Aortic valve-preserving procedure for enlargement of the left ventricular outflow tract and mitral anulus.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
R A Jonas
Publications and source records attributed to R A Jonas.
Pathology of explanted cryopreserved allograft heart valves: comparison with aortic valves from orthotopic heart transplants.
OBJECTIVE: We sought to determine the morphology, mechanisms of deterioration, cellular viability, extracellular matrix integrity, and the role of immune responses in the dysfunction of cryopreserved aortic and pulmonic valve allografts. METHODS: We studied 33 explanted left-sided (n = 20) or right-sided (n = 13) cryopreserved human allograft heart valves explanted several hours to 9 years after operation, 14 nonimplanted allografts, and 16 aortic valves removed from transplanted allograft hearts 2 days to 4 years after operation. Analysis included gross inspection, radiography, light microscopy, electron microscopy, and immunohistochemical studies. RESULTS: Allografts implanted for more than 1 day had progressive collagen hyalinization and loss of normal structural complexity and cellularity, including endothelium and deep connective tissue cells. Inflammatory cells were generally minimal or absent in the allografts. Transmission electron microscopy of long-term cryopreserved allograft valves revealed no viable cells, focal calcification centered around dead cell remnants, and distorted but preserved collagen. In contrast, aortic valves from transplanted hearts showed remarkable structural preservation, including endothelium and abundant deep connective tissue cells; inflammatory infiltrates were generally mild and of no apparent deleterious consequence, including valves from patients who died of fatal rejection. CONCLUSIONS: Cryopreserved allografts are morphologically nonviable; their collagen is flattened but largely preserved. They are unlikely to grow, remodel, or exhibit active metabolic functions, and their usual degeneration cannot be attributed to immunologic responses. In contrast, aortic valves of transplanted hearts maintain near-normal overall architecture and cellularity and do not show apparent immunologic injury, even in the setting of fatal myocardial parenchymal rejection or graft arteriosclerosis.
Adolescent↗
Development of a double-chambered right ventricle after repair of tetralogy of Fallot.
OBJECTIVES: We sought to determine the frequency, etiology and progressive nature of midcavity obstruction in patients after primary repair of tetralogy of Fallot (TOF). BACKGROUND: Midcavity obstruction (double-chambered right ventricle [DCRV]) represents a significant portion of reoperations in patients who have had TOF repair. This group is still poorly defined. METHODS: A retrospective review of clinical, echocardiographic and catheterization data for all patients with TOF who later underwent reoperation for DCRV was performed. RESULTS: Between 1973 and 1995, 552 children <2 years of age underwent primary TOF repair (median age 6.7 months). Long-term follow-up (median 50 months) was available in 308 children. Of these, 17 children subsequently developed DCRV requiring reoperation. The median age at initial operation was 7.9 months. During a median follow-up interval of 43.2 months, murmur intensity increased in all patients, and the average subpulmonary gradient at catheterization increased from 24+/-10 to 80+/-27 mm Hg in seven children (p = 0.002) and at Doppler echocardiography from 14+/-16 to 89+/-18 mm Hg in five children (p = 0.002). Before reoperation, 6 of the 17 children were symptomatic. During the operation (median age 55.4 months), obstruction was relieved by incision of hypertrophied anomalous muscle bundles in all 17 patients, with prominent fibrosis noted in 8 patients. Excessive septal and parietal hypertrophy was noted in one child. No new transannular patches were required. Recurrent obstruction has reappeared in 3 of these 17 children during follow-up. CONCLUSIONS: DCRV is a medium-term complication of TOF repair in infants, with a minimal incidence of 3.1% (95% CI 1.8% to 4.9%). The condition is progressive and is due to anomalous muscle bundle hypertrophy or fibrosis, or both, which may represent displaced insertion of a moderator band. Further reobstruction does occur; continued careful follow-up is therefore essential.
Disease Progression↗
Near-infrared spectrophotometry of the brain in cardiovascular surgery.
