Safety and efficacy of off-pump coronary artery bypass grafting

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

Optimum heparin dose in off-pump coronary artery bypass grafting: A systematic review and meta-analysis

INTRODUCTION

Off-pump coronary artery bypass grafting (OPCABG) was introduced many years ago aiming to reduce the known complications of conventional on-pump coronary surgeries. Heparin is required during the procedures, but the available protocols have diverse dosage regimens. The primary objective of this systematic review is to examine the effect of different heparin doses on the outcomes of OPCABG.

EVIDENCE ACQUISITION

MEDLINE and EMBASE were searched. Four reviewers identified eligible clinical trials. Two reviewers extracted data and independently assessed the risk of bias using Cochrane tool. The primary outcome was the activated clotting time (ACT) at three minutes. The secondary outcomes were proportion of patients requiring blood products and the length of hospital stay. An aggregate data approach was used.

EVIDENCE SYNTHESIS

Three single-center randomized studies recruiting 256 patients were included. The studies compared low-dose (1.5-2 mg/kg) and high-dose (3 mg/kg) heparin boluses. The overall mean difference for ACT after three minutes between low- and high-dose heparin is - 126.16 (95% CI: - 142.19, - 110.14). The proportion of patients requiring blood products after surgery [odd ratio 1.27 (95% CI: 0.69, 2.32)] or the overall length of stay [mean difference -0.15 (95% CI: -0.84, 0.53)] did not differ between the heparin doses.

CONCLUSIONS

In OPCABG, high-dose compared with low-dose heparin did not affect the utilization of more blood products or increased the overall length of stay. Unsurprisingly, ACT values were higher in the high-dose heparin group. Larger and adequately powered randomized clinical trials are indicated to resolve the uncertainty.

Use of Impella CP Device in Off-Pump Coronary Artery Bypass Graft Surgery

Off-pump coronary artery bypass grafting (OPCABG) may be performed on patients with high surgical risk who are poor candidates for traditional mechanical circulatory support. Hemodynamic support with micro-axial mechanical circulatory devices has been performed with limited but promising results.We report a case of a 66-year-old male with multiple comorbidities and low cardiac output undergoing OPCABG. Impella CP device was deployed for "in-pump" support during surgical coronary revascularization resulting in intraoperative stability and uncomplicated post-operative recovery.Previous reports have described the use of the Impella Recover LP 5.0 device for use during OPCABG. We describe the successful and safe perioperative use of the Impella CP device. Despite lower flow rates, adequate support was achieved and the transfemoral cannulation and smaller outer diameter than the Impella 5.0 device may decrease the risk of complications and expedite recovery. Further research will be necessary to determine the optimal perioperative hemodynamic support strategy to offer hemodynamically unstable, high, and prohibitive risk patients.

Massive air embolism during off-pump CABG: A case report

Off-pump coronary artery bypass grafting (OPCAB), although devoid of the morbidity associated with cardiopulmonary bypass (CPB), has its own technical difficulties. Achieving optimum tissue stabilization on a beating heart along with hemodynamic fragility due to extreme positioning also complicates the anesthetic management. In addition, it is difficult to obtain a clear surgical field in the presence of arteriotomy. The use of catheter-directed high-flow gas blower (mister blower) helps achieve a clear surgical field to a great extent. However, there have been reported cases of arterial and pulmonary embolism caused by these high-flow gas blowers. The present case reports a case of massive venous air embolism caused by the use of mister blower.

Hemostatic Control of Coronary Arteries with Poloxamer 407 Reverse-Thermal Polymer during Off-Pump Coronary Artery Bypass Surgery in a Pig Model

Objective

To evaluate a new material, poloxamer 407 reversethermal polymer, which may be of value in controlling bleeding during off-pump coronary anastomoses.

Methods

Poloxamer 407 reverse-thermal polymer is a clear, nontoxic compound that is a viscous liquid at room temperature but instantly changes to a firm, water-soluble gel when warmed to body temperature. Six pigs underwent off-pump coronary artery bypass with the left internal mammary artery to the left anterior descending coronary artery. Blood loss from the arteriotomy was measured over a 15-minute period before and after injection of 500 μL intracoronary polymer. After completion of the anastomosis, 10 mL of cold saline was poured along the left anterior descending artery to facilitate dissolution of the polymer. The heart was allowed to beat 2 additional hours with blood flowing through the left internal mammary to left anterior descending graft, after which a completion angiogram was obtained to evaluate graft patency and to look for gross angiographic evidence of coronary branch occlusion or intraluminal filling defects. The animals were then humanely euthanized, and myocardium from the area subtended by the left anterior descending was harvested for histologic evaluation.

Results

All animals successfully underwent the surgical procedure and survived until study termination without any complications. The amount of bleeding from coronary arteriotomy was significantly higher before intracoronary injection of the polymer (5.25 ± 1.65 mL/min versus 0.54 ± 0.53 mL/min, P = 0.0004). Angiography demonstrated that the graft was patent, and there was no evidence of intraluminal foreign bodies. Myocardial samples from the subtended bed showed no evidence of intraarterial polymer or myonecrosis.

Conclusions

Poloxamer 407 reverse-thermal polymer may be a valuable tool in performing coronary anastomoses off-pump. Completion angiograms showed total dissolution of the material with no residual intraarterial polymer visible on tissue samples.

Outcomes after Off-Pump Reoperative Coronary Artery Bypass Grafting

Objective

Application of off-pump techniques to reoperative coronary artery bypass (redo CABG) has been limited by technical difficulty and potential for embolism of atheromatous debris from diseased grafts, resulting in myocardial infarction and rapid hemodynamic deterioration. We compared outcomes after off-pump (OPCAB) and on-pump (ONCAB) in redo CABG.

