Combined Norwood and cavopulmonary shunt as the first palliation in late presenters with hypoplastic left heart syndrome and single-ventricle lesions.

OBJECTIVE: A primary cavopulmonary shunt as a component of the initial Norwood palliation could be an option in patients with hypoplastic left heart syndrome and single-ventricle lesions. We present our initial experience with this approach in carefully selected patients with unrestricted pulmonary blood flow and low pulmonary vascular resistance. METHODS: The study included 16 patients; the mean age was 137.9 ± 84.2 days. All patients underwent a Norwood palliation consisting of atrial septectomy, Damus-Kaye-Stansel connection, and arch augmentation in addition to the cavopulmonary shunt as the initial palliation. RESULTS: The mean preoperative pulmonary to systemic blood flow (Qp/Qs) ratio on room air (n = 9) and with 100% oxygen (n = 8) was 5.3 ± 3.2 and 8.6 ± 4.3, respectively. The mean pulmonary vascular resistance on room air (n = 10) and 100% oxygen (n = 9) was 4.8 ± 3.1 and 1.7 ± 0.97 WU/m2, respectively. Delayed chest closure was needed in 12 patients, and 6 patients required postoperative inhaled nitric oxide. One patient underwent takedown of the cavopulmonary shunt and construction of the right ventricle to pulmonary artery conduit after 1 month. The mean intensive care unit stay was 18.9 ± 15.4 days. There were 2 in-hospital deaths (48 hours and 8 days after surgery) and 2 postdischarge deaths (6 months and 2 years after hospital discharge). Seven patients have undergone the Fontan completion successfully, and 5 patients await further surgery. CONCLUSIONS: First-stage Norwood palliation with cavopulmonary shunt for patients with hypoplastic left heart syndrome or single-ventricle lesions is feasible in late presenters with low pulmonary vascular resistance.

Purpose-Built Transcatheter Cavopulmonary Anastomosis Device Requirements: Multi-Modality Imaging Evaluation.

BACKGROUND/PURPOSE: Patients with a functional single ventricle undergo multiple, palliative open-heart surgeries. This includes a superior cavopulmonary anastomosis or bidirectional Glenn shunt. A less-invasive transcatheter approach may reduce morbidity. METHODS/MATERIALS: We analyzed pre-Glenn X-ray contrast angiography (XA), cardiac computed tomography (CT), and cardiac magnetic resonance (CMR) studies. RESULTS: Over an eleven-year period (1/2007 - 6/2017), 139 Glenn surgeries were performed at our institution. The typical age range at surgery was 59 - 371 days (median = 163; IQR = 138 - 203). Eight-nine XA, ten CT, and ten CMR studies obtained from these patients were analyzed. Cephalad SVC measurements (millimeters) were 7.3 ± 1.7 (XA), 7.7 ± 1.6 (CT) and 6.9 ± 1.8 (CMR). RPA measurements were 7.3 ± 1.9 (XA), 7.4 ± 1.6 (CT) and 6.6 ± 1.9 (CMR). Potential device lengths were 10.9 ± 6 - 17.4 ± 6.4 (XA), 10.1 ± 2.1 - 17.7 ± 2.4 (CT) and 17.3 ± 4. - 23.7 ± 5.5 (CMR). SVC-RPA angle (degrees) was 132.9 ± 13.2 (CT) and 140 ± 10.2 (MRI). Image quality of all CT (100%), almost all XA (SVC 100%, RPA 99%), and most MRI (SVC 80%, RPA 90%) were deemed sufficient. Parametric modeling virtual fit device with 10 mm diameter and 20 - 25 mm length was ideal. CONCLUSIONS: Ideal transcatheter cavopulmonary shunt device for the typical patient would be 10 mm in diameter and 20-25 mm in length.

Factors associated with mortality or transplantation versus Fontan completion after cavopulmonary shunt for patients with tricuspid atresia.

