PubMed Health⌕ Search

Biomedical subjects

Robert N Vincent

Publications and source records attributed to Robert N Vincent.

At least 19 recordsLinked to original sources
PubMed2007

Cerebral near infrared spectroscopy is a reliable marker of systemic perfusion in awake single ventricle children.

Clinical assessment of systemic perfusion in single ventricle patients with parallel circulation can be difficult in the outpatient setting. Near infrared spectroscopy (NIRS) is a noninvasive measure of cerebral oximetry. We measured vital signs, pulse oximetry, and NIRS in 20 single ventricle patients with parallel circulation prior to routine cardiac catheterization. These variables were evaluated to determine the best noninvasive predictor of the superior vena cava saturation (SVC(sat)) as a marker for the adequacy of systemic oxygen delivery. The mean age was 6.7 months [standard deviation (SD), 8.6] and mean weight was 6.5 kg (SD, 2.2). Diagnoses were hypoplastic left heart syndrome (8), tricuspid or pulmonary atresia (10), and double-outlet right ventricle variants (2), all prior to cavo pulmonary anastomoses or complete repairs. Stepwise multiple regression analysis generated a model in which only NIRS was a significant independent predictor of SVC(sat) (p = 0.009). These results support the conclusion that NIRS can be a useful tool to evaluate awake single ventricle patients in the outpatient setting.

Biomarkers↗
PubMed2007

Right ventricular outflow tract and pulmonary artery stents in children under 18 months of age.

OBJECTIVE: To report our experience on patients less than 18 months of age in whom stents were placed either in the right ventricular outflow tract (RVOT) or pulmonary arteries. BACKGROUND: Although percutaneous placement of intravascular stents in congenital heart disease is common practice, there are few reports regarding placement in young children. METHODS: Retrospective review of our database identified 19 patients less than 18 months of age who underwent placement of 26 stents in either the RVOT or pulmonary arteries. Data evaluated were patient age, gender, weight, site of narrowing, type of stent, gradient across the area of narrowing pre- and post-stent placement, vessel size pre- and post-stent placement, gradient, and vessel size on followup, and ability to redilate the stent if necessary. RESULTS: Mean patient age was 9.7 months (range 0.5-17.5 months). There were 14 males and 5 females with a mean weight of 7.1 kg (range 2.3-10.2 kg). Five patients had stents placed in the RVOT and 14 patients had 21 stents placed in the branch pulmonary arteries. Two Johnson and Johnson P188 stents were used, 23 premounted Genesis biliary stents and 1 other. Gradient across the stenotic area decreased from a mean of 52.9 mm Hg (range 20-80 mm Hg) to 15 mm Hg (range 3-40 mm Hg) (P<.001). CONCLUSIONS: Percutaneous placement of intravascular stents in young children is a viable procedure, can provide excellent relief of stenoses, and increases vessel size in the short term. Although many of these stents cannot be dilated to adult size, their efficacy in small infants and children in whom further surgery will ultimately be required makes them desirable for this group of patients.

Coronary Angiography↗
PubMed2006

Reduction in initial ventricular systolic and diastolic velocities after heart transplantation in children: improvement over time identified by tissue Doppler imaging.

BACKGROUND: Tissue Doppler imaging (TDI) is a non-invasive method for measuring ventricular function that can provide insight into the changes in hemodynamics that occur after pediatric heart transplantation. The purpose of this study was to quantify longitudinal changes in myocardial velocities within the first 6 months after transplantation in children. METHODS: Thirteen patients were serially studied (median age at transplant 5.9 years) and compared with controls. Tissue Doppler systolic (S), early (E) and late (A) diastolic velocities were recorded at the tricuspid annulus, mitral annulus and interventricular septum. RESULTS: TDI studies were serially performed during 6 months post-transplantation: <10 days (n = 48); 11 to 30 days (n = 26); 31 to 60 days (n = 13); 61 to 120 days (n = 12); and 121 to 180 days (n = 16). Mean systolic tissue velocities at the tricuspid annulus were 3.8 cm/s (95% confidence interval [CI]: 3.1 to 4.6) at baseline (<10 days) and 6.3 cm/s (95% CI: 4.1 to 8.6) at 6 months post-transplantation (mean increase from baseline: 2.5 cm/s; 95% CI: 0.1 to 4.9). Systolic tissue velocities at the mitral annulus also increased over time (mean change from baseline: 0.9 cm/s; p = 0.02). Early diastolic (E) velocities at the tricuspid annulus and mitral annulus significantly improved over time (p < 0.0001 and p = 0.002, respectively). Systolic and diastolic velocities measured at >121 days after transplantation, however, remained significantly lower than those of normal controls. CONCLUSIONS: TDI demonstrated systolic and diastolic velocities improved during the initial 180 days after heart transplantation. Systolic and diastolic velocities were reduced in children after heart transplantation when compared with controls.

