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Biomedical subjects

Constantine Mavroudis

Publications and source records attributed to Constantine Mavroudis.

At least 37 records · Page 2Linked to original sources
PubMed2005

Effect of cardiopulmonary bypass and surgical intervention on the natriuretic hormone system in children.

OBJECTIVES: We sought to determine the effect of cardiopulmonary bypass and surgical intervention on the natriuretic hormone system in children and to assess whether such changes are associated with morbidity. METHODS: At 6 perioperative time points in 25 patients, plasma levels of atrial natriuretic peptide, brain natriuretic peptide, and guanosine 3', 5'-monophosphate were measured, and the biologic activity of the natriuretic hormone system was quantified. Relationships were sought between changes in brain natriuretic peptide levels, biologic activity, and a number of morbidity indicators. RESULTS: There was a significant change in atrial natriuretic peptide levels (P = .037), brain natriuretic peptide levels (P = .001), and biologic activity of the natriuretic hormone system (P = .009) over the first 4 time points in the study. Atrial natriuretic peptide levels transiently decreased from baseline to 12 hours after surgical intervention. Compared with baseline values, brain natriuretic peptide levels were increased at 12 hours after surgical intervention and on postoperative day 1. The increase in brain natriuretic peptide levels from baseline to 12 hours after surgical intervention was associated with cardiopulmonary bypass time (r(s) = 0.4, P = .047). The biologic activity transiently decreased from baseline to intensive care unit admission but was not associated with any morbidity indicators. CONCLUSIONS: Increased postoperative brain natriuretic peptide levels are associated with longer bypass times. The biologic activity of the natriuretic hormone system is transiently impaired. Larger studies should investigate brain natriuretic peptide as a predictor of postoperative morbidity and the potential for natriuretic hormone infusions to improve postoperative hemodynamics and urine output.

Adolescent↗
PubMed2005

The case against minimally invasive cardiac surgery.

Stellar outcomes have been achieved for patent ductus arteriosus (PDA), atrial septal defect (ASD), and ventricular septal defect (VSD) repairs by using the traditional surgical methods. Over the last decade, minimally invasive procedures have been introduced that promise excellent results with an improved cosmetic appearance, shorter rehabilitation period, less pain, and decreased hospital cost. We reviewed various minimally invasive procedures that are used in PDA, ASD, and VSD to assess their safety and efficacy. These techniques use limited approaches to the heart (partial sternotomies, transxiphoid, anterolateral thoracotomy, and mini-thoracotomy) that reduce the surgeons access and control of the cardiac structures. Cannulation sites for the establishment of cardiopulmonary bypass have been altered. Minimally invasive therapies for congenital heart surgery cannot be adopted until evidence-based data has proven them to be equal or better than the traditional procedure.

Cardiac Surgical Procedures↗
PubMed2004

Lessons learned from the data analysis of the second harvest (1998-2001) of the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database.

OBJECTIVE: The analysis of the second harvest of the STS Congenital Heart Surgery Database produced meaningful outcome data and several critical lessons relevant to congenital heart surgery outcomes analysis worldwide. METHODS: This data harvest represents the first STS multi-institutional experience with software utilizing the nomenclature and database requirements adopted by the STS and EACTS (April 2000 Annals of Thoracic Surgery). Members of the STS Congenital Heart Committee analyzed the STS data. RESULTS: This STS harvest includes data from 16 centers (12787 cases, 2881 neonates, 4124 infants). In 2002, the EACTS reported similar outcome data utilizing the same database definitions (41 centers, 12736 cases, 2245 neonates, 4195 infants). Lessons from the analysis include: (1) Death must be clearly defined. (2) The Primary Procedure in a given operation must be documented. (3) Inclusionary and exclusionary criteria for all diagnoses and procedures must be agreed upon. (4) Missing data values remain an issue for the database. (5) Generic terms in the nomenclature lists, that is terms ending in Not Otherwise Specified (NOS), are redundant and decrease the clarity of data analysis. (6) Methodology needs to be developed and implemented to assure and verify data completeness and data accuracy. 'Operative Mortality' and 'Mortality Assigned to this Operation' were defined by the STS and EACTS; these definitions were not utilized uniformly. 'Thirty Day Mortality' was problematic because some centers did not track mortality after hospital discharge. Only 'Mortality Prior to Discharge' was consistently reported. Designation of Primary Procedure for a given operation determines its location for analysis. Until Complexity Scores lead to automated methodology for choosing the Primary Procedure, the surgeon must designate the Primary Procedure. Inclusionary and exclusionary criteria for all diagnoses and procedures have been developed in an effort to define acceptable concomitant diagnoses and procedures for each analysis. Improvements in data completeness can be achieved using a variety of techniques including developing more functional techniques of data entry at individual institutions and software improvements. Future versions of the STS Congenital Database will request that the coding of diagnoses and procedures avoid the terms ending in NOS. CONCLUSIONS: Lessons from this data harvest should improve congenital heart surgery outcome analysis.

