A multicenter study of primary graft failure after infant heart transplantation: impact of extracorporeal membrane oxygenation on outcomes.

Primary graft failure is the major cause of mortality in infant HTx. The aim of this study was to characterize the indication and outcomes of infants requiring ECMO support due to primary graft failure after HTx. We performed a retrospective review of all infants (<1 yr) who underwent Htx from three institutions. From 1999 to 2008, 92 infants (<1 yr) received Htx. Sixteen children (17%) required ECMO after Htx due to low cardiac output syndrome. Eleven (69%) infants were successfully weaned off ECMO, and 9 (56%) infants were discharged with a mean follow-up of 2.3 ± 2.5 yr. Mean duration of ECMO in survivors was 5.4 days (2-7 days) compared with eight days (2-10 days) in non-survivors (p = NS). The five-yr survival rate for all patients was 75%; however, the five-yr survival rate was 40% in the ECMO cohort vs. 80% in the non-ECMO cohort (p = 0.0001). Graft function within one month post-Htx was similar and normal between ECMO and non-ECMO groups (shortening fraction = 42 ± 3 vs. 40 ± 2, p = NS). For infants, ECMO support for primary graft failure had a lower short-term and long-term survival rate vs. non-ECMO patients. Duration of ECMO did not adversely impact graft function and is an acceptable therapy for infants after HTx for low cardiac output syndrome.

An improved in vivo method for atrioventricular node ablation via thoracotomy

The atrioventricular (AV) node is permanently damaged in approximately 3 percent of congenital heart surgery operations, requiring implantation of a permanent pacemaker. Improvements in pacemaker design and in alternative treatment modalities require an effective in vivo model of complete heart block (CHB) before testing can be performed in humans. Such a model should enable accurate, reliable, and detectable induction of the surgical pathology. Through our laboratory’s efforts in developing a tissue engineering therapy for CHB, we describe here an improved in vivo model for inducing chronic AV block. The method employs a right thoracotomy in the adult rabbit, from which the right atrial appendage may be retracted to expose an access channel for the AV node. A novel injection device was designed, which both physically restricts needle depth and provides electrical information via electrocardiogram interface. This combination of features provides real-time guidance to the researcher for confirming contact with the AV node, and documents its ablation upon formalin injection. While all animals tested could be induced to acute AV block, those with ECG guidance were more likely to maintain chronic heart block >12 h. Our model enables the researcher to reproduce both CHB and the associated peripheral fibrosis that would be present in an open congenital heart surgery, and which would inevitably impact the design and utility of a tissue engineered AV node replacement.

An improved in vivo method for atrioventricular node ablation via thoracotomy.

The atrioventricular (AV) node is permanently damaged in approximately 3% of congenital heart surgery operations, requiring implantation of a permanent pacemaker. Improvements in pacemaker design and in alternative treatment modalities require an effective in vivo model of complete heart block (CHB) before testing can be performed in humans. Such a model should enable accurate, reliable, and detectable induction of the surgical pathology. Through our laboratory's efforts in developing a tissue engineering therapy for CHB, we describe here an improved in vivo model for inducing chronic AV block. The method employs a right thoracotomy in the adult rabbit, from which the right atrial appendage may be retracted to expose an access channel for the AV node. A novel injection device was designed, which both physically restricts needle depth and provides electrical information via electrocardiogram interface. This combination of features provides real-time guidance to the researcher for confirming contact with the AV node, and documents its ablation upon formalin injection. While all animals tested could be induced to acute AV block, those with ECG guidance were more likely to maintain chronic heart block >12 h. Our model enables the researcher to reproduce both CHB and the associated peripheral fibrosis that would be present in an open congenital heart surgery, and which would inevitably impact the design and utility of a tissue engineered AV node replacement.

Arrhythmia management in the Fontan patient.

