Effects of dexmedetomidine on kidney and brain tissue microcirculation and histology in ovine cardiopulmonary bypass: a randomised controlled trial.

Cardiac surgery requiring cardiopulmonary bypass is associated with postoperative acute kidney injury and neurocognitive disorders, including delirium. Intra-operative inflammation and/or impaired tissue perfusion/oxygenation are thought to be contributors to these outcomes. It has been hypothesised that these problems may be ameliorated by the highly selective α2 -agonist, dexmedetomidine. We tested the effects of dexmedetomidine on renal and cerebral microcirculatory tissue perfusion, oxygenation and histology in a clinically relevant ovine model. Sixteen sheep were studied while conscious, after induction of anaesthesia and during 2 h of cardiopulmonary bypass. Eight sheep were allocated randomly to receive an intravenous infusion of dexmedetomidine (0.4-0.8 µg.kg-1 .h-1 ) from induction of anaesthesia to the end of cardiopulmonary bypass, and eight to receive an equivalent volume of matched placebo (0.9% sodium chloride). Commencement of cardiopulmonary bypass decreased renal medullary tissue oxygenation in the placebo group (mean (95%CI) 5.96 (4.24-7.23) to 1.56 (0.84-2.09) kPa, p = 0.001), with similar hypoxic levels observed in the dexmedetomidine group (6.33 (5.33-7.07) to 1.51 (0.33-2.39) kPa, p = 0.002). While no differences in kidney function (i.e. reduced creatinine clearance) were evident, a greater incidence of histological renal tubular injury was observed in sheep receiving dexmedetomidine (7/8 sheep) compared with placebo (2/8 sheep), p = 0.041. Graded on a semi-quantitative scale (0-3), median (IQR [range]) severity of histological renal tubular injury was higher in the dexmedetomidine group compared with placebo (1.5 (1-2 [0-3]) vs. 0 (0-0.3 [0-1]) respectively, p = 0.013). There was no difference in cerebral tissue microglial activation (neuroinflammation) between the groups. Dexmedetomidine did not reduce renal medullary hypoxia or cerebral neuroinflammation in sheep undergoing cardiopulmonary bypass.

Initial results of primary device closure of large muscular ventricular septal defects in early infancy using perventricular access.

OBJECTIVES: To report our experience with the use of the Amplatzer muscular ventricular septal defect (VSD) occluder, using direct right ventricle free wall puncture for primary closure of muscular VSDs in infants. BACKGROUND: Young infants with heart failure due to large or multiple muscular VSDs often require intervention at a stage when percutaneous device closure is impractical due to delivery system limitations. There are considerable benefits to avoiding bypass in these infants. METHODS: Patients with suitable muscular VSDs, considered too small for transvenous closure, underwent periventricular muscular VSD closure under transesophageal echo (TEE) guidance. RESULTS: Eight infants underwent the procedure. The median age was 14 weeks (2-41) with median weight of 4 kg (3-6.6). Four patients had additional VSDs and one patient had previous repair of coarctation. One patient had dextrocardia and severe left ventricular impairment due to an associated cardiomyopathy. The median VSD size was 8 mm (range, 4-10 mm). A single device (6-12 mm) was deployed in each patient, the size chosen being 1-2 mm larger than the TEE measurement. Two patients had subsequent pulmonary artery banding, with absorbable bands, because of moderate residual shunting through additional VSDs. The latest echo study at a median of 7.2 weeks (0.5-66) post device implantation revealed no patients with a hemodynamically significant shunt. CONCLUSION: Perventricular muscular VSD closure can be safely and effectively undertaken in small infants with suitable muscular defects, and this strategy can avoid the need for bypass.

Renal haemodynamics and oxygenation during and after cardiac surgery and cardiopulmonary bypass.