Adolescent↗
PubMed2006

Cost-effectiveness of pediatric heart transplantation.

BACKGROUND: Survival after pediatric heart transplantation has continued to improve. Nonetheless, graft survival is generally <15 years and the costs of transplantation and subsequent immunosuppression are substantial. In the present study, we sought to examine the cost-effectiveness of pediatric heart transplantation. METHODS: Data from 95 pediatric subjects undergoing transplantation at our institution from 1997 through 2004 were reviewed to determine the costs of pediatric heart transplantation. Costs included pre-transplant care, organ procurement, initial hospitalization and follow-up care. Life expectancy was derived from the United Network of Organ Sharing data set. Data were reported as cost per quality-adjusted life-years (QALYs) gained, which were discounted at 3%. Cost-effectiveness was stratified by primary transplantation vs re-transplantation. RESULTS: The mean cost of initial hospitalization and organ procurement was $221,897 per patient for primary transplant and $285,296 per patient for re-transplant. Annual follow-up costs were estimated to be $18,141 in the first year (excluding the first 90 days post-transplant) and $18,480 per year thereafter. Under base-case assumptions, costs per QALY gained were $49,679 for primary transplantation and $87,883 for re-transplantation. Sensitivity analysis yielded a cost-utility range of $44,943 to $57,628 per QALY gained for primary transplantation and $70,834 to $103,661 per QALY gained for re-transplantation. CONCLUSIONS: Costs of primary pediatric heart transplantation are within the accepted range of cost effectiveness. Pediatric heart re-transplantation has higher costs relative to benefits gained owing to shorter graft survival.

Adolescent↗
PubMed2006

Left ventricular aneurysm in a five-week-old child.

Ventricular aneurysms in the pediatric population are rare and no standardized method of treatment exists. We present a case of left ventricular (LV) aneurysm in an infant, 5 weeks after a balloon aortic valvuloplasty for congenital aortic stenosis.

Aortic Valve Stenosis↗
PubMed2005

Use of a 3 French system for balloon aortic valvuloplasty in infants.

For infants with valvar aortic stenosis, balloon aortic valvuloplasty has supplanted surgical valvotomy as the initial treatment of choice at most institutions. Technological innovations have resulted in further miniaturization of balloon dilation catheters, allowing this procedure to be performed through smaller sheath sizes. Currently, the Tyshak-Mini balloon dilation catheter (B. Braun Medical) allows passage of up to an 8 mm dilation balloon catheter through a 3 Fr hemostatic sheath. The efficacy of this system for the treatment of valvar aortic stenosis in infants less than 6 months of age was evaluated in 20 patients undergoing 22 procedures. Mean age at the time of intervention was 26 +/- 46 days. Mean transvalvar gradient was 76 +/- 22 mm Hg prior to balloon dilation. Following balloon valvuloplasty, residual gradient was 26 +/- 12 mm Hg, reflecting a mean change in peak-to-peak gradient of 49 +/- 19 mm Hg. Postintervention increase in aortic insufficiency was one grade or less in 19/22 procedures, two grades in 2 procedures, and three grades in 1 procedure. There were no significant vascular complications reported immediately following the procedure. Repeat valvuloplasty was performed in three patients in which the 3 Fr system was used in two patients. The 3 Fr system for balloon aortic valvuloplasty in infants less than 6 months of age is effective and safe.

Aortic Valve Stenosis↗
PubMed2005

Pravastatin therapy is associated with reduction in coronary allograft vasculopathy in pediatric heart transplantation.