Neuropsychological and neurological deficits are still major causes of mortality and morbidity after cardiac operations and are thought to be caused by embolism and cerebral hypoxia. Near-infrared spectrophotometry (NIRS) is a promising method for non-invasive monitoring of cerebral oxygenation and hemodynamics. Different devices provide information on changes of oxygenated (HbO2) and deoxygenated hemoglobin (Hb), oxidized cytochrome aa3 (CytOx) or regional oxygen saturation (rSO2). NIRS has been applied to patients during adult and pediatric cardiovascular surgery with and without deep hypothermic circulatory arrest (DHCA). In most of the studies, significant changes in cerebral oxygenation were detected by NIRS. NIRS measurements were influenced by the cerebral oxygen metabolism and the operative management. However, clinical, experimental, and theoretical issues raise doubts as to the clinical relevance of the hemoglobin saturation (HbO2, Hb, rSO2 signals) during hypothermia and alkalosis, because the oxygen affinity of hemoglobin increases and a high saturation might simply reflect the inadequate oxygen transport into cells. In contrast, recent experiments have proved a high correlation between the CytOx signal and the MRS parameters nucleoside triphosphate and phosphocreatine. Histological damage was significantly related to the lowest CytOx value; in a clinical study it predicted impaired neuropsychological outcome. Therefore, the CytOx signal is of great interest for future studies. NIRS must prove its ability to diagnose cerebral hypoxia consistently during cardiac surgery in a large patient study before this method is brought into routine clinical practice. Absolute quantification and definitions of critical oxygenation margins will be helpful for this goal.
Adult↗
Myocardial protection for neonates and infants.
This report reviews developmental differences between mature and immature myocardium. These differences, which are structural, biochemical, and functional, probably explain the differences which are observed between mature and immature myocardium with respect to resistance to ischemia. Although there are some clinical reports and also laboratory reports suggesting that immature myocardium ist more susceptible to ischemic injury than mature myocardium, it is our impression at Children's Hospital, Boston, that immature myocardium is in fact more resistant to ischemia. A decrease in cardiac output is frequently seen after cardiac surgery though it per se is rarely a cause of death. Factors which exacerbate postoperative low cardiac output include mechanical factors such as distention and retraction, injury to coronary artery branches or direct injury to the myocardium with a ventriculostomy, as well as various perfusion and reperfusion factors such as pH. A recently completed prospective clinical trial at our hospital has revealed that cardiac output is consistently higher with pH stat relative to alpha stat. The ideal recipe for cardioplegia for immature myocardium remains poorly defined. The age at which the transition occurs to mature myocardium also remains to be defined in humans.
Aging↗
Optimal pH strategy for cardiopulmonary bypass in neonates, infants and children.
Explore the source record for details and available documents.
Athetosis↗
An institutional experience with second- and third-stage palliative procedures for hypoplastic left heart syndrome: the impact of the bidirectional cavopulmonary shunt.
OBJECTIVES: The aim of this study was to perform a retrospective analysis of an institutional experience with a consecutive series of patients with post-stage I palliation for hypoplastic left heart syndrome (HLHS). BACKGROUND: In a recent review of 212 consecutive patients who underwent stage I operations for HLHS at our institution between 1983 and 1993, we identified risk factors related to stage I mortality. We sought to examine the outcome for these patients at subsequent palliative procedures. METHODS: All patients who underwent stage I reconstruction between January 1983 and June 1993 and also underwent subsequent palliation at our institution were included. Seventy patients underwent palliative procedures and two underwent heart transplantation. Patient-specific factors and features of the stage II operation were analyzed for impact on stage II mortality and actuarial survival. RESULTS: The only independent risk factor for stage II mortality was the performance of a nonfenestrated Fontan operation (p < 0.001). There were nine in-hospital deaths (69%) in the 13 patients undergoing the nonfenestrated Fontan procedure at stage II. Fifty patients underwent intermediate superior vena cava to pulmonary artery anastomosis at stage II, with 4 (8%) early deaths. Pulmonary artery augmentation was performed in 19 patients (38%) at stage II, without increased operative risk. Hypoplastic left heart syndrome anatomic subtype did not influence stage II mortality. The modified fenestrated Fontan procedure has been performed as a third stage in 32 patients whose median age was 28.7 months, with one early death at a median follow-up of 24.5 months. CONCLUSIONS: A second-stage bidirectional cavopulmonary anastomosis for HLHS reduces second-stage mortality and improves intermediate survival. The modified fenestrated Fontan operation may then be performed as a final palliative stage with low operative risk.
