion and smaller left atrial diameter are independent predictors of the need for right ventricular assist device support after continuous-flow left ventricular assist device implantation. Right ventricular assist device implantation does not adversely affect eventual transplantation or survival after continuous-flow left ventricular assist device implantation.

Bioartificial heart: a human-sized porcine model--the way ahead.

BACKGROUND: A bioartificial heart is a theoretical alternative to transplantation or mechanical left ventricular support. Native hearts decellularized with preserved architecture and vasculature may provide an acellular tissue platform for organ regeneration. We sought to develop a tissue-engineered whole-heart neoscaffold in human-sized porcine hearts. METHODS: We decellularized porcine hearts (n = 10) by coronary perfusion with ionic detergents in a modified Langendorff circuit. We confirmed decellularization by histology, transmission electron microscopy and fluorescence microscopy, quantified residual DNA by spectrophotometry, and evaluated biomechanical stability with ex-vivo left-ventricular pressure/volume studies, all compared to controls. We then mounted the decellularized porcine hearts in a bioreactor and reseeded them with murine neonatal cardiac cells and human umbilical cord derived endothelial cells (HUVEC) under simulated physiological conditions. RESULTS: Decellularized hearts lacked intracellular components but retained specific collagen fibers, proteoglycan, elastin and mechanical integrity; quantitative DNA analysis demonstrated a significant reduction of DNA compared to controls (82.6±3.2 ng DNA/mg tissue vs. 473.2±13.4 ng DNA/mg tissue, p<0.05). Recellularized porcine whole-heart neoscaffolds demonstrated re-endothelialization of coronary vasculature and measurable intrinsic myocardial electrical activity at 10 days, with perfused organ culture maintained for up to 3 weeks. CONCLUSIONS: Human-sized decellularized porcine hearts provide a promising tissue-engineering platform that may lead to future clinical strategies in the treatment of heart failure.

De novo aortic regurgitation after continuous-flow left ventricular assist device implantation.

BACKGROUND: Significant aortic regurgitation (AR) after continuous-flow left ventricular assist device (cf-LVAD) placement affects device performance and patient outcomes. This study examined the development of AR and long-term results after implantation of cf-LVADs. METHODS: The study included all patients with no or less than mild AR who underwent HeartMate II (58 [62%]; Thoratec Corp, Pleasanton, CA) or HeartWare (35 [38%]; HeartWare International, Framingham, MA) implantation at our institute from July 2006 to July 2012. Serial echocardiograms were obtained preoperatively, at 1, 3 and 6 months postoperatively, and then at a minimum of 4-month intervals in patients with longer-term support. Kaplan-Meier estimates for freedom from moderate or greater AR were generated. Logistic regression analysis was used to define independent predictors of AR after cf-LVAD implantation. RESULTS: Median duration of LVAD support was 527 days (25(th), 75(th): 289, 907; range, 60 to 2,433 days). Mild AR developed in 48 patients (51.6%) over a median duration of 126 days, with progression to moderate AR in 13 (14%) over 493 days and to severe AR in 2 (2.1%) over 1,231 days. The incidence of mild or greater AR was 43.1% in HeartMate II vs 65.7% in HeartWare recipients (p = 0.035). Overall freedom from moderate or greater AR was 94.7% ± 2.6% at 1 year, 86.9% ± 4.5% at 2 years, 82.8% ± 5.9% at 3 years, and 31% ± 16.9% at 4 years. Independent predictors of AR were duration of support (odds ratio, 1.002; 95% confidence interval, 1.000 to 1.004; p = 0.017) and a persistently closed aortic valve (odds ratio, 0.193; 95% confidence interval, 0.097 to 0.382; p < 0.001). CONCLUSIONS: AR is associated with longer cf-LVAD support duration and persistent aortic valve closure. Incidence of moderate or greater AR after cf-LVAD implantation increases significantly after 3 years. The clinical implications of these data may warrant consideration of prophylactic aortic valve replacement at the time of cf-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AR that is more than mild.