Concave Pit-Containing Scaffold Surfaces Improve Stem Cell-Derived Osteoblast Performance and Lead to Significant Bone Tissue Formation

Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear.In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA) scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone) to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i) large microcavities of 80-120 microm in diameter and 40-100 microm in depth, which we termed primary; and (ii) smaller microcavities of 10-20 microm in diameter and 3-10 microm in depth located within the primary cavities, which we termed secondary. We asked whether a microcavity-rich scaffold had distinct bone-forming capabilities compared to a smooth one. To do so, mesenchymal stem cells derived from human dental pulp were seeded onto the two types of scaffold and monitored over time for cytoarchitectural characteristics, differentiation status and production of important factors, including bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF). We found that the microcavity-rich scaffold enhanced cell adhesion: the cells created intimate contact with secondary microcavities and were polarized. These cytological responses were not seen with the smooth-surface scaffold. Moreover, cells on the microcavity-rich scaffold released larger amounts of BMP-2 and VEGF into the culture medium and expressed higher alkaline phosphatase activity. When this type of scaffold was transplanted into rats, superior bone formation was elicited compared to cells seeded on the smooth scaffold.In conclusion, surface microcavities appear to support a more vigorous osteogenic response of stem cells and should be used in the design of therapeutic substrates to improve bone repair and bioengineering applications in the future

The value of the below-the-ankle level loop technique of foot artery reconstruction

\u2022 The pedal-plantar loop technique has been successfully applied in specialised vascular centers, showing its feasibility and safety. \u2022 However, this technique is not always feasible (15-20% of cases) due to anatomic variation of foot circulation of very challenging lesions in very tortuous arteries. \u2022 The technical key point is to advance step-by-step into thoses very narrow and tortuous arteries. \u2022 Progression with short injection througth the support catheter is mandatory. \u2022 The use of dedicated material is crucial

Physician-made fenestrated endografts versus chimney grafts

\u2022 Both techniques are off label and are indicated for patients unfit for open surgery and where other therapeutic options are not available. The techniques require excellent experience in standard EVAR and renal/visceral vessel catheterisation and grafting. \u2022 Chimney graft technique can be used for more proximal thoracoabdominal aneurysms. This technique seems to be easier and faster to perform. it is safer because of the possibility of retrieving all devices in case of access failure to target vessels. With this technique, there is less exposure to X-rays. \u2022 A physician-made fenestrated graft is more suitable anatomically and has the possible advantages of long-term durability of the technique in terms of graft patency and visceral perfusion. \u2022 Combination of the two techniques can reduce the complexity of multiple fenestrations as well as the risk of the gutters' endoleaks from multiple chimney grafts

Vascular Knowledge in Medieval Times was the Turning Point for the Humanistic Trend

AbstractObjectiveKnowledge of the history of our surgical specialty may broaden our viewpoint for everyday practice. We illustrate the scientific progress made in medieval times relevant to the vascular system and blood circulation, progress made despite prevailing religious and philosophical dogma.MethodsWe located all articles concerning vascular knowledge and historical reviews in databases such as MEDLINE, EMBASE and the database of abstracts of reviews (DARE). We also explored the database of the register from the French National Library, the French Medical Inter-University (BIUM), the Italian National Library and the French and Italian Libraries in the Vatican. All data were collected and analysed in chronological order.ResultsMedieval vascular knowledge was inherited from Greek via Byzantine and Arabic writings, the first controversies against the recognized vascular schema emanating from an Arabian physician in the 13th century. Dissection was forbidden and clerical rules instilled a fear of blood. Major contributions to scientific progress in the vascular field in medieval times came from Ibn-al-Nafis and Harvey.ConclusionVascular specialists today may feel proud to recall that once religious dogma declined in early medieval times, vascular anatomic and physiological discoveries led the way to scientific progress

Thirty-day Outcome of Delayed Versus Early Management of Symptomatic Carotid Stenosis

Background: The aim of this study was to compare outcomes of early (<15 days) versus delayed carotid endarterectomy (CEA) in symptomatic patients. Methods: All CEA procedures performed for symptomatic carotid stenosis between January 2006 and May 2010 were retrospectively reviewed. Postoperative mortality (within 30 days), stroke, and myocardial infarction (MI) rates were analyzed in the early and delayed CEA groups. Results: During the study period, 149 patients were included. Carotid revascularization was performed within 15 days after symptom onset in 62 (41.6%) patients and longer than 15 days after symptom onset in 87 (58.4%) patients. The mean time lapse between onset of neurological symptoms and surgery was 9.3 days (range 1-15) in the early surgery group and 47.9 days (range 16-157) in the delayed surgery group. Thirty-day combined stroke and death rates were, respectively, 1.7% and 3.5% in the early and the delayed surgery groups. Thirty-day combined stroke, death, and MI rates were, respectively, 1.7% and 5.9% in the early and the delayed surgery groups. Conclusion: During the study period, the reduction of the symptom-to-knife time in application to the carotid revascularization guidelines did not impact our outcomes suggesting that early CEA achieves 30-day mortality and morbidity rates at least equivalent to those of delayed CEA