Pump Coronary Artery Bypass Surgery Research Articles

Prophylactic Dialysis in Elderly Patients Undergoing Coronary Bypass Surgery

Renal dysfunction is associated with markedly increased risk for both mortality and morbidity in patients undergoing coronary artery bypass surgery (CABG), especially in elderly patients. In the current study, we aimed to determine the impact of prophylactic preoperative hemodialysis on operative outcome in patients with mild renal dysfunction. Between March 2002 and May 2005 a total of 64 patients, all of whom were more than 70 years of age and with preoperative creatinine levels greater than 2 mg/dL, underwent primary elective on pump coronary artery bypass surgery. The mean age was 76.3 +/- 6.4 (range 70-83). The patients were prospectively allocated into two groups. Group A was the dialysis group (31 patients) and preoperative prophylactic hemodialysis was carried out in all patients. Group B (33 patients) was taken as a control group without preoperative hemodialysis. During the present study, 10 patients died (15.6%) in the hospital. In the postoperative period mean levels of creatinine were found to be decreased in dialysis group. (2.3 +/- 0.8 mg/dL vs. 3.4 +/- 0.2 mg/, P = 0.037). The incidence of overall morbidity (such as acute renal failure, need of postoperative dialysis, low cardiac output and multiple organ failure) were also found to be decreased in dialysis group. We conclude from the present study that preoperative renal dysfunction and advanced age increase the risk of mortality and morbidity after on-pump coronary artery bypass surgery. We believe that perioperative prophylactic hemodialysis is an easy and effective method and it decreases both operative mortality and morbidity in elderly patients with renal dysfunction.

Does Predictors of Preload Measured from Continuous Right Ventricular End-diastolic Volume Index Monitored Pulmonary Artery Catheter Reflect Stroke Volume Index in Off Pump Coronary Artery Bypass?

Background: It is important to assess cardiac preload for management of patients undergoing off pump coronary artery bypass surgery (OPCAB). Recently, several studies have documented the good correlation between right ventricular end-diastolic volume index (RVEDVI) and stroke volume index (SVI), compared with cardiac filling pressures. However, none of these studies have evaluated relationship between predictors of preload and SVI measured with volumetric pulmonary artery catheter during OPCAB. The correlation of continuous RVEDVI and SVI measured with volumetric pulmonary artery catheter during OPCAB was evaluated in this study. Methods: Fifty three patients undergoing OPCAB were included. Hemodynamic parameters were measured 10 min after induction (T1), 10 min after Y-graft formation started (T2) and 10 min after sternum closure (T3). The correlation of parameters were assessed by simple linear regression. Results: Central venous pressure (CVP) and pulmonary artery occlusion pressure (PAOP) did not correlate with SVI during OPCAB. On the other hand, a statistically significant result was found between RVEDVI and SVI at T2 (r2 = 0.133, P = 0.007) and T3 (r2 = 0.380, P ＜ 0.000). But RVEDVI and SVI were weakly correlated. And at T1, RVEDVI and SVI did not correlate. Conclusions: RVEDVI is a more reliable predictor of preload compared to CVP and PAOP during OPCAB. But in post-induction period (T2), RVEDVI did not correlate with SVI.

Our experiences with off pump coronary artery bypass surgery: retrospective analysis of 2587 patients

Between October 1999 and June 2006 3490 isolated coronary surgeries were performed at our department, among them 2587 beating heart procedures. This technique became the predominant method of coronary revascularisation in our institution. Since 2004 99.4% of isolated coronary patients were operated off pump. The average age of the patients was 65.3 years (29–91), 30.4% of the patients was older than 70 years. The majority of the patients had medium predicted preoperative risk, the average EUROSCORE value was 4.7 (0–13). The percentage of urgent operations (within 24 hours) was 10.3%. The indication for prophylactic use of intraaortic balloon contrapulsation (3.9%) was haemodynamic instability, poor myocardial function or critical coronary anatomy. In the majority of the cases aortocoronary shunt was used to avoid myocardial ischaemia during the operation. The average number of bypass grafts was 3.05 (1–6), the left internal mammarial artery was used in 96% and the right internal mammarial artery in 24% of the cases. The conversion rate to extracorporal circulation in the last 3 years was 0.9%. In the postoperative periode 16% of patients needed positive inotropic support, 91% of patients were extubated within 8 hours. 6 patients required immediate recatheterization because of acute ischaemic events. The average hospital stay was 7.9 days. The early mortality was 1.89%. Our data suggest that off pump technique provides good results with low mortality and morbidity in all patients including high risk cases.

