Pro: beating-heart surgery for coronary revascularization: is it the most important development since the introduction of the heart-lung machine?

Off-Pump Coronary Artery Bypass Surgery

Off-pump coronary artery bypass surgery has been adopted enthusiastically worldwide. However, despite more than 6 years’ experience and refinement, many surgeons use it only sporadically and some hardly at all. This reluctance persists despite support for the procedure because of the lack of properly designed risk models and/or randomized studies. Although it has not been overwhelmingly shown that off-pump surgery is superior to the conventional on-pump procedure, the technique has its place in our specialty. It has been shown to be better for noncritical end points in selected patients in the hands of selected surgeons. That there are differences in surgical skill among surgeons is something we all know but rarely discuss in public. Until now, disparities in skill have been most salient with uncommon and extraordinarily challenging operations. Perhaps the off-pump procedure should be regarded as the “challenging” aspect of coronary artery bypass surgery, and self-restraint may need to remain in force if we are to continue to achieve the highest level of clinical excellence.

Smith predictor-based robot control for ultrasound-guided teleoperated beating-heart surgery

Performing surgery on fast-moving heart structures while the heart is freely beating is next to impossible. Nevertheless, the ability to do this would greatly benefit patients. By controlling a teleoperated robot to continuously follow the heart's motion, the heart can be made to appear stationary. The surgeon will then be able to operate on a seemingly stationary heart when in reality it is freely beating. The heart's motion is measured from ultrasound images and thus involves a non-negligible delay due to image acquisition and processing, estimated to be 150 ms that, if not compensated for, can cause the teleoperated robot's end-effector (i.e., the surgical tool) to collide with and puncture the heart. This research proposes the use of a Smith predictor to compensate for this time delay in calculating the reference position for the teleoperated robot. The results suggest that heart motion tracking is improved as the introduction of the Smith predictor significantly decreases the mean absolute error, which is the error in making the distance between the robot's end-effector and the heart follow the surgeon's motion, and the mean integrated square error.

Robotically Assisted Beating Heart Totally Endoscopic Coronary Artery Bypass (TECAB). is There a Future?

Objective

Since the introduction of beating heart totally endoscopic coronary artery bypass (TECAB), approximately 400 patients have undergone the procedure worldwide. Despite satisfactory results and reduced morbidity, the procedure has not gained wide acceptance. This report describes the authors’ experience of beating heart TECAB with robotic assistance and the potential adoption of this technique for the future.

Methods

Between July 2004 and December 2005, 93 patients underwent successful for beating heart TECAB (47 males and 46 females). Mean age was 67.4 + 12.3 years. Fifteen (13.8%) were excluded or converted intraoperatively to thoracotomy for completion of procedure. The procedure was performed through port incisions for the robotic arms and the endostabilizer. Single or bilateral internal thoracic arteries were used as conduits. Anastomoses were done using surgical U-clips. Eighteen (19.4%) patients underwent planned hybrid revascularization. Eighty-four (90.3%) patients underwent computed tomography or conventional angiography.

Results

Details of 93 completed revascularization cases are summarized in the tables. No in-hospital mortality, myocardial infarction, or CVA was noted. Mean operative time was 272.6 + 128.9 minutes (median, 270 minutes). Mean anastomotic time was 13.8 + 3.7 minutes. Mean length of hospital stay was 3.4 + 2.0 days (median, 3 days). At the time of study, 122 of 122 (100%) grafts were found to be patent.

Conclusions

Single- and multivessel beating heart TECAB with or without hybrid revascularization may offer a less invasive approach in a selected group of patients.

Introduction of an OPCAB program aimed at total arterial grafting in a multidisciplinary setting: feasible and safe?

BACKGROUND

The feasibility and the results of the introduction of an off-pump coronary artery bypass (OPCAB) program aimed at total arterial revascularization in a multidisciplinary institution were analyzed. Uniform surgical and anesthetic protocols were established and applied throughout the study period.

METHODS

From March 2003--when the first OPCAB procedure of the program was performed--to July 2004, the data related to all the coronary artery bypass grafting procedures (N = 408) were prospectively recorded. The program was divided into two stages: the purpose of the first stage was to perform OPCAB in more than 90% of the patients, and that of the second stage was to proceed toward total arterial revascularization. The patients were grouped into four periods (102 patients for each period). Comparisons were performed with analysis of variance test and chi-square test where appropriate.

RESULTS

For periods 1 to 4, the number of OPCAB procedures was 65/102 (64%), 82/102 (80%), 97/102 (95%), and 99/102 (97%), respectively (p < 0.001). The number of conversions did not vary significantly throughout the study (overall: 7/408, 1.7%), neither did the number of bypass/patient (overall: 3.05 +/- 0.86). The number of arterial graft/patient was 1.03 +/- 0.64, 1.01 +/- 0.4, 1.29 +/- 0.64, and 2.56 +/- 1, respectively (p < 0.001). During the last period, 81% (253/312) of the grafts were arterial. Overall mortality was 4.6% (19/408). For the OPCAB group, mortality was 2.9% (10/343) and perioperative myocardial infarction rate was 1.5% (5/343) with no statistically significant difference between the periods.

CONCLUSIONS

With predefined standardized and coordinated protocols, an OPCAB program aimed at total arterial revascularization can be implemented rapidly and safely in a multidisciplinary setting.