Methods

A retrospective chart review was performed for patients who underwent redo CABG at a single academic institution between January 1997 and December 2004. Outcomes were compared between groups based on intention to treat. Propensity scores were calculated for each patient using 23 preoperative risk factors. Logistic regression was applied for each end point as a function of group and propensity score.

Results

A total of 771 consecutive patients had redo CABG (639 ONCAB and 132 OPCAB); 22 patients (16.7%) were converted from OPCAB to ONCAB for hemodynamic in stability, severe adhesions, or graft injury; 7 patients (1.1%) were converted from ONCAB to OPCAB for severe aortic calcification. Propensity-matched comparison of outcomes after OPCAB versus ONCAB for redo CABG showed that OPCAB was associated with a reduction in postoperative complications, transfusion, atrial fibrillation, and length of stay. OPCAB patients received fewer grafts with similar use of left internal mammary artery conduit; conversion from OPCAB to ONCAB did not reduce the benefit of OPCAB.

Conclusions

OPCAB can be safely and effectively applied to reoperative CABG in selected cases.

Off-Pump versus Conventional Coronary Artery Bypass Grafting: A Meta-Analysis and Consensus Statement from the 2004 ISMICS Consensus Conference

Background

The purpose of this evidence-based consensus statement is to systematically review and meta-analyze the randomized and nonrandomized evidence comparing off-pump (OPCAB) to conventional coronary artery bypass (CCAB) surgery and to provide consensus on the role of OPCAB in low- and high-risk surgical patients.

Methods and Results

This consensus conference was conducted according to the American College of Cardiology (ACC)/American Heart Association (AHA) standards for development of clinical practice guidelines. The Steering Committee collated all published studies of OPCAB versus CCAB through May 2004 and developed six questions central to controversies surrounding OPCAB surgery in mortality, morbidity, and resource utilization. For mixed-risk patient populations, meta-analysis of 37 randomized clinical trials (3,369 patients, Level A) reported across a total of 53 papers, and two meta-analyses of nonrandomized trials (Level B) comparing OPCAB versus CCAB were identified. For high-risk patient populations, we performed a meta-analysis of 3 randomized and 42 nonrandomized trials (26,349 patients, Level B).

Conclusion

Meta-analysis of Level A and B evidence provided the basis for the following consensus statements in patients undergoing surgical myocardial revascularization: (1) OPCAB should be considered a safe alternative to CCAB with respect to risk of mortality [Class I, Level A]; (2) With appropriate use of modern stabilizers, heart positioning devices, and adequate surgeon experience, similar completeness of revascularization and graft patency can be achieved [Class IIa, Level A]; (3) OPCAB is recommended to reduce perioperative morbidity [Class I, Level A]; (4) OPCAB may be recommended to minimize midterm cognitive dysfunction [Class IIa, Level A]; (5) OPCAB should be considered as an equivalent alternative to CCAB in regard to quality of life [Class I, Level A]; (6) OPCAB is recommended to reduce the duration of ventilation, ICU and hospital stay, and resource utilization [Class I, Level A]; (7) OPCAB should be considered in high-risk patients to reduce perioperative mortality, morbidity, and resource utilization [Class IIa, Level B].

Off-pump versus on-pump complete coronary artery bypass grafting: Comparison of the effects on the renal damage in patients with renal dysfunction

BACKGROUND

We aimed to compare off-pump technique with on-pump technique on renal function in patients with nondialysis-dependent renal dysfunction who underwent coronary artery bypass grafting.

METHODS

The 94 patients with renal dysfunction undergoing isolated coronary artery bypass grafting were retrospectively analyzed. No patient was receiving dialysis. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass and beating heart. Both groups were compared in terms of renal dysfunction parameters and dialysis requirement. The logistic regression models were constructed to identify risk factors associated with dialysis requirement.

RESULTS

Renal dysfunction requiring dialysis developed in 9 patients in the on-pump group. The measures analysis of variance was performed on the data that showed worsening of renal function in the on-pump group compared with the off-pump group. Cardiopulmonary bypass is significant as independent predictor for the development of postoperative dialysis.

CONCLUSION

These results suggest that off-pump coronary revascularization offers a superior renal protection and has a significantly lower risk for renal complications in patients with nondialysis-dependent renal dysfunction when compared with conventional coronary revascularization with cardiopulmonary bypass.

Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

Introduction:

While off pump coronary artery bypass surgery is practiced with an intention to reduce the morbidity associated with cardiopulmonary bypass, the resultant ‘hypercoagulability’ needs to be addressed. Complications such as cavitary thrombus possibly due to the hyper coagulability after off pump coronary artery bypass surgery have been described. Many clinicians use higher doses of heparin - up to 5 mg/kg in order to thwart this fear. Overall, there appears to be no consensus on the dose of heparin in off pump coronary artery bypass surgeries.

Aim of the Study:

The aim of the study was understand the differences in outcome of such as transfusion requirement, myocardial ischemia, and morbidity when two different doses were used for systemic heparinization.

Methods:

Elective patients scheduled for off pump coronary artery bypass surgery were included. Ongoing anti platelet medication was not an exclusion criteria, however, anti platelet medications were ceased about a week prior to surgery when possible. Thoracic epidural anesthesia was administered as an adjunct in patients who qualified for it. By computer generated randomization chart, patients were chosen to receive either 2 or 3 mg/kg of intravenous unfractioned heparin to achieve systemic heparinization with activated clotting time targeted at >240 secs. Intraoperative blood loss, postoperative blood loss, myocardial ischemic episodes, requirement of intraaortic balloon counter pulsation and transfusion requirement were analyzed.

