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Constantine Mavroudis

Publications and source records attributed to Constantine Mavroudis.

54 records · Page 3Linked to original sources
PubMed2003

Physiologic versus anatomic repair of congenitally corrected transposition of the great arteries.

When biventricular repair of congenitally corrected transposition of the great arteries (ccTGA) is possible, complete anatomic (left ventricle to the aorta, right ventricle to the pulmonary artery, and associated atrial baffle operation) or physiologic (left ventricle to pulmonary artery, right ventricle to aorta) connections are complex and associated with significant long-term problems such as arrhythmias, subaortic obstruction, valvar dysfunction, ventricular-to-pulmonary artery conduit changes, and deteriorating ventricular function. Recent advances have supported physiologic, anatomic, and single-ventricle repairs. The purpose of this article is to review the natural history of ccTGA, compare and contrast the physiologic and anatomic repairs, and reintroduce a new concept of physiologic repair for patients with ccTGA, ventricular septal defect, and pulmonary stenosis using left ventricular unloading techniques via a bidirectional shunt.

Adaptation, Physiological↗
PubMed2003

Arrhythmia surgery in association with complex congenital heart repairs excluding patients with fontan conversion.

Surgical arrhythmia therapy may be performed for patients failing the catheter ablation approach or incorporated into repair of complex congenital heart disease. Variations in atrial and ventricular anatomy that may limit the catheter approach can be directly addressed surgically assuring lesion depth and continuity of anatomic lines of block. Between July 1992 and August 2002, we performed arrhythmia surgery on 34 patients for refractory atrial (n = 29) or ventricular (n = 5) arrhythmias. Not included in this series are patients who had arrhythmia surgery during Fontan conversion. The majority of patients had various forms of complex congenital heart disease; two had structurally normal hearts. Median age at surgery was 13.0 years (range, 7 days to 45 years). Five patients were infants (mean age, 25 days). Twenty-two patients (65%) had an average of 2.8 previous cardiac procedures; all required resternotomy. Operative mortality was 5.9% (2 of 34 patients) because of low cardiac output in one patient following Mustard takedown and arterial switch operation and in one neonate with Ebstein's anomaly and pulmonary atresia. Ablative surgery for supraventricular tachycardia (atrial re-entry, automatic atrial, atrioventricular nodal re-entry, and atrial fibrillation) had a 93% success rate (25 of 27 patients). Clinical tachycardia recurred in two of 27 surviving patients (7%) with atrial arrhythmia, one after an arrhythmia-free interval of several years. Ventricular tachycardia was inducible postoperatively in two of three patients with ventricular arrhythmias and congenital heart disease. Patient size or anatomic complexity should not be limiting factors in the combined surgical arrhythmia approach. Because older patients undergoing surgical revision of prior surgical repairs of congenital heart disease are at increased risk for the later development of atrial arrhythmias, incorporation of arrhythmia therapy into any planned surgical revision should be routinely considered.

Arrhythmias, Cardiac↗
PubMed2003

Dexamethasone reduces postoperative troponin levels in children undergoing cardiopulmonary bypass.

OBJECTIVE: We previously demonstrated that dexamethasone treatment before cardiopulmonary bypass in children reduces the postoperative systemic inflammatory response. The purpose of this study was to test the hypothesis that dexamethasone administration before cardiopulmonary bypass in children correlates with a lesser degree of myocardial injury as measured by a decrease in cardiac troponin I release. DESIGN: A prospective, randomized, double-blind study. SETTING: The cardiac surgery operating room and intensive care unit of a pediatric referral hospital. SUBJECTS: Twenty-eight patients who underwent open-heart surgery for congenital heart defects. INTERVENTIONS: Patients received either placebo (group I, n = 13) or dexamethasone, 1 mg/kg iv (group II, n = 15), 1 hr before initiation of cardiopulmonary bypass. Plasma cardiac troponin I samples were obtained at three time points: immediately before study agent (sample 1), 10 mins after protamine sulfate administration after cardiopulmonary bypass (sample 2), and 24 hrs postoperatively (sample 3). MEASUREMENTS AND MAIN RESULTS: Mean cardiac troponin I levels (+/-sd) were significantly lower at sample time 3 in group II (dexamethasone; 33.4 +/- 20.0 ng/mL) vs. group I (control; 86.9 +/- 81.1) (p =.04). CONCLUSION: Dexamethasone administration before cardiopulmonary bypass in children resulted in a significant decrease in cardiac troponin I levels at 24 hrs postoperatively. We postulate that this may represent a decrease in myocardial injury, and, thus, a possible cardioprotective effect produced by dexamethasone.

