Increased mortality, morbidities, and costs after heart transplantation in heterotaxy syndrome and other complex situs arrangements

Orthotopic heart transplantation in patient with situs inversus and pectus excavatum: a case report

BACKGROUND

Heart transplantation in patients with situs inversus is challenging, especially in terms of reconstruction of the systemic venous return. Several rerouting techniques have been presented but are associated with vulnerability to external compression, which might cause hemodynamic instability, especially in the presence of chest deformity. In this study, we report a rare case of successful heart transplantation in the presence of situs inversus and pectus excavatum.

CASE PRESENTATION

A 55-year-old man, with a history of surgeries for corrected transposition of the great arteries with ventricular septal defect, was registered for heart transplantation owing to progression of heart failure. Subsequently, he had undergone a left ventricular assist device implantation; 14 years after registration, he underwent transplantation of the heart with normal anatomy. The inferior vena cava was reconstructed by anastomosing the left atria with a counterclockwise rotation of the donor heart and by lengthening the recipient inferior vena cava with a conduit made of the residual right atrial tissue. The superior vena cava was reconstructed using a donor innominate vein harvested with sufficient length. After successful weaning from cardiopulmonary bypass, the chest could not be closed because the heart was compressed owing to chest deformity, resulting in hemodynamic instability. Therefore, to exclude the left lung, a left pericardial screen was created using a bovine pericardium, allowing the chest to be closed with acceptable hemodynamics. The patient suffered postoperatively from a higher venous pressure, suggesting an obstruction of venous return early after surgery. The obstruction gradually resolved, and the patient was transferred for rehabilitation.

CONCLUSIONS

Heart transplantation in the presence of situs inversus is challenging; moreover, the presence of pectus excavatum further complicates the procedure. The paradoxically larger left lung and chest deformity compressed and impaired reconstructed systemic venous return. Although intrathoracic exclusion of the left lung was effective, an intraoperative or early postoperative thoracoplasty for pectus excavatum was also a viable option. Patient-specific management is mandatory, depending on the anatomy.

Contemporary Outcomes of Heart Transplantation in Children with Heterotaxy Syndrome: Sub-Optimal Pre-Transplant Optimization Translates into Early Post-Transplant Mortality

Patients with heterotaxy syndrome and congenital heart disease (CHD) experience inferior cardiac surgical outcomes. Heart transplantation outcomes are understudied, however, particularly compared to non-CHD patients. Data from UNOS and PHIS were used to identify 4803 children (< 18 years) undergoing first-time heart transplant between 2003 and 2022 with diagnoses of heterotaxy (n = 278), other-CHD (n = 2236), and non-CHD cardiomyopathy (n = 2289). Heterotaxy patients were older (median 5 yr) and heavier (median 17 kg) at transplant than other-CHD (median 2 yr and 12 kg), and younger and lighter than cardiomyopathy (median 7 yr and 24 kg) (all p < 0.001). UNOS status 1A/1 at listing was not different between groups (65-67%; p = 0.683). At transplant, heterotaxy and other-CHD patients had similar rates of renal dysfunction (12 and 17%), inotropes (10% and 11%), and ventilator-dependence (19 and 18%). Compared to cardiomyopathy, heterotaxy patients had comparable renal dysfunction (9%, p = 0.058) and inotropes (46%, p = 0.097) but more hepatic dysfunction (17%, p < 0.001) and ventilator-dependence (12%, p = 0.003). Rates of ventricular assist device (VAD) were: heterotaxy-10%, other-CHD-11% (p = 0.839 vs. heterotaxy), cardiomyopathy-37% (p < 0.001 vs. heterotaxy). The 1-year incidence of acute rejection post-transplant was comparable between heterotaxy and others (p > 0.05). While overall post-transplant survival was significantly worse for heterotaxy than others (p < 0.05 vs. both), conditional 1-year survival was comparable (p > 0.3 vs. both). Children with heterotaxy syndrome experience inferior post-heart transplant survival, although early mortality appears to influence this trend, with 1-year survivors having equivalent outcomes. Given similar pre-transplant clinical status to others, heterotaxy patients are potentially under risk-stratified. Increased VAD utilization and pre-transplant end-organ function optimization may portend improved outcomes.

Interventions on residual lesions in patients with heterotaxy syndrome following orthotropic heart transplantation: A single-center experience

BACKGROUND

Heterotaxy syndrome (HS) is a defect in lateralization which often results in complex intra and extracardiac abnormalities. Orthotropic heart transplantation (OHT) in HS involves intricate and individualized modifications to surgical technique. Post-OHT outcomes are worse in patients with HS, however, the impact of post-OHT residual lesions has not yet been characterized.

