Current trends and technique in OPCAB surgery

Monocyte-to-Lymphocyte Ratio as a Predictor of Worse Long-Term Survival after Off-Pump Surgical Revascularization-Initial Report

Background and objective: Coronary artery disease is one of the leading causes of deaths nowadays and the trends in diagnosis and revascularization are still in plateau despite well-known factors. Simple whole blood count parameters may be used to measure inflammatory reactions that are involved in processes of atherosclerosis progression. The aim of our study was to analyse the association between simply available hematologic indices and long-term mortality following off-pump coronary artery bypass grafting (OPCAB). Material and Methods: The study group comprised 129 consecutive patients (16 females and 113 males, mean age 66 ± 6 years) who underwent surgical revascularization with off-pump technique between January 2014 and September 2019. The mean follow-up was 4.7 +/−1.9 years. A receiver operating characteristics curve was applied to estimate demographical and perioperative parameters including MLR for mortality. Results: Cox regression analysis revealed chronic pulmonary obstructive disease (HR = 2.86, 95%CI 1.05–7.78), MLR (HR = 3.81, 95%CI 1.45–10.06) and right coronary artery blood flow (HR = 1.06, 95%CI 1.00–1.10) as significant factors predicting increased mortality risk. In the presented model, the MLR > 1.44 on 1st postoperative day was a significant predictor of late mortality after the OPCAB procedure (HR = 3.82, 95%CI 1.45–10.06). Conclusions: Pronounced inflammatory reaction after off-pump surgery measured by MLR > 1.44 can be regarded as a worse long-term prognostic factor.

Functional Modular Network Identifies the Key Genes of Preoperative Inhalation Anesthesia and Intravenous Anesthesia in Off-Pump Coronary Artery Bypass Grafting

Off-pump coronary artery bypass grafting (OPCABG) is an effective strategy for revascularization. Preoperative anesthesia appears critical due to surgical instability and the risk of organ damage. This study, based on a functional module network, analysed the effects of preoperative inhalation anesthesia and intravenous anesthesia on OPCABG and performed a pivot analysis of its potential drug regulators. We obtained microarray data of sevoflurane anesthesia and propofol anesthesia from the GEO database and analysed the difference between the two groups of data, resulting in 5701 and 3210 differential genes to construct the expression matrix. WGCNA analysis showed that sevoflurane anesthesia clustered into 7 functional disorder modules, including PDCD6IP, WDR3, and other core genes; propofol anesthesia clustered to form two functional disorder modules, including KCNB2 and LHX2, two core genes Enrichment analysis of the functions and pathways of interest suggests that both anesthesia-related module genes tend to function as pathways associated with ion and transmembrane transport. The underlying mechanism may be that targeted regulation of transmembrane-associated biological processes and ion pathways in the core genes of each module affect the surgical process. Pivot analysis of potential drug regulators revealed 229 potential drugs for sevoflurane anesthesia surgery, among which zinc regulates three functional disorder modules via AHSG, F12, etc., and 67 potential drugs for propofol anesthesia surgery, among which are propofol, methadone, and buprenorphine, regulate two functional disorder modules through four genes, CYP2C8, OPRM1, CYP2C18, and CYP2C19. This study provides guidance on clinical use or treatment by comparing the effects of two anesthesias on surgery and its potential drugs.

Comprehensive Study of Different Expressed Genes and Their Functional Modules in Anesthesia for Off-Pump Coronary Artery Bypass Grafting

Purpose

The effect of preoperative anesthesia on coronary artery bypass grafting without extracorporeal circulation is not apparent. We want to investigate the effects and molecular mechanisms of two anesthesia methods on the treatment of coronary artery bypass grafting (OPCABG) under extracorporeal circulation. Patients and Methods. The data of inhaled anesthesia and intravenous anesthesia before coronary artery bypass grafting were downloaded from the GEO database, and the differences were analyzed with the control group. The combination of multiple analytical methods can decipher the mechanism of anesthesia on surgery, including protein interaction network analysis, enrichment analysis, and regulatory subprediction.

Results

This study obtained 6699 differential genes under two kinds of anesthesia before OPCABG. By constructing a protein interaction network of differentially expressed genes, we obtained 14 functional module networks. By predicting regulators of functional module genes, we revealed a series of ncRNAs (miR-129-5p, miR-340-5p, and miR-410-3p) and transcription factors (VHL and YBX1).

Conclusion

Based on functional module network analysis, we identified the effects of preoperative inhalation anesthesia and intravenous anesthesia on OPCABG, which provides a valuable theoretical reference for subsequent clinical studies.