Results:

Sixty two patients participated in the study. There was one conversion to cardiopulmonary bypass. The groups had comparable ACT at baseline (138.8 vs. 146.64 seconds, P = 0.12); 3 mg/kg group had significantly higher values after heparin, as expected. But after reversal with protamine, ACT and need for additional protamine was similar among the groups. Intraoperative (685.56 ± 241.42 ml vs. 675.15 ± 251.86 ml, P = 0.82) and postoperative blood loss (1906.29 ± 611.87 ml vs 1793.65 ± 663.54 ml, p value 0.49) were similar among the groups [Table 4]. The incidence of ECG changes of ischemia, arrhythmias, conversion to CPB, or need for intra-aortic balloon counter pulsation were not different.

Conclusions:

Use of either 2 or 3 mg/kg heparin for systemic heparinization in patients undergoing OPCAB did not affect the outcome.

Methodological approach in adopting off-pump coronary artery bypass surgery in a British cardiothoracic unit: Harefield experience

The theoretical and practical disadvantages of coronary artery bypass graft surgery using cardiopulmonary bypass with cardioplegic arrest are well reported in the literature. Encouraged by our work and others, we adopted a systematic approach to the application of off-pump coronary artery bypass surgery. We aimed to validate the non-selective use of the off-pump technique in all patients and assess the outcome in specific patient groups including: patients with ischaemic left ventricular dysfunction, female and high-risk patients. We investigated specific technical details related to off-pump surgery including: the potential effect of the distortion of the mitral valve on haemodynamic stability intraoperatively and the feasibility of sequential coronary artery bypass grafting using the off-pump technique. We also compared the outcome to the national United Kingdom performance in a risk-stratified manner. An extensive retrospective data review for comparative analysis of outcome was carried out at both local and multi-centre levels. This showed that off-pump surgery was feasible for all patients, and provided a better outcome in patients with ischaemic left ventricular dysfunction, female and high-risk patients. The distortion of the mitral valve contributed to the haemodynamic instability. In conclusion, off-pump surgery is safe and provides better outcome in specific patient groups.

A Meta-Analysis of Miniaturized Versus Conventional Extracorporeal Circulation in Valve Surgery

The effects of miniaturized extracorporeal circulation in patients operated on for heart valve surgery are still inconsistent. We performed a meta-analysis of eight studies involving 1,011 patients to evaluate the comprehensive effects of miniaturized extracorporeal circulation. The results suggested its application significantly reduced the length of stay in the intensive care unit and total hospital stay after heart valve surgery, but no significant effects on reducing postoperative morbidity and mortality were observed. Further studies with long-term follow-up are needed to confirm our results.

Stroke Rate of Off-pump Coronary Artery Bypass; Aortocoronary Bypass Versus in-Situ Bypass

Off-pump coronary artery bypass (OPCAB) using in-situ grafts does not require aortic manip ulation, and it is theoretically free from the risk of stroke. Because of the limited availability of in-situ grafts, aortocoronary bypass has been conducted in addition to in-situ grafting. In this paper, the authors prospectively investigated whether or not on aortocoronary bypass increases the incidence of stroke after off-pump bypass. Perioperative data were collected prospectively from patients who underwent isolated off-pump bypass at their hospital group between March 1997 and February 2002. The patients were divided into 2 groups; group AC (patients with at least 1 aortocoronary bypass, n = 280) and group IS (patients with all in-situ grafts, n = 234). Patients with 3-vessel disease more frequently underwent aortocoronary bypass and patients with a history of stroke, calcified ascending aorta, or renal failure more often underwent in-situ graft. The number of distal anastomoses was greater in group AC (3.5 ± 1.0) than in group IS (2.7 ± 1.1), p < 0.0001. Patient recovery and complication rates were similar, including the occurrence of postoperative stroke: 3.0% (7/234) in group IS vs 0.7% (2/280) in group AC, p=0.051, NS. The graft patency and remote results were not significantly different between the 2 groups. Side clamping of the aorta used in off-pump aortocoronary bypass does not increase the risk of postoperative strokes compared to in-situ bypass. Postoperative stroke after OPCAB may depend on the patient's preoperative comorbidities.

Hybrid coronary revascularization: a systematic review

The hybrid approach to coronary revascularization is an evolving technique that is being used as an alternative to the traditional median sternotomy coronary artery bypass graft surgery. It combines a minimally invasive approach to bypass the left anterior descending coronary artery with a percutaneous approach to revascularize the other coronary arteries. A systematic review of the available literature was conducted to evaluate the benefits, and the short- and long-term outcomes of this procedure.

On-pump beating heart coronary revascularization: Is it valid for emergency revascularization?

BACKGROUND

On-pump beating heart coronary artery bypass grafting (CABG) may be considered as an alternative to the conventional on-pump surgery in patients presenting with acute coronary syndrome requiring emergency revascularization. This study reports our clinical experience and early outcomes with the on-pump beating heart coronary surgery on patients with acute coronary syndrome.

DESIGN AND SETTINGS

A retrospective study conducted from August 2009 to October 2015, in a regional training and research hospital in Turkey.

METHODS

A total of 1432 patients underwent isolated CABG at our institution. A total of 316 of these patients underwent the on-pump beating heart procedure without cardioplegic arrest by the same surgeon.

RESULTS

The time interval from the onset of acute myocardial infarction to CABG was 10 (2.2) hours. The mean number of grafts was 3.0 (0.6). Hospital mortality was 2.9% (9 patients). Twelve patients had low cardiac output syndromes after surgery. Eight of them had renal dysfunction but none of them needed hemodialysis. The mean intensive care unit stay was 3 (2) days and the mean hospital length of stay was 7 (4) days.

CONCLUSION

We think that the on-pump beating heart revascularization technique can be a good choice for emergency CABG of high-risk patients with a multivessel coronary artery disease.

