Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
J Vis Exp ; (183)2022 05 10.
Article in English | MEDLINE | ID: mdl-35635480

ABSTRACT

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ donor pool. However, the DCD process is associated with the risk of cardiac tissue injury due to the inevitable period of warm ischemia. Normothermic regional perfusion (NRP) allows for an in situ organ assessment, allowing the procurement of hearts determined to be viable. Here, we describe a clinically relevant large-animal model of DCD followed by NRP. Circulatory death is established in anesthetized pigs by stopping mechanical ventilation. After a preset warm ischemia period, an extracorporeal membrane oxygenator (ECMO) is used for a NRP period lasting at least 30 min. During this reperfusion period, the model allows the collection of various myocardial biopsies and blood samples for initial cardiac evaluation. Once NRP is weaned, biochemical, hemodynamic, and echocardiographic assessments of cardiac function and metabolism can be performed before organ procurement. This protocol closely simulates the clinical scenario previously described for DCD and NRP in heart transplantation and has the potential to facilitate studies aimed at decreasing ischemia-reperfusion injury and enhance cardiac functional preservation and recovery.


Subject(s)
Heart Transplantation , Tissue and Organ Procurement , Animals , Disease Models, Animal , Heart Transplantation/methods , Humans , Perfusion/methods , Swine , Tissue Donors
4.
Can J Anaesth ; 68(5): 661-671, 2021 May.
Article in English | MEDLINE | ID: mdl-33543427

ABSTRACT

Controlled donation after circulatory determination of death (DCD), where death is determined after cardiac arrest, has been responsible for the largest quantitative increase in Canadian organ donation and transplants, but not for heart transplants. Innovative international advances in DCD heart transplantation include direct procurement and perfusion (DPP) and normothermic regional perfusion (NRP). After death is determined, DPP involves removal and reanimation of the arrested heart on an ex situ organ perfusion system. Normothermic regional perfusion involves surgically interrupting (ligating the aortic arch vessels) brain blood flow after death determination, followed by restarting the heart and circulation in situ using extracorporeal membrane oxygenation. The objectives of this Canadian consensus building process by a multidisciplinary group of Canadian stakeholders were to review current evidence and international DCD heart experience, comparatively evaluate international protocols with existing Canadian medical, legal, and ethical practices, and to discuss implementation barriers. Review of current evidence and international experience of DCD heart donation (DPP and NRP) determined that DCD heart donation could be used to provide opportunities for more heart transplants in Canada, saving additional lives. Although candid discussion identified a number of potential barriers and challenges for implementing DCD heart donation in Canada, it was determined that DPP implementation is feasible (pending regulatory approval for the use of an ex situ perfusion device in humans) and in alignment with current medical guidelines for DCD. Nevertheless, further work is required to evaluate the consistency of NRP with current Canadian death determination policy and to ensure the absence of brain perfusion during this process.


RéSUMé: Le don contrôlé après un décès circulatoire (DDC), cas dans lequel le décès est déterminé après un arrêt cardiaque, est à l'origine de la plus forte augmentation quantitative des dons et des transplantations d'organes au Canada, sauf pour les transplantations cardiaques. Parmi les progrès internationaux novateurs dans la transplantation cardiaque après DDC, citons l'obtention directe et perfusion (ODP) et la circulation régionale normothermique (CRN). Une fois le décès déterminé, l'ODP consiste à retirer et réanimer le cœur arrêté sur un système de perfusion ex situ. La circulation régionale normothermique consiste à interrompre de manière chirurgicale (en ligaturant les vaisseaux de l'arc aortique) le flux sanguin au cerveau après la détermination du décès, puis à redémarrer le cœur et la circulation in situ utilisant l'oxygénation par membrane extracorporelle (ECMO). Les objectifs de ce processus canadien d'établissement de consensus par un groupe multidisciplinaire d'intervenants canadiens étaient d'examiner les données probantes et les expériences internationales actuelles en matière de DDC, d'évaluer comparativement les protocoles internationaux par rapport aux pratiques médicales, juridiques et éthiques canadiennes existantes, et de discuter des obstacles à la mise en œuvre de tels protocoles. L'examen des données probantes et des expériences internationales actuelles en matière de don de cœur après DDC (ODP et CRN) a permis de déterminer que le don de cœur après DDC pourrait être utilisé afin de faire de plus nombreuses transplantations cardiaques au Canada, sauvant ainsi des vies supplémentaires. Bien que des discussions aient permis d'identifier plusieurs obstacles et défis potentiels à la mise en œuvre du don cardiaque après DDC au Canada, il a été déterminé que la mise en œuvre de l'ODP est réalisable (en attente de l'approbation réglementaire pour l'utilisation d'un dispositif de perfusion ex situ chez l'humain) et en accord avec les directives médicales actuelles concernant le DDC. Néanmoins, d'autres travaux sont nécessaires pour évaluer la conformité de la CRN aux politiques canadiennes actuelles de détermination de la mort et pour garantir l'absence de perfusion cérébrale au cours de ce processus.


