Experience With the Crescent• Right Atrial Jugular Dual Lumen Catheter for Pediatric Venovenous Extracorporeal Membrane Oxygenation: A Case Series

The Crescent dual lumen right atrial (RA) cannula has recently been introduced for the support of pediatric patients in need of venovenous extracorporeal membrane oxygenation (VV ECMO) support. We present the first pediatric case series illustrating utility of the Crescent RA cannula in the pediatric patient population at a single institution over a 10 month period. From December 2021 to August 2022, six pediatric patients were adequately supported on seven VV ECMO runs at our institution with the Crescent RA cannula. ECMO cannulation, circuit design, anticoagulation management, ECMO circuit pressures, flow rates, and recirculation were similar to our standard of care for VV ECMO. The Crescent RA cannula can be used safely and effectively to provide adequate support for pediatric patients requiring VV ECMO.

Surgical outcomes of infective endocarditis in pediatrics: Moving the needle to a contemporary, multidisciplinary approach

BACKGROUND

Infective endocarditis (IE) is an uncommon disease in children that, when present, is accompanied by significant morbidity and mortality. The presence of congenital heart disease often complicates management. The aim of the present study is to describe the characteristics and outcomes of children undergoing surgery for IE.

METHODS

A retrospective chart review from 2004 to 2020 was conducted to identify consecutive patients younger than age 20 years with IE undergoing surgery.

RESULTS

A total of 94 patients with IE were identified, of whom 47 underwent surgery at a median age of 16.7 years. Thirty-one patients (65.95%) had congenital heart disease. Vegetation and embolic phenomena occurred in 41 and 29 patients (87.23% and 61.7%), respectively, with the brain as most common location (57.1%). Native valve involvement had a greater tendency to embolize (P < .001). Staphylococcus spp was the most common organism (49%). The mitral valve was the most affected (31.9%). Seven (14.9%) patients had multivalvar involvement and valve replacement was the most common procedure performed (37 patients; 78.7%). There were 3 operative deaths (6.4%). Median length of hospital stay was 21 days. Risk factors for prolonged hospital stay were time to surgery in days (P < .001) and native valvar involvement (P = .05). Five patients (10.6%) had postoperative recurrent IE. Survival at 1 and 5 years was 93.6% and 89.4%, respectively.

CONCLUSIONS

Children with IE can undergo surgery with acceptable results. The morbidity, but not mortality, is driven by embolic complications. Staphylococcus spp and native valve involvement are significant risk factors. VIDEO ABSTRACT.

Methylprednisolone for Heart Surgery in Infants - A Randomized, Controlled Trial

BACKGROUND

Although perioperative prophylactic glucocorticoids have been used for decades, whether they improve outcomes in infants after heart surgery with cardiopulmonary bypass is unknown.

METHODS

We conducted a multicenter, prospective, randomized, placebo-controlled, registry-based trial involving infants (<1 year of age) undergoing heart surgery with cardiopulmonary bypass at 24 sites participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database. Registry data were used in the evaluation of outcomes. The infants were randomly assigned to receive prophylactic methylprednisolone (30 mg per kilogram of body weight) or placebo, which was administered into the cardiopulmonary-bypass pump-priming fluid. The primary end point was a ranked composite of death, heart transplantation, or any of 13 major complications. Patients without any of these events were assigned a ranked outcome based on postoperative length of stay. In the primary analysis, the ranked outcomes were compared between the trial groups with the use of odds ratios adjusted for prespecified risk factors. Secondary analyses included an unadjusted odds ratio, a win ratio, and safety outcomes.

RESULTS

A total of 1263 infants underwent randomization, of whom 1200 received either methylprednisolone (599 infants) or placebo (601 infants). The likelihood of a worse outcome did not differ significantly between the methylprednisolone group and the placebo group (adjusted odds ratio, 0.86; 95% confidence interval [CI], 0.71 to 1.05; P = 0.14). Secondary analyses (unadjusted for risk factors) showed an odds ratio for a worse outcome of 0.82 (95% CI, 0.67 to 1.00) and a win ratio of 1.15 (95% CI, 1.00 to 1.32) in the methylprednisolone group as compared with the placebo group, findings suggestive of a benefit with methylprednisolone; however, patients in the methylprednisolone group were more likely than those in the placebo group to receive postoperative insulin for hyperglycemia (19.0% vs. 6.7%, P<0.001).

CONCLUSIONS

Among infants undergoing surgery with cardiopulmonary bypass, prophylactic use of methylprednisolone did not significantly reduce the likelihood of a worse outcome in an adjusted analysis and was associated with postoperative development of hyperglycemia warranting insulin in a higher percentage of infants than placebo. (Funded by the National Center for Advancing Translational Sciences and others; STRESS ClinicalTrials.gov number, NCT03229538.).

Preemptive stenting of the left pulmonary artery during Comprehensive Stage 2 procedure does not impact Fontan candidacy

Objective

Pulmonary artery reconstruction during comprehensive stage 2 (CS2) procedure can be challenging. Since 2017, we have employed preemptive left pulmonary artery (LPA) stenting. We hypothesized that LPA stenting promotes adequate growth and without compromising Fontan candidacy. Herewith, we report our midterm results.