Child, Preschool↗
Transcatheter fenestration dilation and/or creation in postoperative Fontan patients.
There are very few therapeutic options for severely symptomatic Fontan patients after spontaneous complete or virtual fenestration closure. Its reopening in 14 such patients led to dramatic hemodynamic improvement in most. The clinical experience with transcatheter fenestration creation and/or dilation in symptomatic Fontan patients is reported demonstrating feasibility, safety, and a novel management option for these patients.
Adolescent↗
Evaluation of a pulsatile pediatric ventricular assist device in an acute right heart failure model.
BACKGROUND: The development of pulsatile ventricular assist devices for children has been limited mainly by size constraints. The purpose of this study was to evaluate the MEDOS trileaflet-valved, pulsatile, pediatric right ventricular assist device (stroke volume = 9 mL) in a neonatal lamb model of acute right ventricular failure. METHODS: Right ventricular failure was induced in ten 3-week-old lambs (8.6 kg) by right ventriculotomy and disruption of the tricuspid valve. Control group 1 (n = 5) had no mechanical support whereas experimental group 2 (n = 5) had right ventricular assist device support for 6 hours. The following hemodynamic parameters were measured in all animals: heart rate and right atrial, pulmonary arterial, left atrial, and systemic arterial pressures. Cardiac output was measured by an electromagnetic flow probe placed on the pulmonary artery. RESULTS: All results are expressed as mean +/- standard deviation and analyzed by Student's t test. A p value less than 0.05 was considered statistically significant. Base-line measurements were not significantly different between groups and included systemic arterial pressure, 80.6 +/- 12.7 mm Hg; right atrial pressure, 4.6 +/- 1.6 mm Hg; mean pulmonary arterial pressure, 15.6 +/- 4.2 mm Hg; left atrial pressure, 4.8 +/- 0.8 mm Hg; and cardiac output, 1.4 +/- 0.2 L/min. Right ventricular injury produced hemodynamics compatible with right ventricular failure in both groups: mean systemic arterial pressure, 38.8 +/- 10.4 mm Hg; right atrial pressure, 16.8 +/- 2.3 mm Hg; left atrial pressure, 1.4 +/- 0.5 mm Hg; and cardiac output, 0.6 +/- 0.1 L/min. All group 1 animals died at a mean of 71.4 +/- 9.4 minutes after the operation. All group 2 animals survived the duration of study. Hemodynamic parameters were recorded at 2, 4, and 6 hours on and off pump, and were significantly improved at all time points: mean systemic arterial pressure, 68.0 +/- 13.0 mm Hg; right atrial pressure, 8.2 +/- 2.3 mm Hg; left atrial pressure, 6.4 +/- 2.1 mm Hg; and cardiac output, 1.0 +/- 0.2 L/min. CONCLUSIONS: The results demonstrate the successful creation of a right ventricular failure model and its salvage by a miniaturized, pulsatile right ventricular assist device. The small size of this device makes its use possible even in small neonates.
Acute Disease↗
Perioperative effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants.