Nonthyroidal illness syndrome in off-pump coronary artery bypass surger

OBJECTIVE

It is well known that coronary artery bypass grafting (CABG) is often the cause of non-thyroidal illness syndrome (NTIS). Non-thyroidal illness syndrome (NTIS) is a state characterized by low levels of tri-iodo-thyronine (T3) and high levels of reverse T3 (rT3), with normal or low levels of thyroxin (T4) and normal, low-normal, or low levels of thyroid-stimulating hormone (TSH). Today, there are two main techniques of CABG: CABG with the use of cardiopulmonary bypass (on-pump coronary artery bypass - ONCAB) and CABG without the use of cardiopulmonary bypass (off-pump coronary artery bypass OPCAB), or 'beating-heart surgery.' The OPCAB technique is considered to be less invasive. We prospectively investigated the influence of these surgical techniques on the occurrence of NTIS.

METHODS

Serum levels of free fractions of thyroid hormones (FT3 and FT4) and TSH were analyzed in 70 consecutive patients subjected to CABG surgery, using the ONCAB technique in 36 patients and OPCAB technique in 34 patients. The measurements of hormone levels were performed prior to surgery and 12 hours and 14 days after surgery.

RESULTS

The basic, the early, and the late postoperative serum levels of FT3 (p=0.458, p=0.632, p=0.869, respectively), FT4 (p=0.664, p=0.301, p=0.417, respectively), and TSH (p=0.249, p=0.058, p=0.324, respectively) were similar in both groups. The levels of FT3 and TSH were significantly lower 12 hours after surgery (p<0.0001, p<0.0001, respectively), and the FT4 levels rose at the same time (p<0.0001). The third measurement showed the return of all investigated parameters back to physiological levels, although they were still not precisely within the initial values.

CONCLUSION

NTIS occurs significantly in patients subjected to CABG. Although the OPCAB technique is considered to be less invasive, its impact on the occurrence of NTIS does not differ significantly from the ONCAB technique.

Off-pump coronary revascularization: A potential benefit for female patients?

Coronary artery disease is one of the leading causes of illness for both men and women. However, women are 3 times more likely to die for coronary artery disease as they are of breast cancer. There are an increasing prevalence of coronary artery disease in women and thus facing the need for surgical revascularization. It has long being accepted that women carry a high risk of coronary surgery than men. Many investigators have suggested that female itself is predictive of poor outcome after on pump coronary surgery. We thought to search the litlature to investigate whether women who undergo off-pump surgery receive any benefits compared with women undergoing on-pump surgery.

Does Off-pump Coronary Artery Bypass Reduce the Prevalence ofAtrial Fibrillation?

INTRODUCTION

To examine whether or not off-pump CABG (Coronary Artery Bypass Reduce) reduces the incidence of AF after cardiac surgery.

METHODS

The study was carried out in 939 consecutive coronary artery disease patients with sinus rhythm from which 383 patients underwent off-pump CABG, and 556 patients were operated through on-pump CABG. All patients were monitored postoperatively during intensive care unit (ICU) stay. Then, the incidence and predictive risk factors of post operative AF (POAF) in two groups were determined and compared with each other.

RESULTS

Overall, the mean age of the patients was 56.0±12.8 years with 234 patients (24.9%) being older than 65 years. POAF developed in 38 patients (9.9%) of the off-pump and in 93 patients (16.7%) of the on-pump CABG. There was significant difference between two groups when considering the incidence of POAF (P=0.002). Among preoperative risk factors, age>65 years had a significant association with the incidence of AF in both groups. This study also showed that most of the POAF cases converted to sinus rhythm after treatment. Moreover, these finding demonstrated that conversion to sinus rhythm is significantly more probable in off-pump group (P=0.006).

CONCLUSION

A reduced prevalence of POAF could be observed in patients with off-pump as compared with on-pump techniques. Furthermore, conversion to sinus rhythm in off-pump group was significantly more probable than on-pump group.

Less invasive coronary artery revascularization with a minimized extracorporeal circulation system: preliminary results of a comparative study with off-pump-procedures

BACKGROUND

Coronary-artery-bypass-grafting (CABG) with conventional extracorporeal circulation (CECC) is associated with adverse effects such as systemic inflammatory response leading to a decrease in systemic vascular resistance and hemodynamic instability. Modern "less invasive" procedures have been established recently which potentially avoid negative side effects of CECC. The aim of this study was to compare perioperative outcome following coronary revascularization using either a minimized extracorporeal circuit (Mini-HLM) or off-pump technique (OPCAB).

METHODS

In this prospective ethics-approved trial, 120 patients referred for CABG were randomly assigned either to off-pump coronary artery bypass (OPCAB) or to a Mini-HLM procedure. Patient demographics, preoperative characteristics and extensive postoperative outcome were analyzed for both groups. Hemodynamic data were measured at seven time points perioperatively.

RESULTS

Operation-time was longer in the Mini-HLM group (178,3 ± 32,9 min) compared to OPCAB (133,2 ± 32,7 min, p < 0,001) with higher graft numbers in Mini-HLM group (3,11 ± 0,7 vs. 1,78 ± 0,7, p < 0.001). There were no significant differences in perioperative hemodynamic criteria, catecholaminergic support, hospital (p = 0,534) and intensive care unit stay (p = 0,880), ventilation time (p = 0,113), blood loss (p = 0,570), transfusion requirements, postoperative atrial fibrillation rate (p = 0,706) and neurocognitive disturbance (p = 0,297). No deaths and no myocardial infarctions were observed.

