Long-Term Outcomes of Mechanical Aortic Valve Replacement in Children.

When the options of aortic valve repair or the Ross procedure are not feasible or have been exhausted, mechanical aortic valve replacement (AVR) may provide a reliable and structurally durable alternative, but with the limitations of long-term anticoagulation, thrombosis risk and lack of valve growth potential. In this article, we review the longitudinal outcomes of mechanical AVR in children in our institution and compare them to those recently reported by others. From 1978 to 2020, 62 patients underwent mechanical AVR at a median age of 12.4 years (interquartile range (IQR): 8.6-16.8 years). The most common underlying diagnoses were: conotruncal anomalies (40%, 25/62), congenital aortic stenosis (16%, 10/62), rheumatic valve disease (16%, 10/62), connective tissue disease (8.1%, 5/62) and infective endocarditis (6.5%, 4/62). Thirty-two patients (52%, 32/62) had at least 1 prior aortic valve surgery prior to mechanical AVR. Early death was 3.2% (2/62). Median follow-up was 14.4 years (IQR: 8.4-28.2 years). Kaplan-Meier survival was 96.8%, 91.9%, 86.3%, and 81.9% at 1, 5, 10, and 20 years. On competing risk analysis, the proportion of patients alive without aortic valve reoperation at 1, 5, 10, and 20 years was 95.2%, 87.0%, 75.5% and 55.4%, respectively, while the proportion of patients that had aortic valve reoperation (with death as a competing event) at 1, 5, 10, and 20 years was 1.6%, 4.9%, 12.8%, and 28.5%, respectively. In conclusion, when the options of aortic valve repair or the Ross procedure are not feasible in children, mechanical AVR is an alternative, yet the long-term rates of mortality and need for aortic valve reoperation are of concern.

Clinical assessment can be lifesaving: Salvage of catastrophic cerebral ischemia by conversion to central extracorporeal membrane oxygenation.

Peripheral veno-artertial extracorporeal membrane oxygenation (VA-ECMO) is commonly used in the paediatric population for intractable respiratory and cardiac failure. One of the devastating complications of VA-ECMO is severe brain damage due to ischemia or haemorrhage. We describe a case of peripheral cervical VA-ECMO complicated by evolving right cerebral ischemia which was rescued with rapid conversion from peripheral to central VA-ECMO support. Notably, the patient had a complete circle of Willis. Following conversion, we observed complete resolution of neurological symptoms with full functional recovery.

Exercise Capacity and Reoperation Late After Transatrial Fallot Repair.

BACKGROUND: The exercise capacity long after repair of tetralogy of Fallot, when performed exclusively with a transatrial repair, is unclear. It is also unknown whether echocardiography and cardiopulmonary exercise testing can predict the risk of reoperation in this patient group. METHOD: We retrospectively reviewed the clinical records of 59 patients who underwent cardiopulmonary exercise testing after transatrial Fallot repair at a single centre. Patients underwent cardiopulmonary exercise testing at a mean age of 16.6±4.4 years, and at 15.3±4.1 years after Fallot repair. RESULTS: At testing, the volume of oxygen consumption at maximal exercise (VO2 max) was 71%±13% and the oxygen pulse was 80%±17% of predicted values. Seventeen (17) patients (29%) had a VO2 max superior to 80% of the predicted value. Thirty-two (32) patients (56%) had severe pulmonary regurgitation, three (5%) had moderate pulmonary regurgitation, and 12 (21%) had mild pulmonary regurgitation. After a mean of 7.8±3.9 years following cardiopulmonary exercise testing (23±5.3 years after the repair), 21 (40%) patients underwent reoperation. Right ventricular dilation and systolic function on echocardiography were both significantly associated with subsequent reoperation rates. Patients who had severe right ventricular dilation were eight times more likely to undergo subsequent reoperation (hazard ratio 8.67; 1.82-41.3; p=0.007). No cardiopulmonary exercise testing variable independently predicted reoperation. CONCLUSIONS: The exercise capacity at adolescence following transatrial repair of tetralogy of Fallot is maintained at around 70% of predicted values. Only the patients with normal right ventricular size and normal right ventricular function seemed to be protected from reoperation over the subsequent decade. We found no exercise variables which predicted reoperation.

