Recent advances in the surgical management of the single ventricle pediatric patient

Impact of low birth weight on staged single-ventricle palliation

BACKGROUND

To assess the impact of low birth weight on early and late outcomes after staged palliation for single ventricle.

METHODS

Patients after stage 1 palliation for single ventricle in our institution were retrospectively included and divided into two weight groups: 2.5 kg or less (low birth weight) and more than 2.5 kg. The impact of low birth weight on mortality and on the progression to further palliation stages (bidirectional Glenn, stage 2, and total cavopulmonary connection, stage 3) was assessed.

RESULTS

A total of 452 patients were included. Patients with low birth weight (n = 37, 8 %) had more frequently associated prematurity and extracardiac anomalies. Early and inter-stage mortality after stage 1 was higher in patients with low birth weight, so that less of these patients reached the next palliation stage (57 % vs. 77 %, p = 0.01, and 38 % vs. 56 %, p = 0.05, for stage 2 and stage 3, respectively). After 5 years, overall survival was inferior in patients with low birth weight (48 % vs. 73 %, p < 0.001). Survival conditioned by stage 2 palliation was inferior in patients with low birth weight compared to the reference group (76 % vs. 89 % after 5 years, p = 0.04). Low birth weight was a risk factor for death in most patients' subgroups, inclusive those with restricted pulmonary blood flow after a systemic-to-pulmonary shunt procedure.

CONCLUSIONS

During staged palliation of single-ventricle physiology, low birth weight has a detrimental impact on survival extending to beyond stage 2. This study calls for increased vigilance of these patients beyond the first interstage.

Outcomes Following Norwood Procedures: Analysis of a "Small Volume" Program

BACKGROUND

Institutional survival following Norwood procedures is traditionally correlated with a center's surgical volume. Multiple single and multi-institutional studies conducted at large-volume centers have recently demonstrated improved survival following Norwood procedures. We report both short- and long-term outcomes at a single, small-volume institution and comment on factors potentially influencing outcomes at this institution.

METHODS

All patients undergoing Norwood procedures from January 1, 2005, to January 1, 2020, at our institution were included in this study. Kaplan-Meier survival and Cox regression risk factor analyses were performed in addition to first interstage risk factor scoring to compare observed versus expected survival.

RESULTS

The cohort included 113 patients. Kaplan-Meier freedom from death or transplant was 88%, 80%, and 76% at 1, 5, and 10 years, respectively. Freedom from death following hospital discharge after Norwood procedures was 94%, 87%, and 83% at 1, 5, and 10 years, respectively. The presence of genetic syndromes was a significant risk factor for mortality. First interstage observed-to-expected mortality following discharge was 0.57 (P = .04). Postoperative length of stay was comparable to that reported for the period 2015 to 2018 in the Society of Thoracic Surgeons Database.

CONCLUSIONS

Survival outcomes at this single, small-volume institution were similar to those reported by large-volume centers and multi-institutional collaborative studies. These results may be related to structural and functional features that have been demonstrated to influence outcomes in other studies. These factors are achievable by small-volume programs with sufficient resource allocation.

Perioperative Echocardiography in the Adult With Congenital Heart Disease

Survival of patients with congenital heart disease has significantly improved over the last 2 decades, confronting interventionalists, surgeons, anesthesiologists, cardiologists, and intensivists with often unfamiliar complex pathophysiology in the perioperative setting. Aside from cardiac catheterization, echocardiography has become the main imaging modality in the hospitalized adult with congenital heart disease. The great variety of congenital lesions and their prior surgical management challenges practitioners to generate optimal imaging, reporting, and interpretation of these complex anatomic structures. Standardization of echocardiographic studies can not only provide significant benefits in the surveillance of these patients, but also facilitate understanding of pathophysiologic mechanism and assist clinical management in the perioperative setting. Knowledge in obtaining and interpreting uniform imaging protocols is essential for the perioperative clinician. In this publication, the authors review current international consensus recommendations on echocardiographic imaging of adults with congenital heart disease and describe the fundamental components by specific lesion. The authors will emphasize key aspects pertinent to the clinical management when imaging these patients in the perioperative setting. The goal of this review is to familiarize the perioperative physician on how to structure and standardize echocardiographic image acquisition of congenital heart disease anatomy for optimal clinical management.

Survival After Norwood Procedure in High-Risk Patients

BACKGROUND

Multiple single-ventricle populations are noted to be at increased risk for mortality after the Norwood procedure. Preoperative risk factors include low birth weight, restrictive/intact atrial septum, obstructed pulmonary veins, ventricular dysfunction, and atrioventricular valve regurgitation. We report outcomes of the Norwood procedure in standard- and high-risk patients in the recent era.

METHODS

All patients born with hypoplastic left heart syndrome between 2006 and 2016 who underwent a Norwood procedure at our institution were included. Patient data were retrospectively reviewed, and Kaplan-Meier analysis was used to evaluate survival between groups.

