Results of the Double Switch Operation in Patients Who Previously Underwent Left Ventricular Retraining

BACKGROUND

Congenitally corrected transposition of the great arteries (CC-TGA) is a complex form of congenital heart disease that has numerous subtypes. While most patients with CC-TGA have a large ventricular septal defect (VSD) and pulmonary stenosis, there are some patients who have either no VSD or a highly restrictive VSD. These patients will require left ventricular (LV) retraining prior to double switch. The purpose of this study was to review our experience with the double switch procedure in patients who had previously undergone LV retraining.

METHODS

This was a retrospective review of a single institution experience with the double switch procedure in patients who had undergone LV retraining (2002-present).

RESULTS

Forty-five patients underwent double switch following LV retraining. Of these, 39 had an arterial switch with hemi-Mustard/bidirectional Glenn and six had a Senning. The median cross-clamp time was 135 min (range 71-272) and median bypass time was 202 min (range 140-430 min). Median hospital length of stay was eight days (range 4-108). There were no in-hospital deaths. Median duration of follow-up was 30 months (range 0-175). One patient subsequently underwent heart transplantation and died 65 months following double switch. At follow-up, 41 of the 44 survivors (93%) have normal or low normal LV function and 40 of the 44 survivors (91%) have no or trace mitral regurgitation.

CONCLUSIONS

The data demonstrate early and mid-term survival of 100% and 97%. Ninety-three percent had preserved LV function. These results suggest that patients with CC-TGA who undergo LV retraining and double switch can have excellent clinical outcomes.

Right Ventricular and Outflow Tract Functional Characteristics After Repair of Tetralogy of Fallot with Major Aortopulmonary Collaterals

This study describes right ventricle (RV) characteristics and right ventricle to pulmonary artery (RV-PA) conduit function pre- and post-repair in patients with tetraology of Fallot with major aortopulmonary collaterals (TOF/MAPCAs). We reviewed patients who underwent single-stage, complete unifocalization, and repair of TOF/MAPCAs between 2006 and 2019 with available pre- and early postoperative echocardiograms. For a subset of patients, 6-12 month follow-up echocardiogram was available. RV and left ventricle (LV) characteristics and RV-PA conduit function were reviewed. Wilcoxon signed rank test and McNemar's test were used. 170 patients were reviewed, 46 had follow-up echocardiograms. Tricuspid valve annular plane systolic excursion (TAPSE) Z-scores were reduced from pre- (Z-score 0.01) to post-repair (Z-score -4.5, p < 0.001), improved but remained abnormal at follow-up (Z-score -4.0, p < 0.001). RV fractional area change (FAC) and LV ejection fraction were not significantly different before and after surgery. Conduit regurgitation was moderate or greater in 11% at discharge, increased to 65% at follow-up. RV-PA conduit failure (severe pulmonary stenosis or severe pulmonary regurgitation) was noted in 61, and 63% had dilated RV (diastolic RV area Z-score > 2) at follow-up. RV dilation correlated with the severe conduit regurgitation (p = 0.018). Longitudinal RV function was reduced after complete repair of TOF/MAPCAs, with decreased TAPSE and preserved FAC and LV ejection fraction. TAPSE improved but did not normalize at follow-up. Severe RV-PA conduit dysfunction was observed prior to discharge in 11% of patients and in 61% at follow-up. RV dilation was common at follow-up, especially in the presence of severe conduit regurgitation.

A Deep Dive Into Retroesophageal Major Aortopulmonary Collateral Arteries

Background: The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. The purpose of this paper was to review the anatomy, physiology, and surgical characteristics of retroesophageal MAPCAs. Methods: This manuscript summarizes the data from a series of three papers that have focused on the subject of retroesophageal MAPCAs from our institution over the past ten years. Results: Two-thirds of patients evaluated had a retroesophageal MAPCA identified at surgery. Retroesophageal major aortopulmonary collateral arteries (REMs) were more common with a left arch (77%) compared with a right arch (53%). Of all REMs evaluated, 83% were single supply, 13% were dual supply with an inadequate connection, and 4% were dual supply with an adequate connection. Based on these findings, 96% of retroesophageal MAPCAs were unifocalized. Follow-up catheterization was performed at a median of 17 months after surgery; 75% of unifocalized MAPCAs were widely patent, 20% were patent but stenotic, and 5% were occluded. Conclusions: The data demonstrate that retroesophageal MAPCAs are relatively common and almost always require unifocalization. At mid-term follow-up, 95% of unifocalized MAPCAs were found to be patent.

The development and efficacy of a paediatric cardiology fellowship online preparatory course

BACKGROUND

The transition from residency to paediatric cardiology fellowship is challenging due to the new knowledge and technical skills required. Online learning can be an effective didactic modality that can be widely accessed by trainees. We sought to evaluate the effectiveness of a paediatric cardiology Fellowship Online Preparatory Course prior to the start of fellowship.

METHODS

The Online Preparatory Course contained 18 online learning modules covering basic concepts in anatomy, auscultation, echocardiography, catheterisation, cardiovascular intensive care, electrophysiology, pulmonary hypertension, heart failure, and cardiac surgery. Each online learning module included an instructional video with pre-and post-video tests. Participants completed pre- and post-Online Preparatory Course knowledge-based exams and surveys. Pre- and post-Online Preparatory Course survey and knowledge-based examination results were compared via Wilcoxon sign and paired t-tests.

RESULTS

151 incoming paediatric cardiology fellows from programmes across the USA participated in the 3 months prior to starting fellowship training between 2017 and 2019. There was significant improvement between pre- and post-video test scores for all 18 online learning modules. There was also significant improvement between pre- and post-Online Preparatory Course exam scores (PRE 43.6 ± 11% versus POST 60.3 ± 10%, p < 0.001). Comparing pre- and post-Online Preparatory Course surveys, there was a statistically significant improvement in the participants' comfort level in 35 of 36 (97%) assessment areas. Nearly all participants (98%) agreed or strongly agreed that the Online Preparatory Course was a valuable learning experience and helped alleviate some anxieties (77% agreed or strongly agreed) related to starting fellowship.

CONCLUSION

An Online Preparatory Course prior to starting fellowship can provide a foundation of knowledge, decrease anxiety, and serve as an effective educational springboard for paediatric cardiology fellows.

20-Year Experience With Repair of Pulmonary Atresia or Stenosis and Major Aortopulmonary Collateral Arteries

BACKGROUND

We have followed a consistent, albeit evolving, strategy for the management of patients with pulmonary atresia or severe stenosis and major aortopulmonary collateral arteries (MAPCAs) that aims to achieve complete repair with low right ventricular pressure by completely incorporating blood supply and relieving stenoses to all lung segments.

OBJECTIVES

The purpose of this study was to characterize our 20-year institutional experience managing patients with MAPCAs.

METHODS

We reviewed all patients who underwent surgery for MAPCAs and biventricular heart disease from November 2001 through December 2021.

RESULTS

During the study period, 780 unique patients underwent surgery. The number of new patients undergoing surgery annually was relatively steady during the first 15 years, then increased substantially thereafter. Surgery before referral had been performed in almost 40% of patients, more often in our recent experience than earlier. Complete repair was achieved in 704 patients (90%), 521 (67%) during the first surgery at our center, with a median right ventricular to aortic pressure ratio of 0.34 (25th, 75th percentiles: 0.28, 0.40). The cumulative incidence of mortality was 15% (95% CI: 12%-19%) at 10 years, with no difference according to era of surgery (P = 0.53). On multivariable Cox regression, Alagille syndrome (HR: 2.8; 95% CI: 1.4-5.7; P = 0.004), preoperative respiratory support (HR: 2.0; 95% CI: 1.2-3.3; P = 0.008), and palliative first surgery at our center (HR: 3.5; 95% CI: 2.3-5.4; P < 0.001) were associated with higher risk of death.