Heart Transplantation after Univentricular Palliation: Improved Outcomes and Increased Complexity.

AIM: Heart transplantation (HT) in patients with failing univentricular circulation is often challenging. This is compounded by the ever-increasing number of patients with prior Norwood-type reconstruction of the aorta, large aortic root, and often dense adhesions from multiple prior operations. We aimed to elucidate differences in outcomes of HT in patients with prior univentricular palliations, with and without prior Norwood-type aortic arch reconstruction (ArchRec). METHODS: All patients who underwent HT for failed univentricular palliation during the 1990-2022 period were included in the study. RESULTS: Of 45 patients, 18 had undergone ArchRec. Hospital mortality improved in the recent era (17.4% before 2006 vs 0% after 2006; p=0.11), despite a higher proportion of patients with ArchRec (17.4% before 2006 vs 60.8% after 2006, p=0.002). Patients with ArchRec had a higher number of prior cardiac surgeries (4.1±1.5 vs 3.2±1.3, p=0.04), longer cardiopulmonary bypass time (320±23 vs 242±21 min, p=0.02), more concomitant arch reconstruction (33.3% vs 0%, p=0.02), greater need for post-HT extracorporeal membrane oxygenation (33.3% vs 3.7%; p=0.01) and longer hospital stay (37.1±30.5 days vs 23.6±11.8 days, p=0.04). Freedom from death or retransplantation for all patients was 91%, 73%, 67%, and 53% at 1, 5, 10, and 15-years, respectively. Prior ArchRec, Fontan procedure, and earlier eras were not risk factors for death. CONCLUSIONS: The outcomes of HT after univentricular palliation have improved in recent times and low operative mortality can be achieved. Despite increased complexity, good similar outcomes can be achieved in patients with and without prior arch reconstruction regardless of the palliation stage.

Congenital Aortic Valve Repair When the Options aren't Good: Truncus Arteriosus and Transposition of the Great Arteries.

Patients with truncus arteriosus and transposition of great arteries are prone to neo-aortic valve insufficiency. Although presenting at opposite ends of the age spectrum, both conditions tend to be commonly associated with neo aortic root dilatation. In patients with truncus arteriosus there is an additional complexity of quadricuspid valve morphology, which make up the majority of valves requiring repair. A unified approach to all these patients would include reduction and stabilization of the annulus and sinotubular junction, as well as achieving equal and symmetrical coaptation of the valve leaflets. By systematically employing these techniques, valve replacement should be avoidable in most children.

Acute rheumatic fever and rheumatic heart disease in children and adolescents in Victoria, Australia.

AIM: To describe the epidemiology and clinical profile of children and adolescents with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in Victoria, Australia. METHODS: A retrospective audit was undertaken of children and adolescents with ARF and RHD attending the Royal Children's and Monash Children's Hospitals in Victoria, Australia between 2010 and 2019. Potential cases were identified by searching multiple sources for relevant ICD-10-AM codes and keywords, then reviewed manually. For confirmed cases, we collected data on patient demographics, clinical features, comorbidities and management. RESULTS: Of 179 participants included, there were 108 Victorian residents and 71 non-Victorian residents. 126 had at least one episode of ARF during the study period and 128 were diagnosed with RHD. In the Victorian resident group, the overall incidence of ARF was 0.8 per 100 000 5-14 year olds. This incidence was higher in Victorian Aboriginal and/or Torres Strait Islander (3.8 per 100 000) and Pacific Islander (32.1 per 100 000) sub-populations. Of 83 Victorian residents who had an ARF episode, 11 (13%) had a recurrence. Most Victorian residents with RHD had mixed aortic and mitral valve pathology (69.4%) and moderate to severe disease (61.9%). Most non-Victorian residents were Aboriginal and/or Torres Strait Islander people (80.3%) and were commonly transferred for tertiary or surgical management of RHD (83.1%). CONCLUSIONS: ARF and RHD continue to affect the health of significant numbers of children and adolescents living in Victoria, including severe and recurrent disease. Specialised services and a register-based control program may help to prevent complications and premature death.

