Surgical Management of Ebstein Anomaly: The Australia and New Zealand Experience.

BACKGROUND: Ebstein anomaly is a rare congenital anomaly of the tricuspid valve which presents challenges to cardiac surgeons due to the spectrum of the disease and the technical difficulty of valve repair. The natural history of the anomaly differs between patients presenting in the neonatal period to those presenting in adulthood. METHODS: A retrospective review of all patients >15 years of age with Ebstein anomaly, undergoing surgery on the tricuspid valve at 6 centers across Australia and New Zealand was performed. Patients from 1985 to 2019 were included in the study. RESULTS: A total of 125 patients were included in the study, 76 patients (60%) undergoing tricuspid valve repair, of which 23 patients underwent a Cone repair and 49 (40%) had a tricuspid valve replacement. The mean follow-up was 7.9 ± 7.3 years. Postoperatively, early mortality was 3 patients (2%) and 10-year survival was 91.5%. A postoperative pacemaker was required in 24 patients (19%). Reoperation was required in 21 patients (17%). There was no statistically significant difference in survival or reoperation between patients who underwent repair or replacement of the tricuspid valve; however, with a small number of patients in long-term follow-up. CONCLUSION: Older children and adult patients undergoing surgery for Ebstein anomaly in Australia and New Zealand experience good medium-term postoperative survival. Repair of the valve is achieved in a significant proportion of patients with increasing use and success with the Cone repair technique.

Enteral feeding in duct-dependent congenital heart disease.

BACKGROUND: Infants with duct-dependent congenital heart lesions are treated with a prostaglandin E1 infusion. We aimed to describe the feeding strategies used at our institution in such infants, and to describe the incidence of necrotising enterocolitis (NEC) in this patient group, investigating whether enteral feeding is associated with a higher risk. METHODS: Patients diagnosed with hypoplastic left heart syndrome, coarctation of the aorta, pulmonary atresia, or transposition of the great arteries born over a defined period were identified. Premature infants, those with pre-existing gastrointestinal disease, and those who never received prostaglandin were excluded. Data were compared using univariable and multivariable logistic regression models. RESULTS: A total of 177 patients were identified, of them 18 received a diagnosis of suspected or confirmed NEC. There was no association between the diagnosis of NEC and enteral feeding (P = 0.9). CONCLUSIONS: Based on these data, there does not appear to be an association between enteral feeding and NEC in infants receiving prostaglandin.

Extracorporeal membrane modality conversions.

We report the case of a patient with cardiovascular and respiratory failure due to severe anaphylaxis requiring multiple extracorporeal membrane oxygenation (ECMO) cannulation strategies to provide adequate oxygen delivery and ventilatory support during a period of rapid physiological change. ECMO provides partial or complete support of oxygenation-ventilation and circulation. The choice of which ECMO modality to use is governed by anatomical (vessel size, cardiovascular anatomy and previous surgeries) and physiological (respiratory and/or cardiac failure) factors. The urgency with which ECMO needs to be implemented (emergency cardiopulmonary resuscitation (eCPR), urgent, elective) and the institutional experience will also influence the type of ECMO provided. Here we describe a 12-year-old schoolgirl who, having been resuscitated with peripheral veno-venous (VV) ECMO for severe hypoxemia due to status asthmaticus in the setting of acute anaphylaxis, required escalation to peripheral veno-arterial (VA) ECMO for precipitous cardiovascular deterioration. Insufficient oxygen delivery for adequate cellular metabolic function and possible cerebral hypoxia due to significant differential hypoxia necessitated ECMO modification. After six days of central (transthoracic) VA ECMO support and 21 days of intensive care unit (ICU) care, she made a complete recovery with no neurological sequelae. The use of ECMO support warrants careful consideration of the interplay of a patient's pathophysiology and extracorporeal circuit dynamics. Particular emphasis should be placed on the potential for mismatch between cardiovascular and respiratory support as well as the need to meet metabolic demands through adequate cerebral, coronary and systemic oxygenation. Cannulation strategies occasionally require alteration to meet and anticipate the patient's evolving needs.