Methods

From 2002 to 2020, 159 patients underwent CS2. Patients were divided as follows: no stent (n = 122; Group 1) and perioperative LPA stent (n = 37; Group 2). Group 2 was subdivided according to unplanned stent (n = 17; Group 2a) or preemptive stent (n = 20; Group 2b). Relevant perioperative data was reviewed. Nonparametric statistics were utilized.

Results

Median age and weight at surgery and hospital length of stay after CS2 did not differ between groups. Median cardiopulmonary bypass and crossclamp times were significantly greater in Group 1 (265 vs 243 minutes [P = .021] and 46 vs 26 minutes [P = .008]). In-hospital mortality was similar between Groups 1 and 2 (9.0% vs 18.9%, respectively [P = .1348]). Group 2b demonstrated a superior survival compared to Group 2a (P = .0335) but not Group 1 (P > .9999). Preemptive stenting significantly increased median hilar LPA diameter at CS2 exit angiogram compared with no stenting (P < .0001). Groups 2a and 2b significantly increased the pre-Fontan diameter of the hilar LPA when compared with Group 1 (6.1 and 6.8 vs 5.7 mm, respectively [P < .0001]). A further 120 patients underwent Fontan operation (75%). Median follow-up for Groups 1 and 2 were 7.4 and 3.0 years, respectively.

Conclusions

Perioperative LPA stenting during CS2 does not adversely affect pulmonary growth. Preemptive stenting seems advantageous for LPA growth in preparation for Fontan completion.

Echocardiographic changes in patients with a cylinder mitral valve replacement: Preliminary analysis

AIMS

Cylinder mitral valve construct (cMVC) is new technique for replacing the mitral valve compared to more traditional mitral valve replacement (MVR) procedures. Goal of this study was to describe echocardiographic changes over time in patients undergoing a cMVC. Secondary goal was to compare echocardiographic changes in patients that underwent a cMVC to a group of patients that underwent a MVR.

METHODS

Retrospective analysis of patients undergoing a cMVC was performed. Demographics, discharge echocardiogram, and recent echocardiogram vales were evaluated. Age matched patients undergoing a MVR were assessed. Discharge and recent echocardiographic parameters were compared within the cMVC group. cMVC and MVR values were compared between groups.

RESULTS

Five cMVC patients were studied. Age at surgery for the cMVC was 4.3 ± 4.2 years (median 2.2, .8-10.3 years). Time interval from hospital discharge echocardiogram to the most recent echocardiogram was 1.2 ± .7 years (median 1.0, .6-2.0 years). Mean mitral valve gradient significantly increased over time (3.6 ± 3.0 mm Hg vs 7.6 ± 2.9 mm Hg). There were significant improvements in left ventricular diameters, systolic sphericity index, shortening fraction, and ejection fraction over time. There were no significant differences in demographics, discharge echocardiogram values, and follow up echocardiogram values between the cMVC and MVR groups.

CONCLUSION

In conclusion, echocardiographic indices of left ventricular function improved over time in patients undergoing cMVC. In addition, there were no significant differences between cMVC and MVR patients in echocardiographic values. Studies with a larger patient sample with longer follow up are needed to determine if cMVC continues to have comparable echocardiographic results to MVR.

Tricuspid Valve and Right Ventricular Function Throughout the Hybrid Palliation Strategy for Hypoplastic Left Heart Syndrome and Variants

BACKGROUND

Tricuspid valve (TV) and right ventricular (RV) function are major determinants of morbidity and mortality in patients with hypoplastic left heart syndrome (HLHS). We sought to retrospectively evaluate these parameters throughout the hybrid palliation strategy.

METHODS

From 2002 to 2018, 203 patients with HLHS and variants presented for hybrid stage I (HS1). Echocardiographic evaluation of tricuspid regurgitation (TR) and RV function was assessed at multiple time points. Clinical outcomes including tricuspid valvuloplasty, transplantation, and death were reviewed.

RESULTS

The most prevalent HLHS subtype was aortic atresia/mitral atresia. The presence of significant TR and/or RV dysfunction was 14.78% and 9.36%, respectively, at the time of initial HS1. There were 185 survivors following HS1 (91.13%, n = 185/203), while 147 patients underwent comprehensive stage II or bidirectional Glenn shunt (72.41%, n = 147/203). Tricuspid valvuloplasty was undertaken in nine patients (4.86%, n = 9/185). Ultimately, 100 patients underwent the Fontan procedure. The odds of development of significant TR and/or RV dysfunction were not statistically different throughout the stages of palliation (TR: odds ratio [OR] = 0.14-0.25, P = .5260; RV dysfunction: OR = 0.02-0.13, P = .3992). However, the risk of death and/or transplant was 2.5- to 3.8-fold when either were present alone or in combination (TR: OR = 2.58, P = .0356; RV dysfunction: OR = 3.84, P = .0262). Transplant-free survival at 15 years was 44.8%.

CONCLUSION

Following hybrid palliation for HLHS, the majority of survivors have normal RV and TV functions. Tricuspid valvuloplasty was required in few patients. Once significant TR and/or RV dysfunction ensues, there is a two- to three-fold risk of death and/or transplant.

