Aortic aneurysms remain a significant source of morbidity and mortality after use of Dacron(®) patch aortoplasty to repair coarctation of the aorta: results from a single center.

Aortic aneurysm formation after coarctation repair is a serious and life-threatening complication. Repairs using synthetic materials such as Dacron(®) may carry the highest risk of aneurysm formation and rupture. The authors sought to determine the prevalence of aneurysm formation in patients who previously underwent coarctation repair using Dacron(®) patch aortoplasty at their institution. Between 1977 and 1994, 63 patients underwent isolated coarctation repair using Dacron(®) patch aortoplasty. Aneurysms were defined as an aortic dimension 1.5 times that of the aorta at the level of the diaphragm as shown by angiography, computed tomography (CT) scan, or magnetic resonance imaging (MRI). Of 61 early survivors, 29 (47 %) experienced an aneurysm in the area of previous repair. Nine patients (31 %) had spontaneous rupture of the aneurysm, which caused death in seven cases. Elective or emergent aneurysm repair was performed for 20 patients without complication, and 2 patients are being monitored at this writing. The mean interval from patch placement to aneurysm repair was 15 years (range, 4-27 years). Overall freedom from the development of an aortic aneurysm was 97 % at 5 years, 90 % at 10 years, 69 % at 20 years, and 42 % at 25 years. After repair of coarctation using Dacron(®) patch aortoplasty, the risk for aneurysm formation in the area of repair and death from rupture is extremely high. Therefore, in accordance with the 2008 American Heart Association/American College of Cardiology (AHA/ACC) guidelines, all patients with repaired aortic coarctation should undergo either CT or MRI imaging at least every 5 years to assess for aortic aneurysm formation. More frequent imaging should be obtained for patients previously repaired with Dacron(®) patch aortoplasty.

The Supported vs Unsupported Ross in Pediatric Patients: Neoaortic Root and Ventricular Function.

BACKGROUND: The supported Ross is used to mitigate the neoaortic root dilation that has been described with the unsupported Ross. There is limited literature assessing the efficacy of the supported Ross in young patients. In this study, the fate of the neoaortic root was compared in the supported and unsupported Ross procedure in adolescent patients. METHODS: A retrospective review was performed of patients who underwent the Ross procedure between 1996 and 2019. An analysis was conducted of patients aged 10 to 18 years who underwent the supported and unsupported Ross operation, without a Konno enlargement, to assess for longitudinal echocardiographic changes. Given differences in follow-up time, both regression analysis and Mann-Whitney nonparametric tests were used to correct for time from discharge to most recent follow-up. RESULTS: The median follow-up time for supported and unsupported Ross patients without a Konno enlargement was 2.90 years (0.21-13.03 years) and 12.13 years (2.63-19.47 years), respectively. Unsupported Ross patients experienced a higher rate of change per year in the aortic annulus (P = .003 and P = .014) and aortic sinus (P = .002 and P = .002) diameters, respectively. There was no significant difference in the rate of change of end-diastolic left ventricular internal diameter (P = .703 and P = .92) and aortic insufficiency (P = .687 and P = .215) between the supported and unsupported Ross patients. CONCLUSIONS: Progressive dilation of the neoaortic root in unsupported Ross patients is significantly mitigated with the supported Ross with excellent stability. The supported Ross is safe and effective and may play an increasing role in the management of children with aortic disease.

Unobstructive total anomalous pulmonary venous return: impact of early elective repair on the need for prolonged mechanical ventilatory support.