Off-pump coronary artery surgery is the future of coronary bypass surgery?

Objective: In the last few years, off-pump coronary artery bypass grafting (OPCAB) has gained widespread diffusion and being increasingly reported to show better outcomes compared with conventional on pump coronary artery bypass surgery, despite the lack of sufficient evidence from randomized trials. We examined our early experience with this technique mainly in high risk, elderly and multivessel coronary artery disease patients.

Effect of Preoperative Omitting Angiotensin-converting Enzyme Inhibitor on Hemodynamics in Patients Undergoing Off Pump Coronary Artery Bypass Surgery

Background: Angiotensin-converting enzyme inhibitors (ACE-I) have been widely used for cardiac patients. This study investigated the effect of omitting ACE-I medication on hemodynamics during induction of anaesthesia and operation in patients chronically treated with ACE-I undergoing off pump coronary artery bypass graft surgery (OPCAB). Methods: Sixty patients scheduled for OPCAB were included in this study. Patients not treated with ACE-I were included in control group (Group 1, n = 20). And then, patients treated with ACE-I more than 4 weeks were randomly divided into two groups: continuing group including patients who continued ACE-I medication until the morning of surgery (Group 2, n = 20) and discontinuing group including patients who discontinued ACE-I one day before the surgery (Group 3, n = 20). Norepinephrine (8μg/ml) was infused when systolic blood pressure decreased below 90 mmHg during induction and operation. Amount of norepinephrine infused and hemodynamic data were recorded. Results: Significantly larger amount of norepinephrine was infused in Group 2 than in other two groups during obtuse marginal artery anastomosis. Total amount of norepinephrine infused during the all coronary anatsomosis was significantly larger in Group 2 than those values in other two groups. Conclusions: Continuing ACE-I treatment until the morning of surgery significantly increased the use of norepinephrine during the anastomosis. In contrast, there was no significant difference in the use of norepinephrine between Group 1 and Group 3. Discontinuing ACE-I before the surgery may helpful to maintain hemodynamics stable during coronary anastomosis in OPCAB. (Korean J Anesthesiol 2007; 52: 34～41)

Off pump coronary artery bypass surgery (OPCAB) is beneficial in renal dysfunction

Off pump coronary artery bypass surgery (OPCAB) is beneficial in renal dysfunction

Clampless Anastomosis: Novel Device for Clampless Proximal Vein Anastomosis in OPCAB Surgery--The Initial Spyder Experience

The Spyder is a novel device that enables the attachment of a vein to the aorta by compliant, interrupted anastomosis; this minimizes aortic manipulation during off pump-coronary artery bypass (OPCAB) surgery. Its use may reduce transcranial Doppler signals recorded during CABG. We performed 250 anastomoses in 160 OPCAB cases in many centers and recorded efficiency and efficacy data. There were no adverse events noted during the operative period. In a subset of patients in one center, flow (n = 48) and transcranial Doppler signals (n = 22) were measured. We found the device to be a useful adjunct for minimally invasive CABG surgery.

Le pontage coronaire à cœur battant : à propos de 1080 patients

A consecutive cohort including 1080 patients undergoing "off-pump" myocardial revascularization was reviewed. An average of 2,22 bypass/patients was performed. The death-rate during the first 30 days after surgery was 0,65%. Four cases needed cross-over to on-pump. The postoperative events were: need of inotropic drugs (2,7%), atrial fibrillation (12,4%), myocardial infarction (6,6%). The extubation was performed before the first postoperative 24 h in 91,9% of cases. The majority of patients was discharged from hospital before 8 days after surgery. Off pump coronary artery bypass surgery exhibit good results for most of the patients even if they present multiple vessel disease and high operating risk.

