An Appraisal of Different Cardiac Risk Reduction Strategies in Vascular Surgery Patients

OBJECTIVES: to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery. DESIGN: review of the literature. MATERIALS AND METHODS: a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures. RESULTS: coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients. CONCLUSIONS: coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.     

Periprocedural P2Y12 inhibitors improve perioperative outcomes after carotid stenting by primarily decreasing strokes

ObjectiveThe continuation of antiplatelet agents in the periprocedural period around carotid stenting (CAS) procedures is felt to be mandatory to minimize the risk of periprocedural stroke. However, the optimal antiplatelet regimen is unclear, with some advocating dual antiplatelet therapy, and others supporting the use of P2Y₁₂ inhibitors alone. The objective of this study was to evaluate the periprocedural effect of P2Y₁₂ inhibitors for CAS.MethodsThe Vascular Quality Initiative was used from years 2007 to 2020. All transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TF-CAS) procedures were included. Patients were stratified based on perioperative use of P2Y₁₂ inhibitors as well as symptomatic status. Primary end points were perioperative neurological events (strokes and transient ischemic attacks). Secondary end points were mortality and myocardial infarction.ResultsA total of 31,036 CAS procedures were included for analysis, with 49.8% TCAR and 50.2% TF-CAS cases; 63.8% of patients were male and 82.3% of patients were on a P2Y₁₂ inhibitor. P2Y₁₂ inhibitor use was more common in males, asymptomatic patients, those older than 70 years, and concurrent statin use. P2Y₁₂ inhibitors were more likely to be used in TCAR cases than in TF-CAS cases (87.3% vs 76.8%; P < .001). The rate of periprocedural neurological events in the whole cohort was 2.6%. Patients on P2Y₁₂ inhibitors were significantly less likely to experience a periprocedural neurological event (2.3% vs 3.9%; P < .001) and mortality (0.6% vs 2.1%; P < .001) than those who were not on a P2Y₁₂ inhibitor. There was no effect on the rates of myocardial infarction. On multivariate analysis, both symptomatic and asymptomatic patients on P2Y₁₂ inhibitors were significantly less likely to develop perioperative neurological events. Additionally, the use of P2Y₁₂ inhibitors demonstrated an independent significant effect in reducing of the rate of perioperative stroke (odds ratio, 0.29; 95% confidence interval, 0.25-0.33). Finally, additional analysis of the types of P2Y₁₂ inhibitors used revealed that all seemed to be equally effective in decreasing the periprocedural neurological event rate.ConclusionsThe use of perioperative P2Y₁₂ inhibitors seems to markedly decrease the perioperative neurological event rate with TCAR and TF-CAS in both symptomatic and asymptomatic patients and should be strongly considered. Patients with contraindications to P2Y₁₂ inhibitors may not be appropriate candidates for any CAS procedure. Additionally, alternative types of P2Y₁₂ inhibitors seem to be equally effective as clopidogrel. Finally, an analysis of the Vascular Quality Initiative demonstrates that, even for TCAR cases, only 87.3% of patients seem to be on P2Y₁₂ inhibitors in the periprocedural period, leaving room for significant improvement.     

Revascularization of the Posterior Circulation

The primary objective of revascularization procedures in the posterior circulation is the prevention of vertebrobasilar ischemic stroke. Specific anatomical and neurophysiologic characteristics such as posterior communicating artery size affect the susceptibility to ischemia. Current indications for revascularization include symptomatic vertebrobasilar ischemia refractory to medical therapy and ischemia caused by parent vessel occlusion as treatment for complex aneurysms. Treatment options include endovascular angioplasty and stenting, surgical endarterectomy, arterial reimplantation, extracranial-to-intracranial anastomosis, and indirect bypasses. Pretreatment studies including cerebral blood flow measurements with assessment of hemodynamic reserve can affect treatment decisions. Careful blood pressure regulation, neurophysiologic monitoring, and neuroprotective measures such as mild brain hypothermia can help minimize the risks of intervention. Microscope, microinstruments and intraoperative Doppler are routinely used. The superficial temporal artery, occipital artery, and external carotid artery can be used to augment blood flow to the superior cerebellar artery, posterior cerebral artery, posterior inferior cerebellar artery, or anterior inferior cerebellar artery. Interposition venous or arterial grafts can be used to increase length. Several published series report improvement or relief of symptoms in 60 to 100% of patients with a reduction of risk of future stroke and low complication rates.     

冠心病病人骨髓间充质干细胞的生物学特征评价

目的　确立胸骨骨髓间充质干细胞分离和培养的方法 ,评价其生物学特征。方法　骨髓取自行冠状动脉旁路移植术的冠心病病人胸骨切口 ,用Percoll液分离骨髓MSCs,体外培养扩增 ,观察细胞生长特性 ,流式细胞仪检测骨髓MSCs表型特征、细胞周期。结果　贴壁的骨髓MSCs多数呈梭形。骨髓MSCs能连续传 15代以上 ,但是第 5代以后或老年病人的细胞增殖速度减慢。骨髓MSCs的表型特征为CD2 9、CD4 4阳性 ,CD34、CD4 5阴性。多数骨髓MSCs在细胞周期的G0 /G1期。结论　冠心病病人手术时从胸骨切口取骨髓并分离培养骨髓MSCs的方法可行 ,骨髓MSCs具有较好的增殖更新潜能 ,是细胞心肌成形术中理想的细胞来源。     

