Kirsten Finucane

New White Matter Brain Injury After Infant Heart Surgery Is Associated With Diagnostic Group and the Use of Circulatory Arrest

Background— Abnormalities on magnetic resonance imaging scans are common both before and after surgery for congenital heart disease in early infancy. The aim of this study was to prospectively investigate the nature, timing, and consequences of brain injury on magnetic resonance imaging in a cohort of young infants undergoing surgery for congenital heart disease both with and without cardiopulmonary bypass. Methods and Results— A total of 153 infants undergoing surgery for congenital heart disease at <8 weeks of age underwent serial magnetic resonance imaging scans before and after surgery and at 3 months of age, as well as neurodevelopmental assessment at 2 years of age. White matter injury (WMI) was the commonest type of injury both before and after surgery. It occurred in 20% of infants before surgery and was associated with a less mature brain. New WMI after surgery was present in 44% of infants and at similar rates after surgery with or without cardiopulmonary bypass. The most important association was diagnostic group (P<0.001). In infants having arch reconstruction, the use and duration of circulatory arrest were significantly associated with new WMI. New WMI was also associated with the duration of cardiopulmonary bypass, postoperative lactate level, brain maturity, and WMI before surgery. Brain immaturity but not brain injury was associated with impaired neurodevelopment at 2 years of age. Conclusions— New WMI is common after surgery for congenital heart disease and occurs at the same rate in infants undergoing surgery with and without cardiopulmonary bypass. New WMI is associated with diagnostic group and, in infants undergoing arch surgery, the use of circulatory arrest.

Use of Monogen for pediatric postoperative chylothorax

BACKGROUND Postoperative chylothorax is a potentially serious complication of pediatric cardiac surgery. The purpose of this study was to report the use of Monogen enteral formula for the management of pediatric postoperative chylothorax. METHODS A retrospective, single-institution 2-year study of all patients with a diagnosis of postoperative chylothorax was conducted. Chylothorax was diagnosed in 25 patients after a total of 535 cardiac operations in children younger than 10 years, for an incidence of 4.7%. Eighteen patients had been given Monogen, an enteral low long-chain triglyceride formula, as initial treatment. Six had been given total parenteral nutrition. The following variables were related to outcome and response to Monogen: age, sex, weight, underlying condition, type of surgery, interval between surgery and chylothorax diagnosis, duration and daily volume of chyle leak, central venous pressure, residual lesions, and weight loss. RESULTS Enteral feeding with Monogen was successful for 14 of 18 patients with a response to treatment evident by the end of the third day. No variables predicted which patients would respond to Monogen. Body weight was maintained or increased in 14 of the 17 surviving patients taking Monogen. A return to normal diet at 4 +/- 1 weeks from the day of pleural drain removal did not result in recurrent chylothorax. CONCLUSIONS A trial of Monogen is recommended as initial treatment for postoperative chylothorax unless enteral feeding is contraindicated.

Timing of diagnosis affects mortality in critical congenital heart disease

Objective Screening for critical congenital heart disease (CHD) with prenatal ultrasound or postnatal pulse oximetry has the potential to improve outcome. To guide screening recommendations, this study aimed to identify the proportion and outcome of major CHD diagnosed before (early) or after (late) postnatal discharge prior to the introduction of postnatal oximetry screening. Design A retrospective, population-based review of all major CHD in New Zealand from 2006 to 2010. The timing of diagnosis relative to discharge and to intervention in critical and non-critical cases with intention to treat was determined, as was the relationship of diagnostic timing to mortality at 1 year of age. Results Late diagnosis occurred in 20% of critical and 51% of non-critical cases. Mortality occurred in 18% of critical vs 8% of non-critical cases. Mortality was lower with an early diagnosis of critical CHD (early diagnosis 16% vs late diagnosis 27%, p=0.04). Isolated critical CHD benefited most from early diagnosis (mortality, early diagnosis 12% vs late diagnosis 29%, p=0.002). Early diagnosis occurred in >90% critical complex CHD and hypoplastic left heart syndrome, 85% d-transposition of the great arteries (d-TGA) and 53% critical left ventricular outflow tract obstruction (LVOTO). Deaths in d-TGA and LVOTO primarily occurred prior to intervention and for d-TGA most often when birth was distant from the cardiac centre. Conclusions Excess mortality occurs following late diagnosis of critical CHD, and for d-TGA even with early diagnosis if intervention is not immediately available. Antenatal detection retains an important role in reducing mortality related to critical CHD.