METHODS

Patients with HS who underwent OHT at Ann & Robert H. Lurie Children's Hospital of Chicago between January 2012 and June 2023 were identified. Patients were excluded if follow-up data was not available due to follow up at a different institution of early mortality. Pre-OHT clinical data, surgical data, and post-OHT surgical and catheterization data were collected.

RESULTS

Two early mortalities were excluded from analysis, leaving 15 patients in the study cohort. Median age at OHT was 3.7 years (range: 0.7-15.4). Nine out of 15 patients were diagnosed with residual lesions requiring intervention at a median of 188 days post transplantation. All interventions on residual lesions occurred via catheterization. Overall mortality rate was 27% (4/15) with all deaths occurring in patients with residual lesions (4/9 patients, 44%). 83% (10/12) of lesions were diagnosed via catheterization, and 83% (10/12) of lesions of occurred in the first year after transplant.

CONCLUSIONS

Patients with HS are at high risk for residual lesions after OHT, which may contribute to increased mortality. Comprehensive invasive diagnostics were required to diagnose residual lesions, which were all addressed percutaneously.

Predictive factors contributing to prolonged recovery in patients after Fontan operation

Background

Prolonged recovery is a severe issue in patients after Fontan operation. However, predictive factors related to this issue are not adequately evaluated. The present study aimed to investigate potential predictive factors which can predict Fontan postoperative recovery.

Methods

We retrospectively reviewed the perioperative medical records of patients with Fontan surgery between January 2015 and December 2018, and divided patients with > 75%ile cardiac intensive care unit stay into prolonged recovery group. The others were assigned to standard recovery group. Patients that died or underwent a Fontan takedown were excluded. Statistical analysis was performed to compare data difference of the two groups.

Results

282/307 cases fulfilled the inclusion criteria. Seventy patients were considered in prolonged recovery and 212 patients were defined as standard recovery. Pre- and intra-operative data showed a higher incidence of heterotaxy syndrome, longer cardiopulmonary bypass and aortic cross-clamp time in the prolonged recovery group. Postoperative information analysis displayed that ventilation time, oxygen index after extubation, hemodynamic data, inotropic score (IS), drainage volume, volume resuscitation, pulmonary hypertension (PH) treatment, and surgical reintervention were significantly different between the two groups. Higher IS postoperatively, and PH treatment and higher fluid resuscitation within two days were independent predictive factors for prolonged recovery in our multivariate model. C-statistic model showed a high predictive ability in prolonged recovery by using the three factors.

Conclusions

Ventilation time, higher IS in postoperative day, and PH treatment and higher fluid resuscitation within two days were independent risk factors and have a high predictability for Fontan prolonged recovery.

Pediatric heart transplantation: The past, the present, and the future

Heart transplantation (HTx) has a storied past, with origins dating back to the early twentieth century and the first pediatric orthotopic heart transplant performed in 1967 on a neonate with Ebstein abnormality. Today, approximately 500 pediatric HTx are performed annually, with survival times now measured in decades rather than days or weeks. In large part, advances in immunosuppression, critical care, dedicated transplant teams and mechanical circulatory support have paved the way for improvements in waitlist mortality and post-transplant survival, with future directions including the development of intracorporeal ventricular assist devices (VADs) for small children, expanding/standardizing donor criteria, and xenotransplantation.

Post-operative Morbidity and Mortality After Fontan Procedure in Patients with Heterotaxy and Other Situs Anomalies

Heterotaxy is a complex, multisystem disorder associated with single ventricle heart disease and decreased survival. Ciliary dysfunction is common in heterotaxy and other situs abnormalities (H/SA) and may increase post-operative complications. We hypothesized that patients with H/SA have increased respiratory and renal morbidities and increased in-hospital mortality after Fontan procedure. We queried the Pediatric Health Information System database for hospitalizations with ICD-9/10 codes for Fontan procedure in patients aged 1 through 11 years from 2004 to 2019. H/SA was identified by codes for dextrocardia, situs inversus, asplenia/polysplenia, or atrial isomerism and compared to non-H/SA controls. Outcomes were in-hospital mortality or heart transplantation, ECMO, hemodialysis, length of stay (LOS), and mechanical ventilation or vasoactive medication use ≥ 4 days. We adjusted estimates with multivariable logistic regression. Of 7897 patients at 50 centers, 1366 (17%) met criteria for H/SA. H/SA had worse outcomes for all study measures: death/transplantation (1.9 vs 1.1%, OR 1.74 (95% CI 1.01-3.03); p = 0.047), ECMO (3.7 vs 2.3%, OR 1.74 (1.28-2.35); p < 0.001), hemodialysis (2.1 vs 1.2%, OR 1.66 (1.06-2.59); p = 0.026), prolonged mechanical ventilation (13.2% vs 7.6%, OR 1.85 (1.53-2.25); p < 0.001) and vasoactive medication use (29.4 vs 19.7%, OR 1.65 (1.43-1.90), and longer LOS (11 (8-17) vs 9 (7-14) days; p < 0.001). H/SA is associated with increased cardiovascular, renal, and respiratory morbidity, as well as in-hospital mortality after Fontan procedure. Attention to renal and respiratory needs may improve outcomes in this difficult population. The relationship between ciliary dysfunction and lung and renal morbidity should be explored further.