Pulmonary hemodynamics and gas exchange in off pump coronary artery bypass grafting

To investigate the influence of cardiopulmonary bypass on pulmonary hemodynamics and gas exchange. Low risk patients admitted for elective coronary artery bypass grafting were randomized to either on (n=25) or off pump (n=25) surgery. Central hemodynamics, gas exchange, and venous admixture were studied during and up to 20 h after surgery. There was no difference in pulmonary vascular resistance index (P=0.16), right ventricular stroke work index (P>0.2), mean pulmonary artery pressure (P>0.2) or pulmonary capillary wedge pressure (P>0.2) between groups. Soon after surgery there was a tendency towards higher cardiac index (P=0.07) in the off pump group. Arterial oxygen tension (P>0.2), hematocrit (P>0.2), venous admixture (P>0.2), and arterial-venous oxygen content difference (P=0.12) did not differ between groups. This prospective, randomized study showed no difference in pulmonary hemodynamics, pulmonary gas exchange, and venous admixture, in low risk patients undergoing off pump compared to on pump coronary artery bypass surgery.

The effect of right coronary artery stenosis on right ventricular function in patients undergoing off pump coronary artery bypass surgery

The effect of right coronary artery stenosis on right ventricular function in patients undergoing off pump coronary artery bypass surgery

Comparative Study of Perioperative Infusion of Diltiazem and Nicorandil on Myocardial Protection During OPCAB Surgery

We compared the effects of continuous intravenous infusions of nicorandil and diltiazem on left ventricular function, haemodynamics and as anti-ischaemic and anti-arrhythmic agents in 50 patients undergoing off pump coronary artery bypass surgery using arterial conduits. The patients were randomized into two equal groups to receive diltiazem or nicorandil. Both the drugs were given as a continuous infusion in the dose of 1 microg/kg/min starting at induction and continued for 24 hours postoperatively. Haemodynamic parameters, cardiac enzyme levels and use of vasoactive agents were studied and compared using ANOVA, unpaired "t" and Fisher's exact tests. The two groups did not differ with respect to preoperative and operative data. Diltiazem group showed lower cardiac index (2.66+/-0.8 and 2.27+/-0.89 L/min/m2) as compared with nicorandil group (3.16+/-0.79 and 2.97+/-1.01 L/min/m2) during revascularisation of anterior (P=0.03) and inferior (P=0.01) circulation respectively. The systemic vascular resistance index was higher (2290+/-699 and 2545+/-911 dyne.sec.cm(-5).m2) in diltiazem group as compared with nicorandil group (1822+/-532 and 1877+/-548 dyne. sec.cm(-5).m2) during revascularization of anterior (P=0.01) and inferior (P=0.002) circulation respectively. The mean pulmonary artery pressure was significantly higher in nicorandil group as compared with diltiazem group during revascularisation of anterior circulation (22.5+/-4.9 and 18.1+/-6.8 mmHg, P=0.01). The patients in the diltiazem group maintained a lower heart rate throughout the study period, but the difference was not statistically significant. None of the patients exhibited any arrhythmia except one in nicorandil group, who developed supraventricular arrhythmia 24 hours postoperatively. Cardiac enzyme levels were found to be similar in the two groups. The present study demonstrates that the anti-ischemic and antiarrythmic effects of diltiazem and nicorandil are comparable, but diltiazem causes a decrease in cardiac index and increase in systemic vascular resistance index during revascularization of anterior and inferior circulation.

The Effect of Right Coronary Artery Stenosis on Right Ventricular Function in Patients Undergoing off Pump Coronary Artery Bypass Surgery

