Cellular and Molecular Mechanisms of Spinal Cord Vascularization

During embryonic central nervous system (CNS) development, the neural and the vascular systems communicate with each other in order to give rise to a fully functional and mature CNS. The initial avascular CNS becomes vascularized by blood vessel sprouting from different vascular plexus in a highly stereotypical and controlled manner. This process is similar across different regions of the CNS. In particular for the developing spinal cord (SC), blood vessel ingression occurs from a perineural vascular plexus during embryonic development. In this review, we provide an updated and comprehensive description of the cellular and molecular mechanisms behind this stereotypical and controlled patterning of blood vessels in the developing embryonic SC, identified using different animal models. We discuss how signals derived from neural progenitors and differentiated neurons guide the SC growing vasculature. Lastly, we provide a perspective of how the molecular mechanisms identified during development could be used to better understand pathological situations.

Prosthetic Subclavian-Aortic Bypass as a Safe Surgical Technique for the Coarctation of the Aorta in Adults

BACKGROUND: Coarctation represents 5-8% of congenital heart disease. Residual hypertension remains the main problem after late correction. Surgical treatment in the adult remains a challenge for the surgeon. Our prefered method used in this category is the Subclavian-aortic bypass.MATERIAL AND METHODS: We have reviewed our registry for the period of 12 years (1998- 2010) and we found a group of 18 adult patients being operated for coarctation of the aorta. The mean age of this group of patients was 24.7 ± 8.43 years (range 16-42 years). 13 were males and 5 females. RESULTS: Sugical technique: Most of the patients (13 pts, 72%) which were obviously treated with subclavian-aortic bypass with a Dacron prostheses. Mean preoperative and postoperative pressure gradients measured by echocardiography were 77.7 ± 20.16 mmHg and 22.3 ± 9.14 mmHg respectively. No mortality was observed in this series of patients. Chylothorax was the only complication observed in one patient in the early postoperative period.CONCLUSION: Coarctation of the aorta in adults is treated with optimal early results at our surgical centre. Subclavian-aortic bypass grafting requires less aortic dissection, can be performed with a partially occluding clamp, and does not compromise the spinal cord vascularization.