With longer duration of follow-up, as many as 50% of Fontan patients will develop atrial tachycardia, usually in association with significant hemodynamic abnormalities. Arrhythmia management in the Fontan patient is reviewed. The incidence and type of arrhythmia occurrence are examined, including macro-reentrant rhythm which involves the right atrium, reentrant rhythm localized to the pulmonary venous atrium (seen in patients with lateral tunnel procedures), and atrial fibrillation. Risk factors for development of these arrhythmias are considered, and short- and long-term therapeutic options for medical and surgical treatment are discussed. Surgical results are presented for 117 patients undergoing Fontan conversion and arrhythmia surgery (isthmus ablation (9), modified right atrial maze (38) or Cox-maze III (70)). Operative mortality is low (1/117, 0.8%). Seven late deaths occurred, and include two patients who died shortly following cardiac transplantation (2/6, 33%) after Fontan conversion and arrhythmia surgery. Overall arrhythmia recurrence is 12.8% during a mean follow-up of 56 months. Fontan conversion with arrhythmia surgery can be performed with low operative mortality, low risk of recurrent tachycardia, and marked improvement in functional status in most patients. Because the development of tachycardia is usually an electromechanical problem, attention to only the arrhythmia with medications or ablation may allow progression of hemodynamic abnormalities to either a life-threatening outcome or a point at which transplantation is the only potential option. Because cardiac transplantation in Fontan patients is associated with high early mortality, earlier consideration for surgical intervention is warranted.

Cardiac plasma cell granulomas: response to oral steroid treatment.

Plasma cell granulomas are lesions of uncertain histogenesis arising in a variety of locations, most commonly the lung. Treatment for these lesions is complete surgical excision if possible. Unresectable pulmonary lesions respond to oral corticosteroids and radiation therapy. We report the long-term outcome of two unusual pediatric cases of cardiac plasma cell granulomas originating within the right ventricle and posterior aspect of the left ventricle. The limited literature reports advocate surgical resection for this entity, with no discussion of alternative treatment strategies for unresectable lesions. We prospectively evaluated the response to postoperative oral steroid therapy, as complete surgical excision was not possible in either case. Sequential echocardiography demonstrated additional significant reduction in the size of the masses and the patients remain asymptomatic at 9 and 5.5 years follow-up, without evidence of obstruction or recurrence. Oral corticosteroids should be considered as a treatment option for any unresectable plasma cell granuloma.

Alterations in the natriuretic hormone system related to cardiopulmonary bypass in infants with congestive heart failure.

This study examined changes in the natriuretic hormone system in five infants with congestive heart failure (CHF) due to intracardiac left-to-right shunting who were exposed to cardiopulmonary bypass (CPB) during surgical repair. Plasma concentrations of three hormones [atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and dendroaspis natriuretic peptide (DNP)] and their secondary messenger, guanosine 3',5'-monophosphate (cGMP), were measured, and the biological activity of the system was quantified. At baseline, BNP and DNP concentrations were normal in our patients, a finding that is strikingly different from that of adult CHF patients, whereas ANP concentrations were elevated. Following CPB, ANP concentrations decreased (median, 175 vs 44 pg/ml; p = 0.043) and BNP concentrations increased (median, 25 vs 66 pg/ ml; p = 0.043), whereas DNP concentrations did not change. Following modified ultrafiltration, BNP concentrations increased (p = 0.043), but other natriuretic peptide concentrations did not change. The calculated biological activity of the natriuretic hormone system decreased following CPB [molar ratio, cGMP / (ANP + BNP + DNP); median, 213 vs 127; p = 0.043)]. Additional studies are needed to expand on these findings and identify patients with other types of congenital heart disease who have perioperative disturbances in the natriuretic hormone system and thus might benefit from pharmacologic intervention.

Resection of Kommerell's diverticulum and left subclavian artery transfer for recurrent symptoms after vascular ring division.

