Transcatheter and endovascular stent graft management of coarctation-related pseudoaneurysms.

OBJECTIVE: Surgical correction of congenital aortic coarctation can lead to a number of important problems including late pseudoaneurysm formation. Redo surgery has a significant risk. Endovascular stent graft repair is increasingly used but there are limited data regarding this indication. We describe the experience of two UK congenital referral centres. DESIGN: Retrospective analysis of patients treated with endovascular aortic stent grafting for late pseudoaneurysms. SETTING: Two UK congenital heart centres, Bristol Heart Institute and Leeds General Infirmary. PATIENTS: 17 patients were treated 2006-2012. This represents all patients treated with this technique. MAIN OUTCOME MEASURES: Procedural and postprocedure success and complications. RESULTS: The average time from index repair to endovascular repair of pseudoaneurysm was 24.6 years. The majority (70.6%) had patch aortoplasty as the original surgical procedure and 41.2% were not under follow-up or discharged. Stent grafting procedural success rate was 100%. Median hospital stay postprocedure was 3 days. There was no procedural mortality or immediate complication. There were four minor early and three minor late complications. Imaging follow-up was available for an average of 31.6 months (range 6-65 months). All patients have demonstrated positive remodelling of the pseudoaneurysm with no incidence of continued expansion or stent graft failure up to 5 years following implant. CONCLUSIONS: Endovascular stent graft treatment of pseudoaneurysms show promising results in a population who have a high risk of surgical re-intervention. Complication rates appear to be low and recovery is quick. Longer-term data remain essential to scrutinise stent graft performance in this situation.

Surgical correction of metacarpophalangeal valgus deformity in an alpaca.

A 1-month-old alpaca cria presented with a 13 degree valgus deformity of the left metacarpophalangeal joint. The angular limb deformity was centered on the distal metacarpal physes. Transphyseal bridging of the physes was recommended. Two 2.7 mm cortical bone screws were placed either side of the distal metacarpal physes and a figure of eight wire was placed medially around the screw heads. The screws extended through the medial metacarpus into the axial cortex of the lateral metacarpus. Seven weeks after surgery the limb was straight and the screws and wire were removed. Transphyseal bridging of the distal metacarpal physes can be effectively used for the treatment of metacarpophalangeal valgus in crias with open physes.

Myocardial metabolic changes during pediatric cardiac surgery: a randomized study of 3 cardioplegic techniques.

BACKGROUND: Blood cardioplegia and terminal warm blood cardioplegic reperfusion ("hot shot") reduce myocardial injury and improve metabolic recovery in hypoxic but not normoxic experimental models. However, there is little evidence of a benefit of either technique in pediatric clinical practice compared with crystalloid cardioplegia. METHODS: Pediatric patients undergoing cardiac surgery were randomized to receive intermittent antegrade cold crystalloid cardioplegia, cold blood cardioplegia, or cold blood cardioplegia with a hot shot. Right ventricular biopsy specimens were collected before ischemia, at the end of ischemia, and 20 minutes after reperfusion. Cellular metabolites were analyzed. In acyanotic patients postoperative serum troponin I levels were also measured at 1, 4, 12, 24, and 48 hours. RESULTS: Of 103 patients recruited, 32 (22 acyanotic and 10 cyanotic), 36 (24 acyanotic and 12 cyanotic), and 35 (25 acyanotic and 10 cyanotic), respectively, were allocated to the groups receiving cold crystalloid cardioplegia, cold blood cardioplegia, and cold blood cardioplegia with a hot shot. Cyanotic patients were younger, with longer crossclamp times. There were no significant differences in clinical outcomes between cardioplegic methods. The cardioplegic method had no overall effect in terms of adenosine triphosphate, ln(adenosine triphosphate/adenosine diphosphate), or ln(glutamate) in acyanotic patients (P =.11, P =.66, and P =.30, respectively). Also, there was no significant difference between groups in troponin I release. However, in cyanotic patients cold blood cardioplegia with a hot shot significantly reduced the decrease in adenosine triphosphate, ln(adenosine triphosphate/adenosine diphosphate), and glutamate observed at the end of ischemia and after reperfusion compared with the decrease seen in those receiving cold crystalloid cardioplegia (P =.002, P =.003, and P =.008, respectively), with cold blood cardioplegia representing an intermediate. CONCLUSIONS: For cyanotic patients (younger, with longer crossclamp times), cold blood cardioplegia with a hot shot is the best method of myocardial protection. For acyanotic patients (older, with shorter crossclamp times), cardioplegic technique is not critical.