CONCLUSIONS

In a growing pulmonary artery reconstruction program, with increasing volumes and an expanding population of patients who underwent prior surgery, outcomes of patients with pulmonary atresia or stenosis and MAPCAs have continued to improve.

Short- and Mid-Term Results of Pulmonary Valve Replacement with the Inspiris Valve

BACKGROUND

Various bioprosthetic valves are used off-label for pulmonary valve replacement (PVR), but there is no consensus on whether a particular valve is best for this application. Recently, the Inspiris Resilia valve (Edwards Lifesciences Inc) was approved for aortic valve replacement, and surgeons have begun using it for PVR. There is limited evidence on the performance of the Inspiris valve compared with other valves in the pulmonary position.

METHODS

This study reviewed all patients who underwent PVR with a size 19- to 29-mm Inspiris valve or Mosaic valve (Medtronic Inc) from 2007 to 2022 at Lucile Packard Children's Hospital Stanford (Palo Alto, CA). Midterm outcomes included freedom from moderate or severe pulmonary regurgitation (PR), a maximum Doppler gradient ≥36 mm Hg, and freedom from reintervention.

RESULTS

A total of 225 consecutive patients who underwent PVR with a size 19- to 29-mm Mosaic (n = 163) or Inspiris (n = 62) valve were included. There was no difference in baseline characteristics. Early postoperative gradients were low in both groups but higher in the Mosaic cohort, and neither group had more than mild PR on discharge. On univariable and multivariable analysis, Inspiris valves were significantly more likely to develop moderate or greater PR over time. There was no significant difference between the valves in freedom from reintervention or from a maximum gradient ≥36 mm Hg.

CONCLUSIONS

Early and short-term gradients were similar in patients undergoing PVR with Inspiris and Mosaic valves, but significant PR was more common in patients who received an Inspiris valve. These preliminary findings suggest that the durability of the Inspiris valve in the pulmonary position may not be superior to that of other bioprosthetic valves used for PVR.

Outcomes After Development of Ventricular Arrhythmias in Single Ventricular Heart Disease Patients With Fontan Palliation

BACKGROUND

With the advent of more intensive rhythm monitoring strategies, ventricular arrhythmias (VAs) are increasingly detected in Fontan patients. However, the prognostic implications of VA are poorly understood. We assessed the incidence of VA in Fontan patients and the implications on transplant-free survival.

METHODS

Medical records of Fontan patients seen at a single center between 2002 and 2019 were reviewed to identify post-Fontan VA (nonsustained ventricular tachycardia >4 beats or sustained >30 seconds). Patients with preFontan VA were excluded. Hemodynamically unstable VA was defined as malignant VA. The primary outcome was death or heart transplantation. Death with censoring at transplant was a secondary outcome.

RESULTS

Of 431 Fontan patients, transplant-free survival was 82% at 15 years post-Fontan with 64 (15%) meeting primary outcome of either death (n=16, 3.7%), at a median 4.6 (0.4-10.2) years post-Fontan, or transplant (n=48, 11%), at a median of 11.1 (5.9-16.2) years post-Fontan. Forty-eight (11%) patients were diagnosed with VA (90% nonsustained ventricular tachycardia, 10% sustained ventricular tachycardia). Malignant VA (n=9, 2.0%) was associated with younger age, worse systolic function, and valvular regurgitation. Risk for VA increased with time from Fontan, 2.4% at 10 years to 19% at 20 years. History of Stage 1 surgery with right ventricular to pulmonary artery conduit and older age at Fontan were significant risk factors for VA. VA was strongly associated with an increased risk of transplant or death (HR, 9.2 [95% CI, 4.5-18.7]; P<0.001), with a transplant-free survival of 48% at 5-year post-VA diagnosis.

CONCLUSIONS

Ventricular arrhythmias occurred in 11% of Fontan patients and was highly associated with transplant or death, with a transplant-free survival of <50% at 5-year post-VA diagnosis. Risk factors for VA included older age at Fontan and history of right ventricular to pulmonary artery conduit. A diagnosis of VA in Fontan patients should prompt increased clinical surveillance.

Surgical repair of peripheral pulmonary artery stenosis: A 2-decade experience with 145 patients

BACKGROUND

Peripheral pulmonary artery stenosis (PPAS) is a relatively rare form of congenital heart disease often associated with Williams syndrome, Alagille syndrome, and elastin arteriopathy. This disease is characterized by stenoses at nearly all lobar and segmental ostia and results in systemic-level right ventricular pressures. The current study summarizes our experience with the surgical treatment of PPAS.

METHODS

This was a retrospective review of 145 patients who underwent surgical repair of PPAS. This included 43 patients with Williams syndrome, 39 with Alagille syndrome, and 21 with elastin arteriopathy. Other diagnoses include tetralogy of Fallot with PPAS (n = 21), truncus arteriosus (n = 5), transposition (n = 3), double-outlet right ventricle (n = 2), arterial tortuosity syndrome (n = 3), and other (n = 8).

RESULTS

The median preoperative right ventricle to aortic peak systolic pressure ratio was 1.01 (range, 0.50-1.60) which was reduced to 0.30 (range, 0.17-0.60) postoperatively. The median number of ostial repairs was 17 (range, 6-34) and median duration of cardiopulmonary bypass was 398 minutes (range, 92-844). There were 3 in-hospital deaths (2.1%). The median duration of follow-up was 26 months (range, 1-220) with 4 late deaths (2.9%). Eighty-two patients have subsequently undergone catheterization and 74 had a pressure ratio <0.50.

CONCLUSIONS

The surgical treatment of PPAS resulted in a 70% reduction in right ventricular pressures. At 3 years, freedom from death was 94% and 90% of those evaluated maintained low pressures. These results suggest that the surgical treatment of PPAS is highly effective in most patients.

Serial Lung Perfusion Scintigraphy After Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

Background

In patients with tetralogy of Fallot and major aortopulmonary collaterals (MAPCAs), pulmonary blood supply is highly variable. Our approach to this condition emphasizes complete unifocalization of the pulmonary circulation, incorporating all lung segments and addressing stenoses out to the segmental level. Post-repair, we recommend serial lung perfusion scintigraphy (LPS) to assess short-term changes in pulmonary blood flow distribution.

Methods

We reviewed post-discharge and follow-up LPS performed through three years post-repair and analyzed serial changes in perfusion, risk factors for change, and the relationship between LPS parameters and pulmonary artery reintervention.

Results

Of 543 patients who had postoperative LPS results in our system, 317 (58%) had only a predischarge LPS available for review, while 226 had 1 (20%) or more (22%) follow-up scans within three years. Overall, pulmonary flow distribution prior to discharge was balanced, and there was minimal change over time; however, there was considerable patient-to-patient variation in both metrics. On multivariable mixed modeling, time after repair ( P = .025), initial anatomy consisting of a ductus arteriosus to one lung ( P < .001), and age at repair ( P = .014) were associated with changes on serial LPS. Patients who had follow-up LPS were more likely to undergo pulmonary artery reintervention, but within that cohort, LPS parameters were not associated with reintervention risk.

Conclusion

Serial LPS during the first year after MAPCAs repair is a noninvasive method of screening for significant post-repair pulmonary artery stenosis that occurs in a small but important minority of patients. In patients who received follow-up LPS beyond the perioperative period, there was minimal change over time in the population overall, but large changes in some patients and considerable variability. There was no statistical association between LPS findings and pulmonary artery reintervention.

