Biomedical subjects

C L Backer

Publications and source records attributed to C L Backer.

At least 19 recordsLinked to original sources

PubMed2001

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.

Anastomosis, Surgical↗

PubMed2001

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.

Aorta↗

PubMed2001

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.

Adolescent↗

PubMed2000

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.

Anti-Inflammatory Agents↗

PubMed2000

Congenital Heart Surgery Nomenclature and Database Project: anomalies of the coronary arteries.

The extant nomenclature for coronary artery anomalies is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. The seven major categories of coronary artery anomalies are: anomalous pulmonary artery origins of the coronaries, anomalous aortic origins of the coronaries, congenital atresia of the left main coronary artery, coronary artery fistulas, coronary artery bridging, coronary aneurysms, and coronary stenosis. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail, which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented, which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Coronary Vessel Anomalies↗

PubMed2000

Congenital Heart Surgery Nomenclature and Database Project: vascular rings, tracheal stenosis, pectus excavatum.

The extant nomenclature for vascular rings, tracheal stenosis, and pectus deformities is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Vascular rings are subclassified as double aortic arch, right arch/left ligamentum, pulmonary artery sling, and innominate compression. Tracheal stenosis is subclassified as congenital complete tracheal rings (localized or long-segment) or acquired postintubation types. Pectus deformities are subclassified as pectus excavatum and carinatum (mild, moderate, severe). A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Aorta, Thoracic↗

PubMed2000

Congenital Heart Surgery Nomenclature and Database Project: patent ductus arteriosus, coarctation of the aorta, interrupted aortic arch.

The extant nomenclature for patent ductus arteriosus (PDA), coarctation of the aorta (CoAo), and interrupted aortic arch (IAA) is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. PDA is subclassified by origin, insertion, and patient weight. CoAo is subclassified into isolated CoAo, CoAo with ventricular septal defect, and CoAo with complex intracardiac anomalies. IAA is subclassified into anatomic types A, B, and C based on the location of the interruption. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Aortic Arch Syndromes↗

PubMed2000

Arterial switch after failed atrial baffle procedures for transposition of the great arteries.

BACKGROUND: Late failure of the systemic right ventricle after atrial baffle procedures in patients with transposition of the great arteries poses significant management problems. We reviewed our experience with staged conversion to arterial switch operation (ASO) in these patients. METHODS: Between 1984 and 1999, 11 patients underwent pulmonary artery band (PAB) to prepare the left ventricle for ASO conversion. One additional patient had subpulmonic stenosis and was naturally prepared. Mean age at the initial PAB was 12.2+/-7 years (range, 1.9 to 23 years). Four patients underwent reoperation to tighten the PAB before ASO. Mean interval from PAB to ASO was 1.3+/-0.9 years. RESULTS: There was no mortality from PAB. Six patients had ASO conversion and 2 died. Recent surgical modifications at the time of ASO were used to prevent neoaortic valve insufficiency and to cryoablate atrial reentry tachycardia. Four patients developed biventricular failure after PAB and had orthotopic cardiac transplantation (OCT) 14+/-10 months after PAB. The other 2 patients are still with PAB: 1 is awaiting ASO conversion and the other has insufficient left ventricular hypertrophy necessary for ASO conversion despite two preparatory PABs. CONCLUSIONS: A select group of patients with right ventricular failure after atrial baffle operations can undergo staged conversion to ASO with the opportunity for excellent long-term outcome. Surgical modifications at the time of ASO can address the problems of neoaortic insufficiency and persistent atrial arrhythmias. PAB may be a therapeutic endpoint in some patients not responding with adequate left ventricular hypertrophy. Those patients who develop biventricular failure after PAB will require cardiac transplantation.

Adolescent↗

PubMed2000

Revision of previous Fontan connections to total extracardiac cavopulmonary anastomosis: A multicenter experience.