A prospective randomized study comparing volume-standardized modified and conventional ultrafiltration in pediatric cardiac surgery.

BACKGROUND: Modified ultrafiltration has been touted as superior to conventional ultrafiltration for attenuating the consequences of hemodilution after cardiac surgery with cardiopulmonary bypass in children. We conducted a prospective randomized study to test the hypothesis that modified and conventional ultrafiltration have similar clinical effects when a standardized volume of fluid is removed. METHODS: From October 1998 to September 1999, 110 children weighing 15 kg or less (median weight 6.1 kg, median age 6.3 months) undergoing surgery with cardiopulmonary bypass for functionally biventricular congenital heart disease were randomized to conventional (n = 67) or arteriovenous modified ultrafiltration (n = 43) for hemoconcentration. The volume of fluid removed with both methods was standardized as a percentage of effective fluid balance (the sum of prime volume and volume added during cardiopulmonary bypass minus urine output): in patients weighing less than 10 kg, 50% of effective fluid balance was removed, whereas 60% was removed in patients weighing 10 to 15 kg. Hematocrit, hemodynamics, ventricular function, transfusion of blood products, and postoperative resource use were compared between groups. RESULTS: There were no significant differences between groups in age, weight, or duration of cardiopulmonary bypass. The total volume of fluid added in the prime and during bypass was greater in patients undergoing conventional ultrafiltration than in those receiving modified ultrafiltration (205 +/- 123 vs 162 +/- 74 mL/kg; P =.05), although the difference was due primarily to a greater indexed priming volume in patients having conventional ultrafiltration. There was no difference in the percentage of effective fluid balance that was removed in the 2 groups. Accordingly, the volume of ultrafiltrate was greater in patients receiving conventional than modified ultrafiltration (95 +/- 63 vs 68 +/- 28 mL/kg; P =.01). Preoperative and postoperative hematocrit levels were 35.6% +/- 6.6% and 36.3% +/- 5.6% in patients having conventional ultrafiltration and 34.4% +/- 6.7% and 38.7% +/- 7.5% in those having modified ultrafiltration. By repeated-measures analysis of variance, patients receiving modified and conventional ultrafiltration did not differ with respect to hematocrit value (P =.87), mean arterial pressure (P =.85), heart rate (P =.43), or left ventricular shortening fraction (P =.21) from baseline to the postbypass measurements. There were no differences between groups in duration of mechanical ventilation, stay in the intensive care unit, or hospitalization. CONCLUSIONS: When a standardized volume of fluid is removed, hematocrit, hemodynamics, ventricular function, requirement for blood products, and postoperative resource use do not differ between pediatric patients receiving conventional and modified ultrafiltration for hemoconcentration after cardiac surgery.

Neutrophil degranulation and complement activation during fetal cardiac bypass.