Acute kidney injury (AKI) is a common complication following cardiac surgery performed on cardiopulmonary bypass (CPB) and has important implications for prognosis. The aetiology of cardiac surgery-associated AKI is complex, but renal hypoxia, particularly in the medulla, is thought to play at least some role. There is strong evidence from studies in experimental animals, clinical observations and computational models that medullary ischaemia and hypoxia occur during CPB. There are no validated methods to monitor or improve renal oxygenation during CPB, and thus possibly decrease the risk of AKI. Attempts to reduce the incidence of AKI by early transfusion to ameliorate intra-operative anaemia, refinement of protocols for cooling and rewarming on bypass, optimization of pump flow and arterial pressure, or the use of pulsatile flow, have not been successful to date. This may in part reflect the complexity of renal oxygenation, which may limit the effectiveness of individual interventions. We propose a multi-disciplinary pathway for translation comprising three components. Firstly, large-animal models of CPB to continuously monitor both whole kidney and regional kidney perfusion and oxygenation. Secondly, computational models to obtain information that can be used to interpret the data and develop rational interventions. Thirdly, clinically feasible non-invasive methods to continuously monitor renal oxygenation in the operating theatre and to identify patients at risk of AKI. In this review, we outline the recent progress on each of these fronts.

Transatrial-transpulmonary tetralogy of Fallot repair is effective in the presence of anomalous coronary arteries.

OBJECTIVES: The study's object was to analyze the outcomes of transatrial-transpulmonary repair in children with tetralogy of Fallot and anomalous coronary artery crossing the right ventricular outflow tract. METHODS: The transatrial-transpulmonary approach was used in 611 consecutive repairs, 36 (5.9%) of which were associated with a surgically relevant coronary artery anomaly. The median age and weight of the patients at repair were 23 months (2.8-170 months) and 9.9 kg (5.2-41 kg), respectively. Anomalies included left anterior descending coronary artery from right coronary artery or single right coronary artery (n = 22), right coronary artery from left coronary artery or left anterior descending coronary artery (n = 8), and large right coronary artery conal branch (n = 6). Diagnosis was established before the operation in 25 of 36 cases by angiography (n = 24) or echocardiography (n = 1). The approach was successful in 34 cases, in 25 of which placement of a limited transannular patch was necessary. Two patients had a right ventricle-pulmonary artery conduit as a result of proximity of the coronary branch to the pulmonary arterial anulus and inability to adequately relieve the right ventricular outflow tract obstruction. RESULTS: There have been no early or late deaths. Mean right ventricle-pulmonary artery gradient at last follow-up was 19 mm Hg (95% confidence interval 14.5-24 mm Hg), compared with 15 mm Hg (95% confidence interval 12.5-17.5 mm Hg) for patients with normal coronary arteries (P = .3). Actuarial freedom from reoperation at 120 months was 96.5% (95% confidence interval 79.8%-99.5%) and was also similar between patients with and without coronary artery abnormalities (P = .92). CONCLUSIONS: Surgically important coronary anomalies in tetralogy of Fallot can be dealt with through the transatrial-transpulmonary approach in most cases without major alterations in technique. Outcomes are similar to those of other patients with tetralogy of Fallot. The presence of anomalous coronary arteries does not impart incremental risk after this surgical strategy.

Retransplantation in heart-lung recipients with obliterative bronchiolitis.

Obliterative bronchiolitis remains the leading cause of morbidity and mortality in long-term survivors after heart-lung transplantation. Despite enhanced immunosuppressive therapy, a significant number of patients progress to end-stage respiratory failure, leaving retransplantation as the only potential therapeutic option. Between October 1986 and August 1990, 25 heart-lung recipients (mean age 22 +/- 2 years) underwent repeat heart-lung transplantation at an average of 21 months after their first procedure. Twenty-one patients (83%) were ventilator dependent at the time of retransplantation. The Kaplan-Meier survival at 1, 6, 12, and 24 months was 52%, 33%, 25%, and 25%, respectively. Postoperative complications included bleeding, multisystem organ failure, and infection. Obliterative bronchiolitis resulted in death or graft failure in three patients between 12 and 36 months after the second transplantation. Five patients were currently alive at the time this article was written, with a median follow-up of 54 months. Three were in New York Heart Association class I, and two had obliterative bronchiolitis with class III symptoms. Recently, we investigated the role of single lung retransplantation in nine heart-lung recipients (mean age 23 +/- 3 years). The mean interval between procedures was 36 months, and eight patients (88%) were ventilator dependent. The Kaplan-Meier survival at 1, 6, 12, and 24 months was 89%, 67%, 67%, and 50%, respectively. We observed significantly less perioperative morbidity in this group. Five patients were alive (median follow-up 20 months); four were in New York Heart Association class I or II, and one was in New York Heart Association class III with recurrent obliterative bronchiolitis. We did not have enough patients to perform multivariate survival analysis. Survival curve comparisons with the use of the Wilcoxon test did show that the absence of performed antibodies in the recipient (panel reactive antibody frequency less than 10%) was associated with significantly improved survival after retransplantation. We also noted trends for improved survival in patients who had retransplantation at least 18 months after their original transplantation and in patients with negative preoperative sputum cultures. Retransplantation is a high-risk procedure that can result in rehabilitation in otherwise incapacitated patients. Single lung retransplantation appears to be the preferred option in carefully selected patients.

