Off-pump Coronary Artery Bypass Grafting Procedures Research Articles

Preoperative red cell distribution width and its relation with in-hospital morbidities including atrial fibrillation after coronary artery bypass

Background and Aims: Atrial fibrillation (AF) and other adverse events are significant concerns following coronary artery bypass grafting (CABG). In recent years, Red Cell Distribution Width (RDW) has been identified as a potential biomarker for predicting these adverse outcomes. This study aims to assess early in-hospital adverse events in patients undergoing isolated off-pump CABG (OPCAB) and to analyze the relationship between these events and preoperative RDW levels. Methods: This study prospectively included 150 patients who underwent elective isolated OPCAB procedures. Patients were categorized into an “event group” (those experiencing adverse events) and a “no-event group” (those who did not). Additionally, they were stratified according to preoperative RDW levels into three groups: Group A (RDW ≤14%), Group B (RDW 14-16%), and Group C (RDW ≥16%). A receiver operating characteristic (ROC) curve, followed by both univariate and multivariate regression analyses were utilized to evaluate the predictive value of RDW for in-hospital morbidity. Results: The in-hospital mortality rate was 2.7%, and AF occurred in 20.7% of the patient population. The ROC analysis for early adverse events yielded an Area Under the Curve (AUC) of 0.681 with a p-value <0.001, indicating moderate predictive capability; the sensitivity was 73% and specificity was 64% for RDW ≥14.05%. Multivariate regression analysis demonstrated that RDW independently predicts in-hospital morbidity after OPCAB, with an odds ratio of 0.713 (95% CI 0.566-0.899, p=0.004). Conclusion: Elevated preoperative RDW levels serve as a simple and cost-effective independent predictor of early adverse events following isolated OPCAB.

Predominant Use of Bilateral Internal Mammary Arteries in Off-Pump Coronary Artery Bypass Surgery

Bilateral internal mammary artery (BIMA) in coronary artery bypass grafting (CABG) has been shown to provide long-term clinical benefits over single internal mammary artery (SIMA) grafting. Nevertheless, the perceived technical complexity of the procedure and concerns about potential early postoperative complications, particularly sternal wound infections have led to a utilization rate of BIMA grafting of less than 5% in the United States. We systematically compared early (30-day) post-operative outcomes between the BIMA and SIMA cohorts in patients with similar baseline characteristics. A retrospective single center study was conducted on matched patients, using stabilized inverse probability treatment weighting to mitigate bias between the two study cohorts. From 546 off-pump CABG patients initially identified, we examined 328 BIMA and 213 SIMA grafts from the matched samples. Despite utilizing 60.4% BIMA grafts, we observed similar rates of 30-day overall and cardiac mortality between the BIMA and SIMA groups. Rates of 30-day postoperative complications, including superficial and deep sternal wound infections, stroke, sepsis, acute kidney injury, and cardiac arrest, were similar between the two groups. Rates of 30-day overall and cardiac readmission were also similar. Additionally, median length of hospital stays, intensive care unit stay, and ventilation times were similar between the two groups. In conclusion, our data suggest that a BIMA utilization rate of 60.4% in off-pump CABG procedure is achievable without causing any significant increment in early post-operative complications, including deep sternal wound infection.

Autologous cell salvage in off-pump coronary artery bypass surgery reduces post-operative complications: a retrospective weighted-matching analysis.

Blood transfusion plays a crucial role in coronary artery bypass grafting (CABG). The choice between autologouscell saver (CS) and allogenic blood transfusion (ABT) has been a continuous debate in the medical community, especially within cardiac surgery. This study aimed to assess the outcomes of off-pump CABG (OPCAB) surgery in patients receiving blood solely via cell salvage compared to those receiving ABT or a combination of ABT and CS perioperatively. A total of 414 patients who underwent isolated OPCAB surgery at our cardiovascular clinic were analyzed. Among them, 250 patients (60.4%) received blood via CS alone, while 164 patients (39.6%) received either ABT or a mix of ABT and CS. Stabilized inverse probability treatment weighted (IPTW) matching technique ensured balance in baseline covariates. We found no significant differences in 30-day mortality rates between the CS and ABT groups. The CS group displayed significantly lower rates of overall complications, encompassing stroke, acute kidney injury, atrial fibrillation, and pulmonary complications. Rates of sepsis, readmission, gastrointestinal complications, heparin-induced thrombosis, and deep venous thrombosis were comparable between the two groups. However, in contrast to the ABT group,the CS group exhibited significantly shorter median lengths of hospital stay (LOHS), ICU stay, andventilation time, along with higher rates of discharge to homerather than acute care facilities. Our data suggest that autologous blood transfusion via CS results in fewer perioperative complications and faster recovery following OPCAB procedures as compared to ABT.