OBJECTIVES: In a randomized, single-center trial, we compared perioperative outcomes in infants undergoing cardiac operations after use of the alpha-stat versus pH-stat strategy during deep hypothermic cardiopulmonary bypass. METHODS: Admission criteria included reparative cardiac surgery, age less than 9 months, birth weight 2.25 kg or more, and absence of associated congenital or acquired extracardiac disorders. RESULTS: Among the 182 infants in the study, diagnoses included D-transposition of the great arteries (n = 92), tetralogy of Fallot (n = 50), tetralogy of Fallot with pulmonary atresia (n = 6), ventricular septal defect (n = 20), truncus arteriosus (n = 8), complete atrioventricular canal (n = 4), and total anomalous pulmonary venous return (n = 2). Ninety patients were assigned to alpha-stat and 92 to pH-stat strategy. Early death occurred in four infants (2%), all in the alpha-stat group (p = 0.058). Postoperative electroencephalographic seizures occurred in five of 57 patients (9%) assigned to alpha-stat and one of 59 patients (2%) assigned to pH-stat strategy (p = 0.11). Clinical seizures occurred in four infants in the alpha-stat group (4%) and two infants in the pH-stat group (2%) (p = 0.44). First electroencephalographic activity returned sooner among infants randomized to pH-stat strategy (p = 0.03). Within the homogeneous D-transposition subgroup, those assigned to pH-stat tended to have a higher cardiac index despite a lower requirement for inotropic agents; less frequent postoperative acidosis (p = 0.02) and hypotension (p = 0.05); and shorter duration of mechanical ventilation (p = 0.01) and intensive care unit stay (p = 0.01). CONCLUSIONS: Use of the pH-stat strategy in infants undergoing deep hypothermic cardiopulmonary bypass was associated with lower postoperative morbidity, shorter recovery time to first electroencephalographic activity, and, in patients with D-transposition, shorter duration of intubation and intensive care unit stay. These data challenge the notion that alpha-stat management is a superior strategy for organ protection during reparative operations in infants using deep hypothermic cardiopulmonary bypass.
Acid-Base Equilibrium↗
The limits of detectable cerebral perfusion by transcranial Doppler sonography in neonates undergoing deep hypothermic low-flow cardiopulmonary bypass.
OBJECTIVE: Neurologic morbidity including seizures, abnormal neurologic function, and delayed psychomotor development continue to be significant problems for some patients undergoing operations for congenital heart disease, particularly for those subjected to deep hypothermic circulatory arrest. The technique of low-flow cardiopulmonary bypass has been advocated to decrease the incidence of neurologic sequelae. Our study examined the limits of detectable blood flow in the middle cerebral artery during low-flow cardiopulmonary bypass in 28 neonates undergoing the arterial switch procedure. METHODS: Cerebral blood flow velocity was measured noninvasively in the M1 segment of the middle cerebral artery with a 2 MHz range-gated pulsed-wave transcranial Doppler sonographic probe that was placed over the left temporal window. As part of the initiation of a planned period of deep hypothermic circulatory arrest, the cardiopulmonary bypass flow rate was decreased in stages to five low-flow rates (50, 40, 30, 20, and 10 ml/kg per minute). After a period of stabilization, cerebral blood flow velocities were recorded at each of the five low-flow rates and reported as a percentage of baseline. RESULTS: All 28 neonates had detectable perfusion in the middle cerebral artery at flow rates of 30 ml/kg per minute or higher. At flows of 20 and 10 ml/kg per minute, one and eight, respectively, of the 28 neonates had no detectable perfusion in the middle cerebral artery. CONCLUSIONS: Our data show that cerebral perfusion can be detected by transcranial Doppler sonography in the middle cerebral artery in some neonates at bypass pump flows as low as 10 ml/kg per minute. However, when transcranial Doppler sonography was used in our patient population, a minimum bypass flow rate of 30 ml/kg per minute was needed to detect cerebral perfusion in all neonates.
Blood Flow Velocity↗
Fontan operation in five hundred consecutive patients: factors influencing early and late outcome.
