Glen S. Van Arsdell

Evolving strategies and improving outcomes of the modified Norwood procedure: a 10-year single-institution experience

BACKGROUND This study reviews our 10-year experience with the modified Norwood procedure to determine its early and midterm outcomes. The focus is on the impact of evolving management strategies and accumulated institutional experience. METHODS A modified Norwood operation was performed in 171 infants over a 10-year period. Sixty-eight percent of the infants were male, the median age at operation was 6 days (range 1 to 175 days), and the median weight was 3.3 kg (range 1.7 to 4.8 kg). The 10-year period was divided into three eras: era I; 1990 through 1993; era II; 1994 through 1997; and era III; 1998 into 2000. Outcomes and risk factors for mortality were sought. RESULTS Hypoplastic left heart syndrome or a variant was the primary diagnosis in 118 infants (69%). The overall 5-year survival rate was 43%. Multivariate analysis revealed that only need of preoperative ventilatory support, earlier date of operation, and lower weight at operation were significant independent predictors of increased time-related mortality. Morphologic features such as a diagnosis other than hypoplastic left heart syndrome, ascending aortic size, and noncardiac anomalies were not significantly associated with an increased risk of death. The hospital survival rate for stage-one palliation in era III was 82%, significantly better than that in the preceding eras (p < 0.001). Attrition between stages one and two accounted for a 15% mortality rate among hospital survivors. CONCLUSIONS With increasing experience and improvements in perioperative care and surgical technique, good outcomes can be expected for the first-stage modified Norwood procedure. Greater monitoring of patients in the interstage period may reduce interval mortality and improve overall survival.

Factors Associated With Mortality and Reoperation in 377 Children With Total Anomalous Pulmonary Venous Connection

Background— We sought to determine era-specific changes in the incidence of mortality and reoperation in children with total anomalous pulmonary venous connection. Methods and Results— We reviewed the records of 377 children presenting from 1946 to 2005 with total anomalous pulmonary venous connection. Multivariable parametric regression models determined the incidence and risk factors for death and reoperation after repair. Pulmonary venous connection was supracardiac in 44%, infracardiac in 26%, cardiac in 21%, and mixed in 9%. Pulmonary venous obstruction was present in 48% at presentation, most frequently with infracardiac connection type (P<0.001). In total, 327 patients were repaired (median age, 1.7 months). Overall survival from repair was 65±6% at 14 years, with a current survival of 97%. Significant (P<0.01) incremental risk factors for postrepair death were cardiac connection type, earlier operation year, younger age at repair, use of epinephrine postoperatively, and postoperative pulmonary venous obstruction. More recent operation year was associated with younger age at repair (P<0.001), decreased use of deep hypothermic circulatory arrest (P<0.001), and use of specific drugs postoperatively (P<0.001). Risk-adjusted estimated 1-year survival for a patient repaired at birth with unfavorable morphology in 2005 is 37% (95% CI, 8 to 80) compared with 96% (95% CI, 91 to 99) for a patient with favorable morphology repaired at 1 year of age. Freedom from reoperation was 82±6% at 11 years after repair, with increased risk associated with mixed connection type (P=0.04) and postoperative pulmonary venous obstruction (P<0.001). Conclusions— Mortality after total anomalous pulmonary venous connection repair has decreased but remains highest in young patients and in those with cardiac connection type or pulmonary venous obstruction. Unfavorable anatomic characteristics remain important determinants of postrepair survival despite improved perioperative care.

Cardiac outcomes in young adult survivors of the arterial switch operation for transposition of the great arteries.

OBJECTIVES We sought to determine cardiac outcomes in young adults with complete transposition of the great arteries (TGA) after the arterial switch operation (ASO). BACKGROUND Although cardiac outcomes in the pediatric population with TGA after ASO have been well described, outcomes in the adult population have not to our knowledge been studied. METHODS We determined late survival in all operative survivors with TGA after ASO performed before 1991 at our local pediatric referring hospital. In the subset of adults (n = 65) followed in our adult congenital cardiac clinic, we examined cardiac outcomes in adulthood. RESULTS Survival of the 132 infants discharged from hospital after ASO was 97% (70% confidence interval [CI]: 95.0% to 98.1%) at 20 years. In the 65 patients (mean age 21 +/- 3 years, 62% male) followed at our institution, 17% (11 of 65) had at least 1 clinically significant cardiac lesion, including ventricular dysfunction, valvular dysfunction, or arrhythmias. Residual lesions were more common in those who had had cardiac reinterventions in childhood (odds ratio: 10.7, 95% CI: 2.1 to 55). In adulthood, 5 patients (8%) had arrhythmia requiring treatment and 7 patients (11%) required reinterventions (5 reoperations and 2 pacemaker implantations). Intervention for aortic valve regurgitation and aortic root dilation were not observed. Exercise capacity was reduced in most adults (82%) after ASO. CONCLUSIONS Although most adults after ASO are well, and few have residual defects, there are subgroups, particularly those who needed further cardiac intervention in childhood, who are at higher risk for ventricular and valve dysfunction and arrhythmias.