Analysis of Variance↗
PubMed2002

Comparison of anatomic isthmus block with the modified right atrial maze procedure for late atrial tachycardia in Fontan patients.

BACKGROUND: Late atrial reentry tachycardia (AT) after Fontan repair is common, with limited efficacy of medical therapy in preventing AT recurrence. In this study, two approaches to surgical arrhythmia ablation in patients with refractory AT undergoing Fontan revision are compared: cryoablation of the inferomedial right atrium (RA), and a more extensive modified RA maze procedure designed to eliminate all potential RA reentrant circuits. METHODS AND RESULTS: Fontan revision was performed in 23 patients with AT, using inferomedial RA cryoablation (Group 1, n=8) and modified RA maze procedure (Group 2, n=15). There was no difference in age at initial Fontan, age at Fontan revision, age at onset of AT, or number of failed antiarrhythmic medications. Patients underwent preoperative, intraoperative, and postoperative electrophysiological studies. Thirty-eight different tachycardia circuits were induced in preoperative studies with 3 major areas of RA involvement: the lower lateral RA, the atrial septum, and the inferomedial RA. At postoperative electrophysiological study, AT was inducible in 62% of Group 1 patients but only 7% of Group 2 patients (P<0.02). With mean follow-up of 43 months, 5 of 8 patients in Group 1 experienced AT recurrence compared with none in Group 2 (P<0.001). There was no significant difference in length of hospital stay or complication rate comparing the two groups. CONCLUSION: Modified RA maze procedure is superior to anatomic isthmus block in treating reentrant AT in postoperative Fontan patients. The modified RA maze has eliminated AT recurrence at mid-term follow-up with low morbidity and mortality.

Adolescent↗
PubMed2002

Serum vascular endothelial growth factor as a surveillance marker for cellular rejection in pediatric cardiac transplantation.

BACKGROUND: Early detection and treatment of acute rejection in cardiac transplant recipients significantly improves long-term survival. Endomyocardial biopsy is used routinely for diagnosing allograft rejection; however, in young children, this procedure carries some risk. We evaluated serum vascular endothelial growth factor (VEGF) as a potential surveillance marker of acute cellular rejection. METHODS: Blood samples (n=62) were analyzed from 23 patients and compared with controls (n=18) using an ELISA for VEGF. Results were correlated with endomyocardial biopsy rejection grades. RESULTS: Mean baseline VEGF levels of the transplant population were consistently higher than controls. Serum VEGF levels were significantly higher during acute cellular rejection when compared with the non-rejecting transplant group (700.7+/-154 pg/ml vs. 190.5+/-29 pg/ml). VEGF decreased two- to eightfold after immunosuppressive therapy in 9 of 11 rejection episodes. CONCLUSIONS: These data suggest that VEGF may play a role in the pathogenesis of acute allograft rejection and it may serve as a reliable serologic surveillance marker.

Acute Disease↗
PubMed2002

Congenital heart surgery nomenclature and database project. Update and proposed data harvest.

In 1998, the first report of the Society of Thoracic Surgery (STS) National Congenital Heart Surgery Database defined clinical features for 18 congenital heart disease categories, providing a significant amount of important information and pinpointing database strengths and weaknesses. Following this report, the STS Congenital Heart Surgery Committee, working with the European Association of Cardio-Thoracic Surgery and the European Congenital Heart Surgeons Foundation, initiated the International Congenital Heart Surgery and Nomenclature Database Project. To standardize nomenclature and reporting strategies and establish a foundation for an international congenital heart surgery database. The project's first report was published in the Annals of Thoracic Surgery in April 2000. The current report outlines modifications to the minimal dataset and diagnosis and procedure short lists.

