Comparison and enlightenment of cardiothoracic residency training between China and the United States / 中华医学教育探索杂志

Through the comparison of the residency training system between China and the United States in pre-training educational background, training policy and post-training career path, it is concluded that the cardiothoracic surgery residency training in the United States has a high admission threshold, long training cycle and high education cost, but it also has the advantages of professional management, outstanding specialty characteristics and perfect evaluation system, which are suitable for the training of cardiothoracic surgeons. However, the current residency training of cardiothoracic surgery in China needs to be further improved. Learning from the advantages of the United States residency training system, we can formulate a more reasonable and professional residency training program according to Chinese own characteristics, so as to train excellent cardiothoracic surgeons for our country.

Clinical application of 3D printing-assisted extracorporeal fenestration in TEVAR surgery / 中华胸心血管外科杂志

Objective:To investigate the effectiveness and feasibility of 3D printing-assisted extracorporeal fenestration techniques in thoracic aortic endoluminal repair.Methods:Retrospectively analyzed the clinical data of patients who underwent endovenous repair of the thoracic aorta with the application of 3D printing technology-assisted extracorporeal windowing in the Department of Cardiovascular Surgery, Wuhan University Hospital from January 2019 to May 2021, and analyzed the surgical results as well as the occurrence of perioperative complications.Results:A total of 10 patients with a mean age of(53.3±15.7) years were included, including 4 cases of complex B aortic coarctation, 5 cases of thoracic aortic aneurysm and 1 case of abdominal aortic aneurysm. All patients in this group underwent endoluminal repair of the thoracic aorta with 3D printing assisted extracorporeal fenestration, including 1 case of PCI performed at the same time. There were no postoperative complications and no perioperative deaths.Conclusion:3D printing technology assisted extracorporeal fenestration and endoluminal aortic repair can accurately position aortic stents for fenestration, optimise endoluminal treatment options and improve patient prognosis.

Treatment strategies in ischaemic left ventricular dysfunction: a network meta-analysis.

OBJECTIVES: The optimal revascularization strategy for patients with ischaemic left ventricular systolic dysfunction (iLVSD) remains controversial. We aimed to compare percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical therapy (MT) in a network meta-analysis. METHODS: All randomized controlled trials and observational studies comparing any combination of PCI, CABG and MT in patients with iLVSD were analysed in a frequentist network meta-analysis (generic inverse variance method). Primary outcome was mortality at longest available follow-up. Secondary outcomes were cardiac death, stroke, myocardial infarction (MI) and repeat revascularization (RR). RESULTS: Twenty-three studies were included (n = 23 633; 4 randomized controlled trials). Compared to CABG, PCI was associated with higher mortality [incidence rate ratio (IRR) 1.32, 95% confidence interval (CI) 1.13-1.53], cardiac death (IRR 1.65, 95% CI 1.18-2.33), MI (IRR 2.18, 95% CI 1.70-2.80) and RR (IRR 3.75, 95% CI 2.89-4.85). Compared to CABG, MT was associated with higher mortality (IRR 1.52, 95% CI 1.26-1.84), cardiac death (IRR 3.83, 95% CI 2.12-6.91), MI (IRR 3.22, 95% CI 1.52-6.79) and RR (IRR 3.37, 95% CI 1.67-6.79). Compared to MT, PCI was associated with lower cardiac death (IRR 0.43, 95% CI 0.24-0.78). CABG ranked as the best revascularization strategy for mortality, cardiac death, MI and RR; MT ranked as the strategy associated with the lowest incidence of stroke. Left ventricular ejection fraction, year of study, use of drug-eluting stents did not affect relative treatment effects. CONCLUSIONS: CABG appears to be the best therapy for iLVSD, although mainly based on observational data. Definitive randomized controlled trials comparing CABG and PCI in iLVSD are required. PROSPERO REGISTRATION ID: 132414.

Open Repair of Descending Thoracic and Thoracoabdominal Aortic Aneurysms: A Meta-Analysis.

