Standardized delivery room management for neonates with a prenatal diagnosis of congenital heart disease: A model for improving interdisciplinary delivery room care.

Precise characterization of cardiac anatomy and physiology through fetal echocardiography can predict early postnatal clinical course. Some neonates with prenatally defined critical congenital heart disease have anticipated precipitous compromise during perinatal transition for which specialized, diagnosis-specific delivery room care can be arranged to expeditiously stabilize cardiopulmonary hemodynamics. In this article, we describe our institutional approach to the delivery room care of neonates with prenatally diagnosed congenital heart disease, emphasizing our diagnosis-specific care pathways for newborns with critical disease.

Survival after reconstructive surgery for hypoplastic left heart syndrome: A 15-year experience from a single institution.

BACKGROUND: There are limited data regarding the long-term survival of patients who have undergone reconstructive surgery for hypoplastic left heart syndrome (HLHS). We reviewed the 15-year experience at our institution to examine survival in the context of continued improvements in early operative results. METHODS AND RESULTS: Between 1984 and 1999, 840 patients underwent stage I surgery for HLHS. From review of medical records and direct patient contact, survival status was determined. The 1-, 2-, 5-, 10-, and 15-year survival for the entire cohort was 51%, 43%, 40%, 39%, and 39%, respectively. Late death occurred in 14 of the 291 patients discharged to home after the Fontan procedure, although only 1 patient has died beyond 5 years of age. Heart transplantation after stage I reconstruction was performed in 5 patients. Later era of stage I surgery was associated with significantly improved survival (P:<0.001). Three-year survival for patients undergoing stage I reconstruction from 1995 to 1998 was 66% versus 28% for those patients undergoing surgery from 1984 to 1988. Age >14 days at stage I and weight <2.5 kg at stage I were also associated with higher mortality (P:=0.004 and P:=0.01, respectively). Other variables, including anatomic subtype, heterotaxia, and age at subsequent staging procedures, were not associated with survival. CONCLUSIONS: Over the 15-year course of this study, early- and intermediate-term survival for patients with HLHS undergoing staged palliation increased significantly. Late death and the need for cardiac transplantation were uncommon.

Developmental and neurological status of children at 4 years of age after heart surgery with hypothermic circulatory arrest or low-flow cardiopulmonary bypass.

BACKGROUND: It is not known whether developmental and neurological outcomes in the preschool period differ depending on whether the predominant vital organ support strategy used in infant heart surgery was total circulatory arrest (CA) or low-flow cardiopulmonary bypass. METHODS AND RESULTS: Infants with D-transposition of the great arteries who underwent an arterial-switch operation were randomly assigned to a support method consisting predominantly of CA or low-flow cardiopulmonary bypass. Developmental and neurological status were evaluated blindly at 4 years of age in 158 of 163 eligible children (97%). Neither IQ scores nor overall neurological status were significantly associated with either treatment group or duration of CA. The CA group scored lower on tests of motor function (gross motor, P=0.01; fine motor, P=0.03) and had more severe speech abnormalities (oromotor apraxia, P=0.007). Seizures in the perioperative period, detected either clinically or by continuous electroencephalographic monitoring, were associated with lower mean IQ scores (12.6 and 7.7 points, respectively) and increased risk of neurological abnormalities (odds ratios, 8.4 and 5.6, respectively). The performance of the full cohort was below expectations in several domains, including IQ, expressive language, visual-motor integration, motor function, and oromotor control. CONCLUSIONS: Use of CA to support vital organs during open heart surgery in infancy is associated, at the age of 4 years, with worse motor coordination and planning but not with lower IQ or with worse overall neurological status.

Impact of inspired gas mixtures on preoperative infants with hypoplastic left heart syndrome during controlled ventilation.