OBJECTIVES: The purpose of this study was to review a large, evolving, single-center experience with the Fontan operation and to determine risk factors influencing early and late outcome. METHODS: The first 500 patients undergoing modifications of the Fontan operation at our institution were identified. Perioperative variables were recorded and a cross-sectional review of survivors was undertaken. RESULTS: The incidence of early failure decreased from 27.1% in the first quartile of the experience to 7.5% in the last quartile. In a multivariate model, the following variables were associated with an increased probability of early failure: a mean preoperative pulmonary artery pressure of 19 mm Hg or more (p < 0.001), younger age at operation (p = 0.001), heterotaxy syndrome (p = 0.03), a right-sided tricuspid valve as the only systemic atrioventricular valve (p = 0.001), pulmonary artery distortion (p = 0.04), an atriopulmonary connection originating at the right atrial body or appendage (p = 0.001), the absence of a baffle fenestration (p = 0.002), and longer cardiopulmonary bypass time (p = 0.001). An increased probability of late failure was associated with the presence of a pacemaker before the Fontan operation (p < 0.001). A morphologically left ventricle with normally related great arteries or a single right ventricle (excluding heterotaxy syndrome and hypoplastic left heart syndrome) were associated with a decreased probability of late failure (p = 0.003). CONCLUSIONS: These analyses indicate that early failure has declined over the study period and that this decline is related in part to procedural modifications. A continuing late hazard phase is associated with few patient-related variables and does not appear related to procedural variables.
Child↗
Delayed sternal closure after cardiac operations in a pediatric population.
OBJECTIVE: The purpose of this study was to assess morbidity and mortality associated with delayed sternal closure after pediatric cardiac operations. METHODS: Hospital records were reviewed of all patients with an open sternum after a cardiac operation at Children's Hospital, Boston, from January 1992 to December 1995. RESULTS: A total of 178 patients had delayed sternal closure with an overall mortality rate of 19%. The most common diagnosis of patients with delayed sternal closure was hypoplastic left heart syndrome (29%). Although myocardial distention or chest wall edema (n = 47) was a common indication to delay sternal closure, in many patients (n = 47) the sternum was left open electively to avoid postoperative cardiac or respiratory compromise. Successful sternal closure was achieved in 158 patients (89%) at a mean of 3.4 +/- 1.8 days after opening. There were significant increases in left atrial pressure (7.7 +/- 3.4 to 9.8 +/- 4.1 mm Hg, p = 0.00001) and right atrial pressure (8 +/- 3.2 to 10.1 +/- 3.3 mm Hg, p = 0.00001) with sternal closure. There was a small but statistically significant drop in pH (7.44 +/- 0.05 to 7.41 +/- 0.08, p < 0.0001) during sternal closure. The peak inspiratory pressure, delivered breaths per minute, and fraction of inspired oxygen all significantly increased during sternal closure. Clinical evidence of surgical site infection occurred in 12 (6.7%) of the patients with delayed sternal closure; mediastinitis developed in 7 (3.9%) patients. CONCLUSIONS: Although delayed sternal closure after complex operations for congenital heart disease is often necessary in the operating room because of edema, unstable hemodynamic conditions, or bleeding, it can also be used electively to aid in hemodynamic and respiratory stability in the initial postoperative period. Our review supports a low morbidity associated with delayed sternal closure in a pediatric population.
Bandages↗
Clinical course and hemodynamic observations after supraannular mitral valve replacement in infants and children.