Optimal timing for elective repair of total anomalous pulmonary venous return (TAPVR) in the case of an unobstructed anomalous pathway is unclear. All infants with a diagnosis of TAPVR as an isolated lesion who underwent surgical repair at Children's Hospital of Wisconsin from 1991 to 2007 were reviewed to assess location of drainage, presence of obstruction, age at presentation, age at surgery, death, need for extracorporeal membrane oxygenation (ECMO), length of hospital stay, length of mechanical ventilation (MV), and late pulmonary venous obstruction. A total of 65 patients were identified: 38 (59%) with supracardiac drainage, 10 (15%) with cardiac drainage, 11 (17%) with infracardiac drainage, and 6 (9%) with mixed drainage. For 39 (60%) of the 65 patients, obstruction was identified preoperatively. Three early and five late deaths occurred after surgery (12%), all involving patients with preoperative obstruction. Most of the late deaths (80%) involved patients who experienced recurrent obstruction. Of the 65 patients, 26 (40%) had no obstruction preoperatively, and none died, required ECMO support, or experienced late obstruction. For the 26 patients without obstruction, the timing of surgery was elective at the discretion of the supervising cardiologist. Among these 26 patients, 15 had surgery less than 10 days after presentation (median age, 18 days), and 53% of these 15 patients (8/15) had MV less than 5 days. In contrast, all 11 patients who had elective surgery more than 10 days after presentation (median age, 56 days) required MV for more than 5 days (p = 0.007). Isolated TAPVR appears to be at the highest risk for death and late postoperative obstruction when obstruction is present preoperatively. Patients with unobstructive TAPVR do very well, but potential morbidity related to prolonged MV appears to be significantly reduced by early elective surgery.

Complex atrioventricular canal.

Complex forms of atrioventricular (AV) canal (C) such as; AVC with left ventricular outflow tract obstruction, tetralogy of Fallot with complete AVC, double orifice left AV valve, unbalanced complete AVC, and single ventricle patients with common AVC valve require careful preoperative planning and special techniques. This review will explore these technical modifications and outcomes for repair of complex variants of AVC. Optimal results will be achieved using an individually tailored approach that is guided by careful evaluation of the preoperative studies, precise operative technique, and intraoperative assessment of the reconstructed AV valve, as well as a willingness to re-intervene should the postoperative course not proceed as anticipated.

The double patch repair for complete atrioventricularis communis.

This article is a review of our experience with the two-patch repair of complete atrioventricularis communis. From October 1988 through December 2005, 222 infants and children underwent surgery. There were six early (2.7%) and six late (2.7%) deaths. Reoperation was required in 22 patients (10%) for residual or recurrent mitral regurgitation or stenosis, subaortic stenosis, repair of a ventricular septal defect with or without pulmonary stenosis, placement of a right heart valved conduit, and/or placement of a permanent cardiac pacemaker. All patients survived second operations and no child required early or late mitral valve replacement. The two-patch repair is a reliable surgical technique resulting in low mortality and a low need for reoperation.

Activation of protein kinases in chronically hypoxic infant human and rabbit hearts: role in cardioprotection.

BACKGROUND: Many infants who undergo heart surgery have a congenital cyanotic defect in which the heart is chronically perfused with hypoxic blood. However, the signaling pathways by which infant hearts adapt to chronic hypoxia and resist subsequent surgical ischemia is unknown. METHODS AND RESULTS: We determined the activation and translocation of protein kinase C (PKC) isoforms and mitogen activated protein kinases (MAP kinases) in 15 infants with cyanotic (SaO2<85%) or acyanotic (SaO2>95%) heart defects undergoing surgical repair and in 80 rabbits raised from birth in a hypoxic (SaO2<85%) or normoxic (SaO2>95%) environment. Tissues from infant human and rabbit hearts were processed for Western and in vitro kinase analysis. In human infants with cyanotic heart defects, PKCepsilon, p38 MAP kinase, and JUN kinase but not p42/44 MAP kinase were activated and translocated from the cytosolic to the particulate fraction compared with acyanotic heart defects. In rabbit infants there was a parallel response for PKCepsilon, p38 MAP kinase, and JUN kinase similar to humans. In infant rabbit hearts inhibition of PKCepsilon with chelerythrine, p38 MAP kinase, with SB203580 and JUN kinase with curcumin abolished the cardioprotective effects of chronic hypoxia but had no effects on normoxic hearts. CONCLUSIONS: Infant human and rabbit hearts adapt to chronic hypoxia through activation of PKCepsilon, p38 MAP kinase, and JUN kinase signal transduction pathways. These pathways may be responsible for cardioprotection in the chronically hypoxic infant rabbit heart.

Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients.

BACKGROUND: Outcome of stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS) has improved coincident with application of treatment strategies including continuous superior vena cava oximetry (SvO2), phenoxybenzamine (POB), strategies to minimize the duration of deep hypothermic circulatory arrest (DHCA) and efforts to ameliorate the inflammatory response to cardiopulmonary bypass (CPB) using aprotinin and modified ultrafiltration. METHODS AND RESULTS: Analysis of a consecutive series of 115 patients undergoing S1P was done to identify the risk factors for mortality and the impact of new treatment strategies. For the current era, July 1996 to October 2001, hospital survival was 93% (75/81) compared with 53% (18/34) for the time period, January 1992 to June 1996, P<0.001. Survival to stage 2 palliation (S2P) was also significantly improved in the current era, 81% (66/81) versus 44% (15/34), P<0.01. Anti-inflammatory treatment strategies demonstrated improved survival by univariate analysis (P<0.001). Multivariate analysis identified continuous SvO2 monitoring as a factor favoring S1P survival (P=0.02) and use of POB as a factor favoring survival to S2P (P=0.003). In the current era shorter duration of DHCA was associated with improved survival to S2P (P=0.02). CONCLUSIONS: Improved survival following S1P can be achieved with strategies that allow for early identification of decreased systemic output and the use of afterload reduction to stabilize systemic vascular resistance and therefore the pulmonary to systemic flow ratio. Strategies to ameliorate the inflammatory response to CPB may decrease the degree and duration of postoperative support. Strategies to minimize duration of DHCA may improve intermediate survival and merit additional studies.

Safety of aprotinin use and re-use in pediatric cardiothoracic surgery.

BACKGROUND: Hypersensitivity reactions to aprotinin have been reported in adult cardiac surgical patients undergoing initial and re-exposure to the medication. This study describes the incidence and impact of aprotinin hypersensitivity reactions in children undergoing cardiothoracic surgery. METHODS AND RESULTS: In this retrospective review of our entire experience with aprotinin (n=865), 681 first exposures, 150 second exposures, and 34 third or higher exposures were examined. Reactions were classified as mild (generalized cutaneous erythema, Type A) or severe (unexplained cardiopulmonary instability after aprotinin exposure, Type B). Records of patients sustaining a reaction were reviewed to assess the impact of the reaction on outcome and to survey reaction management strategies. Reactions occurred in 7 of 681 first exposures (1.0%), of which 2 were Type A and 5 were Type B. In second exposures, there were reactions in 2 of 150 (1.3%), of which both were Type B. In 34 third or higher exposures, there was only 1 reaction (2.9%), which was Type B. Reactions were no more likely on second, third, or higher exposure than on initial exposure. Skin testing had a negative predictive value of 98.9% and a positive predictive value of 20%. Anti-aprotinin IgE was undetectable in 7 of 8 reactor cases tested. No adverse sequelae were attributed to aprotinin reaction. CONCLUSIONS: The risk of hypersensitivity reactions to aprotinin is low in children undergoing cardiothoracic surgery, even with multiple exposures to the medication. Reactions are more likely with re-exposure, and risk increases with multiple exposures. Neither skin testing nor assays for IgE identified reactors.

Complex aortic valve repair as a durable and effective alternative to valve replacement in children with aortic valve disease.