The Ross Procedure in Children: Defining the Optimal Age.

BACKGROUND: It has been proposed that delaying the Ross procedure to later in childhood, allowing autograft stabilisation and placement of a larger pulmonary conduit, may improve outcomes. However, the effect of age at the time of Ross procedure on outcomes remains unclear. METHODS: All patients who underwent the Ross procedure between 1995 and 2018 were included in the study. Patients were divided into four groups: infants, age 1 to 5 years, age 5 to 10 years and age 10 to 18 years. RESULTS: A total of 140 patients underwent the Ross procedure in the study period. Early mortality was 23.3% (7/30) for infants compared to 0% for older children (p<0.001). Survival at 15 years was significantly lower in infants (76.3%±9.9%), compared to children aged 1 to 5 years (90.9%±20.1%), 5 to 10 years (94%±13.3%), and 10 to 18 years (86.7%±10.0%), p=0.01. Freedom from autograft reoperation at 15 years was significantly lower in infants (58.4%±16.2%), compared to children aged 1 to 5 years (77.1%±14.9%), 5 to 10 years (84.2%±6.0%) and 10 to 18 years (87.8%±9.0%), p=0.01. Overall freedom from reoperation at 15 years was 13.0%±6.0% for infants, 24.2%±9.0% for children aged 1 to 5 years, 46.7%±15.8% for children aged 5 to 10 years, and 78.4%±10.4%, p<0.001. CONCLUSIONS: The Ross procedure performed after 10 years of age appears to be associated with improved freedom from reoperation, primarily due to a reduction in reoperation on the pulmonary conduit.

Poorer Self-Reported Physical Health and Higher Anxiety Trait in Young Adults With Previous Coarctation Repair.

BACKGROUND: Little is known about the impact of a coarctation repair on the functional outcomes of young adults. This study aimed to determine (1) the functional and mental health status in young adults with previous coarctation repair, and (2) the impact of late hypertension on their quality of life. METHODS: A cross-sectional study using validated self-reported questionnaires (Short Form 36 version 2 [SF-36v2], Beck Depression Inventory [BDI], and State-Trait Anxiety Inventory [STAI]) was performed in 54 patients aged 15-47 years with previous paediatric coarctation repair. Questionnaire scores were compared to healthy age- and gender-matched controls. Patients' previously published 24-hour blood pressure monitoring results were included. RESULTS: Late hypertension was present in 64% (34/54) at a mean of 29±8 years after coarctation repair. SF-36v2 mean physical component summary score was significantly lower in coarctation patients compared with controls (53.1±6.8 vs 56.0±4.7, p=0.02), but there was no significant difference in mean mental component summary score (p=0.2). SF-36v2 mean role emotional score tended to be associated with 10 mmHg increases in mean 24-hour systolic blood pressure (regression coefficient 4.3 p=0.06). STAI mean trait anxiety score tended to be higher in coarctation patients compared with controls (36.6±9.0 vs 33.5±7.8, p=0.06). There was no significant difference in BDI scores between patients and controls. CONCLUSIONS: Young adults with previous coarctation repair report poorer physical health and tended towards higher anxiety trait compared to healthy controls. Strategies to improve self-reported physical health and anxiety should be explored. Long-term assessment of quality of life outcomes in coarctation patients is warranted.

Replacement of the Mitral Valve Under One Year of Age: Size Matters.

Surgical management of mitral valve disease in neonates and infants is challenging. When repair is no longer feasible, replacement may become inevitable, but should only be considered as an option of last resort due to the remarkably high rate of associated morbidity and mortality. Mechanical valves are the preferred choice in large annuli, while stented conduits seem promising in smaller ones. In patients with a preoperative mitral valve annulus equal or larger than 15-16 mm, an intra-annular placement of the smallest mechanical valve available should be attempted. In patients with smaller annuli, the placement of a stented valved conduit seems to display a lower mortality risk. Supra-annular implantation of prostheses should be reserved for exceptional cases and to those familiar with this technique because of the high rate of associated complications.

Berlin Heart EXCOR Support in the First Year of Life: A Single Centre Experience.