Outcomes of children with congenital heart disease implanted with ventricular assist devices: An analysis of the Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs)

BACKGROUND

The reported ventricular assist device (VAD) experience in the pediatric congenital heart disease (CHD) population is limited. We sought to describe contemporary use and outcomes of VADs in children with CHD and compare these outcomes to those of non-CHD children.

METHODS

Patients enrolled in the Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) between September 19, 2012 through June 30, 2017 were included. CHD was classified as biventricular vs single ventricle (Stages 1, 2, or 3). Outcomes were compared between groups and multivariable analysis was used to identify factors associated with mortality on the device.

RESULTS

Among the 471 patients enrolled, 108 (24%) had CHD (45 biventricular and 63 single ventricle). CHD patients were younger (5.7 ± 5.7 years vs 9.8 ± 6.5 years; p < 0.0001) and smaller (0.8 ± 0.5 m² vs 1.2 ± 0.7 m²; p < 0.0001) compared with non-CHD patients. CHD patients were more likely to receive a paracorporeal continuous-flow VAD (36.1% vs 12.9%; p < 0.0001) and less likely to receive an implantable continuous-flow VAD (27.8% vs 55.0%; p < 0.0001) compared with non-CHD patients. After 6 months on a VAD, CHD patients had higher mortality (36.4% vs 12.1%) and a lower transplantation rate (29.1% vs 59.9%) than non-CHD patients (p < 0.0001). In the multivariable analysis, CHD was the factor most strongly associated with mortality on VAD (hazard ratio [HR] = 2.9; p < 0.0001), whereas the factors implantable continuous-flow device and high-volume center were protective (HR = 0.3, p < 0.0001, and HR = 0.6, respectively; p = 0.02).

CONCLUSIONS

VAD use in children with CHD is associated with increased mortality and decreased transplant rates compared to children without CHD. For the subgroup of children with CHD who received implantable continuous-flow VADs, survival rates were higher and comparable to those of children without CHD. Increased experience correlated with better survival in pediatric VADs.

Pulmonary Vein Stenosis in Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

OBJECTIVE

To quantify outcomes of infants (<1 year of age) diagnosed with pulmonary vein stenosis (PVS).

STUDY DESIGN

MEDLINE (PubMed), Scopus, and Web of Science were searched through February 1, 2017, with no language restrictions. Publications including infants diagnosed with primary PVS, defined as the absence of preceding intervention(s), were considered. The study was performed according to Meta-analysis of Observational Studies in Epidemiology guidelines, the Systematic Reviews, and Meta-Analysis checklist, and registered prospectively. The quality of selected reports was critically examined. Data extraction was independently performed by multiple observers with outcomes agreed upon a priori. Data were pooled using an inverse variance heterogeneity model with incidence of mortality the primary outcome of interest.

RESULTS

Forty-eight studies of 185 infants were included. Studies were highly diverse with regards to the participants, interventions, and outcomes reported. The median (range) age at diagnosis was 5.0 (0.1-11.6) months. Pooled mortality was 58.5% (95% CI 49.8%-67.0%, I² = 21.4%). We observed greater mortality incidence among infants with 3 or 4 vein stenoses than in those with 1 or 2 vein stenoses (83.3% vs 36.1%; P < .01). We observed greater mortality among infants with bilateral than unilateral disease (78.7% vs 26.0%; P < .01).

CONCLUSIONS

Studies of primary PVS during infancy are highly variable in their methodological quality and estimates of clinical outcomes; therefore, estimates of prognosis remain uncertain. Multicenter, interdisciplinary collaborations, including alignment of key outcome measurements, are needed to answer questions beyond the scope of available data.

Continuous-Flow LVAD Support Causes a Distinct Form of Intestinal Angiodysplasia

Rationale:

The objective of this autopsy study was to determine whether gastrointestinal angiodysplasia develops during continuous-flow left ventricular assist device (LVAD) support.

Objective:

LVAD support causes pathologic degradation of von Willebrand factor (vWF) and bleeding from gastrointestinal angiodysplasia at an alarming rate. It has been speculated that LVAD support itself may cause angiodysplasia. The relationship to abnormal vWF metabolism is unknown. We tested the hypothesis that abnormal gastrointestinal vascularity develops during continuous-flow LVAD support.

Methods and Results:

Small bowel was obtained from deceased humans, cows, and sheep supported with a continuous-flow LVAD (n=9 LVAD, n=11 control). Transmural sections of jejunum were stained with fluorescein isothiocyanate–conjugated isolectin-B4 for endothelium to demarcate vascular structures and quantify intestinal vascularity. Paired plasma samples were obtained from humans before LVAD implantation and during LVAD support (n=41). vWF multimers and degradation fragments were quantified with agarose and polyacrylamide gel electrophoresis and immunoblotting. Abnormal vascular architecture was observed in the submucosa of the jejunum of human patients, cows, and sheep supported with a continuous-flow LVAD. Intestinal vascularity was significantly higher after LVAD support versus controls (5.2±1.0% versus 2.1±0.4%, P =0.004). LVAD support caused significant degradation of high–molecular-weight vWF multimers (–9±1%, P <0.0001) and accumulation of low–molecular-weight vWF multimers (+40±5%, P <0.0001) and vWF degradation fragments (+53±6%, P <0.0001).

