Matthew S. Yong

Outcomes of Surgery for Simple Total Anomalous Pulmonary Venous Drainage in Neonates

BACKGROUND Repair of total anomalous pulmonary venous drainage (TAPVD) in neonates remains a challenge as it is often associated with severe obstruction. We describe a large cohort of neonates who underwent TAPVD repair at a single institution. METHODS From 1973 to 2008, 112 patients underwent simple TAPVD surgery during the first month of life. Data collection occurred retrospectively. RESULTS Preoperative pulmonary venous obstruction (PVO) occurred in 89 (79.5%) patients. There were 12 (10.7%) early deaths. Significant risk factors were bypass time greater than 65 minutes (p=0.014) and emergent surgery (p=0.005). Hospital mortality was unchanged throughout the 3 eras (1973 to 1988, 1989 to 1998, 1999 to 2008), despite an increase in patients with preoperative acidosis (p=0.004) and severe TAPVD obstruction (p=0.038) during the recent 10 years. There were 6 (6.25%) late deaths within 2 years of repair. Survival at 20 years was 83.4% (95% confidence interval 75 to 89). Risk factors for late death were operative weight 2.5 kg or less (p=0.004) and postoperative pulmonary hypertensive crisis (p=0.02). Reoperation for recurrent PVO was required in 13 patients (11.9%). Risk factors were operative weight 2.5 kg or less (p=0.035) and postoperative pulmonary hypertensive crisis (p=0.002). Follow-up was 96% complete and survivors (n=90) were asymptomatic at a median age of 11.7 years. CONCLUSIONS Hospital mortality remained unchanged over the 36-year period. Survival beyond 2 years offers excellent outcome. Risk factors for mortality were the preoperative clinical status, prolonged bypass time, persisting micro-obstruction, and low operative weight. A reduction in mortality will likely require development of effective medical management for patients who have peripheral PVO not amenable to surgical repair.

Effect of Remote Ischemic Preconditioning on Phosphorylated Protein Signaling in Children Undergoing Tetralogy of Fallot Repair: A Randomized Controlled Trial

Background Our previous randomized controlled trial demonstrated cardiorespiratory protection by remote ischemic preconditioning (RIPC) in children before cardiac surgery. However, the impact of RIPC on myocardial prosurvival intracellular signaling remains unknown in cyanosis. RIPC may augment phosphorylated protein signaling in myocardium and circulating leukocytes during tetralogy of Fallot (ToF) repair. Methods and Results Children (n=40) undergoing ToF repair were double‐blind randomized to RIPC (n=11 boys, 9 girls) or control (sham RIPC: n=9 boys, 11 girls). Blood samples were taken before, immediately after, and 24 hours after cardiopulmonary bypass. Resected right ventricular outflow tract muscle and leukocytes were processed for protein expression and mitochondrial respiration. There was no difference in age (7.1±3.4 versus 7.1±3.4 months), weight (7.7±1.8 versus 7.5±1.9 kg), or bypass or aortic cross‐clamp times between the groups (control versus RIPC, mean±SD). No differences were seen between the groups for an increase in the ratio of phosphorylated to total protein for protein kinase B, p38 mitogen activated protein kinase, signal transducer and activator of transcription 3, glycogen synthase kinase 3β, heat shock protein 27, Connexin43, or markers associated with promotion of necrosis (serum cardiac troponin I), apoptosis (Bax, Bcl‐2), and autophagy (Parkin, Beclin‐1, LC3B). A high proportion of total proteins were in phosphorylated form in control and RIPC myocardium. In leukocytes, mitochondrial respiration and assessed protein levels did not differ between groups. Conclusions In patients with cyanotic heart disease, a high proportion of proteins are in phosphorylated form. RIPC does not further enhance phosphorylated protein signaling in myocardium or circulating leukocytes in children undergoing ToF repair. Clinical Trial Registration URL: (http://www.anzctr.org.au/trial_view.aspx?id=335613. Unique identifier: Australian New Zealand Clinical Trials Registry number ACTRN12610000496011.

Long-term outcomes of patients with absent pulmonary valve syndrome: 38 years of experience.