Subject(s)
Organ Preservation , Tissue and Organ Procurement , Canada , Consensus , Death , Humans , Perfusion , Tissue Donors
5.
Ann Thorac Surg ; 110(3): 863-869, 2020 09.
Article in English | MEDLINE | ID: mdl-32074501

ABSTRACT

BACKGROUND: The interactive relationship between left ventricular (LV) ejection fraction (LVEF) and LV size in predicting perioperative outcomes after cardiac surgery has not been clarified. METHODS: This study reviewed all patients who underwent cardiac surgery between 2010 and 2016 with either preserved LVEF (>60%; n = 5685) or severely reduced LVEF (<20%; n = 143). LV size was categorized by using either LV end-diastolic or end-systolic diameter or a qualitative assessment, as follows: normal, smaller than 4 cm; mildly enlarged, 4.1 to 5.4 cm moderately enlarged, 5.5 to 6.5 cm; and severely enlarged, larger than 6.5 cm. Using propensity-score analysis, we matched patients with LVEF less than 20% (n = 143) in a 3:1 ratio with patients with LVEF greater than 60% (n = 429). RESULTS: There were significant differences in mortality, major morbidity, and operative mortality and prolonged length of stay between patients with LVEF less than 20% and LVEF greater than 60%. In patients with LVEF less than 20%, there were no significant differences in outcomes between those with an LV size of 5.4 cm or smaller and an LV size of 5.5 cm or larger. In patients undergoing isolated coronary artery bypass grafting (CABG), LV size predicted mortality, major morbidity, and operative mortality (odds ratio, 5.5 [95% confidence interval, 2.0 to 15.7]; P < .001) and prolonged length of stay (odds ratio, 3.4 [95% confidence interval, 1.2 to 10.3]; P = .026), respectively. CONCLUSIONS: LVEF is more important than LV size in predicting outcomes after cardiac surgery. However, in patients undergoing isolated CABG, LV size has an interactive effect with LVEF and can potentially aid the decision-making process. Risk adjustment models using only LVEF may be inaccurate, particularly with respect to isolated CABG procedures.


Subject(s)
Coronary Artery Bypass/adverse effects , Coronary Artery Disease/surgery , Heart Ventricles/diagnostic imaging , Postoperative Complications , Stroke Volume/physiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, Left/physiology , Aged , Diastole , Echocardiography , Female , Heart Ventricles/physiopathology , Humans , Male , Middle Aged , Organ Size , Postoperative Period , Propensity Score , Retrospective Studies , Risk Factors , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/etiology
6.
JACC Case Rep ; 2(13): 2090-2094, 2020 Nov.
Article in English | MEDLINE | ID: mdl-34317114

ABSTRACT

Patients with restrictive or hypertrophic cardiomyopathy (HCM) are often ineligible for a left ventricular assist device (LVAD) due to the risk of suction events with a small left ventricular cavity size and left ventricular inflow cannula. We describe an alternative LVAD configuration using a left atrial inflow cannula as a bridge to transplantation in an adult with HCM. (Level of Difficulty: Advanced.).