BACKGROUND: Fetal cardiac bypass results in dysfunction of the fetoplacental unit (FPU) characterized by increased placental vascular resistance and respiratory acidosis. However the mechanisms of this dysfunction are not completely understood. To test the hypothesis that complement activation and neutrophil degranulation may contribute to the placental dysfunction associated with fetal bypass, we compared placental hemodynamics, complement activation, and neutrophil degranulation among fetuses exposed to cardiac bypass with a miniaturized bypass circuit including an in-line axial flow pump (Hemopump), fetuses undergoing bypass with a conventional roller pump circuit, and control fetuses that were similarly exposed but did not undergo bypass. METHODS: Twenty-six Western Cross sheep fetuses (median 122 days gestation) were randomly assigned to undergo cardiac bypass for 30 minutes with the Hemopump circuit (n = 8), to undergo bypass for 30 minutes with the conventional (roller pump) circuit (n = 10), or to undergo identical exposure and cannulation but not bypass (n = 8, controls). Blood samples were collected to measure white cell count and differential, and C3a and lactoferrin levels prior to bypass, at the end of bypass, and 1 and 2 hours after bypass. Hemodynamics and blood gases were also monitored. RESULTS: There was a fall in white cell count over time that continued after bypass in all groups; neutrophils and lymphocytes were affected similarly. C3a levels rose significantly from prebypass to postbypass in the roller pump group (p<0.0001) but not in either of the other groups. Lactoferrin levels rose significantly from start of bypass in both bypass groups (Hemopump p = 0.01; roller pump p<0.0001) but not in controls. The elevation in lactoferrin level coincided with worsening placental gas exchange and deteriorating cardiac function. CONCLUSIONS: Complement and neutrophil activation occurred with fetal cardiac bypass but only neutrophil activation mirrored the FPU and cardiac dysfunction, suggesting that products of neutrophil activation may be important contributing factors. Improved FPU function with a bypass circuit that has less extracorporeal surface and does not require a large priming volume may be due in part to a reduction in the magnitude of this inflammatory response.

Management and outcomes of delayed sternal closure after cardiac surgery in neonates and infants.

OBJECTIVES: To investigate the efficacy, safety, and patterns of management of open sternotomy and delayed sternal closure in infants who were left with an open sternum after cardiac surgery and to assess these patterns for possible correlation with outcome. DESIGN: Retrospective chart review with statistical analysis. SETTING: Pediatric cardiac surgery service at a regional referral center based in an urban university teaching hospital. PATIENTS: All 128 patients <1 yr of age who were left with an open sternum after cardiac surgery with cardiopulmonary bypass during the 4-yr period from July, 1992 to June, 1996. INTERVENTIONS: Procedures for managing open sternotomy and delayed sternal closure were analyzed retrospectively. No interventions were undertaken for the study. MEASUREMENTS AND RESULTS: Of the 128 patients, 14 (11%) died before sternal closure; delayed sternal closure was performed in the remaining 114. Of these 114, 13 died in the early postoperative period. During sternal closure, significant increases were noted in pulmonary arterial (from 21.1+/-7.6 mm Hg to 26.1+/-6.5 mm Hg; p = .006), left atrial (from 8.4+/-3.4 mm Hg to 11.5+/-3.7 mm Hg; p < .001), and right atrial pressures (from 7.3+/-2.5 mm Hg to 9.8+/-2.5 mm Hg; p < .001). In addition, mean airway pressure (from 7.4+/-2.0 mm Hg to 8.6+/-2.4 mm Hg; p < .001) and peak inspiratory pressure (from 29.3+/-5.4 mm Hg to 31.3+/-5.6 mm Hg; p = .004) increased. Sternal wound infection occurred in one patient. CONCLUSIONS: Delayed sternal closure is an effective approach to the management of neonates and infants at risk for hemodynamic, respiratory, or hemostatic instability early after cardiac surgery. Significant changes in hemodynamics and respiratory variables occur during sternal closure, often requiring adjustment of inotropic and ventilatory management. (Crit Care Med 2000; 28: 1180-1184)

Early and intermediate outcomes after repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 85 patients.

