Palaniswamy Vijay

Effect of modified ultrafiltration in high-risk patients undergoing operations for congenital heart disease.

BACKGROUND Modified ultrafiltration (MUF) after cardiopulmonary bypass (CPB) in children decreases body water, removes inflammatory mediators, improves hemodynamics, and decreases transfusion requirements. The optimal target population for MUF needs to be defined. This prospective, randomized study attempted to identify the best candidates for MUF during operations for congenital heart disease. METHODS Informed consent was obtained from 100 consecutive patients with complex congenital heart disease undergoing operations with CPB. They were randomized into a control group (n = 50) of conventional ultrafiltration during bypass and an experimental group using dilutional ultrafiltration during bypass and venovenous modified ultrafiltration after bypass (MUF group, n = 50). Postoperative arterial oxygenation, duration of ventilatory support, transfusion requirements, hematocrit, chest tube output, and time to chest tube removal were compared between the groups stratified by age and weight, CPB technique, existence of preoperative pulmonary hypertension, and diagnosis. RESULTS There were no MUF-related complications. In patients with preoperative pulmonary hypertension, MUF significantly improved postoperative oxygenation (445 +/- 129 mm Hg versus control: 307 +/- 113 mm Hg, p = 0.002), shortened ventilatory support (42.9 +/- 29.5 hours versus control: 162.4 +/- 131.2 hours, p = 0.0005), decreased blood transfusion (red blood cells: 16.2 +/- 18.2 mL/kg versus control: 41.4 +/- 27.8 mL/kg, p = 0.01; coagulation factors: 5.3. +/- 6.9 mL/kg versus control: 32.3 +/- 15.5 mL/kg, p = 0.01), and led to earlier chest tube removal. In neonates (< or =30 days), MUF significantly reduced transfusion of coagulation factors (5.4 +/- 5.0 mL/kg versus control: 39.9 +/- 25.8 mL/kg, p = 0.007), and duration of ventilatory support (59.3 +/- 36.2 hours versus 242.1 +/- 143.1 hours, p = 0.0009). In patients with prolonged CPB (>120 minutes), MUF significantly reduced the duration of ventilatory support (44.7 +/- 37.0 hours versus 128.7 +/- 133.4 hours, p = 0.002). No significant differences were observed between MUF and control patients for any parameter in the presence of ventricular septal defect without pulmonary hypertension, tetralogy of Fallot, or aortic stenosis. CONCLUSIONS Modified ultrafiltration after CPB is safe and decreases the need for homologous blood transfusion, the duration of ventilatory support, and chest tube placement in selected patients with complex congenital heart disease. The optimal use of MUF includes patients with preoperative pulmonary hypertension, neonates, and patients who require prolonged CPB.

Dilutional And Modified Ultrafiltration Reduces Pulmonary Hypertension After Operations For Congenital Heart Disease: A Prospective Randomized Study

OBJECTIVE A prospective randomized study was performed to test whether removal of endothelin-1, by ultrafiltration techniques, will reduce pulmonary hypertension after operations for congenital heart disease. METHODS Twenty-four patients with pulmonary hypertension (systolic pulmonary/systemic arterial pressure ratio > 60%) undergoing cardiac operations were randomized into a control group (n = 12) having conventional ultrafiltration and an experimental group (n = 12) undergoing dilutional ultrafiltration during and modified ultrafiltration after cardiopulmonary bypass. Plasma endothelin-1, nitric oxide metabolites, and cyclic guanosine monophosphate were assayed before bypass, 10 minutes into bypass, after bypass, and 0, 3, 6, and 12 hours after the operation in both groups, as well as in the ultrafiltrates and after modified ultrafiltration in the experimental group. Both groups received alpha-blockers (chlorpromazine and/or prazosin) postoperatively using the same guidelines. RESULTS The ultrafiltrates contained significant amounts of endothelin-1 (1.81 +/- 0.86 pg/ml, dilutional, and 6.44 +/- 1.82 pg/ml, modified ultrafiltrate). Endothelin-1 and the pulmonary/systemic pressure ratio were significantly lower in experimental compared with control patients. Nitric oxide metabolites and cyclic guanosine monophosphate increased similarly in both groups for 12 hours after the operation (p = not significant). Three of 12 control patients (25%) but no experimental patients had pulmonary hypertensive crises (p = 0.07). The experimental patients required significantly less ventilatory support (67 +/- 47 hours vs 178 +/- 139 hours for control patients, p = 0.048). CONCLUSIONS Dilutional and modified ultrafiltration reduce endothelin-1 and the pulmonary/systemic pressure ratio postoperatively and may become an important adjunct for preventing pulmonary hypertension after operations for congenital heart disease in high-risk patients.

