iPSCs-based generation of vascular cells: reprogramming approaches and applications.

Recent advances in the field of induced pluripotent stem cells (iPSCs) research have opened a new avenue for stem cell-based generation of vascular cells. Based on their growth and differentiation potential, human iPSCs constitute a well-characterized, generally unlimited cell source for the mass generation of lineage- and patient-specific vascular cells without any ethical concerns. Human iPSCs-derived vascular cells are perfectly suited for vascular disease modeling studies because patient-derived iPSCs possess the disease-causing mutation, which might be decisive for full expression of the disease phenotype. The application of vascular cells for autologous cell replacement therapy or vascular engineering derived from immune-compatible iPSCs possesses huge clinical potential, but the large-scale production of vascular-specific lineages for regenerative cell therapies depends on well-defined, highly reproducible culture and differentiation conditions. This review will focus on the different strategies to derive vascular cells from human iPSCs and their applications in regenerative therapy, disease modeling and drug discovery approaches.

Hemashield Vascular Graft Is a Preferable Prosthetic Graft for Middle Hepatic Vein Reconstruction in Living Donor Liver Transplantation.

BACKGROUND Because of the supply shortage for homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. However, owing to the subsequent unavailability of ringed Gore-Tex grafts, we replaced them with Hemashield vascular grafts. This study aimed to compare the patency of Hemashield grafts with that of ringed Gore-Tex grafts. MATERIAL AND METHODS This was a retrospective double-arm study between the study group that used Hemashield grafts (n=63) and the historical control group that used ringed Gore-Tex grafts (n=126). RESULTS In the Gore-Tex and Hemashield groups, mean age was 53.1±6.2 and 54.3±10.4 years; model for end-stage liver disease score was 16.5±8.3 and 17.5±9.9; and graft-recipient weight ratio was 1.11±0.23 and 1.12±0.25, respectively. In the Gore-Tex graft group, V5 reconstruction was done in single (n=107, 84.9%), double (n=17, 13.5%), and none (n=2, 1.6%). V8 reconstruction was done in single (n=95, 75.4%), double (n=1, 0.8%), and none (n=30, 23.8%). In the Hemashield group, V5 reconstruction was done in single (n=43, 68.3%), double (n=19, 30.2%), and triple (n=1, 1.6%). V8 reconstruction was done in single (n=45, 71.4%), double (n=9, 14.3%), and none (n=9, 14.3%). One-year conduit patency rates in the Gore-Tex and Hemashield groups were 54.8% and 71.6%, respectively (p=0.048). CONCLUSIONS MHV reconstruction using Hemashield vascular grafts demonstrated higher short-term patency rates than those associated with ringed Gore-Tex vascular grafts. We suggest that the Hemashield vascular graft is one of the best prosthetic materials for MHV reconstruction.

Regenerative Therapy for Patients with Congenital Heart Disease.

Congenital heart disease (CHD) is the most common birth defect, affecting 1 in 100 babies. Among CHDs, single ventricle (SV) physiologies, such as hypoplastic left heart syndrome and tricuspid atresia, are particularly severe conditions that require multiple palliative surgeries, including the Fontan procedure. Although the management strategies for SV patients have markedly improved, the prevalence of ventricular dysfunction continues to increase over time, especially after the Fontan procedure. At present, the final treatment for SV patients who develop heart failure is heart transplantation; however, transplantation is difficult to achieve because of severe donor shortages. Recently, various regenerative therapies for heart failure have been developed that increase cardiomyocytes and restore cardiac function, with promising results in adults. The clinical application of various forms of regenerative medicine for CHD patients with heart failure is highly anticipated, and the latest research in this field is reviewed here. In addition, regenerative therapy is important for children with CHD because of their natural growth. The ideal pediatric cardiovascular device would have the potential to adapt to a child's growth. Therefore, if a device that increases in size in accordance with the patient's growth could be developed using regenerative medicine, it would be highly beneficial. This review provides an overview of the available regenerative technologies for CHD patients.

Applying value stream mapping techniques to eliminate non-value-added waste for the procurement of endovascular stents.

UNLABELLED: OJECTIVES: To eliminate non-value-adding (NVA) waste for the procurement of endovascular stents in interventional radiology services by applying value stream mapping (VSM). MATERIALS AND METHODS: The Lean manufacturing technique was used to analyze the process of material and information flow currently required to direct endovascular stents from external suppliers to patients. Based on a decision point analysis for the procurement of stents in the hospital, a present state VSM was drawn. After assessment of the current status VSM and progressive elimination of unnecessary NVA waste, a future state VSM was drawn. RESULTS: The current state VSM demonstrated that out of 13 processes for the procurement of stents only 2 processes were value-adding. Out of the NVA processes 5 processes were unnecessary NVA activities, which could be eliminated. The decision point analysis demonstrated that the procurement of stents was mainly a forecast driven push system. The future state VSM applies a pull inventory control system to trigger the movement of a unit after withdrawal by using a consignment stock. CONCLUSION: VSM is a visualization tool for the supply chain and value stream, based on the Toyota Production System and greatly assists in successfully implementing a Lean system.

The impact of stent design on proximal stent-graft fixation in the abdominal aorta: an experimental study.

OBJECTIVE: to study the proximal fixation of different aortic stent grafts in comparison to a hand-sewn anastomosis. DESIGN: experimental study. MATERIAL: the infrarenal aorta of 16 human cadavers were exposed, left in situ and transected 3 cm above the aortic bifurcation to mimic an infrarenal aortic neck. Stent grafts were deployed through a sheath 5 cm into the aorta. Ancure, Talent, Vanguard, Zenith and a Palmaz based stent graft were assessed. In addition a polyester graft was anastomosed to the aorta by running sutures. Distal force was applied to the grafts in increments of 0.5 Newton until the stent grafts were completely dislodged from the aorta. The displacement force (DF) was thereby determined. RESULTS: a force of 150 N (140-160) applied to the hand-sewn graft resulted in tearing of the aorta, without breakage of the sutures. The median displacement force was for Talent 4.5 N (1.3-5.5), Vanguard 9.0 N (3. 5-12), Ancure 12.5 N (12-14), Zenith 24 N (23-26.5) and Palmaz 25 N (17-25). Ballooning the stent after deployment improved fixation in some cases. CONCLUSIONS: a sutured anastomosis fixates a graft better than any stent design tested. Hooks and barbs improve the fixation of self-expandable stents. Balloon dilatation of the proximal stent after deployment might increase fixation further. Balloon expandable stents seem to provide good fixation without the use of hooks and barbs.