OBJECTIVES: We report the clinical course and unique hemodynamic findings after placement of a supraannular mitral valve prosthesis. BACKGROUND: Children with symptomatic mitral valve disease whose annulus is too small for the smallest prosthesis are difficult to manage. One option is valve replacement with a prosthesis positioned entirely within the left atrium (LA). METHODS: We reviewed 17 patients (median age 10 months) with symptomatic mitral valve disease who underwent placement of a supraannular valve prosthesis between 1980 and 1994. RESULTS: The actuarial survival rates were 88% at 1 month and 71%, 62% and 53% at 1, 2 and 10 years, respectively. Preoperative hemodynamic data (mean +/- SD)) compared with those after placement of the supraannular mitral prosthesis were as follows: "a" wave to left ventricular end-diastolic pressure gradient 17 +/- 5 versus 4 +/- 4 mm Hg (p = 0.003), mean LA pressure 25 +/- 6 versus 20 +/- 6 mm Hg (p = 0.07), "a" wave 30 +/- 6 versus 19 +/- 5 mm Hg (p = 0.006), "v" wave 28 +/- 5 versus 30 +/- 9 mm Hg (p = 0.31), mean pulmonary artery pressure 54 +/- 19 versus 42 +/- 15 mm Hg (p = 0.07) and left ventricular end-diastolic pressure 14 +/- 5 versus 16 +/- 4 mm Hg (p = 0.12). CONCLUSIONS: Supraannular mitral valve replacement provides relief of mitral stenosis or mitral regurgitation. However, LA to left ventricular early diastolic gradients with large atrial "v" waves contribute to elevated mean LA pressures in the absence of prosthetic valve obstruction or regurgitation. As a result of this unexpected finding, associated left heart obstructive lesions and pulmonary and left ventricular end-diastolic hypertension, the outlook remains poor.
Child, Preschool↗
Evaluation of a staged treatment protocol for rapid automatic junctional tachycardia after operation for congenital heart disease.
OBJECTIVES: This study sought to 1) develop an efficient treatment protocol for postoperative automatic junctional tachycardia (JT) using conventional drugs and techniques, and 2) identify clinical features associated with this disorder by analyzing a large study group. BACKGROUND: Postoperative JT is a transient arrhythmia that may be fatal after operation for congenital cardiac defects. Its precise cause is unknown. A variety of palliative treatments have evolved, but because of a low incidence of JT, large studies of the most efficient therapeutic sequence are lacking. METHODS: A protocol for rapid JT (>170 beats/min) was adopted in 1986, and was tested in 71 children between 1986 and 1994. Staged therapy involved 1) a reduction of catecholamines; 2) correction of fever; 3) atrial pacing to restore synchrony; 4) digoxin; 5) phenytoin or propranolol or verapamil; 6) procainamide or hypothermia; and 7) combined procainamide and hypothermia. Effective therapy was defined as a sustained reduction of JT rate <170 beats/min within 2 h. Clinical profiles of the study group were contrasted with all patients without JT from this same era to identify features associated with JT. RESULTS: Of the multiple treatment stages, only correction of fever and combined procainamide and hypothermia appeared to be efficacious. By refining the protocol to eliminate nonproductive stages, the time to JT control was significantly shortened for the last 30 patients. Treatment was ultimately successful in 70 of 71 children. Postoperative JT was strongly associated with young age, transient atrioventricular block and operations involving ventricular septal defect closure. CONCLUSIONS: A staged approach to therapy, with emphasis on combined hypothermia and procainamide in difficult cases, appears to be an effective management strategy for postoperative JT. These results may also serve as comparison data for evaluation of newer and promising JT options, such as intravenous amiodarone. Trauma to conduction tissue may play a central role in the etiology of this disorder.
Adolescent↗
Anomalous origin of left coronary artery from pulmonary artery: recovery of left ventricular function after dual coronary repair.