PTFE monocusp valve reconstruction of the right ventricular outflow tract

BACKGROUND Transannular patching of right ventricular outflow tract obstructive (RVOTO) defects results in pulmonary insufficiency (PI). Biologic monocusp valves (MO) can prevent acute PI but are prone to early degeneration and progressive regurgitation. Polytetrafluoroethylene (PTFE, 0.1 mm) MO leaflets demonstrated favorable characteristics in animal studies, and the technique was applied to a variety of RVOTO anomalies. METHODS From June 1990 through June 1999, 158 patients underwent either PTFE MO RVOT reconstruction (n = 115 patients; 120 implants) or nonvalved transannular repair (TA) repairs (n = 43 patients; 5 subsequent MO implants) at our institution. Standard MO construction techniques and TA repairs were utilized. Intraoperative, postoperative, and echocardiographic data with a mean interval of 2.6 years (range 6 months to 8 years) were used in retrospective fashion to compare clinical outcomes. In addition, PTFE monocusp valves beyond 6 months postimplant underwent echocardiographic analysis of MO function and durability. RESULTS There were 4 early (MO-3, TA-1) and no late deaths. Overall, perioperative complications were not significantly different between MO and TA groups, nor were total hospitalization days (9.1 versus 10.7, p = 0.24). However, a significant difference in intensive care unit (ICU) utilization (3.6 versus 5.8 days, p = 0.03) favored MO patients. Patients with tetralogy of Fallot (TOF) and ventricular septal defect/pulmonary atresia (VSD/PA) undergoing the MO implant demonstrated a trend toward improved survival (p = 0.08) when compared to TA repairs. Intraoperative PI was graded mild in the MO group and moderate-severe in the TA group (p = 0.003). Progressive MO regurgitation occurred (mild-moderate) but remained significantly less than the transannular patch repairs (p < 0.05). CONCLUSIONS Utilization of a PTFE MO valve prevents short-term and significantly reduces midterm PI. It is inexpensive, easy to construct, and demonstrates no evidence of stenosis, calcification, or embolization. Despite longer cardiopulmonary bypass and ischemic times, it reduces ICU stay and, in both TOF and VSD/PA patients, decreases operative morbidity and mortality.