Aortic Arch Atheroma: Stroke Reduction in Cardiac Surgical Patients

Cardiac surgery is increasingly performed on elderly patients with extensive coronary artery abnormalities who have impaired left ventricular function, decreased physiologic reserve, and multiple comorbid conditions. Considerable numbers of these patients develop perioperative neurologic complications ranging from subtle cognitive dysfunction to more evident postoperative confusion, delirium, and, less commonly, clinically apparent stroke. Magnetic resonance imaging studies have elucidated that a considerable number of patients have new ischemic brain infarcts, particularly after conventional coronary artery bypass graft surgery. Mechanisms of cerebral injury during and after cardiac surgery are discussed. Intraoperative transesophageal echocardiography and epiaortic scanning for detection of atheromatous disease of the proximal thoracic aorta is paramount in identifying patients at high risk from neurologic injury. It is important to recognize that our efforts to minimize neurologic injury should not be limited to the intraoperative period. Particular efforts should be directed to temperature management, glycemia control, and pharmacologic neuroprotection extending into the postoperative period. Preoperative magnetic resonance angiography may be of value for screening patients with significant atheroma of the proximal thoracic aorta. It is likely that for patients with no significant atheromatous disease, conventional coronary artery revascularization is the most effective long-term strategy, whereas patients with atheromatous thoracic aorta may be better managed with beating heart surgery, hybrid techniques, or medical therapy alone. Patient stratification based on the aortic atheromatic burden should be addressed in future trials designed to tailor treatment strategies to improve long-term outcomes of coronary heart disease and reduce the risks of perioperative neurologic injury.

Off-pump coronary artery surgery with the Coronéo Cor-Vasc stabilizing device: clinical experience of 141 patients

OBJECTIVES

Numerous devices have been successfully introduced in off-pump coronary artery bypass graft (OPCABG) surgery, most of them being disposable tools based on suction stabilization. Coronéo Cor-Vasc is a reusable system combining suction positioning with compression stabilization. The purpose of this study was to analyze our experience in OPCABG with the Cor-Vasc system.

METHODS

Between March 2001 and May 2008, 141 patients (age = 71.1 +/- 7.5 years) underwent OPCABG surgery using the Cor-Vasc system, representing 6.3% of the case volume of isolated coronary artery bypass graft surgery in the same period. Eighty-eight patients (62.4%) underwent surgery on an urgent basis. In 95 patients (67.4%), the OPCABG option was selected after finding a diseased ascending aorta at intraoperative epiaortic ultrasound.

RESULTS

Among 334 anastomoses (mean = 2.4 +/- 1 per patient), 242 (95 patients) were fashioned with bilateral and 54 (46 patients) with single internal thoracic artery, respectively. In 89.4 and 73% of patients, a complete and a total arterial myocardial revascularization was achieved, respectively. There were two strokes (1.4%) and two myocardial infarctions (1.4%). Two patients died in the hospital (1.4%). Median ICU and in-hospital length of stay were 31.2 h and 10 days, respectively.

CONCLUSION

In our experience, the use of the Cor-Vasc system, including the device-learning curve, was associated with low mortality and morbidity indexes in an aged population with a high risk of stroke. The system appeared to be sufficiently versatile and potentially cost-effective when compared with disposable devices.

Influence of on-pump versus off-pump techniques and completeness of revascularization on long-term survival after coronary artery bypass

BACKGROUND

Off-pump coronary artery bypass graft surgery (OPCABG) may be associated with reduced morbidity and in-hospital mortality. In this study, we report the influence of surgery type, number of grafts, and the Index of Completeness of Revascularization (ICOR), namely, the number of grafts/number diseased vessel systems, on long-term survival.

METHODS

From 1997 to 2006, 12,812 consecutive patients underwent isolated CABG at a single academic center. Ten-year survival data were obtained by cross-referencing patients with the national Social Security Death Index. A propensity score analysis of 46 preoperative characteristics balanced risk factors between surgical groups. A proportional hazards regression analysis modeled the hazard of death as a function of surgery type (on versus off), distal group (1 to 3 versus 4 to 7 vessels), ICOR, and propensity score.

RESULTS

Proportional hazards regression analysis showed no significant influence of surgery type or number of grafts on long-term survival within the four groups: OPCABG 1 to 3 grafts (n = 3,946; ICOR 1.11), OPCABG 4 to 7 grafts (n = 1,721; ICOR 1.56), on-pump CABG 1 to 3 grafts (n = 3,380; ICOR 1.21), and on-pump CABG 4 to 7 grafts (n = 3,765; ICOR 1.64). Irrespective of technique of revascularization, there was a survival advantage for patients with higher ICOR.