Analysis of Risk Factors Associated with Extracorporeal Membrane Oxygenation After Surgical Repair of Peripheral Pulmonary Artery Stenoses

Objective

Acute lung injury is a known complication of pulmonary artery reconstruction for peripheral pulmonary artery stenosis. Severe cases may require support with extracorporeal membrane oxygenation. The purpose of this study was to evaluate the characteristics of patients requiring extracorporeal membrane oxygenation after pulmonary artery reconstruction.

Methods

This was a retrospective study of 150 patients who underwent surgical repair of peripheral pulmonary artery stenosis at our institution from 2002 to 2022. Underlying diagnoses included Williams syndrome (n = 44), Alagille syndrome (n = 43), elastin arteriopathy (n = 21), tetralogy of Fallot (n = 21), and other (n = 21). Characteristics of patients who required extracorporeal membrane oxygenation were compared with those who did not require extracorporeal membrane oxygenation.

Results

Eleven of the 150 patients undergoing pulmonary artery reconstruction (7.3%) required postoperative extracorporeal membrane oxygenation support (10 for acute lung injury and 1 for cardiac insufficiency). Four patients receiving extracorporeal membrane oxygenation had Williams syndrome, 3 patients had Alagille, and 4 patients had tetralogy of Fallot. Patients requiring extracorporeal membrane oxygenation had a higher preoperative right ventricle to aortic peak systolic pressure ratios (mean 1.14 vs 0.95), greater number of pulmonary artery ostial interventions (median, 23 vs 17), and longer duration of cardiopulmonary bypass (median, 597 vs 400 minutes). There were 3 in-hospital deaths (2.0%), 2 of whom required postoperative extracorporeal membrane oxygenation support.

Conclusions

The data demonstrate multiple differences between patients who did and did not require extracorporeal membrane oxygenation after surgical repair of peripheral pulmonary artery stenosis. These results suggest that the preoperative extent of disease may predispose to the development of acute lung injury requiring extracorporeal membrane oxygenation support.

Impact of liver dysfunction on outcomes in children with Alagille syndrome undergoing congenital heart surgery

OBJECTIVES

Children with Alagille syndrome often have complex forms of congenital heart defects with the majority having peripheral pulmonary artery stenosis (PPAS) and pulmonary valve atresia (PA) or pulmonary valve stenosis. Children with Alagille syndrome also have variable amounts of liver dysfunction. The purpose of this study was to evaluate the impact of liver dysfunction on outcomes in children with Alagille syndrome undergoing congenital heart surgery.

METHODS

This was a retrospective review of 69 patients with Alagille syndrome who underwent congenital heart surgery at our institution. The underlying diagnoses included PPAS (n = 29), tetralogy of Fallot with PPAS (n = 14), tetralogy with PA (n = 3), PA with ventricular septal defect and major aortopulmonary collateral arteries (n = 21) and one each with D-transposition and supravalvar aortic stenosis.

RESULTS

The median age at surgery was 16 months (range 0-228 months). Procedures performed included PPAS repair (n = 43), tetralogy with PA repair (n = 3), unifocalization procedures (n = 21) and other (n = 2). Forty-two (61%) patients had mild or no liver dysfunction, while 26 (38%) had moderate or severe liver dysfunction. The median cardiopulmonary bypass time was 345 min (341 with liver dysfunction, 345 without liver dysfunction). There were a total of 8 operative (12%) deaths and 3 late (4%) deaths. Six operative and 2 late deaths occurred in patients with liver dysfunction (combined 30.7%) versus 2 operative and 1 late death (combined 7.1%) for patients without liver dysfunction (P < 0.05).

CONCLUSIONS

These results suggest that liver dysfunction has a profound impact on survival in children with Alagille syndrome undergoing congenital heart surgery.

Proton magnetic resonance spectroscopy assessment of neonatal brain metabolism during cardiopulmonary bypass surgery

Here, we report on the development and performance of a robust 3-T single-voxel proton magnetic resonance spectroscopy (¹ H MRS) experimental protocol and data analysis pipeline for quantifying brain metabolism during cardiopulmonary bypass (CPB) surgery in a neonatal porcine model, with the overall goal of elucidating primary mechanisms of brain injury associated with these procedures. The specific aims were to assess which metabolic processes can be reliably interrogated by ¹ H MRS on a 3-T clinical scanner and to provide an initial assessment of brain metabolism during deep hypothermia cardiac arrest (DHCA) surgery and recovery. Fourteen neonatal pigs underwent CPB surgery while placed in a 3-T MRI scanner for 18, 28, and 37°C DHCA studies under hyperglycemic, euglycemic, and hypoglycemic conditions. Total imaging times, including baseline measurements, circulatory arrest (CA), and recovery averaged 3 h/animal, during which 30-40 single-voxel ¹ H MRS spectra (sLASER pulse sequence, TR/TE = 2000/30 ms, 64 or 128 averages) were acquired from a 2.2-cc right midbrain voxel. ¹ H MRS at 3 T was able to reliably quantify (1) anaerobic metabolism via depletion of brain glucose and the associated build-up of lactate during CA, (2) phosphocreatine (PCr) to creatine (Cr) conversion during CA and subsequent recovery upon reperfusion, (3) a robust increase in the glutamine-to-glutamate (Gln/Glu) ratio during the post-CA recovery period, and (4) a broadening of the water peak during CA. In vivo ¹ H MRS at 3 T can reliably quantify subtle metabolic brain changes previously deemed challenging to interrogate, including brain glucose concentrations even under hypoglycemic conditions, ATP usage via the conversion of PCr to Cr, and differential changes in Glu and Gln. Observed metabolic changes during CPB surgery of a neonatal porcine model provide new insights into possible mechanisms for prevention of neuronal injury.

The number of postoperative surgical or diagnostic procedures following congenital heart surgery correlates with both mortality and hospital length of stay

BACKGROUND

Outcomes for congenital heart disease have dramatically improved over the past several decades. However, there are patients who encounter intraoperative or postoperative complications and ultimately do not survive. It was our hypothesis that the number of postoperative procedures (including surgical and unplanned diagnostic procedures) would correlate with hospital length of stay and operative mortality.

METHODS

This was a retrospective review of 938 consecutive patients undergoing congenital heart surgery at a single institution over a 2-year timeframe. The number of postoperative surgical and unplanned diagnostic procedures were counted and the impact on hospital length of stay and mortality was assessed.

RESULTS

581 of the 938 (62%) patients had zero postoperative diagnostic or surgical procedures. These patients had a median length of stay of 6 days with a single operative mortality (0.2%). 357 of the 938 (38%) patients had one or more postoperative diagnostic or surgical procedures. These patients had a total of 1586 postoperative procedures. There was a significant correlation between the number of postoperative procedures and both hospital length of stay and mortality (p < .001). Patients who required 10 or more postoperative procedures had a median hospital length of stay of 89 days and had a 50% mortality. There were no survivors in patients who had 15 or more postoperative procedures.

CONCLUSIONS

The data demonstrate that the number of postoperative procedures was highly correlated with both hospital length of stay and mortality.

Surgical Repair of Supravalvar Aortic Stenosis in Association With Transverse and Proximal Descending Aortic Abnormalities

BACKGROUND

Supravalvar aortic stenosis (SVAS) may be an isolated defect of the proximal ascending aorta. However, more severe cases have extension of the arteriopathy into the transverse and proximal descending aorta. The purpose of this study was to review our experience with SVAS with and without aortic arch arteriopathy.

