RESUMO
Muscle necrosis and angiogenesis are two major challenges in the treatment of lower-limb ischemic diseases. In this study, a triple-functional Sr/Si-containing bioceramic/alginate composite hydrogel with simultaneous bioactivity in enhancing angiogenesis, regulating inflammation, and inhibiting muscle necrosis was designed to treat lower-limb ischemic diseases. In particular, sodium alginate, calcium silicate and strontium carbonate were used to prepare injectable hydrogels, which was gelled within 10 min. More importantly, this composite hydrogel sustainedly releases bioactive Sr2+ and SiO3 2- ions within 28 days. The biological activity of the bioactive ions released from the hydrogels was verified on HUVECs, SMCs, C2C12 and Raw 264.7 cells in vitro, and the therapeutic effect of the hydrogel was confirmed using C57BL/6 mouse model of femoral artery ligation in vivo. The results showed that the composite hydrogel stimulated angiogenesis, developed new collateral capillaries, and re-established the blood supply. In addition, the bioactive hydrogel directly promoted the expression of muscle-regulating factors (MyoG and MyoD) to protect skeletal muscle from necrosis, inhibited M1 polarization, and promoted M2 polarization of macrophages to reduce inflammation, thereby protecting skeletal muscle cells and indirectly promoting vascularization. Our results indicate that these bioceramic/alginate composite bioactive hydrogels are effective biomaterials for treating hindlimb ischemia and suggest that biomaterial-based approaches may have remarkable potential in treating ischemic diseases.
RESUMO
Background: Currently, the optimal technique to revascularize the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) remains controversial. Our study seeks to characterize early and late clinical results and to assess the advantages and disadvantages of endovascular vs. surgical strategies for the preservation of LSA. Methods: PubMed, Embase and Cochrane Library searches were conducted under the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analyses) standards. Only literature published after January 1994 was included. Studies reporting on endovascular revascularization (ER), surgical revascularization (SR) for LSA preservation were included. 30-day mortality and morbidity rates, restenosis rates, and rates of early and late reintervention are measured as outcomes. Results: A total of 28 studies involving 2,759 patients were reviewed. All articles were retrospective in design. Single-arm analysis found no significant statistical differences in ER vs. SR in terms of 30-day mortality and perioperative complication rates. The mean follow-up time for the ER cohort was 12.9 months and for the SR cohort was 26.6 months, respectively. Subgroup analysis revealed a higher risk of perioperative stroke (4.2%) and endoleaks (14.2%) with the chimney technique compared to the fenestrated and single-branched stent approaches. Analysis of the double-arm studies did not yield statistically significant results. Conclusion: Both ER and SR are safe and feasible in the preservation of LSA while achieving an adequate proximal landing zone. Among ER strategies, the chimney technique may presents a greater risk of neurological complications and endoleaks, while the single-branched stent grafts demonstrate the lowest complication rate, and the fenestration method for revascularization lies in an intermediate position. Given that the data quality of the included studies were relatively not satisfactory, more randomized controlled trials (RCTs) are needed to provide convincing evidence for optimal approaches to LSA revascularization in the future.