BACKGROUND:The appearance of biodigradable stents brings a new dawn for the fourth coronary intervention revolution. They not only can solve the problem of postoperative acute occlusion of blood vessels, but also can be completely absorbed after a certain time.
OBJECTIVE: To summarize the application status of biodegradable coronary stents.
METHODS:PubMed, CBM and embase were searched for articles related to biodegradable intravascular stents.
RESULTS AND CONCLUSION:Biodegradable polymer stents, biodegradable magnesium stents and biodegradable iron stents are currently the three major research biodegradable stent systems. Numerous clinical trials have demonstrated the long-term safety and reliability of the biological degradation stents, and in the near future they wil replace the existing drug-eluting stents as the primary means of percutaneous coronary intervention. Biodegradable stents currently stil have their limitations, which are reflected in the relationship between mechanical properties and degradation rate and cannot be applied to complicated coronary patients temporarily. It takes 6-12 months to restore normal physiological function of blood vessels, and it can be considered reasonable that degradation of stents is completed in 12-24 months. Poly(lactic-co-glycolic) produced by polylactic acid and polyglycolic acid is currently widely recognized as the stent’s framework. We can get a more appropriate balance between the mechanical properties of the stent and the degradation rate by adjusting the ratio of polylactic acid and polyglycolic acid. This stent not only has good mechanical properties, but also can be completely biodegradable after the restoration of normal function of blood vessels, which has a broad research space.

Objective:To assess the feasibility and safety of 2-staged hybrid technique for treating coronary artery disease (CAD) patients with multi-vessel lesions.
Methods: Our research included 2 groups:Hybrid group, CAD patients with left anterior descending artery (LAD) lesion or with other major epicardial vessel stenosis>70%who received 2-staged hybrid treatment in our hospital from 2012-03 to 2015-03 and Control group, CAD patients received elective conventional off-pump coronary artery bypass (OPCAB) by the same surgeon at meanwhile. n=91 in each group. The peri-operative conditions and complications were compared between two groups.
Results: Compared with Control group, Hybrid group had the shorter post-operative mechanical ventilation time (7.9 ± 4.8) h vs (21.6 ± 35.9) h, shorter ICU-stay time (29.6 ± 20.8) h vs (47.5 ± 38.3) h, all P<0.01 and less peri-operative blood transfusion (0.59 ± 1.48) U vs (2.82 ± 3.81) U, P<0.01. The post-operative complications of mortality, MI occurrence and delayed wound healing were similar between 2 groups, P>0.05.
Conclusion:2-staged hybrid technique is a safe, feasible and minimally invasive technique for treating CAD patients with LAD and multi-vessel lesions.

Objective To establish CRRT nursing quality evaluation index system based on the structure-process-outcome theory, so as to guide clinical nursing and evaluate CRRT nursing quality. Methods Based on structure-process-outcome theory,the evaluation index system was established by literature review,expert group discussion, Delphi method and semi-structural interviews with 10 nursing staff. Results The returning rates of questionnaires in the first and second round expert consultation were 94.29％(33/35) and 97.14％(34/35), respectively. The authority coefficient of the experts was 0.89, and the coordination coefficient of experts' opinion was 0.294. The program included 3 first indexes, 15 second index and 73 items. Conclusions The result of the study can provide evaluation for the clinical nursing operation.

Objective: To evaluate the effect of zinc ions on human umbilical vein endothelial cells biological functions. Methods: The primary human umbilical vein endothelial cells were cultured with the ECM medium, and cells were divided into 8 groups: the control group(routine culture,n=3), 20 μmol/L zinc group(20 μmol/L zinc chloride solution was added into the cell medium, n=3), 40 μmol/L zinc group(40 μmol/L zinc chloride solution was added into the cell medium, n=3),80 μmol/L zinc group(80 μmol/L zinc chloride solution was added into the cell medium, n=3), 100 μmol/L zinc group(100 μmol/L zinc chloride solution was added into the cell medium, n=3), 200 μmol/L zinc group(200 μmol/L zinc chloride solution was added into the cell medium, n=3),300 μmol/L zinc group(300 μmol/L zinc chloride solution was added into the cell medium, n=3), 500 μmol/L zinc group(500 μmol/L zinc chloride solution was added into the cell medium, n=3). The cell proliferation curve was derived from real time cell analysis (RTCA). The viability value was obtained via CCK-8 reagent, and the migration distance was tested by scratch-wound assay while the adhesion function was detected by RTCA. Results: (1)After 18 hours, RTCA showed that the proliferation cell indexes were 4.5±0.6, 3.7±0.4, 3.6±0.3, 2.5±0.4, and 2.5±0.4 in the 20, 40, 80, 100, and 200 μmol/L zinc groups, as compared with 3.5±0.3 in the control group (all P<0.05). Proliferation cell indexes were 0 in both of the 300 μmol/L and 500 μmol/L zinc groups. (2)After 96 hours, the viability were 1.21±0.05, 1.10±0.03, 0.99±0.05, 0.62±0.02, 0.45±0.04, 0.11±0.01, and 0.12±0.06, respectively in the 20, 40, 80, 100, 200, 300, and 500 μmol/L zinc groups, as compared with 0.75±0.05 in the control group (all P<0.05). (3)After 12 hours, the migration distances were (0.56±0.11),(0.96±0.07),(0.49±0.02), and (0.29±0.01)mm in the 20, 40, 80, and 100 μmol/L zinc groups, as compared with (0.24±0.04)mm in the control group (all P<0.05). (4)After 18 hours, the adhesion cell index were 0.40±0.05, 0.31±0.01, 0.38±0.05, and 0.40±0.03 in the 20, 40, 80, and 100 μmol/L zinc groups, as compared with 0.24±0.04 in the control group (all P>0.05). Conclusions Zinc ions at lower concentration (≤80 μmol/L) can promote proliferation, viability and migration of human umbilical vein endothelial cells, but the adhesion function was not significantly affected by zinc ions. Zinc ions at higher concentration (≥200 μmol/L) can inhibit the cellular function of the human umbilical vein endothelial cells.