BACKGROUND: Conversion to total extracardiac cavopulmonary anastomosis is an option for managing patients with dysfunction of a prior Fontan connection. METHODS: Thirty-one patients (19.9 +/- 8.8 years) underwent revision of a previous Fontan connection to total extracardiac cavopulmonary anastomosis at four institutions. Complications of the previous Fontan connection included atrial tachyarrhythmias (n = 20), progressive heart failure (n = 17), Fontan pathway obstruction (n = 10), effusions (n = 10), pulmonary venous obstruction by an enlarged right atrium (n = 6), protein-losing enteropathy (n = 3), right atrial thrombus (n = 2), subaortic stenosis (n = 1), atrioventricular valve regurgitation (n = 3), and Fontan baffle leak (n = 5). Conversion to an extracardiac cavopulmonary connection was performed with a nonvalved conduit from the inferior vena cava to the right pulmonary artery, with additional procedures as necessary. RESULTS: There have been 3 deaths. Two patients died in the perioperative period of heart failure and massive effusions. The third patient died suddenly 8 months after the operation. All surviving patients were in New York Heart Association class I (n = 20) or II (n = 7), except for 1 patient who underwent heart transplantation. Early postoperative arrhythmias occurred in 10 patients: 4 required pacemakers, and medical therapy was sufficient in 6. In 15 patients, pre-revision arrhythmias were improved. Effusions resolved in all but 1 of the patients in whom they were present before revision. The condition of 2 patients with protein-losing enteropathy improved within 30 days. CONCLUSIONS: Conversion of a failing Fontan connection to extracardiac cavopulmonary connection can be achieved with low morbidity and mortality. Optimally, revision should be undertaken early in symptomatic patients before irreversible ventricular failure ensues.

Adolescent↗

PubMed2000

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.

Blood Vessel Prosthesis↗

PubMed2000

Intermediate-term results of the free tracheal autograft for long segment congenital tracheal stenosis.

BACKGROUND/PURPOSE: Since 1996 a new procedure--the free tracheal autograft--has been used to repair long segment congenital tracheal stenosis (LSCTS). The purpose of this report is to examine the intermediate-term results of that technique. METHODS: Between January 1996 and July 1999, 10 infants underwent repair of LSCTS using a free tracheal autograft. Age ranged from 10 days to 23 months (mean age, 6.6 months). Six infants had a pulmonary artery (PA) sling; 5 had intracardiac anomalies. On cardiopulmonary bypass (CPB) the trachea was incised anteriorly through the area of stenosis. The midportion of the stenotic trachea was excised, and an end-to-end anastomosis was made posteriorly. The excised tracheal segment was trimmed and sutured in place anteriorly as a free autograft. In 5 patients the autograft was not long enough, and the upper portion of the tracheal opening was patched with pericardium. RESULTS: There was 1 death 26 days postoperatively in a child that had simultaneous repair of tetralogy of Fallot and required extracorporeal membrane oxygenation postoperatively for cardiac failure. The other 9 children are alive and well at 2 to 44 months postoperatively (mean follow-up, 24 months). One child had autograft dehiscence and required replacement of the autograft with an aortic homograft. Two children have tracheostomies at 6 and 36 months postoperatively. All children have had serial postoperative bronchoscopic examinations. Most recent bronchoscopies have shown widely patent tracheal lumina in all survivors. CONCLUSION: Intermediate-term follow-up of children with a free tracheal autograft continues to support our use of this technique as our procedure of choice for infants with LSCTS.

Abnormalities, Multiple↗

PubMed1999

Impact of arrhythmia circuit cryoablation during Fontan conversion for refractory atrial tachycardia.

Refractory atrial arrhythmias in late postoperative Fontan patients are usually associated with residual hemodynamic abnormalities and result in significant morbidity and mortality. Surgical revision of the Fontan anastomosis may improve hemodynamics without eliminating tachycardia. This study sought to assess the impact of surgical cryoablation of the arrhythmia circuit at the time of Fontan conversion on the clinical recurrence of tachycardia. Sixteen consecutive atriopulmonary Fontan patients with refractory atrial arrhythmias underwent surgical conversion to lateral tunnel total cavopulmonary anastomosis (15) or Fontan revision (1 patient). The initial 4 patients underwent Fontan conversions alone, without specific arrhythmia surgery. The subsequent 12 patients underwent electrophysiologically guided cryoablation of the tachycardia circuits at the time of surgical conversion. The mean age at Fontan revision was 15.6 +/- 3.8 years. Cryoablation was directed to 3 identified major tachycardia circuits: the inferomedial right atrium, the superior rim of the prior atrial septal defect patch, and along the lateral right atrial wall. Transmural antitachycardia pacemakers were implanted in 11 of the 16 patients. There was no surgical mortality in either group, and all patients improved in functional classification. All patients not undergoing cryoablation experienced recurrent symptomatic tachycardia requiring antiarrhythmic therapy (median follow-up, 54 months) versus 2 of 12 patients receiving cryoablation (median follow-up, 25 months; p <0.02). Thus, surgical cryoablation of the arrhythmia circuit at the time of Fontan conversion is highly effective in the management of refractory atrial arrhythmias, and is superior to Fontan conversion alone.

