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.

Airway Characteristics of Patients With 22q11 Deletion Undergoing Pulmonary Artery Reconstruction Surgery: Retrospective Cohort Study.

OBJECTIVES: We have previously shown that patients with a chromosome 22q11 microdeletion are at risk for prolonged respiratory failure after pulmonary artery reconstruction surgery compared with those with normal genotype. We sought to describe preexisting airway abnormalities in this patient population and examine relationships between airway abnormalities and outcomes. DESIGN: Single-center retrospective chart review from Society of Thoracic Surgery and Pediatric Cardiac Critical Care Consortium databases and the electronic medical record. SETTING: Lucile Packard Children's Hospital at Stanford from September 2017 to February 2019. PATIENTS: All patients undergoing pulmonary artery reconstruction surgery were considered for inclusion. INTERVENTIONS: We identified 127 patients meeting study inclusion criteria. Thirty-nine patients met specific criteria and underwent screening preoperative bronchoscopy including microdirect laryngoscopy and lower airway examination. Postoperative bronchoscopy was performed at the discretion of the intensive care team. MEASUREMENTS AND MAIN RESULTS: Airway abnormalities were detected in 25/26 of children (96%) with a chromosome 22q11 deletion who underwent preoperative bronchoscopy. Upper and lower airway pathologies were found in 19/25 (73%) and 21/25 (81%) patients, respectively, and it was common for patients to have more than one abnormality. Presence of 22q11 deletion was associated with longer duration of mechanical ventilation (9.1 vs 4.3 d; p = 0.001), use of noninvasive positive pressure support (13 vs 6 d; p = 0.001), and longer hospital stays (30 vs 14 d; p = 0.002). These outcomes were worse when compared with patients with known airway abnormalities who did not have 22q11 deletion. CONCLUSIONS: Preexisting upper and lower airway pathologies are common in patients with a chromosome 22q11 deletion who undergo pulmonary artery reconstruction surgery. Despite similar postoperative hemodynamics and outcomes as their counterparts without 22q11 deletion, 22q11 deletion is associated with more postoperative respiratory complications not entirely explained by preexisting airway abnormalities.

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 to 2019 and received a postoperative surveillance catheterization at our center 6-24 months after surgery. Associations between intraoperative and catheter hemodynamic data were analyzed. A total of 163 patients were included. Median systolic PA pressure was 30 (quartiles 26, 35) and 35 (28, 42) mm Hg intraoperatively and at catheterization 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 10 mm Hg 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 a greater discrepancy between intraoperative and catheterization values. PA systolic pressure and the PA:aortic systolic pressure ratio measured immediately after repair remains 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.

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.

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.

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.

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.

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.

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.

Pulmonary hemorrhage in children with Alagille syndrome undergoing cardiac catheterization.

OBJECTIVES: To evaluate the incidence, severity, and outcomes of pulmonary hemorrhage in children with Alagille syndrome (AGS) undergoing cardiac catheterization, and to find variables associated with hemorrhage in this population. BACKGROUND: Children with AGS have a high incidence of bleeding complications during invasive procedures. It has been our impression that catheterization-associated pulmonary hemorrhage is more common in children with AGS, but there are no published data on this topic. METHODS: This was a retrospective single institution study of children with AGS undergoing catheterization from 2010 to 2018. Pulmonary hemorrhage was defined as angiographic or fluoroscopic evidence of extravasated blood in the lung parenchyma, or blood suctioned from the endotracheal tube with documentation of pulmonary hemorrhage by the anesthesiologist or intensivist. Univariate comparisons were made between catheterizations that did and did not have pulmonary hemorrhage. RESULTS: Thirty children with AGS underwent 87 catheterizations, 32 (37%) with interventions on the branch pulmonary arteries (PA). There were 26 (30%) procedures with hemorrhage, the majority (65%) of which were self-limited or required less than 24 hr of mechanical ventilation. Moderate and severe hemorrhage occurred only in children with tetralogy of Fallot (TOF; 5 of 14, 36%). A higher right ventricle to aorta systolic pressure ratio (1.0 [0.85-1.1] vs. 0.88 [0.59-1.0], p = .029) and interventions on the branch PAs (14 of 26, 54% vs. 18 of 61, 30%, p = .032) were associated with hemorrhage. CONCLUSIONS: Pulmonary hemorrhage was common in children with AGS undergoing both intervention and diagnostic cardiac catheterization, and was associated with TOF, higher RV to aorta pressure ratio, and interventions on the branch PAs.

