The Failed Bidirectional Glenn Shunt: Risk Factors for Poor Outcomes and the Role of Early Reoperation.

Background: Bidirectional Glenn shunt (BDG) failure carries high morbidity and mortality but the clinical factors associated with failure and the optimal management strategy are understudied. Methods: A total of 217 patients undergoing BDG at our institution between 1989 and 2020 were retrospectively reviewed and categorized as success or failure. Failure was defined as the need for reoperation (BDG takedown, reoperation for correction of cardiac defect, and/or transplantation) at any time postoperatively; operative mortality (death attributable to BDG malfunction occurring during the index hospitalization for BDG or within 30 days of discharge); or late mortality (death directly attributable to BDG malfunction occurring prior to Fontan or next-stage palliation). Univariate and binary logistic regression analyses were performed. Results: BDG failure occurred in 14 (6.5%) patients. Univariate predictors were: hypoplastic left heart syndrome (P = .037), right ventricular (RV) dominance (P = .010), greater pre-BDG pulmonary vascular resistance (PVR) (P = .012), concomitant atrioventricular valve repair (P = .020), prolonged pleural drainage (P = .001), intensive care unit (P<.001) and hospital (P = .002) stays, and extracorporeal membrane oxygenation (ECMO) requirement (P<.001). Multivariate predictors were: RV dominance (P = .002), greater PVR (P = .041), ICU (P<.001) and hospital (P = .020) stays, and need for ECMO (P<.001). As many as 10 of 14 (71%) patients with BDG failure died. Reoperation was performed for 10 patients with BDG failure. Five reoperation patients survived until discharge, with four patients alive at last follow-up (mean 7.9 years). Survivors underwent reoperation earlier than nonsurvivors (36 vs. 94 days). Conclusions: BDG failure carries high mortality, but preoperative predictors and postoperative indicators of failure exist. Early BDG takedown and insertion of aorta-pulmonary shunt may allow survival.

Unicuspid Aortic Valve Repair Using Geometric Ring Annuloplasty.

BACKGROUND: Unicuspid aortic valves (Sievers type 2 bicuspid) are characterized by major fusion and clefting of the right-left coronary commissure, and minor fusion of the right-noncoronary commissure. Repair has been difficult because of two fusions, variable relative sinus sizes, and peripheral leaflet deficiencies or tears after balloon valvuloplasty. METHODS: Twenty unicuspid aortic valves patients underwent valve repair in nine institutions. Right-left major fusion and right-noncoronary minor fusion occurred in 17 of 20 (85%). Commissurotomy was performed on the minor fusion, and a bicuspid annuloplasty ring with circular base geometry and two 180-degree subcommissural posts was sutured beneath the annulus, equalizing the annular circumferences of the fused and nonfused cusps. The nonfused leaflet was plicated, and the cleft in the major fusion was closed linearly until leaflet effective heights and lengths became greater than 8 mm and equal, respectively. RESULTS: Average age (mean ± SD) was 22.3 ± 12.3 years (range, 13 to 58), 12 of 20 (60%) were symptomatic, 10 of 20 (50%) required aortic aneurysm resection. Pre-repair hemodynamic data included mean systolic valve gradient 25.8 ± 12.9 mm Hg, aortic insufficiency grade 2.9 ± 1.2, and annular diameter 24.7 ± 3.3 mm. No mortality or major complications occurred. Post-repair annular (ring) size was 20.5 ± 1.3 mm, mean gradient fell to 16.2 ± 5.9 mm Hg, and aortic insufficiency grade decreased to 0.1 ± 0.3 (P < .001). At an average follow-up of 11 months (range, 1 to 22), all 20 patients were asymptomatic and had returned to full activity. CONCLUSIONS: Aortic ring annuloplasty reduced annular diameter effectively, recruiting more leaflet to midline coaptation. Minor fusion commissurotomy and annular remodeling to 180-degree commissures converted UAV repair to a simple and reproducible procedure.

Extracardiac Fontan Fenestration Device Closure with Amplatzer Vascular Plug II and Septal Occluder: Procedure Results and Medium-Term Follow-Up.