Databases, Factual↗
PubMed2002

Congenital Heart Surgery Nomenclature and Database Project: update and proposed data harvest.

The first report of The Society of Thoracic Surgeons (STS) National Congenital Heart Surgery Database in 1998 reported the clinical features of 18 congenital heart categories. The report provided a significant amount of important information and also highlighted the strengths and weaknesses of the existing database. Following this report the STS Congenital Heart Surgery Committee in cooperation with the European Association of Cardio-Thoracic Surgery and the European Congenital Heart Surgeons Foundation initiated the International Congenital Heart Surgery Nomenclature and Database Project. The goal was to begin the standardization of nomenclature reporting strategies and establish the foundations for an international congenital heart surgery database. The first report of the International Congenital Heart Surgery Nomenclature Project was published in The Annals of Thoracic Surgery in April 2000. The current report outlines modifications to the minimum dataset as well as the diagnoses and procedure short lists. Plans for the next STS National Congenital Heart Surgery Database harvest are also presented.

Cardiac Surgical Procedures↗
PubMed2002

Anomalous origin of the left coronary artery from the pulmonary artery: collective review of surgical therapy.

Anomalous origin of the left coronary artery from the pulmonary artery is an extremely rare but potentially fatal congenital coronary anomaly. Prompt surgical reestablishment of a two-coronary system on diagnosis yields excellent results and allows progressive and nearly total myocardial recovery. Follow-up of all patients is required to assess the adequacy of repair and to exclude ongoing or recurrent myocardial insult.

Coronary Vessel Anomalies↗
PubMed2002

Congenital Heart Surgery Nomenclature and Database Project: update and proposed data harvest.

In 1998, the first report of the Society of Thoracic Surgery (STS) National Congenital Heart Surgery Database reported the clinical features of 18 congenital heart categories. The report provided a significant amount of important information and also highlighted the strengths and weaknesses of the existing database. Following this report, the STS Congenital Heart Surgery Committee, in cooperation with the European Association of Cardio-Thoracic Surgery and the European Congenital Heart Surgeons Foundation, initiated the International Congenital Heart Surgery and Nomenclature Database Project. The goal was to begin the standardization of nomenclature and reporting strategies and establish the foundations for an international congenital heart surgery database. The first report of the International Congenital Heart Surgery Nomenclature Project was published in the Annals of Thoracic Surgery in April 2000. The current report outlines modifications to the minimal dataset, as well as the diagnosis and procedure short lists.

Cardiac Surgical Procedures↗
PubMed2002

Repair of congenital tracheal stenosis.

We have used six different techniques in 61 operations performed at Children's Memorial Hospital (Chicago, IL) between 1982 and 2001 on 54 infants with complete tracheal rings and primary or recurrent tracheal stenosis. Short-term and long-term outcomes are reviewed for all techniques including pericardial tracheoplasty, tracheal autograft, tracheal resection, cartilage tracheoplasty, slide tracheoplasty, and aortic homograft patch tracheoplasty. Patients' ages ranged from 7 days to 72 months; mean age at operation was 6 months. There were 33 boys and 21 girls. Associated pulmonary artery sling was present in 19 of 54 patients (35%). Significant associated intracardiac anomaly was present in 13 of 54 patients (24%). The number of complete tracheal rings involved ranged from two to 18 rings (mean, 14+/-5). All procedures were performed with the use of cardiopulmonary bypass. Simultaneous repair of pulmonary artery sling and cardiac abnormalities was undertaken. There were three early deaths, two after pericardial tracheoplasty and one after tracheal autograft. There were eight late deaths, five after pericardial tracheoplasty, one after tracheal autograft, one after slide tracheoplasty, and one after tracheal resection. Median length of hospital stay was 60 days for pericardial tracheoplasty, 28 days for tracheal autograft, 14 days for tracheal resection, and 18 days for the slide tracheoplasty. Follow-up is complete in all patients. Tracheal autograft is currently our procedure of choice for patients with long-segment tracheal stenosis because of its use of all-autologous material, technical ease of performance, already-present epithelial lining of the autograft, intrinsic maintenance of the cartilage contour, potential for growth, and ready availability. We limit the use of tracheal resections to patients with eight or less rings of tracheal stenosis.