BACKGROUND: Management strategies for preoperative infants with hypoplastic left heart syndrome (HLHS) include increased inspired nitrogen (hypoxia) and increased inspired carbon dioxide (hypercarbia). There are no studies directly comparing these 2 therapies in humans. This study compares the impact of hypoxia versus hypercarbia on oxygen delivery, under conditions of fixed minute ventilation. METHODS AND RESULTS: Ten anesthetized and paralyzed preoperative infants with HLHS were evaluated in a prospective, randomized, crossover trial comparing hypoxia (17% FIO(2)) with hypercarbia (2.7% FICO(2)). Each patient was treated in a random order (10 minutes per condition) with a recovery period (15 to 20 minutes) in room air. Arterial (SaO(2)) and superior vena caval (SvO(2)) co-oximetry and cerebral oxygen saturation (ScO(2)) measurements were made at the end of each condition and recovery period. ScO(2) was measured by near infrared spectroscopy. Hypoxia significantly decreased both SaO(2) (-5.2+/-1.1%, P=0.0014) and SvO(2) (-5.6+/-1.7%, P=0.009) compared with baseline, but arteriovenous oxygen saturation (AVO(2)) difference (SaO(2)-SvO(2)) and ScO(2) remained unchanged. Hypercarbia decreased SaO(2) (-2.6+/-0.6%, P=0.002) compared with baseline but increased both ScO(2) (9.6+/-1.8%, P=0.0001) and SvO(2) (6+/-2.2%, P=0.022) and narrowed the AVO(2) difference (-8.5+/-2.3%, P=0.005). Both hypoxia and hypercarbia decreased the balance between pulmonary and systemic blood flow (Qp:Qs) compared with baseline. CONCLUSIONS: In preoperative infants with HLHS, under conditions of anesthesia and paralysis, although Qp:Qs falls in both conditions, oxygen delivery is unchanged during hypoxia and increased during hypercarbia. These data cannot differentiate cerebral from systemic oxygen delivery.

Cognitive development after the Fontan operation.

BACKGROUND: Patients with a single ventricle have multiple risk factors for central nervous system injury, both before and after the Fontan procedure. METHODS AND RESULTS: A geographically selected cohort was invited to undergo standardized testing, including age-appropriate measures of intelligence quotient (IQ) and achievement tests. Historical information was obtained by chart review and patient questionnaires. Of the 222 eligible patients, 133 (59.9%) participated. Median age at testing was 11.1 years (range, 3. 7 to 41.0 years), 6.0 years (range, 1.6 to 19.6 years) after surgery. Mean full-scale IQ was 95.7+/-17.4 (P<0.006 versus normal); 10 patients (7.8%) had full-scale IQ scores <70 (P=0.001). After adjustment for socioeconomic status, lower IQ was associated with the use of circulatory arrest before the Fontan operation (P=0.002), the anatomic diagnoses of hypoplastic left heart syndrome (P<0.001) and "other complex" (P=0.05), and prior placement of a pulmonary artery band (P=0.04). Mean composite achievement score was 91.6+/-15. 4 (P<0.001 versus normal); 14 patients (10.8%) scored <70 (P<0.001). After adjustment for socioeconomic status, independent risk factors for low achievement scores included the diagnoses of hypoplastic left heart syndrome (P=0.004) and "other complex" (P=0.003) or prior use of circulatory arrest (P=0.03), as well as a reoperation with cardiopulmonary bypass within 30 days of the Fontan (P=0.01). CONCLUSIONS: Most individual patients palliated with the Fontan procedure in the 1970s and 1980s have cognitive outcome and academic function within the normal range, but the performance of the cohort is lower than that of the general population.

Video-assisted thoracoscopic vascular ring division in infants and children.

OBJECTIVES: This study evaluated our early experience with video-assisted thoracoscopic vascular ring division and compared this approach with division by means of a conventional open thoracotomy. BACKGROUND: Video-assisted thoracoscopic techniques reduce surgical trauma and have been applied to several adult thoracic procedures; however, pediatric applications have been limited. We developed instruments and techniques for video-assisted thoracoscopic vascular ring division in the pediatric population. METHODS: We compared patient characteristics, operative results and postoperative hospital courses of all patients undergoing vascular ring division by a video-assisted approach with a historical control group of all patients undergoing division by an open thoracotomy between January 1991 and December 1992. RESULTS: Eight patients (median age 5 months, range 40 days to 5.5 years; median weight 6.2 kg, range 1.8 to 17.1) underwent video-assisted thoracoscopic vascular ring division. Four had a double aortic arch with an atretic left arch and a left ligamentum, and four had a right aortic arch with aberrant left subclavian artery and a left ligamentum. All eight had successful ring division with symptomatic relief and no mortality. A limited thoracotomy was performed in three patients to divide patent vascular structures, and the hospital period was prolonged in one because of chylothorax. These eight patients were compared with a historical cohort of eight pediatric patients having vascular ring division performed by a conventional thoracotomy. The two groups did not differ in age, weight, intensive care unit or postoperative hospital stay, duration of intubation or thoracostomy tube or hospital charges. Total operating room time was longer for the group undergoing video-assisted operation. CONCLUSIONS: Early results for video-assisted thoracoscopic vascular ring division are comparable to those of the conventional surgical approach. With further refinement in technique and instrumentation, video-assisted surgical intervention may become a viable alternative to open thoracotomy for management of the symptomatic vascular ring.