Stable Hemodynamics within "No-Touch" Saphenous Vein Graft.

Purpose: To investigate the hemodynamics characteristics of the “no-touch” saphenous vein graft (SVG) conduits by nicardipine intraluminal administration in vivo experiment.Methods: A total of 59 consecutive patients were enrolled and underwent a sequential SVG to three non-left anterior descending (LAD) targets with the average runoff ≤2 mm, 30 with “no-touch” harvest technique (group A) and 29 with conventional preparation (group B). The patients were subject to nicardipine intraluminal injection during off-pump coronary artery bypass grafting (CABG) procedure. The intraoperative flow was measured with the ultrasonic transit time flow meter (TTFM), and the graft patency testified by multi-detector computed tomography (MDCT) angiography, respectively.Results: The baseline blood flow was higher in group A than that in group B (p <0.05). However, the increases in blood flow of SVG conduits in group A were lower than those in group B with 19.7 ± 5.9 vs. 35.4 ± 9.2 mL/min, 14.8 ± 5.6 vs. 23.1 ± 6.8 mL/min, 6.6 ± 2.1 vs. 11.2 ± 4.3 mL/min before the first, second, and third anastomose after nicardipine intraluminal administration, respectively (all p <0.01).Conclusions: No-touch SVGs were associated with higher baseline blood flow and less rises after nicardipine intraluminal administration during off-pump CABG procedure compared with conventional preparation. The no-touch SVGs seemed to be less spastic and well-tolerated on flow dilatation.

Factors associated with early mortality in haemodialysis patients undergoing coronary artery bypass surgery.

SummaryIntroduction:Coronary artery bypass grafting (CABG) results in higher morbidity and mortality rates in end-stage renal disease (ESRD) patient populations than in patients with normal renal function. This study aimed to identify the early results of CABG performed on ESRD patients, and the factors that affected the mortality rates of those patients.Methods:A retrospective evaluation of our hospital database revealed 84 haemodialysis-receiving patients who underwent CABG during the years 2006 to 2012. Mortality was observed in 21 patients (group 1), and this group was compared with the remaining patients (group 2) for peri-operative parameters such as age, EuroSCORE, functional capacity, myocardial infarction, use of inotropes and completeness of revascularisation.Results:The study included 60 male (71.4%) and 24 female patients (28.6%); the participants’ mean age was 59.50 ± 9.93 years. The pre-operative additive EuroSCORE was 7.96 ± 2.88 (range: 2–18). Pre-operative functional capacity was impaired in 35.7% of the patients [New York Heart Association (NYHA) classes III–IV]. Mean age and preoperative EuroSCORE values of group 1 were significantly higher than those of group 2. Impaired functional capacity (NHYA classes III–IV) was also associated with mortality (OR: 3.333; 95% CI: 1.199–9.268).Fifty-four patients (64.3%) underwent on-pump CABG procedures, and 30 (35.7%) underwent off-pump CABG procedures. The study found no statistically significant difference in mortality rates between these two techniques. Mortality occurred in 12 patients (22.2%) in the on-pump group and in nine (30%) in the off-pump group. Complete revascularisation was performed on 46 patients (85.2%) in the on-pump group and seven (23.3%) in the off-pump group (p < 0.001).ConclusionAdvanced age, impaired NYHA functional capacity and pre-operative hypertension were determinative for early-term surgical mortality. An on-pump surgical technique is recommended to ensure completeness of revascularisation.

Clinicopathological comparisons of open vein harvesting and endoscopic vein harvesting in coronary artery bypass grafting patients in Mashhad.