BACKGROUND: Berlin Heart EXCOR Pediatric Ventricular Assist Device (BHE) (Berlin Heart AG, Berlin, Germany, BHE) is used worldwide for mechanical circulatory support as a bridge to transplantation or recovery for children with end-stage heart failure. The study aim was to evaluate morbidity and mortality of children less than one year old supported with BHE to identify predictors of adverse outcomes. METHODS: Data of all children aged less than one year supported with BHE between 2005 and 2018 at the Royal Children's Hospital, Melbourne were reviewed. Adverse events were defined using PediMACS criteria. RESULTS: Fourteen (14) children under 1 year of age were implanted with BHE at a median age and weight of 0.37 years (IQR 0.09-0.7) and 5.7 kg (IQR 3.5-7.95) respectively. Four (4) patients were neonates, and 10 were older infants. Twelve (12) patients had cardiomyopathy and two, myocarditis. Preoperative extracorporeal membrane oxygenation (ECMO) support was required in six patients for a mean of 9 days (IQR 6-13). Sepsis occurred in five patients (36%) and thromboembolic stroke in two patients (14%). Survival to bridge to transplantation (11) and recovery (1) was achieved in 12 patients (86%). Mortality was 14%. The median duration of BHE support was 110 days (IQR 40-161). Both patients who died were neonates with myocarditis and required surgical re-intervention during BHE support. CONCLUSIONS: BHE provides excellent support as a bridge to transplantation or recovery in infants, with a low incidence of neurological dysfunction. Neonates with myocarditis may be at greater risk for death after BHE implantation.

Single-ventricle palliation in children with atrioventricular septal defect and transposition of the great arteries: 45 years of experience.

BACKGROUND: The association of atrioventricular septal defect and transposition of the great arteries is very rare. As a rule, these patients have unbalanced ventricles. However, there have been no studies describing the results of single-ventricle palliation in these children. METHODS: All children who underwent surgery with a diagnosis of atrioventricular septal defect and transposition of the great arteries were included in the study. Data were obtained from medical records. RESULTS: A total of 38 patients with atrioventricular septal defect and transposition of the great arteries underwent single-ventricle palliation at the study institution between 1971 and 2016. The mean follow-up was 12.4 years (median: 14.6 years, range 2-43.3 years). Most children had unbalanced atrioventricular septal defect (94.7%, 36/38). Survival was 67.6% (95% confidence interval [CI]: 50.0-80.2%) at 10 years and 57.8% (95% CI: 38.0-73.4%) at 20 years. By 10 years, 58.6% (95% CI: 40.8-72.7%) had progressed to Fontan completion, while 32.5% (95% CI: 18.2-47.6%) had died. In patients achieving Fontan completion, 20-year event-free survival was 73.3% (95% CI: 34.8-91.3%), while 5.0% (95% CI: 0.4-20.5%) had undergone cardiac transplantation and 21.7% (95% CI: 3.2-50.8%) had undergone takedown of the Fontan circulation. Freedom from atrioventricular valve surgery was 57.0% (95% CI: 37.2-72.7%) at 10 and 20 years. CONCLUSIONS: The association of atrioventricular septal defect and transposition of the great arteries is very rare, and most of these children have unbalanced ventricles. Single-ventricle palliation results in 25-year overall survival of 50%. However, in patients, who had Fontan completion, survival was 75% at 25 years after Fontan operation.

Rare Association of an Intramural Coronary Artery and Truncus Arteriosus.

The association of truncus arteriosus (TA) and an intramural coronary artery is rare. Seven (7) patients had TA and an intramural coronary artery at the Royal Children's Hospital, Melbourne between 1996 and 2018. Four (4) patients underwent concomitant unroofing of their intramural coronary artery. One (1) patient who did not undergo concomitant unroofing had a cardiac arrest on postoperative day 1 and subsequently underwent reoperation for coronary unroofing. Given the potential for serious complications, patients with TA and an intramural coronary artery may benefit from coronary unroofing with creation of a generous neo-ostium.

Quality of life in adult survivors after paediatric heart transplantation in Australia.