Databases, Factual↗
PubMed2004

Captopril suppresses post-transplantation angiogenic activity in rat allograft coronary vessels.

BACKGROUND: The development of transplant coronary artery disease is associated with neovascularization in the thickened neointima. We previously reported that captopril inhibits neointimal proliferation in a rat allograft model. We postulated that angiogenic inducers are upregulated post-transplantation and captopril ameliorates transplant coronary artery disease by suppressing the angiogenic activity of coronaries. METHODS: Animals received no treatment or captopril (50 mg/kg/day). Allograft hearts were analyzed at post-transplantation Days 0, 14, and 21 and angiogenic inducer, plasma platelet-activating factor, determined. The conditioned media from coronaries and myocardium were tested for vascular endothelial growth factor, thrombospondin-1 and angiogenic activity using an endothelial migration assay and rat corneal neovascularization assay. RESULTS: The captopril-treated group had reduced plasma platelet-activating factor and coronary media revealed earlier upregulation of thrombospondin-1 secretion, diminished vascular endothelial growth factor and no angiogenic activity. At Day 0, the coronary and myocardial conditioned medium had inhibitory activity due to thrombospondin-1, and circulating levels of platelet-activating factor were negligible. By 21 days post-transplantation, plasma platelet-activating factor was elevated and the conditioned medium from untreated coronaries had significantly higher angiogenic activity due to increased vascular endothelial growth factor whereas the myocardium remained non-angiogenic. CONCLUSIONS: After transplantation, coronary vessels switch to an angiogenic phenotype and vascular endothelial growth factor contributes to the high angiogenic activity, possibly exacerbated by high circulating levels of platelet-activating factor. The ability of captopril to modulate angiogenic mediators and maintain the allograft coronary to its normal anti-angiogenic phenotype may be one mechanism by which it suppresses transplant coronary artery disease.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Surgery for arrhythmias in children.