Paediatric heart transplantation in Australia comes of age: 21 years of experience in a national centre.

BACKGROUND: Heart transplantation (HT) is established therapy for end-stage heart failure in children with cardiomyopathy or congenital heart disease. AIMS: This review summarises experience at a national referral centre since the first local transplant. METHODS: Medical records of children referred for HT between 1 April 1988 and 1 January 2010 were retrospectively reviewed. All patients listed for HT were included. Survival analysis was used to summarise wait-list time to death/transplant, and separately, time to death in HT patients. RESULTS: One hundred and thirty-nine children were accepted on to the HT waiting list during the study (median age 7.7 (interquartile range (IQR) 2.5, 13.6) years), of whom 93 underwent HT (median age 10.9 (IQR 4.4, 14.6) years). Wait-list mortality was 32% (45 of 139 patients), lowest among children aged >10 years at listing (P < 0.001). Median time to HT was 69 days (range 29-146). Survival post-transplantation was 90% (95% confidence interval 82-95) at 1 year, 82% (72-89%) at 5 years and 68% (50-80%) at 10 years. Increasing case complexity over the study period included pre- and post-transplant circulatory support, management of pulmonary hypertension and introduction of ABO-incompatible HT for infants. Post-transplant survival did not vary according to age, pre-transplant diagnosis or use of pre-transplant circulatory support (all P > 0.05). CONCLUSIONS: Results of paediatric HT in Australia are comparable with international results, despite limitations of geographic isolation, small population and low organ donation rate. Increasing case complexity has not impacted on post-transplant survival.

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.

[Modified technique creating fenestration in the extracardiac Fontan completion; kissing anastomosis].

Acute or subacute occlusion of a fenestration between the Fontan chamber and the atrium causes low cardiac output status, sustained pleural effusion, and protein losing enteropathy in critical cases. To achieve reliable and long patency of the fenestration in extracardiac Fontan operations, we modified our technique for creating a fenestration, namely "kissing" anastomosis, in which the atrial incision is directly sutured to the surface of the extracardiac conduit leaving a few millimeters outside from the edge of the punched-out hole (fenestration). We applied this modification in 2 cases. The diameter of the hole is 4 mm (case 1) and 3 mm (case 2). The patients were anticoagulated by warfarin potassium after the surgery. The fenestrations were patent at 3- (case 1) and 1-month (case 2) after the surgery. Peripheral oxygen saturations at discharge were 86 (case 1) and 88% (case 2). There was no death or major complication. The described procedure is an effective alternative to maintain patency and function of the fenestration in extracardiac Fontan operations.

Pump-induced haemolysis: a comparison of short-term ventricular assist devices.

Centrifugal pumps are superior to roller pumps for extended support durations in terms of pump-induced haemolysis. In this study, we evaluated the commonly used Biomedicus BP 50 and compared it with the Jostra Rotaflow and a standard roller pump in an in vitro test circuit. Each circuit was run for a six-day period and repeated five times. Plasma haemoglobin values showed the roller pump to become more haemolytic than the Biomedicus (p = 0.022) and the Rotaflow. A statistically significant difference between the Biomedicus and the Rotaflow was observed on day six of the trial (p = 0.016), with the Rotaflow showing lower levels of haemolysis than the Biomedicus. These results support the use of the new generation centrifugal pump, the Rotaflow, as a suitable device for short-term ventricular assist.

Experience with the Jostra Rotaflow and QuadroxD oxygenator for ECMO.