Background: Right ventricular (RV) function has important prognostic implications in off-pump coronary artery bypass surgery (OPCAB). This study investigated the effect of the extent of right coronary artery (RCA) stenosis on RV function and hemodynamics in patients undergoing OPCAB. Methods: Fifty five patients undergoing OPCAB were divided into two groups according to the degree of RCA stenosis; patients with RCA stenosis of ＜ 70% (Group 1, n = 26) and 80% (Group 2, n = 29). RV ejection fraction (RVEF) and RV volumetric parameters were measured using thermodilution technique. Hemodynamic variables were recorded 5 min after induction (T1), 5 min after stabilizer application for anastomosis of the left anterior descending coronary artery (T2), the obtuse marginalis branch (T3) and the RCA (T4) and 5 min after sternum closure (T5). Results: There were no significant differences in hemodynamic variables between two groups during all study periods except in RVEF. RVEF was significantly greater at T2 and T5 in Group 1 than in Group 2. It decreased significantly at T4 in Group 1 and at T3 and T4 in Group 2 compared to values at T1. Conclusions: RVEF significantly decreased at T2 and T5 in group 2 patients. Other variables affecting the RV function such as cardiac output, pulmonary vascular resistance and RV end diastolic volume index showed no differences between the two groups. These findings suggest that the degree of RCA stenosis has contributed to the decrease in RVEF in patients undergoing OPCAB.

Off pump coronary artery bypass surgery provides better than expected results in the high risk coronary artery bypass graft population

Abstract Introduction: Comparative outcomes, risks and benefits of off pump versus on pump coronary artery bypass graft (CABG) surgery remain controversial. Factors including advanced age, previous stroke, left ventricular dysfunction and calcific aorta prompted the introduction of the off pump CABG (OPCAB) to our cardiothoracic surgical practice. Methods: We retrospectively reviewed the results of bypass operations performed between January 2000 and December 2003 with respect to predicted and observed mortality rates, as calculated by the Northern New England risk stratification model. Results: Preoperative comorbidities in the CABG versus OPCAB groups showed no difference in age (64 years vs 65.6 p=NS), gender (78% male vs 78% p=NS), body mass index (28.8 vs 28.3 p=NS), diabetes (43% vs 41% p=NS), neurovascular disease (10% vs 11% p=NS), peripheral vascular disease (11% vs 12% p=NS), and chronic obstructive pulmonary disease (29% vs 24% p=NS). From 2000 to 2003, the observed / expected (O:E) mortality rates were 1.49, 0, 0.54, and 0.24 respectively in the OPCAB group compared to 0.65, 1.03, 1.01, and 0.45 in the CABG group. No significant difference was seen in length of stay (8.7 days vs 6.97 p=0.119), postoperative atrial fibrillation (33% vs 35% p=NS), incidence of stroke (2% vs 0% p=0.059), or new onset acute tubular necrosis (10% vs 11% p=NS). YearCABGOPCABnE (%)O (%)O:ENE (%)O (%)O:E20001608.715.630.6579.5714.31.4920011337.737.971.03336.75002002787.597.691.01977.684.170.542003976.933.090.45547.851.850.24N = number; E=expected mortality; O=observed mortality; O:E = observed to expected mortality ratio. Conclusions: The improving observed to predicted mortality over the past four years supports OPCAB as a good approach for coronary revascularization in the higher risk surgical population.

Off pump coronary artery bypass surgery leads to improvement of left ventricular function in patients with significant systolic dysfunction

Off pump coronary artery bypass surgery leads to improvement of left ventricular function in patients with significant systolic dysfunction

Histological aspects of the saphenous vein damage with the use of the symmetry® aortic connector system

The purpose of the present study was to analyze the histological aspects of the saphenous veins after the use of the Symmetry aortic connector in off pump coronary artery bypass surgery (OPCAB). Nineteen consecutive patients who underwent OPCAB surgery and who received one proximal saphenous vein anastomosis using the St Jude aortic Symmetry connector system were evaluated. In each patient one small segment of the saphenous vein was cut before the use of the Symmetry connector (V0), then another segment after (V1). All segments were stored in an acetone-formaldehyde-alcohol solution before examination. Examination of the V0 segments showed non-specific media fibrosis. In V1, 11 segments presented with a complete alteration of the endothelial layer (58%) and 8 with severe lesions (more than 80%). Among all the V1 segments, 8 had a dissection of the media (42%) and one presented with a wall thrombus. These results suggest that the use of the aortic connector can be associated with different types of lesions of the venous wall. Thus, further investigation and especially long-term follow-up are mandatory to evaluate the consequences of such lesions upon the grafts' patency.