The objective of this study was to determine medium-term morbidity and mortality of patients who have undergone device closure of an extracardiac Fontan fenestration with an Amplatzer Vascular Plug II (AVPII) or Septal Occluder (ASO). A secondary objective was to compare medium-term morbidity and mortality between these patients and other fenestrated Fontan patients. A retrospective chart review was performed on patients who underwent an extracardiac fenestrated Fontan procedure between 1992 and 2015 at Cardinal Glennon Children's Medical Center. Procedural and follow-up data were obtained and compared between those who underwent fenestration closure and those who did not. Additional outcome measures included whether the fenestration had spontaneously closed, morbidity and mortality, oxygen saturations, and hemodynamics pre- and post-closure. Fifty-nine of 118 patients (50%) with a fenestrated Fontan underwent 60 device closures of the fenestration. Thirty-two (53%) of these were with the AVPII and 28 (47%) with the ASO. There was one device embolization. At a median follow-up of 3.9 years, five patients suffered morbidity, including 2 with arrhythmias, 1 with plastic bronchitis, 1 with protein losing enteropathy, and 1 with stroke. There were no cardiopulmonary deaths in this group. Twenty-three of 118 patients (19%) had spontaneous closure. There was no difference in morbidity and mortality between patients who underwent percutaneous fenestration closure and those who either had spontaneous closure or a persistently patent fenestration. Device closure of Fontan fenestrations is a safe and effective procedure with minimal morbidity and mortality comparable to other patients with fenestrations.

A novel mutation of the MYH7 gene in a patient with hypertrophic cardiomyopathy.

Goel N, Huddleston CB, Fiore AC. A novel mutation of the MYH7 gene in a patient with hypertrophic cardiomyopathy. Turk J Pediatr 2018; 60: 315-318. Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by asymmetric cardiac hypertrophy due to inherited mutations in genes that encode sarcomeric proteins. MYH7, which encodes ß-myosin heavy chain, is among the most commonly mutated genes in patients affected by HCM. We aimed to identify the specific mutation responsible for HCM in a six-month old Caucasian patient. NextGen DNA sequencing revealed a novel p.Ala1328Thr (A1328T) mutation of MYH7 in the affected patient as well as his asymptomatic father and asymptomatic brother. The clinical details of this mutation are described for the first time in this report. The genetic variant affects a residue that is highly conserved across species. Theoretical analysis suggests that A1328T is very likely deleterious to ß-myosin heavy chain protein structure and function. Furthermore, this novel mutation was not observed with any significant frequency in approximately 6,500 healthy individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, underlining the potential pathogenicity of this variant.

Type A Aortic Dissection After the Ross Procedure.

We describe a case of type A aortic dissection in a 25-year-old woman who had undergone a Ross procedure for aortic valve endocarditis 13 years previously. She was pregnant and noted to have significant enlargement of the aortic root during the latter portion of the third trimester of her pregnancy. An echocardiogram after delivery demonstrated new aortic valve insufficiency in addition to an aortic root diameter of 6.5 cm. A computed tomography angiogram demonstrated a type A aortic dissection involving only the very proximal portion of the ascending aorta. At operation, the dissection was found to be limited to the pulmonary autograft. This was repaired using a valve-sparing technique. Her postoperative course was uneventful, and the aortic valve has shown only trace insufficiency at 3 years of follow-up.

Heart transplantation in children with intellectual disability: An analysis of the UNOS database.