7.
Am J Physiol Heart Circ Physiol ; 318(1): H25-H33, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31774696

ABSTRACT

Ex situ heart perfusion (ex situ heart perfusion) is an emerging technique that aims to increase the number of organs available for transplantation by augmenting both donor heart preservation and evaluation. Traditionally, ex situ heart perfusion has been performed in an unloaded Langendorff mode, though more recently groups have begun to use pump-supported working mode (PSWM) and passive afterload working mode (PAWM) to enable contractile evaluation during ex situ heart perfusion. To this point, however, neither the predictive effectiveness of the two working modes nor the predictive power of individual contractile parameters has been analyzed. In this article, we use our previously described system to analyze the predictive relevance of a multitude of contractile parameters measured in each working mode. Ten porcine hearts were excised and perfused ex situ in Langendorff mode for 4 h, evaluated using pressure-volume catheterization in both PSWM and PAWM, and transplanted into size-matched recipient pigs. After 3 h, hearts were weaned from cardiopulmonary bypass and evaluated. When correlating posttransplant measurements to their ex situ counterparts, we report that parameters measured in both modes show sufficient power (Spearman rank coefficient > 0.7) in predicting global posttransplant function, characterized by cardiac index and preload recruitable stroke work. For the prediction of specific posttransplant systolic and diastolic function, however, a large discrepancy between the two working modes was observed. With 9 of 10 measured posttransplant parameters showing stronger correlation with counterparts measured in PAWM, it is concluded that PAWM allows for a more detailed and nuanced prediction of posttransplant function than can be made in PSWM.NEW & NOTEWORTHY Ex situ heart perfusion has been proposed as a means to augment the organ donor pool by improving organ preservation and evaluation between donation and transplantation. Using our multimodal perfusion system, we analyzed the impact of using a "passive afterload working mode" for functional evaluation as compared with the more traditional "pump-supported working mode." Our data suggests that passive afterload working mode allows for a more nuanced prediction of posttransplant function in porcine hearts.


Subject(s)
Heart Transplantation , Myocardial Contraction , Perfusion , Ventricular Function, Left , Ventricular Pressure , Animals , Cardiac Catheterization , Diastole , Heart Transplantation/adverse effects , Isolated Heart Preparation , Male , Models, Animal , Perfusion/adverse effects , Predictive Value of Tests , Recovery of Function , Sus scrofa , Systole , Time Factors
8.
Am J Transplant ; 20(5): 1262-1271, 2020 05.
Article in English | MEDLINE | ID: mdl-31769924

ABSTRACT

Ischemia-reperfusion injury (IRI) and cardiac allograft vasculopathy (CAV) remain unsolved complications post-heart transplant (Tx). The antioxidant transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) has been suggested to inhibit reactive oxygen species-mediated NF-κB activation. We hypothesized that Nrf2 inhibits NF-κB activation post-Tx and suppresses IRI and the subsequent development of CAV. IRI and CAV were investigated in murine heterotopic Tx models, respectively. Nrf2 wild-type (WT) and KO mice were used as donors. Sulforaphane was used as an Nrf2 agonist. In saline-treated animals following 24 hours of reperfusion in isogenic grafts, Nrf2-KO showed significantly less SOD1/2 activity compared with WT. Nrf2-KO displayed significantly high total and phosphorylated p65 expressions and percentage of cells with nuclear p65. mRNA levels of NF-κB-mediated proinflammatory genes were also high. Graft dysfunction, apoptosis, and caspase-3 activity were significantly higher in Nrf2-KO. In the allograft studies, graft beating score was significantly weaker in Nrf2-KO compared with WT. Nrf2-KO also demonstrated significantly more coronary luminal narrowing. In WT animals, sulforaphane successfully augmented all the protective effects of Nrf2 with increase of SOD2 activity. Nrf2 inhibits NF-κB activation and protects against IRI via its antioxidant properties and suppresses the subsequent development of CAV.


Subject(s)
NF-E2-Related Factor 2 , Reperfusion Injury , Allografts , Animals , Mice , Mice, Inbred C57BL , NF-E2-Related Factor 2/genetics , NF-kappa B , Reperfusion Injury/prevention & control
9.
J Cardiothorac Vasc Anesth ; 34(8): 2189-2206, 2020 Aug.
Article in English | MEDLINE | ID: mdl-31753746

ABSTRACT

The gold standard treatment for end-stage heart failure, with 50% mortality within 5 years of diagnosis, is considered heart transplantation. Despite the improvements in immunosuppression, the period of highest mortality risk in the heart transplantation population is during the first year post-transplantation, with primary graft dysfunction being the leading cause of mortality. After adequate preoperative assessment of the recipient, including patients on mechanical support, the intraoperative care of heart transplantation patients requires extensive monitoring followed by proficient management of anesthesia induction and maintenance, ventilation, and fluid therapy. The focus on weaning from cardiopulmonary bypass should be on preventing right ventricular failure and high pulmonary vascular resistances, with protocolized blood conservation strategies and transfusion protocols. The early postoperative care of a heart transplantation patient is focused on the post-cardiopulmonary bypass and transplantation status, with particular attention to the presence of primary graft dysfunction, right ventricular performance, pulmonary pressures, and vasoplegia. The aim is early extubation, inotropic and chronotropic support weaning, and chest tube removal to facilitate discharge of the patient from the intensive care unit. The increased complexity of heart transplantation recipients, including the incremental use of pre- transplantation mechanical circulatory support and extended criteria donor hearts, requires extensive and sophisticated preparation of the cardiac anesthesiologist. This article aims to provide an overview of the intraoperative and early postoperative anesthesia management of heart transplantation patients.


