The Yasui operation: A single institutional experience over 30 years

Objective

The Yasui operation was introduced in 1987 for patients with 2 adequate ventricles, a ventricular septal defect, and aortic atresia or interrupted aortic arch. Despite promising early outcomes, left ventricular outflow tract obstruction (LVOTO) remains a long-term concern. The purpose of this study is to report our institutional experience with the Yasui operation.

Methods

We retrospectively reviewed all patients undergoing the Yasui operation between 1989 and 2021. Results are reported as median with interquartile range (IQR).

Results

Twenty-five patients underwent a Yasui operation (19 primary), at 11 days (IQR, 7-218 days) of life and weight of 3 kg (IQR, 2.8-4.1 days). Fundamental diagnosis was ventricular septal defect/interrupted aortic arch in 11 patients and ventricular septal defect/aortic atresia in 14. Follow-up was 96% (24 out of 25) at 5 years (IQR, 1.4-14.7) with 92% survival. Freedom from LVOTO reoperation was 91% at late follow-up with 2 patients requiring baffle revision at 6 and 9 years. Latest echocardiogram showed 100% of patients had normal biventricular function and 87% (20 out of 23) less than mild LVOTO at 5 years (IQR, 2.3-14.9). Diagnosis, aortic valve morphology, and material used were not predictors of LVOTO. Freedom from right ventricle-to-pulmonary artery conduit reoperation was 48% at a median of 5 years (IQR, 1.4-14.7). Conduit type was not a predictor of reintervention.

Conclusions

The Yasui operation can be performed with low morbidity and mortality in patients with 2 acceptable-size ventricles and aortic atresia or interrupted aortic arch with severe LVOTO. Despite some burden of reoperation, midterm reoperation for LVOTO is not common and ventricular function is preserved.

Endothelial-to-Mesenchymal Transition as Underlying Mechanism for the Formation of Double-Chambered Right Ventricle

Double-chambered right ventricle (DCRV) is a progressive division of the right ventricular outflow tract (RVOT) often associated with a subaortic ventricular defect (VSD). The septation is caused by a mixture of hypertrophied muscle bundles and fibrous tissue, whereof the latter is of unclear pathogenesis. Our group has previously reported that flow disturbances lead to formation of fibroelastic tissue through a process called endothelial-to-mesenchymal transition (EndMT) but it is unclear whether the same mechanism exists in the RV. Tissue from patients undergoing repair of DCRV was examined to identify the histomorphological substrate of this tissue. Demographic and pre-/post-operative echocardiographic data were collected from nine patients undergoing surgery for DCRV. RVOTO tissue samples were histologically analyzed for myocardial hypertrophy, fibrosis, elastin content, and active EndMT (immunohistochemical double-staining for endothelial and mesenchymal markers and transcription factors Slug/Snail) and compared to four healthy controls. Indication for surgery were symptoms and progressive RVOT gradients. A highly turbulent flow jet through the RVOTO and VSD was observed in all patients with a preoperative median RVOT peak gradient of 77 mmHg (IQR 55.0-91.5), improved to 6 mmHg (IQR 4.5-17) postoperatively. Histological analysis revealed muscle and thick infiltratively growing fibroelastic tissue. EndMT was confirmed as underlying patho-mechanism of this fibroelastic tissue but the degree of myocardial hypertrophy was not different compared to controls (P = 0.08). This study shows for the first time that an invasive fibroelastic remodeling processes of the endocardium into the underlying myocardium through activation of EndMT contributes to the septation of the RVOT.

Impact of surgical pulmonary valve replacement on ventricular strain and synchrony in patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance feature tracking study

BACKGROUND

In patients with repaired tetralogy of Fallot (TOF), a better understanding of the impact of surgical pulmonary valve replacement (PVR) on ventricular mechanics may lead to improved indications and outcomes. Therefore, we used cardiovascular magnetic resonance (CMR) feature tracking analysis to quantify ventricular strain and synchrony in repaired TOF patients before and after PVR.