Effect of preoperative supplementation with alpha-tocopherol and ascorbic acid on myocardial injury in patients undergoing cardiac operations.

Augmentation of antioxidant defenses may help protect tissues against ischemia-reperfusion injury associated with operations involving cardiopulmonary bypass. In this study we examined the effect of pretreating patients with alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C) or placebo on injury to the myocardium. Seventy-six subjects undergoing elective coronary artery bypass grafting participated in a prospective, double-blind, placebo-controlled randomized trial, receiving either placebo or both 750 IU dl-alpha-tocopherol per day for 7 to 10 days and 1 gm ascorbic acid 12 hours before the operation. Plasma alpha-tocopherol concentrations, raised fourfold by supplementation, fell by 70% after the operation in the supplemented group and to negligible levels in the placebo group. There were no significant differences between the groups with respect to release of creatine kinase MB isoenzyme over 72 hours, nor in the reduction of the myocardial perfusion defect determined by thallium 201 uptake. Electrocardiography provided no evidence of a benefit from antioxidant supplementation. Thus the supplementation regimen prevented the depletion of the primary lipid soluble antioxidant in plasma, but provided no measurable reduction in myocardial injury after the operation.

Excellent long-term functional outcome after an operation for anomalous left coronary artery from the pulmonary artery.

OBJECTIVE: The aim of this study was to review the results of operations for anomalous left coronary artery from the pulmonary artery and the late outcome for exercise capacity, left ventricular function, and mitral regurgitation. METHODS: Twenty-one patients underwent operations over an 18-year period (median age, 9 months; range, 6 weeks-26 years) with a median follow-up of 6.5 years (range, 2 months-18 years). In addition to clinical and echocardiographic follow-up, patients at our institution were also investigated with radionuclide scans (n = 10) and treadmill exercise testing (n = 8). RESULTS: There were no operative or late deaths (0%; 95% confidence interval [CI], 0% and 16%). Five patients required support with a left ventricular assist device. Eighteen patients are currently in New York Heart Association class I, and 3 patients are mildly symptomatic. On nuclear gated scan at a mean of 6 years after the operation, the left ventricular ejection fraction was 64% (SD, 3%) at rest and increased to 74% (SD = 3%) on exercise (95% CI for the difference, 6%, 14%; P =.001). Treadmill endurance was normal for age (9.8-14.5 minutes) in those old enough to exercise. On echocardiography (n = 18), the current fractional shortening was 34% (SD, 4%) in the 15 patients with normal or only mildly abnormal ventricular septal motion. Three patients have undergone mitral valve operations. The left ventricular end-diastolic dimension fell from 48 mm (SD, 5.8 mm) before surgery to 35.1 mm (SD, 5.2 mm) at 1 year after the operation, and the fractional shortening increased over the first year from 19.6% (SD, 9.3%) to 32.8% (SD, 5.9%; both P <.001). CONCLUSIONS: Long-term clinical outcome and left ventricular function are good, despite severe left ventricular dysfunction at presentation.

Heterotopic heart transplantation for elevated pulmonary vascular resistance in pediatric patients.

BACKGROUND: The presence of significant elevation of pulmonary vascular resistance is a major risk factor for death after orthotopic heart transplantation. The choice of procedure for the pediatric patient remains contentious. METHODS: We report three pediatric patients with pulmonary hypertension and raised pulmonary resistance, including two infants, in whom heterotopic transplantation was performed with smaller donor hearts. The hearts were anastomosed to provide left ventricular support alone because predominant left ventricular failure was present, the pulmonary resistance was expected to fall gradually after surgery, and we wished to avoid the potential problems of a pulmonary conduit associated with growth and possible reoperation. RESULTS: The clinical results have been satisfactory in all three patients, who were well and without symptoms. No pulmonary compromise was observed in the smaller thoracic cavity of the two infants. The transpulmonary gradient fell in all three patients, although this reduction was not immediate. CONCLUSIONS: This technique in carefully selected recipients can allow safer transplantation in pediatric patients with elevated pulmonary resistance, can increase the donor pool by allowing use of smaller hearts and nonideal donors, and may reduce the mortality on the transplant waiting list by providing earlier transplantation.

