Selective coronary vein bypass graft improves outcomes of patients with right coronary artery lesion.

Background: The benefits of selective coronary vein bypass grafting (SCVBG) for patients with severe diffuse lesions of the right coronary artery (RCA) who are unsuitable for coronary endarterectomy (CE) are unclear. Methods: We recruited patients with diffuse lesions of the RCA undergoing coronary artery bypass surgery between January 2015 and December 2018 and matched SCVBG and CE patients on propensity score (PS). We evaluated the degree of single-stenosis in the RCA, incidence of perioperative myocardial infarction (MI) and major adverse cardiovascular and cerebrovascular events (MACCE), influencing factors of perioperative MACCE, long-term survival rate, and long-term MACCE incidence. Results: Overall, 430 patients were enrolled: 344 (80%) underwent CE and 86 (20%) underwent SCVBG (n=78 and n=64, respectively, after PS matching). The incidence of perioperative MI and MACCE were significantly lower in the SCVBG group (5.1% vs. 1.5%, P<0.05; and 10.2% vs. 4.7%, P<0.05). When the vascular flow rate of the graft anastomosed to RCA in the SCVBG group was above 100 mL/min, the incidence of perioperative MACCE significantly increased [odds ratio (OR): 1.94, 95% confidence interval (CI): 1.42-2.03]. Choosing the bilateral internal mammary artery for SCVBG reduced the incidence of perioperative MACCE (OR: 0.82, 95% CI: 0.68-0.92). There was no significant difference in the rates of long-term survival or MACCE between the two groups before or after PS matching (P>0.05). Conclusions: SCVBG is an acceptable surgical intervention for patients with severe diffuse RCA lesions.

New strategy of using double-network hydrogel extravascular stent for preventing venous graft restenosis after coronary artery bypass grafting.

OBJECTIVE: Effective therapies for the prevention of vein graft failure, which frequently occurs in coronary artery bypass grafting (CABG) due to intimal hyperplasia (IH), are still lacking. Here, we investigated the effects of the perivenous application of double-network hydrogel on vein grafts in carotid artery bypass grafting in a rabbit model. METHODS: Healthy New Zealand white rabbits were randomized into the following groups: no graft, graft, or graft + Double-network hydrogel external stent (DNHES). The rabbits' carotid artery was bypassed via the jugular vein. Double-network hydrogel external stent was wrapped around the jugular graft after the anastomoses were completed. Blood flow parameters and tissue histology of the vein grafts were evaluated. RESULTS: Compared with the untreated vein grafts at 12 weeks after the surgery, the DNHES significantly improved graft flow, attenuated intimal and medial thickening, reduced the anti-proliferating cell nuclear antigen proliferation index of the vein grafts, decreased the mRNA and protein expression of Mitogen-Activated Protein Kinase (MAPK) and Transforming Growth Factor-ß (TGF-ß), and increased the mRNA and protein expression of endothelial Nitric Oxide Synthase (eNOS). CONCLUSION: The perivenous application of DNHES exerts beneficial effects on vein grafts, reduces the inflammatory response in carotid artery bypass grafting in a rabbit model, and appears to be a safe and promising strategy to prevent vein graft failure.

Comparison of the mid-term clinical efficacy and short-term complications of Y-type coronary artery bypass grafting and sequential bypass grafting of the great saphenous vein: a retrospective cohort study.

