Beating Heart Revascularization Research Articles

On Pump Beating Heart Coronary Artery Surgery in Patients Requiring Urgent Revascularization.

When acute coronary syndrome patients necessitate immediate revascularization, heart-on-pump coronary artery bypass grafting may be regarded as a viable substitute for conventional on-pump surgery. Our clinical experience and initial outcomes of heart-on-pump coronary surgery in patients with acute coronary syndrome are detailed in this article. This research endeavor was a retrospective analysis that spanned the years March 2011 to August 2023. The sample size comprised 2816 patients who had undergone coronary artery surgery. During this period, the same surgical team performed coronary artery bypass surgery on 411 of these patients, who underwent beating heart surgery while on cardiopulmonary bypass support and without cardioplegic arrest; this was done under emergency conditions. 9.3 ± 2.2 hours elapsed between the initiation of acute myocardial infarction and the commencement of coronary artery bypass grafting (CABG). A mean of 4.0 grafts was applied (2.2 ± 1.1). Mortality in hospitals was calculated for sixteen patients. Following surgery, twenty-six patients developed an inadequate cardiac output syndrome. Despite having renal dysfunction, none of the eight individuals needed hemodialysis. The mean duration of stay in intensive care was 3.2 (2.2 ± 1.1) days, while the mean length of hospitalization was 9.2 (4.3 ± 2.4) days. We believe that for high-risk patients with multivascular coronary artery disease who require an emergency coronary artery bypass graft, on-pump beating heart revascularization could be a viable option.

Robotically assisted hybrid coronary revascularization-Masterly technique but is it for the masses?

Hybrid coronary revascularization consists of left internal thoracic artery (LITA) graft to the left anterior descending (LAD) artery and transcatheter revascularization of the non‐LAD stenosis in specific settings to achieve complete coronary revascularization. Technique to perform the LITA to LAD graft has ranged from median sternotomy with cardiopulmonary bypass to robotically assisted totally endoscopic coronary bypass surgery using beating heart revascularization.

Complete revascularization of patients with severe left ventricular dysfunction using mini extracorporeal circulation

Background and aim Mini extracorporeal circulation (MECC) when used as on-pump beating cardiac support during coronary artery bypass grafting can be a better alternative than the conventional cardiopulmonary bypass with aortic cross-clamping and cardioplegic arrest [(conventional cardiopulmonary bypass (cCPB)] in complete revascularization of patients with ejection fraction (EF) Patients and methods A retrospective study was conducted on consecutive 50 patients with chronic stable severely impaired EF ( Results There was no difference in CPB time, perioperative myocardial infarction (MI) or mortality between the two groups. Defibrillation was required in 10% in group I and in 82% in group II, with significantly lower cumulative energy of defibrillation (joules) (P Conclusion On-pump beating heart revascularization of low EF patients using MECC is a safe procedure with better outcome than cCPB in low EF patients. It is followed by a diminished release of ischaemia markers, better early and smooth postoperative course and lower total hospitalization time than after cCPB, and both result in a satisfactory clinical outcome.

Off-Pump Coronary Revascularization preserves Renal Function in patients with Preoperative Non-Dialysis dependent renal dysfunction - A Prospective, Randomized Study

The off-pump coronary artery bypass operation (OPCAB) is a relatively new surgical procedure, which avoids the use of cardiopulmonary bypass and is intuitively considered renoprotective in patients with preoperative normal renal function. However, no prospective, randomized study has been done so far to show whether these benefits may also apply to patients with preoperative non-dialysis dependent renal dysfunction. This first ever prospective, randomized, controlled trial was performed in 50 patients (45 men, mean age 51.2±4.8 yrs) with preoperative nondialysis dependent renal insufficiency, undergoing first-time elective coronary artery bypass grafting. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass (on-pump) or beating heart revascularization (off-pump). Glomerular and tubular functions were assessed upto 48 hrs postoperatively. There were no deaths, strokes or myocardial infarctions in either group. Glomerular function as assessed by creatinine clearance and the urinary microalbumin/creatinine ratio was significantly worse in the on-pump group (p=0.0003 and p=0.008, respectively). Renal tubular function was also significantly impaired in the on-pump group as assessed by the increased N- acetyl glucosaminidase activity (p=0.021). Six patients in the on-pump group developed acute renal failure requiring renal support compared with one in the off-pump group although statistically the comparison was not significant (p=0.098). This study suggests that off-pump coronary artery bypass surgery reduces the likelihood of acute renal failure in patients with preoperative non-dialysis dependent renal dysfunction and thus shortens postoperative intensive care and length of hospital stay.