BACKGROUND: Contemporary outcomes of open repair of thoracoabdominal aortic aneurysms (TAAAs) and descending thoracic aortic aneurysms (DTAs) have not been analyzed in an inclusive meta-analysis. METHODS: After a systematic literature search, studies from 2008 to 2018 reporting outcomes of open repair of DTAs or TAAAs were pooled in a single-arm meta-analysis performed using the generic inverse variance method. Primary outcome was operative mortality. Secondary outcomes were late mortality, postoperative stroke, permanent and temporary spinal cord injury, renal failure, respiratory failure, and myocardial infarction. RESULTS: Fifty-four studies with 12,245 patients were included. Pooled operative mortality for open repair was 10.4% (95% confidence interval [CI], 8.3-12.8): 6.6% (95% CI, 3.7-11.6) for DTA and 10.5% (95% CI, 7.5-14.5) for TAAA. Pooled incidence rate of late mortality was 0.6% (95% CI, 0.5-0.8) per person-year. Pooled rates for postoperative outcomes were 4.9% (95% CI, 3.9-6.1) for stroke; 5.7% (95% CI, 4.3-7.5) and 3.0% (95% CI, 2.1-4.2) for permanent and temporary spinal cord injury, respectively; 13.2% (95% CI, 9.9-17.3) for renal failure; 23.3% (95% CI, 17.5-30.4) for respiratory failure; and 2.7% (95% CI, 1.8-4.1) for myocardial infarction. At metaregression, year of publication, use of the clamp-and-sew technique, and use of the cerebrospinal fluid drain were associated with lower operative mortality. Ruptured aneurysms were associated with higher operative mortality. CONCLUSIONS: Despite improvement, open repair of DTAs and TAAAs continues to be associated with a considerable risk for operative death and perioperative complications. Use of the cerebrospinal fluid drain is associated with better outcomes.

Single-center effect analysis of clinical application of marginal donor heart / 中华胸心血管外科杂志

Objective:To retrospectively analyze the experience of our center in the use of marginal donor heart, and to explore the principle of use and risk control of marginal donor heart.Methods:A total of 31 patients with end-stage heart disease underwent orthotopic heart transplantation in our center from January 2018 to December 2018, including 28 cases of pure heart transplantation, 2 cases of combined heart-lung transplantation, and 1 case of combined heart-kidney transplantation. 26 of the 31 cases were marginal donor hearts. These patients were all anastomosed by a double lumen method.Results:The rates of postoperative use of ECMO, IABP and acute rejection were zero in this study. The time of cardiopulmonary bypass in the marginal donor group was significantly longer compared with the conventional donor group( P<0.05), but there was no significant difference between the two groups in terms of hospitalization time, mechanical ventilation time, ICU stay time, abnormal rate of ECG, LVEF and blood biochemical indexes(all P>0.05). The postoperative follow-up rate was 100% in the two groups. One case of combined heart-lung transplantation in the marginal donor group died of multiple organ failure in the first month after surgery. During the postoperative follow-up period, the incidence of moderate to severe tricuspid regurgitation and the incidence of recurrent heart failure were zero in the two groups. There was no significant difference in the incidence of arrhythmia, LVEF, infection and blood biochemical parameters. Conclusion:The application of marginal donor heart has no significant effect on the short-term survival rate and recovery of patients after heart transplantation, but the long-term effect needs further follow-up.

The current state of animal models in research: A review.

Animal models have provided invaluable information in the pursuit of medical knowledge and alleviation of human suffering. The foundations of our basic understanding of disease pathophysiology and human anatomy can largely be attributed to preclinical investigations using various animal models. Recently, however, the scientific community, citing concerns about animal welfare as well as the validity and applicability of outcomes, has called the use of animals in research into question. In this review, we seek to summarize the current state of the use of animal models in research.