CONCLUSIONS

Coronary revascularisation with Mini-HLM represents a suitable and "less invasive" procedure which achieves all benefits of OPCAB but may allow for less demanding revascularisation than OPCAB in special patients with complex coronary anatomy and can therefore be used both on a routine basis and in all "conversion" cases of OPCAB.

Risk of renal dysfunction after less invasive multivessel coronary artery bypass grafting

OBJECTIVE

Several centers have established that off-pump, multivessel coronary artery bypass grafting performed via a small thoracotomy (MVST) is feasible. However, this procedure can be challenging when posterolateral coronary targets need to be grafted. We hypothesized that use of cardiopulmonary bypass via peripheral access (MVST-PA) would improve outcomes compared with a completely off-pump approach (OP-MVST).

METHODS

This was a prospective observational study of patients undergoing OP-MVST (n = 46) versus MVST-PA (n = 45) using bilateral internal mammary artery grafts onto the left anterior descending coronary artery and circumflex/right coronary artery distribution. Hemostasis was quantified by measuring platelet function (aggregometry), chest tube output, thrombolysis in myocardial infarction bleeding score (%hematocrit change at 24 hours), and transfusion requirements. The rate of mortality and major morbidity at 30 days was defined according to The Society of Thoracic Surgeons criteria. Estimated glomerular filtration rate (normalized to baseline levels) was determined daily until discharge.

RESULTS

The OP-MVST versus MVST-PA groups had similar risk factors at baseline and risks of composite morbidity/mortality at 30 days. However, renal failure was significantly increased after OP-MVST (10.87 vs 0%, P = 0.05), and MVST-PA affected hemostasis as evidenced by inhibition of platelet function (latency to response on aggregometry, 29.9 vs 17.9 seconds; P = 0.04) and higher transfusion requirement (2.31 vs 0.85 units of red blood cells/patient, P = 0.04; 55.6% vs 34.8% transfused; P = 0.059). However, 24-hour chest tube output was similar (645 vs 750 mL; P = 0.53).

CONCLUSIONS

In comparison with a completely off-pump strategy, use of cardiopulmonary bypass to assist MVST reduced the risk of renal dysfunction with only modest tradeoffs in other morbidities, for example, altered coagulation and higher transfusion requirements. These data justify further study of the effect of MVST-PA on renal complications.

[Results of coronary artery bypass grafting with left ventricular dysfunction (comparison of off-pump versus on-pump)]

BACKGROUND

The aim of this study was to compare the results of myocardial revascularisation with or without cardiopulmonary bypass in patients with impaired left ventricular function.

PATIENTS AND METHODS

Five hundred and sixteen consecutive patients who underwent coronary artery bypass grafting from January 2000 through December 2007 were analyzed retrospectively. One hundred and eight cases had a left ventricular EF (ejection fraction) of 45% or less. Of these patients, 78 underwent conventional coronary artery bypass (CCABG) and 30 underwent off-pump procedure (OCABG). The CCABG group received 300IU/kg of heparin while the OCABG received 100IU/kg. The off-pump coronary surgery was carried out using a tissue stabilizer Octopus II. Different pre-, per- and postoperative variables were evaluated among both groups. Statistical analysis was performed by SPSS 11.5. The variables were compared between these two groups using univariate analysis (Chi(2) test, Fisher's test exact) for qualitative variable and (Student's t test, Mann-Whitney's test) for quantitative variable.

RESULTS

Patients profiles and risk factors were similar among both groups except for age (CCABG: 57.8±9.2 year vs OCABG: 52±9.9 year; P=0.004) and left ventricular EF (CCABG: 37.4±6.3% vs OCABG: 34±7.8%; P=0.02). The number of grafts performed per patient was significantly more among patients who underwent extracorporeal circulation (CCABG: 2.53±0.7 graft/patient vs OCABG: 1.77±0.8 graft/patient; P<0.0001). The hospital mortality was more among CCABG group 9% vs 3.3% in OCABG but the difference was not significant (P=0.3). However, the operative time and the operative room stay were long in CCABG (252±61min vs 175±38min; P<0.0001 - 389±70min vs 298±54min; P<0.0001). The ventilation time was also long in CCABG (32.3±67hour vs 10.4±5.9hour; P=0.15). There was more postoperative myocardial infarction in CCABG (P=0.008), but the EF increased and was better in CCABG.

CONCLUSION

Off-pump coronary artery bypass surgery provides satisfactory operative results for most patients with reduced left ventricular function. Prospective and randomly study will be necessary before concluding.

Pericardium reconstruction with the starfish heart positioner after extended thymectomy with combined left side pericardium resection

We describe the use of the Starfish 2 heart positioning device as an aid to pericardium reconstruction after en bloc resection of mediastinal tumors of the left pericardium by use of median sternotomy with anterolateral thoracotomy. The Starfish device, which is a tool for off-pump coronary artery procedures, allows excellent cardiac positioning and hemodynamic stability during pericardium reconstruction through a median sternotomy with anterolateral thoracotomy.

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm(2) (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm(2) before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system.

Resource utilization in off-pump versus conventional coronary artery bypass grafting in a community hospital: a comparative analysis using propensity scoring

BACKGROUND

At a time when cost containment in health care is under increased scrutiny, coronary artery bypass grafting remains the most widely performed cardiac surgical procedure in the world. This study compares 30-day mortality, morbidity, and resource use for off-pump coronary artery bypass (OPCAB) versus conventional coronary artery bypass (CCAB) revascularization.

METHODS

From January 2000 through December 2008, 1003 patients underwent OPCAB grafting by a single surgeon (S.C.S.). Data were prospectively collected, entered into a Society of Thoracic Surgeons adult cardiac surgery database, and analyzed retrospectively. We used propensity-matching techniques to match this cohort to a group of 1003 patients who underwent CCAB.