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

BACKGROUNDOn-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 SETTINGSA retrospective study conducted from August 2009 to October, 2015, in a regional training and research hospital in Turkey.METHODSA 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.RESULTSThe 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.CONCLUSIONWe 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.

Assessing Endothelial Responsiveness After Cardiopulmonary Bypass: Insights on Different Perfusion Modalities

Cardiopulmonary bypass (CPB) exerts several deleterious effects on inflammatory pathways. Most of these can be related to an endothelial insult leading to endothelial dysfunction. To date, the degree of endothelial damage only has been evaluated on a cellular and molecular level, but no studies exist looking at the functional effects of CPB on the endothelium. Previous studies hypothesized a negative effect of continuous flow as opposed to the physiologic pulsatile flow. The aim of the present retrospective study was to investigate how different perfusion modalities during CPB (ie, continuous v pulsatile flow) or its avoidance differently impact endothelial function. Cardiovascular operating room and intensive care unit of a large tertiary University Hospital in Monza, Italy. Flow-mediated dilatation (FMD) of the brachial artery was assessed in 29 patients undergoing elective myocardial revascularization. Ten patients receiving continuous-flow CPB, 10 receiving pulsatile-flow CPB, and 9 scheduled for beating-heart revascularization were studied. Patients were studied at baseline (after induction of general anesthesia), after CPB upon intensive care unit (ICU) admission after surgery, and on the first postoperative day before discharge from the ICU (on average, 24 hours after CPB discontinuation). The continuous-flow CPB group demonstrated a significant reduction in FMD after CPB, (12.8% ± 9.7% v 1.6% ± 1.5%, p<0.01), which lasted up to the first postoperative day (5.9% ± 4.1%). On the other hand, FMD did not change in the pulsatile-flow group (12.5% ± 10.5%, 11.0% ± 7.2%, and 16.6% ± 11.7%, respectively). FMD also was unaffected in the beating-heart group, thus suggesting a direct effect of CPB itself on endothelial function. In conclusion, in this study population of adult patients undergoing elective coronary revascularization, continuous-flow CPB markedly impaired endothelial function, although this was not the case with pulsatile-flow CPB. This study posed the rationale for further investigations on the potential value of FMD to predict cardiovascular events in these patients.

The Lower End Sternal Split (LESS) Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) approach: A safe and less invasive option for beating heart revascularization – long-term-results

The Lower End Sternal Split (LESS) Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) approach: A safe and less invasive option for beating heart revascularization – long-term-results

Ventricular arrhythmic disturbances and autonomic modulation after beating-heart revascularization in patients with pulmonary normotension

De-novo ventricular arrhythmias are potentially life-threatening complications after beating-heart revascularization (off-pump CABG). Whether pulmonary hypertension can influence initiation of ventricular arrhythmias through increased sympathetic activity is controversial. In order to determine the influence of pulmonary hypertension on its relative contribution to ventricular arrhythmia, we first had to define the role of cardiac autonomic modulation in patients with pulmonary normotension. We aimed to observe how parameters of linear and nonlinear heart rate variability are changed pre- and postoperatively in patients with pulmonary normotension undergoing off-pump CABG. Fifteen-minute ECG recordings were collected before and after off-pump CABG in 54 patients with multivessel coronary artery disease and pulmonary normotension to determine linear (TP, HF, LF, LF:HF ratio) and nonlinear detrended fluctuation analysis (alpha1, alpha2) and fractal dimension (average, high and low) parameters of heart rate variability. Arrhythmia was monitored preoperatively in 24-hour Holter recordings and postoperatively by continuous monitoring and clinical assessment. Deterioration from simple (Lown I-II) to complex (Lown III-V) ventricular arrhythmia was observed in 19 patients, and improvement from complex to simple arrhythmia in five patients (P = 0.022). Patients with postoperative deterioration of ventricular arrhythmia had preoperatively significantly lower values of TP, HF and LF (P = 0.024-0.043) and postoperatively significantly higher values on the low fractal dimension index (P = 0.031) than patients with postoperative improvement of arrhythmia. Patients experiencing postoperative deterioration of ventricular arrhythmia already have impaired autonomic regulation before surgery. Higher postoperative values on the low fractal dimension index indicate that sympathetic predominance with or without concomitant vagal withdrawal is the underlying neurogenic mechanism contributing to ventricular arrhythmia.