Conclusions:

Abnormal intestinal vascular architecture and LVAD-associated vWF degradation were consistent findings in multiple species supported with a continuous-flow LVAD. These are the first direct evidence that LVAD support causes gastrointestinal angiodysplasia. Pathologic vWF metabolism may be a mechanistic link between LVAD support, abnormal angiogenesis, gastrointestinal angiodysplasia, and bleeding.

Custom extracellular matrix cylinder mitral valve in a pediatric patient

Mitral valve construction using extracellular matrix (ECM) is a relatively new procedure. In this case, a 15-month-old boy with a history of severe mitral valve regurgitation secondary to endocarditis underwent mitral valve surgery. Mitral valve repair was not possible, and thus, a 17 mm extracellular matrix cylinder valve (ECM-CV) was constructed for valve replacement. The ECM-CV is clearly imaged using echocardiography, especially three-dimensional imaging, that helped define valve function. As the use of ECM for valve construction increases, echocardiography will play an essential role in evaluating the function and mechanics of these novel valves.

Employment after heart transplantation among adults with congenital heart disease

OBJECTIVE

Adults with congenital heart disease may require heart transplantation for end-stage heart failure. Whereas heart transplantation potentially allows adults with congenital heart disease to resume their usual activities, employment outcomes in this population are unknown. Therefore, we investigated the prevalence and predictors of work participation after heart transplantation for congenital heart disease.

DESIGN

Retrospective review of a prospective registry.

SETTING

United Network for Organ Sharing registry of transplant recipients in the United States.

PATIENTS

Adult recipients of first-time heart transplantation with a primary diagnosis of congenital heart disease, performed between 2004 and 2015.

INTERVENTIONS

None.

OUTCOME MEASURES

Employment status reported by transplant centers at required follow-up intervals up to 5 y posttransplant.

RESULTS

Among 470 patients included in the analysis (mean follow-up: 5 ± 3 y), 127 (27%) worked after transplant, 69 (15%) died before beginning or returning to work, and 274 (58%) survived until censoring, but did not participate in paid work. Multivariable competing-risks regression analysis examined characteristics associated with posttransplant employment, accounting for mortality as a competing outcome. In descriptive and multivariable analysis, pretransplant work participation was associated with a greater likelihood of posttransplant employment, while the use of Medicaid insurance at the time of transplant was associated with a significantly lower likelihood of working after transplant (subhazard ratio compared to private insurance: 0.55; 95% confidence interval: 0.32, 0.95; P = .032).

CONCLUSIONS

Employment was rare after heart transplantation for congenital heart disease, and was significantly less common than in the broader population of adults with congenital heart disease. Differences in return to work were primarily related to pretransplant employment and the use of public insurance, rather than clinical characteristics.

Perioperative care in an adolescent patient with heparin-induced thrombocytopenia for placement of a cardiac assist device and heart transplantation: case report and literature review

Heparin-induced thrombocytopenia (HIT) can cause life-threatening complications following the administration of heparin. Discontinuation of all sources of heparin exposure and the use of alternative agents for anticoagulation are necessary when HIT is suspected or diagnosed. We present the successful use of bivalirudin anticoagulation in an adolescent patient during cardiopulmonary bypass who underwent both placement of a left ventricular assist device and subsequent heart transplantation within a 36-hour period. The pathophysiology and diagnosis of HIT are reviewed, previous reports of the use of direct thrombin inhibitors for cardiac surgery are presented, and potential dosing regimens for bivalirudin are discussed.

Venovenous ECMO Support in an Infant With Single Ventricle Physiology and Catastrophic Pulmonary Venous Abnormalities

Extracorporeal membrane oxygenation (ECMO) is an accepted treatment modality for life support refractory to conventional efforts in neonates with complex congenital heart lesions. Cannulation for ECMO can be accomplished by venovenous (VV) access where patients receive primarily respiratory support or venoarterial (VA) access which provides complete cardiopulmonary support. VV ECMO delivered by a single-vessel cannulation with a dual-chamber venous cannula allows for respiratory support while the patient remains dependent upon intrinsic cardiac function to support hemodynamics. We present a case of support of a newborn with single ventricle physiology and intraparenchymal near-atresia of the pulmonary veins using VV ECMO.

Pretransplant Panel Reactive Antibodies and Lung Transplant Outcomes in Children

Background Pre-lung transplant (LTx) panel reactive antibody (PRA) levels are associated with adverse outcomes in adult LTx recipients, but their impact in pediatric LTx recipients is unknown. Methods The United Network for Organ Sharing registry was queried from 2004 to 2013 to compare survival between pediatric LTx recipients with PRA class I and II levels = 0 versus > 0. Results Overall, 333 pediatric LTx recipients had data on class I or II PRA and were included in the analysis. Univariate analysis demonstrated that PRA > 0 was not associated with survival benefit for class I (hazard ratio [HR] = 0.985; 95% confidence interval [CI]: 0.623, 1.555; p = 0.947) or class II (HR = 1.080; 95% CI: 0.657, 1.774; p = 0.762) PRA. Multivariate Cox models confirmed no significant association with mortality hazard for both class I (HR = 1.230; 95% CI: 0.641, 2.363; p = 0.533) and class II (HR = 0.847; 95% CI: 0.359, 1.997; p = 0.704) PRA. Multivariate logistic regression models identified no association between class I or class II and acute rejection within 3 years of LTx. Conclusions Pretransplant class I and II PRA levels > 0 were not associated with mortality or acute rejection in pediatric LTx recipients.