BACKGROUND: Pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collaterals (MAPCAs) is a complex lesion with marked heterogeneity of pulmonary blood supply. Traditional management has involved staged unifocalization of pulmonary blood supply. Our approach has been to perform early 1-stage complete unifocalization in almost all patients. METHODS AND RESULTS: Since 1992, 85 patients with pulmonary atresia, VSD, and MAPCAs have undergone unifocalization (median age, 7 months). Complete 1-stage unifocalization and intracardiac repair were performed through a midline approach in 56 patients, whereas 23 underwent unifocalization in a single stage with the VSD left open, and 6 underwent staged unifocalization through sequential thoracotomies. There were 9 early deaths. During follow-up (1 to 69 months), there were 7 late deaths. Actuarial survival was 80% at 3 years. Among early survivors, actuarial survival with complete repair was 88% at 2 years. Reintervention on the neo-pulmonary arteries was performed in 24 patients. CONCLUSIONS: Early 1-stage complete unifocalization can be performed in >90% of patients with pulmonary atresia and MAPCAs, even those with absent true pulmonary arteries, and yields good functional results. Complete repair during the same operation is achieved in two thirds of patients. There remains room for improvement; actuarial survival 3 years after surgery is 80%, and there is a significant rate of reintervention. These results must be appreciated within the context of the natural history of this lesion: 65% of patients survive to 1 year of age and slightly >50% survive to 2 years even with surgical intervention.

Resection of subaortic stenosis; can a more aggressive approach be justified?

OBJECTIVES: Discrete subaortic stenosis causes left ventricular outflow tract (LVOT) obstruction and often produces aortic regurgitation (AR) which alone may precipitate surgical intervention. Conventional resection relieves the obstruction, but the recurrence rate is high, and the AR is little changed as the thick fibrous membrane which extends onto the valve leaflets remains. We studied whether an aggressive surgical approach could reduce both the severity of AR and rate of recurrence of obstruction associated with discrete subaortic stenosis, and whether this aggressive approach could be justified. METHODS: Between June 1992 and April 1996, 37 patients aged 0.5-35 years (median 7.5) underwent resection of a discrete subaortic membrane. Ten underwent re-operation for recurrent obstruction and eight followed previous ventricular septal defect closure. LVOT gradient was measured using the modified Bernoulli equation and AR was graded on a scale of 0-4 (0 = none, 4 = severe). Postoperative assessment was performed early (<7 days) and at mid-term (27.0 months; range 2-59 months). RESULTS: There was significant improvement in AR from mild/moderate to none/trivial (P = 0.019) immediately postoperatively and LVOT gradient from 66.9+/-30.4 to 15.1+/-12.2 mmHg (P < 0.0001). By stepwise logistic regression preoperative gradient correlated significantly with postoperative mild/moderate AR (P = 0.015) and LVOT gradient (P = 0.0036). Preoperative mild/moderate AR also correlated with postoperative mild/moderate AR (P = 0.034). Five patients developed complete heart block, four undergoing reoperation for recurrent obstruction, and one preoperatively had right bundle branch block from previous ventricular septal defect repair. At mid-term follow-up there was no increase in AR or LVOT gradient (14.8+/-12.8 mmHg). Early post-operative AR was the strongest predictor of late mild/moderate AR (P = 0.02). Early post-operative gradient was a weaker predictor (P = 0.04). Pre-operative and early post-operative gradient were significant predictors of late gradient (P = 0.0038; <0.0001, respectively). No patient required reoperation for recurrent obstruction; one underwent late aortic valve replacement for severe AR. CONCLUSIONS: An aggressive surgical approach to discrete subaortic stenosis produces excellent relief of obstruction and frees the valve leaflets, significantly reducing associated AR at early and mid-term follow-up with low morbidity for primary operation. Long-term follow-up is required to confirm whether this early benefit is maintained.

The use of 'pericardial hoods' for maintaining exact coronary artery geometry in the arterial switch operation with complex coronary anatomy.