Since April 1988, we have been able to offer extracorporeal membrane oxygenation (ECMO) to patients who are either failing ventilation or who need cardiopulmonary support following cardiac surgery. During this time, we have supported 211 patients, the majority of whom have been supported with the Avecor (Affinity, Avecor Cardiovascular Inc., Minneapolis, MN, USA) spiral wound silicone-membrane oxygenator. Microporous hollow-fibre oxygenators have been used (18%) at our center. However, due to their early failure, they have necessitated conversion to a device that potentially would last for the entire ECMO course, i.e., Avecor and, subsequently, have not been used routinely until the introduction of the QuadroxD (Jostra Medizintechnik AG, Hirrlingen, Germany). The recent development of the poly-4-methyl-1-pentene diffusion membrane allows us to utilize hollow-fibre technology with a true (nonmicroporous) membrane. This has enabled us to use this low-resistance device with all its inherent advantages, without plasma leakage necessitating circuit changeover. From July 2000, we have used the QuadroxD oxygenator for our patients requiring ECMO support. This has been in patients with weights ranging from 2.16-51.0 kg (n = 23), with the longest support being for 1119 hours. This new technology has enabled us to utilize a single device for all patient sizes, so we now have an ECMO circuit set up at all times, minimizing the time required for support to be available, potentially improving survivor morbidity.

Improved early ventricular performance with a right ventricle to pulmonary artery conduit in stage 1 palliation for hypoplastic left heart syndrome: evidence from strain Doppler echocardiography.

OBJECTIVE: To quantify non-invasively right ventricular (RV) performance in infants after stage 1 palliation for hypoplastic left heart syndrome (HLHS). DESIGN: Prospective, observational study with two dimensional and strain Doppler echocardiography. SETTING: Single tertiary paediatric cardiology centre. PATIENTS: Convenience sample of nine consecutive infants with HLHS. Four whose surgery involved a systemic to pulmonary artery (S-PA) shunt were compared with five whose surgery incorporated a right ventricle to pulmonary artery (RV-PA) conduit. METHODS: Basal RV free wall longitudinal strain rate, systolic strain (epsilon), and RV percentage area change were calculated during a single assessment between 27-50 days after surgery. RESULTS: Cardiopulmonary bypass time was longer in patients who underwent RV-PA (226 (30) minutes v 181 (18) minutes, p = 0.03), but cross clamp time, duration of ventilation, and inotrope use did not differ. Two patients in the S-PA group died, on days 29 and 60 after surgery. Peak systolic strain rate (-1.24 (0.19)/s v -0.91 (0.21)/s, p = 0.048), peak epsilon (-17.8 (1.8)% v -13.4 (2.0)%, p = 0.01), and RV percentage area change (56 (6)% v 25 (6)%, p < 0.01) were all greater among RV-PA patients. These indices also tended to be greater in survivors as a group. Ventricular loading conditions (oxygen saturations, diuretic treatment, and blood pressure) were similar in both groups. CONCLUSION: Strain Doppler echocardiography shows improved RV longitudinal systolic contractility in patients during convalescence after the RV-PA modification of stage 1 palliation for HLHS compared with those with an S-PA shunt.

Clinical features and management of isolated cleft mitral valve in childhood.

OBJECTIVES: We reviewed an institutional experience of isolated cleft mitral valve (ICMV), its clinical features, and management in a pediatric population. BACKGROUND: As ICMV is relatively uncommon, earlier reports highlighted its anatomical and echocardiographic features. Few studies have collated their clinical features with their outcome. METHODS: All patients with ICMV were retrospectively reviewed. Patients who were considered to have an atrioventricular septal defect or variant were excluded. RESULTS: Twenty patients (9 male, 11 female) were diagnosed with ICMV. Seven patients had associated cardiac lesions. The median age of diagnosis was 5.2 years (range 0.4 to 13.6 years). Echocardiography aided by color Doppler demonstrated the ICMV in all patients. However, an incomplete diagnosis was made in 4 of 20 patients before surgery. The severity of the mitral regurgitation (MR) at presentation was mild in 11, moderate in 8, and severe in 1 patient. In the 13 patients without associated cardiac lesions, 5 underwent mitral valve (MV) repair at median age of 5.2 years (range 1.2 to 7.7 years) for moderate to severe MR, 4 being symptomatic. The severity of the MR in seven of the eight unoperated patients has remained unchanged over the follow-up period (median 8.3 years, range 0.7 to 14.4 years). In total, 10 patients underwent MV repair (median 6.4, range 0.4 to 13.8 years). No patient required MV replacement. None of the 10 patients had more than mild MR over the follow-up period (median 0.6, range 0.2 to 11.0 years). CONCLUSIONS: Now readily diagnosable by echocardiography, ICMV is a correctable cause of MR with a good outcome. Surgery is indicated in those patients with moderate to severe MR and probably should be done early following diagnosis.