CONCLUSIONS

Long-term survival was similar for patients receiving 1 to 3 or 4 to 7 grafts by either on-pump or off-pump techniques. However, higher ICOR was associated with improved long- term survival within all groups.

Significant reduction in blood loss in patients undergoing minimal extracorporeal circulation

Several recent studies have shown differences in blood loss and allogeneic transfusion requirements between on-pump and off-pump coronary artery bypass grafting (CABG). Recently a new concept, the mini-extracorporeal circulation, was introduced to minimize the side effects of extracorporeal circulation. Therefore, there are no data comparing the three techniques with special emphasis to blood loss and transfusion requirements. Two hundred and eighty-five patients undergoing first-time coronary artery bypass grafting were retrospectively matched for number of grafts, age and sex. Ninety-five patients underwent surgery with the off-pump CABG (OPCAB) technique, 97 patients using conventional CABG with cold cardioplegia (CCABG) and 93 patients with the mini-extracorporeal circuit with warm blood cardioplegia (MCABG). Blood loss for the CCABG group with a mean loss of 819 +/- 557 mL and the OPCAB group with a mean loss of 870 +/- 768 mL was significant different compared to the MCABG group with a mean loss of 679 +/- 290 mL. The use of units red blood cell units was significantly higher for CCABG group and OPCAB group compared to the MCABG group. On the day of operation the use of platelet concentrate was significantly higher for the CCABG group compared to MCABG group. As a consequence of improvements of several components of the mini heart lung machine, significantly less blood products are needed in MCABG patients. The expected reduced need for transfusion when the pump was completely avoided could not be confirmed in this single retrospective cohort study.

Evaluation of ischemic injury of the cardiac tissue by using the principal component analysis of an epicardial electrogram

Monitoring and control of the heart tissue viability is of crucial importance during heart surgery operations. In most cases the heart tissue suffers from an ischemic injury that causes a decrease in the velocity of electrical excitation propagation in it and influences the shape of the excitation wave front that spreads over the injured area. It is reflected in a more complex shape of the registered epicardial electrogram as compared to normal. A method for quantitative evaluation of the complexity of the shape of the epicardial electrogram based on the principal component analysis is here proposed for evaluation of the ischemic injury of the cardiac tissue. A minimal, yet sufficient, number of the principal components (the optimal basis functions) for truncated expansion of the epicardial electrogram signals could be used as an estimate of signal complexity. The method for determination of such a minimal, yet sufficient, number of principal components were developed by using epicardial electrograms registered during in situ experiments on dogs in which local ischemia was evoked by ligation of a coronary vessel.

Heart tissue viability monitoring in vivo by using combined fluorescence, thermography and electrical activity measurements

A prototype system for in vivo monitoring of the heart tissue viability by using combined measurements of fluorescence, thermography and electrical activity has been elaborated for cardiac surgery. The fluorescence imaging of nicotinamide adenine dinucleotide NAD(P)H in the blue light range (lambda=467 nm) by using UV light (lambda=347 nm) excitation was used to detect metabolic disturbances. The method of the principal component analysis was used for the processing of the fluorescence image sequences. Far infrared (lambda=7.5-13 microm) imaging was used to evaluate temperature dynamics of the tissue surface during circulation disturbances. Evaluation of the epicardial electrogram shape by using continuous wavelet transform was used to detect and evaluate ischemia-caused disturbances of the electrical activity of the tissue. The combination of temperature, fluorescence and electrical activity estimates obtained from synchronically registered parameters during the experiments on model systems and experimental animals yielded qualitatively new results for the evaluation of cardiac tissue viability and enabled to achieve a versatile evaluation of the heart tissue viability.

Hemodynamic management of patients in the first 24 hours after cardiac surgery

OBJECTIVE

To describe the physiologic alterations, evaluation, and hemodynamic management of patients in the first 24 hrs after cardiac surgery.

DESIGN

A brief review of preoperative and intraoperative events, postoperative physiology, and a discussion of the evaluation and hemodynamic management of cardiac surgery patients postoperatively based on a review of the literature, known physiology, and clinical experience.

RESULTS

After cardiac surgery, patients undergo alterations in cardiac performance related to co-morbid conditions, preoperative myocardial insults and interventions, the surgical procedure, and intraoperative management. Predictable responses evolve rapidly in the first 24 hrs after surgery. Monitoring, diagnostic regimens, and therapeutic regimens exist to address the patterns of response and occasional complications.