Enlarged bronchial arteries after early repair of transposition of the great arteries.

OBJECTIVES: This study was undertaken to define the incidence of enlarged bronchial arteries after early surgical repair of transposition of the great arteries by the arterial switch operation, and to report the results of catheter-directed therapy in five patients. BACKGROUND: Pathologic and angiographic studies have demonstrated enlarged bronchial arteries in patients with transposition of the great arteries. METHODS: A subjective 4-point scale was used to grade postoperative angiograms performed in 119 patients at our institution between January 1983 and December 1991. Grades 0 and 1 were designated if there was no opacification of the pulmonary arteries or veins, whereas grades 2 and 3 were assigned if there was such opacification. The median age at repair was 8 days (range 1 day to 13 months) and the median age at catheterization was 11.2 months (range 3.6 to 58.5). An intact ventricular septum was present in 84 (71%) of 119 patients. RESULTS: Significantly increased bronchial flow (grade 2 or 3) was present in 55 (46%) of 119 patients. Age at repair, age at catheterization and interval between repair and catheterization were not associated with significantly increased bronchial flow; however, an intact ventricular septum was weakly associated with increased flow (p = 0.04). Coil embolization was performed in five patients with complete occlusion of the vessels and no significant complications. CONCLUSIONS: Abnormally enlarged bronchial arteries are frequently identified at postoperative catheterization despite early repair and may explain continuous murmurs or persistent cardiomegaly in patients with otherwise normal noninvasive findings. When clinically indicated, catheter-directed therapy can be performed with good results.

Impact of early ventricular unloading on exercise performance in preadolescents with single ventricle Fontan physiology.

OBJECTIVES: We sought to determine if early ventricular volume unloading improves aerobic capacity in patients with single ventricle Fontan physiology. BACKGROUND: Surgical strategies for patients with single ventricle include intermediate staging or early Fontan completion to reduce the adverse affects of prolonged ventricular volume load. The impact of this strategy on exercise performance has not been evaluated. METHODS: Retrospectively, we reviewed the exercise stress test results of all preadolescents with single ventricle Fontan physiology. "Volume unloading" was considered to have occurred at the time of bidirectional cavopulmonary anastomosis or at the time of Fontan surgery in those patients who did not undergo intermediate staging. Potential predictors of aerobic capacity were analyzed using multivariate regression. RESULTS: The patients (n = 46) achieved a mean percentage predicted of maximal oxygen consumption (VO2max) of 76.1% +/- 21.1%. The mean age at the time of volume unloading was 2.7 +/- 2.4 years, and the mean age at testing was 8.7 +/- 2 years. Intermediate staging was performed in 16 of 46 patients (35%). In multivariate analysis, younger age at volume unloading was associated with increased aerobic capacity (p = 0.003). Other variables were not predictive. The subgroup of patients who underwent volume unloading before two years of age achieved a mean percentage predicted VO2max of 88.6% +/- 24.1%. CONCLUSIONS: Preadolescents with single ventricle who undergo volume unloading surgery at an early age demonstrate superior aerobic capacity compared with those whose surgery is delayed until a later age.

Coronary echocardiography in 406 patients with d-loop transposition of the great arteries.