METHODS

Thirty-six repaired TOF patients (median age 22.4 years) prospectively underwent CMR a mean of 4.5 ± 3.8 months before PVR surgery and 7.3 ± 2.1 months after PVR surgery. Feature tracking analysis on cine steady-state free precession images was used to measure right ventricular (RV) and left ventricular (LV) circumferential strain from short-axis views at basal, mid-ventricular, and apical levels; and longitudinal strain from 4-chamber views. Intraventricular synchrony was quantified using the maximum difference in time-to-peak strain, the standard deviation of the time-to-peak, and cross correlation delay (CCD) metrics; interventricular synchrony was assessed using the CCD metric.

RESULTS

Following PVR, RV end-diastolic volume, end-systolic volume, and ejection fraction declined, and LV end-diastolic volume and end-systolic volume both increased with no significant change in the LV ejection fraction. LV global basal and apical circumferential strains, and basal synchrony improved. RV global circumferential and longitudinal strains were unchanged, and there was a varied impact on synchrony across the locations. Interventricular synchrony worsened at the midventricular level but was unchanged at the base and apex, and on 4-chamber views.

CONCLUSIONS

Surgical PVR in repaired TOF patients led to improved LV global strain and no change in RV global strain. LV and RV synchrony parameters improved or were unchanged, and interventricular synchrony worsened at the midventricular level.

Prenatal diagnosis of transposition of the great arteries over a 20-year period: improved but imperfect

OBJECTIVE

To evaluate temporal trends in the prenatal diagnosis of transposition of the great arteries with intact ventricular septum (TGA/IVS) and its impact on neonatal morbidity and mortality.

METHODS

We included in this study cohort newborns with TGA/IVS who were referred for surgical management to our center over a 20-year period (1992-2011). The study period was divided into five 4-year periods and the primary outcome was rate of prenatal diagnosis. Secondary outcomes included neonatal preoperative status and perioperative survival.

RESULTS

Of the 340 patients with TGA/IVS, 81 (23.8%) had a prenatal diagnosis. The rate of prenatal diagnosis increased over the study period, from 6% in 1992-1995 to 41% in 2008-2011 (P < 0.001). Compared to patients with a postnatal diagnosis, balloon atrial septostomy (BAS) was performed earlier in patients with a prenatal diagnosis (0 days after delivery vs 1 day after delivery, respectively; P < 0.001) and fewer prenatally diagnosed neonates required mechanical ventilation (55.6% vs 68.0%; P = 0.03). Between patients with a prenatal or postnatal diagnosis of TGA/IVS, there were no statistically significant differences in the incidence of preoperative acidosis (16.0% vs 25.5%; P = 0.1), need for preoperative extracorporeal membrane oxygenation (2.5% vs 2.7%; P = 1.0) or mortality (one preoperative and no postoperative deaths among prenatally diagnosed patients compared with four preoperative and six postoperative deaths among postnatally diagnosed patients).

CONCLUSIONS

The prenatal detection rate of TGA/IVS has improved but still remains below 50%, suggesting the need for strategies to increase detection rates. The mortality rate was not statistically significantly different between prenatally and postnatally diagnosed patients, however, there were significant preoperative differences with regard to earlier BAS and fewer neonates that required mechanical ventilation. Ongoing work is required to ascertain whether prenatal diagnosis confers long-term benefits.

The safety and efficacy of antifibrinolytic therapy in neonatal cardiac surgery

Background

Neonates undergoing open-heart surgery are particularly at risk of postoperative bleeding requiring blood transfusion. Aprotinin has attained high efficacy in reducing the requirement for a blood transfusion following a cardiopulmonary bypass, but is seldom studied in the neonatal age group. The aim of this study was to compare the efficacy and adverse effects of aprotinin and tranexamic acid in neonates undergoing open-heart surgery at a single centre.

Methods

Between October 2003 and March 2008, perioperative data of 552 consecutive neonatal patients undergoing open-heart surgery in Children’s Hospital Boston were reviewed. Among them, 177 did not receive antifibrinolytic therapy (Group A); 100 were treated with tranexamic acid only (Group B); and 275 patients received aprotinin with or without tranexamic acid (Group C). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained identical. Postoperative complications and in-hospital mortality were the primary study endpoints.