OBJECTIVE: Tricuspid atresia with normally related great vessels (TA) is considered the optimal substrate for the Fontan pathway. The factors associated with death or transplantation after cavopulmonary shunt (CPS) are underappreciated. We aimed to determine factors associated with CPS-Fontan interstage death/transplantation versus transition to Fontan in TA. METHODS: A total of 417 infants younger than 3 months of age with TA were enrolled (January 1999 to February 2020) from 40 institutions into the Congenital Heart Surgeons' Society TA cohort. Parametric competing risk methodology was used to determine factors associated with the competing end points of death/transplantation without Fontan completion, and transition to Fontan. RESULTS: CPS was performed in 382 patients with TA; of those, 5% died or underwent transplantation without transition to Fontan and 91% transitioned to Fontan by 5 years after CPS. Prenatal diagnosis (hazard ratio [HR], 0.74; P < .001) and pulmonary artery band (PAB) at CPS (HR, 0.50; P < .001) were negatively associated with Fontan completion. Preoperative moderate or greater mitral valve regurgitation (HR, 3.0; P < .001), concomitant mitral valve repair (HR, 11.0; P < .001), PAB at CPS (HR, 3.0; P < .001), postoperative superior vena cava interventions (HR, 9.0; P < .001), and CPS takedown (HR, 40.0; P < .001) were associated with death/transplantation. CONCLUSIONS: The mortality rate after CPS in patients with TA is notable. Those with preoperative mitral valve regurgitation remain a high-risk group. PAB at the time of CPS being associated with both increased risk of death and decreased Fontan completion may represent a deleterious effect of antegrade pulmonary blood flow in the CPS circulation.

Attrition between the superior cavopulmonary connection and the Fontan procedure in hypoplastic left heart syndrome.

OBJECTIVE: We investigated the incidence and predictors of failure to undergo the Fontan in children with hypoplastic left heart syndrome who survived superior cavopulmonary connection. METHODS: The cohort consists of all patients with hypoplastic left heart syndrome who survived to hospital discharge after superior cavopulmonary connection between 1988 and 2017. The primary outcome was attrition, which was defined as death, nonsuitability for the Fontan, or cardiac transplantation before the Fontan. Subjects were excluded if they were awaiting the Fontan, were lost to follow-up, or underwent biventricular repair. The study period was divided into 4 eras based on changes in operative or medical management. Attrition was estimated with 95% confidence intervals, and predictors were identified using adjusted, logistic regression models. RESULTS: Of the 856 hospital survivors after superior cavopulmonary connection, 52 died, 7 were deemed unsuitable for Fontan, and 12 underwent or were awaiting heart transplant. Overall attrition was 8.3% (71/856). Attrition rate did not change significantly across eras. A best-fitting multiple logistic regression model was used, adjusting for superior cavopulmonary connection year and other influential covariates: right ventricle to pulmonary artery shunt at Norwood (P < .01), total support time at superior cavopulmonary connection (P < .01), atrioventricular valve reconstruction at superior cavopulmonary connection (P = .02), performance of other procedures at superior cavopulmonary connection (P = .01), and length of stay after superior cavopulmonary connection (P < .01). CONCLUSIONS: In this study spanning more than 3 decades, 8.3% of children with hypoplastic left heart syndrome failed to undergo the Fontan after superior cavopulmonary connection. This attrition rate has not decreased over 30 years. Use of a right ventricle to pulmonary artery shunt at the Norwood procedure was associated with increased attrition.

Surgical Timing and Outcomes of Unilateral Versus Bilateral Superior Cavopulmonary Anastomosis: An Analysis of Pediatric Heart Network Public Databases.

Requiring bilateral superior cavopulmonary anastomosis (bSCPA) instead of unilateral superior cavopulmonary anastomosis (uSCPA) could influence surgical timing and outcomes. We compared surgical timing and outcomes for patients who underwent uSCPA to those who underwent bSCPA through use of the Pediatric Heart Network's public datasets for the Infant Single Ventricle trial and Single Ventricle Reconstruction trial. There was no statistically significant difference in median age at SCPA (158 vs. 150 days, p = 0.68), hospital length of stay (LOS) (7 vs. 7 days, p = 0.74), intensive care unit (ICU) LOS (4 vs. 5 days, p = 0.53), time requiring ventilator support (2 vs. 2 days, p = 0.51), or oxygen saturation at discharge (82 vs. 81%, p = 0.22) between the uSCPA and bSCPA groups, respectively. However, sub-analysis comparing only those who underwent early SCPA, at < 120 days of age, revealed significantly longer hospital LOS (8 vs. 13 days, p = 0.04), ICU LOS (5 vs. 11 days, p = 0.01), and time requiring ventilator support (2 vs. 4 days, p = 0.03) for the early bSCPA group when compared to the early uSCPA group. A multivariable logistic regression revealed bSCPA to be the only significant predictor of prolonged hospital LOS for patients who underwent early SCPA (odds ratio 4.1, 95% CI 1.2-14.2). Overall, there was no difference in surgical timing or outcome measures between uSCPA and bSCPA. However, early bSCPA, performed at < 120 days, had worse outcome measures than early uSCPA. Delaying elective bSCPA until at least 120 days of age could minimize morbidity in infants with bilateral superior venae cavae.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations.