Assessment of Nonlinear Heart Rate Dynamics after Beating-Heart Revascularization

Advanced nonlinear methods of measuring heart rate variability (HRV) derived from the mathematics of complex dynamics and fractal geometry have provided new insights into the abnormalities of heart rate behavior in various pathologic conditions. These methods have provided additional prognostic information compared with traditional HRV measures and clearly have complemented the conventional linear methods. Knowledge about the behavior of complex cardiac dynamics indices after different cardiac procedures is very limited, however. We aimed to clarify how nonlinear heart rate dynamics are affected by beating-heart revascularization (off-pump coronary artery bypass graft [CABG] surgery) within the first week after the procedure. Included in the study were 66 patients who had isolated stable multivessel coronary artery disease and were in normal sinus rhythm. The patients were on chronic beta-blocker therapy and were scheduled for off-pump CABG. We performed 15-minute high-resolution electrocardiographic recordings preoperatively and on the third and seventh postoperative days to assess linear and nonlinear heart rate dynamics. Frequency-domain measurements, detrended fluctuation analysis (DFA) with short-term (<or=11 beats, alpha1) and long-term (>11 beats, alpha2) correlation properties of RR-intervals, and fractal dimension (FD) measurements (average, high, and low) were made. Arrhythmia was monitored preoperatively with 24-hour Holter recordings, postoperatively by continuous monitoring for the first 4 days after the procedure, and subsequently by clinical monitoring; 24-hour Holter recordings were obtained again on the seventh postoperative day. We used the paired-samples Student t test, the Mann-Whitney U test, and the Fisher exact test for statistical analyses. Differences in arrhythmia occurrence before and after the procedure were tested with the Wilcoxon signed rank test and the McNemar test. A P level < .05 was considered statistically significant. Values for all frequency-domain parameters decreased significantly after off-pump CABG (P< .001). Values for the alpha1 and high FD parameters decreased significantly after the procedure (P= .028 and .001, respectively), whereas alpha2 increased significantly (P= .023). DFA alpha1 was significantly lower in patients with postoperative atrial fibrillation than in patients remaining in sinus rhythm (mean +/- SD, 0.79+/-0.32 versus 1.13+/-0.45 [P= .003] on the third postoperative day; 0.89+/-0.31 versus 1.22+/-0.34 [P< .001] on the seventh postoperative day), whereas low and average FDs were significantly higher (1.84+/-0.16 versus 1.68+/-0.19 [P= .003] on the third postoperative day and 1.77+/-0.18 versus 1.66+/-0.17 [P= .01] on the seventh postoperative day for the low FD; 1.83+/-0.09 versus 1.76+/-0.10 [P= .011] on the third postoperative day and 1.80+/-0.11 versus 1.73+/-0.10 [P= .014] on the seventh postoperative day for the average FD). The low FD was significantly higher on the third postoperative day in patients with postoperative deterioration of ventricular ectopy than in patients with improved ventricular ectopy (1.74+/-0.17 versus 1.48+/-0.08, [P= .03]). The decreases in alpha1, average FD, and high FD indicate that a profound decay of cardiac complexity and fractal correlation can be observed after off-pump CABG. Furthermore, a more extensive impairment of nonlinear indices was observed in patients who developed postoperative arrhythmias than in those who remained in stable sinus rhythm. Our findings suggest that the postoperative hyperadrenergic setting acts as a preliminary condition in which both reduced and enhanced vagal activity may predispose patients to arrhythmia, indicating that postoperative rhythm disturbances are an end point associated with divergent autonomic substrates.