Extracardiac conduit with a limited maze procedure for the failing Fontan with atrial tachycardias

BACKGROUND Atrial arrhythmias are a frequent late complication of Fontan procedures. Conversion to an extracardiac conduit combined with reducing right atrial size should improve hemodynamics and reduce the development of tachyarrhythmias. More effective control may be achieved by interrupting atrial arrhythmia circuits and atrial pacing. METHODS Between May 1997 and October 2001, 6 patients underwent a revision of their intracardiac Fontan anastomosis. The conversion included an extracardiac conduit insertion, limited right atrial maze procedure, and pacemaker placement. Ages ranged from 14 to 34 years (mean, 22.8 years) at an average of 14.6 +/- 4.4 years after their original Fontan procedure. All of the patients had medically uncontrollable atrial tachyarrhythmias with markedly reduced exercise tolerance. RESULTS All of the patients survived with an average hospital stay of 16.7 days. Exercise tolerance has improved in all 6 patients, and atrial tachycardias have either decreased (n = 2) or disappeared (n = 4). Two patients are taking antiarrhythmic medications other than digoxin. Follow-up is a mean of 28.5 months. CONCLUSIONS Limited right atrial maze procedure, atrial size reduction, and pacemaker implantations are worthwhile additions to simple conversion to an extracardiac conduit in the failing Fontan.

Ten-year outcomes of Fontan conversion in Australia and New Zealand demonstrate the superiority of a strategy of early conversion

OBJECTIVE To investigate the benefits of a strategy of early Fontan conversion. METHODS Using the Australia and New Zealand Fontan Registry, retrospective analysis of their long-term follow-up data was performed. RESULTS Between 1990 and 2014, a total of 39 patients underwent surgical conversion in 6 centres at a median age of 23.8 years (IQR: 19.3-28.2), 18.7 ± 5.0 years post-Fontan. One centre tended to perform conversion earlier: interval since first documented arrhythmia 2.9 ± 4.0 vs 4.0 ± 4.2 years, average NYHA Class 2 ± 0.4 vs 3 ± 0.9 (P = 0.008), mean number of preop anti-arrhythmics 1 ± 0.4 vs 2 ± 0.6 (P = 0.05). Two patients underwent conversion to an extracardiac conduit only, while 36 had concomitant right atrial cryoablation, of which 16 also had pacemaker implantation. Nine patients suffered major cardiac-related complications (7 low output syndrome, 3 ECMO, 3 acute renal failure, one stroke) (2/17 from the early conversion centre and 7/22 of the others; P = 0.14). Four patients died in hospital (10.3%) and 4 late after a median of 0.9 years [95% confidence interval (CI): 0.5-1] after conversion. An additional 2 patients needed transplantation at 1 and 8.8 years after conversion, respectively. The 10-year freedom from heart transplantation was 86% (95% CI: 51-97%). Outcomes from the centre with an early conversion strategy were significantly better: 8-year freedom from death or heart transplantation was 86% (95% CI: 53-96) vs 51% (95% CI: 22-74; log-rank P = 0.007). Eight additional patients required pacemaker implantation and 5 had arrhythmia recurrence. CONCLUSIONS Fontan conversion is associated with lasting survival outcomes up to 10 years after conversion. A strategy of surgical conversion at earlier stage of failure may be associated with better survival free from transplantation.

Amplitude-Integrated Electroencephalography and Brain Injury in Infants Undergoing Norwood-Type Operations

BACKGROUND Perioperative brain injury is common in infants undergoing cardiac surgery. Amplitude-integrated electroencephalography (aEEG) provides real-time neurologic monitoring and can identify seizures and abnormalities of background cerebral activity. We aimed to determine the incidence of perioperative electrical seizures, and to establish the background pattern of aEEG, in neonates undergoing Norwood-type palliations for complex congenital heart disease in relation to outcome at 2 years. METHODS Thirty-nine full-term neonates undergoing Norwood-type operations underwent aEEG monitoring before and during surgery and for 72 hours postoperatively. The perfusion strategy included full-flow moderately hypothermic cardiopulmonary bypass with antegrade cerebral perfusion. Amplitude-integrated electroencephalography tracings were reviewed for seizure activity and background pattern. Survivors underwent neurodevelopmental outcome assessment using the Bayley Scales of Infant Development (3rd edition) at 2 years of age. RESULTS Thirteen (33%) infants had electrical seizures, including 9 with intraoperative seizures and 7 with postoperative seizures. Seizures were associated with significantly increased mortality, but not with neurodevelopmental impairment in survivors. Delay in recovery of the aEEG background beyond 48 hours was also associated with increased mortality and worse motor development. CONCLUSIONS Perioperative seizures were common in this cohort. Intraoperative seizures predominantly affected the left hemisphere during antegrade cerebral perfusion. Delayed recovery in aEEG background was associated with increased risk of early mortality and worse motor development. Ongoing monitoring is essential to determine the longer-term significance of these findings.