RESULTS

The cohort included 177 patients. Fifty patients were determined high-risk preoperatively: low birth weight (n = 18), ventricular dysfunction/atrioventricular valve regurgitation (n = 13), intact or restrictive atrial septum/obstructed anomalous pulmonary venous return (n = 14), and multiple factors (n = 5). There were 2 (1.6%) deaths before Glenn in the standard-risk group, with a total of 10 (20%) from the high-risk groups (P < .0001). Survival at 1 year differed greatly between groups, with highest being standard risk at 89% and lowest in the intact septum/obstructed veins group at 54%. The difference between groups in long-term survival was significant (P < .001).

CONCLUSIONS

Outcomes after the Norwood procedure have improved for standard-risk patients. Those with preoperative risk factors account for most of the early deaths after the Norwood procedure. This high-risk status does not resolve after Glenn, because longer-term survival continues to diverge from the standard-risk group.

How Does One Safely Anesthetize a Univentricular Patient for Noncardiac Surgery?

As the surgical, perioperative, and pediatric management of univentricular patients advances, more anesthesiologists will see these challenging patients as children, teenagers, and adults come to the operating room for common noncar diac surgeries: tonsillectomy, appendectomy, labor and de livery, etc. The univentricular heart has 2 atrioventricular valves with 1 ventricular chamber or a large dominant ven tricle associated with a diminutive opposing ventricle. The common pathway of physiology is complete mixing of blood. Blood pressure and oxygen saturation are dependent on the ratio of pulmonary vascular resistance (PVR) to sys temic vascular resistance (SVR). A thorough history and physical examination give the anesthesiologist insight into what further laboratory evaluations and interventions are needed. The 3 key issues with respect to echocardiographic evaluation of the heart are ventricular function, atrioventric ular valve insufficiency, and pulmonary artery stenosis or distortion. After completion of the ventricular bypass proce dures, the hemodynamics rely on the homeostasis of the PVR/SVR ratio, ventricular performance, and oxygen deliv ery. Therefore, the univentricular physiology is best served by spontaneous ventilation. Intraoperative and postopera tive pain management is key to facilitating extubation of the patient's trachea and subsequently expediting recovery from surgery.

Influence of Morphology and Initial Surgical Strategy on Survival of Infants With Tricuspid Atresia

BACKGROUND

Tricuspid atresia (TA) is a heterogeneous single-ventricle anomaly in which initial presentation and, consequently, timing and mode of palliation vary based on morphology and degree of pulmonary or systemic outflow obstruction. We report current era palliation outcomes and examine whether morphologic and, subsequently, surgical factors influence survival.

METHODS

From 2002 to 2012, 105 infants with TA underwent surgical palliation. Competing risks analyses modeled events after first-stage surgery (Glenn versus death) and after Glenn (Fontan versus death) and examined risk factors affecting outcomes.

RESULTS

Seventy-eight patients (74%) required neonatal first-stage palliation, including modified Blalock-Taussig shunt (n = 46, 44%), Norwood (n = 18, 17%), and pulmonary artery band (n = 14, 13%), whereas 27 (26%) received primary Glenn as their initial surgery. Hospital mortality was 5 patients (4.8%). Competing risks models showed that by 1 year after first-stage surgery, 15% of patients had died and 83% had undergone Glenn. By 5 years after Glenn, 2% of patients had died and 80% had undergone Fontan. Overall 8-year survival was 84%. On multivariable analysis, risk factors for mortality were genetic/extracardiac anomalies (hazard ratio 7.0, 95% confidence interval: 2.4 to 20.6, p < 0.001) and pulmonary atresia (hazard ratio 4.4, 95% confidence interval: 1.6 to 12.2, p = 0.004). Survival was not affected by initial palliation type (p = 0.36), ventriculoarterial discordance (p = 0.25), systemic outflow obstruction (p = 0.84), or arch obstruction (p = 0.62).

CONCLUSIONS

Despite morphologic and physiologic variations necessitating different palliative sequences, multistage palliation outcomes of various TA subtypes are comparable and generally good, with the exception of patients with associated genetic/extracardiac anomalies. The bulk of mortality is interstage, indicating continued opportunity for improvement in monitoring and managing patients during this critical period.

Functional capacity following univentricular repair--midterm outcome

OBJECTIVE

Previous studies have seldom compared functional capacity in children following Fontan procedure alongside those with Glenn operation as destination therapy. We hypothesized that Fontan circulation enables better midterm submaximal exercise capacity as compared to Glenn physiology and evaluated this using the 6-minute walk test.

DESIGN AND PATIENTS

Fifty-seven children aged 5-18 years with Glenn (44) or Fontan (13) operations were evaluated with standard 6-minute walk protocols.

