Optimizing Surgical Selection for Transposition With Left Ventricular Outflow Tract Obstruction.

BACKGROUND: Studies that have assessed the Rastelli and Nikaidoh operations for transposition of the great arteries (TGA) with obstructed left ventricular outflow tract obstruction (LVOTO) have not fully evaluated the anatomic drivers that may contribute to surgical selection. We present our procedural selection process for optimizing outcomes of complex TGA in the modern era. METHODS: This is a single-center, retrospective study that included pediatric patients who underwent either a Nikaidoh or Rastelli operation for the treatment of TGA-LVOTO, congenitally corrected TGA-LVOTO, or double-outlet right ventricle TGA type-LVOTO from June 2004 to June 2021. RESULTS: There were 34 patients stratified by Nikaidoh (n = 16) or Rastelli (n = 18) operation. The incidence of all postoperative complications and mortality was low, and the incidence of complications between the groups was similar. Patients were more likely to have undergone a Nikaidoh than a Rastelli if they had a pulmonary annulus >5 mm (87.5% vs 11.1%), anteriorly/posteriorly oriented great vessels (88% vs 8%), remote (80% vs 11%) or restrictive (75% vs 6%) ventricular septal defect, and right ventricular hypoplasia (50% vs 0%; all, P < .05). The resulting rates of reoperation were similar between the groups (44.0% vs 37.5%; P = .24) and largely composed of conduit replacements in the Rastelli patients and valvular repairs or replacements in the Nikaidoh group. Rates of catheter-based interventions were also similar. CONCLUSIONS: These findings suggest that for the optimal treatment of conotruncal anomalies with discordant ventriculoarterial connections, procedural selection should be based on pathoanatomic criteria that can ensure patients undergo the operation most suited to their anatomy.

Pulmonary Homograft vs Handmade Polytetrafluoroethylene-Valved Conduits After the Ross Procedure.

BACKGROUND: This study aimed to longitudinally compare expanded polytetrafluoroethylene (ePTFE)-valved conduits vs pulmonary homograft (PH) conduits after right ventricular outflow tract reconstruction in the Ross procedure. METHODS: Patients undergoing a Ross procedure from June 2004 to December 2021 were identified. Echocardiographic data, catheter-based interventions, or conduit replacements, as well as time to first reintervention or replacement, were comparatively assessed between handmade ePTFE-valved conduits and PH conduits. RESULTS: A total of 90 patients were identified. The median age and weight were 13.8 years (interquartile range [IQR], 8.08-17.80 years) and 48.3 kg (IQR, 26.8-68.7 kg), respectively. There were 66% (n = 60) ePTFE-valved conduits and 33% (n = 30) PHs. The median size was 22 mm (IQR, 18-24 mm) for ePTFE-valved conduits and 25 mm (IQR, 23-26 mm) for PH conduits (P < .001). Conduit type had no differential effect in the gradient evolution or the odds of presenting with severe regurgitation in the last follow-up echocardiogram. Of the 26 first reinterventions, 81% were catheter-based interventions, without statistically significant differences between the groups (69% PH vs 83% ePTFE). The overall surgical conduit replacement rate was 15% (n = 14), and it was higher in the homograft group (30% vs 8%; P = .008). However, conduit type was not associated with an increased hazard for reintervention or reoperation after adjusting for covariates. CONCLUSIONS: Right ventricular outflow tract reconstruction using handmade ePTFE-valved conduits after a Ross procedure provides encouraging midterm results, without a differential effect in hemodynamic performance or valve function compared with PH conduits. These results are reassuring about the use of handmade valved conduits in pediatric and young adult patients. Longer follow-up of tricuspid conduits will complement valve competency assessment.

Anatomic Position and Durability of Polytetrafluoroethylene Conduit ≥18 mm: Single-Center Experience.

BACKGROUND: Conduit longevity after right ventricular outflow tract (RVOT) reconstruction is determined by the interaction of different factors. We evaluated the relationship between conduit anatomic position and long-term durability among ≥18 mm polytetrafluoroethylene (PTFE) conduits. METHODS: A single-institution RVOT reconstructions using a PTFE conduit ≥18 mm were identified. Catheter-based interventions or the need for conduit replacement were comparatively assessed between orthotopic vs heterotopic conduit position. Time to the first reintervention, censored by death, was compared between the groups. RESULTS: A total of 102 conduits were implanted in 99 patients, with a median age of 13.2 years (interquartile range [IQR] 8.9-17.8 years), median weight of 47 kg (IQR, 29-67 kg), and body surface area of 1.4 m2 (IQR, 1-1.7 m2). Overall, 50.9% (n = 52) of conduits were placed in an orthotopic position after the Ross procedure in congenital aortic valve abnormalities (80% [n = 36]). Tetrology of Fallot in 39% (n = 18), followed by truncus arteriosus with 33% (n = 15), were the most common in the heterotopic position. Trileaflet configuration was similar (67% vs 69%; P = .32) between the groups. Survival free from reintervention was 91% (95% CI, 79-97) and 88% (95% CI, 71-95) in the orthotopic and the heterotopic group, respectively, at 5 years, without differences in the Kaplan Meier curves (log-rank >.05). CONCLUSIONS: RVOT reconstruction with PTFE conduits ≥ 8 mm showed >90% conduit survival free from replacement in our cohort at 5 years. The anatomic position of the PTFE conduit does not seem to impact intermediate durability.

Intracellular Signaling Pathways Mediating Tyrosine Kinase Inhibitor Cardiotoxicity.

Tyrosine kinase inhibitors (TKIs) are used to treat several cancers; however, a myriad of adverse cardiotoxic effects remain a primary concern. Although hypertension (HTN) is the most common adverse effect reported with TKI therapy, incidents of arrhythmias (eg, QT prolongation, atrial fibrillation) and heart failure are also prevalent. These complications warrant further research toward understanding the mechanisms of TKI-induced cardiotoxicity. Recent literature has given some insight into the intracellular signaling pathways that may mediate TKI-induced cardiac dysfunction. In this article, we discuss the cardiotoxic effects of TKIs on cardiomyocyte function, signaling, and possible treatments.