Model of complete separation of the hepatic veins from the systemic venous system.

BACKGROUND: In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors. METHODS: Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit. RESULTS: Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg. CONCLUSIONS: The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as the inferior vena cava pressure stays at the levels observed in Fontan circulation.

IL-6 and IL-8 levels after cardiopulmonary bypass are not affected by surface coating.

UNLABELLED: BACKGROUND.:Contact of blood with the surfaces of the cardiopulmonary bypass (CPB) circuit has been implicated as a cause of the inflammatory response. We undertook a prospective randomized trial of 200 pediatric patients, all with a calculated total bypass flow of less than 2.3 L/min (< 0.96 L/m2/min). METHODS: Patients were randomly assigned to 1 of 4 CPB groups: (1) Nonheparin-bonded circuit with no albumin preprime; (2) Nonheparin-bonded circuit with albumin preprime; (3) Heparin-bonded circuit with no albumin preprime; (4) Heparin-bonded circuit with albumin preprime. Measurements of cytokines, (interleukin [IL]-6, IL-8) and blood cell counts were made prebypass and 6 and 24 hours after institution of cardiopulmonary bypass. RESULTS: Analysis of variance showed no significant difference in any of the clinical or biochemical characteristics of the 4 groups. The interaction between heparin-bonded oxygenators and albumin preprime was not significant. No important differences in IL-6 or IL-8 concentrations were noted after CPB using either heparin or nonheparin-bonded oxygenators with albumin or albumin free preprime using two-way analysis of variance. CONCLUSIONS: Albumin preprime and heparin-bonding do not attenuate the inflammatory response component attributable to the concentration of these markers.

Advances in pediatric cardiac surgery.

During the past year there have been many important scientific and clinical publications addressing important aspects of pediatric cardiac surgery. Herein we review some of the more significant contributions, with our own commentary added. Space limitations prevent a more comprehensive review.

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.

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.

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.

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.

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.

Centrifugal ventricular assist in children under 6 kg.

OBJECTIVE: The clinical application of centrifugal ventricular assist devices (VAD) has generally been limited to adults and large paediatric patients. In our experience neonates and small paediatric patients requiring ventricular support post-cardiopulmonary bypass are well supported by VAD. In this study we analyse our experience. METHODS: We have examined the records of our VAD patients who weighed less than 6 kg. Thirty-four patients, ranging in age from 2 to 258 days (median 60 days) and weight from 1.9 to 5.98 kg (median 3.7 kg), underwent 35 VAD procedures. One patient was supported on VAD twice. RESULTS: All patients had congenital heart lesions and were placed on VAD either because they could not be weaned from cardiopulmonary bypass after repair or palliation of the lesion (71.5%), or for support in the post-operative period due to refractory low cardiac output (28.5%). Twenty-two of the 35 VAD procedures (0.63, 95% CI: 0.45-0.78) resulted in successful weaning and decannulation, this was similar to the weaning probability for patients greater than 6 kg (P = 0.07). There were 10 late deaths in this group, with a 1-year KM survival of 0.31 (95% CI: 0.17-0.47). Most late deaths were related to irreversible cardiac disease processes as were the elective discontinuance of VAD outcomes. Neither weight, age, VAD duration, CPB duration, X clamp duration, univentricular anatomy or TGA anatomy predicted successful discharge from hospital (P > 0.05)--Weight P = 0.576; Age P = 0.532; VAD duration P = 0.181; CBP duration P = 0.549; X clamp duration P = 0.984; Univentricular anatomy P = 0.481; TGA anatomy P = 0.099. CONCLUSION: We believe centrifugal ventricular assist is a realistic option in very small patients who require post-cardiopulmonary bypass support. It is relatively easy to establish and manage, the results, although showing no factors predictive of successful discharge, are encouraging.