OBJECTIVE: Complex coronary artery anatomy is the major risk factor for the arterial switch operation. Of the many approaches described the 'trap door' technique for coronary reimplantation is most flexible and allows safer transfer in complex arterial configurations. However, we have occasionally been concerned regarding torsion of the vessels with this approach. We therefore explored the role of trap-door augmentation with pericardial hoods to maintain exact coronary geometry during coronary transfer. METHODS: Between February 1992 and December 1997, 80 patients underwent an arterial switch procedure at our institution. Sixty-seven patients underwent direct coronary reimplantation. In ten, coronary/great vessel anatomy was considered unfavourable and the trap-door approach was adopted primarily. In two an augmented trap-door was performed as the primary procedure and in the last patient Aubert's approach was used. In five patients during rewarming, ischaemic changes were noted on the electrocardiogram and/or regional wall motion abnormalities on transoesophageal echocardiography. This prompted revision of the appropriate coronary anastomosis. In three it was considered the anastomosis was kinked due to angulation of the button; in two the coronary was overstretched. In four, revision of the anastomosis was by pericardial hood augmentation. RESULTS: In all patients there was normalization of the electrocardiogram and immediate improvement in cardiac function documented by transoesophageal echocardiography. No early or late death occurred in the pericardial hood group nor were there any readmissions for any reason. CONCLUSIONS: Pericardial augmentation of trap-door aortic anastomoses allows for the maintenance of exact coronary artery geometry during the arterial switch procedure and minimizes the risk of myocardial ischaemia. We believe it broadens the application of the arterial switch procedure to even the most complex coronary anatomy and is a useful adjunct to the other techniques of coronary transfer.

Early results of the extracardiac conduit Fontan operation.

BACKGROUND: Among the modifications of the Fontan operation, the extracardiac approach may offer the greatest potential for optimizing early postoperative ventricular and pulmonary vascular function, insofar as it can be performed with short periods of normothermic partial cardiopulmonary bypass and without cardioplegic arrest in most cases. In this study, we reviewed our experience with the extracardiac conduit Fontan operation, with a focus on early postoperative outcomes. METHODS AND RESULTS: Between July 1992 and April 1997, 51 patients (median age 4.9 years) underwent an extracardiac conduit Fontan operation. Median cardiopulmonary bypass time was 92 minutes and has decreased significantly over the course of our experience. Intracardiac procedures were performed in only 5 patients (10%), and the aorta was crossclamped in only 11 (22%). Intraoperative fenestration was performed in 24 patients (47%). There were no early deaths. Fontan failure occurred in 1 patient who was a poor candidate for the Fontan procedure. Transient supraventricular tachyarrhythmias occurred in 5 patients (10%). Median duration of chest tube drainage was 8 days. Factors significantly associated with prolonged resource use (mechanical ventilation, inotropic support, intensive care unit stay, and hospital stay) included longer bypass time and higher Fontan pressure. At a median follow-up of 1.9 years, there was 1 death from bleeding at reoperation. CONCLUSIONS: The extracardiac conduit Fontan procedure can be performed with minimal mortality and morbidity. Improved results may be related to advantages of the extracardiac approach and improved preservation of ventricular and pulmonary vascular function.

Results of 102 cases of complete repair of congenital heart defects in patients weighing 700 to 2500 grams.