BACKGROUND: Paediatric heart transplantation in Australia is centralised at The Royal Children's Hospital, Melbourne. Survival to adulthood is improving but the ongoing need for complex medical therapy, surveillance, and potential for late complications continues to impact on quality of life. Quality of life in adults who underwent heart transplantation in childhood in Australia has not been assessed. METHODS: Cross-sectional quality of life data were collected from paediatric heart transplant survivors >18 years of age using Rand 36-Item Health Survey. Self-reported raw scores were transformed to a 0-100 scale with higher scores indicating better quality of life. Mean scores were compared to National Health Survey Short Form-36 Population Norms data using the independent sample t-test. RESULTS: A total of 64 patients (64/151) who underwent transplantation at The Royal Children's Hospital between 1988 and 2016 survived to adulthood. In total 51 patients (51/64, 80%) were alive at the time of the study and 27 (53%) responded with a mean age of 25 ± 6 years, being a median of 11 years (interquartile range 7-19) post-transplantation. Most self-reported quality of life subscale scores were not significantly different from the Australian normative population data. However, self-reported 'General Health' was significantly worse than normative data (p = 0.02). Overall, 93% (25/27) reported their general health as being the same or better compared to 1-year ago. CONCLUSION: Adult survivors after paediatric heart transplantation in Australia report good quality of life in multiple domains and demonstrate independence in activities of daily living and employment. However, lifelong medical treatment may affect perceptions of general health.

Dismal Outcomes of Second-Run Extracorporeal Life Support in the Paediatric Population.

BACKGROUND: In 2011 we reported unfavourable outcomes of second-run extracorporeal life support (ECLS) in children. We wanted to investigate whether this previous report affected our strategy and modified our long-term outcomes. METHODS: Between 1988 and 2015, 31 patients underwent a second-run ECLS. Median age at the time of first support was 9days (0-16 years). Median length of support for the first and second runs were 4.7days (0.1-10) and 3.6days (0.5-8.7) respectively, with an interval of 1.8days (0.1-66) between supports. RESULTS: There was an increasing trend in the number of patients undergoing second-run ECLS after our report: 21 patients between 1988 and mid-2010 (0.9 patients/year) and 10 between mid-2010 and 2015 (two patients/year) (p=0.06). However, among all the patients who underwent ECLS, the proportion of second-run ECLS was not different before and after 2010 (4% vs. 4.2% respectively, p=0.92). While 58% of patients (18/31) survived weaning of support, only 23% (7/31) survived to hospital discharge and 14% (5/31) were still alive after hospital discharge at a median of 6.5 years (1.2-11.6). The three patients who had positive long-term outcomes had the second-run ECLS instituted to allow for major cardiac operations. CONCLUSIONS: Compassionate use of second-run ECLS is difficult to refuse but one should be aware that its outcomes are dismal. In our centre, benefits seem to be limited to cases where the second-run ECLS allows for a major cardiac intervention.

Major Device-Dependence of Measured Hypertensive Status From 24-Hour Ambulatory Blood Pressure Monitoring After Aortic Coarctation Repair.

BACKGROUND: Twenty-four-hour (24-hr) ambulatory blood pressure monitoring (ABPM) is often considered the gold standard to detect hypertension. We aimed to determine the short-term progression of 24-hour blood pressure after coarctation repair and to compare ABPM between two different devices. METHODS: We performed a cross-sectional study using 24-hour ABPM (Oscar 2) in 47 patients aged 16-48 years with previous paediatric coarctation repair and not on antihypertensive medication. Results were compared to a previous ABPM using paired analyses. A subset (10/47, 21%) had an additional previous ABPM performed using a Spacelabs device. RESULTS: After a mean follow-up of 27±6 years after repair, hypertension and prehypertension on Oscar 2 ABPM was present in 57% (27/47) and 11% (5/47), respectively. Mean follow-up time between Oscar 2 ABPMs was 3.9±1.4 years, and between first Oscar 2 and Spacelabs and between Spacelabs and second Oscar 2 ABPM was 1.4±0.8 and 1.8±0.3 years, respectively. There was no difference in the proportion of hypertensive patients between Oscar 2 ABPMs (55% [26/47] vs. 57% [27/47], p=1.0) but 17 patients (17/47, 36%) had a reclassification of 24-hour ABPM status. Mean 24-hour systolic blood pressure was higher in both Oscar 2 ABPMs compared to Spacelabs (142.4±11.7 vs. 120.4±11.8mmHg, p=0.0001; and 137.4±12.2 vs. 120.4±11.8mmHg, p=0.0001; respectively). CONCLUSION: There was high intra-device reproducibility of 24-hour ABPM results using an Oscar 2 device but poor inter-device reproducibility in patients with repaired coarctation. Device-specific reference values may be required to ensure reliable 24-hour ABPM interpretation.