Arterial Switch Operation: Early and Late Outcome for Intramural Coronary Arteries

BACKGROUND Intramural coronary artery course (IMCA) is associated with an increased risk of coronary event and mortality after the arterial switch operation (ASO). We describe early and late outcomes at our institution from 1996 to 2006. METHODS Operation notes for all patients who underwent ASO within 60 days of birth were reviewed, and those with IMCA were identified. Mortality and morbidity were obtained from discharge summary, predischarge electrocardiogram, and echocardiogram. Follow-up included clinical review, electrocardiogram, echocardiography, dobutamine stress echocardiography, and angiography. RESULTS Eighteen patients of 215 in the cohort (8.4%) had IMCA. Intramural coronary artery course was more common in patients from French Polynesia (6 of 17; 35.3% versus 12 of 198; 6.1%; p=0.001). Early mortality for patients with IMCA was 1 of 18 (5.6%) compared with 6 of 197 (3%) for those without IMCA (p=0.46). One IMCA patient was lost to follow-up. The remaining 16 are alive and asymptomatic. Of the 13 who underwent angiography, 2 had minor coronary artery stenoses at initial nonselective aortic root angiography. Both stenoses resolved at subsequent selective coronary angiography. None of the 11 who underwent dobutamine stress echocardiography had inducible ischemia. CONCLUSIONS We report a high prevalence of IMCA in an ASO population, particularly among patients referred from French Polynesia. Intramural coronary artery course was not a risk factor for mortality after ASO. Angiography demonstrated excellent short-term and long-term structural outcome for IMCA.

Improved Long-Term Survival for Rheumatic Mitral Valve Repair Compared to Replacement in the Young

Background: Mitral valve (MV) repair offers potential advantages over replacement in patients with rheumatic heart disease (RHD). We present the first long-term study that compares MV repair with replacement in children with RHD. Methods and Results: Single institute retrospective review of patients with RHD under 20 years of age, who underwent their first isolated MV surgery between 1990 and 2006. Of the 81 patients, 98% were Māori or Pacific Islander. The median age was 12.7 (3-19) years. The MV was repaired in 59%, a mechanical valve replacement (MVR) took place in 35% and bioprosthetic valve replacement in 6% of the patients. Follow-up data were available for 91.4% of the patients with mean follow-up of 7.6 years (range 0-19.4 years), a total of 620 patient years. Actuarial survival at 10 and 14 years for patients with MVR was 79% and 44%, compared to 90% and 90% for patients who underwent repair (P = .06). Actuarial freedom from late reoperation at 10 and 14 years for patients with MVR was 88% and 73%, compared to 76% and 76% for patients with repair (P = .52). Actuarial freedom from thrombotic, embolic, and hemorrhagic events at 10 and 14 years for patients with MVR was 63% and 45%, compared to 100% and 100% for patients with repair P < .01). Conclusion: This study shows that MV repair is superior to replacement for RHD in the young with follow-up to 19 years. Repair offers a survival advantage, greater freedom from valve-related morbidity, and long-term durability that equals that of MVR.

Fulminant mitral regurgitation due to ruptured chordae tendinae in acute rheumatic fever

Aims:  Description of the presentation and management of cases of fulminant mitral regurgitation in acute rheumatic fever (ARF).

Perioperative risk factors for impaired neurodevelopment after cardiac surgery in early infancy

Objective Historical cohort studies have reported adverse neurodevelopment following cardiac surgery during early infancy. Advances in surgical techniques and perioperative care have coincided with updating of neurodevelopmental assessment tools. We aimed to determine perioperative risk factors for impaired neurodevelopment at 2 years following surgery for congenital heart disease (CHD) in early infancy. Design and patients We undertook a prospective longitudinal study of 153 full-term infants undergoing surgery for CHD before 2 months of age. Infants were excluded if they had a genetic syndrome associated with neurodevelopmental impairment. Outcome measures Predefined perioperative parameters were recorded and infants were classified according to cardiac anatomy. At 2 years, survivors were assessed using the Bayley Scales of Infant Development-III. Results At 2 years, 130 children (98% of survivors) were assessed. Mean cognitive, language and motor scores were 93.4±13.6, 93.6±16.1 and 96.8±12.5 respectively (100±15 norm). Twenty (13%) died and 12 (9%) survivors had severe impairment (score <70), mostly language (8%). The lowest scores were in infants born with single ventricle physiology with obstruction to the pulmonary circulation who required a neonatal systemic-to-pulmonary artery shunt. Additional risk factors for impairment included reduced gestational age, postoperative elevation of lactate or S100B and repeat cardiac surgery. Conclusions In the modern era of infant cardiac surgery and perioperative care, children continue to demonstrate neurodevelopmental delays. The use of updated assessment tools has revealed early language dysfunction and relative sparing of motor function. Ongoing follow-up is critical in this high-risk population.