OBJECTIVES: The reliability of two-dimensional echocardiography for determining the proximal coronary artery anatomy in d-loop transposition of the great arteries was investigated in 406 infants who underwent surgical repair at one institution. BACKGROUND: The origin and proximal course of the main coronary arteries can affect the surgical results of the arterial switch operation. Preoperative determination of the coronary artery anatomy appears to be advantageous for the surgeon. METHODS: All infants with d-loop transposition who underwent a two-dimensional echocardiogram and primary surgical repair at our institution between 1987 and 1992 were identified, and the echocardiographic, operative and, when available, autopsy reports were reviewed for coronary artery anatomy, presence of a ventricular septal defect and the spatial relation between the arterial roots. The two-dimensional echocardiographic findings were compared with surgical or autopsy findings. The relation between proximal coronary artery anatomy and 1) a ventricular septal defect, and 2) the spatial orientation of the arterial roots was investigated. Twenty-seven infants diagnosed with an intramural coronary artery were not included because they are the subjects of another report. RESULTS: Excluding intramural coronary artery patterns, 10 different types of coronary artery anatomy were seen in these 406 patients. The coronary arteries were imaged adequately in 387 (95%) of the 406 patients. The coronary artery anatomy was determined correctly by two-dimensional echocardiography in 369 (95.4%) of the 387 patients, with 18 errors in diagnosis. During the most recent 2.5 years, 193 (98.5%) of 196 patients were diagnosed correctly, with three diagnostic errors. Patients with a ventricular septal defect or side-by-side great arteries are more likely to have an unusual coronary pattern. CONCLUSIONS: Echocardiography appears to be highly reliable for determining proximal coronary artery anatomy in d-loop transposition of the great arteries. An unusual coronary artery pattern is more likely in patients with side-by-side great arteries or posterior aorta or a ventricular septal defect, or both.

Results of the arterial switch operation in patients with transposition of the great arteries and abnormalities of the mitral valve or left ventricular outflow tract.

Between January 1983 and October 1989, 290 patients underwent an arterial switch operation for transposition of the great arteries; 30 (10.3%) of the patients had abnormalities of the left ventricular outflow tract or mitral valve, or both. These abnormalities included isolated pulmonary valve stenosis (n = 9), septal (dynamic) subpulmonary stenosis (n = 5), anatomic (fixed) subpulmonary stenosis (n = 7), abnormal mitral chordae attachments (n = 2) or a combination of abnormalities (n = 7). There were two early deaths, one of which was due to previously unrecognized mitral stenosis and a subpulmonary (neo-aortic) membrane and one late death due to presumed coronary obstruction. Of the nine patients with pulmonary valve abnormalities due to either a bicommissural (n = 5) or a thickened tricommissural (n = 4) valve, only one underwent valvotomy. Peak systolic ejection gradients in these nine patients measured preoperatively ranged from 0 to 50 mm Hg. At follow-up study 5 to 30 months postoperatively, the neo-aortic valve gradient was less than or equal to 15 mm Hg in all patients; three patients had mild neo-aortic regurgitation. Preoperative gradients may overestimate the degree of obstruction because of the increased pulmonary blood flow present in transposition. No patient with "dynamic" subpulmonary obstruction before the arterial switch operation had a surgical procedure performed on the left ventricular outflow tract; none had evidence of subaortic obstruction after the arterial switch.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial perfusion, function and exercise tolerance after the arterial switch operation.

OBJECTIVES: This study was conducted to determine the prevalence of myocardial perfusion abnormalities at rest and exercise and to assess exercise capacity in children after the arterial switch operation. BACKGROUND: There have been sporadic reports of myocardial ischemia or sudden death in children after the arterial switch operation for transposition of the great arteries, possibly related to inadequate coronary perfusion due to kinking or stenosis of the translocated coronary arteries. METHODS: Myocardial perfusion at rest and peak exercise was assessed using the scintigraphic agent technetium-99m methoxyisobutyl isonitrile (sestamibi). Exercise capacity was determined with a modified Bruce protocol. Ambulatory electrocardiographic (ECG) Holter monitoring was performed. Ventricular function, contractility and wall motion were assessed echocardiographically. RESULTS: Twenty-three children (aged 4.2 to 7.9 years) underwent evaluation. Abnormalities were found on the rest perfusion scans in 22 children (95.6%). The left ventricular myocardium was divided into 13 segments for analysis. Of 299 rest segments, 225 (75.3%) were normal, 11 (3.7%) showed mild defects, 45 (15%) moderate defects and 18 (6%) severe defects at rest. At peak exercise, 237 segments (79.3%) were normal, 24 (8%) showed mild defects, 33 (11%) moderate defects and 5 (1.7%) severe defects. Compared with rest studies, myocardial perfusion grade at exercise was unchanged in 246 segments (82.3%), improved in 42 (14%) and worsened in 11 (3.7%). All patients had normal exercise tolerance without symptoms or ischemic ECG changes. No ventricular tachycardia was seen on Holter monitoring. All patients had a shortening fraction > or = 27%. Left ventricular contractility was normal in 12 children in whom it was assessed. Regional wall motion was normal in 17 children with adequate echocardiographic images for this analysis. CONCLUSIONS: Myocardial perfusion scan abnormalities assessed by technetium-99m sestamibi are common after an arterial switch operation. These abnormalities are of uncertain clinical significance and generally lessen with exercise. The normal exercise tolerance without symptoms or ECG changes suggests that myocardial perfusion is adequate during the physiologic stress of exercise in children up to 8 years after an arterial switch operation.