RESULTS

The hospital mortality rate was lower for the OPCAB patients than for the CCAB patients: 2.0% (20/1003) versus 2.8% (28/1003). Predictors of hospital mortality for the entire cohort included age (P = .001), cardiogenic shock (P = .001), congestive heart failure (P = .019), history of myocardial infarction (P = .001), and reoperation (P = .007). The overall incidence of morbidity was lower for the OPCAB patients (reoperation for bleeding, P = .011; prolonged ventilation, P = .035; stroke, P = .045; cardiac arrest, P = .004). OPCAB patients experienced significantly reduced procedure times (P = .001), postoperative ventilation times (P = .035), post-operative lengths of stay (P = .035), and blood product use (intraoperative, P = .001; postoperative, P = .001).

CONCLUSION

These outcomes clearly demonstrate that OPCAB is a safe and effective procedure for myocardial revascularization. This retrospective, nonrandomized observational study has shown that the patients who underwent OPCAB had reduced morbidity and mortality, as well as decreased resource use, compared with those who underwent CCAB.

A new application for the heart positioner in operations for mediastinal tumors

We applied a heart positioner during operations to remove large mediastinal tumors. Fixing and lifting the tumor with this device allowed a good view behind the tumor. Separating the tumor from surrounding structures was easy and safe, with no risk of insult. The device caused no damage to the tumor capsule. This could represent a novel method to remove large mediastinal tumors safely and effectively.

Current state of surgical myocardial revascularization

Despite increasing competition from percutaneous interventions and other novel methods of non-surgical coronary revascularization, coronary artery bypass grafting (CABG) remains one of the most definitive and durable treatments for coronary artery disease, especially for those patients with extensive and diffuse disease. In recent years the CABG procedure itself has undergone innovation and evolution. This review article provides a brief historical perspective on the procedure, and examines the current state of modern variations including off-pump, limited-access, and robotic-assisted CABG.

Off-Pump versus On-Pump Coronary Artery Bypass Procedures: Postoperative Renal Complications in an Asian Population

Introduction: Diabetes and habitual smoking cause advanced coronary artery disease (CAD) in Asian patients at a younger age. No definite data exist as to whether off-pump (OPCAB) is better than conventional on-pump coronary artery bypass grafting (CCAB) in terms of postoperative renal complications. Thus, we aimed to compare the renal outcomes of on-pump and off-pump coronary artery bypass grafting (CABG) on our patients, which constituted a predominantly Asian population. Materials and Methods: A cohort of 395 patients following CCAB were compared with 293 patients who underwent OPCAB. Baseline demographics, comorbidities, intraoperative data, intensive care unit stay, number of grafts, New York Heart Association (NYHA) score, American Society of Anesthesiologists (ASA) score, EuroSCORE risk assessment model, and postoperative complications particularly renal, were collected and analysed. Results: The off-pump group consisted of significantly older patients with higher Canadian Cardiovascular Society (CCS) and ASA scores. Additionally, the off-pump group involved a significantly greater number of smokers and chronic obstructive pulmonary disease (COPD) patients. Other demographic parameters were not different between the groups. Postoperative investigations showed a significantly elevated serum creatinine (100.3 ± 42.5 vs 127.6 ± 114.2 μmol/L; off-pump vs on-pump; P = 0.039) and urea levels (5.9 ± 3.1 vs 10.6 ± 15.6 mg/dL; off-pump vs on-pump; P = 0.006) in the on-pump group. Moreover, there was a high tendency towards a higher rate of renal dysfunction associated death in this group. Conclusions: OPCAB is a safe and equally efficient operative method compared to CCAB, and has a significant lower risk for postoperative renal complications as a treatment modality for surgical coronary revascularisation. Key words: Cardiopulmonary bypass, Renal dysfunction

Fewer grafts performed in off-pump bypass surgery: patient selection or incomplete revascularization?

BACKGROUND

Comparisons of off-pump (OPCAB) versus conventional on-pump coronary artery bypass (CCAB) consistently report fewer grafts per patient with OPCAB. Performing fewer grafts than indicated based on angiographic assessment could result in incomplete revascularization. We questioned whether OPCAB influenced surgeons to perform fewer grafts than needed.

METHODS

Preoperative angiographic and surgical data were collected prospectively on 945 patients undergoing coronary artery bypass grafting (370 OPCAB, 575 CCAB) at 8 hospitals between February 1, 2004, and July 31, 2004. The number of grafts needed per patient was determined from the reported number of vessels with angiographic stenoses of 50% or greater, and compared with the number received per patient, stratified by coronary artery bypass grafting technique.

RESULTS

The OPCAB and CCAB groups were demographically similar. The mean number of grafts needed per patient was significantly less in the OPCAB group (2.95 versus 3.48), accounting for fewer grafts received in that group (2.75 versus 3.36). The ratio of grafts (received/needed) was the same in both groups. Patients receiving more than three grafts were more likely to have CCAB (71.2%), whereas those receiving fewer than three grafts were almost as likely to have OPCAB as CCAB (55.5%). The rate of 1-year major adverse events (death, myocardial infarction, repeat revascularization) was the same in OPCAB and CCAB (15.5% versus 14.1%; p = 0.57).

CONCLUSIONS

Completeness of revascularization, determined by comparing the number of grafts performed to the number needed, was equivalent in OPCAB and CCAB patients, and 18-month clinical outcomes were equivalent. Preferential selection of patients needing more bypass grafts to CCAB results in the lower mean number of grafts per patient with OPCAB.