BACKGROUND: Transcatheter radiofrequency ablation to treat supraventricular and ventricular arrhythmias has supplanted routine surgical ablative therapy and redefined its role. A small population of arrhythmia patients now requires surgical ablation: those who have failed catheter ablation, patients with concomitant congenital heart disease in association with arrhythmias, those with atrial fibrillation and very young patients for whom transcatheter techniques are prohibitive because of small size, cyanosis or distorted anatomy. METHODS: From July 1992 through August 2003, 133 patients underwent arrhythmia surgery at Children's Memorial Hospital, 50% (67/133) in association with Fontan conversion (FC), 22% (28/133) with concomitant initial Fontan (IF) procedure and 28% (38/133) for various arrhythmias (MISC) in patients with (36/38, 95%) or without (2/38, 5%) associated structural heart disease. Mean age at surgery in the FC group was 20+/-7.6 years (median 19 years), and in the IF group and the MISC group, mean ages were 8.1+/-8.9 (median 4.2) years and 16.4+/-10.9 (median 11.3) years, respectively. RESULTS: There were three operative (3/133, 2.6%; 1 FC, 2 MISC) and three late deaths (2 FC, 1 MISC). Four patients in the FC group had progressive ventricular failure and underwent successful cardiac transplantation. Follow-up data are available for non-transplant, surviving patients and reveal 11 incidences of persistent arrhythmia recurrence and 2 new-onset arrhythmias. Five of the 11 recurrences occurred early in our series of FC patients, when isthmus block interruption of arrhythmia foci was performed. Four additional recurrences occurred later in the FC series, two post-maze and two post-Cox-maze III. In the MISC group, there were two recurrences. Atrial reentry tachycardia (ART) recurred in a patient with no structural heart disease and accessory connection-mediated tachycardia recurred in a child who underwent concomitant initial Fontan. Two patients had ventricular tachycardia inducible at postoperative studies (2/7, 29%), but no clinical recurrence. Two new-onset tachycardias occurred, one child developed ART post-surgical ablation of accessory connections and one patient with inducible ventricular tachycardia developed ART 5 years postoperatively. CONCLUSION: Variations in atrial and ventricular anatomy that may limit the catheter approach can be addressed surgically. Patient size or anatomic complexity should not be limiting factors in the combined surgical arrhythmia approach. Incorporation of arrhythmia therapy into planned surgical revision should be considered.

Adolescent↗
PubMed2004

Hypercholesterolemia is common after pediatric heart transplantation: initial experience with pravastatin.

BACKGROUND: Coronary allograft vasculopathy (CAV) is a progressive complication after cardiac transplantation and limits survival. Hyperlipidemia is a known risk factor for CAV, and pravastatin is effective in decreasing cholesterol levels in adults after transplantation. However, few data exist regarding lipid profiles and statin use after pediatric heart transplantation. We evaluated the prevalence of hyperlipidemia in pediatric heart transplant recipients and assessed the efficacy and safety of pravastatin therapy. METHODS: We performed a retrospective chart review of lipid profiles > or =1 year after surgery in 50 pediatric cardiac transplant recipients to assess the incidence of hyperlipidemia. Twenty of these patients received pravastatin for hypercholesterolemia. Their primary immunosuppression therapy was cyclosporine/prednisone plus either azathioprine or mycophenolate mofetil. We reviewed serial lipid profiles, creatinine phosphokinase, and liver enzymes. RESULTS: Overall, 36% of the patients (n = 50) had total cholesterol (TC) concentrations > 200 mg/dl and 52% had low-density lipoprotein (LDL) >110 mg/dL beyond 1 year after transplantation. Of the 20 treated with pravastatin, TC (236 +/- 51 vs 174 +/- 33 mg/dl) and LDL levels (151 +/- 32 vs 99 +/- 21 mg/dl) decreased significantly with therapy (p <.0001). We found no symptoms; however, 1 patient had increased creatinine phosphokinase. Liver enzyme concentrations remained normal in all. CONCLUSIONS: Hypercholesterolemia is prevalent in pediatric cardiac transplant recipients. Pravastatin therapy is effective in decreasing TC and LDL levels, seems to be safe, and is tolerated well. Further studies are necessary to determine whether pravastatin treatment is beneficial in decreasing CAV.

Adult↗
PubMed2004

The Aristotle score for congenital heart surgery.

The aim of the Aristotle project was to develop a new method of evaluation of quality of care in congenital heart surgery based on the complexity of the surgical procedures. Involving a panel of expert surgeons, the project started in 1999 and included 50 pediatric surgeons from 23 countries representing International Scientific Societies. The complexity was based on the procedures as defined by the Society of Thoracic Surgeons (STS)/European Association for Cadiothoracic Surgery (EACTS) International Nomenclature and was undertaken in two steps: The first step was establishing the Basic Score, which adjusts only the complexity of the procedures and is based on three factors: the potential for mortality, the potential for morbidity, and the anticipated technical difficulty. The second step was the development of the Comprehensive Score, which further adjusts the complexity according to the specific patient characteristics. The Aristotle score allows precise scoring of the complexity for 145 congenital heart surgery procedures. One interesting concept coming out of this study is that complexity is a constant and precise value for a given patient regardless of the center where he is operated. The Aristotle method allows proposing the following equation of quality of care: Complexity FN Outcome = Performance. The Aristotle score, electronically available, was introduced in the EACTS and STS databases. A validation process, designed to evaluate its predictive value, is being developed.