Histochemical study of transmyocardial laser channels in dogs

目的　了解激光心肌血运重建术时激光对心肌的损伤。方法　在狗心肌上用CO2 激光打孔。术后即刻、两周时于打孔处取材 ,用硝基蓝四唑法作琥珀酸脱氢酶、乳酸脱氢酶组织化学染色。结果　术后即刻 ,孔道及其周围心肌分为五个区。中央为孔道即组织汽化区 ,向外依次为碳化区、酶消失区、酶减少区、酶浓缩区。两周后孔道区被肉芽组织取代 ,周围心肌细胞酶活性正常。结论　激光心肌血运重建术术后即刻 ,孔道周围心肌细胞酶活性由内向外依次呈消失、减少、浓缩改变。术后两周可逆性损伤的心肌细胞酶活性恢复。     

一站式杂交技术与冠状动脉旁路移植术治疗冠心病多支病变的对比研究

目的 评价一站式杂交技术在治疗冠状动脉粥样硬化性心脏病（以下简称冠心病）多支病变中的手术安全性及疗效。方法 选取该院行一站式冠状动脉杂交手术患者23 例和胸骨正中切口非体外循环下冠状动脉搭桥术患者23 例,其中杂交组在经胸骨下段小切口以左乳内动脉至左前降支搭桥,术毕行冠状动脉支架介入手术,治疗“罪犯”血管,另外23 例患者行常规胸骨正中非体外循环下冠状动脉搭桥术,比较两组患者的手术效果及并发症发生情况。结果 两组围手术期均无患者死亡。杂交组手术时间较常规组短（P <0.05）。杂交组输注红细胞和血浆量较常规组少（P <0.05）;杂交组术中出血量、24 h 引流量及血肌钙蛋白量较常规组少（P <0.05）;杂交组重症加强护理病房停留时间、机械通气时间及引流管保留时间较常规组短（P <0.05）。结论 一站式杂交技术治疗冠心病多支病变较常规冠状动脉搭桥术具有安全性高、创伤小、并发症少及恢复快等优点,值得临床推广应用。     

再管化微创治疗动脉硬化闭塞/狭窄性疾病

目的:探讨再管化微创治疗动脉硬化闭塞/狭窄性疾病的疗效。方法:对47例经皮穿刺血管腔内球囊扩张及支架移植再管化微创治疗动脉硬化闭塞/狭窄性疾病患者的临床资料进行回顾性分析。结果:动脉血管再管化即时成功46例。34例随访24个月,血管腔内球囊扩张及球囊扩张加支架移植再管化24个月通畅率分别为78.57%及85%。结论:经皮穿刺血管腔内球囊扩张再管化是微创治疗动脉硬化闭塞/狭窄性疾病的有效方法,血管腔内支架移植有助于提高24个月血管通畅率。     

血管内皮生长因子干预烟熏大鼠肺气肿的实验研究

目的:探讨血管内皮生长因子(VEGF)对烟熏大鼠肺气肿病变的修复作用。方法:Wistar大鼠24只,随机分为VEGF组、对照组和健康对照组。VEGF组、对照组用烟熏气管内滴入猪胰弹性蛋白酶制作肺气肿模型,健康对照组气管内滴入生理盐水作为对照,3个月后模型成功。VEGF组大鼠气管内滴入VEGF,对照组和健康对照组滴入生理盐水,每周1次,共3次。4周后测大鼠体重,肺泡形态学变化。结果:VEGF组与对照组相比平均肺泡数明显增加(P<0.05)、平均肺泡间隔和平均肺泡面积减小(P<0.05)。结论:VEGF在一定程度上可以修复肺气肿病变。     

颈部大动脉出血急救及血管修复重建(附6例11次报告)

目的 总结6例11次颈部大动脉破裂出血的急救及血管修复重建经验.方法 2002年12月至2008年12月我科共完成6例11次颈部大动脉破裂出血抢救,男性4例,女性2例,年龄12～67岁,中位年龄48岁.原发病为甲状腺癌术后双侧声带麻痹1例,甲状腺癌复发1例,甲状腺癌术后左侧声带麻痹1例,下咽癌复发1例,头颈部外伤1例,颈动脉体瘤1例.4例为二次手术,术后均给予放疗,放疗剂量60～80Gy.11例次大出血中无名动脉破裂1例2次,颈总动脉4例8次,颈内动脉1例1次.术中大出血4例4次,血管修复术后再次破裂大出血4例6次,外伤1例1次.结果 充分暴露破裂血管后行血管修补5例次,人工血管移植吻合1例次,颈内动脉修剪后直接吻合1例次,大隐静脉重建2例次,颈总动脉结扎2例次.3例1次修复成功,1例2次修复成功,2例因放疗及感染原因血管修补重建后反复缝线脱落遂给予结扎.血管重建后采用胸大肌肌瓣3例、胸锁乳突肌2例保护颈部大动脉.全部病例均抢救成功,无围手术期死亡,1例因颈动脉结扎导致术后偏瘫.所有病例均完整随访,1例出院1周内再次大出血死亡,1例因肿瘤复发1年内死亡,1例存活3年以上至今,3例存活5年以上至今.结论 一旦发生颈部大动脉出血,先以手指压迫,切忌以血管钳盲目钳夹;迅速备血、补足血容量,积极抗休克治疗是抢救成功的前提;血管修复重建能有效防止术后出现神经系统并发症,需采用个体化血管修复方案;如无法修复重建可考虑颈总动脉结扎.