Post-transplant seizures in infants with hypoplastic left heart syndrome

Perioperative electroencephalography in cardiac surgery with hypothermic circulatory arrest: a narrative review

OBJECTIVES

Cardiac surgery with hypothermic circulatory arrest (HCA) is associated with neurological morbidity of variable severity and electroencephalography (EEG) is a sensitive proxy measure of brain injury. We conducted a narrative review of the literature to evaluate the role of perioperative EEG monitoring in cardiac surgery involving HCA.

METHODS

Medline, Embase, Central and LILACS databases were searched to identify studies utilizing perioperative EEG during surgery with HCA in all age groups, published since 1985 in any language. We aimed to compare EEG use with no use but due to the lack of comparative studies, we performed a narrative review of its utility. Two or more reviewers independently screened studies for eligibility and extracted data.

RESULTS

Fourty single-centre studies with a total of 3287 patients undergoing surgery were identified. Most were observational cohort studies (34, 85%) with only 1 directly comparing EEG use with no use. EEG continuity (18, 45%), seizures (15, 38%) and electrocerebral inactivity prior to circulatory arrest (15, 38%) were used to detect, monitor, prevent and prognose neurological injury. Neurological dysfunction was reported in almost all studies and occurred in 0-21% of patients. However, the heterogeneity of reported clinical and EEG outcome measures prevented meta-analysis.

CONCLUSIONS

EEG is used to detect cortical ischaemia and seizures and predict neurological abnormalities and may guide intraoperative cerebral protection. However, there is a lack of comparative data demonstrating the benefit of perioperative EEG monitoring. Use of a standardized methodology for performing EEG and reporting outcome metrics would facilitate the conduct of high-quality clinical trials.

Incidence, risk factors, and outcomes in electroencephalographic seizures after mechanical circulatory support: A systematic review and meta-analysis

Purpose

To estimate the overall incidence, risk factors, and clinical outcomes of electroencephalographic (EEG) seizures for adults and children after mechanical circulatory support (MCS).

Method and measurements

This systematic review and meta-analysis were carried out in accordance with the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidance document. MEDLINE EMBASE and CENTRAL were investigated for relevant studies. The related information was retrieved by two independent reviewers and all analyses were conducted by STATA (version 16.0; Stata Corporation, College Station, TX, United States).

Result

Sixty studies including 36,191 adult and 55,475 pediatric patients with MCS were enrolled for evaluation. The study showed that the overall incidence of EEG seizures in adults was 2% (95%CI: 1–3%), in which 1% (95%CI: 1–2%) after cardiopulmonary bypass (CPB), and 3% (95%CI: 1–6%) after extracorporeal membrane oxygenation (ECMO). For pediatrics patients, the incidence of EEG seizures was 12% (95%CI: 11–14%), among which 12% (9–15%) after CPB and 13% (11–15%) after ECMO. The major risk factors of EEG seizures after MCS in adults were redo surgery (coefficient = 0.0436, p = 0.044), and COPD (coefficient = 0.0749, p = 0.069). In addition, the gestational week of CPB (coefficient = 0.0544, p = 0.080) and respiratory failure of ECMO (coefficient = –0.262, p = 0.019) were also indicated to be associated with EEG seizures in pediatrics.

Conclusion

EEG seizures after MCS were more common in pediatrics than in adults. In addition, the incidence of EEG seizure after ECMO was higher than CPB both in adults and children. It is expected that appropriate measures should be taken to control modifiable risk factors, thus improving the prognosis and increasing the long-term survival rate of MCS patients.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero], identifier [CRD42021287288].

Associations between executive functioning, personality, and posttraumatic stress symptoms in adolescent solid organ transplant recipients

BACKGROUND

Pediatric solid organ transplant recipients are susceptible to posttraumatic stress symptoms (PTSS), given the presence of a life-threatening chronic medical condition and potential for complications. However, little is known about what individual characteristics are associated with an increased risk for PTSS among youth who received an organ transplant. The aim of the current study was to evaluate PTSS and its associations with executive functioning (EF) and personality (i.e., neuroticism and conscientiousness) among adolescents with solid organ transplants.

METHODS

Fifty-three adolescents (M_age  = 16.40, SD = 1.60) with a kidney, heart, or liver transplant completed self-report measures of PTSS and personality, whereas caregivers completed a caregiver-proxy report of adolescent EF.