BACKGROUND: Hydroxymethylglutaryl CoA reductase inhibitors (statins) have been demonstrated to reduce the risk of developing coronary allograft vasculopathy (CAV) following heart transplantation in adults and are used routinely in many centers. CAV and lipid abnormalities have been reported to be less prevalent in pediatric heart transplant recipients. It is not known whether statins reduce the risk of CAV in this population METHODS: A retrospective review was performed to analyze the risk factors for developing CAV following pediatric heart transplantation with particular attention to the impact of pravastatin therapy. The study population was comprised of 129 pediatric patients who underwent 142 heart transplants at our institution from 1988 to 2003. The outcome variable was freedom from CAV, CAV being determined by coronary angiography or autopsy. RESULTS: CAV was identified in 25 recipients at a median of 3.7 years after transplantation. There were 331 patient-years of pravastatin therapy. Pravastatin therapy resulted in a reduction in total cholesterol levels, 162 +/- 29 to 137 +/- 20 mg/dl, p = 0.01. In multivariate analysis the use of pravastatin was associated with a lower incidence of CAV (p = 0.03), whereas an increased frequency of late rejection (p = 0.003) and earlier year of transplantation (p = 0.04) were associated with increased risk of CAV. CONCLUSIONS: The routine use of pravastatin was associated with a lower risk following pediatric heart transplantation. Further studies into the relationship between lipid abnormalities, inflammation and rejection, and the development of CAV in children are warranted.

Adolescent↗
PubMed2005

OKT3 treatment in refractory pediatric heart transplant rejection.

BACKGROUND: The anti-lymphocyte monoclonal antibody OKT3 has been shown to be effective in the management of steroid-resistant and/or fulminant heart transplant rejection in adults. In addition, some studies suggest that OKT3 may have a role in the management of transplant coronary artery disease (TxCAD). To date, there are limited data regarding the use of OKT3 treatment of refractory rejection or graft failure in children. Our study examines OKT3 treatment in steroid-resistant rejection, rejection with hemodynamic compromise, and TxCAD in children. METHODS: Thirty-eight patients received 53 courses of OKT3 for treatment of rejection and/or graft dysfunction. Primary indications for OKT3 were steroid-resistant rejection (n = 27), rejection with hemodynamic compromise (n = 22), and TxCAD (n = 4). Resolution of rejection was considered absence of biopsy-proven rejection (< grade 2) or resolved TxCAD. RESULTS: OKT3 use in steroid-resistant rejection was associated with a lower incidence of rejection in the 3 months after OKT3 than 3 months before OKT3, median rejection episodes of 2.5 vs 0, p < 0.0001. In rejection with hemodynamic compromise, 20 subjects (91%) demonstrated improved hemodynamics after OKT3 and survived to hospital discharge. The use of OKT3 treatment for TxCAD failed to demonstrate resolution or improvement in angiographic TxCAD in any subject. Only 5 OKT3 treatment courses were stopped secondary to severe adverse side effects. CONCLUSIONS: OKT3 treatment in refractory pediatric heart transplant rejection is efficacious in acute rejection. OKT3 management in pediatric TxCAD is less clear, with no proven benefit identified in this study. OKT3 use in pediatric refractory heart rejection has significant side effects, but is tolerable and safe with close monitoring.

Adolescent↗
PubMed2005

Disparities in outcome for black patients after pediatric heart transplantation.

OBJECTIVE: To examine the relationship of black race to graft survival after heart transplantation in children. STUDY DESIGN: United Network for Organ Sharing records of heart transplantation for subjects <18 years of age from 1987 to 2004 were reviewed. Analysis was performed using proportional hazards regression controlling for other potential risk factors. RESULTS: Of the 4227 pediatric heart transplant recipients, 717 (17%) were black. The 1-year graft survival rate did not differ among groups; however, the 5-year graft survival rate was significantly lower for black recipients, 51% versus 69%, P < .001. The median graft survival for black recipients was 5.3 years as compared with 11.0 years for other recipients. Black recipients had a greater number of human leukocyte antigen mismatches, lower median household income, and a greater percentage with Medicaid as primary insurance, P < .001, P < .001, and P < .001. After adjusting for economic disparities, black race remained significantly associated with graft failure, odds ratio = 1.67 (95% CI 1.47 to 1.87), P < .001. CONCLUSIONS: Median graft survival after pediatric heart transplantation for black recipients is less than half that of other racial groups. These differences do not appear to be related primarily to economic disparities.