Chylothorax following paediatric cardiac surgery: a case-control study.

OBJECTIVES: The aims of this study were to investigate risk factors for the development of postoperative chylothorax following paediatric congenital heart surgery and to investigate the impact of a management guideline on management strategies and patient outcome. METHODS: All patients with chylothorax following cardiac surgery at the Royal Children's Hospital, Melbourne, over a 48-month period beginning in January 2008 were identified. A control group, matched for age, date of surgery, and sex, was identified. To investigate potential risk factors, univariable and multivariable logistic regression models were constructed with paired analysis. To examine the effect of a standardised management protocol, data before and after the implementation of the guideline were compared. RESULTS: In total, 121 cases of chylothorax were identified, with 121 controls, matched for age at surgery, date of surgery, and sex. The incidence of chylothorax was 5.23%. Increasing surgical complexity (univariable OR 0.17 for the least complex versus the most complex group, p=0.02), closed-heart surgeries (OR 0.07 for open versus closed, p<0.001), and redo chest incisions (OR 10.0 for redo versus virgin, p<0.001) were significantly associated with chylothorax. The standardised management protocol had no significant impact on either drainage duration or management strategy. CONCLUSIONS: We have replicated the previously reported association between surgical complexity and chylothorax risk, and have shown, for the first time, that redo chest openings are also associated with a significantly increased risk. The implementation of a standardised management protocol in our institution did not result in a significant change in either chylothorax drainage duration or management strategy.

Impact of the location of the fenestration on Fontan circulation haemodynamics: a three-dimensional, computational model study.

OBJECTIVES: There is no consensus or theoretical explanation regarding the optimal location for the fenestration during the Fontan operation. We investigated the impact of the location of the fenestration on Fontan haemodynamics using a three-dimensional Fontan model in various physiological conditions. METHODS: A three-dimensional Fontan model was constructed on the basis of CT images, and a 4-mm-diameter fenestration was located between the extracardiac Fontan conduit and the right atrium at three positions: superior, middle, and inferior part of the conduit. Haemodynamics in the Fontan route were analysed using a three-dimensional computational fluid dynamic model in realistic physiological conditions, which were predicted using a lumped parameter model of the cardiovascular system. The respiratory effect of the caval flow was taken into account. The flow rate through the fenestration, the effect of lowering the central venous pressure, and wall shear stress in the Fontan circuit were evaluated under central venous pressures of 10, 15, and 20 mmHg. The pulse power index and pulsatile energy loss index were calculated as energy loss indices. RESULTS: Under all central venous pressures, the middle-part fenestration demonstrated the most significant effect on enhancing the flow rate through the fenestration while lowering the central venous pressure. The middle-part fenestration produced the highest time-averaged wall shear stress, pressure pulse index, and pulsatile energy loss index. CONCLUSIONS: Despite slightly elevated energy loss, the middle-part fenestration most significantly increased cardiac output and lowered central venous pressure under respiration in the Fontan circulation.

Partnership models for the establishment of sustainable paediatric cardiac surgical and cardiac intensive care programmes in low- and middle-income countries.

The care of patients with CHD remains a challenge in low- and middle-income countries. Their health systems have not been able to achieve consistently high performance in this field. The large volume of patients, manpower constraints, inconsistencies in the level and type of background training of the teams caring for this patient population, and the inadequate quality control systems are some of the barriers to achieving excellence of care. We describe three different international projects supporting the paediatric cardiac surgical and paediatric cardiac intensive care programmes in Latin America, Asia, and the Caribbean.