Heart transplantation in children with intellectual disability (ID) is an issue of debate due to the shortage of available donor organs. We sought to perform the first large-scale retrospective cohort study describing the prevalence and outcomes of heart transplantation in this population. The United Network of Organ Sharing database was queried from 2008 to 2015 for pediatric patients (age <19 years) receiving first, isolated heart transplant. Recipients were divided into three subgroups: definite ID, probable ID, and no ID. The chi-square test was used to compare patients' baseline characteristics. Kaplan-Meier and Cox proportional hazard regression analyses were used to estimate the association between ID and death-censored graft failure and patient survival. Over the study period, 565 pediatric patients with definite (131) or probable (434) ID received first heart transplant, accounting for 22.4% of all first pediatric heart transplants (n=2524). Recipients with definite ID did not significantly differ from those without ID in terms of gender, ethnicity, ischemia time, severity of pretransplant condition (waitlist status, mechanical ventilation, inotrope dependence, ECMO, VAD, PVRI, infection prior to transplant), or incidents of acute rejection within the first year. ID was associated with prolonged waitlist time (P<.001). Graft and patient survival at 3 years was equivalent between children with and without ID (P=.811 and .578, respectively). We conclude that intellectual disability is prevalent in children receiving heart transplants, with 22.4% of recipients over the study period having definite or probable ID. ID does not appear to negatively affect transplantation outcomes. Future studies are needed to assess long-term outcomes of transplantation in this population.

Apical Aortic Conduit Infection 27 Years After Repaired Left Ventricular Outflow Tract Obstruction.

Left ventricle to aortic conduits were used for the treatment of complex left ventricular outflow tract obstruction in the pediatric population in the mid-1970s. Although this technique has been largely replaced by the Ross-Konno procedure, many patients still have functioning apicoaortic conduits in place today. Few clinical reports or case series exist in pediatric cohorts documenting the natural history or potential long-term complications of this prosthesis. In this report, we describe our experience managing a patient with Shone's syndrome and an apical aortic porcine-valved conduit remnant that became infected 17 years postconduit valve excision for valvular insufficiency.

Hybrid versus Norwood procedure for hypoplastic left heart syndrome: contemporary series from a single center.

OBJECTIVE: Two different strategies have emerged in the initial palliation for hypoplastic left heart syndrome, the conventional Norwood operation and the so-called hybrid procedure. We have used each of these at our center. The purpose of the present study was to compare the outcomes of both procedures. METHODS: From 2007 to 2012, 40 patients presented to the Cardinal Glennon Children's Medical Center with hypoplastic left heart syndrome or 1 of its variants. Of the 40 patients, 24 underwent a hybrid procedure and 16 a Norwood procedure for initial palliation. The medical records, echocardiograms, and cardiac catheterization data were retrospectively reviewed. Standard statistical analysis was performed. RESULTS: The patients who underwent the hybrid procedure weighed less than those who underwent the Norwood procedure. Overall unadjusted survival was better in the Norwood group, although this did not reach statistical significance. Overall hospital resource usage was similar in both cohorts, taking into account both first and second palliation stages. CONCLUSIONS: In our review, we found no statistically significant difference in survival or resource usage between those patients undergoing the Norwood procedure and those undergoing a hybrid procedure as initial palliation for hypoplastic left heart syndrome.

Comparison of fenestrated and nonfenestrated patients undergoing extracardiac Fontan.

BACKGROUND: The purpose of this study is to compare morbidity and mortality between fenestrated (F, 61 patients) and nonfenestrated (NF, 54 patients) extracardiac Fontan patients during two eras from July 1995 to December 2010: era 1(1995 to 2004) and era 2 (2005 to 2010). METHODS: Variables evaluated included morphology, hemodynamics, chest tube volume and duration, intensive care and hospital stay, oxygen saturation, neurologic events, rhythm, and readmissions for chylous effusions. Follow-up in 114 hospital survivors was longer in the nonfenestrated cohort (F, 5.0 ± 3.3 years; NF, 7.1 ± 4.6 years; p < 0.005). RESULTS: Cohorts were similar in body size, morphology, and hemodynamics. Fenestration in hypoplastic left heart syndrome was appreciatively higher in era 2. Bypass time (F, 69 ± 27 minutes; NF, 57 ± 21 minutes) and conduit size (F, 18.8 mm; NF, 19.1 mm) were similar. There was 1 early nonfenestrated Fontan death (1 of 54; 2%) and 4 late deaths (F, 2 of 61, 5%; NF, 2 of 53, 4%; p = 0.86). Room air saturation was higher in NF patients (F, 89%; NF, 94%; p < 0.05). Total chest tube volume was similar, but fenestration was associated with greater chest tube drainage among hypoplastic left heart patients (HLHS, 5,582 ± 3,286 mL; non-HLHS, 3,405 ± 2,533 mL; p = 0.06; odds ratio; 2.0). Readmission to treat chylous effusions, loss of sinus rhythm, actuarial freedom from death, all neurologic events, pacemaker insertion, and Fontan takedown were similar in both cohorts. CONCLUSIONS: Fenestration was associated with lower discharge oxygen saturations, but late outcomes in fenestrated and nonfenestrated patients are equivalent.