CONCLUSION

By understanding preoperative and intraoperative events and their evolution in the intensive care unit, clinicians can effectively manage patients who experience cardiac surgery.

Serum S-100 β Protein During Coronary Artery Bypass Graft Surgery With or Without Cardiopulmonary Bypass

BACKGROUND

Brain damage is a serious complication of cardiac anesthesia. The purpose of this study was to detect brain damage at different surgical stages during coronary artery bypass graft with or without cardiopulmonary bypass.

METHODS

We conducted a prospective, longitudinal study to evaluate serum S-100 beta protein, an early marker of brain injury, in patients electively undergoing off-pump (n = 30) or traditional coronary artery bypass graft (n = 60). Blood was sampled immediately before anesthesia, before and after cardiopulmonary bypass, and on the day after surgery.

RESULTS

Serum S-100 beta protein was lowest immediately before induction of anesthesia and significantly increased before and after cardiopulmonary bypass, then declined by the first postoperative day in both groups. Peak values were highest in the traditional group directly after coronary artery bypass graft. On the day after surgery, S-100 beta protein levels were similar between groups, but were higher than baseline within each group. Significant increase in serum S-100 beta protein was also observed even before cardiopulmonary bypass in cardiopulmonary bypass patients, or before manipulation of the heart and aorta in off-pump patients. These reflect the possibility that brain damage may occur before major manipulation (cardiopulmonary bypass or manipulating heart and aorta). Moreover, S-100 beta levels did not return to normal on the day after the operation.

CONCLUSIONS

This prospective study has shown that serum S-100 beta protein was not only higher than baseline both after cardiopulmonary bypass and on the day after surgery in both groups of patients but it was also significantly increased before cardiopulmonary bypass or manipulation of the heart or aorta. These findings may have implications for anesthesiologic care during the total course of cardiac surgery.

Outcome of elderly patients undergoing open-heart surgery in a developing country

To evaluate and compare the outcome of open-heart surgery in elderly patients with a concurrent group of younger patients in a developing country, data of all adult patients who underwent open-heart surgery during the period of 3 years from January 1999 to December 2001 were collected prospectively. Demographic data such as age and gender, other data such as preoperative diagnoses, comorbid illnesses, type of surgery, time of cardio-pulmonary bypass, length of stay and hospital outcome were recorded. The characteristics of patients above the age of 65 years were compared with a concurrent cohort of patients aged less than 65 years. One hundred and forty-five adult patients underwent open-heart surgeries in 3 years, and the overall mortality rate was 4.8%. The much common surgeries were coronary artery bypass grafting, valve repair/replacement surgery and surgery for adult congenital heart diseases. Forty-five (31%) patients were above the age of 65 years. The mortality rate was 2.2% for patients who were aged 65 years and above, in comparison with that of the concurrent cohort of younger patients (6%). This was probably because of more number of surgeries for congenital heart diseases in the latter group. However, even with other surgeries such as coronary artery bypass grafting, the elderly group of patients did equally well as the younger group. Elderly patients tolerate cardiac surgery well, and age should not be an exclusive criterion to decide against open-heart surgery.

The incidence and risk of acute renal failure after cardiac surgery

OBJECTIVE

To evaluate outcome and risk factors of acute renal failure in a surgical population with or without preoperative renal dysfunction.

DESIGN

Observational study.

SETTING

Intensive care unit at a University Hospital.

PARTICIPANTS

Five thousand sixty-eight consecutive adult patients who underwent cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Perioperative variables measured were age, sex, basic pathology, preoperative renal impairment defined as creatinine >1.4 mg/dL, ventricular dysfunction, preoperative neurologic event, chronic obstructive pulmonary disease, diabetes, type of surgery, use of intra-aortic balloon pump (IABP), cardiopulmonary bypass (CPB) duration, redo or emergency surgery, hemorrhage, blood transfusion, surgical revisions, and postoperative complications.

MEASUREMENTS AND MAIN RESULTS

Acute renal failure (100% creatinine increase) developed in 171 (3.4%) patients, whereas 94 patients (1.9% of the population) had renal replacement therapy. Hospital mortality was 40.9% in patients with acute renal failure and increased to 63.8% when renal replacement therapy was requested. Sex, age, emergency surgery, low ejection fraction, IABP device, redo, diabetes, mitral valve surgery, CPB duration, and preoperative renal disease were independently associated with acute renal failure at a multivariate analysis.

CONCLUSION

This study confirms that acute renal failure is one of the major complications of cardiac surgery, identifies the risk factors, and suggests that optimizing cardiac output and reducing CPB time could improve the outcome of patients at high risk of acute renal failure.