Warm ischemia provokes inflammation and regional hypercoagulability within the heart during off-pump coronary artery bypass: a possible target for serine protease inhibition

Minimally invasive coronary bypass surgery with bilateral internal thoracic arteries: Early outcomes and angiographic patency

OBJECTIVE

Multivessel minimally invasive coronary artery bypass grafting, performed chiefly with left internal thoracic artery and saphenous vein grafts through a left anterolateral thoracotomy, has recently emerged as an alternative to conventional coronary artery bypass grafting. The present study involves our initial experience with respect to early postoperative and angiographic outcomes after total arterial multivessel off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries.

METHODS

A total of 88 consecutive patients undergoing total arterial off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries without ascending aortic manipulation were included in this study. Bilateral internal thoracic arteries were harvested under direct vision through a left anterolateral thoracotomy and used as Y or in situ grafts. Multivessel grafting was performed off pump. Postoperative graft assessment was performed in 51 patients.

RESULTS

The mean age of patients was 67.1 ± 7.2 years, and 79 patients (89.8%) were male. The mean body mass index and ejection fraction were 26.7 ± 2.7 kg/m² and 57.6% ± 6.6%, respectively, and 40 patients (45.5%) had left main disease. No intraoperative conversions to cardiopulmonary bypass or sternotomy occurred. A total of 209 distal anastomoses (mean 2.4 ± 0.5) were performed, with 57 patients undergoing double, 29 patients undergoing triple, and 2 patients undergoing quadruple coronary artery bypass grafting. There was no in-hospital mortality, and 5 patients underwent reexploration for bleeding. No patient had stroke or chest wound infections. Predischarge coronary angiography revealed an overall graft patency rate of 96.8%.

CONCLUSIONS

Off-pump minimally invasive coronary artery bypass grafting using total arterial revascularization with bilateral internal thoracic arteries is a feasible and safe operation that is associated with excellent short-term outcomes and early graft patency. Future studies should focus on improving the generalizability and reproducibility of this technique.

Off-pump coronary artery bypass surgery with bilateral internal thoracic arteries: the Leipzig experience

Background

Contrasting results of recent randomized controlled trials (RCTs) comparing off-pump and on-pump coronary artery bypass graft (CABG) surgery, as well as the lack of evidence for any survival benefit of bilateral internal thoracic artery (ITA) grafting over single ITA use, has intensified the debate about the role of the off-pump technique and bilateral ITA use in CABG surgery. We therefore investigated our 15-year experience in off-pump CABG with bilateral ITA grafting and evaluated temporal trends in preoperative characteristics and postoperative outcomes.

Methods

Demographic, intra-operative, and outcome data of 1,199 consecutive patients undergoing off-pump CABG with bilateral ITA grafting was prospectively collected in a computerized database. Patients who underwent on-pump cardiac procedures and other extra-cardiac procedures were excluded from this study. Assessment of changes in perioperative characteristics and parameters with time was performed by dividing the whole cohort into three groups (2003-2007, 2008-2012, and 2013-2017) based on the year of surgery.

Results

The overall 30-day mortality was 0.6%, with no differences observed between the three time cohorts (0.6%, 0.7%, 0.5%; P=0.8). The perioperative stroke rate for whole cohort was 0.6% and demonstrated a significant reduction in the last two time cohorts (1%, 0.5%, 0.5%; P<0.0001). The overall incidence of deep sternal wound infections was 0.7%, but was marginally higher in the last time-cohort (0.6%, 0.5%, 0.9%; P=0.7). Overall survival for the entire cohort was 92.9%±1% and 78.9%±4% at 5 and 10 years follow-up, respectively. Older age at surgery and presence of peripheral vascular disease were the only predictors of late mortality.

Conclusions

Off-pump CABG with bilateral skeletonized ITAs is a safe operation and is associated with a low mortality and morbidity, which can be maintained in high volume center unit over a long period of time. The long-term survival of patients undergoing such an operation is excellent.

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

Although the two phenomena are usually studied separately, we summarise a considerable body of literature to the effect that a great many diseases involve (or are accompanied by) both an increased tendency for blood to clot (hypercoagulability) and the resistance of the clots so formed (hypofibrinolysis) to the typical, 'healthy' or physiological lysis. We concentrate here on the terminal stages of fibrin formation from fibrinogen, as catalysed by thrombin. Hypercoagulability goes hand in hand with inflammation, and is strongly influenced by the fibrinogen concentration (and vice versa); this can be mediated via interleukin-6. Poorly liganded iron is a significant feature of inflammatory diseases, and hypofibrinolysis may change as a result of changes in the structure and morphology of the clot, which may be mimicked in vitro, and may be caused in vivo, by the presence of unliganded iron interacting with fibrin(ogen) during clot formation. Many of these phenomena are probably caused by electrostatic changes in the iron-fibrinogen system, though hydroxyl radical (OH˙) formation can also contribute under both acute and (more especially) chronic conditions. Many substances are known to affect the nature of fibrin polymerised from fibrinogen, such that this might be seen as a kind of bellwether for human or plasma health. Overall, our analysis demonstrates the commonalities underpinning a variety of pathologies as seen in both hypercoagulability and hypofibrinolysis, and offers opportunities for both diagnostics and therapies.