Cogan's syndrome with aortitis, aortic regurgitation, and aortic arch vessel stenoses.

Cogan's syndrome of interstitial keratitis and vestibuloauditory dysfunction is rare. Systemic vasculitic manifestations occur, and 10% of patients with this syndrome have aortic valvular disease. A patient with Cogan's syndrome is presented who had aortitis of the ascending thoracic aorta, severe aortic valve regurgitation, orificial stenosis of the right coronary artery, and orificial stenoses of all three aortic arch vessels. Histopathology confirmed aortitis. Aortic valve replacement combined with coronary and aortic arch vessel reconstruction was required for correction.

Can a dilated coronary sinus produce left ventricular inflow obstruction? An unrecognized entity.

Drainage of a persistent left superior vena cava to the coronary sinus is a common congenital lesion associated with dilatation of the coronary sinus. We report on 4 cases in which marked enlargement of the coronary sinus was present, immediately superior to and partially occluding the mitral valve, with consequent obstruction to left ventricular inflow. In 1 patient, presenting with cardiac failure in early infancy, this abnormality was the major defect, mimicking the features of cor triatriatum, and surgical correction led to significant symptomatic improvement. In 3 other patients this abnormality was associated with other congenital lesions, and it is postulated that in these cases impairment of flow into the left ventricle in the presence of an atrial septal defect elevated the left atrial pressure and increased the shunt across the atrial septum, thereby increasing the symptoms and clinical findings. Surgical reduction of the enlarged coronary sinus was performed in each case through the interatrial septum, and the technique is described.

Staged conversion to arterial switch for late failure of the systemic right ventricle.

Late failure of the systemic right ventricle is seen in up to 10% of patients after atrial switch for transposition of the great arteries and in patients with atrioventricular and ventriculoarterial discordance. Since 1981, 24 such patients have entered a program to achieve conversion to arterial switch. The primary diagnoses were transposition of the great arteries with ventricular septal defect (n = 10), transposition of the great arteries with intact ventricular septum (n = 5), Taussig-Bing anomaly (n = 4), and atrioventricular and ventriculoarterial discordance (n = 5). The mean interval from atrial switch to right ventricular failure was 7 years. Four patients underwent direct conversion to arterial switch, with one operative death. In 3 of these patients the initial left ventricular pressure was high. The fourth patient was too sick to undergo banding, and he required left ventricular assist device support after switch conversion. The other 20 patients underwent 34 procedures to place or tighten a pulmonary artery band to prepare the left ventricle to tolerate systemic pressure. There was one band-related operative death. Twelve patients have thus far gone on to switch conversion 13 days to 5 years (mean, 26 months) after banding. In total, therefore, 16 patients have had an arterial switch with atrial reconstruction. The early mortality for switch conversion was 2 of 16 (12.5%; 70% confidence limits, 4% and 27%), with one late death 12 months after operation. Including operative mortality, the 1-year actuarial survival probability after conversion was 80% (70% confidence limits, 62% and 92%). All survivors are asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital Heart Surgery Nomenclature and Database Project: corrected (discordant) transposition of the great arteries (and related malformations).

The extant nomenclature for congenitally corrected transposition of the great arteries is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Congenitally corrected transposition of the great arteries is a complex cardiac lesion that is associated with ventricular septal defect, left ventricular outflow tract obstruction, and tricuspid valve abnormalities. Nomenclature for this lesion has been variable and confusing. Herein we attempt to clarify the terminology, with an emphasis on identification of synonymous and nonsynonymous appellations. A comprehensive database set is presented that is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented that will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Incipient left ventricular rupture complicating anomalous left coronary artery.