Subject(s)
Anesthetics , Heart Failure , Heart Transplantation , Heart Failure/diagnosis , Heart Failure/therapy , Humans , Postoperative Complications/diagnosis , Postoperative Complications/therapy , Tissue Donors
10.
Cardiovasc Eng Technol ; 11(1): 96-110, 2020 02.
Article in English | MEDLINE | ID: mdl-31797263

ABSTRACT

PURPOSE: Windkessel impedance analysis has proven to be an effective technique for instituting artificial afterload on ex situ hearts. Traditional fixed parameter afterload modules, however, are unable to handle the changing contractile conditions associated with prolonged ex situ heart perfusion. In this paper, an adjustable afterload module is described comprising of three fully adjustable sub-components: a systemic resistor, a proximal resistor and a compliance chamber. METHODS: Using a centrifugal pump, the systemic resistor and compliance chamber were subjected to testing across their operating ranges, whereby the predictability of resistance and compliance values was evaluated. The components were then assembled, and the full module tested on three separate porcine hearts perfused for 6 h with success defined by the ability to maintain physiological systolic and diastolic aortic pressures across flow rate variability. RESULTS: For both the systemic resistor and compliance chamber, experimental measurements agreed with their theoretical equivalents, with coefficients of determination of 0.99 and 0.97 for the systemic resistor and compliance chamber, respectively. During ex situ perfusion, overall 95% confidence intervals demonstrate that physiological systolic (95-96.21 mmHg) and diastolic (26.8-28.8 mmHg) pressures were successfully maintained, despite large variability in aortic flow. Left ventricular contractile parameters, were found to be in line with those in previous studies, suggesting the afterload module has no detrimental impact on functional preservation. CONCLUSIONS: We conclude that due to the demonstrable control of our afterload module, we can maintain physiological aortic pressures in a passive afterload working mode across prolonged perfusion periods, enabling effective perfusion regardless of contractile performance.


Subject(s)
Aorta/physiopathology , Arterial Pressure , Models, Cardiovascular , Myocardial Contraction , Perfusion , Ventricular Function, Left , Animals , Compliance , Elastic Modulus , Isolated Heart Preparation , Male , Models, Animal , Sus scrofa , Time Factors
11.
J Vis Exp ; (146)2019 04 27.
Article in English | MEDLINE | ID: mdl-31081813

ABSTRACT

Fifty-years following the first successful report, cardiac transplantation remains the gold-standard treatment for eligible patients with advanced heart failure. Multiple small-animal models of heart transplantation have been used to study the acute and long-term effects of novel therapies. However, few are tested and demonstrated success in clinical trials. It is of critical importance to evaluate new therapies in a clinically relevant large-animal model for efficient and reliable translation of basic studies' findings. Here, we describe a pre-clinical large-animal (porcine) model of orthotopic heart transplantation that has been firmly established and previously used to investigate novel cardioprotective strategies. This procedure focuses on acute ischemia-reperfusion injury and is a reliable method to investigate novel interventions which have been tested and validated in smaller experimental models, such as the murine model. We demonstrate its usefulness in assessing cardiac performance during the early post-transplantation period and other potential possibilities enabled by the model.


Subject(s)
Heart Transplantation , Animals , Disease Models, Animal , Electrocardiography , Hydrogen-Ion Concentration , Lactic Acid/metabolism , Male , Mice , Pressure , Reperfusion Injury/pathology , Swine
12.
Circ Heart Fail ; 12(4): e005364, 2019 04.
Article in English | MEDLINE | ID: mdl-30998401

