Feeding Neonates and Infants Prior to Surgery for Congenital Heart Defects: Systematic Review and Meta-Analysis.

BACKGROUND: Necrotising enterocolitis (NEC) is a significant cause of mortality and morbidity in neonates requiring cardiac surgery. Feeding practices vary significantly across institutions and remain controversial. We conducted a systematic review of the literature and a meta-analysis to identify associations between feeding practices and necrotising enterocolitis. METHODS: This study was carried out in accordance with the PRISMA guidelines. A literature search was performed in November 2022 using the Cochrane Central Register, Embase, and Pubmed. Two investigators then independently retrieved eligible manuscripts considered suitable for inclusion. Data extracted included gestational age, birth weight, sex, nature of congenital heart lesion, type of operation performed, time on ventilator, ICU stay, hospital stay, post-operative feeding strategy, and complications. The methodological quality was assessed using the Downs and Black score for all randomised control trials and observational studies. RESULTS: The initial search yielded 92 studies. After removing duplicates, there were 85 abstracts remaining. After excluding ineligible studies, 8 studies were included for the meta-analysis. There was no significant risk of NEC associated with pre-operative feeding [OR = 1.22 (95% CI 0.77,1.92)] or umbilical artery catheter placement [OR = 0.91 (95% CI 0.44, 1.89)] and neither outcome exhibited heterogeneity [I2 = 8% and 0%, respectively]. There was a significant association between HLHS and NEC [OR = 2.56 (95% CI 1.56, 4.19)] as well as prematurity and NEC [OR 3.34 (95% CI 1.94, 5.75)] and neither outcome exhibited heterogeneity [I2 = 0% and 0%, respectively]. CONCLUSIONS: There was no association between NEC and pre-operative feeding status in neonates awaiting cardiac surgery. Pre-operative feeding status was not associated with prolonged hospital stay or need for tube assisted feeding at discharge. HLHS and prematurity were associated with increased incidence of NEC.

Enhanced Biocorrosion Resistance and Cellular Response of a Dual-Phase High Entropy Alloy through Reduced Elemental Heterogeneity.

The leaching out of toxic elements from metallic bioimplants has serious repercussions, including allergies, peripheral neuritis, cancer, and Alzheimer's disease, leading to revision or replacement surgeries. The development of advanced structural materials with excellent biocompatibility and superior corrosion resistance in the physiological environment holds great significance. High entropy alloys (HEAs) with a huge compositional design space and outstanding mechanical and functional properties can be promising for bioimplant applications. However, microstructural heterogeneity arising from elemental segregation in these multiprinciple alloy systems is the Achilles heel in the development of next-generation HEAs. Here, we demonstrate a pathway to homogenize the microstructure of a biocompatible dual-phase HEA, comprising refractory elements, namely, MoNbTaTiZr, through severe surface deformation using stationary friction processing (SFP). The strain and temperature field during processing homogenized the elemental distribution, which was otherwise unresponsive to conventional annealing treatments. Nearly 15 min of the SFP treatment resulted in a significant elemental homogenization across dendritic and interdendritic regions, similar to a week-long annealing treatment at 1275 K. The SFP processed alloy showed a nearly six times higher biocorrosion resistance compared to its as-cast counterpart. X-ray photoelectron spectroscopy was used to investigate the nature of the oxide layer formed on the specimens. Superior corrosion behavior of the processed alloy was attributed to the formation of a stable passive layer with zirconium oxide as the primary constituent and higher hydrophobicity. Biocompatibility studies performed using the human mesenchymal stem cell line, showed higher viability for the processed HEA compared to its as-cast counterpart as well as conventional metallic biomaterials including stainless steel (SS316L) and titanium alloy (Ti6Al4V).

Universal implantation of temporary epicardial pacing wires after surgery for congenital heart disease: necessity or luxury?

OBJECTIVES: Routine implantation of temporary epicardial pacing wires after surgery for congenital heart disease (CHD) has recently been questioned. We evaluated the incidence of arrhythmias, arrhythmias causing haemodynamic compromise and the safety of a strategy of selective implantation of pacing wires in our unit. METHODS: All patients who underwent surgery for CHD using cardiopulmonary bypass between September 2015 and December 2016 were retrospectively enrolled in the study (n = 313). Patients were stratified into group A (universal implantation) and group B (selective implantation). Group B received pacing wires only when postoperative rhythm disturbances were anticipated based on the operating surgeon's judgement. The primary outcome was arrhythmia causing haemodynamic compromise. Outcomes were compared between unmatched and propensity matched groups. RESULTS: Forty-eight patients experienced an arrhythmia causing haemodynamic compromise (15.3%). Twenty-three patients (7.3%) experienced an arrhythmia causing haemodynamic compromise that required the use of pacing wires for therapeutic purposes (group A n = 13, group B n = 10, P = 0.34). There were no pacing wire related complications in either group. All patients in group A and 90% in group B had pacing wires when needed (P = 0.435). In group A, 89% of patients had pacing wires which were not used compared with 13% in group B (P < 0.001). Results were unchanged when repeated using propensity matching (81 pairs). CONCLUSIONS: The probability of developing a postoperative arrhythmia requiring therapeutic pacing can be predicted using the risk factors identified in our study. The routine implantation of pacing wires after surgery for CHD is not necessary. A measured reduction from universal implantation is safe.