A 4-month-old girl presented with 2 weeks of symptoms and physical signs of heart failure. Echocardiography demonstrated marked left ventricular dilation, thinning of the myocardium with anterolateral akinesis, mitral regurgitation, a moderate pericardial collection, and an anomalous left coronary artery from the pulmonary artery. At operation there was a tense hemopericardium and a site of imminent rupture through a transmural anterior infarction. The anomalous artery was reimplanted in the ascending aorta, and an extensive infarct resection and ventricular repair performed. Support with a left ventricular assist device was required for 3 days, but the infant subsequently made a satisfactory recovery. Left ventricular rupture is a very rare complication of this lesion, but should be considered if there is evidence of a pericardial collection.

Depressed function in remote myocardium after myocardial infarction: influence of orotic acid.

BACKGROUND: We have previously shown that infarction impairs recovery of global function after subsequent cardioplegic arrest and that therapy with orotic acid improves recovery. The aim of this study was to measure the effect of infarction on regional and global left ventricular function and to determine whether orotic acid exerts a beneficial effect exclusive of the effects of cardioplegia. METHODS: Acute myocardial infarction was produced in dogs. They then received either orotic acid or placebo (control) orally (n = 12 per group). Fractional radial shortening and systolic wall thickening were measured by two-dimensional echocardiography before and 1 and 3 days after infarction with and without beta-adrenergic blockade, and in 6 dogs up to 9 days after infarction. Global function was measured under anesthesia 4 days after infarction. RESULTS: In control animals, fractional radial shortening in the infarct decreased from 20.6% +/- 5.1% before infarction to 3.0% +/- 2.2% at day 1 and to 1.9% at day 3 (p < 0.01). In the border zone radial shortening declined from 21.9% +/- 3.7% to 11.0% +/- 2.3% at day 1 and 9.3% +/- 2.8% at day 3 (p < 0.05). In the noninfarcted myocardium radial shortening also declined from 27.1% +/- 1.9% before infarction to 18.3% +/- 2.3% on day 1 (p < 0.05) and to 16.0% +/- 2.8% on day 3 after infarction (p < 0.05) with recovery to preinfarct levels by 9 days after infarction. These findings were confirmed by measurements of systolic thickening. Before infarction beta-receptor blockade decreased fractional shortening in all regions of the left ventricle, but this effect was absent on day 3 after infarction, implying that the myocardium had become less responsive to beta-adrenergic stimulation. Measurements of global function 4 days after infarction showed marked depression of stroke work. There was no effect of orotic acid treatment on regional or global function. CONCLUSIONS: Myocardial infarction causes reversible depression of resting function and beta-adrenergic responsiveness in the remote and border zone areas, which is not prevented by metabolic therapy with orotic acid. This finding may explain the adverse response of the infarcted heart to cardioplegic arrest.

Senning plus arterial switch operation for discordant (congenitally corrected) transposition.

BACKGROUND: Congenitally corrected transposition of the great arteries is a complex cardiac lesion, usually associated with ventricular septal defect, left ventricular outflow tract obstruction, and tricuspid valve abnormalities. A subset of patients without left ventricular outflow tract obstruction have undergone Senning plus arterial switch operation in an attempt to place the left ventricle in the systemic circuit and the right ventricle in the pulmonary circuit. METHODS: Fourteen patients have had the operation performed since July 1989. Age and weight medians were 12 months (range, 0.5 to 120 months) and 8.2 kg (range, 3.2 to 34 kg). All but 1 patient had a left ventricular to right ventricular pressure ratio greater than 0.7, due to a large ventricular septal defect (with or without a previous pulmonary artery band), severe congestive heart failure caused by right ventricular dysfunction and tricuspid insufficiency, or a pulmonary artery band for left ventricular retraining. At least 10 patients had strong contraindications to "classic" repair, including right ventricular hypoplasia (n = 2), moderate to severe right ventricular dysfunction (n = 5), or moderate to severe tricuspid insufficiency (n = 9). RESULTS: There was one hospital death, occurring in a neonate (7%; 95% confidence interval = 0% to 34%). Actuarial survival beyond 10 months is 81% (95% confidence interval = 42% to 95%), currently with 389 patient-months of total follow-up time. The median grade of tricuspid insufficiency fell from 3/4 preoperatively to 1/4 postoperatively (p = 0.003). Right ventricular function is normal in 11/12 current survivors, all but 1 of whom are in New York Heart Association class I or II. CONCLUSIONS: Senning plus arterial switch operation is a good option for selected patients with congenitally corrected transposition of the great arteries with a similar or lower early risk (as compared with classic repairs). Some of the long-term problems associated with congenitally corrected transposition of the great arteries may be avoided with this strategy.