Risk, Clinical Features, and Outcomes of Thrombosis Associated With Pediatric Cardiac Surgery

Background— Thrombosis, usually considered a serious but rare complication of pediatric cardiac surgery, has not been a major clinical and/or research focus in the past. Methods and Results— We noted 444 thrombi (66% occlusive, 60% symptomatic) in 171 of 1542 surgeries (11%). Factors associated with increased odds of thrombosis were age <31 days (odds ratio [OR], 2.0; P=0.002), baseline oxygen saturation <85% (OR, 2.0; P=0.001), previous thrombosis (OR, 2.6; P=0.001), heart transplantation (OR, 4.1; P<0.001), use of deep hypothermic circulatory arrest (OR, 1.9 P=0.01), longer cumulative time with central lines (OR, 1.2 per 5-day equivalent; P<0.001), and postoperative use of extracorporeal support (OR, 5.2; P<0.001). Serious complications of thrombosis occurred with 64 of 444 thrombi (14%) in 47 of 171 patients (28%), and were associated with thrombus location (intrathoracic, 45%; extrathoracic arterial, 19%; extrathoracic venous, 8%; P<0.001), symptomatic thrombi (OR, 8.0; P=0.02), and partially/fully occluding thrombi (OR, 14.3; P=0.001); indwelling access line in vessel (versus no access line) was associated with lower risk of serious complications (OR, 0.4; P=0.05). Thrombosis was associated with longer intensive care unit (+10.0 days; P<0.001) and hospital stay (+15.2 days; P<0.001); higher odds of cardiac arrest (OR, 4.9; P<0.001), catheter reintervention (OR, 3.3; P=0.002), and reoperation (OR, 2.5; P=0.003); and increased mortality (OR, 5.1; P<0.001). Long-term outcome assessment was possible for 316 thrombi in 129 patients. Of those, 197 (62%) had resolved at the last follow-up. Factors associated with increased odds of thrombus resolution were location (intrathoracic, 75%; extrathoracic arterial, 89%; extrathoracic venous, 60%; P<0.001), nonocclusive thrombi (OR, 2.2; P=0.01), older age at surgery (OR, 1.2 per year; P=0.04), higher white blood cell count (OR, 1.1/109 cells per 1 mL; P=0.002), and lower fibrinogen (OR, 1.4/g/L; P=0.02) after surgery. Conclusions— Thrombosis affects a high proportion of children undergoing cardiac surgery and is associated with suboptimal outcomes. Increased awareness and effective prevention and detection strategies are needed.

Outcomes and Associated Risk Factors for Aortic Valve Replacement in 160 Children A Competing-Risks Analysis

Background— We sought to define patient characteristics, outcomes, and associated risk factors after aortic valve replacement (AVR) in children. Methods and Results— Clinical records from children undergoing AVR from 1974 to 2004 at our institution were reviewed. Competing-risks methodology determined the time-related prevalence of 3 mutually exclusive end states: death, repeated replacement, and survival without subsequent AVR and their associated risk factors. Longitudinal echocardiographic data were analyzed by mixed linear-regression models. Children (n=160) underwent 198 AVRs, with 33 having >1. Competing-risks analysis predicted that 10 years from the initial AVR, 19% had died without subsequent AVR, 34% underwent a second AVR, and 47% remained alive without replacement. Risk factors for death without a second AVR included lower weight (P<0.001) and younger age at AVR (P=0.04), performance of aortic arch reconstruction together with AVR (P=0.03), and nonautograft use (P=0.03). Risk factors for a second AVR included earlier operation year (P=0.04) and implantation of a bioprosthetic or homograft valve (P=0.004). Analysis of serial echocardiographic measurements showed that pulmonary autograft use was associated with slower progression of peak aortic gradient (P=0.002), smaller left ventricular dimension (P=0.04), and decreased prevalence of aortic regurgitation (P=0.04). Conclusions— Mortality and repeated valve replacement are common after initial AVR in children, especially in younger patients and those with bioprosthetic or homograft valves. Pulmonary autograft use is associated with decreased mortality, slower gradient progression, and smaller left ventricular dimension.