Cardiopulmonary Bypass↗
PubMed2002

The beneficial effects of total cavopulmonary conversion and arrhythmia surgery for the failed Fontan.

Postoperative Fontan patients can develop hemodynamic abnormalities and refractory atrial arrhythmias resulting in significant morbidity and mortality. We present our experience with total cavopulmonary artery conversion and arrhythmia surgery. Between 1994 and 2001, 41 patients underwent total cavopulmonary artery conversion and arrhythmia surgery. Significant hemodynamic lesions were repaired concomitantly: aortic aneurysm (n=1), atrioventricular valve insufficiency (n=8), and pulmonary artery stenosis (n=9). Thirty-five patients were in New York Heart Association class III or IV. Mean age at original Fontan was 7.5+/-6.5 years, at Fontan conversion, 18.7+/-9.0 years. Arrhythmia surgery for atrial re-entry tachycardia evolved from isthmus cryoablation (n=10) to right-sided maze (n=17). Maze-Cox III was used for 14 patients with atrial fibrillation. Atrial (n=34) and dual chamber (n=5) pacemakers were placed. Mortality and reoperation for bleeding rates are 0%. Chest tubes were removed on postoperative day 9.0+/-6.0. Mean hospital stay was 11.8+/-6.6 days. Three patients required cardiac transplantation at 8 days, 9 months, and 33 months postoperatively. There was one long-term death from acute myocardial infarction 2 years postoperatively. For the entire series, arrhythmia recurrence is 12.2% (5/41). Only 9.8% of patients (4/41) receive chronic antiarrhythmic medications; these patients were among the first eight in the series. Most patients are in New York Heart Association I or II. Bruce protocol in 12 patients showed increased tolerance (P<.05) Total cavopulmonary artery conversion with concomitant arrhythmia surgery is excellent therapy for patients with failed Fontan. It is safe, improves New York Heart Association class, improves exercise tolerance, and the incidence of recurrent arrhythmias is low.

Adolescent↗
PubMed2002

Virtues of a worldwide congenital heart surgery database.

The rationale for a congenital heart surgery database lies in the organized manner in which information can be compiled to accomplish programmatic evaluation, monitor clinical outcomes, comply with governmental requirements, perform retrospective and prospective clinical studies, and participate in local, national, and global improvement strategies. The task of inaugurating an effective congenital heart surgery database has taken many years and involved concurrent development efforts at multiple sites. Two such efforts took place in North America with the Society of Thoracic Surgeons Congenital Heart Surgery Database, and in Europe with the European Congenital Heart Defects Database. These initial efforts provided the impetus for development of an international congenital heart surgery database that would allow scientific exchanges on an international scale and promote multi-institutional evaluation of congenital heart surgery. Sample outcome templates from the Society of Thoracic Surgeons and the European Association for Cardio-thoracic Surgery's accepted minimum database data set are reviewed for the specific diagnostic entry ventricular septal defect, to familiarize the reader with potential available data summaries and outcome analyses, including risk stratification, when data harvest is performed. In Europe, the agreed upon minimum data set are now collected as part of the Pediatric European Cardiac Surgical Registry, while in North America users of the CardioAccess database and users of the minimum data set downloaded from the Society of Thoracic Surgeons web site are being notified of plans for a 2002 data harvest incorporating the minimum database data set. It is likely that the extant voluntary, minimal data set congenital heart surgery database will be replaced by a mandated system required by states, provinces, and countries. Data collection schemes and data validation programs will become standardized, which will result in improved data quality and uniform congenital heart center participation. As participation with valid data approaches 100% of congenital heart centers, the power and importance of the database increases exponentially. Reliable information can be used to assess residency/fellowship programs, resource allocation, major therapeutic trends, manpower issues, and in the end, all initiatives that will require accurate information.