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Arteriovenous fistula creation for hypoxia after single ventricle palliation: A single-institution experience and literature review.

BACKGROUND: Hypoxia is a common and sometimes severe morbidity of single ventricle congenital heart disease (CHD). Creation of an arteriovenous fistula (AVF) is occasionally performed for patients after superior or total cavopulmonary connection (SCPC or TCPC) in an attempt to improve oxygen saturations. Despite previous reports, AVF creation is a rare palliation with inadequately defined benefits and risks. We sought to determine changes in peripheral oxygen saturation (SpO2 ) and risk of adverse event after AVF creation in children with single ventricle CHD at our institution. METHODS: We conducted a retrospective chart review of patients with a history of single ventricle palliation and history of surgical AVF creation who were seen at our tertiary care center from 1996 to 2017. RESULTS: A total of seven patients were included in our study. SpO2 for the overall cohort did not significantly increase after AVF creation (pre-AVF 79.1 ± 6.9%, post-AVF 82.7 ± 6.0% [P = .23]). SpO2 trended up for large shunts (>5 mm) (pre-AVF 75.0 ± 7.6%, post-AVF 84.0 ± 5.3% [P = .25]). SpO2 did not improve for small shunts (≤5 mm) (pre-AVF 82.3 ± 6.5%, post-AVF 81.0 ± 8.5% [P = .50]). The 12-month overall and transplant-free survival were 85.7% and 71.4%, respectively. Freedom from AVF-related complication (cephalic edema, thrombotic occlusion) was 51.4% at 12 months. CONCLUSION: Palliative AVF creation for patients with single ventricle CHD and hypoxia does not universally improve SpO2 and is prone to early complications. Despite a lack of durable benefit and known risks, AVF creation remains a reasonable palliation for a subset of patients after SCPC who are not candidates for TCPC, or potentially as a bridge to heart transplantation.

The Bilateral Bidirectional Glenn Operation as a Risk Factor Prior to Fontan Completion in Complex Congenital Heart Disease Patients.

INTRODUCTION: The Glenn procedure is generally performed as a second-stage palliative procedure toward the completion of Fontan circulation in patients with a functionally univentricular heart. Safe Fontan completion requires normal ventricular function, competent atrioventricular valves, normal pulmonary arteries anatomy, and low pulmonary vascular resistances (PVRs), which is merely an estimation that considers both lungs as a single unit. Clinical observations revealed that patients who previously underwent bilateral bidirectional cavopulmonary anastomosis (b-BCPA) had a stormier postoperative course in respect to other patients with previous unilateral BCPA (u-BCPA) postoperatively after Fontan completion. This retrospective study was designed to compare and analyze the outcomes of patients following Fontan completion with previous u-BCPA versus b-BCPA. PATIENTS AND METHODS: A total of 98 patients were divided into two groups based on the presence or absence of bilateral superior vena cava (SVC). Group 1 included 80 patients with unilateral SVC, and group 2 included 18 patients with bilateral SVC. Univariate and multivariate (SPSS) analyses were performed with regard to mortality and failure. P value of <.05 was considered as significant. RESULTS: Prior to the total cavopulmonary anastomosis operation, the G1 and G2 had similar demographic and physiological findings, ages and weights were 4.3 ± 1.72 years and 15.0 ± 3.71 kg in G1 and 4.8 ± 3.21 years and 17.5 ± 9.76 kg in G2. Mean end-diastolic ventricular pressures (in mm Hg) were 10.50 ± 2.86 in G1 and 10.28 ± 3.07 in G2 and the mean PVRs (in Woods units) were 1.66 ± 1.29 in G1 and 1.49 ± 0.82 in G2. The Stormy postoperative course, Fontan failure, and early mortality were all significantly higher in G2 in respect to G1 ( P value <.05). G1 mortality rate was 3.7%, 3 patients of 80, while in G2, the mortality rate was 22%, 4 patients of 18. Late Fontan failure rates were 6% for G1 patients where two patients developed pulmonary hypertension, two patients developed heart failure, and one patient had protein losing enteropathy (PLE), and 22% for the G2 patients of which two patients developed heart failure, one patient had PLE, and one patient had persistent low systemic venous saturation. CONCLUSIONS: Our results have demonstrated that patients after b-BCPA might have a tendency for worse outcomes upon Fontan completion. The b-BCPA is associated with pulmonary artery bifurcation stenosis and presents multiple sources of pulmonary blood flow where conventional PVR calculation might be imprecise and misleading since it considers the lungs as a single unit. Therefore, b-BCPA engenders correction of the conventional PVR calculation to consider each lung separately. Furthermore, the surgical approach for patients with persistent left SVC and univentricular heart should be modified.