RESULTS

Twenty-two percent of adolescent transplant recipients reported clinically significant levels of PTSS. Higher EF difficulties and neuroticism levels, and lower conscientiousness levels were significantly associated with higher PTSS (rs -.34 to .64). Simple slope analyses revealed that adolescents with both high EF impairment and high levels of neuroticism demonstrated the highest PTSS (t = 3.47; p < .001).

CONCLUSIONS

Most adolescent transplant recipients in the present study did not report clinically significant levels of PTSS; however, those with high neuroticism and greater EF difficulties may be particularly vulnerable to PTSS following organ transplantation. Following transplantation, medical providers should assess for PTSS and risk factors for developing PTSS. Identification of those at risk for PTSS is critical, given the strong associations between PTSS and certain medical outcomes (e.g., medication nonadherence) among these youth.

Deep Hypothermic Circulatory Arrest in the Pediatric Population Undergoing Cardiac Surgery With Electroencephalography Monitoring: A Systematic Review and Meta-Analysis

OBJECTIVE

Cardiac surgery for repair of congenital heart defects poses unique hazards to the developing brain. Deep hypothermic circulatory arrest (DHCA) is a simple and effective method for facilitating a bloodless surgical field during congenital heart defect repair. There are, however, some concerns that prolonged DHCA increases the risk of nervous system injury. The electroencephalogram (EEG) is used in adult and, to a lesser extent, pediatric cardiac procedures as a neuromonitoring method. The present study was performed to assess outcomes following DHCA with EEG monitoring in the pediatric population.

DESIGN

In this systematic review and meta-analysis, the PubMed, Cochrane Central Register of Controlled Trials, Scopus, Institute of Science Index, and Embase databases were searched from inception for relevant articles. A fixed- or random-effects model, as appropriate, was used.

SETTING

Surgical setting.

PARTICIPANTS

Pediatric population (≤18 y old).

INTERVENTIONS

DHCA (18°C) with EEG monitoring.

MEASUREMENTS AND MAIN RESULTS

Nineteen articles with 1,267 pediatric patients ≤18 years were included. The event rate of clinical and EEG seizures among patients who underwent DHCA was 12.9% and 14.9%, respectively. Mortality was found to have a 6.3% prevalence. A longer duration of DHCA was associated with a higher risk of EEG seizure and neurologic abnormalities. In addition, seizures were associated with increased neurologic abnormalities and neurodevelopmental delay.

CONCLUSIONS

EEG and neurologic abnormalities were common after DHCA. A longer duration of DHCA was found to lead to more EEG seizure and neurologic abnormalities. Moreover, EEG seizures were more common than clinical seizures. Seizures were found to be associated with increased neurologic abnormalities and neurodevelopmental delay.

Executive Functioning in Pediatric Solid Organ Transplant Recipients: A Meta-analytic Review

BACKGROUND

Examining executive functioning (EF) posttransplant has become increasingly prevalent, as EF deficits are associated with poor disease-related outcomes and psychosocial functioning. The purpose of the current meta-analysis was to compare overall and domain-specific EF between healthy youth and those with a kidney, heart, or liver transplant, and identify moderating variables related to EF differences between these 2 groups.

METHODS

A literature search of PsycINFO, Pubmed, and Medline was conducted for eligible articles published until January 2019. Twenty studies met eligibility criteria and were included in the present meta-analysis.

RESULTS

Results from the random-effects model indicated a significant standardized mean difference in overall EF skills with transplant recipients demonstrating worse EF (g = 0.40; 95% confidence interval [CI], 0.29-0.50) than healthy youth. Specifically, transplanted youth had worse working memory (g = 0.33; 95% CI, 0.01-0.66), processing speed (g = 0.41; 95% CI, 0.19-0.62), attentional control (g = 0.53; 95% CI, 0.33-0.73), and metacognitive skills (g = 0.36; 95% CI, 0.18-0.54). Assessment type and time since transplantation were not significant moderators.

CONCLUSIONS

Pediatric solid organ transplant recipients demonstrate worse overall EF skills and deficits in working memory, processing speed, attentional control, and metacognitive skills. Many children who have undergone solid organ transplantation will require additional support in medical and academic settings because of deficits in various EF domains.

Early stroke post-heart transplant is associated with decreased survival in children

BACKGROUND

Major neurologic events (MNEs) after heart transplantation (HTx) and their effect on survival have not been well described in children. In this study we aimed to characterize early MNEs (stroke, isolated seizures not from stroke and posterior reversible leukoencephalopathy [PRES] within 1 year after primary pediatric HTx) and evaluate their impact on 1-year post-HTx survival. We hypothesized that early an MNE after HTx is associated with decreased 1-year patient survival.