RESULTS

Baseline SpO(2) was significantly lower in Glenn patients younger than 10 years compared to Fontan counterparts and similar in the two groups in older children. Postexercise SpO(2) fell significantly in Glenn patients compared to the Fontan group. There was no statistically significant difference in baseline, postexercise, or postrecovery heart rates (HRs), or 6-minute walk distances in the two groups. Multiple regression analysis revealed lower resting HR, higher resting SpO(2) , and younger age at latest operation to be significant determinants of longer 6-minute walk distance. Multiple regression analysis also established that younger age at operation, higher resting SpO(2) , Fontan operation, lower resting HR, and lower postexercise HR were significant determinants of higher postexercise SpO(2) . Younger age at operation and exercise, lower resting HR and postexercise HR, higher resting SpO(2) and postexercise SpO(2) , and dominant ventricular morphology being left ventricular or indeterminate/mixed had significant association with better 6-minute work on multiple regression analysis. Lower resting HR had linear association with longer 6-minute walk distances in the Glenn patients.

CONCLUSIONS

Compared to Glenn physiology, Fontan operation did not have better submaximal exercise capacity assessed by walk distance or work on multiple regression analysis. Lower resting HR, higher resting SpO(2) , and younger age at operation were factors uniformly associated with better submaximal exercise capacity.

Cerebral hemorrhage and vasospasm in a child with congenital heart disease

INTRODUCTION

Intracerebral hemorrhages are relatively rare events in children and cerebral vasospasm after such hemorrhages is even more unusual. Children with structural congenital heart disease are particularly at risk for both thrombotic and embolic events but not to isolated hemorrhages.

DISCUSSION

We report a case of cerebral vasospasm in a child with structural congenital heart disease after a cerebral hemorrhage.

CONCLUSION

This case illustrates that this rare occurrence must be swiftly recognized and treated in order to maximize clinical outcome.

Dysfunction of atrial and B-type natriuretic peptides in congenital univentricular defects

OBJECTIVE

To examine whether children with univentricular defects have intrinsic dysfunction in the natriuretic peptide system.

METHODS

We compared plasma levels of the fluid-regulating hormone vasopressin (antidiuretic hormone), aldosterone, atrial natriuretic peptide, and brain natriuretic peptide in children with congenital univentricular and biventricular defects. We enrolled 27 patients with univentricular defects and 27 patients with biventricular cardiac defects. Children who underwent Fontan and Glenn procedures were considered as patients with univentricular cardiac defects; children who underwent repair of tetralogy of Fallot or subaortic stenosis were considered as controls with biventricular defects.

RESULTS

Preoperative plasma atrial natriuretic peptide, brain natriuretic peptide, antidiuretic hormone, and aldosterone were comparable in both groups. Although plasma cyclic guanosine monophosphate levels were comparable between groups, there was a significant correlation between molar concentrations of plasma cyclic guanosine monophosphate and plasma atrial natriuretic peptide ( r = 0.42) and brain natriuretic peptide ( r = 0.44) in the biventricular group, but not in the univentricular group ( r = 0.19 for atrial natriuretic peptide; r = 0.13 for brain natriuretic peptide). All patients had a significant postoperative increase in plasma antidiuretic hormone. A significant postoperative increase in plasma brain natriuretic peptide was found in the patients with biventricular, but not univentricular, defects. In contrast, a significant increase in plasma aldosterone was observed only in the patients with univentricular defects.

CONCLUSIONS

There were distinct differences between univentricular and biventricular groups in their perioperative plasma fluid-regulating hormone responses. Specifically, patients with univentricular defects may have abnormal natriuretic peptide secretion and function. The natriuretic dysfunction may be on the basis of hypoplastic ventricular development.

Where infants die: examination of place of death and hospice/home health care options in the state of Wisconsin

Infants (less than 1 year of age) have the highest death rates in the pediatric population, yet there is little published on hospice utilization for infant home deaths. We sought to describe: (1) where infants with a predisposing life-threatening condition are dying, (2) agency services available to dying infants and their families, and (3) utilization of these services for infants within the state of Wisconsin. We collected information from death certificates for infants whose cause of death was either congenital anomaly or condition of the perinatal period, such as hypoxic ischemic encephalopathy or prematurity. In addition, we surveyed all hospice and home health agencies in Wisconsin to determine their ability to serve and whether they were utilized for this same population. During 1992-1996 in Wisconsin, state records indicate that 2591 infants died: congenital anomalies or conditions of the perinatal period resulted in 1538 (60%) of these deaths. Of the 508 infant deaths from congenital anomalies, 46 (9%) occurred at home. Of the 1030 deaths from conditions of the perinatal period, 16 (1.5%) occurred at home. Only 36 (40%) of the 91 hospice/home health agencies that responded to our survey provided services to the pediatric population between 1992-1996. During this time, only 11 agencies provided care for 20 infant home deaths, comprising 32% of infant home deaths reported to the state in that same time period. In comparison to adults and older children, we found a low home death rate for infants with a life-threatening condition. To clarify these findings, we discuss barriers to infant home death.

Current management of infants and children with single ventricle anatomy

Children with single ventricle anatomy are among the most complicated and challenging patients encountered in pediatric cardiology. Current management involves staged surgical procedures, beginning with neonatal palliation and followed by a bidirectional cavopulmonary anastomosis in infancy and culminating in the Fontan procedure. The Fontan procedure, despite separating the circulation, remains a palliative procedure with many long-term concerns. This report discusses the staged surgical management of patients with single ventricle anatomy and the nursing issues relevant to each stage.