Surgery for aortic stenosis in children: a 40-year experience

BACKGROUND Aortic stenosis (AS) is encountered in approximately 5% of children with heart disease. The indications for surgery and the surgical techniques for AS are well established. This report focuses on the early and long-term outcomes in children with AS over a 40-year period. METHODS Included in this study were 508 patients ranging in ages from 1 day to 19 years, who were operated on for AS between 1960 and 2002. Eighty-one percent (414 of 508) of the patients had left ventricular outflow tract obstruction (LVOTO) at a single level: 40 supravalvar, 242 valvar (critical AS in 85 neonates and young infants and in 157 older children), and 132 subvalvar. Nineteen percent (94 of 508) of the patients had LVOTO at more than one level. Associated congenital cardiac defects were found in 32% of the patients. RESULTS The overall hospital mortality rate was 8% (40/508) with neonates with critical AS having the highest mortality (33%). The late mortality was 4% for the entire group. Follow-up was 95% complete. The mean follow-up was 8.5 +/- 7.1 years. In the subgroup with multilevel LVOTO (n = 94), the average intraoperative peak systolic left ventricular-aortic gradient decreased from 80 to 22 mm Hg after repair but increased progressively to 74 +/- 36 mm Hg (p < 0.05) before reintervention was required. One hundred twenty-one patients (24%) underwent 151 reoperations for recurrent or residual LVOTO or aortic regurgitation. Actuarial curves predict a 20-year survival of 88% and 62% freedom from reoperation for all patients with AS. Symptomatic improvement in survivors was excellent (90% New York Heart Association class I). CONCLUSIONS Surgical relief of LVOTO in infants and children can be accomplished with low mortality and morbidity. Neonates with critical AS have significantly higher mortality and morbidity due to their complex anatomy and their critical presentation that affects outcome. Aortic valvotomy delays valve replacement in a significant percentage of children. The Ross procedure and mechanical aortic valve replacements have had a low mortality and morbidity in our series. Valve replacement will eventually be required in most children presenting with valvar AS and multilevel LVOTO while repair of discrete subaortic stenosis and supravalvar AS may not require reoperation in most patients. Children with LVOTO should have lifetime follow-up.

Surgical repair of congenital supravalvular aortic stenosis in children.

OBJECTIVE Supravalvular aortic stenosis (SVAS) is an uncommon congenital cardiac anomaly characterized by varying degrees of left ventricular outflow tract obstruction beginning distal to the aortic valve. METHODS Between March 1962 and December 2000, 101 consecutive patients underwent surgical correction for congenital SVAS at Riley Childrens Hospital. There were 61 male (60%) and 40 female (40%) ranging in age from 3 month to 17 years (medium age, 6.1 years). Fourteen patients (14%) had Williams syndrome. Preoperatively, 11 patients were in New York Heart Association (NYHA) functional class I, 55 in class II, 28 in class III, and seven in class IV. Of the 101 patients, 73 (72%) had localized type SVAS and 28 (28%) diffuse type SVAS. RESULTS Those with localized SVAS were successfully treated with patch aortoplasty, whereas those with diffuse SVAS required either an apical aortic conduit or extensive endarterectomy with patch aortoplasty. The overall mean pressure gradient was reduced to 21 mmHg (P<0.001) in the early postoperative period. There were one early death (<30 days postoperatively) (1%), two (2%) late deaths, and 14 patients (14%) underwent one or two additional operation (n=17) in a follow-up period ranging from 6 months to 30 years (medium 9.4 years). Postoperatively, there were 72 patients (73%) in NYHA functional class I and 26 (27%) in class II. Overall survival including operative mortality was 98% at 10 years, 97% at 20 and at 30 years. CONCLUSION Good surgical outcome of congenital SVAS can be achieved with the appropriate method of treatment in patients with both localized and diffuse SVAS.

Truncus arteriosus repair: Outcomes, risk factors, reoperation and management

OBJECTIVES Truncus arteriosus (TA) continues to be associated with significant morbidity and mortality, but there have been clinically significant improvements with early repair. METHODS Sixty patients underwent physiological correction of TA between November 1978 and January 2000. The average age was 76 days (range, 3 days--20 months). Associated cardiac anomalies were frequently encountered, the most common being severe truncal valve regurgitation (n=7), interrupted aortic arch (n=6), coronary artery anomalies (n=6), non-confluent pulmonary arteries (n=4), and total anomalous pulmonary venous return (n=1). Truncal valve replacement was performed initially or subsequently in seven patients with severe regurgitation (mechanical prostheses in six patients and a cryopreserved aortic homograft in one patient). Right ventricle--pulmonary artery continuity was established with an aortic (n=16) or pulmonary homograft (n=32) in 48 patients, a Dacron polyester porcine valved conduit in five, a non-valved polytetrafluoroethylene (PTFE) tube in three, direct anastomosis to the right ventricle with anterior patch arterioplasty in three, and a bovine jugular venous valve conduit in one patient. RESULTS There were ten hospital deaths (17%; 70% confidence limit, 7--25%). Multivariate and univariate analyses demonstrated a relationship between hospital mortality and associated cardiac anomalies. In the 43 patients without these associated cardiac anomalies, the early survival was 91% (group I). In the 17 patients with one or more of these risk factors, the survival was 71% (group II, P=0.002). There was one late death. Twenty-three patients (46%) required reoperation for right ventricular outflow tract (RVOT) obstruction at a mean follow-up time of 59.1 months. In 23 patients, the RVOT reconstruction was performed with a PTFE monocusp, and six patients had of a variety of replacement conduits inserted. Postoperatively, there were 34 (68%) patients in New York Heart Association functional class I and 16 (32%) in class II. Twenty-eight surviving patients are reported as doing well without any medication. The freedom of reoperation in the 39 hospital survivors (group I) without risk factors was 64% at 7 years; and 36% at 10 years in the 11 patients (group II) surviving with risk factors. CONCLUSIONS Associated cardiac anomalies were risk factors for death after the repair of TA. In the absence of these associated lesions, TA can be repaired with an excellent surgical outcome in the neonatal and early infancy period.