Cardiac Surgical Procedures↗
PubMed2003

Topical VEGF enhances healing of thoracic aortic anastomosis for coarctation in a rabbit model.

BACKGROUND: Recurrent stenosis after extended end-to-end anastomosis for aortic coarctation is the primary indication for further interventions in children. Tension because of the extended resection and local arterial wall hypoxia are possible pathogenetic mechanisms. We hypothesized that (1) tension interferes with healing and (2) that vascular endothelial growth factor (VEGF), a hypoxia sensitive angiogenic inducer, may enhance healing of the vascular anastomosis. METHODS AND RESULTS: In a model of coarctation repair, rabbits underwent thoracic aortic end-to-end anastomosis after transection (no-tension; n=15), resection of an aortic ring (tension; n=14) or resection and topical VEGF treatment (0.75 microg VEGF165; tension+VEGF; n=14). Gross and histologic characteristics of the aortic wall were assessed at 1 week, 1 and 2 months. In the tension only group at 1 month, the severity of vascular remodeling was increased with fibrosis and calcification compared with controls. At 2 months, this group also revealed more luminal stenosis (29% versus 19%; P<0.001). Exogenous VEGF resulted in significantly less fibrosis, calcification and chondroid metaplasia at 1 month (P<0.05) and luminal area was only reduced 3% at 2 months (P<0.001 versus tension group). CONCLUSIONS: In a rabbit model of coarctation repair, the addition of tension on the vascular anastomosis resulted in poor healing and luminal stenosis. Topical VEGF maintained luminal integrity by decreasing fibrosis and calcification. These findings suggest that topical VEGF may be a promising new strategy to enhance healing and improve the outcome of vascular anastomoses for coarctation of the aorta.

Administration, Topical↗
PubMed2003

Aprotinin reduces operative closure time and blood product use after pediatric bypass.

BACKGROUND: The use of aprotinin in children undergoing cardiopulmonary bypass is controversial. We hypothesized that aprotinin would reduce blood product use and operative closure time in selected pediatric patients. METHODS: For a 6-month period starting in October 1999, consecutive cardiopulmonary bypass patients 6 months of age or less (n = 18) or having a repeat sternotomy (n = 18) received aprotinin. Similar consecutive patients from the preceding 6 months served as controls (n = 35 and 41, respectively). Data extracted from medical records included preoperative clinical characteristics, operative and postoperative procedures, and total blood product use. RESULTS: Patients in the aprotinin and control groups were well matched with regard to preoperative and intraoperative variables. Patients 6 months of age or less who received aprotinin required less operative closure time when compared with controls (median, 93 vs 127 minutes, p = 0.004), and trended toward requiring fewer red blood cell unit exposures (median, three vs five exposures, p = 0.07). Patients undergoing repeat sternotomy who received aprotinin required less operative closure time when compared with controls (mean, 126 vs 159 minutes, p = 0.007), fewer red blood cell unit exposures (median three vs four exposures, p = 0.002), and fewer fresh-frozen plasma unit exposures (median, zero vs one exposure, p = 0.007). CONCLUSIONS: Aprotinin reduced operative closure time and blood product exposure in pediatric patients undergoing cardiopulmonary bypass who were 6 months of age or less or underwent a repeat sternotomy.

Aprotinin↗
PubMed2003

Beyond Fontan conversion: Surgical therapy of arrhythmias including patients with associated complex congenital heart disease.

