Hypoplastic left heart syndrome [HLHS]: treatment options in present era

Comparison of Morbidity and Mortality Outcomes between Hybrid Palliation and Norwood Palliation Procedures for Hypoplastic Left Heart Syndrome: Meta-Analysis and Systematic Review

Background/Objectives: Hybrid palliation (HP) procedures for hypoplastic left heart syndrome (HLHS) are increasing. Our objective was to compare mortality and morbidity following HP and NP (Norwood palliation) procedures. Methods: Systematic review and meta-analysis of HLHS patients of peer-reviewed literature between 2000 and 2023. Mortality and/or heart transplantation in HP versus NP in the neonatal period, interstage period, and at 1, 3 and 5 years of age, and morbidity including completion of Stage II and Stage III palliation, unexpected interventions, pulmonary artery pressures, right ventricle function, neurodevelopmental outcomes and length of hospital stay were evaluated. Results: Twenty-one (meta-analysis: 16; qualitative synthesis: 5) studies evaluating 1182 HLHS patients included. HP patients had higher interstage mortality (RR = 1.61; 95% CI: 1.10-2.33; p = 0.01) and 1-year mortality (RR = 1.22; 95% CI: 1.03-1.43; p = 0.02) compared to NP patients without differences in 3- and 5-years mortality. HP procedure in high-risk HLHS patients had lower mortality (RR = 0.48; 95% CI: 0.27-0.87; p = 0.01) only in the neonatal period. HP patients underwent fewer Stage II (RR = 0.90; 95% CI: 0.81-1.00; p = 0.05) and Stage III palliation (RR = 0.78; 95% CI: 0.69-0.90; p < 0.01), had more unplanned interventions (RR = 3.38; 95% CI: 2.04-5.59; p < 0.01), and longer hospital stay after Stage I palliation (weighted mean difference = 12.88; 95% CI: 1.15-24.62; p = 0.03) compared to NP patients. Conclusions: Our study reveals that HP, compared to NP for HLHS, is associated with increased morbidity risk without an improved survival rate.

Histotripsy: A Method for Mechanical Tissue Ablation with Ultrasound

Histotripsy is a relatively new therapeutic ultrasound technology to mechanically liquefy tissue into subcellular debris using high-amplitude focused ultrasound pulses. In contrast to conventional high-intensity focused ultrasound thermal therapy, histotripsy has specific clinical advantages: the capacity for real-time monitoring using ultrasound imaging, diminished heat sink effects resulting in lesions with sharp margins, effective removal of the treated tissue, a tissue-selective feature to preserve crucial structures, and immunostimulation. The technology is being evaluated in small and large animal models for treating cancer, thrombosis, hematomas, abscesses, and biofilms; enhancing tumor-specific immune response; and neurological applications. Histotripsy has been recently approved by the US Food and Drug Administration to treat liver tumors, with clinical trials undertaken for benign prostatic hyperplasia and renal tumors. This review outlines the physical principles of various types of histotripsy; presents major parameters of the technology and corresponding hardware and software, imaging methods, and bioeffects; and discusses the most promising preclinical and clinical applications.

The outcomes of fetal aortic valvuloplasty in critical aortic stenosis: A systematic review and meta-analysis

BACKGROUND

Critical aortic stenosis that appears in mid-gestation tends to develop to growth retardation of left ventricle, known as hypoplastic left heart syndrome (HLHS). Despite better clinical management of HLHS, the morbidity and mortality rates of univentricular circulation patients remain high. In this paper, we sought to perform a systematic review and meta-analysis to know the outcomes of fetal aortic valvuloplasty in critical aortic stenosis patients.

METHODS

This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. A systematic search on fetal aortic valvuloplasty procedure for critical aortic stenosis was performed through PubMed, Scopus, EBSCOhost, ProQuest, and Google Scholar. The primary endpoint of each group was overall mortality. We used R software (version 4.1.3) to estimate the overall proportion of each outcome using random-effects model of proportional meta-analysis.