OBJECTIVES: A Kommerell's diverticulum in patients with a right aortic arch may become aneurysmal and be an independent cause of tracheoesophageal compression, even after ligation and division of a left ligamentum. We review the indications for and results of Kommerell's diverticulum resection and left subclavian artery transfer in children with a right aortic arch who previously underwent vascular ring (ligamentum) division. METHODS: From 1998 through 2001, eight children have been referred with recurrent respiratory symptoms (n=8) and/or recurrent dysphagia (n=4) after vascular ring division. Each child had a right aortic arch with a left ligamentum and had undergone division of the ligamentum elsewhere. All had a Kommerell's diverticulum that was not addressed at the initial operation. All patients had a repeat left thoracotomy with resection of the diverticulum. Five patients had division and reimplantation of the left subclavian artery into the left carotid artery to relieve the sling-like effect of the retroesophageal left subclavian artery on the right aortic arch. One other patient had primary Kommerell's diverticulum resection and transfer of the left subclavian artery to the left carotid artery. RESULTS: The mean age at the initial operation was 1.7+/-0.9 years, and the mean age at reoperation was 8.0+/-3.7 years. In all patients postoperative bronchoscopy confirmed relief of the tracheal compression. There were no complications related to the subclavian artery transfer. Two patients developed postoperative chylothorax, one requiring thoracic duct ligation. The median hospital stay was 5 days. All patients had dramatic resolution of their preoperative symptoms. CONCLUSIONS: Kommerell's diverticulum is an important anatomic structure that can cause recurrent symptoms in patients with a right aortic arch after ligamentum division. In selected patients, reoperation with resection of the Kommerell's diverticulum and transfer of a retroesophageal left subclavian artery results in relief of symptoms. This technique has become our procedure of choice as a primary operation for children with a right aortic arch and a significant Kommerell's diverticulum.

Surgical management of aortopulmonary window: a 40-year experience.

OBJECTIVES: An aortopulmonary window (APW) is a communication between the pulmonary artery (PA) and the ascending aorta in the presence of two separate semilunar valves. The purpose of this review is to describe the evolution of surgical techniques and results of surgical correction of APW at a single center over a 40-year time period. METHODS: Between 1961 and 2001, 22 patients underwent repair of APW. Age ranged from 11 days to 13 years (median 0.3 years). Associated cardiac lesions included interrupted aortic arch (IAA) (four), right PA origin from the aorta (four), ventricular septal defect (three), atrial septal defect (one), tetralogy of Fallot (one), and transposition of the great arteries (one). Mean preoperative pulmonary vascular resistance was 5.4 U/m2 (n=17). Two patients had attempted ligation without cardiopulmonary bypass (CPB), one patient had division and oversewing of the APW between clamps on CPB. Ten patients had the APW divided on CPB with primary aortic closure. Three patients had circulatory arrest for APW division, IAA repair, and anastomosis right PA to main PA. Most recently, six patients have had open transaortic patch closure (one of these had simultaneous arterial switch, one had simultaneous IAA repair). Follow-up in operative survivors ranges from 1 month to 26 years (median 8 years). RESULTS: There were five early deaths and one late death (pulmonary hypertension) in the first 16 patients where the primary strategy was APW division (37% mortality). There have been no deaths in the most recent six patients having transaortic patch closure. The patients with transaortic patch closure at a maximum of 8 years follow-up are demonstrating normal PA and aortic growth. CONCLUSIONS: Early correction of APW with a transaortic patch and repair of all other associated cardiac anomalies at the time of diagnosis is advised.

Coronary artery bypass grafting for Kawasaki disease.

Five patients with a history of Kawasaki disease underwent coronary revascularization at Children's Memorial Hospital (1988-2000). Acute disease occurred at 11 weeks to 5 years of age and revascularization procedures were performed at 8 months to 12 years (mean 6 years; interval from disease onset 5 months to 9 years). Surgical indications included abnormal stress testing with angiographic confirmation of severe coronary artery stenosis (n = 3), severe coronary artery stenosis with echocardiographic evidence of intracoronary thrombus (n = 1), and ischemic electrocardiogram changes and ventricular tachycardia during angiography (n = 1). All revascularization procedures used internal thoracic arteries including one free internal thoracic artery graft. There were no postoperative deaths (follow-up 1 month to 11 years). All patients are asymptomatic. One patient developed myocardial ischemia 4 years postoperatively with occlusion of the circumflex coronary artery (not previously grafted). This was treated successfully with percutaneous coronary angioplasty and stent placement. All grafts are patent with the exception of a single right internal thoracic artery graft which underwent involution 30 months postprocedure with concurrent recannulization of the right coronary artery. Coronary revascularization should be considered in the young patient with severe coronary abnormalities secondary to Kawasaki disease.