BACKGROUND Absent pulmonary valve syndrome is associated with aneurysmal dilatation of the pulmonary arteries and compression of the tracheobronchial tree and may lead to significant respiratory compromise. We describe the outcomes of surgical correction of absent pulmonary valve syndrome and risk factors for mortality and reoperation. METHODS A review of 52 patients with absent pulmonary valve syndrome who underwent surgical correction between 1975 and 2013 was conducted. The median age and weight at repair were 9 months (range, 4 days to 24.2 years) and 6.9 kg (range, 1.8 to 56 kg). Preoperative intubation was required in 15 patients (29%), and 21 patients (40%) underwent urgent repair. The pulmonary valve was replaced with a valved conduit in 16 patients (31%) or monocusp valve in 16 patients (31%). Valveless repair was performed in 20 patients (38%). Pulmonary artery reduction was performed in 39 patients (75%), and 2 patients (4%) underwent a Lecompte maneuver. RESULTS The median follow-up time was 13 years (range, 1 month to 35 years). Early mortality was 18.8% (3 of 16) during 1975 through 1989, 19% (4 of 21) during 1990 through 2000, and 0% (0 of 15) during 2001 through 2013. Late mortality was 6.7% (3 of 45). Overall survival at 5, 10, and 20 years was 81.4%±5.6%. On multivariate analysis, preoperative ventilation (p=0.009) was the only risk factor for overall mortality. Freedom from late reoperation at 5, 10, and 20 years was 79.7%±6.9%, 69.4%±8.2%, and 52.1%±9.8%, respectively. No difference in reoperation rates was found between valved conduit, monocusp, or valveless techniques. Risk factors for late reoperation on multivariate analysis were prematurity (p=0.001) and neonatal primary repair (p=0.007). Longer postoperative ventilation periods were predicted by preoperative ventilation (p<0.001) and surgery during infancy (p=0.01). CONCLUSIONS Long-term survival for absent pulmonary valve syndrome has improved during the last decade. Preoperative ventilation predicted longer postoperative ventilation and mortality.

Heart transplantation in Fontan patients across Australia and New Zealand

Objective Patients with Fontan physiology may eventually require heart transplantation (HT). We determined the rates and outcomes of HT in a national, population-based multicentre study. Methods From 1990 to 2015, 1369 patients underwent the Fontan procedure as recorded in the Australia and New Zealand Fontan Registry. We identified those who underwent HT and analysed their outcomes. We compared rates of HT between two catchment areas. In area 1 (n=721), patients were referred to the national paediatric HT programme or its associated adult programme. In area 2 (n=648), patients were referred to the national paediatric HT programme or one of the other adult HT programmes. Results Mean follow-up time post-Fontan was 11±8 years. Freedom from Fontan failure was 74%±3.9% at 20 years. HT was performed in 34 patients. Patients living in area 1 were more likely to have HT (4.0%, 29/721 vs 0.8%, 5/648, p<0.001) with a cumulative proportion of 3.4% vs 0.7% at 10 years and 6.8% vs 1.2% at 20 years (p=0.002). Area 1 patients were more likely to undergo HT (hazard ratio 4.7, 95% CI 1.7 to 13.5, p=0.003) on multivariable regression. Post-HT survival at 1, 5 and 10 years was 91%, 78% and 71%, respectively. Compared with other patients with congenital heart disease (n=87), Fontan patients had similar in-hospital outcomes and long-term survival. Conclusions Although HT after the Fontan procedure can be achieved with excellent outcomes, most patients with Fontan failure do not undergo HT. Significant regional differences in rates of HT in Fontan patients exist.

Outcomes of repair of complete atrioventricular septal defect in the current era

OBJECTIVES We sought to evaluate the surgical outcomes of the repair of complete atrioventricular septal defects (cAVSDs) in our institution in the current era. METHODS From 2000 to 2011, 138 patients underwent definitive repair of cAVSD. Repair was performed using a two-patch technique in 92.0% of patients and one-patch technique in 2.2%, and the ventricular septal component was closed directly in 5.8% of patients. RESULTS Operative mortality was 1.4% (2 of 138). Overall mortality was 5.8% (8 of 138). Follow-up was 96% complete. Freedom from reoperation was 84.3% (95% CI 77.1-91.5%) at 8 years. Age >6 months at repair was associated with higher rates of reoperation (P = 0.001; HR 6.85; 95% CI 2.30-20.44). However, operating at <6 months of age was associated with longer intensive care unit stay (P = 0.019; median 2.7 vs 1.4 days), mechanical ventilation (P = 0.001; median 1.7 vs 0.9 days) and postoperative hospital stay (P = 0.016; median 8 vs 5 days). Moderate or greater left atrioventricular valvular regurgitation (LAVVR) at discharge was a risk factor for reoperation (P < 0.001; HR 10.85; 95% CI 3.75-31.40). CONCLUSIONS Repair of cAVSD carries low mortality, but a moderate reoperation rate. An optimal time for repair of the cAVSD is between 3 and 6 months of age. Repair prior to 3 months of age and the need for cleft closure were associated with a higher degree of LAVVR at discharge. Greater LAVVR at discharge is a risk factor for reoperation regardless of age at initial repair. In the current era, Downs syndrome is not a risk factor for reoperation.