Clinical analysis of type A aortic dissection with acute lower limb ischemia / 中华胸心血管外科杂志

Objective To summarize the clinical experience and efficacy of surgical treatment for Stanford type A aortic dissection leading to acute lower limb ischemia.Methods From January 2014 to January 2018,12 patients with severe lower limb ischemia caused by acute type A aortic dissection were treated with Suns surgery.Among them,11 patients were treated with restoration of lower limb blood supply preferentially,including 10 cases of femoral artery bypass and 1 case of abdominal aorta-iliac artery stent graft implantation.Another case was treated with ascending aorta-femoral artery bypass after Sung surgery.Results 3 cases died of ischemia and necrosis of the lower extremities.Two of them died of multiple organ failure due to amputation and one died of low cardiac output due to refractory acidosis.Acute renal failure performed bedside CRRT in 5 patients and ECMO in 1 patient.The remaining 9 patients were discharged from the hospital and the symptoms of lower limb ischemia disappeared.After an average follow-up of 23 months,the re-examination of the aorta CTA showed that the bypass artery was unobstructed and the distal femoral artery was well developed.One patient infecting vascular prosthesis was cured by taking out the unit.Conclusion For acute lower limb ischemia caused by type A aortic dissection,blood flow of lower extremities should be restored as soon as possible to reduce mortality and complications.Femoral artery bypass and abdominal aorta-iliac arterial repair are simple and effective in reconstructing lower limb blood supply.

Using mice immature dendritic cells to induce the differentiation of allogenic naive T cells in vitro / 中华器官移植杂志

Objective To explore the differentiation of allogeneic naive T cells to regulatory T cells (Tregs) and T helper (TH) 1/2/17 cells by coculture with bone marrow-derivedimmature dendritic cells (irnDC).Method Bone marrow-derived imDC were cultivated from Balb/c mice.Lipopolysaccharide-stimulated DC were harvested as mature dendritic cells (mDC) and unstimulated cells were collected as imDC.Then irnDC or mDC were cocultured with allogeniec naive T cells,respectively.TH1 cytokines [interferon-γ (IFN-γ) and interleukin (IL)-2],TH2 cytokines (IL-4 and IL-10),and TH17 cytokine (IL-17) of co-cultured cells were detected by enzyme linked immunospot assay.CD4+ Forkhead box p3 (FoxP3) + Treg proportion in CD4+ cells in the co-cultured system with IL-2 and transforming growth factor-β1 (TGF-β1) was analyzed by flow cytometry.Result As compared with mDC,na(i)ve T cells cocultured with imDC secreted much less IFN-γ (11.67 ± 2.18 vs.182.00±23.71,P＜0.01),IL-2 (26.67±2.96 vs.318.30± 18.62,P＜0.01),IL-4 (17.00±3.78 vs.45.33±3.48,P＜0.01),IL-10(7.00±1.00vs.158.70±10.90,P＜0.001) and IL-17 (0.66 ± 0.33 vs.238.30 ± 24.39,P＜0.001).Furthermore,imDC induced more CD4+ FoxP3+ Tregs than mDC after adding IL-2 and TGF-β1 in the coculture system for 7 days (22.70 ± 1.53 ％ vs.5.42 ± 1.27％,P＜0.01).Conclusion imDC are more effective to induce na ve T cells to Tregs,but not differentiate to TH 1/TH 2/TH 17 cells.These findings provide in vitro experimental evidence for induction of transplant tolerance by adoptive transfer of imDC.

Resistance of rat adipose-derived stem cells to human xenoantibody-dependant complement-mediated lysis and its mechanism / 中华器官移植杂志

Objective To investigate whether rat adipose-derived stem cells (rASCs) could resist human xenoantibody-dependent complement-mediated lysis and to explore its possible mechanisms.Method SD rat ASCs were isolated,rASCs at passage 2 to 8 were used for the following studies and rat lymphocytes were harvested as control cells.α-Gal expression was detected by flow cytometry.After incubation of rASCs with 20％ normal human serum (NHS) or heat inactivated normal human serum (HINHS),flow cytometry was used to detect cytotoxicity,IgG or IgM binding,and C3c,C4c and C5b-9 deposition.Result We successfully established the method to isolate and culture rASCs.The morphology of rASCs remained unchanged after passages.rASCs were positive for tell surface markers of CD44 and CD90,while negative for CD45 and MHC-Ⅱ.As compared with rLCs,rASCs significantly resisted human natural antibody and complement-mediated lysis when incubated with 20％ NHS in vitro (20.42％ ± 2.80％ vs 51.84％ ± 6.70％,P ＜ 0.01).Mechanistically,rASCs expressed lower level of α-Gal (13.97 ± 0.33 vs.24.47 ± 3.03,P＜0.05),which was correlated with decreased binding of human xenoreactive IgG and IgM (IgM:9.4 ± 2.0 vs.107.2± 4.8,P＜0.01; IgG:5.73 ± 1.0 vs.27.49 ± 3.9,P＜0.01) and reduced deposition of complements C3c,C4c and C5b-9 (C3c:294.6 ± 38.02 vs.1924 ± 509.4,P＜0.05; C4c:35.23 ± 3.1vs.177.3 ± 37.17,P＜0.05; C5b-9:5.63 ± 1.74 vs.37.05 ± 7.4,P＜0.01).Conclusion These data demonstrated that the resistance of rASCs to human xenoantibody and complement-mediated lysis is associated with low expression of xenoantigen a-Gal and inhibition of MAC (membrane attack complex) formation.