Databases, Factual↗
PubMed2000

Anomalous origin of the left coronary artery from the pulmonary artery: Successful surgical strategy without assist devices.

The objective of this review was to analyze a surgical strategy for children with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) where aortic implantation was successful without the use of extracorporeal membrane oxygenation (ECMO) or left ventricular assist device (LVAD). From 1989 through 1999, 16 consecutive children underwent aortic implantation for ALCAPA. Median age was 0.45 years. Surgical strategy included bicaval venous cannulation, LV vent, moderate systemic hypothermia (28 degrees C), antegrade cardioplegia with pulmonary artery (PA) occlusion, PA transection, aortic implantation with a large "button" of PA, PA reconstruction with pericardium, intraoperative transesophageal echocardiography, and inotropic support with dopamine, dobutamine, and milrinone. All patients survived. No patient was placed on ECMO or LVAD. Mean cardiopulmonary bypass (CPB) time was 152 +/- 41 minutes. Mean aortic cross-clamp time was 46 +/- 13 minutes. Mean time from cross-clamp removal to CPB off ("weaning" time) was 58 +/- 20 minutes. One patient had delayed sternal closure. Only 2 patients required more than 10 &mgr;g/kg/minute of dopamine and dobutamine. Mean hospital stay was 29 +/- 25 days. One patient required outpatient inotropic support for 5 months. Although ECMO or LVAD may be necessary for some ALCAPA patients, we describe a surgical strategy of aortic implantation that was successful without the use of assist devices. Copyright 2000 by W.B. Saunders Company

Journal Article↗
PubMed1999

The favorable impact of arrhythmia surgery on total cavopulmonary artery Fontan conversion.

Patients who have undergone atriopulmonary Fontan procedures are at risk for significant atrial arrhythmias and obstructive connections, which have been related to intra-atrial suture lines, atrial enlargement, and somatic growth. Twenty patients (mean age, 17.3 +/- 6.8 years) had conversion to total cavopulmonary artery connection 8.9 +/- 2.1 years after the previous Fontan procedure (for atrial arrhythmias in 19 patients and for obstructive lesions in one). Arrhythmia ablative surgery evolved over the study period from "arrhythmia circuit cryoablation" (cryoablation lesions completing lines of block) to the more standard approaches of modified right-sided Maze and Maze-Cox III procedures. Preoperative functional New York Heart Association class was IV in nine patients, III in nine, and II in two. All patients survived. Two patients had prolonged chest drainage (there was pericardial effusion in one). The average length of hospital stay was 11.3 +/- 5.4 days; chest tubes were removed on day 8.5 +/- 5.4. There were no long-term deaths (mean follow-up period, 20.3 +/- 14.9 months; range, 2 months to 4 years). Late postoperative arrhythmias occurred in two patients who are receiving long-term antiarrhythmic medications. All patients have improved to New York Heart Association class I or II. Total cavopulmonary artery Fontan conversion in association with modified right-sided Maze or Maze-Cox III procedures and pacemaker placement can be accomplished with low morbidity and mortality, and results in functional class improvement and control of life-threatening arrhythmias. Copyright 1999 by W.B. Saunders Company

Journal Article↗
PubMedDate not supplied

Platelet and leukocyte activation and design consequences for thoracic artificial lungs.