Surgical management of hearts with isomeric atrial appendages

BACKGROUND AND AIM

On the basis of previously published accounts, coupled with our own experience, we have assessed the surgical approaches to patients with isomeric atrial appendages.

METHODS

We reviewed pertinent published studies on surgical treatment of individuals with isomeric atrial appendages, with the pertinent surgical details provided by most of the manuscripts.

RESULTS

Half of patients with right isomerism, and two-thirds of those with left isomerism have bilateral superior caval veins. Azygos extension of the inferior caval vein is reported in three-quarters of those with left isomerism. The coronary sinus is universally absent in right isomerism, along with totally anomalous pulmonary venous connection, and is absent in two-fifths of those with left isomerism. Univentricular atrioventricular connections are expected in up to three-quarters of those with right isomerism. Atrioventricular septal defect is reported in up to four-fifths, more frequently in right isomerism, with such patients typically having discordant ventriculoatrial connections or double outlet right ventricle. Reported mortalities extend to 85% for those with right, and 50% for those with left isomerism. In right isomerism, mortality is up to 54% for systemic-to-pulmonary arterial shunting, up to 75% for univentricular repair, and up to 95% for repair of totally anomalous pulmonary venous connection itself. No more than one-quarter had undergone Fontan completion, with reported mortalities of 21%.

CONCLUSION

Early surgical results are satisfactory in patients with left isomerism, but disappointing for those with right. Recent advances in cardiac and liver transplantation may offer improved survival.

Improved heart transplant survival for children with congenital heart disease and heterotaxy syndrome in the current era: An analysis from the pediatric heart transplant society

BACKGROUND

Challenges exist with heterotaxy due to the complexity of heart disease, abnormal venous connections, and infection risks. This study aims to understand heart transplant outcomes for children with heterotaxy.

METHODS

All children with congenital heart disease listed for transplant from 1993 to 2018 were included. Those with and without heterotaxy were compared. Waitlist outcomes and survival post-listing and transplant were analyzed. Post-transplant risk factors were identified using multiphase parametric hazard modeling.

RESULTS

There were 4814 children listed, of whom 196 (4%) had heterotaxy. Heterotaxy candidates were older (5.8 ± 5.7 vs 4.2 ± 5.5 years, p < 0.01), listed at a lower urgency status (29.8% vs 18.4%, p < 0.01), more commonly single ventricle physiology (71.3% vs 59.2%, p < 0.01), and less often supported by mechanical ventilation (22% vs 29.1%, p < 0.05) or extracorporeal membrane oxygenation (3.6% vs 7.5%, p < 0.05). There were no differences in waitlist outcomes of transplant, death, or removal. Overall, post-transplant survival was worse for children with heterotaxy: one-year survival 77.2% vs 85.1%, with and without heterotaxy, respectively. Heterotaxy was an independent predictor for early mortality in the earliest era (1993-2004), HR 2.09, CI 1.16-3.75, p = 0.014. When stratified by era, survival improved with time. Heterotaxy patients had a lower freedom from infection and from severe rejection, but no difference in vasculopathy or malignancy.

CONCLUSIONS

Mortality risk associated with heterotaxy is mitigated in the recent transplant era. Early referral may improve waitlist outcomes for heterotaxy patients who otherwise have a lower status at listing. Lower freedom from both infection and severe rejection after transplant in heterotaxy highlights the challenges of balancing immune suppression.

Predicting Cardiac Anatomy, Physiology, and Surgical Management Based on Fetal Echocardiography in Heterotaxy Syndrome

OBJECTIVE

 Heterotaxy syndrome (HS) is often associated with complex congenital heart disease (CHD). While fetal echocardiography (FE) permits accurate prenatal identification of most CHD, the high level of disease complexity in HS may pose challenges in predicting postnatal findings and outcomes. This study aimed to define the accuracy of FE in predicting postnatal anatomy, physiology, and surgical management of CHD in the setting of HS.

STUDY DESIGN

 Retrospective single-center cohort study including all patients with a prenatal diagnosis of HS from 2003 to 2018. Anatomic diagnoses from FE reports were compared with postnatal echocardiogram, catheterization, and operative reports. Prenatal predictions were compared with postnatal outcomes with a focus on ductal dependence, time to first intervention (immediate, neonatal period, 1-6 months, or older than 6 months), and surgical approach (single or biventricular).