Renal outcome following on- and off-pump coronary artery bypass graft surgery

A prospective study was carried out to compare the outcomes of patients with preexisting non-dialysis-dependent renal dysfunction who underwent coronary artery bypass grafting with or without cardiopulmonary bypass. Elective off-pump coronary artery bypass was performed in 29 patients with renal dysfunction. Their results were compared with those of a similar group of 35 patients who underwent the conventional on-pump coronary artery grafting. There was a significant deterioration in creatinine clearance in the on-pump group on days 1, 2, and 4 after surgery, while creatinine clearance in the off-pump group remained close to the baseline level. Both groups had improved to the preoperative creatinine clearance values on follow-up at 4 weeks. It was concluded that off-pump surgery provided better renal protection than the conventional on-pump technique in patients with preexisting non-dialysis-dependent renal dysfunction.

Off-pump coronary artery bypass graft surgery in California, 2003 to 2005

BACKGROUND

The impact of off-pump coronary artery bypass graft surgery (OPCAB) on operative mortality compared to conventional coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CCB) has not been clarified.

METHOD

Patient clinical characteristics were compared between OPCAB and CCB for isolated CABG surgeries in 2003 to 2005 using data from the California CABG outcomes reporting program. A propensity score method and logistic regression models were used to compute propensity-adjusted operative mortality for patients undergoing OPCAB or CCB.

RESULTS

Of 57,284 isolated CABGs, 13,515 (22.9%) were OPCAB. Compared to CCB, OPCAB patients were older, more females/nonwhite, and had a higher prevalence of certain noncardiac risk factors but were fewer with diabetes, acute myocardial infarction, New York Heart Association class IV heart failure or angina, cardiogenic shock, prior cardiac surgery, left main coronary disease, or > or =3-vessel coronary disease (all P < .01). Overall, the propensity-adjusted operative mortalities (PAOMRs) were significantly lower in OPCAB patients compared to CCB patients (OPCAB 2.59% [95% CI 2.52%-2.67%] vs CCB 3.22% [95% CI 3.17%-3.27%]). Off-pump CABG had a protective advantage for all quintile subgroups (all P < .05). However, within the OPCAB cohort, those who converted to CCB intraoperately had higher PAOMR (converters 3.47% [95% CI 3.16%-3.77%] vs nonconverters 2.53% [95% CI 2.46%-2.61%]). Age, female sex, nonwhite race, diabetes, congestive heart failure, prior cadiac surgery, left main disease, and with > or =3 diseased coronary arteries were associated with a higher risk of intraoperative conversion from OPCAB to CCB (all <0.05).

CONCLUSION

OPCAB and CCB patients had significantly different preoperative risk profiles, and OPCAB was associated with lower operative mortality compared to CCB.

On-pump beating heart coronary surgery for high risk patients requiring emergency multiple coronary artery bypass grafting

Background

Cardiopulmonary bypass (CPB) with aortic cross-clamping and cardioplegic arrest remains the method of choice for patients requiring standard myocardial revascularization. Therefore, very high-risk patients presenting with acute coronary syndrome, unstable angina, onset of cardiac decompensation and requiring emergency multiple myocardial revascularization, can have a poor outcome. The on-pump beating heart technique can reduce the mortality and the morbidity in such a selected group of patients and this report describes our clinical experience.

Methods

Out of 290 patients operated for CABG from January 2005 to January 2006, 25 (8.6%) selected high-risk patients suffering from life threatening coronary syndrome (mean age 69 ± 7 years) and requiring emergency multiple myocardial revascularization, underwent on-pump beating heart surgery. The mean pre-operative left ventricle ejection fraction (LVEF) was 27 ± 8%. The majority of them (88%) suffered of tri-vessel coronary disease and 6 (24%) had a left main stump disease. Nine patients (35%) were on severe cardiac failure and seven among them (28%) received a pre-operative intra-aortic balloon pump. The pre-operative EuroScore rate was equal or above 8 in 18 patients (73%).

Results

All patients underwent on-pump-beating heart coronary revascularization. The mean number of graft/patient was 2.9 ± 0.6 and the internal mammary artery was used in 23 patients (92%). The mean CPB time was 84 ± 19 minutes. Two patients died during the recovery stay in the intensive care unit, and there were no postoperative myocardial infarctions between the survivors. Eight patients suffered of transitorily renal failure and 1 patient developed a sternal wound infection. The mean hospital stay was 12 ± 7 days. The follow-up was complete for all 23 patients survived at surgery and the mean follow-up time was 14 ± 5 months. One patient died during the follow-up for cardiac arrest and 2 patients required an implantable cardiac defibrillator. One year after surgery they all had a standard trans-thoracic echocardiogram showing a mean LVEF rate of 36 ± 11.8%.

Conclusion

Standard on-pump arrested heart coronary surgery has higher mortality and morbidity in emergencies. The on-pump beating heart myocardial revascularization seems to be a valid alternative for the restricted and selected cohort of patients suffering from life threatening coronary syndrome and requiring multiple emergency CABG.

Off-pump coronary artery bypass grafting in left ventricular dysfunction

Between August 2004 and May 2006, 124 patients undergoing coronary artery bypass grafting with ejection fractions <or= 35% were randomly assigned to off-pump or conventional procedures. Preoperative characteristics were the same in both groups, except for age and degree of mitral regurgitation. Off-pump coronary artery grafting was carried out using a tissue stabilizer and a single-suture technique; conventional coronary bypass employed cardiopulmonary bypass, moderate hypothermia, and antegrade-retrograde cold blood cardioplegic arrest. There were significantly fewer vessels grafted (3.09 +/- 0.41) in the off-pump group than in those who had a conventional procedure (3.42 +/- 0.86). The rates of mortality, morbidity, balloon pump support, inotropic usage, gastrointestinal bleeding, renal dysfunction, reintubation, as well as intensive care and hospital stay, were significantly lower in the off-pump group. The incidence of perioperative myocardial infarction did not differ significantly between groups. The results of this study indicate that beating-heart coronary bypass is safe and effective in patients with left ventricular dysfunction.