BACKGROUND: Published data suggest that low birth weight is a risk factor for poor outcome in corrective surgery for many cardiac defects. Congenital heart defects in low birth weight infants are typically managed with supportive therapy or palliative operations, with definitive repair delayed. The morbidity associated with such approaches is high. METHODS: Since 1990 complete repair of congenital heart defects (other than patent ductus arteriosus) has been performed in 102 infants no larger than 2500 g (median 2100 g, range 700-2500 g), including 16 no larger than 1500 g. Defects included ventricular septal defect (n = 22), tetralogy of Fallot complexes (n = 20), transposition complexes (n = 13), aortic coarctation (n = 12), interrupted arch (n = 10), truncus arteriosus (n = 8), atrioventricular septal defect (n = 6), total anomalous pulmonary venous return (n = 5), and other (n = 6). RESULTS: Preoperative morbidity was more common among patients referred late for surgical correction. There were 10 early deaths (10%) attributable to cardiac failure (n = 4), arrhythmia (n = 1), multiorgan failure (n = 1), sepsis (n = 1), idiopathic coronary artery intimal necrosis (n = 1), foot gangrene (n = 1), and pulmonary hemorrhage (n = 1). No patient had postbypass intracerebral hemorrhage. At follow-up (median 36 months) there were 8 late deaths, and 8 patients underwent 10 reinterventions. There was no evidence of neurologic sequelae attributable to the operation. CONCLUSIONS: In general, delaying repair of congenital heart defects in low birth weight infants does not confer a benefit and is associated with higher preoperative morbidity. Complete repair of both simple and complex lesions can be achieved in such cases with good results. Growth after repair approximates the normal curve for low birth weight infants without heart disease. It is recommended that such infants, especially when they have symptoms, undergo early surgical repair rather than prolonged medical management or other forms of palliation.

Endothelin receptor blockade prevents the rise in pulmonary vascular resistance after cardiopulmonary bypass in lambs with increased pulmonary blood flow.

BACKGROUND: Children with increased pulmonary blood flow may experience morbidity as the result of increased pulmonary vascular resistance after operations in which cardiopulmonary bypass is used. Plasma levels of endothelin-1, a potent vasoactive substance implicated in pulmonary hypertension, are increased after cardiopulmonary bypass. OBJECTIVES: In a lamb model of increased pulmonary blood flow after in utero placement of an aortopulmonary shunt, we characterized the changes in pulmonary vascular resistance induced by hypothermic cardiopulmonary bypass and investigated the role of endothelin-1 and endothelin-A receptor activation in postbypass pulmonary hypertension. METHODS: In eleven 1-month-old lambs, the shunt was closed, and vascular pressures and blood flows were monitored. An infusion of a selective endothelin-A receptor blocker (PD 156707; 1.0 mg/kg/h) or drug vehicle (saline solution) was then begun 30 minutes before cardiopulmonary bypass and continued for 4 hours after bypass. The hemodynamic variables were monitored, and plasma endothelin-1 concentrations were determined before, during, and for 6 hours after cardiopulmonary bypass. RESULTS: After 90 minutes of hypothermic cardiopulmonary bypass, both pulmonary arterial pressure and pulmonary vascular resistance increased significantly in saline-treated lambs during the 6-hour study period (P <.05). In lambs pretreated with PD 156707, pulmonary arterial pressure and pulmonary vascular resistance decreased (P <. 05). After bypass, plasma endothelin-1 concentrations increased in all lambs; there was a positive correlation between postbypass pulmonary vascular resistance and plasma endothelin-1 concentrations (P <.05). CONCLUSIONS: This study suggests that endothelin-A receptor-induced pulmonary vasoconstriction mediates, in part, the rise in pulmonary vascular resistance after cardiopulmonary bypass. Endothelin-A receptor antagonists may decrease morbidity in children at risk for postbypass pulmonary hypertension. This potential therapy warrants further investigation.

Left pulmonary artery kinking caused by outflow tract dilatation after transannular patch repair of tetralogy of Fallot.