Ross Procedure in Children: 17‐Year Experience at a Single Institution

Background The Ross procedure in children carries substantial mortality and reoperation rate. Aortic root dilatation is of concern. To prevent dilatation of the neoaortic root, but permit normal growth, we began to apply an absorbable poly‐(p‐dioxanone)‐filaments (PDS) band at the sino‐tubular (ST)‐junction. Methods and Results All children (n=100) who underwent Ross procedure during 1995–2012 were studied. Mean age at operation was 8.6±6.1 years (median 8.3 years, range 3 days to 18 years); 19 patients were younger than 1 year of age. The root replacement (n=91, Ross‐Konno procedure in 29 patients), root inclusion (n=6), and subcoronary implantation (n=3) techniques were used. Operative mortality was 6% (6/100, 4 neonates, 2 infants). Age of <1‐year at time of operation was a risk factor for early death (P<0.001). Mean follow‐up time was 7.0±4.8 years (median 7.4 years, range 5 days to 16 years). Late mortality was 4.3% (4/94). Freedom from moderate or greater neoaortic valve insufficiency (AI) at 5 and 10 years was 89% and 83%, respectively. Freedom from neoaortic valve reoperation at 5 and 10 years was 96% and 86%, respectively. Aortic dilatation to Z‐score >4 was greatest at the ST‐junction (23%, 11/48) compared to the aortic annulus (17%, 11/66) and sinuses (14%, 7/50). Since 2001, a PDS band was placed around the ST‐junction in 19 patients. Survivors with the PDS band had less AI (0 versus 20%, P=0.043) compared to survivors (n=35) without the PDS at 4.1±3 years. Conclusions The Ross procedure in children can be performed with acceptable results. Children younger than 1 year of age have higher mortality, but not an increased autograft reoperation rate. Stabilization of the ST‐junction may reduce AI.

Outcomes of Atrioventricular Valve Operation in Patients With Fontan Circulation

BACKGROUND Data on outcomes of atrioventricular (AV) valve surgical procedures in patients with Fontan circulation are limited. METHODS We conducted a retrospective review of all children with Fontan circulation who underwent AV valve operations. RESULTS From 1981 to 2014, 581 patients underwent Fontan operations, and 9.3% (54/581) of them required AV valve operations. The first AV valve operation was performed before (n = 32), during (n = 15), or after (n = 7) the Fontan operation. The mean follow-up time was 9.8 ± 7.1 years (range, 6 months to 32 years). Operative mortality for the initial AV valve operation was 1.9% (1/54) and occurred in a patient who had the initial valve operation concomitantly with the Fontan. Late mortality was 5.7% (3/53). Heart transplantation was performed in 13.0% (7/54) of patients. Freedom from death or transplantation after the first AV valve operation was 89.8 ± 4.4% at 5 years (95% confidence interval [CI], 77.1 to 95.6) and 81.0 ± 6.2% at 10 years (95% CI, 65.0 to 90.2). Reoperation on the AV valve was performed in 44.4% (24/54) of patients. The median time to initial valve reoperation was 3.1 years (interquartile range, 0.8 to 7.4 years). Freedom from reoperation or transplantation was 63.4 ± 7.0% at 5 years (95% CI, 48.2 to 75.3) and 48.9 ± 7.9% at 10 years (95% CI, 32.8 to 63.2). Freedom from moderate or more regurgitation in patients who had not undergone reoperation or transplantation was 74.0 ± 6.9% (95% CI, 57.5 to 84.8) at 5 years and 67.5 ± 7.7% (95% CI:,50.0 to 80.0) at 10 years. After initial valve operation, thromboembolic events occurred in 13.0% (7/54) of patients, stroke occurred in 24.1% (13/54) of patients, pacemaker insertion was required in 16.7% (9/54) of patients, and protein-losing enteropathy was diagnosed in 7.4% (4/54) of patients. Of the 43 surviving transplant-free patients, 62.8% (27/43) were in New York Heart Association (NYHA) class I, 34.9% (15/43) were in NYHA class II, and 1 patient was in NYHA class III. CONCLUSIONS The AV valve operation done before, during, or after the Fontan operation is associated with low operative mortality but a high reoperation rate with significant risk of late death, transplantation, and persistent AV valve regurgitation.