ABSTRACT

BACKGROUND: There has been an increased interest in donation after circulatory death (DCD) to expand donor pool for cardiac transplantation. Normothermic regional perfusion (NRP) allows in situ assessment of DCD hearts, allowing only acceptable organs to be procured. We sought to determine if extended cold storage was possible for DCD hearts following NRP and to compare hearts stored using standard cold storage with a novel cardioprotective solution designed for room temperature storage. METHODS AND RESULTS: Donor pigs underwent hypoxic cardiac arrest (DCD) followed by 15 minutes of warm ischemia and resuscitation on NRP. They were then randomly assigned to static storage with histidine-tryptophan-ketoglutarate (HTK) at 4°C (HTK group, n=5) or SOM-TRN-001 at 21°C (SOM group, n=5). Conventional beating-heart donations were used as controls (n=4). Fourteen transplants were successfully performed. HTK hearts showed initial dysfunction following reperfusion; however, they demonstrated significant recovery up to 3 hours post-transplant. No significant differences were seen between HTK and control hearts post-transplantation (cardiac index: control 49.5±6% and HTK 48.5±5% of baseline). SOM improved myocardial preservation; hearts showed stable contractility after transplantation (cardiac index: 113.0±43% of NRP function) and improved diastolic function compared with HTK. Preservation in SOM also significantly reduced proinflammatory cytokine production and release following transplantation and partially prevented endothelial dysfunction. CONCLUSIONS: DCD hearts stored using a standard preservation solution demonstrated comparable post-transplantation myocardial function to standard controls. Thus, short periods of cold storage following successful NRP and documented adequate function is an acceptable strategy for DCD hearts. Preservation in SOM at room temperature is feasible and can improve cardiac recovery by minimizing endothelial dysfunction and tissue injury.


Subject(s)
Heart Failure/surgery , Heart Transplantation , Tissue Donors , Animals , Cardiac Surgical Procedures , Death , Heart , Heart Transplantation/methods , Male , Myocardium , Perfusion , Swine , Time Factors
13.
Ann Thorac Surg ; 108(3): e153-e155, 2019 09.
Article in English | MEDLINE | ID: mdl-30853593

ABSTRACT

A 58-year-old woman had medically refractory heart failure due to idiopathic dilated cardiomyopathy. She underwent tricuspid repair and left ventricular assist device implantation for inotropic-dependent heart failure. Because of severe right ventricular dysfunction, she experienced progressive bradycardia and ventricular asystole with electrocardiographic and echocardiographic standstill. Despite the lack of native cardiac activity, she maintained end-organ perfusion with inotropic support until she underwent successful transplantation. This report highlights a case of mechanical circulatory support with an isolated left ventricular assist device implantation even in the absence of native right ventricular function.


Subject(s)
Cardiotonic Agents/therapeutic use , Heart Failure/surgery , Heart Transplantation/methods , Heart-Assist Devices , Prosthesis Implantation/adverse effects , Ventricular Dysfunction, Right/diagnostic imaging , Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/drug therapy , Disease Progression , Echocardiography/methods , Electrocardiography/methods , Female , Graft Survival , Heart Failure/diagnostic imaging , Heart Failure/etiology , Humans , Middle Aged , Prognosis , Prosthesis Implantation/methods , Risk Assessment , Treatment Failure , Treatment Outcome , Ventricular Dysfunction, Right/surgery
14.
J Thorac Cardiovasc Surg ; 157(2): 615-625.e1, 2019 02.
Article in English | MEDLINE | ID: mdl-30121134

ABSTRACT

OBJECTIVE: Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation. METHODS: Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured. RESULTS: Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001). CONCLUSIONS: Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction.


Subject(s)
Coronary Vessels/physiopathology , Endothelium, Vascular/physiopathology , Fluid Therapy , Heart Transplantation/adverse effects , Saline Solution, Hypertonic/administration & dosage , Vasodilation , Ventricular Dysfunction, Left/prevention & control , Ventricular Function, Left , Allografts , Animals , Cardiopulmonary Bypass/adverse effects , Disease Models, Animal , Female , Infusions, Intravenous , Interleukin-2/metabolism , Interleukin-6/metabolism , Lung/metabolism , Lung/pathology , Lung Injury/etiology , Lung Injury/metabolism , Lung Injury/pathology , Lung Injury/prevention & control , Sus scrofa , Tumor Necrosis Factor-alpha/metabolism , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology
16.
J Med Syst ; 42(2): 25, 2017 Dec 23.
Article in English | MEDLINE | ID: mdl-29273867

ABSTRACT

Ex vivo heart perfusion has been shown to be an effective means of facilitating the resuscitation and assessment of donor hearts for cardiac transplantation. Over the last ten years however, only a few ex vivo perfusion systems have been developed for this application. While results have been promising, a system capable of facilitating multiple perfusion strategies on the same platform has not yet been realized. In this paper, the design, development and testing of a novel and modular ex vivo perfusion system is described. The system is capable of operating in three unique primary modes: the traditional Langendorff Mode, Pump-Supported Working-Mode, and Passive Afterload Working-Mode. In each mode, physiological hemodynamic parameters can be produced by managing perfusion settings. To evaluate heart viability, six experiments were conducted using porcine hearts and measuring several parameters including: pH, aortic pressure, lactate metabolism, coronary vascular resistance (CVR), and myocardial oxygen consumption. Pressure-volume relationship measurements were used to assess left ventricular contractility in each Working Mode. Hemodynamic and metabolic conditions remained stable and consistent across 4 h of ex vivo heart perfusion on the ex vivo perfusion system, validating the system as a viable platform for future development of novel preservation and assessment strategies.