BACKGROUND: Stenosis of the branch pulmonary arteries after tetralogy of Fallot repair can result from several mechanisms. In patients with free pulmonary regurgitation and right ventricular dilatation after transannular patch repair, we have observed that the pulmonary outflow tract can dilate and elongate craniad and rotate to the left, resulting in kinking and obstruction of the previously normal left pulmonary artery. METHODS: Ten patients referred for reoperation after tetralogy repair with severe pulmonary regurgitation and right ventricular outflow tract dilatation were found to have left pulmonary artery kinking. In 8 of these patients kinking was the sole or partial cause of left pulmonary artery obstruction, whereas there was no documented obstruction in the other 2. All patients underwent right ventricular outflow tract reconstruction and left pulmonary artery repair with removal of the redundancy at the kink point. Patching alone is not an effective method of repair in this condition, because the mechanism of obstruction is not corrected and the patch material can become redundant and lead to recurrent obstruction. RESULTS: All patients underwent successful pulmonary outflow tract reconstruction. Left pulmonary artery kinking was corrected in all patients, and relief of obstruction was attained in the 8 patients with stenosis. At follow-up ranging from 9 to 58 months, no patient has evidence of recurrent left pulmonary artery stenosis. CONCLUSIONS: Left pulmonary artery kinking should be suspected at long-term follow-up after tetralogy repair in patients with significant pulmonary regurgitation and right-sided dilatation, even if previous evaluations showed no evidence of left pulmonary arterial abnormality. Because unilateral obstruction caused by kinking may lead to asymmetric pulmonary flow, it can exacerbate pulmonary regurgitation and right ventricular dilatation, in effect accelerating the processes that led to kinking in the first place. Kinking can be relieved successfully with the techniques described in this report.

Atrioventricular valve function after single patch repair of complete atrioventricular septal defect in infancy: how early should repair be attempted?

BACKGROUND: Though repair of complete atrioventricular septal defect in infancy has become routine at most centers, it is not unusual for very young infants to be managed medically because of concerns about the fragility of the atrioventricular valve tissue. METHODS: Since July 1992, seventy-two infants have undergone primary repair of complete atrioventricular septal defects at a median age of 3.9 months (40% < 3 months). A single-patch technique was used in all patients. The cleft was closed completely in 61 patients and partially (n = 10) or not at all (n = 1) in select patients at risk for valve stenosis. Left atrioventricular valve annuloplasty was performed in 18 patients. On the basis of transesophageal echocardiographic findings, 10 patients were returned to bypass for revision of the valve repair. RESULTS: There was one early death in a patient with single left papillary muscle, no early reoperations, and no new permanent arrhythmias. Only three patients had moderate left atrioventricular valve regurgitation at discharge. During a median follow-up of 24 months, there was one late death and five reoperations for left atrioventricular valve regurgitation (n = 2) and/or systemic outflow obstruction (n = 4). Follow-up left atrioventricular valve regurgitation was moderate in three patients, mild in 14, and none/trace in 54. Age had no relation to postoperative atrioventricular valve regurgitation, death, or reoperation. CONCLUSIONS: Despite concerns about fragility of valve tissue in very young patients, excellent results can be achieved with meticulous techniques. From neonates to older infants, age at repair does not influence outcome or valve function.

Truncus arteriosus with patent ductus arteriosus and normal aortic arch.

In hearts with a common arterial trunk (truncus arteriosus), there is almost always an inverse development of the aortic arch and the ductus arteriosus. Truncus with a normal aortic arch and a patent ductus is a rare echocardiographic and surgical finding. In this report, we describe 2 neonates in whom truncus arteriosus with a normal aortic arch and a medium or large patent ductus was diagnosed by preoperative echocardiography (without catheterization) and confirmed intraoperatively.

Cardiopulmonary bypass during pregnancy.