Background: This study sought to compare and evaluate the clinical efficacy and safety of Y-type coronary artery bypass grafting (CABG) and sequential CABG. However, the prognosis and complication rate of the two treatments are different. Therefore, we need to systematically compare the efficacy and safety of the two surgical schemes. Methods: A total of 112 patients who underwent Y-type CABG and 113 patients who underwent sequential CABG were selected from January 2020 to December 2020. The patients undergoing Y-type CABG of the great saphenous vein (SV) were classified as the experimental group, and those undergoing sequential anastomosis were classified as the control group. The intraoperative blood flow at each anastomotic site of the venous sequential CABG, left ventricular ejection fraction (LVEF), and left ventricular diastolic diameter (LVEDD) at the end of 3 months, 6 months, and 1 year after surgery, the incidence rate of major adverse cardiovascular events, and coronary angiography (CAG) after readmissions due to similar symptoms were compared between the 2 groups. The bridging vascular blockage rate was also determined. Results: There was no significant difference in cardiac function between the 2 groups in the short term, and the incidence of major adverse cardiovascular events in the 2 groups mainly occurred in the middle-postoperative period (1 year after surgery) or later. There was no statistical difference in the intraoperative real-time blood flow measurements at each anastomosis of the venous bridge between the 2 groups. Compared to the control group, the LVEF of the experimental group was significantly increased at the 1-year follow-up point (51.6±5.1 vs. 67.6±5.6, P=0.001). During the operation of Y-type coronary artery bypass grafting, the incidence of major adverse cardiovascular events, vascular bridge, and anastomotic blockage were significantly decreased (16 vs. 39, P=0.023). Conclusions: Large SV Y-type CABG can improve postoperative left heart function and reduce the incidence of postoperative adverse events, which may be of great significance for improving the postoperative mid-term survival rate of patients.

The main trunk of RCA may be the best choice of sequential vein graft distal end-to-side anastomosis.

OBJECTIVE: The purpose of this study was to investigate the effect of different anastomotic positions on the early patency of the distal end-to-side anastomosis of sequential saphenous vein grafts (SVG) in off-pump coronary artery bypass grafting (OPCAB). METHODS: A total of 259 patients who underwent OPCAB between August 2014 and August 2019 and presented for coronary computed tomography angiography (CCTA) to evaluate graft patency at 1 year post-OPCAB were analyzed. There are two kinds of distal end-to-side anastomosis of SVG, to posterior descending artery (PDA) and main trunk of right coronary artery (RCA). In all, 1044 distal coronary anastomoses on 518 grafts which included 180 left internal mammary artery (LIMA) grafts, individual 79 SVG and 259 sequential SVG were assessed using CCTA. The blood flow (BF), pulsatility index (PI), and patency of every anastomosis were recorded. Besides, comprehensive data of SV-PDA and SV-RCA patients was also compared. RESULTS: The mean BF of SV-RCA was significantly higher than that of SV-PDA (31.71 ± 18.60 vs 22.62 ± 14.48, p = 0.001), and the PI value of SV-RCA was significantly lower than that of SV-PDA (2.57 ± 1.17 vs 3.50 ± 1.69, p = 0.001). The patency of RCA system was significantly lower than that of the LAD and the left circumflex system (79.25% vs 90.13%, 90.23% respectively, p = 0.001). In sequential SVG, the patency of SV-PDA was significantly lower than that of SV-RCA (74.01% vs 86.59%, p = 0.001). Although, there was no significant difference in left ventricular ejective fraction, the left ventricular end-diastolic diameter (LVDd) in SV-PDA group was significantly larger than that in SV-RCA (52.67 ± 8.72 mm vs 47.34 ± 7.55, p = 0.001). In addition, the target vessel diameter in SV-PDA group was smaller than that in SV-RCA group (1.52 ± 0.41 mm vs 3.17 ± 0.88 mm, p = 0.001). CONCLUSION: The early patency of sequential SVG end to RCA after OPCAB is generally superior to that of to PDA, especially for patients with large LVDd.

NIK-SIX1 signalling axis regulates high glucose-induced endothelial cell dysfunction and inflammation.

Endothelial dysfunction and inflammation are the main manifestations of diabetes-associated atherosclerosis. This paper studied the roles of NF-κB-inducing kinase (NIK) and sine oculis homeobox homolog 1 (SIX1) in regulating high glucose-induced endothelial dysfunction and inflammation. The expression of NIK and SIX1 in human umbilical vein endothelial cells (HUVECs) was silenced by transfection with the specific shRNAs. HUVECs exposed to high glucose were considered as a cell model of endothelial dysfunction. Expression of NIK and SIX1 following transfection was measured by qRT-PCR and western blotting analysis. The proliferation, migration, and inflammation of HUVECs were evaluated by EdU staining, scratch test, ELISA, and western blotting. High glucose (30 mM) significantly decreased the proliferation and migration of HUVECs. High glucose-induced the expression of adhesion molecules VCAM-1 and ICAM-1. Moreover, high glucose increased the release of IL-1ß, IL-6, TNF-α, and MCP-1. Transfection of cells with NIK shRNA significantly reversed the toxic effects of high glucose on HUVECs. Of contrast, SIX1 shRNA accelerated the effects of high glucose on HUVECs. NIK shRNA inhibited the accumulation of RelA, RelB, and p52. Meanwhile, NIK shRNA led to SIX1 downregulation which further induced the activation of the NF-κB pathway. NIK-SIX1 signalling axis was suggested to be critical in the regulation of high glucose-induced endothelial dysfunction and inflammation. SIX1 may function as an immunological gatekeeper to control the excessive inflammation mediated by NIK in diabetes-associated atherosclerosis.