IntroductionHarvesting of the greater saphenous vein is almost an inevitable part of coronary artery bypass grafting (CABG) operations, and it is done by two main techniques, i.e., conventional or open vein harvesting (OVH) and the minimally-invasive endoscopic vein harvesting (EVH). This study aimed to compare these two techniques in off-pump CABG procedures with respect to clinical and pathological outcomes.MethodsThis cohort study was conducted on CABG candidates during a one-year period from October 2013 through September 2014 in the Department of Cardiac Surgery at Mashhad University of Medical Sciences. Eighty-seven patients voluntarily underwent EVH, and another 86 patients matched for age, gender, and other cardiovascular risk factors were selected for OVH. They were followed up for six weeks, and the main outcome measures were infections of the wound, pain, duration of hospital stay, and the costs of hospitalization. Paired sample t-test, independent t-test, or their non-parametric equivalents and the chi-squared test were used by SPSS version 17.0 for data analysis.ResultsThe mean duration of time for vein harvesting was shorter in the EVH group (p < 0.001), and the pain score was lower (p = 0.04). No infections occurred at the site of the wound. The length of hospital stay was not significantly different for the two groups (OVH versus EVH: 8.5 ± 3.3 versus 8.4 ± 3.2 days; p-value: 0.08). Hospitalization costs were significantly higher in the EVH group (OVH versus EVH: 5.8 ± 4.7 versus 7.3 ± 2.0 million Tomman; p-value: 0.008), yet no difference was diagnosed with respect to endothelial damage in the vein grafts harvested by the EVH and OVH techniques.ConclusionEVH is considered as a minimally invasive and safe vein harvesting technique in our Center, and it can reduce the harvesting time and post-operative pain. In addition, its efficiency was similar to that of OVH.

Our Initial Results of Off-pump Coronary Artery Bypass Grafting

Background. On-pump coronary artery bypass grafting (CABG) remains a procedure of choice in patients with ischemic heart disease despite nearly two decades of utilization of off-pump techniques. Nearly all aspects of off-pump CABG operations are still debatable, including indications and contraindications to this procedure. We report here our initial experience with routine application of off-pump CABG in patients with ischemic heart disease. Methods. Results of 96 off-pump CABG procedures performed from May 2015 to date are analyzed. Preoperative demographic and clinical data, intraoperative data and results of postoperative course are analyzed. Our results are compared with the results of other authors and mortality rates are compared to predicted by risk-stratification system “EuroScore” values. Results. The mean number of distal anastomoses was 3.01 +/- 0.07 per patient. In 75 (78.1%) patients we constructed 3 or more grafts, in 22 cases (23%) - we used complex types of surgical technique (sequential, “Y-graft” or “T-graft”). 28 (29.2%) patients required inotropic support in ICU for initial recovery with an average duration of 3.14 +/- 0.74 hours. In 3 (3.1%) patients in the postoperative period were episodes of sustained atrial fibrillation. In 1 (1.04%) patient course of OPCABG procedure was complicated with emergent conversion to on-pump CABG. Mortality was 1.04% (1 patient). Conclusions. A modern OPCABG approach offers low mortality, excellent clinical outcomes, and does not come at the price of less complete revascularization.

Off-pump or minimized on-pump coronary surgery - initial experience with Circulating Endothelial Cells (CEC) as a supersensitive marker of tissue damage