Outcomes of Subaortic Obstruction Resection in Children.

BACKGROUND: Studies of long-term outcomes of discrete subaortic stenosis are rare. Therefore, we reviewed the long-term outcomes of fibromuscular resection in children with subaortic stenosis over 26 years from a single institution. METHODS: We conducted a retrospective review of all children (n=72) who underwent resection of subaortic obstruction for discrete subaortic stenosis between 1989 and 2015. RESULTS: Median age at surgery was 5.0 years (2.7-7.6 years). There were no operative deaths but three late deaths (4.2%, 3/72). Overall Kaplan-Meier survival at 10 years was 93.0 ± 3.9% (95% CI: 79.6, 97.7). Peak instantaneous left ventricular outflow tract Doppler gradient decreased from 74.2±36.7mmHg (16.0-242.0mmHg) preoperatively to 12.8±7.4mmHg (2.6-36.0mmHg) postoperatively (p<0.001). Mean left ventricular outflow tract Doppler gradient decreased from 42.4±17.2mmHg (12.0-98.0) preoperatively to 7.5±2.7mmHg (1.4-19.3mmHg) postoperatively (p<0.001). However, over the mean follow-up period of 7.8±6.1 years (0.1-25.2 years), 29.0% (20/69) of patients had recurrence and 18.8% (13/69) required reoperation at median time of 4.8 years (3.1-9.1 years) after the initial repair. Freedom from reoperation at 10 years was 71.1±7.1% (95% CI: 54.6, 82.3). Risk factors for reoperation were age less than five years at initial repair (p=0.036) and extension of the membrane to the aortic valve (p=0.001). Aortic insufficiency was present in 54.2% (39/72) of patients preoperatively. Progression of aortic insufficiency occurred in 38.9% (28/72). Involvement of the aortic valve at initial repair was associated with need for subsequent aortic valve repair or replacement (p=0.01). CONCLUSIONS: Resection of subaortic obstruction is associated with low mortality and morbidity. Recurrence and reoperation rates are high and progression of aortic insufficiency following subaortic resection is common. Therefore, these patients warrant close follow-up into adult life.

Elective decompression of the left ventricle in pediatric patients may reduce the duration of venoarterial extracorporeal membrane oxygenation.

We aimed to determine the effect of elective left heart decompression at the time of initiation of central venoarterial extracorporeal membrane oxygenation (VA ECMO) on VA ECMO duration and clinical outcomes in children in a single tertiary ECMO referral center with a large pediatric population from a national referral center for pediatric cardiac surgery. We studied 51 episodes of VA ECMO in a historical cohort of 49 pediatric patients treated between the years 1990 and 2013 in the Paediatric Intensive Care Unit (PICU) of the Royal Children's Hospital, Melbourne. The cases had a variety of diagnoses including congenital cardiac abnormalities, sepsis, myocarditis, and cardiomyopathy. Left heart decompression as an elective treatment or an emergency intervention for left heart distension was effectively achieved by a number of methods, including left atrial venting, blade atrial septostomy, and left ventricular cannulation. Elective left heart decompression was associated with a reduction in time on ECMO (128 h) when compared with emergency decompression (236 h) (P = 0.013). Subgroup analysis showed that ECMO duration was greatest in noncardiac patients (elective 138 h, emergency 295 h; P = 0.02) and in patients who died despite both emergency decompression and ECMO (elective 133 h, emergency 354 h; P = 0.002). As the emergency cases had a lower pH, a higher PaCO2 , and a lower oxygenation index and were treated with a higher mean airway pressure, positive end-expiratory pressure, and respiratory rate prior to receiving VA ECMO, we undertook multivariate linear regression modeling to show that only PaCO2 and the timing of left heart decompression were associated with ECMO duration. However, elective left heart decompression was not associated with a reduction in length of PICU stay, duration of mechanical ventilation, or duration of oxygen therapy. Elective left heart decompression was not associated with improved ECMO survival or survival to PICU discharge. Elective left heart decompression may reduce ECMO duration and has therefore the potential to reduce ECMO-related complications. A prospective, randomized controlled trial is indicated to study this intervention further.