Patients With Systemic Right Ventricle Are at Higher Risk of Chylothorax After Cavopulmonary Connections.

BACKGROUND: Chylothorax is a rare but severe complication after pediatric cardiac surgical procedures and is related to significant morbidity and mortality. It is suspected to be more frequent after single-ventricle staged palliation procedures, but focused studies on chylothorax in patients with univentricular heart physiology are scarce. METHODS: From January 2008 to December 2016, a total of 289 patients underwent 376 cavopulmonary connection (CPC) procedures over 9 years (superior cavopulmonary connection [SCPC], 199; Fontan completion, 177). Patients were classified according to whether they had a chylothorax (group 1) or not (group 2). Chylothorax was confirmed on a pleural fluid test. RESULTS: The rate of chylothorax after a CPC procedure was 19.7% (74 of 376): 15.6% after SCPC and 24.3% after Fontan completion. Mean follow-up was 4.3 ± 0.1 years. Systemic right ventricle was more frequent in group 1 than in group 2 (64.9% vs 46%, respectively; p = 0.003). Chylothorax was associated with a higher rate of early reoperation (p = 0.001) and late failure of the CPC (p < 0.001). Late mortality was also more frequent in group 1 than in group 2 (17.6% vs 4.3%; p < 0.001). By multivariate analysis, having a systemic right ventricle was the only identified predictor for the development of chylothorax (odds ratio, 2.49; 95% confidence interval, 1.4 to 4.7; p = 0.004). CONCLUSIONS: The incidence of chylothorax in patients undergoing the univentricular pathway procedure is higher than previously suggested. Having a systemic right ventricle is a significant risk factor for developing a chylothorax after a CPC.

Neonatal Myocardial Perfusion in Right Ventricle Dependent Coronary Circulation: Clinical Surrogates and Role of Troponin-I in Postoperative Management Following Systemic-to-Pulmonary Shunt Physiology.

Right ventricle dependent coronary circulation (RVDCC) in pulmonary atresia with intact ventricular septum (PA/IVS) is associated with significant mortality risk in the immediate post-operative period following the initial stage of surgical palliation. Prognosis remains guarded during the interstage period towards conversion to the superior cavopulmonary shunt physiology. Current literature is scarce regarding this specific patient population. Cardiac troponin-I is widely used as a marker of coronary ischemia in adults, but its use for routine monitoring of neonatal myocardial tissue injury due to supply/demand perfusion mismatch is, yet to be determined. We sought to evaluate the clinical correlation of cTnl perioperative use in a PA/IVS RVDCC case and assess its interplay with established clinical, echocardiographic, and laboratory variables in guiding a real-time (dynamic) management strategy following systemic-to-pulmonary shunt palliation.

Late Follow-up of Patients Submitted to Total Cavopulmonary Derivation: Clinical Aspects, Reinterventions, and Complications Interfering in Morbidity and Mortality.

OBJECTIVE: To identify main complications in outpatient follow-up, as well as factors before or during operation that may interfere in patient's evolution. METHODS: Retrospective study of patients submitted to total cavopulmonary shunt with extracardiac conduit from 2000 to 2014 at the Hospital do Coração (São Paulo, Brazil) and who underwent clinical follow-up at this institution. RESULTS: One hundred and fifty surgeries were performed and 59 patients maintained outpatient follow-up. The mean age of these patients at the time of surgery was 4.45 years (median of 45 months) and 70.2% of them were males. Among the patients undergoing outpatient follow-up, postoperative time at evaluation ranged from 10 days to 145 months; 30 (50.8%) patients had single left ventricle and 29 (49.2%) had single right ventricle (48.2% of these presented with hypoplastic left heart syndrome [HLHS]). Patients with single left ventricle had a higher percentage of reintervention-free survival, but without statistically significant difference. 40% of the patients had no complications and 35% of them presented with thrombosis at some point in the follow-up period, with ventricular dysfunction being the second most frequently found complication (15% of cases), mainly among patients with single right ventricle morphology (P=0.04). Between the patients currently under follow-up, 20 (35%) of them had been evaluated by ultrasonography and had some degree of hepatic congestion and/or hepatomegaly. 16.7% of the patients with such alteration had HLHS (P=0.057). CONCLUSION: Except for the right ventricular morphology, no other factor has been shown to interfere in late evolution after total cavopulmonary shunt.