Potential Molecular Mechanism of Retrograde Aortic Arch Stenosis in the Hybrid Approach to Hypoplastic Left Heart Syndrome

BACKGROUND

The hybrid palliation for hypoplastic left heart syndrome has emerged as an alternative approach to the Norwood procedure. The development of patent ductus arteriosus (PDA) in-stent stenosis can cause retrograde aortic arch stenosis (RAAS), leading to significant morbidity. This study aimed to identify potential mechanisms of PDA in-stent stenosis contributing to RAAS.

METHODS

Tissues from stented PDAs were collected from 17 patients undergoing comprehensive stage II repair between 2009 and 2014. Patients requiring RAAS intervention based on cardiology-surgery consensus were defined as RAAS(+) (n = 10), whereas patients without any RAAS intervention were defined as RAAS(-) (n = 7). Tissues were examined by quantitative polymerase chain reaction analysis for vascular smooth muscle cell (VSMC) differentiation and proliferation markers.

RESULTS

Patient characteristics were hypoplastic left heart syndrome with aortic atresia in 6 and with aortic stenosis in 3; unbalanced atrioventricular canal in 3; double-inlet left ventricle/transposition of the great arteries in 3; and double-outlet right ventricle in 2. VSMC differentiation markers (β-actin, SM22, and calponin) and signaling pathways for VSMC modulation (transforming growth factor-β1, Notch, and platelet derived growth factor-BB) were significantly higher in the RAAS(+) than in RAAS(-) patients. The proliferation marker Ki67 was increased in RAAS(+) patients. Cell cycle markers were comparable in both groups.

CONCLUSIONS

Increased VSMC differentiation and proliferation markers suggest a mechanism for inward neointima formation of the PDA in RAAS. The apparent lack of change in cell cycle markers is contrary to coronary artery in-stent stenosis, suggesting further targets should be examined. Combined primary in vitro PDA cell culture and proteomics can be strong tools to elucidate targets to reduce PDA in-stent stenosis for RAAS in the future.

Aortic root thrombosis with coronary embolization following neo-aortic reconstruction in a child with hypoplastic left heart syndrome

In the recent era, the diagnosis, treatment options, postoperative management and outcomes of infants born with hypoplastic left heart syndrome (HLHS) have undergone dramatic changes. As is the case with many other novel treatment modalities used for congenital heart diseases, data concerning the long-term outcomes and complications of the various strategies become gradually more available as the numbers of survivors grow. In general, complications of the three-stage surgical palliation used for HLHS tend to occur most commonly following the first-stage surgery. Post-stage 2 complications are substantially less common, and centre on the procedure itself and the unique physiology of the cavopulmonary connection. In the following case report, we describe a relatively rare adverse outcome that occurred following a stage 2 surgery in the form of native aortic root thrombosis extending to the coronary arteries. The selected methods of treatment used in the catheterization laboratory and later in the operating theatre, as well as its outcomes are described.

Adult survivor with repaired complete pentalogy of Cantrell

Pentalogy of Cantrell is a very rare condition with very high mortality. We present an adult survivor with a classic pentad who underwent sequential surgical repairs as a neonate, child, and young adult. He required home mechanical ventilation for the first two years of life and subsequently needed noninvasive nocturnal ventilation as an adult.

Outcomes in pediatric lung transplant recipients receiving adult allografts

BACKGROUND

Clinical practice in the United States has no restrictions in allocating lungs from adult donors to pediatric recipients.

METHODS

The United Network for Organ Sharing database was queried from 1987 to 2013 for pediatric lung transplant recipients (aged less than 18 years) to assess survival using continuous donor age in years and two donor age groups, ≥ 18 years and > 30 years, for analysis.

RESULTS

Of 930 pediatric lung transplants, basic survival analysis identified a mortality hazard when adult lung allografts were transplanted into pediatric recipients; however, multivariate Cox models demonstrated that continuous donor age (hazard ratio [HR] 1.004, 95% confidence interval [CI]: 0.992-1.015, p = 0.524) as well as both categoric age groups, donor 18 years or older (HR 0.967, 95% CI: 0.714-1.309, p = 0.827) and donor older than 30 years (HR 1.168, 95% CI: 0.815-1.673, p = 0.398), did not significantly influence the risk for death. Moreover, propensity score matching analysis confirmed a lack of association of mortality risk with donor age ≥ 18 years (HR 1.129, 95% CI: 0.696-1.831, p = 0.623) and donor age > 30 years (HR 1.050, 95% CI: 0.569-1.937, p = 0.876). Bronchiolitis obliterans syndrome (BOS) was found to be a significant predictor of mortality in univariate analysis (HR 2.033, 95% CI: 1.639-2.521, p < 0.001), but the hazard of BOS did not vary across donor age categories.

CONCLUSIONS

Adult donor lung allografts appear not to negatively affect survival in pediatric lung transplant recipients when considering confounders, and do not influence survival through an increased hazard for the development of BOS.