RESULTS

 There were 102 pregnancies with fetal HS resulting in 21 terminations, 5 fetal losses, and 76 live births. Of the live births, 55 had significant CHD and available postnatal data for review. Among this group, survival to 1 year was 62% and was no different comparing single versus biventricular surgical approach. FE diagnostic accuracy varied by anatomic feature and was the lowest for diagnosis of venous anatomy. Determination of postnatal care was most accurate for predicting single versus biventricular surgical approach (91%), followed by ductal dependence (75%). Accuracy for predicting time to first intervention was the lowest at 69%. The most common reason for an incorrect prediction was difficulty in assessing the severity of pulmonary stenosis.

CONCLUSION

 FE permits accurate predictions regarding surgical approach. Characterizing systemic and pulmonary veins is challenging, as is predicting ductal dependence and time to first intervention. These data suggest that despite the high diagnostic accuracy of CHD in HS, a circumspect approach may be reasonable with regard to predicting some anatomic details and postnatal management decisions.

KEY POINTS

· In HS, FE was most accurate for intracardiac anatomy.. · Diagnostic accuracy of venous anatomy was less reliable.. · Predicting surgical approach (single ventricle vs. biventricular) was highly accurate.. · Predicting ductal dependence and time-to-intervention were more challenging in some instances..

Identification of novel candidate genes in heterotaxy syndrome patients with congenital heart diseases by whole exome sequencing

Heterotaxy syndrome (HS) involves dysfunction of multiple systems resulting from abnormal left-right (LR) body patterning. Most HS patients present with complex congenital heart diseases (CHD), the disability and mortality of HS patients are extremely high. HS has great heterogeneity in phenotypes and genotypes, which have rendered gene discovery challenging. The aim of this study was to identify novel genes that underlie pathogenesis of HS patients with CHD. Whole exome sequencing was performed in 25 unrelated HS cases and 100 healthy controls; 19 nonsynonymous variants in 6 novel candidate genes (FLNA, ITGA1, PCNT, KIF7, GLI1, KMT2D) were identified. The functions of candidate genes were further analyzed in zebrafish model by CRISPR/Cas9 technique. Genome-editing was successfully introduced into the gene loci of flna, kmt2d and kif7, but the phenotypes were heterogenous. Disruption of each gene disturbed normal cardiac looping while kif7 knockout had a more prominent effect on liver budding and pitx2 expression. Our results revealed three potential HS pathogenic genes with probably different molecular mechanisms.

Neonatal Assessment of Infants with Heterotaxy

Heterotaxy is a generalized term for patients who have an abnormality of laterality that cannot be described as situs inversus. Infants with heterotaxy can have significant anatomic and medical complexity and require personalized, specialized care, including comprehensive anatomic assessment. Common and rare anatomic findings are reviewed by system to help guide a thorough phenotypic evaluation. General care guidelines and considerations unique to this patient population are included. Future directions for this unique patient population, particularly in light of improved neonatal survival, are discussed.

Expanding analytic possibilities in pediatric solid organ transplantation through linkage of administrative and clinical registry databases

Database linkage is a common strategy to expand analytic possibilities. Our group recently completed a linkage between the SRTR and PHIS databases for pediatric heart transplant recipients. The aim of this project was to expand the linkage between SRTR and PHIS to include liver, kidney, lung, heart-lung, and small bowel transplants. All patients (<21 years) who underwent liver, kidney, lung, heart-lung, or small bowel transplant were identified from the PHIS database using APR-DRG codes (2002-2018). Linkage was performed in a stepwise approach using indirect identifiers. Hospital costs were estimated based on hospital charges and cost-to-charge ratios, inflated to 2018 dollars and described by transplant type. A total of 14 061 patients overlapped between databases. Of these, 13 388 (95.2%) were uniquely linked. Linkage success ranged from 92.6% to 97.8% by organ system. A total of 12 940 (92%) patients had complete cost data. Hospitalization costs were greatest for patients undergoing small bowel transplantation with a median cost of $734 454 (IQR $336 174 - $1 504 167), followed by heart $565 386 (IQR $352 813 - $999 216), heart-lung $471 573 (IQR $328 523 - 992 438), lung $303 536 (IQR $215 383 - $612 749), liver $200 448 (IQR $130 880 - $357 897), and kidney transplant $94 796 (IQR $73 157 -$131 040). We report a robust linkage between the SRTR and PHIS databases, providing an invaluable tool to assess resource utilization in solid organ transplant recipients. Our analysis provides contemporary cost data for pediatric solid organ transplantation from the largest US sample reported to date. It also provides a platform for expanded analyses in the pediatric transplant population.