Early Diagnostic Features of Left-to-Right Shunt-Induced Pulmonary Arterial Hypertension in Piglets.

BACKGROUND: We aimed to establish early diagnostic characteristics of left-to-right shunt-induced pulmonary arterial hypertension (PAH) in a piglet model. METHODS: A shunt-induced PAH in piglets (n = 9) was successfully established by anastomosis of vascular prosthesis from aorta to pulmonary artery with follow-up for 6 months by a number of diagnostic procedures. RESULTS: PAH developed with mean pulmonary arterial pressure [PAP] of 30.2 ± 6.0 mm Hg immediately after operation and 33.5 ± 8.7 mm Hg at 3 months after operation with pulmonary vascular resistance increased to 4.0 ± 0.9 Wood units. There was a weak correlation on systolic PAP between catheterization and echocardiography but the Tei index was significantly correlated to systolic PAP. Magnetic resonance imaging demonstrated that the end-diastolic volume index, systolic volume index, ejection fraction of the ventricle, and ventricular mass index were sensitive indices. Technetium-99m single-photon emission computed tomography indicated increased blood flow in the upper and middle zones of both lungs. Positron emission tomography-computed tomography (PET-CT) demonstrated a higher kilo count (kct) of 18F-fluorodeoxyglucose in the right ventricular wall and both chambers at 3 months postoperatively (right ventricular wall: 5,708.3 ± 428.4 versus 3,965.5 ± 138.6 preoperatively, p = 0.003; both chambers: 2,963.6 ± 219.4 versus 1,710.1 ± 35.4 preoperatively, p < 0.05) as well as at 6 months for both chambers (p < 0.05). CONCLUSIONS: In this successful left-to-right shunt-induced PAH model in piglets, sensitive indices including the Tei index, systolic volume index, ejection fraction, ventricular mass index, lung perfusion, and glycometabolism by PET-CT in early PAH are determined. For the first time, we report that glycometabolism by PET-CT is useful in early diagnosis. These indices may be used for the early diagnosis in the left-to-right shunt-induced PAH.

Major Adverse Events Following Over-Shunting Are Associated With Worse Outcomes Than Major Adverse Events After a Blocked Systemic-to-Pulmonary Artery Shunt Procedure.

OBJECTIVES: Causes of major adverse event after systemic-to-pulmonary shunt procedure are usually shunt occlusion or over-shunting. Outcomes categorized on the basis of these causes will be helpful both for quality improvement and prognostication. DESIGN: Retrospective cohort analysis of children who underwent a systemic-to-pulmonary shunt after excluding those who had it for Norwood or Damus-Kaye-Stansel procedure. SETTING: The Royal Children's Hospital, Melbourne, VIC, Australia. PATIENTS: From 2008 to 2015, 201 children who had a systemic-to-pulmonary shunt were included. INTERVENTIONS: Major adverse event is defined as one or more of cardiac arrest, chest reopening, or requirement for extracorporeal membrane oxygenation. Study outcome is a "composite poor outcome," defined as one or more of acute kidney injury, necrotizing enterocolitis, brain injury, or in-hospital mortality. MEASUREMENTS AND MAIN RESULTS: Median (interquartile range) age was 12 days (6-38 d) and median (interquartile range) time to major adverse event was 5.5 hours (2-17 hr) after admission. Overall, 36 (18%) experienced a major adverse event, and reasons were over-shunting (n = 17), blocked shunt (n = 13), or other (n = 6). Fifteen (88%) in over-shunting group suffered a cardiac arrest compared with two (15%) in the blocked shunt group (p < 0.001). The composite poor outcome was seen in 15 (88%) in over-shunting group, four (31%) in the blocked shunt group, and 56 (34%) in those who did not experience a major adverse event (p < 0.001). By multivariable analysis, predictors for composite poor outcome were major adverse event due to over-shunting (no major adverse event-reference; over-shunting odds ratio, 18.60; 95% CI, 3.87-89.4 and shunt-block odds ratio, 1.57; 95% CI, 0.46-5.35), single ventricle physiology (odds ratio, 4.70; 95% CI, 2.34-9.45), and gestation (odds ratio, 0.84/wk increase; 95% CI, 0.74-0.96). CONCLUSIONS: Infants who suffer major adverse event due to over-shunting experience considerably poorer outcomes than those who experience events due to shunt block. A mainly hypoxic event with maintenance of systemic perfusion (as often seen in a blocked shunt) is less likely to result in poorer outcomes than those after a hypoxic-ischemic event (commonly seen in over-shunting).