METHODS

This was a retrospective review of 58 patients who underwent surgical repair of SVAS. The median age at repair was 18 months. A total of 37 patients had Williams syndrome. A total of 31 (53%) patients had associated peripheral pulmonary artery stenosis and 23 (39%) had coronary artery ostial stenosis (CAOS).

RESULTS

A total of 37 of 58 (64%) patients had surgical repair of SVAS without the need for arch intervention while 21 (36%) patients had repair of the distal aortic arch. There were 3 (5.2%) operative deaths, 2 of whom had aortic arch involvement and one without arch involvement. There were 2 deaths after discharge from the hospital. Patients who needed arch surgery were more likely to have severe arch gradients compared to those without arch involvement (71% vs 30%, P < .05), were more likely to undergo concomitant procedures for peripheral pulmonary artery stenosis or CAOS (90% vs 62%, P < .05), and to have Williams syndrome (86% vs 51%, P < .05).

CONCLUSIONS

More than one-third of patients who had SVAS repair at our institution had procedures directed at the transverse or proximal descending aorta. Patients with arch involvement had more severe arch obstruction, required more concomitant procedures, and were more likely to have Williams syndrome.

Mortality Prediction Following Cardiac Surgery in Children - An STS Congenital Heart Surgery Database Analysis

BACKGROUND

The Society of Thoracic Surgeons' Congenital Heart Surgery Database (STS CHSD) provides risk-adjusted operative mortality rates to approximately 120 North American congenital heart centers. Optimal case-mix adjustment methods for operative mortality risk prediction in this population remain unclear.

METHODS

A panel created diagnosis-procedure (D-P) combinations of encounters in the CHSD. Models for operative mortality using the new D-P categories, procedure-specific risk factors, and syndromes/abnormalities included in the CHSD were estimated using Bayesian additive regression trees (BART) and lasso models. Performance of the new models was compared to the current STS-CHSD risk model.

RESULTS

Of 98,825 operative encounters (69,063 training; 29,762 testing), 2,818 (2.85%) STS-defined operative mortalities were observed. Differences in sensitivity, specificity, true and false positive predicted values were negligible across models. Calibration for mortality predictions at the higher end of risk from the lasso and BART models was better than predictions from the STS-CHSD model, likely due to new models' inclusion of diagnosis-palliative procedure variables affecting < 1% of patients overall, but accounting for 27% of mortalities. Model discrimination varied across models for high-risk procedures, hospital volume, and hospitals.

CONCLUSIONS

Overall performance of the new models did not differ meaningfully from the STS-CHSD risk model. Addition of procedure-specific risk factors and allowing diagnosis to modify predicted risk for palliative operations may augment model performance for very high-risk surgeries. Given the importance of risk adjustment in estimating hospital quality, a comparative assessment of surgical program quality evaluations using the different models is warranted.

Relation Between Pulmonary Artery Pressures Measured Intraoperatively and at One-Year Catheterization After Unifocalization and Repair of Tetralogy with Major Aortopulmonary Collateral Arteries

To assess the relationships between pulmonary artery (PA) pressure and the PA:aortic systolic pressure ratio measured intraoperatively and at surveillance catheterization in patients achieving complete unifocalization and repair for tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs). This was a single-center retrospective cohort analysis of all patients who underwent complete repair of TOF/MAPCAs from 2002-2019 and received a postoperative surveillance catheterization at our center 6-24 months after surgery. Associations between intraoperative and catheter hemodynamic data were analyzed. 163 patients were included. Median systolic PA pressure was 30 (quartiles 26, 35) and 35 (28, 42) mmHg intraoperatively and at catherization respectively; systolic aortic pressure 90 (86, 100) and 84 (76, 92); and PA:aortic pressure ratio was 0.33 (0.28, 0.40) and 0.41 (0.34, 0.49). Moderate correlation was found between the intraoperative and catheter-based hemodynamics, with the majority of systolic PA pressures within 10mmHg and PA:Ao systolic ratios within 0.1. Changes in the ratio were influenced to a similar degree by differences in PA and aortic pressures. Surgical and/or catheter reinterventions were more common in patients with both higher intraoperative PA systolic pressure and PA:aortic systolic ratios and in those with greater discrepancy between intraoperative and catheterization values. PA systolic pressure and the PA:aortic systolic pressure ratio measured immediately after repair remain useful metrics for assessing the initial operative PA reconstruction, and as indicators of longer term hemodynamics. Initially elevated and subsequently discrepant PA systolic pressure and PA:aortic systolic pressure ratios were associated with higher rates of reintervention. (Figure 7).

Comprehensive diagnostic catheterization in children with major aortopulmonary collateral arteries: A review of catheterization technique and anatomic nomenclature

Achieving an optimal surgical result in patients with major aortopulmonary collateral arteries (MAPCAs) requires a thorough preoperative evaluation of the anatomy and physiology of the pulmonary circulation. This review provides a detailed description of diagnostic catheterization in patients with MAPCAs, including a summary of catheterization techniques, an overview of commonly used terms, and a review of MAPCA and pulmonary artery angiographic anatomy.

Midterm fate of unifocalized major aortopulmonary collateral arteries in patients with retroesophageal major aortopulmonary collateral arteries

BACKGROUND

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (MAPCAs) is a relatively rare and complex form of congenital heart disease. Unifocalization of MAPCAs has been advocated by some groups for the treatment of this condition. The purpose of this study was to assess the midterm fate of unifocalized MAPCAs in a cohort of patients with retroesophageal MAPCAs.

METHODS

This was a retrospective review of 37 patients who underwent a unifocalization procedure. All patients in this study had 1 or more retroesophageal MAPCAs, and detailed mapping of the MAPCAs was made based on a combination of the cardiac catheterization and surgical findings.

RESULTS

The 37 patients had a total of 166 MAPCAs, or 4.5 MAPCAs per patient. One hundred twenty-nine (78%) MAPCAs were unifocalized, whereas 37 (22%) were ligated because they were dual supply. Median follow-up was 69 months. At follow-up cardiac catheterization, evaluation of the 129 unifocalized MAPCAs demonstrated that 123 (95%) had antegrade flow, whereas 6 were occluded. For the 123 MAPCAs with antegrade flow, 97 (80%) were widely patent, whereas 26 were stenotic. Thirteen of the 37 patients have subsequently undergone reintervention on MAPCAs that were determined to be stenotic following unifocalization. Seven of these patients had mild disease and had complete resolution with balloon (n = 5) or surgical revision (n = 2). Six patients with moderate or severe disease underwent surgical revision with confirmed resolution in 4 of 6.

CONCLUSIONS

The data demonstrate that the majority of unifocalized MAPCAs remain widely patent following unifocalization. However, one-quarter of unifocalized MAPCAs develop stenoses or occlusion. These results suggest the fate for most unifocalized MAPCAs is favorable but highlight the need for close vigilance.

Cor Triatriatum in Association With a Unique Form of Partial Anomalous Pulmonary Venous Connection

Cor triatriatum may be associated with abnormalities of pulmonary venous anatomy. This case report describes a unique form of partial anomalous pulmonary venous connection. The patient presented at 5 weeks of age with symptoms of tachypnea and poor feeding. Echocardiography demonstrated cor triatriatum and partial anomalous pulmonary venous drainage of the right upper lung. The patient underwent urgent repair of cor triatriatum. It was elected to not address the partial anomalous pulmonary venous connection at that time. The patient returned at age 19 months for elective repair of the anomalous pulmonary venous connection. There was also a large vein connecting the right lower pulmonary veins to the superior vena cava. This was repaired by dividing the superior vena cava along a vertical axis to redirect the flow of the anomalous pulmonary veins through the connecting vein to the left atrium. This report describes the anatomy and surgical approach to a unique form of anomalous pulmonary venous connection.

Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC  ≤ 35% and TAPSE Z-score  ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Durability of Pulmonary Valve Replacement with Large Diameter Stented Porcine Bioprostheses

There is limited information about durability of large diameter porcine bioprostheses implanted for pulmonary valve replacement (PVR). We studied patients who underwent surgical PVR from 2002-2019 with a stented porcine bioprosthetic valve (BPV) with a labeled size ≥27 mm. The primary outcome was freedom from reintervention. During the study period, 203 patients underwent PVR using a porcine BPV ≥27 mm, 94% of whom received a Mosaic valve (Medtronic Inc., Minneapolis, MN). Twenty patients underwent reintervention from 3.4-12.0 years after PVR: 5 surgical and 15 transcatheter PVR procedures. The indication for reintervention was regurgitation in 13 patients, stenosis in 2, mixed disease in 4, and endocarditis in 1. Estimated freedom from reintervention was 97±1% at 5 years and 82±4% at 10 years, and freedom from prosthesis dysfunction (moderate or severe regurgitation and/or a maximum Doppler gradient ≥50 mm Hg) over time was 91±2% at 5 years and 74±4% at 10 years. Younger age and smaller true valve diameter were associated with shorter freedom from reintervention, but valve oversizing was not. The durability of large stented porcine bioprostheses in the pulmonary position is generally excellent, particularly in adolescents and adults, similar to various other types of BPV. In the current study, relative valve size was not associated with valve longevity, although the low event-rate in this population was a limiting factor.

Balloon Angioplasty for Pulmonary Artery Stenosis After Complete Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

OBJECTIVES

The objective of this study was to assess procedural outcomes of balloon pulmonary artery (PA) angioplasty procedures after complete repair of tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs).

BACKGROUND

Our approach to patients with TOF/MAPCAs emphasizes early complete unifocalization and repair. Major PA reinterventions are relatively uncommon. Balloon PA angioplasty is often used, but the effectiveness of balloon PA angioplasty in this population is unknown.

METHODS

The study cohort comprised patients who underwent complete unifocalization and repair of TOF/ MAPCAs at our center between 2002-2018 and underwent balloon PA angioplasty after repair. To assess immediate procedural outcomes, pre- and postintervention PA measurements were compared.

RESULTS

We reviewed 134 vessels that were dilated a median of 1.1 years after repair in 60 patients (median 2 PA branches per patient). Treated vessels included 15 central, 64 lobar, and 55 segmental branches. The median PA diameter at the level of stenosis increased from 1.9 mm to 3.3 mm (P<.001), and the median diameter increase was 50%. All but 6 treated vessels were enlarged. The stenosis-distal diameter ratio increased from a median of 64% to 89% (P<.001). The median central PA to aortic systolic pressure ratio was 47% before and 39% after intervention (P<.001).

CONCLUSIONS

Balloon PA angioplasty was acutely effective at treating most stenoses of reconstructed PA branches after repair of TOF/MAPCAs. Simple angioplasty can be a useful tool in treating isolated or modest stenoses after unifocalization/PA reconstruction surgery using our approach.

Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study

BACKGROUND

Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation.

METHODS

We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure.

RESULTS

Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m² during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair.

CONCLUSIONS

The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.

To Unifocalize or Not to Unifocalize?: A Comparison of Retroesophageal Versus Anterior Collaterals

BACKGROUND

The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. This study compared the physiologic and surgical characteristics of retroesophageal vs anterior located MAPCAs.

METHODS

This was a retrospective review of 42 patients who had 1 (n = 36) or 2 (n = 6) retroesophageal MAPCAs. These MAPCAs were then characterized as (1) single supply, meaning no connection to the pulmonary arteries; (2) dual supply, but inadequate connection to the distal pulmonary vascular bed; and (3) dual supply with adequate connection.

RESULTS

The 42 patients presented with 187 MAPCAs, or 4.5 MAPCAs per patient. Of these, 48 MAPCAs were retroesophageal, including 40 that were single supply, 6 were dual supply with inadequate connection, and 2 had dual supply with adequate connection. On the basis of this anatomy and physiology, 96% of retroesophageal MAPCAs were unifocalized. For the 139 anterior MAPCAs, 89 were single supply, 15 were dual supply with inadequate connection, and 35 were dual supply with adequate connection; thus, 75% of anterior MAPCAs were unifocalized (P < .01 compared with retroesophageal MAPCAs).

CONCLUSIONS

The data demonstrate that retroesophageal MAPCAs had very different anatomy and physiology compared with anterior MAPCAs. These results suggest that nearly every retroesophageal MAPCA should be unifocalized to incorporate the lung segments supplied.

Longevity of Large Aortic Allograft Conduits in Tetralogy With Major Aortopulmonary Collaterals

BACKGROUND

Appropriate conduit selection for right ventricle (RV)-to-pulmonary artery (PA) connection has been extensively studied, with older implantation age, pulmonary (vs aortic) homografts, and true sizing associated with increased longevity. Notably, patients with PA arborization abnormalities (ie, major aortopulmonary collateral arteries [MAPCAs]) are reported to require earlier and more frequent conduit interventions. We aim to understand the behavior of large-diameter aortic homografts in patients with MAPCAs, which are programmatically utilized at our institution.

METHODS

This is a single-center retrospective cohort study including all children less than 12 years of age who underwent RV-PA connection using an aortic homograft greater than or equal to 16 mm diameter between 2002 and 2019, with a primary outcome of freedom from any RV-PA reintervention and a secondary outcome of freedom from surgical reintervention. Patients were grouped by absolute and indexed conduit sizes for further analysis.

RESULTS

A total of 336 conduits were followed for a median of 3.0 years; transcatheter (n = 30) or surgical (n = 35) reintervention was performed on 64 conduits. Estimated freedom from reintervention and surgical replacement was 84% and 90% at 5 years. Younger age and smaller absolute conduit size were associated with earlier reintervention, but conduit Z-score (median 3.5) was not associated with outcome.

CONCLUSIONS

The programmatic use of oversized aortic homograft RV-PA conduits in the surgical repair of MAPCAs provides a focused experience that demonstrates similar longevity to reported best alternatives. Secondarily, conduit oversizing may improve durability and enables an increased likelihood of nonoperative reintervention.

Outcomes in Patients with Alagille Syndrome and Complex Pulmonary Artery Disease

OBJECTIVE

To assess outcomes in a large cohort of patients with Alagille syndrome (ALGS) who underwent pulmonary artery reconstruction surgery for complex pulmonary artery disease.

STUDY DESIGN

Patients with ALGS who underwent pulmonary artery reconstruction surgery at Lucile Packard Children's Hospital Stanford were reviewed. Patients were examined as an overall cohort and based on the primary cardiovascular diagnosis: severe isolated branch pulmonary artery stenosis, tetralogy of Fallot (TOF) without major aortopulmonary collateral arteries (MAPCAs), or TOF with MAPCAs.

RESULTS

Fifty-one patients with ALGS underwent pulmonary artery surgery at our center, including 22 with severe branch pulmonary artery stenosis, 9 with TOF without MAPCAs, and 20 with TOF and MAPCAs. Forty-one patients (80%) achieved a complete repair. Five of the patients with TOF with MAPCAs (25%) underwent complete repair at the first surgery, compared with 8 (89%) with TOF without MAPCAs and 19 (86%) with isolated branch pulmonary artery stenosis. At a median follow-up of 1.7 years after the first surgery, 39 patients (76%) were alive, 36 with a complete repair and a median pulmonary artery:aortic systolic pressure of 0.38. Nine patients (18%), including 8 with isolated branch pulmonary artery stenosis, underwent liver transplantation.