BACKGROUND: Arrhythmia operations may be extended to patients with failed ablation procedures or associated structural defects requiring surgical intervention. The purpose of this study is to review our experience with arrhythmia operations in 29 patients who did not have Fontan conversions after the introduction of catheter ablation. METHODS: Between July 1992 and January 2002, 29 patients had operations for refractory atrial (n = 24) or ventricular (n = 5) arrhythmias. Mechanisms of arrhythmia included atrial reentry (n = 11), atrial fibrillation (n = 5), automatic atrial (n = 3), accessory connections (n = 6), atrioventricular nodal reentry (n = 2), and ventricular tachycardia (n = 5). Median age at operation was 12.3 years (range, 6 days to 45 years). Two patients had structurally normal hearts; the remaining 27 patients underwent concomitant repair of structural heart disease, including atrioventricular valve replacement or repair (n = 8), anatomy-specific repair of Ebstein's anomaly (n = 4), tetralogy of Fallot repair or revision (n = 4), atrial septal defect closure (n = 3), ventricular septal defect repair (n = 2), Mustard takedown with arterial switch (n = 2), initial Fontan (n = 2), right ventricle-to-pulmonary artery conduit revision (n = 2), Norwood procedure (n = 1), 1 ventricular repair for Uhl's anomaly (n = 1), Mustard baffle revision (n = 1), pulmonary valve replacement with aneurysm resection (n = 1), and aortic valve replacement with complex repair (n = 1). RESULTS: No patient developed heart block, and the surgical mortality rate was 7%. One patient died after Mustard takedown and arterial switch operation, and 1 neonate died after repair of severe Ebstein's anomaly. There was one late death after arterial switch conversion at another institution. Recurrent clinical supraventricular tachycardia was present in 2 patients (2 of 27, 7.4%) and 2 patients had new-onset tachycardias with different underlying mechanisms of arrhythmia at late follow-up (median follow-up 47 months). CONCLUSIONS: Successful surgical therapy of arrhythmias can be performed safely at the time of repair of complex congenital heart disease or in patients with failed catheter ablation procedures. Early consideration for single-stage therapy of arrhythmia and structural heart disease is indicated.

Adolescent↗
PubMed2003

The incidence of dysphagia in pediatric patients after open heart procedures with transesophageal echocardiography.

BACKGROUND: Pediatric patients who undergo open heart operations may be at risk for the development of dysphagia because of interventions such as intubation and transesophageal echocardiography. Although the occurrence of dysphagia after cardiac surgical procedures in adults is reported to be 3% to 4%, the incidence in children and adolescents has not been documented. This study was undertaken to determine the incidence of and risk factors contributing to dysphagia in pediatric patients after open heart procedures. METHODS: Fifty patients were evaluated after open heart operations with transesophageal echocardiography between March 1, 1999, and September 30, 1999. The diagnosis of dysphagia was made by a speech pathologist using a clinical swallowing evaluation. Potential predictors examined included demographic variables, anatomical diagnosis, surgical procedure, size of the transesophageal echocardiographic probe in relation to body size, length of probe insertion time, preoperative patient acuity status, duration of intubation, and time until discharge. RESULTS: Dysphagia was found in 9 (18%) of the 50 patients. Risk factors identified were age of less than 3 years (odds ratio, 20.4; 95% confidence interval, 2.7 to 157; p = 0.002), intubation prior to operation (odds ratio, 17.7; 95% confidence interval, 9.4 to 210; p = 0.004), intubation for more than 7 days (odds ratio, 74.7; 95% confidence interval, 13.8 to 405; p = 0.001), and operation for left-sided obstructive lesions (odds ratio, 1.9; 95% confidence interval, 2.2 to 8.3; p = 0.038). The size of the transesophageal echocardiographic probe in relation to the weight of the patient was found to be predictive (p = 0.0001) of dysphagia. Vocal cord paralysis was noted in 4 (8%) of the 50 patients postoperatively. Adverse events related to aspiration occurred in 2 patients (4%). At discharge, nasogastric tube feedings were required in 6 patients (12%), and thickened feedings were recommended for 3 (6%) of the 50 patients. Resolution of dysphagia ranged from 13 to 150 days. CONCLUSIONS: Eighteen percent of patients had dysphagia after an open heart operation with transesophageal echocardiography. Age of less than 3 years, preoperative patient acuity status, longer intubation times, and operation for left-sided obstructions are risk factors for dysphagia in this cohort of pediatric patients. The size of the transesophageal echocardiography probe in relation to the patient's weight was predictive of dysphagia. Physicians should consider using the new mini-multiplane transesophageal echocardiographic probes in patients weighing less than 5.5 kg. Vigilance in monitoring for the signs of preoperative and postoperative dysphagia with prompt referral to a speech therapist can substantially reduce patient morbidity, length of hospital stay, and requirement of prolonged nasogastric tube use.