OBJECTIVES: We reviewed our institutional experience with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) after dual coronary repair to assess preoperative variables predictive of outcome, the time course for postoperative recovery of cardiac function, the short- and long-term complications and our experience with left ventricular assist devices (LVAD) in these patients. BACKGROUND: Outcome after surgical repair of ALCAPA remains incompletely defined. METHODS: The surgical records and echocardiograms of 42 patients were reviewed. Left ventricular function was assessed by fractional shortening z-score (FSz) and stress-velocity index. RESULTS: The overall survival rate was 86%. All six patients who died were < 1 year old and died within 3 days of the operation. More severe preoperative mitral regurgitation (MR) was associated with increased mortality, but age, body surface area, preoperative FSz and end-diastolic dimension were not. We used an LVAD for 7 of 28 patients who underwent repair for ALCAPA since its introduction at our institution, with a survival of 5 of 7 patients. The degree of MR improved in 62% of patients and remained unchanged in 38%. Complications included supravalvar pulmonary stenosis (16 of 21 patients) and baffle leaks (11 of 21 patients) with the intrapulmonary baffling technique. Supravalvar pulmonary stenosis developed in 1 of 11 patients after direct coronary reimplantation. Left ventricular function became normalized in all 28 patients with follow-up past 1 year, regardless of preoperative FSz. Of 13 patients who underwent serial postoperative echocardiography, the average time to normalization of function was 2 to 7 months. CONCLUSIONS: The degree of preoperative MR was predictive of outcome, whereas the severity of preoperative cardiac dysfunction and ventricular dilation were not. Mild and moderate MR tended to improve without mitral valvuloplasty. Complete recovery from myocardial dysfunction is expected after dual coronary repair of ALCAPA.
Adolescent↗
Intermittent whole-body perfusion with "somatoplegia' versus blood perfusate to extend duration of circulatory arrest.
BACKGROUND: Continuous whole-body perfusion for > 3 hours with a cold asanguineous blood substitute, hypothermosol (HTS) solution, has been reported to preserve organ function. We used this solution in a survival animal model to evaluate its possible application in extending the safe duration of deep hypothermic circulatory arrest (DHCA). METHODS AND RESULTS: Fifteen piglets were placed on cardiopulmonary bypass (CPB), were cooled to a nasopharyngeal temperature of 15 degrees C, and underwent 100 minutes of DHCA. Control animals (group C, n = 5) had uninterrupted DHCA, group HTS animals were perfused with maintenance HTS for 5 minutes every 25 minutes during DHCA (n = 5), and group B animals were intermittently perfused as for group HTS with the blood in the bypass circuit (n = 5). Cerebral oxygenation was assessed with near-infrared spectroscopy throughout CPB and DHCA. Animals were allowed to recover after CPB and underwent daily neurobehavioral evaluation by the neurological deficit score (NDS: 0, normal; 500, brain death) and overall performance categories (OPC: 1, normal; 5, brain death). Blood samples were drawn on postoperative day (POD) 1 for selected biochemistry analysis. On POD 4, the brain of each animal was perfusion-fixed for histological evaluation, and a neurohistological score (NHS: 0, normal; 5+, necrosis) was assigned for the degree of neuronal injury. All animals except one from group HTS survived surgery. Mean perfusion pressures were significantly elevated in group B compared with group C and group HTS during the rewarming phase (P < .05). The HbO2 signal increased in all groups during the cooling phase of CPB and remained significantly above baseline only in group B during DHCA (P < .05). SGOT, LDH, ALP, and CPK levels on POD 1 were elevated above baseline in all groups. The increase in SGOT and ALP was significantly greater in group HTS than in the other groups (P < .02). The NDS was lower in group B on each postoperative evaluation, being significant relative to group C and group HTS on POD 1 (P < .05) and significantly lower than group C on POD 2 (P < .05). The OPC score was significantly lower in group B than in group C and group HTS on POD 2 (P < .05) and significantly lower than in group C on PODs 3 and 4 (P < .05). The NHS was lower in group B than in the other 2 groups, being significant relative to group C in the neocortex (P < .007). CONCLUSIONS: Intermittent whole-body asanguineous perfusion with hypothermosol solution does not extend cerebral protection in a porcine survivor model of DHCA. Neurobehavioral and histological outcomes are improved in animals receiving intermittent blood perfusion during prolonged DHCA.
Animals↗
Diagnosis and management of agenesis of the right lung and left pulmonary artery sling.
The diagnostic, developmental, and surgical aspects of left pulmonary artery sling associated with right lung agenesis in 3 patients are described. Cardiac catheterization may be avoided by the combined use of echocardiography and magnetic resonance imaging and/or computed tomography.
Abnormalities, Multiple↗