Modified distal carotid artery perfusion for combined carotid endarterectomy and off pump coronary artery bypass surgery

Modified distal carotid artery perfusion for combined carotid endarterectomy and off pump coronary artery bypass surgery

Bivalirudin versus heparin and protamine in off-pump coronary artery bypass surgery

Background Bivalirudin is a short-acting direct thrombin inhibitor, with advantages over unfractionated heparin for anticoagulation in cardiac surgery. We hypothesized that bivalirudin is not associated with a clinically important increase in blood loss compared with heparin with protamine reversal in patients undergoing off pump coronary artery bypass (OPCAB) surgery. We also assessed flow with angiography at 3 months using a modified Thombolysis in Myocardial Infarction (TIMI) grade in the grafted coronary arteries. Methods One hundred patients were randomly assigned to receive bivalirudin (0.75 mg/kg bolus, 1.75 mg/kg/h infusion) or heparin (150 to 300 U/kg bolus) with protamine reversal. Results A median of 3 (range, 1 to 5) grafts were inserted per patient. Blood loss for the 12 hours after study drug initiation in the bivalirudin group (median, 793 mL; interquartile range, 532 to 1,214 mL; range, 320 to 4,909 mL; n = 50) was not significantly greater than in the heparin group (median, 805 mL; interquartile range, 517 to 1,117 mL; range, 201 to 2,567 mL; n = 50; p = 0.165). Median graft flow was 3.0 in the bivalirudin group (n = 40) and 2.67 in the heparin group (n = 39; p = 0.047). The bivalirudin group had more patients with grade 3 (ie, full) flow in at least 1 graft (100% versus 90%; p = 0.04), a trend toward more patients with grade 3 flow in all grafts (60% versus 38%; p = 0.06), and more grafts with grade 3 flow (82% versus 67%; p = 0.03). Conclusions Anticoagulation for OPCAB surgery with bivalirudin was feasible without a clinically important increase in perioperative blood loss. Graft flow was better in the bivalirudin patients; the impact of this on clinical outcomes requires a larger study.

Emergency off pump coronary artery bypass surgery in an octogenarian with dextrocardia

Emergency off pump coronary artery bypass surgery in an octogenarian with dextrocardia

Current trends and technique in OPCAB surgery.

Aging of the population, increased surgical risk, and technical improvement have contributed to the recent revival of off pump coronary artery bypass surgery (OPCAB). We present our experience with the systematic use of this technique. Between September 1996 and June 2000, 500 OPCAB procedures were performed at the Montreal Heart Institute (95% of all procedures during time frame, single surgeon). Contraindications were unstable hemodynamics, intramyocardial left anterior descending artery, and reoperation with extensive adhesions. Stabilization was achieved with pericardial sutures and mechanical compression. Surgical strategy was to first bypass the culprit lesion. Anesthetic management consisted of adequate fluid loading and minimal use of alpha-agonist. This cohort was compared to a contemporary cohort of 1,444 patients operated with cardiopulmonary bypass (CPB). Demographics and risk factors were comparable for all. OPCAB patients received more grafts (3.1 +/- 0.9 vs 2.9 +/- 0.7, p = 0.006), conversion rate was low (0.4%), and complete revascularization was achieved in 93%. Operative mortality and perioperative myocardial infarction were comparable in both groups. Transfusion need, CK-MB count, postoperative use of intra-aortic balloon pump, and creatinine increase were less significant in OPCAB. Postoperative hemorrhage, atrial fibrillation, prevalence of cerebrovascular accident, and hospital stay were comparable for both groups. These results are comparable to those currently reported in the literature. OPCAB surgery in the current era has established its safety and short-term efficacy although long-term clinical results are still warranted. Considering the changing pattern in surgical practice, OPCAB surgery should remain a therapeutic option in modern cardiac surgery.

Comparison of three methods of blood conservation in expected bleeders in OPCAB (off pump coronary artery bypass surgery)

Background. Blood conservation has remained a challenge in the field of cardiac surgery, especially since the advent of OPCAB. This has led us to conduct this study to compare the efficacy of desmopressin, aprotinin bolus doses and aprotinin continuous infusion in controlling the periorative bleeding.