Platelet Administration During Cardiopulmonary Bypass in Neonates: A Universal Therapy Applied in a Novel Way.

Advances in pharmaceuticals (eg, factor concentrates), laboratory testing (eg, rotational thromboelastometry), and processes (eg, transfusion protocols) have contributed to improved outcomes regarding transfusion in neonates undergoing surgical repair for congenital heart disease. A novel strategy, platelets administered during the rewarming phase of cardiopulmonary bypass, as a solution to improved hemostasis, was prospectively evaluated in 42 neonates. Improved intraoperative and postoperative hemostasis was observed in neonates given platelets during the rewarming phase of cardiopulmonary bypass.

The Congenital Cardiac Anesthesia Society-Society of Thoracic Surgeons Cardiac Anesthesia Database Collaboration.

Multi-institutional databases and registries have proliferated over the last decade in all specialties of medicine. They may be especially helpful in low-frequency/high-acuity fields such as pediatric and congenital heart diseases. The Society of Thoracic Surgeon's Congenital Heart Surgery Database (STSCHSD) is the largest single data set for the congenital heart disease population and includes contemporaneous data from over 120 programs in the United States (and several outside of the United States), capturing greater than 98% of the congenital cardiac surgical procedures in the United States. In 2010, the Congenital Cardiac Anesthesia Society partnered with the STSCHSD to incorporate anesthesia-related elements into the data set. Voluntary site participation in the anesthesia data has grown steadily. Currently, over 60 sites performing more than 60% of cardiac bypass procedures in the STSCHSD are submitting anesthesia data annually into the STSCHSD. Anesthesia data include perioperative medication usage, modalities for hemodynamic and neurologic monitoring, blood product, antifibrinolytic and procoagulant use, and anesthesia-related adverse events. This special article provides a descriptive summary of relevant findings to date, reflecting the wide variety in anesthesia practice patterns present among institutions and illustrates the functionality of a multisite registry in pediatric cardiac anesthesia which can be utilized both locally and nationally.

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.

Assessment of airway abnormalities in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals.

BACKGROUND: Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/MAPCAs) are at risk for post-operative respiratory complications after undergoing unifocalisation surgery. Thus, we assessed and further defined the incidence of airway abnormalities in our series of over 500 children with TOF/MAPCAs as determined by direct laryngoscopy, chest computed tomography (CT), and/or bronchoscopy. METHODS: The medical records of all patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery from March, 2002 to June, 2018 were reviewed. Anaesthesia records, peri-operative bronchoscopy, and/or chest CT reports were reviewed to assess for diagnoses of abnormal or difficult airway. Associations between chromosomal anomalies and airway abnormalities - difficult anaesthetic airway, bronchoscopy, and/or CT findings - were defined. RESULTS: Of the 564 patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery at our institution, 211 (37%) had a documented chromosome 22q11 microdeletion and 28 (5%) had a difficult airway/intubation reported at the time of surgery. Chest CT and/or peri-operative bronchoscopy were performed in 234 (41%) of these patients. Abnormalities related to malacia or compression were common. In total 35 patients had both CT and bronchoscopy within 3 months of each other, with concordant findings in 32 (91%) and partially concordant findings in the other 3. CONCLUSION: This is the largest series of detailed airway findings (direct laryngoscopy, CT, and bronchoscopy) in TOF/MAPCAS patients. Although these findings are specific to an at-risk population for airway abnormalities, they support the utility of CT and /or bronchoscopy in detecting airway abnormalities in patients with TOF/MAPCAs.

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.

Outcomes After Initial Unifocalization to a Shunt in Complex Tetralogy of Fallot With MAPCAs.