Results

Body weight and Risk Adjustment for Congenital Heart Surgery (RACHS-1) scores were statistically comparable among the three groups. No statistically significant differences were observed between the duration of hospitalization, chest tube drainage, reexploration for bleeding, and kidney function impairment. In Group C, less blood was transfused within 24 hours than in GroupB. Operative mortality was similar among the three groups.

Conclusion

No further risk and kidney injury were observed in the use of aprotinin in neonatal cardiac surgery, aprotinin demonstrated a reduced requirement for blood transfusion compared with tranexamic acid. Our data provide reasonable evidence that aprotinin and tranexamic acid are safe and efficacious as antifibrinolytic modalities in neonatal patients undergoing cardiac surgery.

Intraoperative adverse events can be compensated by technical performance in neonates and infants after cardiac surgery: a prospective study

OBJECTIVE

Our objective was to define the relationship between surgical technical performance score, intraoperative adverse events, and major postoperative adverse events in complex pediatric cardiac repairs.

METHOD

Infants younger than 6 months were prospectively followed up until discharge from the hospital. Technical performance scores were graded as optimal, adequate, or inadequate based on discharge echocardiograms and need for reintervention after initial surgery. Case complexity was determined by Risk Adjustment in Congenital Heart Surgery (RACHS-1) category, and preoperative illness severity was assessed by Pediatric Risk of Mortality (PRISM) III score. Intraoperative adverse events were prospectively monitored. Outcomes were analyzed using nonparametric methods and a logistic regression model.

RESULTS

A total of 166 patients (RACHS 4-6 [49%]), neonates [50%]) were observed. Sixty-one (37%) had at least 1 intraoperative adverse event, and 47 (28.3%) had at least 1 major postoperative adverse event. There was no correlation between intraoperative adverse events and RACHS, preoperative PRISM III, technical performance score, or postoperative adverse events on multivariate analysis. For the entire cohort, better technical performance score resulted in lower postoperative adverse events, lower postoperative PRISM, and lower length of stay and ventilation time (P < .001). Patients requiring intraoperative revisions fared as well as patients without, provided the technical score was at least adequate.

CONCLUSIONS

In neonatal and infant open heart repairs, technical performance score is one of the main predictors of postoperative morbidity. Outcomes are not affected by intraoperative adverse events, including surgical revisions, provided technical performance score is at least adequate.

Survival of children requiring repeat extracorporeal membrane oxygenation after congenital heart surgery

BACKGROUND

Clinical indications and outcomes for children requiring multiple extracorporeal membrane oxygenation (ECMO) runs during a single hospital admission are rarely reported. We review indications, cannulation techniques, and outcomes for infants requiring multiple ECMO runs after congenital heart surgery.

METHODS

Demographic and ECMO-related data for all children requiring multiple ECMO runs during a single hospital admission from 1995 to 2008 were extracted from our institution's ECMO database. Survival was defined as survival to hospital discharge. Demographic and ECMO data were compared between survivors and nonsurvivors using the Mann-Whitney test for continuous and Fisher's exact test for categorical data.

RESULTS

Twenty children (5% of 391 ECMO runs) with a median age of 5 days (range, 4 to 180 days) and weight of 3.22 kg required repeat ECMO support for persistent cardiopulmonary dysfunction despite successful weaning from an index ECMO run. Of the two-ventricle repair group, tetralogy of Fallot, truncus arteriosus, and transposition constituted the majority of cardiac diagnoses (75%), whereas single-ventricle physiology made up the rest (25%). The median total ECMO duration was 191 hours (range, 77 to 485 hours), and median hospital length of stay was 41 days (range, 6 to 297 days). Five (25%) patients survived to discharge. When survivors were compared with nonsurvivors, there were no significant differences in demographics, single or biventricular repair, indication for ECMO support, or need for surgical reoperation while on ECMO. However, the incidence of renal failure was higher in nonsurvivors than in survivors after multiple ECMO runs (12 versus 2.0; p=0.03).

CONCLUSIONS

Survival in children undergoing congenital heart surgery requiring multiple ECMO runs is low, but 1 in 4 patients will survive to discharge. If a correctable lesion or ventricular impairment is present, repeat ECMO support may be justified. Development of renal failure is associated with nonsurvival in these patients.