Total cavopulmonary conversion and maze procedure for patients with failure of the Fontan operation.

OBJECTIVES: Hemodynamic abnormalities and refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We review our experience with conversion to total cavopulmonary artery connections and arrhythmia surgery. METHODS: Between 1994 and 2001, 40 patients underwent Fontan conversion and arrhythmia surgery. Significant hemodynamic lesions such as aortic aneurysm (n = 1), atrioventricular valve insufficiency (n = 8), and pulmonary arterioplasty (n = 9) were repaired concomitantly. Thirty-four patients were in New York Heart Association class III or IV. Mean age at the original Fontan operation was 7.5 +/- 6.5 years and mean age at Fontan conversion was 18.7 +/- 9.0 years. Arrhythmia surgery has evolved from isthmus cryoablation in 10 patients to right-sided maze in 16 patients for atrial reentry tachycardia. The maze-Cox III operation was used for 14 patients with atrial fibrillation. Atrial (n = 33) and dual-chamber (n = 5) pacemakers were placed. RESULTS: There has been no early mortality. Chest tubes were removed on postoperative day 9.0 +/- 6.0. Hospital stay was 11.8 +/- 6.6 days. Three patients required cardiac transplantation at 8 days, 9 months, and 33 months postoperatively. There was 1 death 2 years postoperatively from acute myocardial infarction. For the entire series, arrhythmia recurrence is 12.5%, with only 10% of patients receiving long-term antiarrhythmic medications; these patients were among the first 8 patients in our series. Most patients are in New York Heart Association class I or II. Bruce protocol in 12 patients showed increased tolerance (P <.05). CONCLUSIONS: Fontan conversion to total cavopulmonary connection with concomitant arrhythmia surgery is excellent therapy for patients whose Fontan repair has failed. Fontan conversion is safe, improves New York Heart Association class, improves exercise tolerance, and has a low incidence of recurrent arrhythmias.

Healing of a free tracheal autograft is enhanced by topical vascular endothelial growth factor in an experimental rabbit model.

OBJECTIVE: In 1996, we introduced the free tracheal autograft technique for repair of congenital tracheal stenosis from complete tracheal rings in infants and children. Sources of possible concern with this procedure include the potential for autograft ischemia, patch dehiscence, and recurrent stenosis. Vascular endothelial growth factor is a potent angiogenic inducer (particularly in the setting of ischemia, hypoxia, or both) and is postulated to promote tissue healing. The purpose of this study was to test the hypothesis that pretreatment of tracheal autografts with topical vascular endothelial growth factor would enhance tracheal healing. METHODS: In a rabbit model of tracheal reconstruction (n = 32), an elliptically shaped portion of the anterior tracheal wall was excised. The excised portion of trachea was one third of the tracheal circumference and 2 cm in length (6 tracheal rings). This portion of trachea (the autograft) was soaked in either vascular endothelial growth factor (5 microg/mL, n = 16) or normal saline solution (n = 16) for 15 minutes before being reimplanted in the resultant tracheal opening. Animals were killed and autografts were examined at 2 weeks, 1 month, and 2 months postoperatively for gross and microscopic characteristics. RESULTS: By 2 weeks, and progressing through 1 and 2 months, autografts treated with vascular endothelial growth factor, as compared with control autografts, had reduced luminal stenosis, submucosal fibrosis, and inflammatory infiltrate (P <.05). The autografts tended to become malaligned in control animals, whereas the tracheal architecture was preserved in rabbits treated with vascular endothelial growth factor. Microvascular vessel density was significantly greater in all vascular endothelial growth factor groups (P <.05) at all time intervals. CONCLUSIONS: Topical treatment of free tracheal autografts with vascular endothelial growth factor in a rabbit tracheal reconstruction model enhanced healing, as evidenced by accelerated autograft revascularization, reduced submucosal fibrosis and inflammation, and preservation of the normal tracheal architecture. Topical vascular endothelial growth factor may improve future results of tracheal reconstruction.

Surgical management of severe truncal insufficiency: experience with truncal valve remodeling techniques.