Subject(s)
Equipment Design , Heart/physiology , Perfusion/methods , Animals , Heart Transplantation/methods , Hemodynamics , Hydrogen-Ion Concentration , Lactic Acid/metabolism , Oxygen Consumption , Swine
17.
Can J Surg ; 60(4): 253-259, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28562236

ABSTRACT

BACKGROUND: As support times for left ventricular assist devices (LVADs) become longer, several complications requiring device exchange may occur. To our knowledge, this is the first Canadian report regarding implantable LVAD exchange. METHODS: We retrospectively reviewed the cases of consecutive, unique patients implanted with an LVAD between June 2006 and October 2015 at Toronto General Hospital. RESULTS: In total, 122 patients were impanted with an LVAD during the study period. Eight patients required LVAD exchange, and 1 patient had 2 replacements (9 of 122, 7.3%). There were 7 HeartMate II (HMII), 1 HVAD and 1 DuraHeart pumps exchanged. Two of these exchanges occurred early at the time of initial implant, whereas 7 occurred late (range 8-623 d). Six exchanges were made owing to pump thrombosis. Of the 3 exchanges made for other causes, 1 HMII exchange was owing to a driveline fracture, 1 DuraHeart patient had early inflow obstruction requiring exchange to HMII at the initial implant, and the third had a suspected inflow obstruction with no evidence of thrombosis at the time of the procedure. The mean support time before exchange was 225 days, and time from exchange to transplant, death or ongoing support was 245 days. Three patients were successfully bridged to transplant, and at the time of data collection 2 were supported awaiting transplant. Three patients died after a mean duration of 394.3 days (range 78-673 d) of support postreplacement. Four cases were successfully performed using a subcostal approach. CONCLUSION: Pump thrombosis is the most common cause for LVAD exchange, which can be performed with acceptable morbidity and mortality. The subcostal approach may be the preferred procedure for an HMII exchange when indicated.


CONTEXTE: À mesure que la durée d'utilisation des dispositifs d'assistance ventriculaire gauche (DAVG) augmente, plusieurs complications nécessitant un remplacement du dispositif peuvent survenir. À notre connaissance, il s'agit du premier rapport canadien concernant le remplacement des DAVG implantables. MÉTHODES: Nous avons passé en revue de manière rétrospective les cas individuels consécutifs de patients à qui on a implanté un DAVG entre juin 2006 et octobre 2015 à l'Hôpital Général de Toronto. RÉSULTATS: En tout, 122 patients ont reçu un DAVG pendant la période de l'étude. Huit patients ont eu besoin d'un remplacement de DAVG et 1 patient a eu besoin de 2 remplacements (9 sur 122, 7,3 %). Sept dispositifs HeartMate II (HMII), 1 dispositif HVAD et 1 dispositif DuraHeart ont été remplacés. Deux de ces remplacements sont survenus peu de temps après la pose initiale du dispositif, tandis que les 7 autres se sont produits plus tardivement (dans les 8 à 623 jours suivants). Six remplacements ont été effectués en raison d'une thrombose de la pompe. Parmi les 3 remplacements effectués pour d'autres raisons, 1 dispositif HMII a été remplacé en raison d'un bris de la ligne d'activation, 1 dispositif DuraHeart a présenté une obstruction précoce du flux entrant nécessitant la pose d'un HMII dès l'implantation initiale, et le troisième présentait une obstruction présumée du flux entrant sans signe de thrombose au moment de l'intervention. La durée moyenne d'utilisation avant le remplacement du dispositif a été de 225 jours, et l'intervalle entre le remplacement et la transplantation, le décès ou la décision de maintenir l'assistance a été de 245 jours. L'appareil a permis une transition réussie jusqu'à la transplantation chez 3 patients, et au moment de la collecte des données, 2 patients porteurs d'un DAVG étaient en attente d'une transplantation. Trois patients sont décédés après une durée moyenne de 394,3 jours (entre 78 et 673 jours) d'assistance post-remplacement. Quatre remplacements ont été effectués avec succès par une approche sous-costale. CONCLUSION: La thrombose de la pompe est la cause la plus fréquente de remplacement d'un DAVG; le remplacement peut être effectué avec des taux de morbidité et de mortalité acceptables. L'approche sous-costale serait à privilégier lorsqu'un remplacement de HMII est indiqué.