BackgroundOff-pump-coronary-artery-bypass-grafting (OPCAB) and minimized-extracorporeal-circulation (Mini-HLM) have been proposed to avoid harmful effects of cardiopulmonary-bypass (CPB). Controversies exist whether OPCAB is still superior in perioperative outcome. Circulating endothelial cells (CEC) are sensitive markers of endothelial damage and are significantly elevated in conventional-CPB-procedures as compared to Mini-HLM-revascularisation. Therefore, CEC might be of specific value in evaluating effectiveness of Mini-HLM and OPCAB as currently applied less-invasive coronary procedures.Methods76 coronary patients were randomly assigned either to OPCAB (n = 34) or to Mini-HLM (ROCsafe™, Terumo Inc., n = 42) procedures. Perioperative data, clinical and serological outcome and measurements of CEC-release and parameters of endothelial function (v.Willebrand-Factor, soluble-thrombomodulin) perioperatively (pre-operative-baseline, post-Mini-HLM/release of OPCAB-stabilizer, 6 h, 12 h, 24 h and 5 days postoperatively) were obtained and compared by ANOVA models including repeated-measures-analysis.ResultsMean graft-number was 3.06 ± 0.72 in Mini-HLM-patients and 1.89 ± 0.74 in OPCAB-patients (p < 0.001). However, ventilation-, ICU- and total-hospital duration were comparable between groups as well as chest-tube-drainage, transfusion requirements, hemodynamics and catecholaminergic support (p > 0.05). CEC-release did not differ between groups (p = 0.274) and was generally within normal limits, Troponin-T levels where not significanty different (p = 0.108). No myocardial infarctions, strokes or deaths occurred, neuron specific enolase (NSE) did not show any differences between groups (p = 0.194).ConclusionConceptional advantages of minimized CPB systems (ROCsafe™) result in morbidity and mortality comparable with OPCAB procedures. Mini-HLM therefore minimizes CPB-related systemic and organ injury as demonstrated by low CEC-values which indicates intact endothelial integrity. Furthermore, Mini-HLM combines OPCAB-benefits with low morbidity in high-risk patients while facilitating more complete revascularization in complex patients.

Effects of on-pump and off-pump coronary artery bypass grafting on left ventricular relaxation and compliance: a comprehensive perioperative echocardiography study

The short-term effect of coronary artery bypass grafting (CABG) on diastolic function is only moderately investigated. Furthermore, it remains unknown whether avoidance of cardioplegic arrest by an off-pump CABG procedure has advantages over on-pump procedure regarding diastolic relaxation and compliance. We investigated whether components of diastolic function would be improved the day after CABG depending on the type of the surgical procedure. Spontaneously breathing on-pump (n = 20) and off-pump CABG (n = 12) patients underwent a comprehensive transthoracic echocardiography examination the day before and the day after elective CABG, including transmitral and pulmonary vein flow parameters, colour M-mode flow propagation velocity (Vp) and tissue Doppler assessment of the average mitral annulus diastolic velocity (Em). Isovolumic relaxation and E-wave deceleration time were corrected for heart rate (IVRTcHR and DTcHR). Left ventricular (LV) relaxation time (τ) and LV operating stiffness (LVOS) were calculated. Overall and independent from operation type and preload, CABG decreased IVRTcHR (107 ± 20 vs. 93 ± 15 ms) (P < 0.01) and τ (54 ± 10 vs. 45 ± 10 ms) (P < 0.01), increased Vp (49 ± 22 vs. 75 ± 37 cm/s) (P < 0.01), and increased Em (6.6 ± 2.0 vs. 7.3 ± 1.3 cm/s, P = 0.06), indicating improved relaxation. LVOS increased (0.13 ± 0.06 vs. 0.22 ± 0.05 mmHg/mL) (P < 0.01), compatible with an impaired compliance. A similar improvement in relaxation and impairment in compliance were observed in both groups. Myocardial relaxation improved the day after CABG irrespective of the use of cardiopulmonary bypass with cardioplegic arrest. Impairment in compliance could not be prevented by the avoidance of cardioplegia.

Synchronous Carotid Endarterectomy and Off-pump Coronary Bypass: An Updated, Systematic Review of Early Outcomes

Objectives: To update our previous systematic review of outcomes following synchronous carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (OFF-CABG). Design: A systematic review of operative risks reported in published studies of synchronous CEA plus OFF-CABG procedures. Results: We identified 12 eligible studies, including data on 324 synchronous CEA plus OFF-CABG procedures. Operative mortality was 1.5% (95% confidence interval (CI): 0.3–2.8), the risk of death or ipsilateral stroke was 1.6% (0.4–2.8%), risk of death or any stroke was 2.2% (95% CI: 0.7–3.7) and the risk of death, stroke or myocardial infarction was 3.6% (95% CI: 1.6–5.5). Conclusions: Limited published data on 324 patients suggest that early outcomes after synchronous CEA plus OFFCABG are better than those following staged or synchronous CEA plus CABG where the cardiac procedure was performed on-pump. This may, however, be attributed to publication bias, case selection or the fact that the aorta was not manipulated or cannulated, rather than CEA being primarily responsible for the lower stroke risk. Colleagues with unpublished experience of CEA plus OFF-CABG are encouraged to submit their data to further inform the debate.

