Objective To observe the difference between blood brain barrier and blood optic nerve barrier. Methods Twenty normal male SD rat sprime; optic nerve including prelaminar region, lamina cribrosa, retro-laminar region, intraorbital portion, intracanalicular portion, and intracranial portion respectively,and cerebral cortex were removed separately. Ultrastructure of endothelial cells was observed by electron microscopy. Immunohistochemical staining was used to detect the expression of transferrin receptor (OX-26) and metalloproteinase inducer (OX-47) and extravasation of fibrinogen around microvessels. Results The results of electron microscopy showed that endothelial cells of microvessels in each portion of optic nerves and cerebral cortex did share the same tight junctions. However, the number of plasmalemmal vesicles in prelaminar region was significantly more than that in cerebral cortex(P＜0.05);there was no significant difference between other parts of optic nerves (lamina cribrosa, retro- laminar region, intraorbital portion, intracanalicular portion, and intracranial portion)and cerebral cortex in the number of the plasmalemmal vesicles(Pgt;0.05). By immunohistochemical staining，the endothelial cells of microvessels in the prelaminar region showed no expression of the OX-26 and OX-47,but extravasation of fibrinogen around microvessels was found; b positive expression of OX-26 and OX-47 was observed in the endothelial cells of the microvessels in other parts of optic nerves (lamina cribrosa, retro-laminar region, intraorbital portion, intracanalicular portion, and intracranial portion) andcerebral cortex, and no fibrinogen was seen aro und the microvessels. Conclusions There is a significant difference between the endothelial cells of the microvessels in prelaminar region and cerebral cortex in the ultrastructure, markers expression, and permeability, so the microvessel s in prelaminar region lacks the typical blood brain barrier characteristics.The microvessels in other parts of optic nerves (lamina cribrosa, retro-laminar region, intraorbital portion, intracanalicular portion, and intracranial portion) have blood brain barrier properties due to its similar specialties as which in cerebral cortex. (Chin J Ocul Fundus Dis, 2006, 22: 390-393)
ObjectiveTo summarize the clinical experience in the treatment of high-risk patients with severe aortic valve disease by transcatheter aortic valve implantation (TAVI) via heart apex approach and to evaluate the early efficacy.MethodFive patients who underwent TAVI via heart apex approach from September 2017 to February 2019 in Henan Thoracic Hospital were retrospectively analyzed, including 3 males and 2 females, aged 65-84 (74.6±4.5) years.ResultAll operations were performed through a small left incision into the thoracic cavity (3-5 cm), and then through the J-Valve transport system, the aortic valve was successfully released via heart apex after precise positioning under digital subtraction angiography. One patient developed ventricular fibrillation during the operation, and the operation was completed with the assistance of emergency femoral arteriovenous catheterization cardiopulmonary bypass; one patient underwent percutaneous coronary intervention first because of severe coronary stenosis; one patient had paroxysmal atrial fibrillation during the perioperative period, and had hepatorenal insufficiency and thrombocytopenia after the operation, and was improved after medical treatment; one patient had perivalvular leak during the operation, and was improved after re-implantation of the valve; one patient was in stable condition during operation and recovered smoothly after operation. Surgery was successful in all 5 patients. The follow-up time was 2-19 months, and the early clinical effect was good.ConclusionThe short-term clinical efficacy of TAVI via heart apex approach in the treatment of high-risk severe aortic valve disease is definite and safe, but the long-term and medium-term effects need to be further evaluated.