Randomized trial of pulmonary valve replacement with and without right ventricular remodeling surgery

BACKGROUND

Although pulmonary valve replacement (PVR) is effective in reducing right ventricular (RV) volume overload in patients with chronic pulmonary regurgitation, persistent RV dysfunction and subsequent adverse clinical outcomes have been reported. This trial was conducted to investigate whether the addition of surgical RV remodeling with exclusion of scar tissue to PVR would result in improved RV function and laboratory and clinical parameters, as compared with PVR alone.

METHODS AND RESULTS

Between February 2004 and October 2008, 64 patients who underwent RV outflow tract procedures in early childhood had more than or equal to moderate pulmonary regurgitation, and fulfilled defined criteria for PVR were randomly assigned to undergo either PVR alone (n=34) or PVR with surgical RV remodeling (n=30). No significant difference was observed in the primary outcome (change in RV ejection fraction, -2±7% in the PVR alone group and -1±7% in the PVR with RV remodeling group; P=0.38) or in any of the secondary outcomes at 6-month postoperative follow-up. Multivariable analysis of the entire cohort identified preoperative RV end-systolic volume index <90 mL/m(2) and QRS duration <140 ms to be associated with optimal postoperative outcome (normal RV size and function), and RV ejection fraction <45% and QRS duration ≥160 ms to be associated with suboptimal postoperative outcome (RV dilatation and dysfunction).

CONCLUSIONS

The addition of surgical remodeling of the RV to PVR in patients with chronic pulmonary regurgitation did not result in a measurable early benefit. Referral to PVR based on QRS duration, RV end-systolic volume, or RV ejection fraction may be beneficial. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00112320.

Evaluating failing Fontans for heart transplantation: predictors of death

BACKGROUND

Late complications of the Fontan operation represent a significant management challenge. Failing Fontan patients have two modes of presentation: impaired ventricular function (IVF) and those with preserved ventricular function (PVF) but with failing Fontan physiology (protein-losing enteropathy [PLE] and plastic bronchitis [PB]). This study evaluated whether failing Fontan patients referred for heart transplantation had a different outcome based on the mode of presentation.

METHODS

The medical records of all Fontan patients evaluated for heart transplantation at a single institution from 1994 to 2008 were retrospectively reviewed. Demographic, hemodynamic, and laboratory data were collected. Patients were stratified into an IVF or PVF group by echocardiographic criteria. Descriptive statistics and Kaplan-Meier analysis were used for hypothesis testing.

RESULTS

Thirty-four Fontan patients were evaluated for heart transplantation. According to echo description of systolic function, 18 were categorized as IVF and 16 as PVF. The IVF group had a significantly lower cardiac index and venous oxygen saturation, and significantly higher systemic vascular resistance vs the PVF group (p < 0.05). PLE or PB was present in 13 PVF patients and none in the IVF group. Twenty patients underwent transplantation, with similar rates amongst the IVF and PVF groups. Within 1 year from evaluation, 2 IVG patients and 7 PVF patients had died (p = 0.052).

CONCLUSIONS

Failing Fontan patients with PVF have decreased overall survival independent of whether they underwent transplantation. This trend indicates a need to improve the management and timing for transplantation amongst this population.

Regional Low-Flow Perfusion Versus Circulatory Arrest in Neonates: One-Year Neurodevelopmental Outcome

BACKGROUND

Regional low-flow perfusion of the brain is a bypass technique commonly used during stage 1 reconstruction in neonates with hypoplastic left heart syndrome and related variants. The neurodevelopmental outcome of these children is unknown.

METHODS

Twenty-nine infants (22 boys, 7 girls) with hypoplastic left heart syndrome or variant requiring single ventricle palliation and aortic arch reconstruction were studied between 1999 and 2004. Mental Developmental Index (MDI) and Psychomotor Developmental Index were assessed using Bayley Scales of Infant Development and correlated with intraoperative and perioperative variables. Results are reported as mean +/- standard deviation.