Off-Pump Coronary Artery Bypass Graft Surgery: A Training Course for Novices and its Learning Curve

The learning curve for off-pump coronary artery bypass grafting (OPCABG) surgery still requires further discussion. Training programs aimed at the conversion of conventional coronary artery bypass grafting (CABG) to OPCABG have mainly been geared towards those persons who already have much experience in conventional CABG. The goals of this study were to retrospectively analyze the training process of two trainees who had no previous coronary surgery experience and to discuss the efficiency and feasibility of the training. Two cardiac surgeons were enrolled in this study; they had different surgical backgrounds but neither had ever previously performed coronary surgery. They were trained to become independent surgeons capable of performing OPCABG procedures by a supervising surgeon who had performed more than 2 000 OPCABG surgeries. Clinical data were collected from each trainee subject's first 100 cases of OPCABG surgery and grouped according to the following scheme: Group A (1) (Doctor A's first 50 cases), Group A (2) (Doctor A's second 50 cases), Group B (1) (Doctor B's first 50 cases) and Group B (2) (Doctor B's second 50 cases). A consecutive series of 50 cases of OPCABG surgery performed by the supervising surgeon served as the control group (Group C). Cumulative sum failure analysis for each subject was used to complete the learning curve study. The training time was 28 months for Doctor A and 24 months for Doctor B; the difference in training time was presumably due to their different surgical backgrounds. Among the cases in Group A (1), Group A (2) and Group B (1), there were fewer distal anastamoses, fewer sequential grafts, and less marginal branch grafting in the left circumflex artery than in the Group C cases. Operating times and ICU stay were longer in Group A (1) than in Group C. There were no group differences with regard to total mortality or the incidence of complications. CUSUM analysis showed that the curves of the two trainees had a small steep elevation during the first 30 cases, and proceeded smoothly thereafter, never passing the 80 % alert lines. The appropriate qualifications for OPCABG trainees and the optimal OPCABG training program have not yet been resolved. In this study, the observed learning curves of cardiac surgeons who had no prior coronary surgery experience during their training to perform the OPCABG procedure by a sophisticated OPCABG surgeon indicated that the training program employed was feasible and its outcomes were reasonable.

Synchronous Carotid Endarterectomy and Off-pump Coronary Bypass: An Updated, Systematic Review of Early Outcomes

To update our previous systematic review of outcomes following synchronous carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (OFF-CABG). A systematic review of operative risks reported in published studies of synchronous CEA plus OFF-CABG procedures. We identified 12 eligible studies, including data on 324 synchronous CEA plus OFF-CABG procedures. Operative mortality was 1.5% (95% confidence interval (CI): 0.3-2.8), the risk of death or ipsilateral stroke was 1.6% (0.4-2.8%), risk of death or any stroke was 2.2% (95% CI: 0.7-3.7) and the risk of death, stroke or myocardial infarction was 3.6% (95% CI: 1.6-5.5). Limited published data on 324 patients suggest that early outcomes after synchronous CEA plus OFFCABG are better than those following staged or synchronous CEA plus CABG where the cardiac procedure was performed on-pump. This may, however, be attributed to publication bias, case selection or the fact that the aorta was not manipulated or cannulated, rather than CEA being primarily responsible for the lower stroke risk. Colleagues with unpublished experience of CEA plus OFF-CABG are encouraged to submit their data to further inform the debate.