What factors are important to parents making decisions about neonatal research?

BACKGROUND: Although parents of neonates with congenital heart disease are often asked permission for their neonates to participate in research studies, little is known about the factors parents consider when making these decisions. OBJECTIVE: To determine the reasons for parents' decisions about participation in research studies. METHODS: Qualitative analysis of the unsolicited comments of 34 parents regarding reasons for agreeing or declining to participate in research studies. Parents' comments were offered spontaneously during interviews about clinical care decisions for neonates with congenital heart disease. RESULTS: Parents cited five types of reason for or against permitting their newborn to participate in research studies: societal benefit (n = 18), individual benefit for their infant (n = 16), risk of study participation (n = 10), perception that participation posed no harm (n = 9), and anti-experimentation views (n = 4). CONCLUSION: Addressing parental decision making in the light of these reasons could enhance the parental permission process for parents of critically ill neonates.

Cognitive development of children following early repair of transposition of the great arteries using deep hypothermic circulatory arrest.

Twenty-eight children who underwent corrective cardiac surgery in early infancy had developmental evaluations to explore whether cardiopulmonary bypass perfusion variables are associated with later cognitive function. All had transposition of the great arteries repaired by the arterial switch operation using deep hypothermic circulatory arrest. The mean duration of deep hypothermic circulatory arrest was 64 +/- 10 minutes (mean +/- SD). Median age at repair was 4 days (range 1 to 125 days). Tests of development were administered at age 7 to 53 months: Bayley Scales for children younger than 30 months of age (n = 18) and McCarthy Scales for older children (n = 10). Overall cognitive development score was 101.2 +/- 11.1. Duration of deep hypothermic circulatory arrest was not associated with performance. However, for core cooling periods of less than 20 minutes' duration, shorter cooling periods were associated with lower scores (r = .85, n = 11, P less than .001). These data suggest that patients undergoing relatively long periods of deep hypothermic circulatory arrest may require some minimum time of cardiopulmonary bypass cooling to avoid central nervous system injury.

Comparison of technetium-99m MIBI and thallium-201 chloride myocardial scintigraphy in infants.

Myocardial perfusion scintigraphy was performed with both 201Tl and a new six coordinate monocationic isonitrile complex of 99mTc, [99mTc]2-methoxyisobutylisonitrile (MIBI), on 11 infants who had undergone the arterial switch procedure for transposition of the great arteries. Unlike 201Tl which can show rapid and variable rates of washout from myocardium, 73% of the initial first-pass activity of the isonitrile complex in the myocardium remains 1 hr after intravenous administration. The images obtained with [99mTc]MIBI required a shorter recording time, entailed less radiation exposure to the patient, and were qualitatively at least as good as those obtained with 201Tl. No infant had perfusion abnormalities. The potential applications of the isonitrile complexes for myocardial perfusion scintigraphy in children are discussed.

Coronary artery abnormalities detected at cardiac catheterization following the arterial switch operation for transposition of the great arteries.

Because the arterial switch operation has become the routine surgical approach for transposition of the great arteries, there is increasing awareness of adverse sequelae in some survivors. For the arterial switch to be considered the procedure of choice for transposition of the great arteries, long-term patency and normal function of the translocated coronary arteries must be achieved. We reviewed the cineangiograms and hemodynamic data in 366 patients who underwent postoperative catheterization after arterial switch operation. Of these, 13 patients (3%) had previously unsuspected coronary abnormalities diagnosed angiographically. No patient had noninvasive evidence of resting systolic dysfunction. Findings included left main coronary artery stenosis (n = 3) or occlusion (n = 2), anterior descending coronary artery stenosis (n = 1) or occlusion (n = 2), right coronary artery stenosis (n = 1) or occlusion (n = 1), and small coronary artery fistulas (n = 3). One patient died suddenly 3.3 years after surgery, 1 patient is lost to follow-up, and the remaining 10 patients are alive and asymptomatic up to 11 years after surgery.

Long-term outcome in patients with pacemakers following the Fontan operation.

Patients with pacemakers after Fontan surgery compared favorably with nonpaced patients with respect to survival. In patients with atrioventricular block, dual chamber pacing was superior to VVI pacing.