Adolescent↗
PubMed2003

The Southern Thoracic Surgical Association 50th anniversary celebration: the impact of STSA pediatric cardiothoracic surgery manuscripts on surgical practice.

BACKGROUND: Members of the Southern Thoracic Surgical Association (STSA) have presented important pediatric cardiothoracic surgery papers at the annual meetings over the last 50 years. In order to determine the influence of these presentations on the practice of surgery, a review was undertaken. Early papers were characterized by emerging advances in open-heart surgery, anatomic congenital heart studies, and electrophysiologic discoveries that extended life with pacemakers. Later years were characterized by innovative myocardial preservation methods, improved cardiopulmonary bypass techniques, expanded homograft availability, emphasis on accurate repairs, intraoperative transesophageal echocardiography, and cardiopulmonary transplantation. METHODS: All but one of the scientific programs of the annual meetings (that of 1964) were located. The programs were reviewed and 180 presentations were identified on topics in congenital heart disease, pediatric thoracic disease, and pediatric thoracic wall abnormalities. Of those 180 oral presentations, 155 manuscripts (86%) were eventually published or in press and available for critical review and analysis. Manuscripts were grouped by diagnosis or therapeutic intervention. We determined a "cumulative citation frequency" (CCF), which measures the number of times an article is cited in the bibliography of related papers in the universe of participating journals. The selected manuscripts were compared with the historic landmark contributions and the existing trends at the time, and the number of articles both by individual authors and from institutions were tallied. RESULTS: Grouping by authors and institutions showed that 100 of 155 pediatric cardiothoracic manuscripts (65%) originated from 13 institutions. The CCF for the 20 leading articles ranged from 26 to 93. CONCLUSIONS: This historical STSA 50-year record of pediatric cardiothoracic advances was accomplished in a milieu of collegial respect and camaraderie. Our annual meetings over the years have provided a venue for thoracic surgeons to share their ideas, innovations, and scientific inquiry. These contributions have significantly affected the practice of pediatric cardiothoracic surgery. The STSA has worked for 50 years and we trust that it will work for another 50 years and beyond.

Bibliometrics↗
PubMed2003

Outcomes of 829 neonates with complete transposition of the great arteries 12-17 years after repair.

OBJECTIVE: Between 1985 and 1989, the surgical management of neonates with complete transposition (TGA) underwent a transition from atrial to arterial repair. We sought to examine the intermediate outcomes and their associated risk factors in neonates repaired during the era of transition. PATIENTS AND METHODS: Twenty-four institutions entered 829 neonates age less than 15 days in a prospective study. Diagnosis was simple TGA (n=631), TGA with ventricular septal defect (VSD) (n=167), TGA with VSD and pulmonary stenosis (TGA/VSD/PS) (n=30), or TGA with PS (n=1). Repair was by arterial switch (n=516), atrial repair (Senning=175, Mustard=110) or Rastelli (n=28). Time-related events were analysed by parametric hazard function modeling and incremental risk factors for mortality, re-intervention, and late functional assessment were sought. RESULTS: Survival estimates at 6 months, 5, 10, and 15 years are 85, 83, 83, and 81%, respectively. The hazard function for death after repair has two phases: an early rapidly declining phase and an ongoing constant one. Constant phase mortality is less likely after the arterial switch operation and in children with simple TGA. During follow up, at least one re-intervention was required in 167 children (pacemaker, n=35; percutaneous intervention, n=32; baffle re-intervention, n=27; re-operation, n=125). Freedom from re-intervention at 6 months, 5, 10 and 15 years is 93, 82, 77, and 76%, respectively. Of survivors, 87% have been followed up to the last 3 years, including an assessment of functional ability of 562 children (83%). Functional class 15 years after repair is class I in 76%, II in 22%, III in 2%. The proportion in functional class I decreased over time. Psychosocial deficits, especially learning disorders are prevalent. CONCLUSIONS: Survival 15 years after TGA repair is good with most children functioning well, and results are best after an arterial switch operation. There is an ongoing risk of death that is less after the arterial switch operation. With the exception of Rastelli patients, the likelihood of survivors needing re-intervention after 5 years is low. There is need for improved neurodevelopmental outcomes.