A Coronary Active Perfusion System for Off‐pump Coronary Artery Bypass Grafting in an Experimental Porcine Model: The Relationship Between Flow Rate and Myocardial Function

We developed a coronary active perfusion system (synchronized arterial flow ensuring system [SAFE-System]) to prevent myocardial ischemia during distal anastomosis in off-pump coronary artery bypass grafting (CABG). The purpose of this study was to identify the relationship between the flow rate of the SAFE-System and myocardial function. Studies were performed on pigs, which were divided into five groups: external shunt perfusion group (group A, n = 6); 0.1 mL/beat flow rate for the SAFE-System group (group B, n = 6); 0.2 mL/beat flow rate group (group C, n = 6); 0.3 mL/beat flow rate group (group D, n = 6); and 0.4 mL/beat flow rate group (group E, n = 6). Regional myocardial blood flow and left ventricular function were monitored for 30 min. The regional myocardial blood flow in group A was severely decreased (P < 0.001), and was significantly lower than in the other groups (P < 0.001). The slope of the end-systolic pressure-volume relationship, and the slope of the preload recruitable stroke work relationship in groups A, D, and E were lower than in groups B and C. As compared with the use of a passive external shunt, a coronary active perfusion system provides adequate myocardial blood flow and hemodynamics. It was possible to maintain left ventricular function when using 0.1 or 0.2 mL/beat flow rate. The use of a coronary active perfusion system appears to make the off-pump CABG procedure safer and may increase the application of off-pump bypass grafting.

Routine intracoronary shunting in multivessel off-pump coronary artery bypass: a retrospective review of in-hospital outcomes in 550 consecutive cases.

Since 1999 our institution has adopted offpump coronary artery bypass grafting (OPCABG) for treating the majority of our patients. In the year 2001, 96% of our isolated coronary bypass procedures were performed on the beating heart. Routine use of intracoronary shunts in OPCABG has been a controversial topic. We use routine intracoronary shunting in all cases to maintain distal perfusion and to help achieve hemostasis. We reviewed the first 550 OPCABG procedures performed at our institution (July 1998-December 2001) by 2 surgeons currently performing >95% of all coronary bypasses off-pump. All cases were completed with routine intracoronary shunting using Flo-Coil (Guidant, Santa Clara, CA, USA) or Flo-Thru (Bio-Vascular, St Paul, MN, USA) shunts. The mean number of grafts was 3.7. (range, 1-8). In-hospital outcomes in this series of patients were compared to outcomes in 485 patients operated on by the same 2 surgeons using traditional cardiopulmonary bypass (CPB) and aortic cross-clamping prior to adopting routine OPCABG. Statistical significance was calculated using Pearson chisquare analysis and reported for P values of <.05. The rates of occurrence of postoperative cardiovascular accident, atrial fibrillation, prolonged ventilator time, renal failure, and blood product use and the length of postoperative stay were significantly less in the off-pump group (P <.05). Predicted risk of mortality, observed mortality, and perioperative myocardial infarction rates were not significantly different in the 2 groups (P <.05). The conversion rate was 3.1%. We conclude that routine intracoronary shunting in OPCABG is a safe technique that is associated with good myocardial preservation and allows for total revascularization with a low rate of conversion to CPB.

Long-term left internal mammary artery graft patency for coronary artery disease associated with pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is a rare, inherited connective tissue disorder with numerous systemic manifestations that include premature coronary artery disease. Coronary artery bypass grafting (CABG) is known to be beneficial in patients with PXE-related coronary artery disease. In these patients, however, the suitability of arterial conduits, including the internal mammary artery, has been controversial. We present a patient with PXE-related coronary artery disease who has had long-term patency of a left internal mammary artery (LIMA) graft after an off-pump CABG procedure in which LIMA and bilateral radial artery conduits were used.

Coronary artery bypass grafting in an immune thrombocytopenic purpura patient using off-pump techniques

We performed an off-pump coronary artery bypass grafting (OPCABG) procedure on a 60-year-old woman with idiopathic thrombocytopenic purpura (ITP) whose platelet count was 42 × 10 3 per microliter on admission. She was treated with immunoglobulin G (IgG) (0.5 g · kg −1 · d −1) for 4 days, resulting in a platelet count rise to 187 × 10 3 per microliter. She subsequently underwent an uneventful OPCABG procedure without requiring any blood transfusions. The combination of OPCABG and preoperative IgG therapy appears to be an ideal strategy for ITP patients requiring coronary revascularization.