BACKGROUND: Our approach to tetralogy of Fallot (TOF) with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) emphasizes early single-stage unifocalization and intracardiac repair. However, a subset of patients with small native pulmonary arteries (PAs) and MAPCAs undergo unifocalization to a shunt rather than simultaneous intracardiac repair. METHODS: Patients with TOF/MAPCAs who underwent complete unifocalization to a systemic-to-PA shunt by a single surgeon were reviewed. The decision to perform simultaneous intracardiac repair was based on an intraoperative flow study or empirical assessment of PA and MAPCA size. RESULTS: From November 2001 to December 2017, 57 patients with TOF/MAPCAs underwent unifocalization to a shunt at a median age of 6.9 months. Genetic abnormalities were documented in 60% of patients, including a chromosome 22q11 deletion in 25 and Alagille syndrome in 8. Twenty patients (35%) had undergone prior surgery elsewhere (n = 16) and/or at our center (n = 7). During a median follow-up of 5.4 years, 9 patients had additional surgery to revise the PA reconstruction before complete repair, and 38 patients underwent complete repair. Five years after unifocalization, survival was 74% ± 6%. At follow-up, the median PA to aortic systolic pressure ratio was 0.36 and was greater than 0.50 in 2 patients. CONCLUSIONS: In patients with the smallest MAPCAs and PAs, single-stage unifocalization to a shunt followed by intracardiac repair yields an excellent outcome in most cases.

Deletion of 22q11 chromosome is associated with postoperative morbidity after unifocalisation surgery.

BACKGROUND: A 22q11 chromosome deletion is common in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals. We sought to determine whether 22q11 chromosome deletion is associated with increased postoperative morbidity after unifocalisation surgery. METHODS: We included all patients with this diagnosis undergoing primary or revision unifocalisation ± ventricular septal defect closure at our institution from 2008 to 2016, and we excluded patients with unknown 22q11 status. Demographic and surgical data were collected. We compared outcomes between those with 22q11 chromosome deletion and those without using non-parametric analysis. RESULTS: We included 180 patients, 41% of whom were documented to have a chromosome 22q11 deletion. Complete unifocalisation was performed in all patients, and intracardiac repair was performed with similar frequency regardless of 22q11 chromosome status. Duration of mechanical ventilation was longer in 22q11 deletion patients. This difference remained significant after adjustment for delayed sternal closure and/or intracardiac repair. Duration of ICU stay was longer in patients with 22q11 deletion, although no longer significant when adjusted for delayed sternal closure and intracardiac repair. Finally, length of hospital stay was longer in 22q11-deleted patients, but this difference was not significant on unadjusted or adjusted analysis. CONCLUSION: Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals and 22q11 deletion are at risk for greater prolonged mechanical ventilation after unifocalisation surgery. Careful attention should be given to the co-morbidities of this population in the perioperative period to mitigate risks that may complicate the postoperative course.

A Prospective Assessment of Optimal Mechanical Ventilation Parameters for Pediatric Catheter Ablation.

Catheter stability, an important factor in ablation success, is affected by ventilation. Optimal ventilation strategies for pediatric catheter ablation are not known. We hypothesized that small tidal volume and positive end-expiratory pressure are associated with reduced ablation catheter movement at annular positions. Subjects aged 5-25 years undergoing ablation for supraventricular tachycardia (SVT) or WPW at two centers from March 2015 to September 2016 were prospectively enrolled and randomized to receive mechanical ventilation with either positive end-expiratory pressure of 5 cm H2O (PEEP) or 0 cm H2O (ZEEP). Movement of the ablation catheter tip at standard annular positions was measured using 3D electroanatomic mapping systems under two conditions: small tidal volume (STV) (3-5 mL/kg) or large TV (LTV) (6-8 mL/kg). 58 subjects (mean age 13.8 years) were enrolled for a total of 266 separate observations of catheter movement. STV ventilation was associated with significantly reduced catheter movement, compared to LTV at all positions (right posteroseptal: 2.5 ± 1.4 vs. 5.2 ± 3.1 mm, p < 0.0001; right lateral: 2.7 ± 1.6 vs. 6.3 ± 3.5 mm, p < 0.0001; left lateral: 1.8 ± 1.0 vs. 4.3 ± 1.9 mm, p < 0.0001). The presence or absence of PEEP had no effect on catheter movement. In multivariable analysis, STV was associated with a 3.1-mm reduction in movement (95% CI 2.6-3.5, p < 0.0001), adjusting for end-expiratory pressure, annular location, and patient size. We conclude that STV ventilation is associated with reduced ablation catheter movement compared to a LTV strategy, independent of PEEP and annular position.