Adolescent↗
PubMed2005

Cardiac retransplantation in childhood: analysis of data from the United Network for Organ Sharing.

OBJECTIVE: For children in whom graft failure develops after cardiac transplantation, retransplantation is often considered. Although some centers have reported equivalent results for retransplantation as for primary transplantation, this strategy remains controversial. We sought to examine outcomes after retransplantation in children and to identify risk factors for mortality. METHODS: United Network for Organ Sharing records of heart transplantation for subjects younger than 18 years from 1987 to 2004 were reviewed. Indications for retransplantation and patient characteristics were evaluated. Analysis was performed with proportional hazards regression, controlling for other potential risk factors. RESULTS: Among the 4227 pediatric heart transplants, there were 219 retransplants. The most common indication for retransplantation was coronary allograft vasculopathy (51%). The mean interval from initial heart transplant to retransplantation was 4.7 +/- 3.8 years. Forty-two retransplants (19%) were performed within 180 days of primary transplantation. Survivals at 1, 5, and 10 years after retransplantation were 79%, 53%, and 44%, respectively. In multivariate analysis, retransplantation was associated with significantly higher mortality than primary transplantation (odds ratio 1.67, 95% confidence interval 1.32-2.12, P < .001). Patients who underwent retransplantation within 180 days of primary transplantation had a significantly lower 1-year survival than did other retransplant recipients (53% vs 86%, respectively, P < .02). Subjects who required mechanical ventilation before retransplantation also had poorer survival (P < .03). CONCLUSION: Survival after cardiac retransplantation in children is inferior to that after primary transplantation. Although results are acceptable, the impact of retransplantation on the availability of donor hearts requires further consideration.

Adolescent↗
PubMed2004

Mechanical thrombectomy using the AngioJect in a child with congenital heart disease.

Acute thrombosis of a vascular channel can be a serious and perhaps fatal complication. We describe a patient who developed complete thrombosis of the left pulmonary artery following catheter placement of a stent in this vessel shortly after open heart surgery. The thrombosis was successfully removed using the Possis AngioJet mechanical thrombectomy catheter.

Cardiac Catheterization↗
PubMed2004

Cardiac retransplantation in children.

BACKGROUND: Experience with pediatric cardiac retransplantation is limited. Outcomes should be inspected to insure proper use of donor hearts. METHODS: Of 152 pediatric heart transplantations, we performed 20 retransplants in 17 children (3 had a second retransplant). The retransplant children were older than the primary transplant children (11.1 +/- 4.4 years versus 7.1 +/- 6.0 years; p = 0.005). Excluding 1 early retransplant, the interval from primary transplant to retransplant was 5.5 +/- 3.3 years (range, 1.1 to 11.1). The retransplant patients were clinically more ill than the primary transplant patients (United Network for Organ Sharing status I, 75% versus 63%; mechanical circulatory support or dialysis, 20% versus 3.8%). RESULTS: Donor ischemia time (188 versus 165 minutes) and cardiopulmonary bypass time (127 versus 127 minutes) were not significantly different for the retransplant patients. Excluding 1 retransplant patient who required a tracheostomy, days on the ventilator (2.7 versus 2.7), days on inotropic support (3.0 versus 3.2), intensive care unit days (7.2 versus 6.7), and hospital days (15.9 versus 13.8) were similar in the retransplant group. Freedom from rejection at 90 days and 1 year was not different in the retransplant patients. Actuarial patient survival in the patients undergoing first retransplant was similar to the primary transplant patients at 30 days (95% versus 94.7%), 1 year (94.1% versus 80.7%), and 3 years (78.4% versus 73.1%). Two of 3 children receiving a third transplant died within 1 year of redo retransplantation. CONCLUSIONS: Cardiac retransplantation can be performed in children with results comparable with those for primary transplantation despite increased clinical acuity. These early results suggest that cardiac retransplantation in children is a reasonable therapeutic option. Children with repeat retransplantation do not fare as well.