Late follow-up of patients submitted to total cavopulmonary derivation: clinical aspects, reinterventions, and complications interfering in morbidity

Abstract Objective: To identify main complications in outpatient follow-up, as well as factors before or during operation that may interfere in patient's evolution. Methods: Retrospective study of patients submitted to total cavopulmonary shunt with extracardiac conduit from 2000 to 2014 at the Hospital do Coração (São Paulo, Brazil) and who underwent clinical follow-up at this institution. Results: One hundred and fifty surgeries were performed and 59 patients maintained outpatient follow-up. The mean age of these patients at the time of surgery was 4.45 years (median of 45 months) and 70.2% of them were males. Among the patients undergoing outpatient follow-up, postoperative time at evaluation ranged from 10 days to 145 months; 30 (50.8%) patients had single left ventricle and 29 (49.2%) had single right ventricle (48.2% of these presented with hypoplastic left heart syndrome [HLHS]). Patients with single left ventricle had a higher percentage of reintervention-free survival, but without statistically significant difference. 40% of the patients had no complications and 35% of them presented with thrombosis at some point in the follow-up period, with ventricular dysfunction being the second most frequently found complication (15% of cases), mainly among patients with single right ventricle morphology (P=0.04). Between the patients currently under follow-up, 20 (35%) of them had been evaluated by ultrasonography and had some degree of hepatic congestion and/or hepatomegaly. 16.7% of the patients with such alteration had HLHS (P=0.057). Conclusion: Except for the right ventricular morphology, no other factor has been shown to interfere in late evolution after total cavopulmonary shunt.

Life-threatening airway bleeding after palliation of single ventricle congenital heart disease.

OBJECTIVE: To describe acute and mid-term outcomes following presentation with, and treatment for, life-threatening airway bleeding (hemoptysis) in palliated single ventricle congenital heart disease (SV-CHD). METHODS: Case series of patients with SV-CHD who presented to a large congenital heart centre with hemoptysis between 2004 and 2015. RESULTS: Twenty-one episodes of hemoptysis occurred in 12 patients (58% female, median 10.5 (IQR 7.2, 16.4) years). First hemoptysis episode occurred after Fontan completion (n=8), after superior cavopulmonary anastomosis (SCPA, n=3) and in one shunt-dependent patient. Bronchoscopy was performed in conjunction with catheterisation in 14/21 (67%) initial catheterisations. A specific anatomic source of airway bleeding was identified in 95% of bronchoscopy cases and was uniformly distributed in all lobar segments. Transcatheter intervention with systemic-to-pulmonary collateral artery (SPC) occlusion was performed in 28/30 catheterisations. Apart from increased airway bleeding during interventional bronchoscopy (37%), there were no procedural complications. Median hospital length of stay was 9.0 (3.5, 14.5) days with patients undergoing 1.0 (1.0,2.0) catheterisations per episode of hemoptysis. Two SCPA patients did not survive to discharge. During a median follow-up of 32.5 (12.5, 87.5) months, freedom from mortality was 75%, with all three deaths occurring in the SCPA group by 4 months posthemoptysis. Recurrent hemoptysis occurred in 60% of patients. CONCLUSIONS: Despite the potentially life-threatening nature of hemoptysis in patients with SV-CHD, a policy of bronchoscopic evaluation and transcatheter treatment is safe and may contribute to low mortality at mid-term follow-up in Fontan patients. Hemoptysis in SCPA patients may portend a poor prognosis. Recurrent hemoptysis is common.

Incidence and Management of Thrombotic and Thromboembolic Complications Following the Superior Cavopulmonary Anastomosis Procedure: A Literature Review.