Surgical management of pulmonary artery sling in children

OBJECTIVES Pulmonary artery (PA) sling is a rare vascular anomaly associated with congenital tracheal stenosis. The natural history is poor and these patients often require early surgical intervention. We describe our experience with repair of this condition. METHODS From 1984 to 2011, 21 patients with PA sling underwent repair at the Royal Childrens Hospital (median age, 5.9 months). PA sling was associated with compression of the trachea in all patients. Tracheal surgery was required in 12 (57.1%) patients. All patients had an echocardiogram, and concomitant repair of coexisting cardiac anomalies was performed in 6 (28.6%, 6/21) patients. RESULTS Operative mortality was 14.3% (3/21), occurring at 19 days, 4.4 months, and 5 months after surgery. Operative mortality for the first 10 years was 22.2% (1984-1993; 2/9), the next 10 years was 14.3% (1994-2003; 1/7), and 0% for the most recent 7 years (2004-2011; 0/5). All deaths occurred in patients requiring tracheal repair (25%, 3/12). No deaths have occurred since 2004 with introduction of the slide tracheoplasty technique. One (5.6%, 1/18) late death occurred at 8 months after repair. After tracheal repair, intervention for excessive granulations and tracheomalacia was necessary in 6 (50%, 6/12) patients. Median follow-up was 8 years (mean, 8.6 ± 6.4 years; range, 5 months to 20.6 years), and all survivors (100%, 17/17) remain asymptomatic. CONCLUSIONS Children with PA sling who do not require tracheal surgery have excellent outcomes. Mortality is determined by the need for tracheal surgery. However, with the advent of the slide tracheoplasty technique, mortality can be reduced. Survival beyond 1 year after surgery offers excellent prognosis.

Outcomes of Truncus Arteriosus Repair in Children: 35 Years of Experience From a Single Institution

We evaluated the long-term outcomes following repair of truncus arteriosus (TA) from a single institution. We conducted a retrospective review of children (n = 171) who underwent TA repair between 1979 and 2014. Early mortality rate was 11.7% (20/171). There were 19 late deaths. Most deaths (74%, 29/39) occurred within the first year following surgery. The 1-year mortality rate in 1979-2004 was 18% (25/136) and decreased to 11% (4/35) in 2005-2014. The overall survival rate was 73.6% at 30 years. Multivariate analysis identified postoperative extracorporeal membrane oxygenation (P = 0.003), operative weight <2.5kg (P = 0.012), prior surgical intervention (P = 0.018), and coronary artery anomaly (P = 0.037) as risk factors for early mortality. A Cox regression model identified DiGeorge syndrome (P = 0.008) as a risk factor for late mortality. Freedom from right ventricular outflow tract reoperation was 4.6% at 20 years. Concomitant truncal valve (TV) repair or replacement was undertaken in 20 patients. Additionally, 14 patients underwent late TV repair or replacement. The overall survival rate in patients who underwent TV operation was 76.9% at 20 years. A total of 19 patients had concomitant interrupted aortic arch with a survival rate of 89.5% at 20 years. Median follow-up was 19 years (mean = 17 years, range: 1-34 years). All patients were in New York Heart Association Class I/II at last follow-up. Following repair of TA, patients had good long-term functional status but had high reoperation rates. Repair of interrupted aortic arch and TV were not risk factors for mortality. Postoperative extracorporeal membrane oxygenation, operative weight <2.5kg, prior surgical intervention, and coronary artery anomaly were risk factors for early death. DiGeorge syndrome was associated with late death, most commonly from infection.

Surgical management of tricuspid valve endocarditis in the current era: A review

The incidence of isolated tricuspid valve infective endocarditis is increasing. Medical management is the mainstay of treatment but surgical intervention is required in a subset of patients. Surgical treatment options include valve excision and replacement or valve reconstruction. We searched PubMed and the Cochrane library to identify articles to be included in this review of surgical outcomes. References of selected articles were crosschecked for other relevant studies. Surgical management of tricuspid valve endocarditis can be achieved with satisfactory outcomes. However, the optimal indication and timing of surgery remain unclear, and the frequent association with intravenous drug use complicates management. Repair techniques are preferable though there is no clear evidence supporting one method over another.