Subject(s)
Equipment Failure/statistics & numerical data , Heart-Assist Devices/adverse effects , Heart-Assist Devices/statistics & numerical data , Hospitals, General/statistics & numerical data , Outcome Assessment, Health Care/statistics & numerical data , Postoperative Complications , Reoperation/statistics & numerical data , Humans , Ontario , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/surgery , Retrospective Studies , Thrombosis/etiology , Time Factors
18.
J Thorac Cardiovasc Surg ; 150(1): 118-24.e2, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25896462

ABSTRACT

OBJECTIVES: A hemiarch reconstruction, using deep hypothermic circulatory arrest, is the conventional approach for proximal aortic arch reconstruction, but it carries risks of neurologic events and coagulopathy. The addition of a hemiarch reconstruction to an aortic root replacement may prevent future aortic arch pathology. Outcomes of this approach at a tertiary care institution were examined to determine whether the addition of a hemiarch reconstruction to an aortic root replacement conferred any additional risk. METHODS: A total of 384 patients underwent an aortic root replacement between April 2004 and June 2012. Of them, 177 (46%) had hemiarch replacement. Propensity score matching yielded 133 pairs of patients receiving hemiarch and non-hemiarch. RESULTS: Sinus segment diameter was similar between groups; ascending aortic diameter was greater in the hemiarch group (median 50 vs 44 mm; P < .001). The hemiarch group had longer perfusion (median 186 vs 120.5 minutes; P < .001) and crossclamp times (median 140 vs 104 minutes; P < .001); median circulatory arrest was 13 minutes. There was no difference, hemiarch versus no hemiarch, in 30-day mortality (3.0% vs 1.5%; P = .41), stroke (2.3% vs 4.5%; P = .31), reoperation for bleeding (11% vs 10%; P = .84), or overall survival (5-year 88.0% [95% confidence interval, 81.9-94.0] vs 91.4% [95% confidence interval, 85.8-96.9], P = .24). CONCLUSIONS: In this series, aortic root replacement ± hemiarch reconstruction had low mortality. Addition of hemiarch replacement extended perfusion times but not at the expense of safety. Hemiarch reconstruction should be performed when the aortic root aneurysm extends into the distal ascending aorta.


Subject(s)
Aorta, Thoracic/surgery , Aortic Diseases/surgery , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/methods , Combined Modality Therapy , Female , Heart Valve Prosthesis Implantation , Humans , Male , Middle Aged , Retrospective Studies , Vascular Surgical Procedures/adverse effects , Vascular Surgical Procedures/methods
19.
Eur J Cardiothorac Surg ; 43(5): 1000-5, 2013 May.
Article in English | MEDLINE | ID: mdl-22983917

ABSTRACT

OBJECTIVES: Ischaemic mitral valve regurgitation is associated with a significant reduction in survival and its treatment in patients undergoing surgical ventricular reconstruction is usually associated with higher perioperative morbidity and mortality. We evaluated our 11-year experience in this cohort of patients. METHODS: Between January 2000 and December 2010, a total of 282 patients underwent surgical ventricular reconstruction, of which 45 (16%) had concomitant mitral valve surgery. The data was retrospectively analyzed to identify variables that could predict early mortality. RESULTS: Overall in-hospital mortality was 6.4% (n = 18), of which 5.1% (n = 12) occurred in patients undergoing surgical ventricular reconstruction and 13.3% (n = 6) in patients undergoing surgical ventricular reconstruction + mitral valve surgery (P = 0.05). Patients undergoing surgical ventricular reconstruction + mitral valve surgery had poorer LV function (P < 0.01) and advanced NYHA class IV symptoms (P = 0.02) compared with patients undergoing surgical ventricular reconstruction. These patients had a higher requirement for postoperative inotropic (P < 0.01) and IABP support (P < 0.01) and were more likely to suffer from low cardiac output syndrome (P < 0.01). In patients undergoing surgical ventricular reconstruction + mitral valve surgery, 34 patients had mitral valve repair and 11 patients had mitral valve replacement. The mortality was 17.6% (n = 6) vs 0% (P = 0.31) in the mitral valve repair vs mitral valve replacement groups, respectively. The cohort of patients undergoing surgical ventricular reconstruction + mitral valve repair had poorer LV function and more advanced symptoms. CONCLUSIONS: Patients undergoing surgical ventricular reconstruction have excellent early outcomes. However, there are patients that are at an increased operative risk, such as those with concomitant ischaemic mitral regurgitation that might be better served with other surgical modalities, such as ventricular assist device or heart transplantation. The suggested algorithm based on current evidence provides a stepwise approach when dealing with patients with ischaemic mitral regurgitation ± left ventricular remodelling.