The objectives of this study were to prepare pitavastatin-loaded poly lactic-co-glycolic acid nanoparticles(PLGA), to characterize their pharmaceutical properties, to conduct in vitro drug-release from the nanoparticles, and to observe the effects on the proliferation of endothelial progenitor cells. Both pitavastatin-loaded PLGA and blank PLGA nanoparticles were prepared using emulsion-solvent diffusion method with PLGA being carrier materials. Morphology of the nanoparticles was observed by scanning electron microscopy(SEM), and particle size was analyzed by laser nanometer particle size analyzer. The drug loading and encapsulation efficiency were assayed using high-performance liquid phase. Impact of blank and pitavastatin-loaded nanoparticles on the viability of endothelial progenitor cells was investigated by CCK8 method. Pitavastatin-loaded PLGA nanoparticles exhibited the structure with spherical shape, smooth surface and average diameter of(230. 1±45)nm. The drug loading capacity and encapsulation efficiency were(10. 00±1. 83)% and(35. 54±5. 40)%, respectively. In vitro sustained-release of pitavastatin from the nanoparticles was found. The blank PLGA nanoparticles had no effect on the viability of the endothelial progenitor cells in different concentrations. Compared with pitavastatin group, pitavastatin-loaded nanoparticles(0. 01 μmol/L, 0. 1 μmol/L)had more effects on the proliferation of endothelial progenitor cells. In conclusion, emulsion-solvent diffusion method is applicable in preparation of pitavastatin-loaded PLGA nanoparticles with good shape and sustained-release of interest. Pitavastatin-loaded nanoparticles could significantly improve proliferation of the endothelial progenitor cells.

Objective    To analyze the feasibility of using triangular-sail technique that allows intermittent two-lung ventilation during minimally invasive coronary artery bypass grafting (MICS CABG). Methods    The clinical data of 207 patients with MICS CABG in our cardiac center from January 2019 to November 2020 were retrospectively analyzed. These patients were divided into two groups. A group OLV included 111 patients who underwent one-lung ventilation during surgery, while a group TLV included 96 patients who underwent intermittent two-lung ventilation. The triangular-sail technique was used in the group TLV. This simple technique isolated the operative field from lung lobes with the traction of pericardial adipose tissue. The preoperative data and perioperative clinical data of the two groups were compared and analyzed. Results    There was no statistical difference in basic preoperative data between the two groups. The operation time in the OLV group was shorter than that in the TLV group (296.7±57.3 min vs. 334.1±87.0 min, P=0.000), and the duration of postoperative mechanical ventilation and ICU stay were not statistically different between the two groups. There was also no statistical difference in the incidence of pneumothorax or atelectasis between the two groups. Conclusion    The triangular-sail technique is simple and easy to implement. The technique allows intermittent two-lung ventilation during MICS CABG procedure.

Objective    To investigate the safety and effectiveness of the multi-artery graf tstrategy for coronary bypass (MICS-CABG) with small incision in the left chest, and to provide experience for the promotion of this technique. Methods    The clinical data of 64 patients with MICS-CABG in Department of Cardiac Surgery of Peking University Third Hospital from December 2015 to November 2019 were retrospectively analyzed. There were 54 males and 10 females, aged 36-77 (61.1±8.7) years. The left lateral thoracic incision (5-8 cm) was made through the 5th intercostal incision, and the operation was performed under off-pump CABG. With the help of the chest wall suspension device and the heart fixator, the proximal anastomosis of the ascending aorta, anastomosis of the target vessels of the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) systems were completed. The number of grafts was 2-4 (2.3±0.5) including 2 grafts in 45 patients, 3 grafts in 17 patients and 4 grafts in 2 patients. Three patients were treated with percutaneous intervention (PCI) hybridization and 62 patients were treated with total artery bypass graft. Coronary angiography was performed within 7 days after the operation to evaluate the graft patency rate. The incidence of major adverse cardiac and cerebrovascular events (MACCE) was recorded in the follow-up. The MACCE rate was calculated by Kaplan-Meier method. Results    None of the patients was transferred to thoracotomy and no intra-aortic balloon counterpulsation (IABP) or extracorporeal membrane oxygenation (ECMO) was used during the operation.  Incision infection was in 1 patient and reoperation in 2 patients (all were postoperative hemorrhage). Within 30 days after surgery, MACCE occurred in 1 patient, including 1 patient of non-fatal myocardial infarction. The overall patency rate of angiography bypass was 96.2%, and the patency rate of anterior descending branch bypass was 98.2%. Follow-up was performed from 12 to 60 months (median follow-up time was 28 months). The loss rate was 7.8% (5/64). The incidence of MACCE was 84.9% (95%CI 79.5%-90.3%). Conclusion    The MICS-CABG can achieve completed re-vascularization and totally artery-CABG and the short-term and medium-term clinical results of the operation are good.