Blood contact with the prosthetic surfaces of artificial lungs causes extensive activation of molecular and cellular mediators of coagulation and inflammation that can lead to patient morbidity and mortality. To determine the effects of artificial lung fiber bundle shear stress and surface area on blood activation, porcine blood was recirculated for 4 hours through circuits containing mock artificial lungs with bundle shear stresses of 11.6, 7.3, and 3.9 dynes/cm2 and surface areas of 5.2, 3.5, and 1.7 cm2/ml of circuit volume. Blood from these circuits was assayed for platelet and leukocyte counts, soluble P-selectin concentrations, and lactoferrin concentrations to determine the level of platelet and leukocyte adherence to the circuit, platelet activation, and leukocyte activation, respectively. Neither platelet nor leukocyte counts were significantly affected by shear stress or surface area. P-selectin and lactoferrin concentrations were significantly greater at a fiber bundle shear stress of 11.6 dynes/ cm2. P-selectin and lactoferrin concentrations were significantly greater at a fiber bundle surface area of 5.2 cm2/ml of circuit volume. Artificial lungs, therefore, should be designed with average bundle shear stresses < 11.6 dynes/cm2 and with surface areas < 5.2 cm2/ml of circuit volume. Current thoracic artificial lungs meet both these requirements.

Animals↗
PubMedDate not supplied

Hemodynamic and gas transfer properties of a compliant thoracic artificial lung.

A compliant thoracic artificial lung (TAL) has been developed for acute respiratory failure or as a bridge to transplantation. The development goal was to increase TAL compliance, lower TAL impedance, and improve right ventricular function during use. Prototypes were tested in vitro and in vivo in eight pigs between 67 and 79 kg to determine hemodynamic and gas transfer properties. The in vitro compliance was 16.2 +/- 4.4 ml/mm Hg at pressures < 7.8 mm Hg and 4.3 +/- 1.1 ml/mm Hg above 7.8 mm Hg. In vivo, this compliance significantly reduced blood flow pulsatility from 1.7 at the inlet to 0.36 at the outlet. Device resistance was 1.9 and 1.8 mm Hg/(L/min) at a flow rate of 4 L/min in vitro and in vivo, respectively. Approximately 75% of the resistance was at the inlet and outlet. In vivo TAL O2 and CO2 transfer rates were 188 and 186 ml/min, respectively, at 4 L/min of blood and gas flow, and average outlet O2 saturations exceeded 98% for average flow rates up to and including the maximum tested, 5.3 L/min. The new design has a markedly improved compliance and excellent gas transfer but also possesses inlet and outlet resistances that must be reduced in future designs.

Animals↗
PubMedDate not supplied

Inhaled prostacyclin following surgical repair of congenital heart disease--a pilot study.

BACKGROUND: The development of additional therapies for the treatment of pulmonary hypertension would be a significant advancement in the treatment of congenital heart disease. Recently, studies have found inhaled prostacyclin (PGI2) is an effective pulmonary vasodilator, comparable with nitric oxide. In this prospective interventional pilot study, we examined the physiologic effects of inhaled PGI2 in children with congenital heart disease and pulmonary hypertension. METHODS: Six children (median age 6 months, range 5 to 21 months) with congenital heart disease and preoperative pulmonary hypertension (mean pulmonary artery pressure [MPAP] greater than 50% systemic) received a 15-minute course of inhaled PGI2 intraoperatively postrepair. The inhaled PGI2 was delivered by aerosolizing the IV formulation (Flolan, Glaxo-Wellcome) to achieve a dose of 50 ng/kg/min. Physiologic parameters measured during the medication period were compared with measurements taken during two 15-minute baseline periods before and after the medication period. RESULTS: Inhaled PGI2 significantly reduced the mean pulmonary artery pressure from 25 +/- 3 to 21 +/- 3 (p < 0.01) and improved the PaO2/FiO2 ratio from 275 +/- 181 to 433 +/- 285 (p = 0.01). There were no significant changes in systemic blood pressure, heart rate, or cardiac index. CONCLUSIONS: Children with congenital heart disease and pulmonary hypertension may benefit from inhaled PGI2. Inhaled PGI2 reduced pulmonary blood pressures and improved oxygenation in this small study. PGI2 acts through cyclic adenosine monophosphate mediated pulmonary vasodilation, a mechanism different from nitric oxide. In children with inadequate response to nitric oxide, inhaled PGI2 may be a useful alternative pulmonary vasodilator.

Administration, Inhalation↗