Improving outcomes of the Fontan operation in children with atrial isomerism and heterotaxy syndromes

BACKGROUND The historic outcome of the Fontan procedure in children with single ventricle and heterotaxy syndrome has been poor, and in the current era it has been incompletely described. METHODS From January 1993 through April 2000, 30 patients (age range, 5.3 +/- 3.6 years) had total cavopulmonary connection for single ventricle and isomerism and heterotaxy syndrome. Right atrial isomerism and heterotaxy (n = 19) or left atrial isomerism and heterotaxy (n = 11) were associated with a morphologic right ventricle (n = 26), a common atrioventricular valve (n = 25), pulmonary atresia (n = 9) or stenosis (n = 17), anomalous pulmonary venous drainage (partial, n = 7; total, n = 11; obstructed, n = 4), and interrupted inferior vena cava (n = 13). A previous systemic to pulmonary artery shunt had been performed in 21 patients, and 3 patients had previous pulmonary artery banding. The Fontan procedure was staged in all but 3 patients at a median age of 12 months (range, 3 to 114 months). Before the Fontan procedure, atrial arrhythmia was present in 7 patients (23%). RESULTS An extracardiac conduit was constructed in 22 patients (median diameter, 20 mm; range, 16 to 27 mm), and a lateral tunnel was constructed in 4 patients. Associated procedures included pulmonary artery augmentation (n = 17), repair of anomalous pulmonary venous drainage (n = 7), and repair of a regurgitant atrioventricular valve (n = 2). The mean cardiopulmonary bypass time was 134 +/- 57 minutes. Cardioplegic cardiac arrest was used in 12 patients for a mean duration of 62 +/- 28 minutes. There were four hospital deaths (13%), three that occurred in children having concomitant repair of anomalous pulmonary venous drainage (previously undetected in one). Thirteen children (41%) developed early postoperative atrial arrhythmias, 11 of the 13 children required temporary pacing. There was one late death. Follow-up (3.4 +/- 2.7 years) was available on 24 of 25 survivors. All but 2 patients were in sinus rhythm. CONCLUSIONS Early and midterm outcomes after the Fontan procedure in this patient group improved and may be further ameliorated by detecting and repairing associated obstruction to pulmonary venous flow and performing atrioventricular valvuloplasty before the Fontan procedure.

Prevention of Early Sudden Circulatory Collapse After the Norwood Operation

Background—After modifications in our perioperative management protocol, we have observed a decrease in sudden circulatory collapse after the Norwood operation. The current study examines early outcomes after the Norwood operation in our unit in an attempt to identify variables that may have altered the risk of unexpected circulatory collapse. Methods and Results—We studied 105 consecutive neonates who underwent a Norwood operation in our institution. Our treatment protocol has changed in the past 3 years to include the use of alpha-blockade with phenoxybenzamine (POB) for systemic afterload reduction and selective cerebral perfusion. Forty-eight infants had selective cerebral perfusion. Forty-two infants received POB. Sixty patients had hypoplastic left heart syndrome. There was no difference in age, diagnosis, number of neonates with weight <2.5 kg, aortic size diameter <2 mm, highest preoperative lactate level, and shunt size indexed to body weight among patients with or without use of POB. Twenty-five infants had circulatory collapse during the first 72 hours. Twelve of them could be explained by technical issues. Thirteen others who appeared clinically stable had early sudden circulatory collapse without an apparent cause. Sixteen out of 25 neonates died. Of those with technical problems, 8 out of 12 died. Based on the hazard function, 3 incremental risk factors for early circulatory collapse were technical issue at operation (P<0.001), longer cross-clamp time (P<0.007), and no use of POB (P<0.002). For a technically successful operation, freedom from circulatory collapse at 72 hours is 95% with the use of POB versus 69% without (P<0.002). Diagnosis, aortic size, atrioventricular valve function, birth weight, age at operation, and total circulatory arrest time and were not predictive of early sudden circulatory collapse. Conclusion—Recent changes in our treatment protocol have resulted in a decrease incidence of sudden circulatory collapse after the Norwood operation. Optimal surgical technique is the most important predictor of early survival. The use of aggressive afterload reduction with POB reduced the risk of early sudden arrest.

Delayed primary repair of intrathoracic esophageal perforation: Is it safe?