METHODS

We performed a pediatric, single-center, retrospective analysis of 345 consecutive patients aged 0 to 22 years who underwent primary HTx during the period from November 1, 1994 to October 31, 2015. Characteristics were compared between patients with and without early MNEs.

RESULTS

Nineteen percent (65 of 345) of patients had an MNE within 1 year after HTx (median 9 days, interquartile range [IQR] 4 to 23 days). Freedom from early MNE was 97%, 85% and 80% at 1, 6 and 12 months, respectively. Of the total 65 events, stroke comprised 55.4% (n = 36), isolated seizure 29.2% (n = 19) and PRES 15.4% (n = 10). With multiple logistic regression, previous neurologic disease, infection requiring intravenous antibiotic therapy and post-operative drug-treated hypertension were found to be significant risk factors for early MNEs. Stroke (hazard ratio 4.1, IQR 2.3 to 7.6, p < 0.0001), but not seizures and PRES, was associated with decreased 1-year patient survival.

CONCLUSIONS

Major neurologic events are common after pediatric HTx and usually occur within the first few weeks. Early stroke was associated with decreased 1-year survival. Potentially modifiable factors, including prior neurologic event, drug-treated hypertension and infection, were associated with increased risk of developing early MNEs.

Neurologic aspects of heart transplantation

Cardiac transplantation remains the best treatment option for patients with end-stage, NYHA class IV heart failure who have failed conventional therapy. However, transplant rates have remained static largely due to limited organ donor supplies. Therefore, appropriate allocation of this precious resource is critical to maximize benefit, both at a patient level and at a societal level. Neurologic diseases, such as cerebrovascular disease and peripheral neuropathy, are prevalent in this patient population, as the major risk factors for heart disease place patients at risk for neurologic disease as well. Examples include hypertension, smoking, hypercholesterolemia, obesity, and diabetes. Pretransplant neurologic evaluation is very important to identify conditions that may limit survival after cardiac transplantation. In general, systemic diseases exacerbated by immunosuppression, conditions limiting ability to rehabilitate, and dementias are considered contraindications. Post-transplant neurologic complications are divided into central versus peripheral, and early versus late. The most common early complication is ischemic stroke. Other serious complications include hemorrhagic stroke, encephalopathy, and critical illness neuropathy. Over the long term, post-transplant immunosuppressive regimens are considered "a double edged sword." Although immunosuppressive medications are critical to preventing rejection and allograft dysfunction, they do have significant risk of morbidity and mortality associated with them, including neurologic side-effects. These include: (1) drug toxicities, such as lowering of seizure thresholds; (2) encephalopathy, such as posterior reversible encephalopathy syndrome (PRES); (3) infections; (4) malignancies, such as post-transplant lymphoproliferative disorder (PTLD). Many of the same considerations discussed in adult heart transplant recipients apply to pediatric heart transplant recipients as well. In children, seizures are the most common neurologic complication, although other neurologic complication rates are comparable.

Incidence and risk factors for seizures after heart transplantation

Neurological complications can occur after heart transplantation and present with seizures. We examined the incidence of seizures from a population of adult patients who had received heart transplants over a period of 3 years. Brain MRI and clinical data were analysed to identify the risk factors for the seizures. Eight of the 166 post-transplant patients presented seizures (4.8%). The first seizures occurred with a mean of 30 days after the transplantation. For seven patients, the mean delay was 8 days, and for one, it was longer, 172 days. The analysis of brain MRI showed two main epileptogenic factors in the early post-transplant seizures: posterior reversible encephalopathy syndrome (PRES) due to cyclosporine treatment (n = 4) and cortical ischemic stroke (n = 5). In two patients, we identified multiple epileptogenic factors, including notably the association of PRES and cortical stroke. Since treatment of seizures in patients in the intensive care unit (ICU) after heart transplantation depends on identifying and correcting the causes, FLAIR and diffusion MRI sequences are needed, even if the patients have a previous history of epilepsy. Seizures were easy to control. In patients with PRES, imaging and clinical abnormalities improved when cyclosporine was replaced by another immunosuppressive treatment. Death of three patients was not related to seizures, but to infectious or malignant complications of immunosuppressive treatments (n = 2) or to post-stroke neurological deficit (n = 1). Mortality was similar among patients presenting seizures and those who did not.