Adolescent↗
PubMed2004

The short term effects of cardiopulmonary bypass on neurologic function in children and young adults.

OBJECTIVE: Cognitive deficits are common in adults following surgery utilizing cardiopulmonary bypass (CPB). A previous retrospective study suggested that surgical closure of an ASD in children was associated with neurologic injury, while transcather therapy was not. In a prospective study, we sought to determine whether neurologic deficits occur following repair of non-complex congenital heart lesions in school-age children and young adults. METHODS: Inclusion criteria were: age between 5 and 20 years, cardiac surgery utilizing CPB without deep hypothermic circulatory arrest, and no prior cardiac surgery. Patients underwent psychometric testing 1-3 days prior to surgery and re-evaluation 7-18 days after surgery. In order to determine the test/re-test effect an age-matched cohort of children undergoing transcather closure of ASD under general anesthesia was also evaluated. The primary outcome measures were verbal and picture memory. Additional psychometric tests included: computerized performance test (CPT) and Digit Span (DS). Forty-one patients were enrolled, 29 undergoing surgery with CPB and 12 controls. Surgical procedures included ASD closure (n=13), VSD closure (n=10), resection of sub-aortic stenosis (n=3), mitral valvuloplasty (n=3). Mild hypothermia was used in all cases. The mean duration of CPB was 54+/-22 min. RESULTS: There was no significant difference in any of the psychometric test scores between subjects undergoing surgery with CPB or controls. CONCLUSIONS: There are no marked adverse neurologic effects of CPB in school-age children and young adults undergoing non-complex open-heart surgery. These data are important in counseling patients and families and should be considered in the debate as to the relative merits of transcather versus open-heart repair of various heart lesions.

Adolescent↗
PubMed2003

Deletion of chromosome 22q11.2 and outcome in patients with pulmonary atresia and ventricular septal defect.

BACKGROUND: The 22q11.2 deletion (del22q) is present in many patients with conotruncal abnormalities including pulmonary atresia with ventricular septal defect (PA/VSD). We sought to determine the impact of the del22q on outcome in subjects with PA/VSD. METHODS: We reviewed the experience for all patients with PA/VSD who were born between January 1993 and April 2002 and presented to our institution. Patients with conotruncal defects were routinely evaluated for genetic disorders including del22q. Fluorescence in situ hybridization was used to test for del22q. RESULTS: There were 67 subjects with PA/VSD who presented during that time period; testing for del22q was performed in 58 of 67 (87%) and these 58 patients comprised the study population. The 22q11.2 deletion was present in 20 of 58 (34%) patients tested. Major aortopulmonary collaterals were defined by angiography and were present in 27 (47%). These collaterals were significantly more common among subjects with del22q (13 of 20, 65%; p = 0.04). The median cross sectional area of the pulmonary arteries, the Nakata index, was significantly less for patients with del22q (41 versus 142 mm(2)/m(2); p = 0.006). There were 3 subjects, all of whom had del22q, who did not undergo surgery owing to markedly hypoplastic pulmonary arteries. Of the remaining 55 patients, 53 had arteriopulmonary shunt with or without unifocalization as the initial procedure and 35 patients have undergone complete repair. There were 8 operative deaths and 1 nonoperative death. The 5-year survival was 36% for patients with del22q versus 90% for patients without del22q. The 22q11.2 deletion was a significant risk factor for death, even after adjusting for the presence of major aortopulmonary collaterals (p = 0.004). There was no significant difference between the two groups with respect to the incidence of serious viral, bacterial, or fungal infections in the perioperative period. CONCLUSIONS: Patients with del22q and PA/VSD are at increased risk for death owing to a variety of factors including less favorable pulmonary artery anatomy. A better understanding of del22q, pulmonary artery anatomy, and outcome is required.

Abnormalities, Multiple↗
PubMed2003

Reduction of tricuspid annular doppler tissue velocities in pediatric heart transplant patients.