Survival in children on extracorporeal membrane oxygenation at the time of lung transplantation

Limited data exist on ECMO at the time of LTx in children. The UNOS database was queried from 2000 to 2013 for pediatric lung transplant recipients (<18 yr) to assess post-transplant survival of patients on ECMO at the time of LTx. Of 587 pediatric recipients with 17 on ECMO, 585 were used for univariate and Kaplan-Meier function analysis, 535 for multivariate Cox models, and 24 for propensity score matching. Univariate Cox (HR = 1.777; 95% CI: 0.658, 4.803; p = 0.257) and Kaplan-Meier function (log-rank test: chi-square (df = 1): 1.32, p = 0.250) analyses did not identify a survival difference between ECMO and non-ECMO, while multivariate Cox models (HR = 1.821; 95% CI: 0.654, 5.065; p = 0.251) did not demonstrate an increased risk for death. Propensity score matching analysis (HR = 1.500; 95% CI: 0.251, 8.977; p = 0.657) also failed to demonstrate a significantly increased hazard ratio. Using a contemporary cohort of pediatric lung transplant recipients, the use of ECMO at the time of lung transplantation did not negatively impact survival.

Hyperbilirubinemia complicating plasma-free hemoglobin and antifactor Xa level monitoring on venovenous extracorporeal membrane oxygenation

Optical spectrophotometric methods are used to detect both plasma-free hemoglobin and antifactor Xa level, so hyperbilirubinemia can interfere with the measurement of both the monitoring laboratory tests for extracorporeal membrane oxygenation (ECMO) due to similar absorbance wavelengths. We present a seven-year-old child with acute respiratory failure on venovenous ECMO who developed an acute increase in plasma-free hemoglobin and undetectable antifactor Xa level due to acute hyperbilirubinemia from hepatic dysfunction related to antifungal therapy.

Extracellular matrix pleural tent for persistent air leak and air space in a child after upper lobectomy

Creation of a pleural tent is effective in reducing persistent air leaks after pulmonary resection. I report a case of a pleural-like tent being created out of extracellular matrix to treat a persistent air leak in child after upper lobectomy for a large congenital pulmonary airway malformation type II. Over the next year, ipsilateral lung expansion and growth occurred with near complete resolution of the apical air space.

Variability in noncardiac surgical procedures in children with congenital heart disease

BACKGROUND

The purpose of this study was to examine the volume and variability of noncardiac surgeries performed in children with congenital heart disease (CHD) requiring cardiac surgery in the first year of life.

METHODS

Patients who underwent cardiac surgery by 1 year of age and had a minimum 5-year follow-up at 22 of the hospitals contributing to the Pediatric Health Information System database between 2004 and 2012 were included. Frequencies of noncardiac surgical procedures by age 5 years were determined and categorized by subspecialty. Patients were stratified according to their maximum RACHS-1 (Risk Adjustment in Congenital Heart Surgery) category. The proportions of patients across hospitals who had a noncardiac surgical procedure for each subspecialty were compared using logistic mixed effects models.

RESULTS

8857 patients underwent congenital heart surgery during the first year of life, 3621 (41%) of whom had 13,894 noncardiac surgical procedures by 5 years. Over half of all procedures were in general surgery (4432; 31.9%) or otolaryngology (4002; 28.8%). There was significant variation among hospitals in the proportion of CHD patients having noncardiac surgical procedures. Compared to children in the low risk group (RACHS-1 categories 1-3), children in the high-risk group (categories 4-6) were more likely to have general, dental, orthopedic, and thoracic procedures.

CONCLUSIONS

Children with CHD requiring cardiac surgery frequently also undergo noncardiac surgical procedures; however, considerable variability in the frequency of these procedures exists across hospitals. This suggests a lack of uniformity in indications used for surgical intervention. Further research should aim to better standardize care for this complex patient population.

Cardiac tamponade: new technology masking an old nemesis

A 16-year-old male patient underwent bilateral pulmonary embolectomy complicated by reperfusion injury and acute respiratory distress syndrome requiring venovenous extracorporeal membrane oxygenation support using a bicaval double-lumen catheter. A unique hemodynamic profile developed consistent with tamponade but without an associated decrease in venovenous extracorporeal membrane oxygenation pump flow, improved venovenous extracorporeal membrane oxygenation circuit preload, and decreased recirculation. The use of newer bicaval double-lumen catheters can result in old problems presenting in new ways and require clinicians to be ever vigilant.

Quality improvement methodologies increase autologous blood product administration

Whole blood from the heart-lung (bypass) machine may be processed through a cell salvaging device (i.e., cell saver [CS]) and subsequently administered to the patient during cardiac surgery. It was determined at our institution that CS volume was being discarded. A multidisciplinary team consisting of anesthesiologists, perfusionists, intensive care physicians, quality improvement (QI) professionals, and bedside nurses met to determine the challenges surrounding autologous blood delivery in its entirety. A review of cardiac surgery patients' charts (n = 21) was conducted for analysis of CS waste. After identification of practices that were leading to CS waste, interventions were designed and implemented. Fishbone diagram, key driver diagram, Plan-Do-Study-Act (PDSA) cycles, and data collection forms were used throughout this QI process to track and guide progress regarding CS waste. Of patients under 6 kg (n = 5), 80% had wasted CS blood before interventions, whereas those patients larger than 36 kg (n = 8) had 25% wasted CS before interventions. Seventy-five percent of patients under 6 kg who had wasted CS blood received packed red blood cell transfusions in the cardiothoracic intensive care unit within 24 hours of their operation. After data collection and didactic education sessions (PDSA Cycle I), CS blood volume waste was reduced to 5% in all patients. Identification and analysis of the root cause followed by implementation of education, training, and management of change (PDSA Cycle II) resulted in successful use of 100% of all CS blood volume.

