Repair of left ventricular aneurysm with acellular dermis graft: A case report.

We report the use of a novel graft material in cardiac surgery, acellular human dermis graft, to repair a left ventricular aneurysm in a patient undergoing surgical ventricular restoration. We also describe the postoperative magnetic resonance imaging characteristics of the dermis graft. We conclude that acellular dermis graft has material handling properties that allow it to be used in left ventricular aneurysm repair.

Pericardial hemangioma taking origin from the posterior wall of the left atrium.

We present a rare case of a pericardial hemangioma taking origin from the posterior wall of the left atrium and compressing the surrounding structures. Contrast cardiac magnetic resonance imaging preoperatively established the diagnosis, and computed tomographic findings helped in the management of this patient.

Effects of stretch or distention on phenylephrine-induced constriction of human coronary artery bypass grafts.

Objective: To determine the effects of grafting saphenous veins into the arterial circulation and to compare the responsiveness of saphenous veins and mammary arteries to vasoconstrictors (phenylephrine or potassium) and a vasodilator (the calcium antagonist isradipine).

Design: Prospective, controlled, in vitro study.

Setting: Laboratory facility in a university teaching hospital.

Early fungal endocarditis in homograft recipients.

Retrospective analysis of 200 homograft valve recipients at our institution revealed two cases of fungal endocarditis. Pathogenesis appears to be related to either recipient seeding in one elderly immunocompromised patient or a previously contaminated donor valve implanted in an otherwise healthy recipient. Therefore, our experience underscores the need for both meticulous prevention of fungal infection preoperatively in the recipient and elimination of previously contaminated homograft valves from the donor pool.

Prediction of Homograft Aortic Valve Size by Transthoracic and Transesophageal Two-Dimensional Echocardiography.

To avoid the problem of patient valve mismatch we assessed the reliability of echocardiographic measurements in selecting an appropriate-sized homograft aortic valve. Preoperative transthoracic echocardiography (TTE) was performed in 26 consecutive patients undergoing aortic valve replacement with a cryopreserved human homograft; 19 of the patients also had intraoperative transesophageal echocardiography (TTE). The diameters of left ventricular outflow tract (LVOT), aortic annulus, sinuses of Valsalva, and ascending aorta were measured by the same technique in all patients.

Management of left ventricular assist device infection with heart transplantation.

Background: Left ventricular assist devices (LVADs) are being used as bridges to heart transplantation (HT). Infection of the LVAD in this patient population represents a serious complication, as simple LVAD removal or delaying HT may result in death. To improve outcomes in this group of patients, we performed HT in the presence of LVAD infection.

Increased activation of the coagulation and fibrinolytic systems leads to hemorrhagic complications during left ventricular assist implantation.

Background: Left ventricular assist devices (LVADs) have provided a new therapeutic option for patients with end-stage heart failure. Despite advances in device design, there remains an apparent bleeding diathesis, which leads to increased transfusion requirements and reoperative rates. The purpose of our study was to examine the abnormalities that might contribute to these clinical sequelae.

The effects of Carmeda Bioactive Surface on human blood components during simulated extracorporeal circulation.

Postoperative morbidity after cardiopulmonary bypass most commonly manifests as bleeding diatheses or pulmonary dysfunction. The pathophysiology has been attributed to the activation of cellular and humoral components of blood after contact with an artificial surface. Development of a surface that would be nonthrombogenic and also would constitute a less potent inflammatory stimulus would therefore be beneficial.

Effect of bullectomy on diaphragm strength.

Surgical removal of bullous lesions in selected patients with chronic obstructive pulmonary disease may significantly improve lung function, gas exchange, and functional status and reduce dyspnea. Proposed mechanisms by which bullectomy may produce these beneficial effects include (1) improving ventilation and perfusion matching by allowing compressed viable lung to re-expand and participate in gas exchange; (2) restoring outward elastic tension on small airways, thereby reducing airways obstruction; and (3) reducing end-expiratory lung volume, thereby diminishing the adverse effects of chronic hyperinflation on chest wall elastic recoil and inspiratory muscle force generation. In this report, we demonstrate the effect of bullectomy on transdiaphragmatic pressure generation, gas exchange, and exercise capacity in a patient with severe bullous emphysema who underwent unilateral bullectomy.

Adult orthotopic heart transplantation using undersized pediatric donor hearts. Technique and postoperative management.

Background: Because of the critical shortage of adult donor hearts, many recipients die awaiting transplantation of an organ of appropriate size. Undersized hearts (donor/recipient weight ratio < 0.7) have been used for heterotopic heart transplantation.

Iloprost reduces procoagulant activity in the extracorporeal circuit.