Developmental outcomes after pediatric heart transplantation

BACKGROUND

Pediatric heart transplantation has now been successfully performed for more than 20 years. As survival rates have improved, more attention is now focused on long-term outcomes.

METHODS

This report reviews the literature on developmental outcomes after pediatric heart transplantation.

RESULTS

Pediatric patients undergoing heart transplantation generally can be expected to have developmental outcomes in the low-normal range, consistent with outcomes seen in other children with complex congenital heart disease requiring surgical intervention. When these children reach school age, or return to school, most can be expected to function reasonably well in mainstream school settings. A significant minority will require additional educational assistance. Approximately 10% will have significant neurologic impairment. In school, particular attention should be paid to evaluating the child for deficits in arithmetic and verbal skills. Performance may be better than predicted from IQ testing. Behavioral issues are common, with depression, concerns about social competence, and attention difficulties most frequently endorsed. This may pre-date transplantation in those who undergo transplantation during childhood and may improve with time. Parents more often report problem behaviors than teachers. Family resources and family coping skills are also strongly correlated with the child's emotions and coping skills.

CONCLUSION

The pediatric heart transplant recipient's ability to transition from childhood into a happy and productive adult life can be significantly affected by his or her cognitive abilities, learning experiences, sense of self, and emotions. Attention to these factors is an important part of caring for these children.

Postmortem intracranial neuropathology in children following cardiac transplantation

At Loma Linda University Children's Hospital, the medical information of 405 pediatric patients who received orthotopic cardiac transplantation were reviewed. Of those who died (n=136), 86% (n=117) underwent postmortem examinations, and the brain was examined in 61% (n=82, male=39). The number and type of intracranial lesions present were compiled, and these were matched to underlying functional cardiac disease categories. Intracranial abnormalities were present in 87%. Infarct was the most common primary central nervous system pathology in hypoplastic left heart syndrome (41%) but was also observed frequently in children with obstructive lesions (37%), cyanotic disease (31%), or cardiac shunting (29%). Secondary findings included extraparenchymal hemorrhage in obstructive lesions (31%); hypoxic changes occurred in 15% of patients with cyanotic disease and in 14% of those with cardiac shunting. Thirty-three percent of children with restrictive lesions had no neuropathology reported. Postmortem examination brain weights were matched against age and sex norms, with 29% of females and 36% of males below two standard deviations. These findings revealed that intracranial pathology was present in the majority of transplanted children who underwent postmortem examination, and that infarctive changes constituted the most common neuropathologic abnormality. Additionally, a number of children had significantly reduced brain weight.

Clinical outcomes and secondary diagnoses for infants born with hypoplastic left heart syndrome

OBJECTIVE

To explore clinical outcomes and secondary diagnoses present at discharge for infants born with hypoplastic left heart syndrome (HLHS), from a national perspective.

METHODS

We examined hospitalizations for infants < or =30 days of age who were born with HLHS, using hospital discharge data from the 1997 Kids Inpatient Database. To explore treatment choices, clinical outcomes, and resource use, we used International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedure codes to classify discharges according to type of surgical intervention versus no surgical intervention. To investigate outcomes in more detail, we identified secondary diagnoses noted at discharge, using International Classification of Diseases, 9th Revision, Clinical Modification codes, and stratified results according to type of surgical intervention.

RESULTS

Of a total of 550 patients with HLHS, 234 underwent the Norwood procedure, 17 underwent orthotopic heart transplantation, and 106 died in the hospital with no reported surgical intervention. Although we found no demographic variables to be significantly associated with the type of treatment received, discharged patients who died without surgical intervention were significantly more likely to have received care in hospitals identified as small (odds ratio [OR]: 1.5; 95% confidence interval [CI]: 1.03-3.1) or not children's hospitals (OR: 2.02; 95% CI: 1.13-3.6). Secondary diagnoses of cardiac arrest (OR: 2.0; 95% CI: 1.1-3.4) and seizures (OR: 2.6; 95% CI: 1.2-5.5) occurred more frequently in orthotopic heart transplantation cases than in Norwood procedure cases.

CONCLUSIONS

These data from a national perspective reflect outcomes of infants with HLHS during a time when rates of initial survival after surgical intervention were considered to be improved. These findings may be useful to clinicians when they are considering and recommending initial medical and surgical strategies currently being proposed for the treatment of HLHS.