The management of intrathoracic esophageal perforation with delayed diagnosis is a subject of controversy. Because of the obvious advantages of primary repair as a simple single-stage operation, this technique was preferentially used to treat 18 of 22 consecutive patients with esophageal perforation. These patients were stratified into three groups according to the time interval between perforation and repair: group A, less than 6 hours, five patients (28%); group B, 6 to 24 hours, six patients (33%); and group C, more than 24 hours, seven patients (39%). Group A patients were older (p < 0.05) and group B had fewer iatrogenic perforations (B, 17%; A, 80%; C, 57%, p < 0.1). Additional tissue was used to buttress the repair site in all three groups (A, 3/5 patients, 60%; B, 4/6 patients, 67%; C, 6/7 patients, 86%; p = not significant). In seven patients (39%), a fundic wrap was used to reinforce the site of primary repair. The outcomes of the three groups were analyzed. Group A had the lowest proportion of postoperative leaks (A, 0/4 patients, 0%; B, 4/6 patients, 67%; C, 5/6 patients, 83%; p < 0.05) and postoperative morbidity (A, 2/5 patients, 40%; B, 6/6 patients, 100%; C, 6/7 patients, 86%; p < 0.1). However the increased incidence of leak and morbidity did not lead to an increase in mortality. One death occurred in each group, with an overall mortality of 17% (A, 1/5 patients, 20%; B, 1/6 patients, 17%; C, 1/7 patients, 14%; p = not significant). We conclude that in the era of advanced intensive care capabilities, primary repair of intrathoracic esophageal perforation can be safely accomplished in most patients regardless of the time interval between perforation and operation. Leakage at the suture site is common unless primary repair is carried out without delay. Postoperative leakage, however, is usually inconsequential and does not necessarily result in an adverse outcome.

Outcomes With Ventricular Assist Device Versus Extracorporeal Membrane Oxygenation as a Bridge to Pediatric Heart Transplantation

Extracorporeal membrane oxygenation (ECMO) has long been the sole means of mechanical support for pediatric patients with end-stage cardiac failure, but has a high waitlist mortality and a reported survival to hospital discharge of less than 50%. The purpose of this study was to compare waitlist mortality and survival for ECMO versus ventricular assist device (VAD) support. A review was conducted of all patients listed for heart transplantation (HTx) since 2002 and requiring mechanical support. VAD support has been available from 2004 (Berlin Heart Excor Pediatrics). Competing risks analysis was used to model survival to one of four outcomes (HTx, death on waitlist, delisting, improvement). Thirty-six patients were on mechanical support while awaiting HTx (21 ECMO, 12 VAD, three both). Median age at listing was 1.2 years (birth-16.6 years) for ECMO and 11.3 years (0.3-14.6 years) for VAD. Diagnosis was cardiomyopathy in 33% for ECMO and 93% for VAD. Median time to HTx was 37 days (1-930) overall, 20 days (1-85) for ECMO, and 39 days (5-108) for VAD. Mechanical support was associated with increased odds of HTx (hazard ratio [HR] 2.4 [1.7-3.3], P < 0.0001) but also delisting or death waiting (HR 3.0 [1.1-7.8], P = 0.03). Waitlist mortality of 38% on ECMO was reduced to 13% with VAD use. Survival post-HTx to hospital discharge was better in the group on VAD support (92 vs. 80%). Pediatric patients requiring mechanical support as a bridge to HTx have short wait times but high waitlist mortality. Those patients who survived to be put on the Berlin Heart Excor Pediatric device based on individualized clinical decision making then had a lower waitlist mortality, a longer duration of support, and a higher survival to transplantation and hospital discharge.

Hybrid Versus Norwood Strategies for Single-Ventricle Palliation

Background— Hybrid and Norwood strategies differ substantially in terms of stage II palliative procedures. We sought to compare these strategies with an emphasis on survival and reintervention after stage II and subsequent Fontan completion. Methods and Results— Of 110 neonates with functionally single-ventricle physiology who underwent stage I palliation between 2004 and 2010, 75 (69%) infants (Norwood, n=43; hybrid, n=32) who subsequently underwent stage II palliation were studied. Survival and reintervention rates after stage II palliation, anatomic and physiologic variables at pre-Fontan assessment, and Fontan outcomes were compared between the groups. Predictors for reintervention were analyzed. Freedom from death/transplant after stage II palliation was equivalent between the groups (Norwood, 80.4% versus hybrid, 85.6% at 3 years, P=0.66). Hybrid patients had a higher pulmonary artery (PA) reintervention rate (P=0.003) and lower Nakata index at pre-Fontan evaluation (P=0.015). Aortic arch and atrioventricular valve reinterventions were not different between the groups. Ventricular end-diastolic pressure, mean PA pressure, and ventricular function were equivalent at pre-Fontan assessment. There were no deaths after Fontan completion in either group (Norwood, n=25, hybrid, n=14). Conclusions— Survival after stage II palliation and subsequent Fontan completion is equivalent between the groups. The hybrid group had a higher PA reintervention rate and smaller PA size. Both strategies achieved adequate physiology for Fontan completion. Evolution of the hybrid strategy requires refinement to provide optimal PA growth.