Current Status of Off-Pump Coronary Artery Bypass Surgery

The expanding indications for angioplasty coupled with the successful short and mid-term results of randomized controlled trials of drug-eluting stents have already had an unquestionable impact on the practice of coronary revascularization operations. However, coronary artery bypass grafting remains a major mode of therapy for coronary artery disease. It is likely that surgery will continue to be preferred for more complex subsets and that surgeons will have to continue to maintain good results in patients with more complex problems. Concerns regarding morbidity associated with conventional surgical myocardial revascularization on cardiopulmonary bypass have led to a resurgence of interest in off-pump bypass surgery during the last decade, with the expectation that it would be safer if cardiopulmonary bypass could be avoided. This review summarizes the impact of off-pump bypass surgery in reducing the morbidity and mortality associated with conventional coronary artery bypass on cardiopulmonary bypass by evaluating the current best-available evidence from randomized controlled trials and meta-analyses comparing off-pump surgery with conventional bypass grafting.

Off-pump coronary artery bypass grafting using in situ bilateral skeletonized internal thoracic arteries

OBJECTIVE

All arterial off-pump coronary artery bypass grafting (OPCAB) with in situ bilateral skeletonized internal thoracic arteries (ITAs) may become a standard procedure that would provide better long-term results without affecting early results.

METHODS

Our study included 404 consecutive patients who underwent OPCAB with one or two ITAs. We compared the clinical results of 135 patients who underwent OPCAB using unilateral ITA (UITA group) to those of 269 patients using bilateral ITAs (BITA group).

RESULTS

The average number of distal anastomoses was 3.07 in the UITA group and 3.47 in the BITA group (P < 0.01). Four operative mortalities occurred in the UITA group and two in the BITA group. There were no significant differences in morbidity between the two groups.

CONCLUSION

OPCAB using bilateral skeletonized ITAs is technically feasible, with good early results. Arterial OPCAB using in situ bilateral skeletonized ITAs may become a standard procedure in the future.

Efficacy of intramyocardial injection of angiogenic cell precursors for ischemic cardiomyopathy: a case match study

INTRODUCTION

: The objective of this study is to determine the efficacy of intramyocardial angiogenic cell precursors (ACPs) injection in ischemic cardiomyopathy (ICM).

METHODS

: Twenty-five ICM patients (cell group) underwent intramyocardial ACPs injection. Seventeen ICM patients (control group) treated by medical means were matched with cell group. There was no statistically significant difference between cell and control groups in relation to left ventricular ejection fraction (LVEF) and comorbidities. In the cell group, mean age was 58.4 ± 13.7 years. Mean LVEF was 26.1% ± 7.4%. New York Heart Association (NYHA) class was 2.9 ± 0.6. The ACPs were derived and expanded from autologous blood. The number of cells before injection was 27.4 ± 18.8 million cells. The cells were injected into the nonviable myocardium and hypokinetic segments in the cell group.

RESULTS

: There was no new ventricular arrhythmia. NYHA was improved by 0.9 ± 1.0 (P < 0.001) at 229.9 ± 98.8 days. Six-minute walk test and quality of life assessed by short form-36 improved in the cell group. LVEF was improved in 72% of patients (18 of 25). LVEF improved by 6.4 ± 9.9 points % (P = 0.003) at 290.4 ± 210.3 days. The percentage of infarction area decreased 21.9 ± 17.4 points % at 159 ± 54 days postoperatively. There was no significant improvement of NYHA and LVEF in the control group.

CONCLUSIONS

: For this efficacy study, the NYHA class, quality of life, and six-minute walk test were improved after cell transplantation. The LVEF was also significantly improved in the cell treated group.

Neurocognitive outcomes of off-pump versus on-pump coronary artery bypass: a prospective randomized controlled trial

BACKGROUND

Preliminary reports have documented the safety of off-pump coronary artery bypass graft compared with conventional coronary artery bypass graft surgery. Whereas off-pump coronary artery bypass graft surgery may be associated with improvement in some short-term outcomes, longer-term outcomes and influence on neurocognitive function have not been fully assessed. We examined short-term and intermediate-term neurocognitive and index admission morbidity and mortality after coronary artery bypass surgery performed with and without the use of extracorporeal circulation.

METHODS

We prospectively randomly assigned 201 patients undergoing nonemergent isolated coronary artery bypass graft surgery to conventional coronary artery bypass graft surgery (n = 102) or off-pump coronary artery bypass graft surgery (n = 99). The primary end points of the study were neurocognitive function assessed using a 19-test neurocognitive battery at baseline, discharge, and 6 months. Neurocognitive deficit was defined as a 20% or greater reduction from baseline in at least 20% of the tests. Secondary end points included index admission mortality, stroke, low-output cardiac failure, return to the operating room for bleeding, and postoperative troponin release. Risk ratios and 95% confidence intervals were calculated based on intention-to-treat analysis.

RESULTS

There was no difference in neurocognitive deficit at discharge (discharge versus preoperative: risk ratio, 0.83; 95% confidence interval, 0.65 to 1.07) or at 6 months (6 months versus preoperative: risk ratio, 0.94; 95% confidence interval, 0.70 to 1.28). There was no significant difference in mortality or morbidity between the two groups. The off-pump coronary artery bypass graft group had fewer patients with troponin release than the conventional coronary artery bypass graft group.

CONCLUSIONS

Off-pump coronary artery bypass graft surgery did not result in decreased frequency of neurocognitive deficit. Off-pump coronary artery bypass graft surgery was associated with substantially lower levels of troponin release after surgery.