Carbon monoxide-releasing molecule CORM-2 protects against renal ischemia-reperfusion injury in mice / 中华器官移植杂志

Objective To investigate if the administration of CORM-2 can provide protection against renal ischemia-reperfusion injury (IRI).Method Murine renal ischemia was induced by clamping left renal pedicles for 40 min with vascular micro damps at 32 C,then the contralateral kidney was removed.CORM-2 or vehicle was administered via intravenous infusion 1 h before the onset of ischemia.The blood plasma and renal samples were obtained at 24 h after reperfusion to assess renal function and cellular injury.Plasma Cr and BUN levels,HE and TUNEL were performed to estimate the magnitude of renal damage.Kidneys were retrieved from indicated animals at various time points after renal IRI,and the sections were prepared for histological evaluation.MPO staining procedures were performed to assess the neutrophils infiltration in the renal IRI.Besides,Immunofluorescent stain of TNF-α was performed on the kidneys which were retrieved from indicated animals to determine the production of inflammatory mediators in renal I/R.Results The plasma Cr and BUN were significantly increased at 24 h after reperfusion in IRI control mice,and CORM-2 treatment could markedly diminish the increase of plasma Cr and BUN in mice subjected to I/R.In parallel,histological analysis demonstrated that CORM2 treatment markedly reduced apoptosis of the renal tubular epithelium cells and hemorrhage.IRI caused marked infiltration and accumulation of the MPO-positive neutrophils in renal interstitium.Administration of CORM-2 before ischemia dramatically inhibited neutrophils infiltration as compared with IRI or iCORM-2 group.Furthermore,we confirmed that CORM-2 markedly decreased production of TNF-α.Conclusion Carbon monoxidereleasing molecule CORM-2 could ameliorate inflammation to protect against the renal IRI in mice.

Prolongation of islet allograft survival in rats by cotransplantion with xenogenetic neonatal porcine Sertoli cells / 中华器官移植杂志

Objective To investigate whether cotransplant with xenogenetic neonatal porcine Sertoli cells (NPSCs) could prolong rat islet allograft survival and its mechanisms.Methods 1500 islets equivalent quantity (IEQ) and 1×10~7 NPSCs were implanted under renal capsule of diabetic Wistar rats.Islets implanted alone were used as control group (n=6);islets co-transplanted with NPSCs under left renal capsule of recipients served as experimental group (n=6);meanwhile,islets and NPSCs implanted into the different sides of kidneys were used as another control grouP(n=4).Blood glucose level was measured everyday.The graft-bearing kidneys at the time of rejection were Results Co-transplantation with NPSCs to the same site significantly prolonged islet allograft survival (mean survive time,16.3±1.4 days vs.5.7±1.0 days in islet transplant alone control group,P<0.05).In contrast,transplantation with NPSCs and islets separately did not prolong the islet allograft survival (5.3±0.5 days).HE staining showed plenty of local infiltrated lymphocytes in the transplanted site of the eontrol group.which were demonstrated as mainly CD3+ T cells by immunopathology.The local expression of Bcl-2 was markedly elevated in co-transplantation group as compared with the other 2 groups,while there were no significant differences in the HO-1 expression among these groups.Conclusion Co-transplantation with xenogenic NPSCs can significantly prolong islet allograft survival in rats.The immunoprotective mechanism may be associateel with the inhibition of lymphocyte infiltration and the enhancement of the local expression of protective gene Bcl-2.