Evolution of mitral valve replacement in children: a 40-year experience.

BACKGROUND: This report reviews our 40-year experience with pediatric mitral valve replacement (MVR) with respect to mortality, valve-related morbidity, and reoperation risk factors. METHODS: From 1970 to 2010, 97 patients have undergone a total of 136 MVRs. Median age was 8 years (2 weeks to 18 years), 41 patients (42%) were less than 5 years, and 16 were infants (17%). Etiology was congenital in 65 patients (67%), rheumatic in 27 (28%), and endocarditis in 5 (5%). Regurgitation was the predominant lesion in 67 patients (69%), stenosis in 23 (24%), and mixed in 7 (7%) patients. Mechanical valves (ball, n=11; or bileaflet disc, n=66) and xenografts (porcine, n=14; bovine, n=2) were used in 93 initial MVR patients. Since 2002, 5 children have undergone Ross MVR with a pulmonary autograft in 3 and an aortic homograft in 2. RESULTS: Hospital mortality was 6% (6 of 97). There were 23 late deaths and 5 patients have required cardiac transplantation. Thirty-five year actuarial survival was 71%. Age less than 2 years, MVR prior to 1980, atrioventricular septal defect, univentricular heart, and additional left side obstructions were significant predictors of death. Mean follow-up was 12.8±10.1 years (range, 2 months to 38 years). Seventeen patients with mechanical valves experienced systemic emboli in 9 (10%), valve thrombosis in 5 (6%), and bleeding requiring transfusion in 3 (3%) patients. Thirty-two patients required reoperations (35%) from 3 months to 14 years (mean, 6.5±4.4 years) after initial MVR. Actuarial freedom from reoperation at 35 years was 63%. Variables associated with mitral re-replacement were younger age, small weight, valve diameter less than 23 mm, MVR prior to 1980, and type of implanted valves (xenograft, single-leaflet disk, ball-caged, or human valves). CONCLUSIONS: Pediatric MVR can be performed with low initial mortality but should be reserved for medical and reconstruction failure because reoperation, valve-related complications, and late mortality are high. Bileaflet prostheses larger than 23 mm have the lowest reoperation risk. Ross MVR may offer select patients a durable tissue valve without lifelong anticoagulation and its associated complications.

A bovine jugular vein conduit: a ten-year bi-institutional experience.

BACKGROUND: We retrospectively reviewed the 12-year (1999 to 2010) clinical and echocardiographic performance of 232 bovine jugular vein conduits for extracardiac right ventricular outflow tract reconstruction in non-Ross patients. METHODS: The bovine jugular vein conduit cohorts, group 1 (12 to 14 mm), group 2 (16 to 18 mm), and group 3 (20 to 22 mm), had mean follow-up of 48 ± 30 months. Graft dysfunction is defined as right ventricular outflow tract obstruction with peak echo Doppler gradient greater than 40 mm Hg or grade 3/4 valve regurgitation. Graft failure is the need for conduit replacement or transcatheter or surgical reintervention. RESULTS: Early mortality (4 of 232; 2%) and late mortality (8 of 228; 3.5%) were not conduit related. Twenty-four conduits (10%) were explanted. Mean implant Z score was significantly lower for group 1 (1.7±0.08 versus group 2, 2.7±0.6, or group 3, 2.5±1.5; p=0.001). Ten-year actuarial survival (group 1, 84% versus 2, 100%, and 3, 99%; p=0.001) and freedom from conduit dysfunction (group 1, 64%; group 2, 92%; and group 3, 90%) and failure (group 1, 75%; 2, 82%; and 3, 91%; p=0.002) were significantly better for groups 2 and 3. CONCLUSIONS: Bovine jugular vein is an excellent immediate substitute for right ventricular outflow tract reconstruction, with early durability superior to that of pulmonary homografts reported at similar follow-up. Conduits larger than 14 mm have improved performance. Longer follow-up will define the structural integrity and efficacy of this prosthesis.