Ventricular Repolarization Dynamicity and Arrhythmic Disturbances after Beating-Heart and Arrested-Heart Revascularization

Arrhythmias attributable to altered autonomic modulation of the heart, with elevated sympathetic and depressed vagal modulation, occur to a similar extent after surgery performed on beating or arrested hearts. Coronary artery bypass grafting (CABG) with cardiopulmonary bypass has been associated with more frequent occurrence of arrhythmic events than surgery performed without CABG, even with comparable levels of postoperative cardiac autonomic (dis) regulation after arrested- and beating-heart revascularization. We explored the effects of arrested- and beating-heart revascularization procedures on the dynamics of ventricular repolarization and on increased postoperative arrhythmic events. Study participants included 57 CABG patients; 28 underwent on-pump and 29 underwent off-pump procedures. The 2 groups were comparable regarding clinical and postoperative characteristics. With high-quality 15-minute digital electrocardiograms, we assessed ventricular repolarization dynamics using RR and QT intervals and analyzed QT variability (QTV) and QT-RR interdependence. RR and QT intervals were determined from stationary 5-minute segments. QT-interval variability was determined by a T-wave template-matching algorithm. We used linear regression to compute the slope/correlation of the QT/RR interval. The Fisher exact test, nonpaired t-test, and ANOVA were applied to test the results; P <.05 was considered significant. Postoperative arrhythmic events were significantly more frequent in both groups. One week postoperatively these events were significantly more frequent in the on-pump group. In both groups, the RR interval was shorter after CABG (P <.001). The QT variability index increased from -1.2 + or - 0.6 to -0.8 + or - 0.4 after off-pump CABG and from -1.3 + or - 0.5 to -0.5 + or - 0.6 on day 4 after surgery (P <.05), further deteriorating to -0.2 + or - 0.6 one week after CABG in the on-pump group only (P <.05). QT-RR correlations decreased from 0.39 to 0.24 in the off-pump vs 0.34 to 0.17 in the on-pump group (P <.05), and in both groups they remained significantly reduced for as long as 4 weeks after CABG. For both on- and off-pump CABG, beat-to-beat heart-rate changes and rate-dependent ventricular repolarization adaptation showed disparities that worsened after surgery. The observed repolarization lability after CABG procedures seems to be transient but more pronounced after on-pump CABG. The association of arrhythmic events with ventricular repolarization lability changes in the setting of faster heart rates offers novel insights into the mechanisms of perioperative proarrhythmia after beating- and arrested-heart revascularization.

Effects of Beating- versus Arrested-Heart Revascularization on Cardiac Autonomic Regulation and Arrhythmias

Altered autonomic regulation after cardiac operations precipitates cardiac arrhythmias, affects repolarization, and increases the risk of sudden cardiac death. We sought to clarify how the 2 different techniques of coronary artery bypass grafting (CABG), namely conventional CABG using cardiopulmonary bypass (on-pump) and beating-heart CABG without cardiopulmonary bypass (off-pump), affect cardiac autonomic regulation and arrhythmic disturbances postoperatively. We included 57 consecutive patients, 28 in the on-pump group and 29 in the off-pump group. The electro-cardiographic recordings were performed on the preoperative day and the fourth, seventh, and twenty-eighth day after operation. Fifteen-minute digital recordings were taken; one channel was used to record electrocardiogram and the other breathing. Detailed analyses of arrhythmia, heart rate, and heart rate variability indices were performed on respective days to assess sympathetic and parasympathetic modulation of the heart and relate it to detected arrhythmic disturbances. Total power, low-frequency power, which indicates baroreceptor-mediated sympathetic modulation, and high-frequency power, indicating parasympathetic vagal modulation, declined significantly in both groups after CABG (P < .001); however, 7 days after CABG, total and high-frequency power were better preserved in the off-pump group. Mean RR interval was longer in the off-pump group at 7 (P= .006) and 28 days (P= .008) after surgery. The total incidence of arrhythmic events was higher in the on-pump group on the seventh day (P = .017, adjusted odds ratio = 8.6, 95% confidence interval 1.4-80.3). The results show profound impairment of cardiac autonomic regulation after CABG, showing better preserved cardiac autonomic modulation 7 days after beating-heart revascularization. Evidence suggests that slower restoration of heart rate and increased incidence of arrhythmic events after CABG using cardiopulmonary bypass are the result not only of impaired cardiac autonomic regulation but also of the involvement of additional factors of nonautonomic origin.