RESULTS

A total of 389 fetal subjects from 10 cohort studies were included in this systematic review and meta-analysis. Fetal aortic valvuloplasty (FAV) was successfully performed in 84% of patients. It revealed a successful conversion to biventricular circulation rate of 33% with a mortality rate of 20%. Bradycardia and pleural effusion requiring treatment were two most common fetal complications, whereas maternal complication reported was only placental abruption in one patient.

CONCLUSIONS

FAV has a high technical success rate with the ability to achieve biventricular circulation and a low rate of procedure-related mortality if carried out by experienced operators.

Current state of the art in hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a complex congenital heart condition in which a neonate is born with an underdeveloped left ventricle and associated structures. Without palliative interventions, HLHS is fatal. Treatment typically includes medical management at the time of birth to maintain patency of the ductus arteriosus, followed by three palliative procedures: most commonly the Norwood procedure, bidirectional cavopulmonary shunt, and Fontan procedures. With recent advances in surgical management of HLHS patients, high survival rates are now obtained at tertiary treatment centers, though adverse neurodevelopmental outcomes remain a clinical challenge. While surgical management remains the standard of care for HLHS patients, innovative treatment strategies continue to be developing. Important for the development of new strategies for HLHS patients is an understanding of the genetic basis of this condition. Another investigational strategy being developed for HLHS patients is the injection of stem cells within the myocardium of the right ventricle. Recent innovations in tissue engineering and regenerative medicine promise to provide important tools to both understand the underlying basis of HLHS as well as provide new therapeutic strategies. In this review article, we provide an overview of HLHS, starting with a historical description and progressing through a discussion of the genetics, surgical management, post-surgical outcomes, stem cell therapy, hemodynamics and tissue engineering approaches.

The role of neutrophil-to-lymphocyte ratio in predicting mortality after bidirectional Glenn procedure

This study aimed to address the role of various inflammation-related blood indices for the assessment of in-hospital outcomes in subjects undergoing Glenn procedure. Subjects who underwent the Glenn procedure for hypoplastic left heart syndrome were analysed retrospectively. Subjects were divided into two groups: Group 1 consisted of 78 patients who were discharged, and Group 2 included 12 patients who died after surgery. Post-operative third-day neutrophil count and neutrophil-to-lymphocyte ratio value were significantly higher in the exitus group compared to the discharged group (p = 0.006 and p = 0.003, respectively). Third-day neutrophil-to-lymphocyte ratio was positively correlated with duration of intubation (r = 0.253, p = 0.018), length of stay in ICU (r = 0.296, p = 0.006) and length of hospital stay (r = 0.297, p = 0.005). Multiple logistic regression analysis revealed that patients with high third-day neutrophil-to-lymphocyte ratio (≥6) had 14.227-fold higher risk of death compared to those with lower values. In addition, higher pulmonary arterial pressure was associated with increased risk of death. Receiver operating characteristics analysis revealed that neutrophil-to-lymphocyte ratio had 66.67% sensitivity, 84% specificity, 81.61% accuracy, 40.00% positive predictive value and 94.03% negative predictive value with a cut-off point of ≥6 to predict mortality. Third-day neutrophil-to-lymphocyte ratio and increased post-operative pulmonary arterial pressure are significant predictors for in-hospital mortality in Glenn procedure recipients. A cut-off value of ≥6 for third-day neutrophil-to-lymphocyte ratio predicts mortality with 66.67% sensitivity and 84% specificity. Given its simplicity and availability, post-operative neutrophil-to-lymphocyte ratio should be monitored on a daily basis to identify patients with high risk for mortality after Glenn procedure.

First-Trimester Diagnosis of Hypoplastic Left Heart Syndrome: A Case Report

Hypoplastic left heart syndrome (HLHS) comprises a spectrum of left-sided heart anomalies resulting from left outflow or inflow obstruction. Obstruction most often occurs at the levels of the aortic valve and/or mitral valve due to stenosis or atresia. HLHS is a lethal cardiac anomaly if not treated within the first week of life. Knowledge of sonographic features could aid in early detection, which results in better planning and management of pregnancy. This report presents a case in which HLHS was discovered during a routine dating and viability sonogram, performed at 12 weeks’ gestation.