RESULTS

Average age at stage 1 operation and at bidirectional Glenn was 7 +/- 8 days and 6.0 +/- 2 months, respectively. The MDI was in the low average range (87.7 +/- 13.2). The Psychomotor Developmental Index was in the mildly delayed range (75.2 +/- 14.5). Regional low-flow perfusion was used in 31% (9 of 29 patients), with an average circulatory arrest time of 23.5 +/- 13.4 minutes. Deep hypothermia and circulatory arrest was used as the primary operative strategy in 69% of patients (20 of 29 patients), with an average circulatory arrest time of 44.3 +/- 15.3 minutes (p = 0.003). No differences in MDI or Psychomotor Developmental Index scores were observed between the regional low-flow perfusion and non-regional low-flow perfusion groups (MDI, 88.0 +/- 12.1 versus 87.6 +/- 14.0; p = 0.93, respectively; Psychomotor Developmental Index, 75.5 +/- 15.1 versus 75.0 +/- 14.6; p = 0.93, respectively). Lowest operative temperature (<16 degrees C) and birth order (<2 versus >3) significantly related to MDI (89.6 versus 72.8; p = 0.047).

CONCLUSIONS

At 1 year of age, neurodevelopmental outcomes of patients undergoing stage 1 using regional low-flow perfusion were similar to outcomes observed in children exposed to circulatory arrest. The association of birth order and MDI suggests that early intervention may benefit these patients.

Muscle engraftment of myogenic progenitor cells following intraarterial transplantation

Cell-based therapy continues to be a promising avenue for the treatment of Duchenne muscular dystrophy (DMD), an X-linked skeletal muscle-wasting disease. Recently, we demonstrated that freshly isolated myogenic progenitors contained within the adult skeletal muscle side population (SP) can engraft into dystrophic fibers of nonirradiated mdx(5cv) mice after intravenous transplantation. Engraftment rates, however, have not been therapeutically significant, achieving at most 1% of skeletal muscle myofibers expressing protein from donor-derived nuclei. To enhance the engraftment of transplanted myogenic progenitors, an intraarterial delivery method was adapted from a previously described procedure. Cultured, lentivirus-transduced skeletal muscle SP cells, derived from mdx(5cv) mice, were transplanted into the femoral artery of noninjured mdx(5cv) mice. Based on the expression of microdystrophin or green fluorescent protein (GFP) transgenes in host muscle, sections of the recipient muscles exhibited 5%-8% of skeletal muscle fibers expressing donor-derived transgenes. Further, donor muscle SP cells, which did not express any myogenic markers prior to transplant, expressed the satellite cell transcription factor, Pax7, and the muscle-specific intermediate filament, desmin, after extravasation into host muscle. The expression of these muscle-specific markers indicates that progenitors within the side population can differentiate along the myogenic lineage after intraarterial transplantation and extravasation into host muscle. Given that femoral artery catheterization is a common, safe clinical procedure and that the transplantation of cultured adult muscle progenitor cells has proven to be safe in mice, our data may represent a step toward the improvement of cell-based therapies for DMD and other myogenic disorders.

Report of the National Heart, Lung, and Blood Institute Working Group on Research in Adult Congenital Heart Disease

The Working Group on research in adult congenital heart disease (ACHD) was convened in September 2004 under the sponsorship of National Heart, Lung, and Blood Institute (NHLBI) and the Office of Rare Diseases, National Institutes of Health, Department of Health and Human Services, to make recommendations on research needs. The purpose of the Working Group was to advise the NHLBI on the current state of the science in ACHD and barriers to optimal clinical care, and to make specific recommendations for overcoming those barriers. The members of the Working Group were chosen to provide expert input on a broad range of research issues from both scientific and lay perspectives. The Working Group reviewed data on the epidemiology of ACHD, long-term outcomes of complex cardiovascular malformations, issues in assessing morphology and function with current imaging techniques, surgical and catheter-based interventions, management of related conditions including pregnancy and arrhythmias, quality of life, and informatics. After research and training barriers were discussed, the Working Group recommended outreach and educational programs for adults with congenital heart disease, a network of specialized adult congenital heart disease regional centers, technology development to support advances in imaging and modeling of abnormal structure and function, and a consensus on appropriate training for physicians to provide care for adults with congenital heart disease.