A comparison of the modified Blalock-Taussig shunt with the right ventricle-to-pulmonary artery conduit.

BACKGROUND: This study compared the modified Blalock-Taussig (MBT) shunt with the right ventricle-to-pulmonary artery (RVPA) conduit with respect to outcome and PA growth. METHODS: PA growth was assessed in 19 MBT patients and in 15 RVPA patients before stage 2 palliation for hypoplastic left heart syndrome. The RVPA was done with a ringed Gore-Tex tube (W. L. Gore and Assoc, Flagstaff, AZ) at each anastomosis. RESULTS: The two cohorts had similar pre-Glenn demographic and hemodynamic data. No patient required transcatheter or surgical intervention on the shunt or PAs after stage 1 palliation. The branch PA growth was better in RVPA (McGoon ratio: MBT, 1.5±0.2 vs RVPA, 2.0±0.6; p<0.003) and was significantly more balanced (right-to-left PA area ratio: MBT, 1.5±0.5 vs RVPA, 0.9±0.6; p=0.002). The Nakata index trended higher in RVPA (MBT, 242A±90 mm2/m2 vs RVPA, 267±95 mm2/m2, p=0.2). After stage 2 palliation, oxygen saturation trended higher in the RVPA (81%±5%) vs MBT cohort (77%±8%, p<0.08). CONCLUSIONS: The Norwood operation using a RVPA nonvalved conduit is associated with improved branch PA growth.

Rastelli operation for transposition of the great arteries with ventricular septal defect and pulmonary stenosis.

BACKGROUND: The optimal surgical treatment of patients with transposition of the great arteries, ventricular septal defect, and pulmonary stenosis is controversial. Although the Rastelli operation has been standard surgical management of this lesion, aortic root translocation with right ventricular outflow tract (RVOT) reconstruction (Nikaidoh) and the pulmonary artery translocation (Lecompte) or REV (réparation a l'étage ventriculaire) are surgical alternatives more recently introduced to treat this complex lesion. This report reviews our 20-year experience with the Rastelli procedure and attempts to compare our outcomes with those recently published using the Nikaidoh and REV procedures. METHODS: Between 1988 and 2008, 40 patients (median age, 4 years; range, 9 months to 17 years) underwent Rastelli operation at our institutions. The RVOT was obstructed in 32 and atretic in 8. Follow-up was available for all but one patient (mean follow-up, 8.6±5.6 years). The RVOT was reconstructed with homograft (n=25), bovine jugular vein (n=8), nonvalved Dacron tube (n=5), or a porcine valved conduit (n=2). Two patients required a pacemaker. RESULTS: There were no early, but three late deaths and one heart transplantation 12 years postoperative the Rastelli operation. Kaplan-Meier survival was 93% at 5, 10, and 20 years. Univariate risk factors for death or transplantation included surgery before 1998 (p=0.03) and concomitant noncardiac anomalies (p=0.001). Sixteen patients (40%) had reoperation for right ventricular-pulmonary artery conduit stenosis (mean, 7.8±3.8 years) without mortality. Freedom from conduit replacement was 86%, 74%, 63%, and 59% at 5, 10, 15, and 20 years, respectively. Multivariate analysis revealed that the risk factors of conduit replacement were younger age at operation (p=0.001) and surgery before 1998 (p<0.001). Two patients (5%) required reoperation for left ventricular outflow tract obstruction. At follow-up, there were no sudden unexplained deaths, and New York Heart Association functional class is I or II. CONCLUSIONS: The Rastelli procedure is a low-risk operation with regard to early and late mortality and reoperation for left ventricular outflow tract obstruction. Conduit change operations will be required in most patients regardless of the technique of repair, but currently can be performed with low morbidity and mortality. These midterm outcomes after the Rastelli operation should serve as a basis for comparison with surgical alternatives more recently introduced for transposition of the great arteries and ventricular septal defect with RVOT obstruction.