OBJECTIVE: This study was undertaken to determine the utility of aortic valve repair in children. METHODS: A retrospective analysis was conducted on aortic valve surgery from 1973 to 2004 at Children's Hospital of Wisconsin. RESULTS: Procedures were classified as simple repairs (blunt valvotomy, commissurotomy with or without thinning, n = 147), repair of aortic insufficiency with ventricular septal defect (n = 22), complex repairs (any combination of additional procedures including suspension of prolapsed leaflets, leaflet extensions, repair of torn or perforated leaflets, annuloplasty, reduction of sinus of Valsalva plasty, and concomitant repair of supravalvular or subvalvular stenosis, n = 57), and replacements (n = 57, 20 mechanical, 2 porcine, and 35 human valves). Freedoms from reintervention for simple repairs and repair of aortic insufficiency with ventricular septal defect at 10 years were 86% +/- 5% and 93.3% +/- 6%, respectively. For complex valve repair, freedoms from reintervention at 1, 5, and 10 years were 94% +/- 3%, 85% +/- 6%, and 44% +/- 15%, versus 96% +/- 3%, 77% +/- 9%, and 77% +/- 9% for valve replacement ( P = .3). At intermediate follow-up, patients with complex valve repair had a residual gradient of 20 +/- 21 mm Hg, and 94% were free of severe aortic insufficiency. Residual aortic stenosis ( P < .05) but not the preoperative diagnosis of combined aortic stenosis and insufficiency predicted the need for reintervention. CONCLUSION: Freedom from reintervention after complex valve repairs was not different from that after valve replacement, with acceptable residual aortic stenosis and insufficiency. Simple repairs and repair of aortic insufficiency with ventricular septal defect yielded excellent long-term freedom from reintervention.

Aortic valve repair.

Aortic valve replacement options are limited in children, and all of them have disadvantages. Aortic valve repair techniques have evolved slowly and have not gained wide acceptance; however, large series using a variety of techniques demonstrate that valve repair is possible with excellent early hemodynamics and satisfactory intermediate durability. The results of aortic valve repair at the Children's Hospital of Wisconsin are presented. Simple repairs (blunt valvotomy, commissurotomy, or commissurotomy with leaflet thinning) directed at congenital aortic stenosis resulted in 86% +/- 5% freedom from reintervention at 10 years. Repair of aortic insufficiency with ventricular septal defect (VSD) resulted in 93.3% +/- 6% freedom from reoperation at 10 years. Complex repairs included a combination of techniques and yielded 5-year freedom from reintervention of 83% +/- 7% compared with 73% +/- 11% for patients undergoing aortic valve replacement (P = .62). Aortic valve repair provides an alternative to aortic valve replacement in selected patients. The utility of aortic valve repair and aortic valve replacement must be measured not only in freedom from reintervention but also in regression of left ventricular mass and exercise testing. Improvement in outcome depends on better patient selection and suitable bioprosthetic materials.

Surgical therapy for sudden cardiac death in children.

Sudden cardiac death (SCD) in children is the result of multiple etiologies and treatment (prophylaxis) must be tailored accordingly. In children who do not have congenital heart disease, surgical therapy of SCD typically consists of implantation of an internal defibrillator, with specific attention to the small size of the patient. In children who have unrepaired congenital heart disease, therapy of SCD is primarily repair of the congenital anomaly. In children or young adults who have previously undergone surgery for congenital heart disease, SCD therapy consists of repair of any residual or acquired structural defect, often in combination with antiarrhythmia surgery or defibrillator implantation.

Mixed venous oxygen saturation monitoring after stage 1 palliation for hypoplastic left heart syndrome.

BACKGROUND: Staged palliation for hypoplastic left heart syndrome has been marked by high early mortality due to the limited cardiac output of the postischemic single right ventricle combined with the inefficiency and volatility of parallel circulation. METHODS: Since July 1996, we have performed stage 1 palliation (S1P) in 178 patients. Within this group is a consecutive cohort of 116 patients with true hypoplastic left heart syndrome that underwent S1P with a modified Blalock-Taussig shunt. A prospective database containing postoperative hemodynamic data was maintained on all patients. Studied were the incidence of organ failure, extracorporeal membrane oxygenation (ECMO), and mortality, as well as the relationship between these outcomes and postoperative hemodynamics. RESULTS: Hospital survival for this cohort was 93% (108/116). Patients who died after S1P had a lower superior vena cava oxygen saturation (SVO2) level compared with survivors (53.1% +/-10.6% versus 59.3% +/-9.2%, p = 0.034). Renal failure developed in 2 (1.7%) of the 116 patients, necrotizing enterocolitis developed in 1 (0.9%), and 5 (4.3%) had clinical seizures. ECMO support was instituted in 12 patients (10.3%). The SVO2 level was lower in patients requiring ECMO (54.0% +/- 9.7% versus 59.9% +/- 9.2%, p = 0.031). CONCLUSIONS: Goal-directed therapy with SVO2 as an indicator of systemic oxygen delivery is associated with excellent early survival and a low incidence of organ failure after S1P. Inability to optimize SVO2 in the early postoperative period is associated with an increased risk of organ failure, ECMO, and death.