Cardioprotection afforded by ischemic preconditioning interferes with chronic beta-blocker treatment

OBJECTIVES

The efficacy of ischemic preconditioning of the heart has remained controversial. We investigated whether chronic treatment with beta-blockers affects the ischemic preconditioning in the isolated rat heart model.

DESIGN

Wistar rats were treated with propranolol (50 mg/kg/day, p.o.) (PRL), with nipradilol (10 mg/kg/day, p.o.) (NPL), or with vehicle, for 4 weeks. Isolated rat hearts were divided into global ischemia hearts (GI, PRL and NPL, each n=6) and ischemic preconditioned hearts (IP, PRL+IP and NPL+IP, each n=6).

RESULTS

Significant differences in left ventricular pressure were observed between the PRL and PRL+IP, and between the NPL and NPL+IP groups. In the NPL group, significant amelioration and preservation of left ventricular peak pressure, coronary flow, reduction of infarct size, and NOx preservation were observed. Lipid peroxidation in the NPL group was significantly reduced before and after global ischemia compared to the GI group.

CONCLUSIONS

The effect of ischemic preconditioning was abolished in the hearts of rats following oral treatment of propranolol or nipradilol. However, the administration of nipradilol protected the ischemic and reperfused myocardium, partly due to the prevention of lipid peroxide formation.

Long-Term Predictors of Aortic Root Dilation and Aortic Regurgitation After Arterial Switch Operation

BACKGROUND

Neo-aortic root dilation (ARD) and neo-aortic regurgitation (AR) may be progressive after arterial switch operation (ASO) for d-loop transposition of the great arteries (dTGA). We sought to identify predictors of ARD and AR after ASO.

METHODS AND RESULTS

335 patients were identified who underwent ASO for dTGA with intact ventricular septum or ventricular septal defect (VSD), including double-outlet right ventricle (DORV), before 2001 with at least 1 postoperative echocardiogram at our institution, at least 1 year after ASO, and no previous atrial switch procedure (median follow-up of 5.0 years). Probability of freedom from ARD was 97%, 92%, 82%, and 51%, from at least moderate AR was 98%, 97%, 96%, and 93%, and from neo-aortic valve or root surgery was 100%, 100%, 99%, and 95%, at 1, 2, 5, and 10 years, respectively. For patients in whom ARD developed, progressive dilation was not observed during late follow-up. By Kaplan-Meier method, independent predictors of ARD, with neo-aortic root z-score of > or =3.0, were previous pulmonary artery band (PAB) (P=0.002, hazard ratio [HR]=2.4) and later time period when ASO was performed (P<0.002, HR=19.0). Risk factor for at least moderate AR was age > or =1 year at ASO (P=0.002, HR=5.8), which was closely related to VSD repair at ASO (P<0.001) and previous PAB.

CONCLUSIONS

Significant ARD and AR continue to develop over time after ASO, but ARD does not tend to be progressive during late follow-up. Previous PAB was a significant risk factor for ARD. Older age at time of ASO, presence of VSD, and previous PAB were risk factors for AR.

Left pulmonary artery sling: diagnosis and delineation of associated tracheobronchial anomalies with MR

BACKGROUND

The left pulmonary artery sling anomaly (SLPA) has generated controversy about its diagnosis, imaging and management particularly with regard to associated tracheobronchial anomalies. Objective. To evaluate the role of MR imaging in defining airway and vascular relationships in SLPA.

MATERIALS AND METHODS

Retrospective review of the imaging and clinical records of three children with SLPA who underwent MRI including three dimensional image reconstruction. MR was compared and correlated with other imaging methods: plain chest radiographs (3); bronchoscopy (3); barium esophagram (1); echocardiography (2); cineangiography (2).

RESULTS

MRI was vastly superior to other methods for clearly depicting airway and vascular anatomy and interrelationships. Good quality imaging and safe sedation was easily achieved in young infants. MR also provided accurate noninvasive evaluation of the reconstructed pulmonary artery and airway postoperatively.

CONCLUSION

MR is capable of differentiating the two subtypes of SLPA. Specific delineation of vascular and airway anatomy and spatial relationships is essential for surgical management: reimplantation of LPA in type I and both LPA reimplantation and airway reconstruction in type II because of associated long segment airway stenosis.