CONCLUSIONS

Most patients with ALGS and complex pulmonary artery disease can undergo complete repair with low postoperative right ventricular pressure. Patients with TOF/MAPCAs had the worst outcomes, with higher mortality and more frequent pulmonary artery interventions compared with patients with TOF without MAPCAs or isolated branch pulmonary artery stenosis. Complex pulmonary artery disease is not a contraindication to liver transplantation in patients with ALGS.

Transfusion Outcomes in Patients Undergoing Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

BACKGROUND

Surgical repair of tetralogy of Fallot and major aortopulmonary collaterals (TOF/MAPCAs) involves unifocalization of MAPCAs and reconstruction of the pulmonary arterial circulation. Surgical and cardiopulmonary bypass (CPB) times are long and suture lines are extensive. Maintaining patency of the newly anastomosed vessels while achieving hemostasis is important, and assessment of transfusion practices is critical to successful outcomes.

METHODS

Clinical, surgical, and transfusion data in patients with TOF/MAPCAs repaired at our institution (2013-2018) were reviewed. Types and volumes of blood products used in the perioperative period, in addition to the use of antifibrinolytics and/or procoagulants (factor VIII inhibitor bypassing activity [FEIBA]; anti-inhibitor coagulant complex), were assessed. Outcome measures included days on mechanical ventilation (DOMV), postoperative intensive care unit and hospital length of stay (LoS), and incidence of thrombosis.

RESULTS

Perioperative transfusion data from 279 patients were analyzed. Surgical (879 ± 175 minutes vs 684 ± 257 minutes) and CPB times (376 ± 124 minutes vs 234 ± 122 minutes) were longer in patients who received FEIBA than those who did not. Although the indexed volume of packed red blood cells (128.4 ± 82.2 mL/kg) and fresh frozen plasma (64.2 ± 41.1 mL/kg) was similar in patients who did and did not receive FEIBA, the amounts of cryoprecipitate (5.5 ± 5.2 mL/kg vs 5.8 ± 4.8 mL/kg) and platelets (19.5 ± 20.7 mL/kg vs 20.8 ± 13 mL/kg) transfused were more in those who did receive FEIBA.

CONCLUSION

Perioperative transfusion is an important component in the overall surgical and anesthetic management of patients with TOF/MAPCAs. The intraoperative use of FEIBA was not associated with a decrease in the amount of blood products transfused, DOMV, or LoS or with an increase in thrombotic complications.

Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot

Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross-sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross-sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.

Prevalence of Complications Following Unifocalization and Pulmonary Artery Reconstruction Procedures

Background:

Unifocalization and pulmonary artery reconstructions have been developed to treat complex disorders of pulmonary artery development. These procedures require extremely long periods of cardiopulmonary bypass (CPB) to facilitate surgical repair. The objective of this study was to document the prevalence of complications in patients undergoing unifocalization or pulmonary artery reconstructions associated with prolonged periods of CPB.

Methods:

This was a retrospective review of 100 consecutive patients who underwent unifocalization (n = 66) or pulmonary artery reconstructions (n = 34) with CPB times in excess of five hours. Thirty-eight of these operations were primary procedures, whereas 62 were reoperations.

Results:

The median age at surgery was 15 months, median duration of CPB was 473 minutes, median number of postoperative complications was 5, and the median length of hospital stay was 24 days. The most frequently encountered complications were low cardiac output (43%), open sternum (40%), reintubation (24%), arrhythmia (17%), and bronchoscopy (17%). There was a correlation between the total number of complications and overall length of hospital stay ( R 2 = 0.64). Major adverse cardiac events (MACE) occurred in 11 patients with one hospital mortality. Patients who experienced MACE had a median length of stay that was 35 days longer (56 vs 21 days) than patients who did not experience MACE.

Conclusions:

The data demonstrate that complications were relatively frequent in this cohort of patients and had a linear association with hospital length of stay. Major adverse cardiac events were encountered at a modest prevalence but had a profound impact on measures of outcome.

Unifocalization and pulmonary artery reconstruction in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery before referral

OBJECTIVE

The study objective was to characterize and analyze outcomes in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who had undergone surgery elsewhere before referral (prereferral surgery).

METHODS

Patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery between 2001 and 2019 at our center were reviewed. Prereferral surgery and unoperated patients were compared, as were subsets of prereferral surgery patients who had undergone different types of prior procedures. Primary outcomes included complete repair with survival to 6 months, death, and perioperative metrics.

RESULTS

Of 576 patients studied, 200 (35%) had undergone a wide range and number of prior operations elsewhere, including 92 who had pulmonary blood supply through a shunt and 108 who had a right ventricle pulmonary artery connection. Patients who underwent prereferral surgery with an existing right ventricle pulmonary artery connection had undergone more prereferral surgery procedures than those with a shunt and were more likely to have a right ventricle outflow tract pseudoaneurysm or pulmonary artery stent (all P < .001) at the time of referral. The cumulative incidences of complete repair and death were similar regardless of prereferral surgery status, but the cumulative incidence of complete repair with 6-month survival was higher (P = .002) and of death lower (P = .18) in patients who had prior right ventricle pulmonary artery connection compared with those who had received a prior shunt only.

CONCLUSIONS

Our comprehensive management strategy for tetralogy of Fallot and major aortopulmonary collateral arteries can be applied with excellent procedural results in both unoperated patients and those who have undergone multiple and varied procedures elsewhere.

Deep Hypothermic Circulatory Arrest Activates Neural Precursor Cells in the Neonatal Brain

BACKGROUND

Use of antegrade cerebral perfusion (ACP) as an alternative neuroprotection strategy to deep hypothermic circulatory arrest (DHCA) in the setting of cardiopulmonary bypass in neonates has become a common approach, although the value of ACP over DHCA remains highly debated. This study investigated the disruption to neonatal brain homeostasis by DHCA and ACP.

METHODS

Neonatal pigs (7 days old) undergoing bypass were assigned to 4 groups: DHCA at 18°C and ACP at 18°, 25°, and 32° for 45 minutes (n = 6 per group). ACP was initiated through the innominate artery and maintained at 40 mL/kg/min. After bypass, all animals were maintained sedated and intubated for 24 hours before being euthanized. Brain subventricular zone tissues were analyzed for histologic injury by assessing apoptosis and neural homeostasis (Nestin).

RESULTS

Histologic examination showed no significant ischemic/hypoxic neuronal death at any cooling temperature among the 4 treatment groups. However, we detected a significantly higher apoptotic rate in DHCA compared with ACP at 18°C (P = .003-.017) or 25°C (P = .012-.043), whereas apoptosis at 32°C was not different from DHCA. Of note, we identified increased Nestin expression in the DHCA group compared with all ACP groups (P range = .011-.041).

CONCLUSIONS

Neonatal piglet ACP at 18° or 25°C provides adequate protection from increased brain cellular apoptosis. In contrast to ACP, however, DHCA induces brain Nestin expression, indicating activation of neural progenitor cells and the potential of altering neonatal neurodevelopmental progression. DHCA has potential to more profoundly disrupt neural homeostasis than does ACP.