Collagen External Scaffolds Mitigate Intimal Hyperplasia and Improve Remodeling of Vein Grafts in a Rabbit Arteriovenous Graft Model.

Objectives. The aim of this study was to test the effects of collagen external scaffold (CES) in intimal hyperplasia of vein grafts and explore its underlying mechanisms. Methods. Thirty-six New Zealand white rabbits were randomized into no-graft group, graft group, and CES group. The rabbit arteriovenous graft model was established. In CES group, the vein graft was wrapped around with CES. The hemodynamic parameters of vein grafts were measured intraoperatively and 4 weeks after operation by ultrasonic examination. Histological characteristics of vein grafts were also evaluated 4 weeks later. The mRNA and protein levels of proliferating cell nuclear antigen (PCNA), active cleaved-caspase-3 (ClvCasp-3), and smooth muscle 22 alpha (SM22α) were measured 4 weeks later by quantitative real-time PCR and western blot. Results. CES significantly improved the hemodynamic stability of vein grafts, with higher blood velocity and blood flow. Similarly, CES also markedly mitigated intimal hyperplasia and inhibited dilatation of vein grafts. In CES group, the upexpression of PCNA and ClvCasp-3 and the downexpression of SM22α were inhibited. Conclusion. CES exerts beneficial effects in mitigating intimal hyperplasia and improving remodeling of autogenous vein grafts, which may be associated with reducing the proliferation and apoptosis and preserving the phenotype of VSMCs.

Bipolar radiofrequency ablation in the treatment of left ventricular aneurysm with ventricular arrhythmias guided by CARTO mapping system: A randomized controlled trial / 中国胸心血管外科临床杂志

@#Objective    To evaluate the efficacy and clinical significance of bipolar radiofrequency ablation in the treatment of left ventricular aneurysm with ventricular arrhythmias guided by CARTO mapping system. Methods    From September 2009 to December 2015, 56 patients with ventricular aneurysm following myocardial infarction were enrolled. All patients suffered different levels of angina pectoris symptoms evaluated by Holter (the frequencies of ventricular arrhythmias more than 3 000 per day). They were divided into two groups according to random ballot and preoperative communication with patients' family members: a bipolar radiofrequency ablation group (n=28, 20 males, 8 females, mean age of 61.21±1.28 years) receiving off-pump coronary artery bypass grafting (OPCABG), ventricular aneurysm surgery combined with bipolar radiofrequency ablation, and a non-bipolar radiofrequency ablation group (n=28, 22 males, 6 females, mean age of 57.46±1.30 years) receiving OPCABG and single ventricular aneurysm surgery. The grade of cardiac function and ventricular arrhythmia was compared between the two groups during pre-operation, discharge and   follow-up. Results    All patients were discharged successfully. There was no in-hospital death in both two groups. One patient in the non-radiofrequency group had cerebral infarction. All patients were re-checked with Holter before discharge and the frequency of ventricular arrhythmias significantly decreased compared to that of pre-operation in both groups, and was more significant in bipolar radiofrequency ablation group (1 197.00±248.20 times/24 h vs. 1 961.00±232.90 times/24 h, P<0.05). There was significant difference in duration of mechanical ventilation and ICU stay between the two groups (P<0.05). The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) significantly improved (P<0.05) after operation in both groups. Conclusion    The clinical efficacy of bipolar radiofrequency ablation in the treatment of ventricular aneurysm with ventricular arrhythmia guided by CARTO mapping is safe and effective, but its long-term outcomes still need further follow-up.