The objective of this literature review was to estimate the incidence of thrombosis and thromboembolism associated with the superior cavopulmonary anastomosis (SCPA) procedure and its variants and to examine current thromboprophylaxis regimens utilized. MEDLINE and EMBASE were searched from inception to August 2017 for all prospective and retrospective cohort studies explicitly reporting incidence of thrombosis, thromboembolism, or shunt occlusion in neonates, infants, and children undergoing 1 or more variants of the SCPA procedure. End points included thrombotic events and thromboembolic events (strokes and pulmonary embolisms) as primary outcomes, and overall mortality as a secondary outcome, at the last available follow-up time point. Of 1303 unique references identified, 13 cohort studies were deemed eligible. Reported incidence of thrombosis and thromboembolic events ranged from 0% to 28.0% and from 0% to 12.5%, respectively. Reported incidence of major bleeding events ranged from 0% to 2.9%. Reported overall mortality ranged from 2.5% to 50.5% across studies. Thromboprophylaxis protocols varied across institutions and studies, most commonly involving unfractionated heparin (UFH), warfarin, enoxaparin, acetylsalicylic acid (ASA), or combinations of ASA and warfarin, ASA and low-molecular-weight heparin (LMWH), UFH and LMWH, and UFH and ASA; several studies did not specify a protocol. Due to substantial variability in reported event rates, no clear correlation was identified between prophylaxis protocols and postoperative thrombotic complications. Despite guidance recommending postoperative UFH as standard practice, thromboprophylaxis protocols varied across institutions and studies. More robust trials evaluating different thromboprophylaxis regimens for the management of these patients are warranted.

Measurement of Dead Space Fraction Upon ICU Admission Predicts Length of Stay and Clinical Outcomes Following Bidirectional Cavopulmonary Anastomosis.

OBJECTIVES: Increased alveolar dead space fraction has been associated with prolonged mechanical ventilation and increased mortality in pediatric patients with respiratory failure. The association of alveolar dead space fraction with clinical outcomes in patients undergoing bidirectional cavopulmonary anastomosis for single ventricle congenital heart disease has not been reported. We describe an association of alveolar dead space fraction with postoperative outcomes in patients undergoing bidirectional cavopulmonary anastomosis. DESIGN: In a retrospective case-control study, we examined for associations between alveolar dead space fraction ([PaCO2 - end-tidal CO2]/PaCO2), arterial oxyhemoglobin saturation, and transpulmonary gradient upon postoperative ICU admission with a composite primary outcome (requirement for surgical or catheter-based intervention, death, or transplant prior to hospital discharge, defining cases) and several secondary endpoints in infants following bidirectional cavopulmonary anastomosis. SETTINGS: Cardiac ICU in a tertiary care pediatric hospital. PATIENTS: Patients undergoing bidirectional cavopulmonary anastomosis at our institution between 2011 and 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 191 patients undergoing bidirectional cavopulmonary anastomosis, 28 patients were cases and 163 were controls. Alveolar dead space fraction was significantly higher in the case (0.26 ± 0.09) versus control group (0.17 ± 0.09; p < 0.001); alveolar dead space fraction at admission was less than 0.12 in 0% of cases and was greater than 0.28 in 35% of cases. Admission arterial oxyhemoglobin saturation was significantly lower in the case (77% ± 12%) versus control group (83% ± 9%; p < 0.05). Sensitivity and specificity for future case versus control assignment was best when prebidirectional cavopulmonary anastomosis risk factors, admission alveolar dead space fraction (AUC, 0.74), and arterial oxyhemoglobin saturation (AUC, 0.65) were combined in a summarial model (AUC, 0.83). For a given arterial oxyhemoglobin saturation, the odds of becoming a case increased on average by 181% for every 0.1 unit increase in alveolar dead space fraction. Admission alveolar dead space fraction and arterial oxyhemoglobin saturation were linearly associated with prolonged ICU length of stay, hospital length of stay, duration of mechanical ventilation, and duration of thoracic drainage (p < 0.001 for all). CONCLUSIONS: Following bidirectional cavopulmonary anastomosis, alveolar dead space fraction in excess of 0.28 or arterial oxyhemoglobin saturation less than 78% upon ICU admission indicates an increased likelihood of requiring intervention prior to hospital discharge. Increasing alveolar dead space fraction and decreasing arterial oxyhemoglobin saturation are associated with increased lengths of stay.