Pulmonary Artery Reconstruction After Failed Pulmonary Artery Stents

BACKGROUND

Pulmonary artery stents are widely deployed in patients with stenoses in the branch pulmonary arteries. However, stents do not address more peripheral sites of stenosis and invariably develop in-stent restenosis. The purpose of this study was to review our experience with pulmonary artery reconstruction after failed pulmonary artery stents.

METHODS

This was a retrospective study of 56 patients who underwent pulmonary artery reconstruction after failed pulmonary artery stents. These patients had undergone a median of 2 (range, 0-5) previous surgical procedures and 2 (range, 1-4) pulmonary artery stents.

RESULTS

The median age at stent surgery was 5 (range, 0.3-23.6) years. The majority of stents (79%) were completely removed and patch augmented. The minority of stents (21%) were felt to be unremovable and thus were split longitudinally and reconstructed using a pulmonary artery homograft. There was 1 (1.8%) operative mortality. The mean pulmonary artery-to-aortic pressure ratio decreased from a preoperative value of 0.91 ± 0.21 to a postoperative value of 0.31 ± 0.07 (P < .001). The median hospital length of stay was 10 days. The median duration of follow-up was 1.8 years. There has been no midterm mortality. Six patients have undergone balloon dilation postoperatively for residual pulmonary artery stenosis.

CONCLUSIONS

Pulmonary artery reconstruction resulted in a significant decrease in pulmonary artery-to-aortic pressure ratios. The subsequent need for reintervention on the pulmonary arteries has been relatively low (11% to date). These results suggest that patients with pulmonary artery stents can be successfully treated with surgical reconstruction.

Surgical Repair of Peripheral Pulmonary Artery Stenosis in Patients Without Williams or Alagille Syndromes

Peripheral pulmonary artery stenosis is a relatively rare form of congenital heart disease typically associated with genetic syndromes, such as Williams or Alagille syndromes. However, some patients present with severe stenosis without associated syndromes. The purpose of the study was to review our surgical experience in such patients. This was a retrospective review of 30 patients who underwent surgical repair for peripheral pulmonary artery stenosis. Concomitant anatomical diagnoses in 20 patients (67%) included supravalvar aortic stenosis (n = 8), tetralogy of Fallot (n = 4), d-transposition of the great arteries (n = 2), truncus arteriosus (n = 2), hypoplastic left heart syndrome (n = 2), ventricular septal defect (n = 1), and patent ductus arteriosus (n = 1). Additional medical diagnoses in 15 patients (50%) included elastin arteriopathy (n = 9), pulmonary artery calcinosis (n = 1), arterial tortuosity syndrome (n = 1), DiGeorge syndrome (n = 1), and Noonan syndrome (n = 1). Median age at surgery was 3.6 years (interquartile range 1.6-7.4 years). Seventeen patients (57%) had prior cardiac operations, and 16 patients (53%) previously underwent percutaneous intervention. With surgery, mean right ventricle-to-aortic systolic pressure ratio decreased from 0.95 ± 0.2 to 0.28 ± 0.08 (P< 0.0001). Median duration of cardiopulmonary bypass was 369 minutes. There was 100% survival to hospital discharge, with no mortality at mean follow-up of 2.3 years. No patient required reoperation, while 4 underwent balloon dilation. Freedom from pulmonary artery catheter-based reintervention was 95% and 80% at 12 and 36 months, respectively. Patients with peripheral pulmonary artery stenosis without either Williams or Alagille syndrome can successfully undergo surgical repair with a significant reduction in right ventricle-to-aortic pressure ratios.

Secondary repair of incompetent pulmonary valves after previous surgery or intervention: Patient selection and outcomes

OBJECTIVES

Pulmonary valve (PV) regurgitation (PR) is common after intervention for a hypoplastic right ventricular outflow tract. Secondary PV repair is an alternative to replacement (PVR), but selection criteria are not established. We sought to elucidate preoperative variables associated with successful PV repair and to compare outcomes between repair and PVR.

METHODS

Patients who underwent surgery for secondary PR from 2010 to 2017 by a single surgeon were studied. The PV annulus and leaflets were measured on the preoperative echocardiogram and magnetic resonance images, and the primary predictor variable was leaflet area indexed to ideal PV annulus area (iPLA) by magnetic resonance imaging. PV repair and PVR groups were compared using multivariable logistic regression, and with a conditional inference tree. Freedom from PV dysfunction and from reintervention were assessed with Kaplan-Meier survival analyses.

RESULTS

Of 85 patients, 31 (36%) underwent PV repair. By multivariable analysis, longer PV total leaflet length (cm/m²) (β = 3.00, standard error [SE] = 0.82, P < .001), larger PV z score (β = 1.34, SE = 0.39, P = .001), and larger iPLA (β = 8.13, SE = 2.62, P = .002) were associated with repair. iPLA of 0.90 or greater was 91% sensitive and 83% specific for achieving PV repair. At a median of 4.1 years follow-up, there was greater freedom from significant PR in the PV repair group (log rank P = .008).

CONCLUSIONS

Patients with an iPLA >0.9, and those with an iPLA between 0.7 and 0.9 with a PV annulus z score >0 should be considered for a native PV repair. At midterm follow-up, patients with a PV repair were not more likely to develop PR or to require reintervention when compared with patients undergoing PVR.

Lecompte Procedure for Relief of Severe Airway Compression in Children With Congenital Heart Disease

PURPOSE

Children with congenital heart disease may present with severe airway compression prior to any surgical procedure or may develop airway compression following their surgical procedure. This combination of congenital heart defect and airway compression poses a significant management challenge. The purpose of this study was to review our experience with the Lecompte procedure for relief of severe airway compression.

METHODS

This was a retrospective review of ten patients who underwent a Lecompte procedure for relief of severe airway compression over the past nine years (2010-2018). Three patients with absent pulmonary valve syndrome presented with severe symptoms prior to any surgical procedure. Seven patients presented with symptoms of airway compression following repair of their congenital heart defects (one with absent pulmonary valve syndrome, three patients had repair of pulmonary atresia with ventricular septal defect, and three patients had undergone aortic arch surgery). The median age at presentation was two years (range: one day to seven years).

RESULTS

The ten patients underwent a Lecompte procedure without any significant complications or operative mortality. The median interval between the surgical procedure and extubation was 9.5 days. No patients have required any further interventions for relief of airway obstruction.

CONCLUSIONS

The Lecompte procedure is a surgical option for young children who present with severe airway compression. The patients in this series responded well to the Lecompte procedure as evidenced by clinical relief of airway compression.

Perfusion Methods and Modifications to the Cardiopulmonary Bypass Circuit for Midline Unifocalization Procedures

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is a rare form of congenital heart disease. The midline unifocalization procedure has been developed for the treatment of PA/VSD/MAPCAs. These are complex and very lengthy procedures that require an entirely different method of perfusion. The purpose of this study was to review our perfusion modifications to support these unifocalization procedures. Sixty-four unifocalization procedures have been performed at our institution during the past 3 years. The median age was 4.1 months (range 1 month-3.5 years) and the median weight at surgery was 4.5 kg (range 3.5-19 kg). The median duration of cardiopulmonary bypass was 352 minutes (range 128-629 minutes), and the median duration of cross-clamp was 24 minutes (range 14-72 minutes). The conduct of surgery included cooling to a rectal perfusion temperature of 25° and a flow rate of 100 mL/kg/min. A pH-stat strategy and del Nido cardioplegia were used. Modifications to the cardiopulmonary bypass circuit include upsizing the oxygenator, reservoir, cannulae, vent catheter, and tubing. All circuits were modified to include the capability of performing an intraoperative flow study. This study is used to determine whether the VSD can be closed during surgery. A collateral flow study circuit is also set up for first-time operations to measure the residual collateral flow after all of the MAPCAs have been harvested. Patients who require midline unifocalization will invariably require very lengthy periods of support on cardiopulmonary bypass. We have adapted our perfusion circuitry to prepare for the demands on the bypass circuit to meet the requirements of this patient population. Our institution has developed a systematic approach for the conduct of perfusion to best serve our patients presenting with PA/VSD/MAPCAs.