The effects of tacrolimus on the activity and expression of tissue factor in the rat ovary with ischemia-reperfusion induced injury

In the present study, the effects of tacrolimus on the activity and expression of tissue factor (TF) were investigated in the ovarian ischemia-reperfusion induced injury in rats. Twenty-eight female rats (8-12 weeks, 300-350 g) were divided into four groups: control, ischemia-reperfusion (IR), tacrolimus treated before ischemia (TBI), and tacrolimus treated before reperfusion (TBR) groups (n=7/per group). TF activity was measured using Quick's method, whereas TF expression was examined immunohistochemically. TF activity was significantly higher in all treated groups compared with the control group. Strong ovarian TF expression was demonstrated in the IR and TBR groups. Moreover, tacrolimus decreased TF activity in the TBI group compared with the IR group. The decreased activity of TF in the ovarian IR model may prevent IR-related inflammation during transplant procedure.

Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era?

Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.

Effects of ulinastatin on coagulation in high-risk patients undergoing off-pump coronary artery bypass graft surgery

BACKGROUND

Both systemic inflammatory reaction and regional myocardial ischemia/reperfusion injury may elicit hypercoagulability after off-pump coronary artery bypass grafting (OPCAB). We investigated the influence of ulinastatin, which suppresses the activity of polymorphonuclear leukocyte elastase and production of pro-inflammatory cytokines, on coagulation in patients with elevated high-sensitivity C-reactive protein (hsCRP) undergoing OPCAB.

METHODS

Fifty patients whose preoperative hsCRP > 3.0 mg/L were randomly allocated into the ulinastatin (600,000 U) or control group. Serum concentrations of thrombin-antithrombin complex (TAT) and prothrombin fragment 1+2 (F1+2) were measured preoperatively, immediately after surgery, and at 24 h after surgery, respectively. Secondary endpoints included platelet factor (PF)-4, amount of blood loss, and transfusion requirement.

RESULTS

All baseline values of TAT, F1+2, and PF-4 were higher than the normal range in both groups. F1+2 was elevated in both groups at immediate, and at 24 h after surgery as compared to baseline value, without any significant intergroup differences. Remaining coagulation parameters, transfusion requirement and blood loss during operation and postoperative 24 h were not different between the two groups.

CONCLUSIONS

Intraoperative administration of ulinastatin did not convey beneficial influence in terms of coagulation and blood loss in high-risk patients with elevated hsCRP undergoing multivessel OPCAB, who already exhibited hypercoagulability before surgery.

Effect of tranexamic acid on transfusion requirement in dual antiplatelet-treated anemic patients undergoing off-pump coronary artery bypass graft surgery

BACKGROUND

Anemia is not rare in patients presenting for coronary artery bypass graft surgery (CABG) and as these patients are frequently on dual antiplatelet therapy (DAPT), the coexisting conditions could potentially increase the risk of bleeding and transfusion. The aim of this study was to evaluate the effect of tranexamic acid (TA) on blood loss and transfusion in preoperatively anemic patients who continued DAPT until within 5 days of off-pump CABG (OPCAB).

METHODS AND RESULTS

Seventy-six anemic patients were randomized into 2 groups: TA group receiving TA (1g bolus followed by infusion at 200mg/h) and a Control group receiving the same volume of saline. The amount of blood loss and transfusion requirement during, and at 4 and 24h after the operation were assessed. Patients' characteristics and operative data were similar between the groups. During the perioperative period, which combined the intraoperative and postoperative 24h data, the TA group received significantly smaller amounts of packed red blood cells and fresh frozen plasma. Total amount of perioperative blood loss was similar between the groups, although the blood loss during the postoperative 4h was significantly less in the TA group.

CONCLUSIONS

TA infusion could reduce the amount of transfusion during the perioperative period in patients with preoperative anemia who continue DAPT until within 5 days of OPCAB.

Ischemia/reperfusion injury in kidney transplantation: mechanisms and prevention

Ischemia has been an inevitable event accompanying kidney transplantation. Ischemic changes start with brain death, which is associated with severe hemodynamic disturbances: increasing intracranial pressure results in bradycardia and decreased cardiac output; the Cushing reflex causes tachycardia and increased blood pressure; and after a short period of stabilization, systemic vascular resistance declines with hypotension leading to cardiac arrest. Free radical-mediated injury releases proinflammatory cytokines and activates innate immunity. It has been suggested that all of these changes-the early innate response and the ischemic tissue damage-play roles in the development of adaptive responses, which in turn may lead to an acute font of kidney rejection. Hypothermic kidney storage of various durations before transplantation add to ischemic tissue damage. The final stage of ischemic injury occurs during reperfusion. Reperfusion injury, the effector phase of ischemic injury, develops hours or days after the initial insult. Repair and regeneration processes occur together with cellular apoptosis, autophagy, and necrosis; the fate of the organ depends on whether cell death or regeneration prevails. The whole process has been described as the ischemia-reperfusion (I-R) injury. It has a profound influence on not only the early but also the late function of a transplanted kidney. Prevention of I-R injury should be started before organ recovery by donor pretreatment. The organ shortage has become one of the most important factors limiting extension of deceased donor kidney transplantation worldwide. It has caused increasing use of suboptimal deceased donors (high risk, extended criteria [ECD], marginal donors) and uncontrolled non-heart-beating (NHBD) donors. Kidneys from such donors are exposed to much greater ischemic damage before recovery and show reduced chances for proper early as well as long-term function. Storage of kidneys, especially those recovered from ECD (or NHBD) donors, should use machine perfusion.