Adventitial Collagen Cross-Linking by Glutaraldehyde Reinforcing Human Saphenous Vein - Implication for Coronary Artery Bypass Grafting

ABSTRACT Introduction: A weak venous wall is one of the major reasons contributing to vein graft failure after coronary artery bypass grafting (CABG). We investigated whether adventitial collagen cross-linking by glutaraldehyde reinforces venous wall, preserving the endothelium of veins during high-pressure distention. Methods: Human saphenous veins (SVs) were collected from 40 patients undergoing CABG, and adventitia cross-linking was performed with 0.3% glutaraldehyde for five minutes. The cross-linked SVs were accessed by biodegradation assay, immunofluorescent staining, and tensile test. Native SVs and cross-linked SVs from another 20 patients received the 200 mmHg pressure distention for two minutes. Pressure-induced injury of SVs were accessed by immunohistochemistry and electron microscopy. Results: Time to digestion was 97±13 minutes for native SVs and 720±0 minutes for cross-linked SVs (P<0.05). After adventitial cross-linking, the collagen I fibres of the vein remarkably presented with compact and nonporous arrangement. In the high-stretch region (stretch ratio 1.4-1.8), the Young's elastic modulus of stress-stretch ratio curve in cross-linked SVs was larger than that in native SVs (13.88 vs. 5.83, P<0.05). The cross-linked SVs had a lower extent of endothelial denudation without fibre fracture during high-pressure distension than native SVs. Comparing with the non-cross-linked SVs, the percentage of endothelial nitric oxide synthase staining length on the endothelium of cross-linked SVs was significantly preserved after high-pressure distension (85.2% vs. 64.7%, P<0.05). Conclusion: Adventitial collagen cross-linking by glutaraldehyde reinforced venous wall by increasing stiffness and decreasing extensibility of SVs and mitigated the endothelial damage under high-pressure distension.

Left ventricular aneurysm repair: off-pump linear plication versus on-pump patch plasty

Abstract Objective: The study aimed to compare the clinical outcomes of simplified linear plication and classic patch plasty in patients with left ventricular aneurysm (LVA). Methods: We retrospectively reviewed 282 patients undergoing LVA repair between 2006 and 2016. After propensity score matching, 45 pairs of patients receiving LVA surgery were divided into either a patch group (on-pump endoventricular patch plasty) or a plication group (off-pump linear plication). Then, their early surgical outcomes and long-term survival were compared in two matched groups. Results: The heart function improvement at discharge was similar in the two matched groups, while patients in the patch group more commonly suffered from low cardiac output syndrome (P=0.042) with higher proportion of intra-aortic balloon pumping assistance (P=0.034) than patients in the plication group. Compared with patients in the patch group, the patients in the plication group had shorter recovery times, regarding to mechanical ventilation, intensive care unit stay, and hospital stay (P<0.001, P<0.001, and P=0.001, respectively). No significant difference was found in the long-term survival (P=0.62). Conclusions: Off-pump linear plication presented acceptable results in terms of early outcomes and long-term survival. For high-risk patients, the simplified LVA repair technique may be an option.

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.