Does left ventricular outflow tract obstruction influence outcome of interrupted aortic arch repair?

BACKGROUND: In previous studies left ventricular outflow tract obstruction (LVOTO) has been recognized as an important factor affecting survival and reoperation probability in patients having repair of an interrupted aortic arch (IAA). METHODS: All 72 patients who underwent operation for IAA from January 1, 1985 to June 30, 1997 were reviewed. The presence or absence of LVOTO was noted and the immediate and long-term results were analyzed. RESULTS: Type A IAA was found in 23 patients and type B IAA in 49 patients. Anomalous right subclavian artery was noted in 15 patients, all of whom had type B IAA. LVOTO was identified in 36 patients before arch repair and was associated with the presence of type B IAA and anomalous right subclavian artery (p = 0.02 and 0.007, respectively). There were 2 hospital deaths (within 30 days) for a mortality of 2.8% (confidence limit [CL] = 0% to 6.6%). There were 7 late deaths over 3,737 patient-months of follow-up (9.7%, CL = 2.9% to 16.6%). Actuarial survival for the whole cohort was 84.8% (CL = 73.2% to 94.4%) at 12 years. There was 87% 10-year survival (CL = 60% to 93%) for patients with LVOTO at presentation compared with 83% (CL = 62% to 92%) for patients without LVOTO (p = 0.85, hazard function 0.87). Twenty-eight patients have required at least one reoperation. The use of conduits to restore right ventricular to pulmonary artery continuity predicted the need for reoperation (p = 0.0001). Patients with presence of a nonseptatable heart were also more likely to need reoperation (p = 0.027) when compared to the rest of the cohort. Freedom from reoperation was 47.3% (CL = 30% to 62%) at 12 years. In patients with LVOTO, freedom from reoperation (55% at 10 years, CL = 33% to 72%) was not significantly different from those patients without LVOTO at presentation (29% at 10 years, CL = 7% to 56%; p = 0.97, hazard function 0.7). Actuarial freedom from recurrent arch obstruction requiring reintervention was 82.7% (CL = 66.7% to 98.7%) at 12 years. CONCLUSIONS: Neonatal complete repair of patients with IAA is possible with low mortality. LVOTO was not a significant risk factor for hospital or late death in patients having complete repair of IAA during this period. The use of conduits for right ventricular to pulmonary artery continuity and the presence of a nonseptatable heart are important risk factors for further operation and will continue to provide added morbidity to these patients.

Damus-Kaye-Stansel connections in children with previously transected pulmonary arteries.

BACKGROUND: In patients with a univentricular arteriovenous connection, transection of the main pulmonary artery may be performed as part of a bidirectional cavopulmonary shunt or Fontan procedure. The proximal stump of the pulmonary artery may remain in the systemic circulation. In cases with a discordant ventriculoarterial connection, subsequent restriction of the bulboventricular foramen may lead to subaortic stenosis. The subaortic stenosis can be corrected in some patients by directing the systemic flow through a combined nonobstructed aortopulmonary outlet, as in the Damus-Kaye-Stansel connection. Previous closure of the pulmonary artery has been considered by some investigators to be a relative contraindication to the Damus-Kaye-Stansel procedure, unless an allograft root can be added to the circuit after excision of the closed pulmonary stump. METHODS: Three patients with previously transected pulmonary arteries underwent a modified Damus-Kaye-Stansel connection using the native pulmonary valve and the proximal pulmonary artery stump. RESULTS: The native pulmonary valves have functioned well despite thrombus formation in the proximal stump in 2 patients before Damus conversion. All 3 patients are alive and well after 108, 19, and 3 months, with competent nonobstructed ventriculoarterial connections. CONCLUSIONS: If transection and closure of the pulmonary artery as part of a previous palliation has spared the pulmonary valve, then the native pulmonary outlet might be used for a safe Damus-Kaye-Stansel connection.

Arterial switch in hearts with left ventricular outflow and pulmonary valve abnormalities.