Pulmonary valve replacement: a comparison of three biological valves.

BACKGROUND We retrospectively reviewed the performance of the mosaic porcine, bovine pericardial, and homograft prostheses for pulmonary valve replacement to correct chronic pulmonary insufficiency. METHODS From January 1995 to August 2006, 82 patients (mean age, 22.7 years) underwent valve replacement with porcine (49 patients), bovine pericardial (18 patients), or pulmonary homograft (15 patients) prosthesis at a mean of 15.3 years after initial outflow tract reconstruction. Excluded were patients with extracardiac conduits, monocusp valves, or the Ross procedure. The groups were similar with respect to age, body surface area, degree of regurgitation, right ventricular dimension, right ventricular to pulmonary artery gradient, and valve size. Follow-up was longer in the homograft cohort (porcine, 20 +/- 27 months; pericardial, 42 +/- 21; homograft, 49 +/- 40; p < 0.01). RESULTS All three prostheses significantly reduce chronic pulmonary regurgitation, but late insufficiency was higher with homografts. Right ventricular dimension was significantly reduced in the stented but not the allograft cohorts. Late valve dysfunction was highest with homografts (54%), followed by porcine (19%) and pericardial valves (5.5%; p < 0.05. Functional class and mild to moderate tricuspid insufficiency significantly improved with pulmonary valve replacement. Early and late mortality was 3.6% and 1.2%, respectively. CONCLUSIONS All three prostheses performed similarly for 3 years. Pulmonary regurgitation developed more frequently in homografts albeit at a longer duration of follow-up.

Biological versus mechanical aortic valve replacement in children

BACKGROUND Aortic valve replacement in children remains challenging because of constraints imposed by available prosthetic devices. Potential risks of anticoagulation with mechanical valves and degeneration of other biological substitutes have kindled interest in the Ross procedure. This study outlines the evolution of our 27-year experience with prosthetic devices. METHODS Ninety-nine patients who underwent aortic valve replacement (January 1973 through September 2000) were included in this study. Procedures included implantation of pulmonary autograft (PA) (n = 42), aortic homograft (AH) (n = 3), mechanical valves (MV) (n = 41), and xenograft tissue valves (XG) (n = 13). RESULTS The mean follow-up times were: 3.8+/-1.3 years for PA, 3.5+/-1.5 years for AH, 7.7+/-4.7 years for MV, and 8.4+/-4.8 years for XG. There were no significant differences in perioperative outcomes among the groups (p < or = 0.05) or early deaths (2 each in the MV, AH, and PA groups). The incidence of valve-related complications and reoperations was high in the MV (n = 5), XG (n = 7), and AH (n = 1) groups as compared with the PA group (n = 3, p < 0.01). Early and late mortality for the series was 8.6% (n = 8). Overall, the reoperation rate was 20.7% (n = 18): 15.2% (5 of 33) MV, 70% (7 of 10) XG, 50% (1 of 2) AH, and 11.9% (5 of 42) for PA. The actuarial survival rate was 87.8% and 100% at 10 years for MV and XG, and 95.2% and 6.6% at 7 years for PA and AH. CONCLUSIONS Aortic valve replacement in children can be performed with acceptable mortality and good long-term results. The Ross procedure, although more complicated, has the advantage of not requiring anticoagulation therapy, can be performed in all age groups, possesses inherent growth potential, and exhibits the most normal left ventricular outflow tract hemodynamics.