Temporary Right Heart Support With Percutaneous Jugular Access

Temporary right heart bypass has shown to improve hemodynamic stability and safety in beating heart revascularization. We sought to evaluate feasibility and safety of a right ventricular assist device percutaneously implanted in the right jugular vein. The A-Med jugular coaxial cannula (A-Med Systems Inc, West Sacramento, CA) is designed for percutaneous implantation. Blood from the right heart is drained through the outer tube of this two-cannula device to a microcentrifugal pump and returned into the pulmonary artery through the inner tube. In 10 patients scheduled for elective coronary bypass grafting without cardiopulmonary bypass, a total of 27 coronary anastomoses were performed with right heart support. Arterial pressure was significantly higher with right heart support when the heart was dislocated to access posterior and posterolateral anastomosis sites. Implantation through the right internal jugular vein was feasible without complications in all patients and facilitated the procedure. This initial study suggests safety and feasibility of temporary right heart support using percutaneous jugular access for posterior and posterolateral coronary bypass grafting.

Beating heart revascularization with minimal extracorporeal circulation in patients with a poor ejection fraction.

Coronary artery bypass grafting with cardioplegia in patients with a low ejection fraction carries a risk of myocardial ischemia. Beating heart surgery is associated with hemodynamic changes when the heart is manipulated. We assessed an alternative: minimal extracorporeal circulation for coronary artery bypass grafting on a beating heart in patients with a poor ejection fraction. From January 2000 to January 2002, 50 patients with an ejection fraction of less than 35%, who represented 10% of all patients undergoing coronary artery procedures, underwent revascularization on a beating heart with assistance. We used a closed cardiopulmonary bypass system with a centrifugal pump without reservoir, and the surgical strategy was modified to avoid aortic cross-clamping and to decrease bypass time. The main preoperative characteristics were: age (mean +/- SD) of 64 +/- 11.2 years (range, 41-87 years), 35 male patients (70%), mean left ejection fraction of 24.8% +/- 11.2%, and a mean EuroSCORE of 5.8 +/- 2.7. Revascularizations of 146 distal anastomoses (2.9 +/- 0.7 grafts/patient) were completed. Twelve percent were double bypass, 86% were triple bypasses, and 2% were quadruple bypasses; the mean bypass time was 64.2 +/- 26.2 minutes. The mean graft number was 2.9, and the hospital mortality was 2%. Perioperative hematocrit levels were 30.1%, and 26% of patients received transfusions. Postoperative data showed a median extubation time of 9 hours, a median intensive care unit stay of 48 hours, and a hospital stay of 8 +/- 2 days. Postoperative complications included inotropic support (14%), cerebrovascular events (2%), reoperation for homeostasis (4%), delayed sternal closure (2%), and mediastinitis (2%). Peak troponin Ic level remained a low 2.4 +/- 1.9 g/mL. Follow-up at 6 months was complete with 1 late mortality and with a mean ejection fraction of 30.5% +/- 10.8% for the survivors. Coronary revascularization on a beating heart with extracorporeal assistance can be done in patients with a low ejection fraction. It avoids the myocardial injury associated with aortic cross-clamping and allows safe and complete coronary revascularization.