Status of the left ventricle after arterial switch operation for transposition of the great arteries. Hemodynamic and echocardiographic evaluation.

BACKGROUND: The potential for improved preservation of systemic ventricular function represents an important reason for the increasing popularity of the arterial switch operation. In support of this expectation, prior studies in patients early after arterial switch operation have found normal ventricular contractility and function. This study was conducted to extend those observations to up to 10 years of follow-up and to directly examine the effects of a coexisting ventricular septal defect or short-term preparatory banding of the pulmonary artery before the arterial switch operation. METHODS: Patients operated on from 1983 through 1991 were included. Echocardiographic and catheterization data were collected as part of a prospective evaluation of outcome in all patients who undergo the arterial switch operation at Boston Children's Hospital, with inclusion of data from the most recent catheterization only. Echocardiograms performed at least 6 months after the operation were included, with assessment of both the most recent status as well as serial trends. Whenever possible, echocardiographic evaluation included data necessary to perform analysis of ventricular mechanics including indices of afterload, preload, and contractility. Comparison was made to normal values and between subgroups defined on the basis of an arterial switch operation with or without ventricular septal defect and those who had a rapid two-stage arterial switch operation. RESULTS: Invasive measures of left and right ventricular filling pressures, cardiac index, and pulmonary vascular resistance did not differ among the three groups. Overall, echocardiographic left ventricular end-diastolic dimension, wall thickness, mass, afterload (end-systolic wall stress), function (fractional shortening and rate-corrected velocity of fiber shortening), contractility (stress-velocity and stress-shortening relations), and preload were normal, and none of these variables was different between the groups with and without a ventricular septal defect. Serial evaluation indicated a slight but significant trend toward ventricular dilatation, perhaps related to a relatively high incidence of at least mild aortic regurgitation (30%). In contrast, in the rapid two-stage group the echocardiographic indices of left ventricular function (fractional shortening and velocity of fiber shortening) and contractility (stress-velocity and stress-shortening relations) were found to be mildly but significantly reduced compared with normal subjects and with the other arterial switch operation groups. Over the duration of follow-up encompassed by this study, no tendency toward progressive depression of function was seen. CONCLUSIONS: As the length of observation after the arterial switch operation continues to increase, left ventricular size, mass, functional status, and contractility continues to be normal, with no evidence of time-related deterioration of function. As previously reported, the rapid two-stage arterial switch operation does represent a higher risk for mild impairment of myocardial mechanics.

Assessment of pulmonary/systemic blood flow ratio after first-stage palliation for hypoplastic left heart syndrome: development of a new index with the use of doppler echocardiography.

OBJECTIVE: Circulatory maldistribution is believed to be a major cause of early death after first-stage palliation for hypoplastic left heart syndrome. Flow reversal in the reconstructed aorta may reflect the pulmonary/systemic blood flow ratio. The purpose of our study was to investigate the utility of arterial PO (2), arterial oxygen saturation, and a newly developed Doppler-derived flow index in predicting the pulmonary/systemic flow ratio after first-stage palliation for hypoplastic left heart syndrome. METHODS: Twenty-four infants who underwent first-stage palliation for hypoplastic left heart syndrome or a variant were studied. Superior vena cava blood samples were drawn to estimate the mixed venous saturation and permit calculation of the pulmonary/systemic blood flow ratio. Fifty-four samples were evaluated within the first 24 hours after surgery. Simultaneous blood draw and Doppler echocardiography were performed with interrogation in the distal aspect of the arch reconstruction. The ratio of the Doppler velocity-time integral of retrograde flow to the velocity-time integral of forward flow was calculated and compared with the pulmonary/systemic blood flow ratio RESULTS: The median mixed venous saturation for the 54 samples was low (38.5%; range, 18%-64%). The median calculated pulmonary/systemic blood flow ratio was 1.4:1 (range, 0.3:1 to 4. 2:1). Pulse pressure, mixed venous saturation, and arterial PO (2) were not statistically significant predictors of the measured pulmonary/systemic blood flow ratio. Although both aortic oxygen saturation (R (2) = 0.84, P <.01) and Doppler flow reversal ratio (R (2) = 0.94, P <.001) were significantly associated with the measured pulmonary/systemic blood flow ratio, the model coefficient of determination was greatest for Doppler flow reversal ratio. CONCLUSION: Measures of arterial oxygen saturation and arterial PO (2) may be misleading in assessing the circulatory status of infants after first-stage palliation for hypoplastic left heart syndrome. Doppler echocardiography, through use of the Doppler flow reversal ratio, provides a more useful measure of pulmonary/systemic blood flow ratio. Low mixed venous saturation after surgery may be due to factors other than pulmonary overcirculation, such as ventricular dysfunction and low cardiac output.