SURGICAL MANAGEMENT OF A NEONATE WITH INTERRUPTED AORTIC ARCH, TRANSPOSITION OF THE GREAT ARTERIES, AND TRICUSPID ATRESIA.

A critically ill infant presented to our Center with congestive heart failure due to Type A interrupted aortic arch, D-transposition of the great arteries, tricuspid atresia, a large ventricular septal defect, and a closing ductus arteriosus. Partially corrective surgery including aortic arch reconstruction, ductal division, and pulmonary artery banding was successful. Future total correction is planned.

USE OF AN EXTRACARDIAC CONDUIT IN THE REPAIR OF l-TRANSPOSITION WITH l-LOOPING ASSOCIATED WITH SEVERE SUBVALVULAR PULMONIC STENOSIS AND A VENTRICULAR SEPTAL DEFECT.

Total correction was performed in a child with l-transposition of the great arteries, severe subpulmonic stenosis, and a ventricular septal defect. The subpulmonic obstruction was bypassed with an extra-cardiac valved conduit. This alternate method of relieving ventricular outflow obstruction should be considered when conventional techniques cannot be employed because of complex intracardiac anatomy. Proper placement of the pulmonary ventriculotomy is important in order to avoid injury to coronary arteries on the upper and lower ventricular wall and to papillary muscles in the mid-portion of the ventricle.

Use of activated clotting time for monitoring anticoagulation during cardiopulmonary bypass in infants and children with congenital heart disease.

The use of a fixed dosage schedule was compared with the use of activated clotting time (ACT) for determining heparin and protamine dosages during and after cardiopulmonary bypass disease. Use of the ACT resulted in a statistically significant increase in heparin dosage and a statistically significant reduction of postoperative blood loss. With ACT use, chest tubes were retained for a shorter period of time, and the incidence of serious postoperative hemorrhage was reduced from 44% to 18%. These results confirm the superiority of the ACT method for monitoring intraoperative anticoagulation in pediatric patients with congenital heart disease.

Cellular redistribution of inducible Hsp70 protein in the human and rabbit heart in response to the stress of chronic hypoxia: role of protein kinases,.

Many infants who undergo cardiac surgery have a congenital cyanotic defect where the heart is chronically perfused with hypoxemic blood. Infant hearts adapt to chronic hypoxemia by activation of intracellular protein kinase signal transduction pathways. However, the involvement of heat shock protein 70 in adaptation to chronic hypoxemia and its role in protein kinase signaling pathways is unknown. We determined expression of message and subcellular protein distribution for inducible (Hsp70i) and constitutive heat shock protein 70 (Hsc70) in chronically hypoxic and normoxic infant human and rabbit hearts and their relationship to protein kinases. In chronically hypoxic human and rabbit hearts message levels for Hsp70i were elevated 4- to 5-fold compared with normoxic hearts, Hsp70i protein was redistributed from the particulate to the cytosolic fraction. In normoxic infants Hsp70i protein was distributed almost equally between the cytosolic and particulate fractions. Hsc70 message and subcellular distribution of Hsc70 protein were unaffected by chronic hypoxia. We then determined if protein kinases influence Hsp70i protein subcellular distribution. In rabbit hearts SB203580 and chelerythrine reduced Hsp70i message levels, whereas SB203580, chelerythrine, and curcumin reversed the subcellular redistribution of Hsp70i protein caused by chronic hypoxia, with no effect in normoxic hearts, indicating regulation of Hsp70i message and subcellular distribution of Hsp70i protein in chronically hypoxic rabbit hearts is influenced by protein kinase C and mitogen-activated protein kinases, specifically p38 MAPK and JNK. We conclude the Hsp70 signal transduction pathway plays an important role in adaptation of infant human and rabbit hearts to chronic hypoxemia.