BACKGROUND: Truncal valve insufficiency has been a significant short- and long-term risk factor for repair of truncus arteriosus. Recent reports have documented the virtues of truncal valve repair. The purpose of this report is to review our experience with truncal valve repair and illustrate our techniques. METHODS: Between 1995 and 2000, 8 patients had interventions for severe truncal valve insufficiency at primary repair (3 patients) or in conjunction with conduit replacement (5 patients). One neonate had truncal valve replacement at initial repair early in the experience. The other 7 patients had truncal valve repair, 3 by valvar suture techniques. The remaining 4 patients had leaflet excision and annular remodeling in 3 (coronary reimplantation was required in 2) and commissure resuspension in 1 patient. RESULTS: Trivial to mild truncal valve insufficiency is present in the patients who had leaflet excision and annular remodeling (n = 3) and commissure resuspension (n = 1). Of the 3 patients who had valvar suture truncal valve repair, there was one death and 2 patients required acute valve replacement. The 7 survivors are doing well 1 month to 6 years postoperatively. CONCLUSIONS: Truncal valve repair by valvar suture techniques has not been successful in our practice. Truncal valve remodeling by leaflet excision and reduction annuloplasty is an effective method for truncal valve repair. When leaflet excision of a coronary sinus of Valsalva is required, coronary artery translocation can be accomplished.

Nonadherence is associated with late rejection in pediatric heart transplant recipients.

OBJECTIVES: The objective was to study the impact of nonadherence on late rejection after pediatric heart transplantation. STUDY DESIGN: This was a retrospective cohort study of cardiac transplant recipients surviving >6 months (n = 50). Patients were stratified by episodes of late rejection. End points were defined by cyclosporin A (CSA) level, CSA level variability, and patient admission of nonadherence. RESULTS: In 15 patients there were 49 episodes of late rejection, and 37 (76%) were associated with nonadherence. Of these patients, 7 of 15 died, and 3 of 15 had transplant coronary artery disease. Risk factors for the rejection were single-parent home, non-white, older age, and higher CSA level variability. In 35 nonrejectors there were 4 deaths from sepsis, post-transplant lymphoproliferative disease, renal failure, and encephalomyelitis. CONCLUSION: Late rejection after pediatric heart transplantation is associated with nonadherence, is common during adolescence, and is associated with poor outcome.

Tracheal surgery in children: an 18-year review of four techniques.

OBJECTIVE: Review the short- and long-term outcomes of a single institution experience in infants with congenital tracheal stenosis, comparing four different operative techniques used from 1982 through 2000. METHODS: Hospital and clinic records of 50 infants and children who had surgical repair of congenital tracheal stenosis secondary to complete tracheal rings were reviewed. Age at surgery ranged from 7 days to 72 months (median, 5 months, mean 7.8+/-12 months). Techniques included pericardial patch tracheoplasty (n=28), tracheal autograft (n=12), tracheal resection (n=8), and slide tracheoplasty (n=2). All procedures were done through a median sternotomy with cardiopulmonary bypass. Seventeen patients had a pulmonary artery sling (35%), and 11 had an intracardiac anomaly (22%). RESULTS: There were three early deaths (6% early mortality), two after pericardial tracheoplasty and one after autograft. There were six late deaths (12% late mortality), five after pericardial tracheoplasty and one after slide tracheoplasty. Length of stay (median) was 60 days (pericardial tracheoplasty), 28 days (autograft), 14 days (resection), and 18 days (slide). Reoperation and/or stent placement was required in seven patients (25%) after pericardial tracheoplasty, in two patients (17%) after autograft, in no patients after resection, and in one patient (50%) after slide tracheoplasty. CONCLUSIONS: Our current procedures of choice for infants with congenital tracheal stenosis are resection with end-to-end anastomosis for short-segment stenoses (up to eight rings) and the autograft technique for long-segment stenoses. Associated pulmonary artery sling and intracardiac anomalies should be repaired simultaneously.

The left-sided aortic arch in humans, viewed as the end-result of natural selection during vertebrate evolution.