Perivenous application of cyanoacrylate tissue sealants reduces intimal and medial thickening of the vein graft and inflammatory responses in a rabbit model of carotid artery bypass grafting.

OBJECTIVES: Effective therapies to prevent vein graft failure after coronary artery bypass grafting (CABG) are still lacking. α-Cyanoacrylate (α-CA, 99% n-octyl-α-cyanoacrylate + n-butyl-α-cyanoacrylate) has been increasingly used as a tissue sealant for wound closure because of its bacteriostatic, biodegradable and haemostatic properties. As a strong tissue adhesive, α-CA might prevent an arterial circulation-induced mechanical stretch on vein graft to attenuate intimal hyperplasia. Here, we investigated the effects of perivenous application of α-CA on the vein graft in a rabbit model of carotid artery bypass grafting. METHODS: Healthy New Zealand white rabbits were randomized into no graft, graft or graft + α-CA group (n = 10 per group). Rabbit carotid artery was bypassed with the jugular vein. α-CA sealants were sprayed on the entire jugular graft including both anastomotic sites after completion of anastomoses. Blood flow parameters and histological characteristics of the vein grafts including vessel wall thickness, number of medial elastic lamina and proliferation index were evaluated 4 weeks after the surgery. The mRNA or protein levels of proinflammatory factors, chemokine (C-C motif) ligand-2 (CCL-2) and tumour necrosis factor-α (TNF-α) were measured 4 weeks after the operation by quantitative reverse transcription polymerase chain reaction or enzyme-linked immunosorbent assay. RESULTS: Compared with the untreated vein grafts at Week 4 after the operation, the α-CA spray significantly improved graft flow (39.4 ± 1.5 vs 27.8 ± 2.9 ml/min, P < 0.01), attenuated intimal and medial thickening (116.3 ± 1.0 vs 159.7 ± 0.9 µm, P < 0.01), reduced anti-proliferating cell nuclear antigen proliferation index of the vein grafts (15.0 ± 0.4 vs 23.6 ± 0.4%, P < 0.01), decreased the mRNA levels of plasminogen activator inhibitor-1 and CCL-2, and reduced the serum levels of TNF-α (92.9 ± 1.7 vs 102.7 ± 1.8 pg/ml, P < 0.01). CONCLUSION: Perivenous application of α-CA sealants exerts short-term beneficial effects on the vein graft and reduces inflammatory responses in a rabbit model of carotid artery bypass grafting. Long-term effects of α-CA on vein graft remodelling and the clinical significance of α-CA in CABG remain to be determined in future studies.

Distal end side-to-side anastomoses of sequential vein graft to small target coronary arteries improve intraoperative graft flow.

BACKGROUND: End-to-side anastomoses to connect the distal end of the great saphenous vein (GSV) to small target coronary arteries are commonly performed in sequential coronary artery bypass grafting (CABG). However, the oversize diameter ratio between the GSV and small target vessels at end-to-side anastomoses might induce adverse hemodynamic condition. The purpose of this study was to describe a distal end side-to-side anastomosis technique and retrospectively compare the effect of distal end side-to-side versus end-to-side anastomosis on graft flow characteristics. METHODS: We performed side-to-side anastomoses to connect the distal end of the GSV to small target vessels on 30 patients undergoing off-pump sequential CABG in our hospital between October 2012 and July 2013. Among the 30 patients, end-to-side anastomoses at the distal end of the GSV were initially performed on 14 patients; however, due to poor graft flow, those anastomoses were revised into side-to-side anastomoses. We retrospectively compared the intraoperative graft flow characteristics of the end-to-side versus side-to-side anastomoses in the 14 patients. The patient outcomes were also evaluated. RESULTS: We found that the side-to-side anastomosis reconstruction improved intraoperative flow and reduced pulsatility index in all the 14 patients significantly. The 16 patients who had the distal end side-to-side anastomoses performed directly also exhibited satisfactory intraoperative graft flow. Three-month postoperative outcomes for all the patients were satisfactory. CONCLUSIONS: Side-to-side anastomosis at the distal end of sequential vein grafts might be a promising strategy to connect small target coronary arteries to the GSV.