Video-assisted thoracoscopic surgery for congenital heart disease.

Video-assisted endoscopic techniques have reduced operative trauma in adult thoracic and general surgery, but applications in children with congenital heart disease have been limited. We report the development of video-assisted thoracic surgery procedures for neonates and infants with cardiovascular disease. Endoscopic instruments and techniques for pediatric cardiovascular procedures were designed and tested in the animal laboratory. Forty-eight operations were subsequently performed in 46 pediatric patients ranging in age from 2 hours to 14 years (median 9 months), weighing from 575 grams to 54 kg (median 8.5 kg). Clinical applications included seven different surgical procedures: patent ductus arteriosus interruption in infants (n = 26) and premature neonates (n = 5), vascular ring division (n = 8), pericardial drainage and resection (n = 3), arterial and venous collateral interruption (n = 2), thoracic duct ligation (n = 2), epicardial pacemaker lead insertion (n = 1), and diagnostic thoracoscopy (n = 1). There was no operative mortality. Technical success, defined as a video-assisted procedure completed without incising chest wall muscle or spreading the ribs, was achieved in 39 of 48 procedures (82%), with thoracotomy required to complete nine procedures. Most patients (22/25, 88%) undergoing elective ductus ligation were extubated in the operating room and discharged from the hospital within 48 hours of the operation. Eight of the last 10 patients having ductus ligation were discharged on the first postoperative day. Residual ductal flow was assessed by (1) transesophageal echocardiography in the operating room (incidence: 0/25, 0%, 70% CL 0% to 7.3%); (2) discharge auscultation (incidence: 1/30, 3%, 70% CL 0.5% to 10.8%); and (3) follow-up Doppler echocardiography (incidence: 3/25, 12%, 70% CL 5.4% to 22.6%). Video-assisted thoracoscopic techniques can be safely applied to pediatric patients with patent ductus arteriosus and vascular rings and may become an effective addition to the staged management of more complex forms of congenital heart disease.

Staged operation to Fontan increases the incidence of sinoatrial node dysfunction.

Morbidity and mortality of total cavopulmonary connection (modified Fontan procedure) may be decreased in many patients with single ventricle in whom the risk of surgery is high by performing the operations in a staged fashion. Each operative intervention, however, exposes the sinoatrial node region to risk of injury, and a multistaged approach may increase the risk of altered sinoatrial node function in these patients. The purpose of this study was to compare the prevalence of perioperative arrhythmias in patients undergoing either a primary or staged approach to the Fontan operation. Records were retrospectively reviewed for all patients having a Fontan procedure between January 1988 and December 1992. Of 324 patients undergoing a Fontan operation, 227 had a Fontan operation without a prior cavopulmonary shunt (group 1) and 97 had a cavopulmonary shunt before a Fontan operation (group 2). Arrhythmias were classified as altered sinoatrial node function, supraventricular tachycardia, or atrioventricular block. The prevalence of both transient (resolving before hospital discharge) and fixed (persisting until hospital discharge) altered sinoatrial node function was similar for the two groups after cavopulmonary shunt or primary Fontan despite a heterogeneous patient population (group 1: 10.6%/4.4%; group 2: 10.3%/3.1%; p=0.28). Conversion from cavopulmonary shunt to Fontan in group 2 resulted in a higher prevalence of altered sinoatrial node function in the early postoperative period (transient: 23.7%; fixed: 23.7%; p < 0.001) and on follow-up (group 1: 7.7%; group 2: 16.7%; p < 0.02). In group 2, 40 of 82 patients without arrhythmia after first intervention (cavopulmonary shunt) had an arrhythmia after the second intervention (Fontan) (49%); of 14 with an arrhythmia after the first operation, 10 (71%) had one at the second intervention (p < 0.01). In conclusion, a multistaged operative pathway to Fontan reconstruction is associated with a higher early risk of altered sinoatrial node function. The occurrence of altered sinoatrial node function after cavopulmonary shunt is itself a risk factor for arrhythmia after the Fontan operation. Longer follow-up is needed to assess the full impact of this finding.