Follow-up of surgical correction of aortic arch anomalies causing tracheoesophageal compression: a 38-year single institution experience

OBJECTIVE Anomalies of the aortic arch (vascular rings) are uncommon anomalies in which preferred strategies for diagnosis and treatment may vary among institutions. In this study, we report a description of our approach and review of our 38-year experience in patients surgically treated for vascular rings. METHODS A retrospective review was conducted of all patients with/without symptomatic tracheoesophageal compression secondary to anomalies of the aortic arch and great vessels diagnosed from 1970 to 2008. A total of 183 patients underwent surgical repair. Median age at the time of the operation was 5 months (range, 3 days to 30 years). Patients were classified into 5 major subtypes based on their surgical anatomy as follows: right aortic arch-left ligamentum (n = 77), double aortic arch (n = 67), aberrant (retroesophageal) right subclavian artery (n = 30), pulmonary sling (n = 8), and innominate artery compression (n = 1). Six patients (3%) had an associated Kommerell diverticulum. In patients with a double aortic arch, 82% had a dominant right arch and 18% had a dominant left arch. Preoperatively, 80 patients (44%) had stridor, and 86 patients (47%) had recurrent upper respiratory tract infection. RESULTS Associated cardiac diagnosis were present in 54 (30%) of 183 of all patients with vascular rings. Left thoracotomy was a common operative approach in all patients except pulmonary artery sling patients where a median sternotomy was the preferred approach. There were 3 early and 5 late deaths (all patients had complex cardiac anomalies) with a median follow-up of 6 years. Overall survival was 96% at 35 years. Postoperative complication occurred in 3 patients (2%) as follows: tracheostomy because of severe distal tracheal compression (n = 2) and left true vocal cord paralysis (n = 1). None of the patients showed any evidence of recurrent vascular ring anomalies at last follow-up. Of the children, 75% (135/180) were free from compressive symptoms within 1 year of the operation. CONCLUSIONS Vascular anomalies with/without tracheoesophageal compression present symptomatically in a variety of ways, and noninvasive methods are used to identify the specific lesion and associated cardiac defects. Surgical repair is associated with low or no mortality in patients with uncomplicated complex of vascular anomalies.

Donor cardiac troponin T: a marker to predict heart transplant rejection

BACKGROUND Noninvasive methodologies have shown poor sensitivity in predicting rejection when compared to serial endomyocardial biopsies. We studied the potential role of donor blood troponin T (Tn-T) as a marker for predicting heart transplant rejection. METHODS Blood cardiac Tn-T was measured from 16 heart donors. Transplant rejection and cardiac function in the recipients were monitored for 1 year. RESULTS When data were analyzed based on donor blood Tn-T levels, 6 patients who received hearts from donors with low Tn-T (<0.45+/-0.1 ng/mL) showed no rejection, and patients whose hearts came from donors with higher Tn-T (6.01+/-0.81 ng/mL) developed episodes of high-grade rejection (3A) within 38.5+/-2.1 days after transplantation. Eight patients who received hearts from donors with intermediate levels of Tn-T (3.57+/-0.55 ng/mL) showed mild rejection (grade 1). All recipients had qualitatively normal left ventricular systolic function by serial echocardiography. The mean donor ischemic time was 169+/-47 minutes. CONCLUSIONS The quality of the donor heart is an important prognostic factor in heart transplantation. It may be possible to identify severely damaged donor organs before transplantation and avoid their use or to develop more aggressive strategies for reducing recurrent acute rejection episodes in high-risk patients.