BACKGROUND: Pulmonary valve and left ventricular outflow tract abnormalities (LVOT) may not be absolute contraindications to arterial switch operation (ASO). METHODS: In this study we analyze long-term outcome for 26 such transposition patients (6.3% of our ASO cohort). Median age and weight were 69 days (7 to 3,631 days) and 4.5 kg (2.6 to 34 kg). Pulmonary valve abnormalities included bicuspid valve (n = 4) and dysplastic valve (n = 5). The LVOT abnormalities (n = 17) included accessory atrioventricular valve/endocardial cushion tissue, fibromuscular ring, anomalous muscle bands, and septal malalignment. Patients with dynamic LVOT obstruction were excluded. The median preoperative left ventricular to pulmonary artery peak systolic pressure gradient was 30 mm (0 to 93 mm), or 50 mm (16 to 93 mm) if patients with isolated valve abnormalities are excluded. The ASO was performed according to our standard technique with or without LVOT resection or pulmonary valvotomy as required. RESULTS: There were two perioperative deaths (7.7%; 95% confidence interval, 0.9% to 25%), and no late deaths during 1,934 patient-months of follow-up time. Actuarial freedom from reoperation for neoaortic valve or LVOT problems is 87% (+/- 7) at 130 months, representing two reoperations. One was performed for neoaortic insufficiency plus LVOT obstruction, and the other for isolated LVOT obstruction. One patient currently has significant neoaortic insufficiency, and median gradient at last follow-up is 0 mm Hg (range, 0 to 35 mm Hg). CONCLUSIONS: The ASO can be performed in selected patients with transposition of the great arteries and with LVOT abnormalities with early and late survival and functional status similar to that of matched patients with normal pulmonary valves and LVOT (p > 0.05), but with a greater hazard for reoperation (p < 0.05). Selection for ASO should be based on anatomic criteria rather than left ventricular to pulmonary artery gradient alone, to avoid assigning these patients with transposition of the great arteries to treatment strategies less satisfactory than ASO.

Allograft aortic valve replacement: long-term follow-up.

Aortic valve replacement using an allograft aortic valve has been performed on 804 patients. From December 1969 to May 1975, 124 patients received a nonviable allograft valve sterilized by incubation with low-dose antibiotics and stored for weeks by refrigeration at 4 degrees C (series 1). From June 1975 to January 1994, 680 patients received viable allograft valves, now cryopreserved early within 2 hours of collection from transplant recipient donors, 6 hours for multiorgan donor valves and 23 hours (mean) for autopsy valves from donor death. The 30-day mortality was 8.9% +/- 5% (95% confidence limits) for series I and 2.8% +/- 1% (95% confidence limits) for series II. Actuarial patient survival including hospital mortality at 15 years was 56% +/- 5% for series I and 62% +/- 5% for series II. The probability of a thromboembolic event was low, freedom at 15 years being 95% +/- 1% for patients receiving allografts with or without associated coronary bypass procedures and 81% +/- 5% for patients having allografts with other associated procedures (eg, mitral valve operations). Actuarial freedom from endocarditis was similar for the two series, 91% +/- 3% (series I) and 94% +/- 2% (series II) at 15 years. The freedom from valve incompetence, from reoperation for all causes, and from structural deterioration demonstrated clearly the inferiority of the 4 degrees C stored allograft valves. For structural deterioration as identified clinically, at reoperation and at death, freedom from this event at 15 years was 45% +/- 6% for series I and 80% +/- 5% for series II (p value for the difference is 0).(ABSTRACT TRUNCATED AT 250 WORDS)

Root replacement for all allograft aortic valves: preferred technique or too radical?

From November 1985 to January 1994, 146 patients have received a viable cryopreserved allograft for aortic root replacement. The follow-up was complete, with all events included to March 1st, 1994. The median age of patients was 49 years; 83.6% were male. Valve dysfunction (91 patients), primary aortic wall disease (45 patients), and a combination of both (10 patients) were the indications for aortic root replacement. The current operative mortality is 1.7% (three deaths in 172 patients to July 1st, 1994). Four late deaths have occurred, with an 8-year actuarial survival of 85% +/- 8% (95% confidence limits). Endocarditis (two events) and thromboembolism (four events) had a low incidence. Structural deterioration (three events) and reoperation for all causes (nine events) have constituted low morbidity and are compared with the results after non-root allograft implantation techniques. The clinical and echocardiographic evidence indicates that the immediate results of valve function with root replacement are superior. But no statistical difference between aortic root replacement and non-root procedures is apparent at 8 years, indicating that a longer follow-up is required before the answer to the question "preferred technique or too radical" can be answered.