At some point during vertebrate evolution from species dwelling in water to living on land, the ancestral double or right aortic arches became single and left-sided in mammals, including humans, as the result of synchronous developments in cardiovascular and respiratory embryogenesis. Since left-sided aortic arches are unique to mammals, hemodynamics related to the placenta, specifically the requirement for a large arterial duct connecting to the descending aorta, may have led to switching from the right-sided to the left-sided arch. Additionally, development of a trilobar right lung and its bronchial tree, also unique to mammalian evolution, restricted the space above the high eparterial bronchus to a single large vessel. Consequently, mammals that mutated to the left-sided aortic arch avoided respiratory, digestive or circulatory problems that are often associated with an isolated right-sided aortic arch--something which could be considered a successful mistake. Due to natural selection, and survival of the fittest, the left-sided arch became the norm in mammals. In congenital cardiac malformations where a large arterial duct is not mandatory in fetal life, as in Fallot's tetralogy or common arterial trunk, a right-sided aortic arch continues to occur, perhaps as an atavistic reversion to the anatomy seen in ancestral vertebrates.

New directions in surgical therapy of arrhythmias.

The success of the radiofrequency catheter ablation procedure for most types of supraventricular and ventricular tachycardia, particularly in young patients, largely eliminated the role of surgical therapy of arrhythmias. However, there remains a subset of arrhythmia patients in whom the catheter approach has not been successful and types of arrhythmias with high recurrence rates following initially successful catheter ablation procedures where surgery can provide more definitive therapy. In addition, the concepts of ablation therapy can be successfully incorporated into the concomitant repair of complex congenital heart disease, resulting in single-stage therapy for structural and rhythm abnormalities. Prospectively, knowledge of the role of anatomic barriers as substrates for future reentrant arrhythmia circuits provides the opportunity to alter these circuits prophylactically at the time of initial surgical repair of congenital heart disease in an attempt to avoid the late development of tachycardia. This article describes our experience during the past decade with 71 patients undergoing arrhythmia surgery using this approach.

Successful palliation of Ebstein's malformation on the first day of life following fetal diagnosis.

Severe Ebstein's malformation has a poor prognosis when diagnosed during the neonatal period. Surgical options that have proved successful in older patients have been associated with high mortality and morbidity in neonates. We report here our success with a policy of induction at term and immediate surgical intervention when Ebstein's malformation was diagnosed prenatally.

Dexamethasone reduces the inflammatory response to cardiopulmonary bypass in children.

BACKGROUND: A randomized, prospective, double-blind study of 29 children was performed to evaluate the hypothesis that dexamethasone administration prior to cardiopulmonary bypass would decrease the inflammatory mediator release and improve the postoperative clinical course. METHODS: Fifteen children received dexamethasone (1 mg/kg intravenously) and 14 (controls) received saline solution 1 hour prior to CPB. Serial blood analyses for interleukin-6, tumor necrosis factor-alpha, complement component C3a, and absolute neutrophil count were performed. Postoperative variables evaluated included temperature, supplemental fluids, alveolar-arterial oxygen gradient, and days of mechanical ventilation. RESULTS: Dexamethasone caused an eightfold decrease in interleukin-6 levels and a greater than threefold decrease in tumor necrosis factor-alpha levels after CPB (p < 0.05). Complement component C3a and absolute neutrophil count were not affected by dexamethasone. The mean rectal temperature for the first 24 hours postoperatively was significantly lower in the group given dexamethasone than in the controls (37.2 degrees +/- 0.4 degrees C versus 37.7 degrees +/- 4 degrees C; p = 0.007). Dexamethasone-treated patients required less supplemental fluid during the first 48 hours (22 +/- 28 mL/kg versus 47 +/- 34 mL/kg; p = 0.04). Compared with controls, dexamethasone-treated children had significantly lower alveolar-arterial oxygen gradients during the first 24 hours (144 +/- 108 mm Hg versus 214 +/- 118 mm Hg; p = 0.02) and required less mechanical ventilation (median duration, 3 days versus 5 days; p = 0.02). CONCLUSIONS: Dexamethasone administration prior to CPB in children leads to a reduction in the postbypass inflammatory response as assessed by cytokine levels and clinical course.