Video Fluoroscopy Swallow Study and Nutritional Support During Ambulatory Venovenous Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplantation

We present the successful completion of a video fluoroscopy swallow study and subsequent nutritional plan of a child bridged to lung transplantation with ambulatory venovenous (VV) extracorporeal membrane oxygenation (ECMO). With a limited number of programs bridging pediatric patients to lung transplantation with VV ECMO, a better understanding of nutritional support is needed to provide optimal care to this patient population awaiting organ donation.

Surveillance transbronchial biopsies in infant lung and heart-lung transplant recipients

There are limited published data on surveillance TBB for the identification of allograft rejection in infants after lung or heart-lung transplantation. We performed a retrospective review of children under one yr of age who underwent lung or heart-lung transplant at our institution. Since 2005, four infants were transplanted (three heart-lung and one lung). The mean age (±s.d.) at the time of transplant was 5.5 ± 2.4 (range 3-8) months. A total of 16 surveillance TBB procedures were completed in both inpatient and outpatient settings, with a range of 3-7 performed per patient. A minimum of five acceptable tissue pieces with expanded alveoli were obtained in 81% (13/16) of TBB procedures and a minimum of three pieces in 88% (14/16). There was no evidence of acute allograft rejection in 88% (14/16) of TBB procedures. One TBB procedure yielded two tissue specimens demonstrating A2 acute allograft rejection. One TBB procedure failed to yield tissue with sufficient alveoli. Additionally, B-grade assessment identified B0 in 50% (8/16), B1R in 12% (2/16), and BX (ungradeable or insufficient sample) in 38% (6/16) of biopsy procedures, respectively. In conclusion, TBB may be safely performed as an inpatient and outpatient procedure in infant lung and heart-lung transplant recipients and may provide adequate tissue for detecting acute allograft rejection and small airway inflammation.

Cross-country transfer between two children's hospitals of a child using ambulatory extracorporeal membrane oxygenation for bridge to lung transplant

With a limited number of pediatric lung transplant programs, the transfer of patients will be required for appropriate candidates. Pediatric patients have been successfully transferred using extracorporeal membrane oxygenation (ECMO) with no previous reports using ambulatory single-site venovenous (VV) ECMO via a bicaval dual-lumen (BCDL) catheter as a method for transport to a lung transplant center in order to bridge to lung transplantation. Therefore, we present the successful transfer of a 13-yr-old female on ambulatory VV ECMO between two free-standing children's hospitals and then bridged to bilateral lung transplantation.

Contrast transthoracic echocardiography and the placement of a bicaval dual-lumen catheter in a Swine model of venovenous extracorporeal membrane oxygenation

Placement of a bicaval dual-lumen (BCDL) catheter demands sophisticated visualization in patients to assure proper positioning in order to administer single-site venovenous extracorporeal membrane oxygenation (VV ECMO). Large animal models are needed and thus appropriate procedures to assure anatomic and functional cannula placement would assist in experimental design and procedures. This report describes the use of agitated blood and saline transthoracic contrast echocardiography to confirm appropriate placement and function of the BCDL catheter in a swine model of VV ECMO. Five consecutive common crossbred piglets had confirmation using this technique with assurances of cannulation while not significantly altering experimental time and procedures. Researchers studying VV ECMO in large animal models may want to consider this method of confirmation of BCDL catheter placement.

Gram-negative infection and bronchiectasis in lung transplant recipients with bronchiolitis obliterans syndrome

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) after lung transplantation manifests as a gradual decline in forced expiratory volume in 1 second. Bronchiectasis is often seen but occurs at variable rates with the underlying pathogenesis being unclear.

OBJECTIVE

We completed a study to determine whether lower airway infection with gram-negative bacilli was associated with the development of bronchiectasis in lung transplant recipients with BOS.

METHODS

A retrospective review of 17 lung transplant recipients (age: 28 ± 7 years, range: 13 to 40 years) in a patient population transplanted for cystic fibrosis (CF) 82% (14/17), bronchiolitis obliterans 12% (2/17), and sarcoidosis 6% (1/17) was completed. Each patient completed pulmonary function testing and underwent annual computed tomographic imaging of the chest for surveillance posttransplant at a single transplant center.

RESULTS

Bronchiectasis was present in 70% (12/17) of patients whereas 94% (16/17) of patients had varying severity of BOS: 1 (n = 7), 2 (n = 3), and 3 (n = 6). All 12 patients with bronchiectasis had an allograft gram-negative rod infection and 92% (11/12) of them had BOS.

CONCLUSIONS

The presence of bronchiectasis in lung transplant recipients with BOS was associated with a gram-negative bacterial airway infection of the allograft in a small cohort of predominately lung transplant recipients with CF.

