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Background:Isolated coarctation of the aorta can be repaired by either lateral thoracotomy or sternotomy approach with end-to-end anastomosis. Most commonly, neonates with coarctation of the aorta also have hypoplasia of the arch, requiring median sternotomy and extended end-to-side anastomosis with arch augmentation. The aim of this study was to describe our experience as the institution adopted the median sternotomy approach for repair, by reviewing complications, mortality, and reintervention.Methods:Retrospective chart review of 66 patients aged 0–1 year who had arch repair performed by a single surgeon over an 8-year period was performed. Median age at surgery was 22 days (4–232) and median weight was 3.08 kg (1.25–8.0). Forty-one (62%) patients underwent median sternotomy.Results:There was 1 death from a noncardiac cause. Eighteen per cent of our patients were ≤2.5 kg. Vocal cord paresis occurred in 16% of patients under 2.5 kg and 9.5% of patients 2.5 kg or above at the time of surgery. Hypertension at 6-month follow-up was greater in patients under 2.5 kg (44%) than patients 2.5 kg or above (15%). Total surgical reintervention rate was 6%. For patients above 2.5 kg, the surgical reintervention rate was 5.4% and for patients below 2.5 kg, the surgical reintervention rate was 8.3%.Conclusion:We concluded that for neonates with coarctation of the aorta and hypoplastic arch, median sternotomy is a safe surgical approach with low morbidity and mortality with the possible advantage of reduced surgical re-intervention and mortality in the population below 2.5 kg.

Background Non-essential facultative endosymbionts can provide their hosts with protection from parasites, pathogens, and predators. For example, two facultative bacterial symbionts of the pea aphid (Acyrthosiphon pisum), Serratia symbiotica and Hamiltonella defensa, protect their hosts from parasitism by two species of parasitoid wasp. Previous studies have not explored whether facultative symbionts also play a defensive role against predation in this system. We tested whether feeding on aphids harboring different facultative symbionts affected the fitness of an aphid predator, the lady beetle Hippodamia convergens. Results While these aphid faculative symbionts did not deter lady beetle feeding, they did decrease survival of lady beetle larvae. Lady beetle larvae fed a diet of aphids with facultative symbionts had significantly reduced survival from egg hatching to pupation and therefore had reduced survival to adult emergence. Additionally, lady beetle adults fed aphids with facultative symbionts were significantly heavier than those fed facultative symbiont-free aphids, though development time was not significantly different. Conclusions Aphids reproduce clonally and are often found in large groups. Thus, aphid symbionts, by reducing the fitness of the aphid predator H. convergens, may indirectly defend their hosts’ clonal descendants against predation. These findings highlight the often far-reaching effects that symbionts can have in ecological systems.