Arteries↗
PubMed2003

A comparison of intravascular ultrasound with coronary angiography for evaluation of transplant coronary disease in pediatric heart transplant recipients.

BACKGROUND: The purpose of this study was to assess the sensitivity of coronary angiography versus intravascular ultrasound for detecting significant transplant coronary artery disease in children. We also examined associations between potential risk factors for transplant coronary artery disease and intravascular ultrasound findings, and evaluated the safety of intravascular ultrasound. METHODS: All pediatric heart transplant patients who had intravascular ultrasound following routine coronary angiography were included. Transplant coronary artery disease was quantified by assigning Stanford classes and calculating intimal indices for intravascular ultrasound images. These findings were compared with qualitative coronary angiography findings. Risk factors for transplant coronary artery disease, cardiac events and complications were recorded. RESULTS: Sixteen patients had 27 intravascular ultrasound procedures during the study period. All patients had evidence of transplant coronary artery disease at their latest intravascular ultrasound study. Of the patients whose most severely afflicted coronary artery underwent both imaging modalities at the latest study, 50% had significant transplant coronary artery disease (Stanford Class >/=II) by intravascular ultrasound and normal coronary angiography. A higher mean first-year biopsy score may be associated with significant transplant coronary artery disease by intravascular ultrasound, but a large number of patients will be required to determine this with statistical certainty. One major complication occurred early in the experience. CONCLUSIONS: In children, intravascular ultrasound is more sensitive for detecting significant transplant coronary artery disease than coronary angiography, but may add cost, time and potential morbidity to screening protocols. Prospective, multicenter studies are needed to best utilize intravascular ultrasound in this patient population.

Adolescent↗
PubMed2003

The effect of pulmonary circulation hemodynamics on right ventricular unloading via the bidirectional Glenn shunt: implications for congenitally corrected transposition repair.

The bidirectional Glenn shunt has been successfully applied as an adjunct to ventricular septal defect closure and pulmonary valvulotomy to treat congenitally corrected transposition of the great arteries (ccTGA). The purpose of this study was to examine the volume and pressure unloading effects of the bidirectional Glenn shunt on the hypertrophied pulmonary ventricle in a canine model of ccTGA. Five beagles underwent survival surgery to band the pulmonary artery. Three months later, a polytetrafluoroethylene graft was anastomosed to the superior vena cava and right pulmonary artery. The graft or superior vena cava was clamped to create the normal or bidirectional Glenn circulation, and hemodynamic data were recorded. The bidirectional Glenn shunt significantly reduced right ventricular volume loading and stroke work. Dogs with normal pre-bidirectional Glenn cardiac outputs had greatly reduced right ventricular volumes and pressures with the bidirectional Glenn shunt. Dogs with pre-bidirectional Glenn right ventricular dysfunction had moderate volume but no pressure decreases with the bidirectional Glenn shunt owing to improved left ventricular output. In these dogs it is likely that the decreased level of pressure and volume unloading is because of a concomitant improvement in left ventricular output post-bidirectional Glenn shunt placement. The bidirectional Glenn shunt is effective at unloading the right ventricle in a canine model of ccTGA.

Animals↗