Despite the incidence of heart disease during pregnancy falling to 1.5% over the last 25 years, when a cardiac operation is required the risk is obviously greater as two lives are at risk. The risk to the mother is now similar to that for nonpregnant female patients (3% overall) but the fetal mortality remains high (19%). Cardiac operation is ill advised except in extreme emergencies during the first two trimesters as the incidence of teratogenesis is high. During the third trimester, with improvements in the outcome for premature infants with modern neonatal intensive care, delivery of the child immediately before commencing cardiopulmonary bypass is a safe option. If this is inappropriate, high-flow, high-pressure, normothermic bypass for as brief a period as possible should be used. However, although it has theoretic advantages, the benefit of pulsatile perfusion is unproven. The fetal response to cardiopulmonary bypass is bradycardia thought to be due to hypoperfusion secondary to uterine contractions, and this dysrhythmia is reversible by increasing the perfusion rate. Fetal heart rate monitoring is therefore essential to allow these manipulations. The response of the fetoplacental unit is more complex, comprising two elements: an early vasoactive response is due to prostaglandin synthesis, whereas a more profound late acidosis appears to be related to a fetal stress response. Whether these responses can be modified by changes in our approach to cardiopulmonary bypass in pregnant women remains to be proven. Finally, uterine contractions occur in response to bypass, possibly due to a dilutional effect from the stabilizing influence of progesterone. Various techniques to modify this include the administration of progesterone, beta2-agonists, and intravenous alcohol, all with some effect. Uterine monitoring is essential to allow early control of these contractions as they are associated with significant fetal loss.

Serum S100 protein: a potential marker for cerebral events during cardiopulmonary bypass.

BACKGROUND: There is no simple method to determine the incidence or severity of brain injury after a cardiac operation. A serum marker equivalent to cardiac enzymes is required. S100 protein leaks from the cerebrospinal fluid to blood after cerebral injury. We sought to determine the pattern of release after extracorporeal circulation (ECC). METHODS: Thirty-four patients without neurologic problems underwent coronary bypass using ECC. Four had carotid stenoses. Nine others underwent coronary bypass without ECC. Serum S100 levels were measured before, during, and after the operation. RESULTS: S100 was not detected before sternotomy. Postoperative levels of S100 were related to duration of perfusion (r = 0.89, p < 0.001). Patients who did not have ECC had undetectable or fractionally raised levels except in 1 who suffered a stroke. No patient in whom ECC was used suffered an event, but those with carotid stenosis had greater S100 levels. CONCLUSIONS: S100 protein leaks into blood during ECC and may reflect both cerebral injury and increased permeability of the blood brain barrier. S100 is a promising marker for cerebral injury in cardiac surgery if elevated levels can be linked with clinical outcome.

Fate of the native aorta after repair of acute type A dissection: a magnetic resonance imaging study.

OBJECTIVE: To determine late patency of the aortic false lumen and propensity for aneurysm formation after repair of type A dissection. DESIGN: Retrospective follow up study. SETTING: Regional cardiac surgical unit. PATIENTS: 28 patients after repair of type A dissection. METHODS: Magnetic resonance imaging (MRI) was performed between 6 weeks and 12 months after operation. RESULTS: A patent distal false lumen with demonstrable blood flow was found in 22 patients (78%). Only six patients had complete obliteration of the false lumen by thrombus. The conduct of operation did not influence this. Nine patients (32%) showed aneurysmal dilatation of the false lumen and three had a repeat operation. CONCLUSIONS: So-called "successful repair" of aortic dissection does not obliterate the distal false lumen. MRI is a safe and effective radiological procedure for determining patency and dilatation in the false lumen. Patients with type A dissection with blood flow in the false lumen should be studied every 6 months to look for aneurysmal dilatation.

Transmyocardial laser revascularization.

In transmyocardial laser revascularization a series of channels are created between the left ventricular cavity and the myocardium. The operation is usually performed in isolation via a left thoracotomy without cardiopulmonary bypass, but has been done in combination with coronary artery bypass grafting. Angina pectoris with coronary artery anatomy unsuitable for either angioplasty or bypass grafting is currently the most common indication for this procedure.

Myxoma of the aortic valve.

Myxomas are one of the most common cardiac tumors but usually are confined to the atria. Although described in all cardiac chambers and on all cardiac valves, only one postmortem case of an aortic valve myxoma has been published. We present the case of a young man with an aortic valve myxoma with peripheral embolization. The other pathologic conditions with which valvular myxomas can be confused are compared and discussed.