Subject(s)
Cardiac Surgical Procedures/methods , Cardiomyopathies/surgery , Mitral Valve/surgery , Myocardial Ischemia/surgery , Plastic Surgery Procedures/methods , Aged , Analysis of Variance , Cardiomyopathies/pathology , Chi-Square Distribution , Cohort Studies , Female , Humans , Male , Middle Aged , Mitral Valve/pathology , Mitral Valve Insufficiency/pathology , Mitral Valve Insufficiency/surgery , Myocardial Ischemia/pathology , Randomized Controlled Trials as Topic , Statistics, Nonparametric
20.
Circulation ; 124(11 Suppl): S197-203, 2011 Sep 13.
Article in English | MEDLINE | ID: mdl-21911813

ABSTRACT

BACKGROUND: We investigated the effect of epidermal growth factor-like domain 7 (Egfl7) on nuclear factor-κB activation, intercellular adhesion molecule-1 expression, and neutrophil adhesion to human coronary artery endothelial cells after calcineurin-inhibition-induced injury. METHODS AND RESULTS: Human coronary endothelial cells were incubated with cyclosporine (CyA) 10 µg/mL with or without Egfl7 (100 ng/mL) or the Notch receptor activator Jagged1 (200 ng/mL) for 6 to 48 hours. CyA upregulated nuclear factor-κB (p65) activity (128 ± 2% of control, P<0.001) in nuclear extracts, as determined with a DNA-binding activity ELISA. This activity was inhibited by Egfl7 (86 ± 3% of control; P<0.001 versus CyA alone). Jagged1 blocked Egfl7-induced nuclear factor-κB inhibition (105 ± 4% of control; P<0.05 versus CyA plus Egfl7). CyA upregulated cell-surface intercellular adhesion molecule-1 expression (215 ± 13% of control; P<0.001), as determined by flow cytometry. This expression was suppressed by Egfl7 (148 ± 5%; P<0.001 versus CyA alone). Jagged1 attenuated the intercellular adhesion molecule-1-suppressive effect of Egfl7 when administered with CyA (193 ± 3% versus 148 ± 5%; P<0.01). CyA increased neutrophil adhesion to human coronary endothelial cells (control 20 ± 5%, CyA 37 ± 3%; P<0.001 versus control) in a nonstatic neutrophil adhesion assay. This increase was attenuated by Egfl7 (22 ± 6%; P<0.001 versus CyA alone). Jagged 1 attenuated the effect of Egfl7 on neutrophil adhesion (31±3%; P<0.001 versus Egfl7 plus CyA). CONCLUSIONS: Our study reveals that Egfl7 is a potent inhibitor of neutrophil adhesion to human coronary endothelial cells subsequent to calcineurin-inhibition-induced injury. Mechanistically, Egfl7 blocked nuclear factor-κB pathway activation and intercellular adhesion molecule-1 expression, which suggests that it may have significant antiinflammatory properties. Because Jagged1 blocked the effect of Egfl7, Notch receptor antagonism may contribute to the mechanism of action of Egfl7.


Subject(s)
Calcineurin Inhibitors , Coronary Vessels/cytology , Endothelial Growth Factors/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Neutrophils/cytology , Neutrophils/drug effects , Calcineurin/drug effects , Calcium-Binding Proteins/pharmacology , Cell Adhesion/drug effects , Cells, Cultured , Cyclosporine/pharmacology , EGF Family of Proteins , Endothelium, Vascular/metabolism , Humans , Immunosuppressive Agents/pharmacology , Intercellular Adhesion Molecule-1/metabolism , Intercellular Signaling Peptides and Proteins/pharmacology , Jagged-1 Protein , Membrane Proteins/pharmacology , NF-kappa B/metabolism , Nitric Oxide/metabolism , Receptors, Notch/agonists , Serrate-Jagged Proteins , Signal Transduction/drug effects , Signal Transduction/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...