BACKGROUND: Orthotopic heart transplantation is a life-saving therapy for children with end-stage heart disease. However, 50% of these transplanted children die or require re-transplantation 12 years later. Progressive deterioration of cardiac function is a common feature of long-term survivors; however, quantitative evaluation of the state of the right ventricle has been lacking. Tissue Doppler imaging (TDI) has been used to measure alterations in right ventricular (RV) function in other illnesses. The purpose of this study was to quantitate abnormalities in tricuspid annular systolic and diastolic velocities as an indicator of RV dysfunction, and to evaluate if time since transplantation and the presence of tricuspid regurgitation are associated with quantitative changes in tricuspid annular velocities in pediatric heart transplant recipients. METHODS: TDI was performed and velocities recorded during systole and early and late diastole at the tricuspid annulus, septum and mitral annulus in transplanted patients and in a control group with normal hearts. Pulsed wave Doppler mitral and tricuspid inflows were also measured and the severity of tricuspid regurgitation was estimated using color flow mapping. Patients with biopsy evidence of active cellular rejection or left ventricular ejection fraction of <60% were excluded from study. RESULTS: Thirty-five patients were divided into a normal heart group (n = 14) and a transplant group (n = 21), aged from 1 to 23 years. Systolic and early diastolic velocities at the tricuspid annulus and septum in the transplant group were reduced significantly compared with the normal group (p < 0.05): tricuspid annular systolic, 5.8 +/- 1.4 vs 9.4 +/- 1.7 cm/sec; early diastolic, -6.4 +/- 2.6 vs -9.7 +/- 2.6 cm/sec; septum systolic, 3.9 +/- 1.5 vs 5.8 +/- 1.4 cm/sec; and early diastolic, -6.3 +/- 2.4 vs -9.1 +/- 2.5 cm/sec. Patients were divided into early (<5 years) and late (>5 years) term groups since transplantation. Tissue velocities at the tricuspid annulus in the late term group had further reduction in systole, 4.9 +/- 1.4 vs 6.4 +/- 1.1 cm/sec, and early diastole, -5.3 +/- 1.5 vs -7.1 +/- 2.9 cm/sec (p < 0.05). Patients with severe tricuspid regurgitation had systolic and early diastolic velocities at the tricuspid annulus that were further reduced. Left ventricular mitral inflow Doppler early/late diastolic ratios became significantly different from the normal group 5 years after transplantation (p < 0.05). CONCLUSIONS: TDI demonstrated that tricuspid annular systolic and early diastolic velocities were abnormal in children after transplantation and became significantly more abnormal with prolonged time after transplantation. These alterations were not dependent on the presence of severe tricuspid regurgitation but appeared to be exacerbated by its presence. Evidence of diastolic left ventricular dysfunction was not detected before 5 years after transplantation in this unselected group. A prospective study may be required to define the evolution and progression of right and left ventricular dysfunction in children after heart transplantation.

Adolescent↗
PubMed2003

Single-center experience with the HELEX septal occluder for closure of atrial septal defects in children.

Catheter closure of atrial septal defects (ASDs) is an accepted procedure among pediatric cardiologists. We report our early experience with the newest of these devices in clinical trials in the United States. Between April and October 2001, 14 patients were enrolled in an FDA phase II multicenter trial comparing the results of ASD closure using the HELEX Septal Occluder to a surgical control group. Of the 14 patients, devices were placed and left in 13, one being removed for an excessive residual leak despite placing the largest device available. Of the remaining 13 patients, all patients had successful closure of their defects. An average of 1.8 devices/patient were deployed, reflecting the learning curve for this new device and new delivery style. Six devices were replaced because of excessive residual leaks, three for premature lock release, and two for improper seating of the device. There were no procedural complications, however, one patient required device removal 4 months postimplant for possible allergic reaction to nickel. The same patient had removal of stainless steel sternal wires for the same reason. At the 6-month follow-up, 11 of 13 patients had complete closure of the ASD, the other two having small, hemodynamically insignificant left to right shunts. In one of these patients, there was complete closure at the 12-month follow-up, whereas the other patient awaits the 1-year evaluation. Early experience at our institution has demonstrated the ease of use of this device, its complete retrievability, and excellent closure of small to moderate ASDs in children.

Adolescent↗
PubMed2003

Unusual stents in infants with severe congenital heart disease.

Two infants with severe congenital heart disease requiring intervention are described. Although both required conventional surgical therapy, mitigating circumstances led to catheter intervention for short-term palliation. The feasibility and advisability of such procedures is discussed.

Cardiac Catheterization↗