Adolescent↗

PubMed1999

The use of balloon-expandable metallic stents in the treatment of pediatric tracheomalacia and bronchomalacia.

OBJECTIVE: To evaluate the use of balloon-expandable metallic stents in the treatment of children with tracheomalacia and bronchomalacia in whom conventional therapy has failed. DESIGN: Retrospective case series. SETTING: Tertiary pediatric otolaryngology and cardiothoracic surgery referral center. PATIENTS: Six patients were identified as having undergone bronchoscopic placement of metallic balloon-expandable stents between 1994 and 1997. The age at stent placement, prior surgical interventions, and indications for and sites of stent placement were noted. Also, the complications related to stent placement and the current airway status of the patients were reviewed. INTERVENTIONS: Twelve balloon-expandable metallic angioplasty stents (Palmaz; Johnson & Johnson Interventional Systems Co, Warren, NJ) were placed bronchoscopically in 6 patients. Six stents were placed in the lower trachea, and 6 were placed in the main bronchi. The stents were balloon expanded under fluoroscopic guidance. MAIN OUTCOME MEASURE: Discontinuation of mechanical ventilation. RESULTS: The age at stent placement ranged from 1.5 to 38 months (mean age at placement, 10 months). The indications for stent placement were (1) tracheomalacia or bronchomalacia, (2) pericardial patch or slide tracheoplasty failure, and (3) bronchomalacia caused by tetralogy of Fallot and large pulmonary arteries. The primary complication of stent placement was postoperative granulation tissue formation. One patient required the removal of 2 tracheal stents because of granulation tissue formation. There were 2 deaths in the series, 1 possibly related to stent placement. Four of the 6 patients were weaned from mechanical ventilation, and 3 experienced prolonged relief of airway obstruction. CONCLUSIONS: Metallic balloon-expandable stents are effective in relieving lower tracheomalacia and bronchomalacia in select patients. Only patients in whom conventional therapy has failed should be considered for stent placement.

Airway Obstruction↗

PubMed1999

A 26-year review of pectus deformity repairs, including simultaneous intracardiac repair.

BACKGROUND: We reviewed our operative experience and long-term results with repair of pectus excavatum and carinatum deformities through a vertical midline approach, including those cases with simultaneous intracardiac repair. METHODS: From 1972 through 1998, 120 children underwent pectus deformity repair. Operative technique used a vertical midline incision with subperichondrial resection of deformed cartilages and an anterior sternal osteotomy. Thirty-five patients had a temporary metal bar for retrosternal support for 6 months; 85 underwent repair without a bar. Patients and parents were asked to assess the outcome after pectus repair as poor, fair, good, or excellent. RESULTS: There were 94 male and 26 female patients (mean age, 8.4 years; range, 3 to 21 years). There were 111 cases of pectus excavatum and 9 of pectus carinatum. Fourteen children (11.5%) had an associated congenital heart defect; 9 patients had simultaneous pectus and intracardiac repair. One patient was referred for emergent open heart repair and pectus repair after attempted "Nuss" repair resulted in a perforated right atrium, perforated right ventricle, and partially disrupted tricuspid valve apparatus. There were no deaths and only one significant complication, which required a return to the operating room for bleeding. Morbidity was not higher in patients with simultaneous intracardiac repair. Long-term follow-up was established in 83% of patients. Results were classified as excellent in 64 patients (64%), good in 25 (25%), fair in 8 (8%), and poor in 3 (3%). Thirty (86%) of 35 patients with a sternal bar had excellent results versus 34 (52%) of 65 without a bar (p = 0.004); 97% of patients who underwent repair with a sternal bar classified the result as excellent or good. CONCLUSIONS: Long-term results of pectus excavatum and carinatum repair through a vertical midline approach are excellent. Outcome with a temporary sternal bar is superior to outcome without a bar. Concomitant repair of congenital heart defects and pectus deformity may be performed successfully without additional morbidity.

Adolescent↗

PubMed1999

Right aortic arch, right ligamentum, absent left pulmonary artery: a rare vascular ring.

A 5-month-old infant presented with respiratory failure secondary to severe right bronchial compression. Diagnostic imaging revealed a right aortic arch and absent left pulmonary artery. Surgical relief was obtained via median sternotomy by dividing a right ligamentum and pexing the enlarged right pulmonary artery to the ascending aorta.