Electrotonic remodeling following myocardial infarction in dogs susceptible and resistant to sudden cardiac death

Passive electrical remodeling following myocardial infarction (MI) is well established. These changes can alter electrotonic loading and trigger the remodeling of repolarization currents, a potential mechanism for ventricular fibrillation (VF). However, little is known about the role of passive electrical markers as tools to identify VF susceptibility post-MI. This study investigated electrotonic remodeling in the post-MI ventricle, as measured by myocardial electrical impedance (MEI), in animals prone to and resistant to VF. MI was induced in dogs by a two-stage left anterior descending (LAD) coronary artery ligation. Before infarction, MEI electrodes were placed in remote (left circumflex, LCX) and infarcted (LAD) myocardium. MEI was measured in awake animals 1, 2, 7, and 21 days post-MI. Subsequently, VF susceptibility was tested by a 2-min LCX occlusion during exercise; 12 animals developed VF (susceptible, S) and 12 did not (resistant, R). The healing infarct had lower MEI than the normal myocardium. This difference was stable by day 2 post-MI (287 +/- 32 Omega vs. 425 +/- 62 Omega, P < 0.05). Significant differences were observed between resistant and susceptible animals 7 days post-MI; susceptible dogs had a wider electrotonic gradient between remote and infarcted myocardium (R: 89 +/- 60 Omega vs. S: 180 +/- 37 Omega). This difference increased over time in susceptible animals (252 +/- 53 Omega at 21 days) due to post-MI impedance changes on the remote myocardium. These data suggest that early electrotonic changes post-MI could be used to assess later arrhythmia susceptibility. In addition, passive-electrical changes could be a mechanism driving active-electrical remodeling post-MI, thereby facilitating the induction of arrhythmias.

Early time course of myocardial electrical impedance during acute coronary artery occlusion in pigs, dogs, and humans

Changes in myocardial electrical impedance (MEI) and physiological end points have been correlated during acute ischemia. However, the importance of MEI's early time course is not clear. This study evaluates such significance, by comparing the temporal behavior of MEI during acute total occlusion of the left anterior descending coronary artery in anesthetized humans, dogs, and pigs. Here, interspecies differences in three MEI parameters (baseline, time to plateau onset, and plateau value normalized by baseline) were evaluated using Kruskal-Wallis ANOVA and post hoc tests ( P < 0.05). Noteworthy differences in the MEI time to plateau onset were observed: In dogs, MEI ischemic plateau was reached after 46.3 min (SD 12.9) min of occlusion, a significantly longer period compared with that of pigs and humans [4.7 (SD 1.2) and 4.1 min (SD 1.9), respectively]. However, no differences could be observed between both animal species regarding the normalized MEI ischemic plateau value (15.3% (SD 4.7) in pigs, vs. 19.6% (SD 2.6) in dogs). For all studied MEI parameters, only swine values resembled those of humans. The severity of myocardial supply ischemia, resulting from coronary artery occlusion, is known to be dependent on collateral flow. Thus, because dogs possess a well-developed collateral system (unlike humans or pigs), they have shown superior resistance to occlusion of a coronary artery. Here, the early MEI time course after left anterior descending coronary artery occlusion, represented by the time required to reach ischemic plateau, was proven to reflect such interspecies differences.

Correlation of autologous skeletal myoblast survival with changes in left ventricular remodeling in dilated ischemic heart failure

OBJECTIVES

The effect of autologous skeletal myoblast transplantation has not been rigorously studied in the setting of end-stage ischemic heart failure free of concomitant coronary revascularization. The aims of the present study were to determine autologous skeletal myoblast survival and its effects on left ventricular function and remodeling in sheep with dilated ischemic heart failure.

METHODS

Ischemic heart failure (left ventricular ejection fraction, 30% +/- 2%; left ventricular end-systolic volume index, 82 +/- 9 mL/m2) was created in sheep (n = 11) with serial left circumflex coronary artery microembolizations. Instruments were inserted for the long-term determination of left ventricular global and regional dimensions, hemodynamics, and pressure-volume analysis after autologous skeletal myoblast transplantation (approximately 3.0 x 10(8) myoblasts; heart failure plus autologous skeletal myoblast group, n = 5) or without (heart failure-control group, n = 6). Measurements were performed in conscious animals.

RESULTS

Autologous skeletal myoblast-derived skeletal muscle was found in all injected animals at 6 weeks. In ischemic heart failure, autologous skeletal myoblast cardiomyoplasty failed to improve systolic (left ventricular ejection fraction, 29% +/- 4%; dP/dT(max), 2863 +/- 152 mm Hg/s; end-systolic elastance, 1.6 +/- 0.22) or diastolic (left ventricular end-diastolic pressure, 21 +/- 2 mm Hg; time constant of relaxation (Tau), 34 +/- 4 ms; dP/dT(min), -1880 +/- 68 mm Hg/s) function. There was, however, attenuation in the left ventricular dilatation after autologous skeletal myoblast transplantation (change in end-systolic volume index, 14% +/- 4% vs 32% +/- 6%; P < .05). The effects of autologous skeletal myoblast-derived skeletal muscle were exclusive to the left ventricular short-axis dimension and dependent on autologous skeletal myoblast survival (R2 = 0.59, P = .006, n = 11).

CONCLUSIONS

Autologous skeletal cardiomyoplasty was able to attenuate left ventricular remodeling in sheep with end-stage ischemic heart failure.