Effect of Off-Pump and On-Pump Coronary Artery Bypass Grafting on Renal Function

Background. Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) has the risk of renal dysfunction. The cause of renal dysfunction after CPB is multifactorial, such as nonpulsatile flow, renal hypoperfusion, hypothermia, and duration of CPB. This study compared off-pump technique with on-pump technique on renal function in patients who underwent CABG. Methods. Sixty patients with normal preoperative renal functions undergoing CABG were randomly assigned to conventional revascularization with CPB (on-pump) or beating heart revascularization (off-pump). Renal functions were assessed up to 10 days postoperatively. Results. Creatinine clearance was found to be significantly higher in the off-pump group than in the on-pump group (p < .05). The off-pump group had significantly less increase in creatinine levels when compared with the on-pump group (p < .05). The free water clearance values decreased similarly in both groups; however, the recovery was more prompt in the off-pump group (p < .05). No significant differences were found in the prevalence of postoperative hemodialysis. Conclusion. The off-pump technique may provide a positive contribution and sufficient protection on postoperative renal functions in patients undergoing CABG.

Results of a phase one study on robotically assisted myocardial revascularization on the beating heart

BackgroundThe objective of this study was to evaluate the feasibility of computer assisted myocardial revascularization on the beating heart. MethodsTen patients underwent at least one robotically assisted internal mammary artery (IMA) anastomosis utilizing the da Vinci surgical system (Intuitive Surgical, Inc, Mountain View, CA) performed through an open incision as part of standard multivessel off pump revascularization. Following chest closure a selective IMA angiogram was performed to assess patency. Three month follow-up included a stress echocardiogram. ResultsThere were 12 anastomoses performed in 10 patients. The average age was 61 years with a mean ejection fraction of 56%. No patient required inotropic support. Eight of 10 patients were found to have fully patent IMA anastomoses by angiogram. One patient was noted to have an occluded left anterior descending coronary artery distal to the anastomosis and one had occlusion at the anastomosis. Both patients had immediate manual revision of the anastomosis. One patient who required anastomotic revision experienced postoperative myocardial infarction and sternal wound infection requiring pectoralis flaps. ConclusionsBecause robotic instrumentation is meant for closed chest procedures, there were major issues with positioning of the robotic arms in this study since the chest was open. Although two patients required anastomotic revision, there were no complications or technical failures related to the robotic system. Thus, based upon this study robotically assisted beating heart revascularization appears to be feasible, safe, and effective. Further evaluation will be necessary to determine the role of robotically assisted totally endoscopic coronary artery bypass on the beating heart in the United States.

Beating heart revascularization with or without cardiopulmonary bypass: evaluation of inflammatory response in a prospective randomized study

Beating heart revascularization with or without cardiopulmonary bypass: evaluation of inflammatory response in a prospective randomized study

Beating versus arrested heart coronary revascularization: evaluation by cardiac troponin I release

Background This prospective randomized study aimed to compare beating and arrested heart revascularization in patients undergoing first elective coronary artery bypass graft, with cardiac troponin I release used to evaluate myocardial injury. Methods Seventy patients were randomly assigned to a beating or arrested heart revascularization group. Cardiac troponin I concentrations were measured in serial venous blood samples drawn preoperatively in both groups: after aortic unclamping at 6, 9, 12, and 24 hours in the arrested heart group and after the last anastomosis at 6, 9, 12, and 24 hours in the beating heart group. Analysis of covariance with repeated measures was performed to test the effect of group and time on cardiac troponin I concentration. Results The total amount of cardiac troponin I released was higher in the arrested heart revascularization group than in the beating heart revascularization group (8.25 ± 6.16 vs 3.18 ± 4.75 μg, p < 0.0001). Cardiac troponin I concentrations were significantly higher in the arrested heart group at hours 6, 9, 12, and 24 than in the beating heart group ( p < 0.0001). Conclusions The lower release of cardiac troponin I in the beating heart revascularization group indicates that conventional coronary artery bypass graft with cardioplegic arrest causes more damage to the heart than off-pump myocardial revascularization.