Although activation of formed blood elements during cardiopulmonary bypass has been examined, its presumed procoagulant role has not been identified or quantified. We evaluated the effects of iloprost, an inhibitor of platelet and leukocyte function, on subclinical coagulation during simulated extracorporeal circulation. We determined that a heparin dose of 1 U/ml prevented clot formation in this model, but resulted in elevated plasma levels of fibrinopeptide A, the first cleavage product of fibrinogen.

The effects of heparin bound surface modification (Carmeda Bioactive Surface) on human platelet alterations during simulated extracorporeal circulation.

To determine if treatment with covalently bound heparin (Carmeda Bioactive Surface (CBAS)) to the synthetic surface of the extracorporeal circuit (ECC) would alter the stereotypic pattern of adverse platelet alterations, 450 ml of heparinized blood (lU/ml) was recirculated at a flow rate of twice the circulating volume (L/min) for 2 hrs at 37 degrees C through either untreated (CONT,n=7) or treated (CBAS,n=7) circuits constructed of identical components including a pediatric (0.8m 2) reversed hollow fiber membrane oxygenator. In CONT circuits, platelet count maintained 88+1% (x+/-SEM) of its initial level in the circuit prime sample, dropped to 36+/-6% after 5 min, and returned to 56+/-2% following 2 hrs of ECC.

Cyclosporin A augments human platelet sensitivity to aggregating agents by increasing fibrinogen receptor availability.

Clinical use of cyclosporin A (CsA) has been associated with platelet hypersensitivity and an increased incidence of thrombotic and vasoactive events. The purpose of this study was (1) to confirm that CsA enhances platelet sensitivity to the soluble agonists, adenosine diphosphate (ADP) and epinephrine (EPI), and (2) to determine if this enhancement is mediated by alteration in the availability of platelet surface fibrinogen receptors, a final mediator of platelet activation. Mean log dose of ADP required to achieve complete second-wave platelet aggregation in vitro decreased from 1.

Effects of simulated extracorporeal circulation on human leukocyte elastase release, superoxide generation, and procoagulant activity.

Activated leukocytes are thought to contribute to respiratory dysfunction, alterations in microvascular permeability, disseminated intravascular coagulation, and thrombosis, all of which can complicate extracorporeal circulation. The purpose of this work was to determine the effects of extracorporeal circulation on leukocyte functions likely to mediate organ damage. White blood cell counts in the bubble circuits (n = 5) fell to 51% +/- 7% (mean +/- standard error of the mean; p less than 0.

Intraoperative management of patients with heparin-induced thrombocytopenia.

For 11 patients with confirmed heparin-induced thrombocytopenia, we used reversible platelet inhibition with iloprost, a stable prostacyclin analogue, to permit safe heparin administration for cardiac (n = 9) or vascular (n = 2) operations. In vitro, iloprost (0.01 mumol/L) prevented both heparin-induced platelet aggregation and 14C-serotonin release in all patients.

Platelet function in cardiopulmonary bypass and artificial organs.

Extensive contact between blood and synthetic surfaces is associated with both quantitative and qualitative changes in platelet function. Cardiopulmonary bypass is associated with a decline in the circulating platelet count, release of platelet alpha granules and possibly platelet dense and lysosomal granule release, and a prolongation of the bleeding time. It is assumed that these platelet alterations contribute to postoperative blood loss and reoperation for bleeding.

Cardiac ischemia and endothelial function in the isolated rabbit heart.

Truly effective prevention of reperfusion myocardial damage is precluded in part by a lack of understanding of the earliest events which accompany ischemia. The purpose of this study was to assess the coronary endothelial response to two forms of ischemic injury in an isolated crystalloid perfused rabbit heart. Global cardiac ischemia, confirmed by NADH fluorescence photography, was induced either by mechanically reducing coronary flow by 90% (MRCF, N = 11) or by an infusion of N-formyl-methionyl-leucyl-phenylalanine (fMLP, N = 11), a known stimulus for leukotriene synthesis and coronary vasospasm.

Heparin-induced platelet activation: the role of thromboxane A2 synthesis and the extent of platelet granule release in two patients.

Heparin-induced thrombosis is due to an immune-mediated activation of circulating platelets and has significant clinical implications for patients with vascular disease. The purpose of this article was (1) to define the biochemical mechanisms of heparin-induced platelet activation (HIPA) and (2) to determine the relationship between thromboxane A2 (TxA2) synthesis and platelet granule release. In two patients with confirmed HIPA, heparin (3 U/ml) induced extensive platelet aggregation (61.

Temporary inhibition of platelet function with iloprost (ZK36374) preserves canine platelets during extracorporeal membrane oxygenation.

Contact between blood and artificial surfaces results in extensive quantitative and qualitative alterations in platelet function. We evaluated the efficacy of a brief infusion of iloprost (ZK36374), a stable analog of prostacyclin, in preventing these platelet changes during extracorporeal membrane oxygenation. Twelve nonsplenectomized male mongrel dogs (23 to 30 kg) were randomized to treatment (n = 6) and control (n = 6) groups.