Aorta, Thoracic↗

PubMed1999

Pulmonary artery sling: results with median sternotomy, cardiopulmonary bypass, and reimplantation.

BACKGROUND: The classic surgical approach to pulmonary artery (PA) sling has been through a left thoracotomy with division of the left PA and reimplantation into the main PA anterior to the trachea. Another approach is anterior left PA translocation with distal tracheal resection. Since 1985, we have repaired PA sling with a median sternotomy approach, cardiopulmonary bypass, and division and reimplantation of the left PA into the main PA with simultaneous repair of associated tracheal stenosis. The purpose of this review is to determine the outcome of that strategy. METHODS: From 1985 to 1998, 16 infants had surgical treatment of PA sling, 14 had left PA division and reimplantation into the MPA, 2 patients had repair using the translocation technique. Mean age at repair was 6.9 months, median age was 4 months. All infants, except 1 with an absent right lung, were operated on at the time of diagnosis. All had rigid bronchoscopy, which revealed associated complete tracheal rings in 12 patients. Seven patients had tracheal repair with pericardial tracheoplasty, 4 had repair using a tracheal autograft technique, and 2 had a distal tracheal resection (one for tracheomalacia). Of the 2 patients having the translocation technique, 1 had a severely hypoplastic right lung and the other had complete absence of the right lung. RESULTS: There has been no operative mortality. Hospital stay ranged from 5 to 188 days (mean 36 +/- 42 days). There was 1 late death 7 months postoperatively from respiratory complications of pericardial tracheoplasty. All left pulmonary arteries are patent and blood flow to the left lung by nuclear scan (n = 10) ranges from 24% to 46% (mean 35% +/- 9%). CONCLUSION: The strategy of median sternotomy, cardiopulmonary bypass, and left PA division and reimplantation into the main PA with simultaneous tracheal repair has resulted in a low operative mortality and excellent patency of the left pulmonary artery. Results with repair of the commonly associated complete tracheal rings has recently improved with the use of the free tracheal autograft technique.

Anastomosis, Surgical↗

PubMed1999

Supraarterial decompression myotomy for myocardial bridging in a child.

A 10-year-old boy presented with a history of exertional chest pain. An electrocardiogram demonstrated an inferior apical myocardial infarction. Cardiac catheterization revealed myocardial bridging of the left anterior descending coronary artery with evidence of intramyocardial obstruction during systole. The patient underwent successful treatment with supraarterial decompression myotomy and remains symptom free at 1 year.

Angina Pectoris↗

PubMed1999

Bidirectional Glenn shunt in association with congenital heart repairs: the 1(1/2) ventricular repair.

BACKGROUND: The bidirectional Glenn shunt has been used to incorporate a smaller tripartite ventricle into the circulation and create pulsatile pulmonary artery flow. We reviewed our operative experience and assessed hemodynamics of the bidirectional Glenn shunt in 1(1/2) ventricular repair or in conjunction with other repairs of congenital heart defects. METHODS: Between 1992 and 1998, 15 patients (mean age, 8.1+/-7.9 years) had bidirectional Glenn shunt in association with repair of congenital heart defects. Eighty-seven percent had at least one previous operation. All patients had simultaneous or previous intracardiac repair and had bidirectional Glenn shunt to volume unload the small right ventricle (group A, n = 7), to unload the poorly functioning right ventricle (group B, n = 2), to redirect superior vena cava-pulmonary venous atrial connection to treat cyanosis (group C, n = 2), or to unload the pulmonary left ventricle for residual intracavitary hypertension in patients with L-transposition of the great arteries, ventricular septal defect, and pulmonary stenosis (group D, n = 4). Intraoperative hemodynamic assessment was done in 2 patients in group A by selective use of inflow occlusion and flow probes. RESULTS: All patients survived. Four patients had successful, concurrent arrhythmia circuit cryoablation for Wolf-Parkinson-White syndrome (n = 1) or atrial reentry tachycardia (n = 3). Superior and inferior vena caval flow averaged 36% and 64% of cardiac output, respectively. Postoperative superior vena caval pressure (n = 13) was 13.7+/-4.0 mm Hg with pulmonary arterial flow pattern contributed by the ventricle in systole (pulsatile) and the superior vena cava in diastole (laminar). CONCLUSIONS: The bidirectional Glenn shunt is an effective adjunct to congenital heart repair to treat pulmonary ventricular pressure-volume problems and anomalous superior vena caval to left atrial connections.

Adolescent↗