Impact of High-Risk Characteristics in Hypoplastic Left Heart Syndrome.

BACKGROUND: Management of hypoplastic left heart syndrome (HLHS) presents many challenges. We describe our institutional outcomes for management of patients with HLHS over the past 12 years and highlight our strategy for those with highly restrictive/intact interatrial septum (R/I-IAS). METHODS: Eighty-eight neonates with HLHS underwent surgical treatment, divided equally into Era-I (n = 44, April 2006 to February 2013) and Era-II (n = 44, March 2013 to June 2018). Up to 2013, all patients with R/I-IAS were delivered at an adjacent adult hospital and then moved to our hospital for intensive care and management. From 2014, these patients were delivered at a co-located theatre in our hospital with immediate atrial septectomy. The hybrid approach was occasionally used with preference for the Norwood procedure for suitable candidates. RESULTS: One-year survival after Norwood procedure was 62.5% and 80% for Era-I and Era-II (P = not significant (ns)), respectively, and 41% of patients were categorized as high risk using conventional criteria. Survival at 1 year differed significantly between high-risk and standard-risk patients (P = 0.01). For high-risk patients, survival increased from 42% to 65% between eras (P = ns). In the R/I-IAS subgroup (n = 15), 11 underwent Norwood procedure after emergency atrial septectomy. Of these, seven born at the adjacent adult hospital had 40% survival to stage II versus 60% for the four born at the colocated theatre. Delivery in a colocated theatre reduced the birth-to-cardiopulmonary bypass median time from 445 (150-660) to 62 (52-71) minutes. CONCLUSION: Reported surgical outcomes are comparable to multicenter reports and international databases. Proactive management for risk factors such as R/I-IAS may contribute to improved overall outcomes.

Enhanced antibacterial properties and the cellular response of stainless steel through friction stir processing.

Biofilm related bacterial infection is one of the primary causes of implant failure. Limiting bacterial adhesion and colonization of pathogenic bacteria is a challenging task in health care. Here, a highly simplistic processing technique for imparting antibacterial properties on a biomedical grade stainless steel is demonstrated. Low-temperature high strain-rate deformation achieved using submerged friction stir processing resulted in a nearly single phase ultra-fine grain structure. The processed stainless steel demonstrated improved antibacterial properties for both Gram-positive and Gram-negative bacteria, significantly impeding biofilm formation during the in vitro study. Also, the processed stainless steel showed better compatibility with human fibroblasts manifested through apparent cell spreading and proliferation. The substantial antibacterial properties of the processed steel are explained in terms of the favorable electronic characteristics of the metal-oxide and by using classical Derjaguin-Landau-Verwey-Overbeek (DLVO) and the extended DLVO (XDLVO) approach at the cell-substrate interface.

Two Ventricles Are Not Better Than One in the Fontan Circulation: Equivalent Late Outcomes.

BACKGROUND: A subset of patients who underwent Fontan operations has two adequate-sized ventricles, but an anatomic biventricular circulation cannot be achieved because of complex morphology or for technical reasons. This study sought to determine whether these patients with two-ventricle Fontan circulation had superior outcomes compared with those with a single ventricle. METHODS: A binational Fontan Registry of patients (n = 1,377) was analyzed to identify those patients with two adequate ventricles. This cohort was compared with patients with single-ventricle Fontan circulation. The primary end point was a composite end point called "Fontan failure" encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV. RESULTS: A total of 79 Fontan patients with two adequate ventricles (2V) were compared with 1,291 single ventricle (1V) Fontan patients. Median follow-up for the entire cohort was 11.5 years (interquartile range, 5.1 to 18.8 years). There was no difference in unadjusted 15-year freedom from Fontan failure (2V: 81% [95% confidence interval (CI), 69% to 94%] vs 1V: 86% [95% CI, 83% to 88%], p = 0.4). Propensity-score matching for potential confounding factors yielded 75 two-ventricle Fontan patients matched with 604 single-ventricle Fontan patients, in which 15-year freedom from Fontan failure was also not different (2V: 79% [95% CI, 67% to 94%] vs 1V: 87% [95% CI, 84% to 91%], p = 0.3). CONCLUSIONS: The two-ventricle Fontan circulation does not have better outcomes compared with the single-ventricle Fontan circulation. Late outcomes may depend more on other characteristics of the Fontan circulation. This finding is relevant when the Fontan procedure is being considered as an alternative to anatomic repair in patients with complex two-ventricle morphologies.