Surgical treatment of anomalous left main coronary artery with an intraconal course

OBJECTIVE

Anomalous left main coronary artery (LMCA) with an intraconal course is a relatively rare form of anomalous aortic origin of a coronary artery (AAOCA) from the wrong sinus of Valsalva. There is currently a paucity of information regarding this entity. The purpose of this article is to review our surgical experience with repair of anomalous LMCA with an intraconal course.

METHODS

This was a retrospective review of 12 patients with an anomalous LMCA and an intraconal course who underwent surgical repair. The median age at surgery was 15 years (range 2-47). The seven oldest patients all had preoperative symptoms of exertional chest pain and one also had exertional syncope. The five youngest patients had no preoperative symptoms. One of these patients had a hemodynamically significant ventricular septal defect and one patient was the sibling of a patient who had undergone repair of AAOCA.

RESULTS

The 12 patients underwent surgical repair including unroofing of the myocardial bridge overlying the intraconal LMCA and a LeCompte procedure. There was no early or late mortality and there were no significant complications. All 12 patients have resumed normal, unrestricted activities.

CONCLUSIONS

Twelve patients with an anomalous LMCA and intraconal course presented to our institution for treatment. Surgical repair was performed successfully in all 12, with resolution of symptoms in the 7 patients who were symptomatic preoperatively. These results suggest that the surgical treatment is safe and efficacious in patients with an anomalous LMCA and intraconal course.

Assessment of the Reconstructed Pulmonary Circulation With Lung Perfusion Scintigraphy After Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

Background:

Pulmonary vascular supply in tetralogy of Fallot (TOF) with major aortopulmonary collaterals (MAPCAs) is highly variable. Our approach to surgical management of this condition emphasizes early repair including unifocalization and reconstruction of the pulmonary circulation, incorporating all lung segments and addressing stenoses both proximal to and within the lung, in addition to ventricular septal defect closure. At our institution, we have over 15 years of experience using lung perfusion scintigraphy (LPS) to assess the distribution of pulmonary blood flow after complete unifocalization and repair.

Methods:

We reviewed clinical and quantitative LPS data in 310 patients who underwent complete unifocalization and repair of TOF/MAPCAs from 2003 to 2018 at our institution. Postrepair relative lung perfusion distributions were determined from LPS initially obtained at our institution within 60 days after repair and thereafter.

Results:

Total lung perfusion to the right and left lungs was 58.0% ± 14.2% and 42.0% ± 14.2%, respectively. Perfusion was balanced in 75% of patients and unbalanced in 25%, including 11% in whom it was extremely unbalanced. On multivariable analysis, older age at repair, surgery other than a single-stage complete unifocalization, and native anatomy consisting of unilateral pulmonary blood supply through a ductus arteriosus were associated with unbalanced perfusion.

Conclusion:

We present our experience using LPS as an outcome measure after surgical repair of TOF/MAPCAs. Balanced lung perfusion was present in the majority of patients who had complete repair of TOF/MAPCAs performed at our center.

Corrected Transposition: Anatomic Repair Using the Hemi-Mustard Atrial Baffle and Bidirectional Superior Cavopulmonary Connection

Anatomic repair for congenitally corrected transposition requires thoughtful surgical planning at both initial (neonatal or late) presentation, and during definitive repair. An algorithmic approach to the overall management of this lesion, with its many associated intracardiac anomalies, is presented. Modified atrial switch with bidirectional superior cavopulmonary connection is commonly utilized and demonstrates favorable results through a 20-year experience. Herein, technical considerations learned during the implementation of this strategy are described and emphasize the concept, in selected cases, of native pulmonary root preservation by translocation as an adjunct that is uniquely suited by adopting this approach.

Serial assessment of postoperative ventricular mechanics in young children with tetralogy of Fallot: Comparison of transannular patch and valve-sparing repair

BACKGROUND

Little is known about the early time course of biventricular function and mechanics after tetralogy of Fallot (TOF) repair. We sought to evaluate and describe the evolution of the right ventricle (RV) after TOF repair in young infants and children using conventional echocardiographic parameters and global longitudinal strain (GLS).

METHODS

A retrospective review was performed of all patients with TOF and pulmonary stenosis who underwent repair from January 2002 to September 2015 and had at least 3 serial postsurgical echocardiograms spanning from infancy to early childhood (<8 years). Student's t test was performed to compare patients who underwent valve sparing (VS) versus transannular patch (TAP) repair. ANOVA was used to track measures of ventricular systolic function over time.

RESULTS

We analyzed 151 echocardiograms performed on 42 patients. Pulmonary regurgitation (PR, moderate or severe) and the RV to left ventricular (LV) basal dimension ratio were higher in TAP patients (P < .04 at all-time points). Along with a significant increase in RV basal diameter Z-score in the TAP group (P < .001), there was an improvement in RV and LV GLS over time in both groups (P < .001). The LV GLS at last follow-up was lower in patients who underwent reoperation than those who did not (P = .050). LV GLS at the last follow-up echocardiogram was lower in patients with significant PR than those without (P < .001).

CONCLUSIONS

Ventricular function appeared improve over time from the initial postoperative period in TOF patients. TAP repair was associated with a progressively higher RV/LV ratio in young children. GLS and RV/LV basal diameter ratio may be useful when following young children after TOF repair. Further research is necessary to understand the trajectory of ventricular functional and volumetric changes in young children in order to provide the most effective lifetime management of patients with TOF.

Outcomes After Aortopulmonary Window for Hypoplastic Pulmonary Arteries and Dual-Supply Collaterals

BACKGROUND

Our institutional approach to tetralogy of Fallot with major aortopulmonary collateral arteries (MAPCAs) emphasizes early unifocalization and complete repair (CR). In the small subset of patients with dual-supply MAPCAs and confluent but hypoplastic central pulmonary arteries (PAs), our surgical approach is early creation of an aortopulmonary window (APW) to promote PA growth. Factors associated with successful progression to CR and mid-term outcomes have not been assessed.

METHODS

Clinical data were reviewed. PA diameters were measured offline from angiograms prior to APW and on follow-up catheterization >1 month after APW but prior to any additional surgical interventions.

RESULTS

From November 2001 to March 2018, 352 patients with tetralogy of Fallot/MAPCAs underwent initial surgery at our center, 40 of whom had a simple APW with or without ligation of MAPCAs as the first procedure (median age, 1.4 months). All PA diameters increased significantly on follow-up angiography. Ultimately, 35 patients underwent CR after APW. Nine of these patients (26%) underwent intermediate palliative operation between 5 and 39 months (median, 8 months) after APW. There were no early deaths. The cumulative incidence of CR was 65% 1 year post-APW and 87% at 3 years. Repaired patients were followed for a median of 4.2 years after repair; the median PA:aortic pressure ratio was 0.39 (range, 0.22 to 0.74).

CONCLUSIONS

Most patients with tetralogy of Fallot/MAPCAs and hypoplastic but normally arborizing PAs and dual-supply MAPCAs are able to undergo CR with low right ventricular pressure after APW early in life. Long-term outcomes were good, with acceptable PA pressures in most patients.