Beating heart revascularization with or without cardiopulmonary bypass: evaluation of inflammatory response in a prospective randomized study

Objective On-pump beating heart coronary artery surgery provides the opportunity to examine the isolated effect of cardiopulmonary bypass. This prospective randomized study compares the early clinical outcomes and inflammatory response of patients undergoing elective on-pump and off-pump beating heart coronary artery bypass grafting. Method and patients Thirty-seven consecutive patients undergoing elective coronary artery bypass grafting were recruited from a pool of 73 patients, with 19 patients randomized to on-pump beating heart surgery and 18 patients to off-pump coronary bypass surgery. Intraoperative events and postoperative outcomes were recorded. Plasma levels of interleukin-6, interleukin-8, and interleukin-10, tumor necrosis factor-alpha, and vascular cell adhesion molecule-1 were measured before the operation, intraoperatively, after the operation, and 4, 24, and 48 hours thereafter. Results There was no significant difference in clinical outcomes between the 2 groups. The operating time was longer and consumption of platelets was greater for the on-pump beating heart group. There was no postoperative mortality or major complication in either group. There was significant elevation in the levels of interleukin-6, interleukin-8, and interleukin-10 and tumor necrosis factor-alpha during and immediately after the operations in the on-pump beating heart group when compared with the off-pump group. Levels of interleukin-8 ( P = .01) and tumor necrosis factor-alpha ( P = .0004) remained significantly elevated 4 hours after the operation in the on-pump beating heart group. The level of vascular adhesion molecule dropped significantly during the operation but was elevated 4 hours ( P = .026) after the operation in the on-pump beating heart group. Conclusion The use of cardiopulmonary bypass alone without global myocardial ischemia secondary to aortic crossclamping and cardioplegic cardiac arrest can trigger intense inflammatory responses.

Early bypass occlusion after deployment of nitinol connector devices

Background Reducing the negative side effects associated with extracorporeal circulation is the major advantage of off-pump revascularization. However, side clamping of a calcified aorta for proximal anastomoses can cause emboli, resulting in neurologic damage. This problem has been addressed by introducing a mechanical anastomosis device (Symmetry, St Jude Medical) that allows vein-to-aorta anastomosis without manipulating the aorta. This report describes our experience with this device. Methods Between June 2001 and April 2002, 77 connectors (1.3 per patient) were deployed in 61 patients (51 men and 10 women; mean age, 68 ± 8.6 years) undergoing off-pump coronary artery bypass grafting or beating-heart revascularization. Intraoperative quality assessment included transit-time flow measurement (Medistim) and indocyanine green–based angiography (Spy, Novadaq). Results The surgeons were meticulously trained in loading of the device. No postoperative neurologic deficits were detected. Fifty-three patients had an uneventful course. However, 8 (13.1%) patients with 12 implanted connectors were symptomatic within 8 months (1 day to 8 months). Angiography revealed significant (95%) stenosis or even occlusion of the proximal vein-to-aorta anastomosis at the level of all connectors. Four patients underwent reoperation (2 dilated-stented and 2 treated with drugs). Conclusion On the basis of these observations, the routine use of the connector was halted at our institution. At the moment, the use of this therapy is reserved for patients with severely calcified aortas with no technical alternative. Further investigations appear necessary to evaluate the clinical patterns of this otherwise promising technology.

Effects of intracoronary shunts on coronary endothelial coating in the human beating heart

Background Local occlusion of coronary arteries during beating heart revascularization leads to injury of the arterial wall especially disturbing the integrity of the endothelium. The aim of this study was to elucidate the effects of intracoronary shunts versus local occlusion with elastic silicone loops on the beating heart in human coronary arteries by scanning electron microscopy. Methods Coronary arteries of patients with dilated cardiomyopathy (n = 4) or ischemic heart disease (n = 8) undergoing heart transplantation were locally occluded either with a silicone loop or with a shunt inserted after arteriotomy. Unmanipulated segments of the coronary arteries served as controls. Integrity of the endothelial lining was observed with scanning electron microscopy. Results Scanning electron microscopy revealed a statistically significant higher injury after shunting compared with controls ( p < 0.001) and vessel loop occlusion ( p < 0.001). There was no difference between both patient groups according to control specimens or after manipulation. Conclusions From this investigation we conclude that insertion of intracoronary shunts during beating heart surgery leads to severe endothelial denudation in human coronary arteries. Therefore, at present we recommend using intracoronary shunts selectively in cases in which critical ischemia or technical difficulties as a result of anatomic conditions are expected during anastomosis and avoiding routine shunt insertion into coronary arteries during beating heart revascularization.