Revascularization with off-pump coronary artery surgery: what appears new is actually the old rediscovered

The enormous progress in interventional cardiology during the last 10 years has resulted in a major change in the spectrum of patients referred for coronary artery bypass grafting. Several large retrospective analyses, meta-analyses, and the randomized trials that addressed different aspects of ONCAB and OPCAB to date have compared the two surgical strategies. It is suggested that patients may achieve an excellent outcome with either type of procedure, and individuals' outcomes more likely depend on factors other than whether they underwent ONCAB or OPCAB. Nevertheless, there appear to be trends in most studies. These trends include less blood loss and need for transfusion, less myocardial enzyme release up to 24 h, less early neurocognitive dysfunction, and less renal insufficiency after OPCAB and propensity to lower costs, thereafter proving OPCAB to be safe and clinically effective. Here, we review the physiological advantages and clinical outcomes of OPCAB for myocardial revascularization and examine whether either strategy is superior and in which patients.

Living with off-pump coronary artery surgery: evolution, development, and clinical potential for coronary heart disease patients

The enormous progress in interventional cardiology during the last 10 years has resulted in a major change in the spectrum of patients referred for coronary bypass surgery. These patients are older and sicker and frequently have had previous percutaneous coronary interventions. Consequently, cardiac surgery is responding by adding new surgical techniques: off-pump open-chest coronary bypass surgery (OPCAB), minithoracotomy bypass surgery, videothoracoscopic (robotic) procedures, etc. Several registries published to date have proved OPCAB to be safe and clinically effective. Randomized studies and meta-analysis research in this field provide scientific support and suggest that myocardial, renal, and neurological functions, amongst others, are better preserved by OPCAB than by classic techniques that use a cardiopulmonary bypass pump (CPB). Moreover, avoidance of CPB yields significantly reduced oxidative stress and systemic inflammatory response. This results in higher safety for ischemic heart disease patients undergoing revascularization, thus offsetting the propensity to lower costs. The present review examines the physiological advantages and clinical outcomes of this simple mode of myocardial revascularisation and evaluates the wider implications arising from its evolution.

Health-Related Quality of Life Outcome After On-Pump Versus Off-Pump Coronary Artery Bypass Graft Surgery: A Prospective Randomized Study

BACKGROUND

The clinical benefit of off-pump coronary artery bypass graft surgery over on-pump surgery is a matter of controversy. The aim of this study was to assess quality of life in patients after on-pump and off-pump coronary artery bypass graft surgery, and compare the data with an age-matched and sex-matched standard population.

METHODS

Two hundred twelve patients admitted for elective coronary artery bypass graft surgery were randomized to on-pump (n = 104) and off-pump (n = 108) surgery. Quality-of-life assessments were made 6 and 18 months postoperatively using the standard form of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36, version 2). The questionnaire yields eight subscores of functional health and well being. The eight SF-36 raw scores were standardized using means and standard deviations from a random sample of adults in Great Britain. Mean on-pump and off-pump SF-36 scores were compared using two-sample Student's t tests.

RESULTS

Questionnaires were completed for 72% (154 of 212) and 46% (98 of 212) of patients at the 6- and 18-month follow-up, respectively. There were no significant differences between on-pump and off-pump patients in any of the eight subscales at both stages. Fifty-six (72%) on-pump and 59 (75%) off-pump patients reported a better health status compared with the 6-month period before surgery (not significant).

CONCLUSIONS

Patients who have undergone off-pump coronary artery bypass graft surgery have a similar quality of life to on-pump patients at 6 and 18 months after surgery. For both groups, the majority of patients reported improved health after coronary artery bypass graft surgery compared with their preoperative status.

Resource utilization in on- and off-pump coronary artery surgery: Factors influencing postoperative length of stay—an experience of 1,746 consecutive patients undergoing fast-track cardiac anesthesia

OBJECTIVE

The purpose of the present investigation was to examine factors influencing resource utilization in patients undergoing on-pump coronary artery bypass graft and off-pump coronary artery bypass (OPCAB) graft surgery at a major university hospital. The resources examined were time to extubation, packed red blood cell (PRBC) transfusion, intensive care length of stay (ICULOS), preoperative and postoperative length of stay (PLOS), and total length of stay (LOS).

DESIGN

Observational study of consecutive patients undergoing on- and off-pump coronary artery bypass surgery.

SETTING

Tertiary care cardiac referral center.

PARTICIPANTS

One thousand seven hundred forty-six consecutive male and female patients undergoing primary coronary artery bypass graft (CABG) surgery over a period of 3 years (1999-2001). Eight hundred eighty-one patients underwent CABG with pump, and 865 patients underwent off-pump coronary artery bypass (OPCAB) surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean time to extubation after surgery was 7.4 hours for on-pump patients and 5.8 hours for the OPCAB group (p<or=0.001); 73.7% of patients on pump received PRBC transfusion as compared with 48.6% of the OPCAB group (p<or=0.001). The mean ICULOS for the on-pump group was 1.6 days and 1.4 days for the OPCAB group (p=0.006). PLOS was 6.5 days for the on-pump group and 5.6 days for the OPCAB group (p<or=0.001). Mean total LOS was 9.7 days for the on-pump group and 8.8 days for the OPCAB group (p<or=0.001). PLOS is correlated with several clinical and demographic ariables. Linear and logistic regression models were used to assess the effects of on/off pump on PLOS. Use of pump is significantly correlated with increased PLOS (p<or=0.001, Kendalls correlation), and pump use is strongly associated with transfusion (odds ratio=2.95, p<or=0.001), which in turn is a determinant of PLOS. There were no significant differences between the on- and off-pump groups in the incidence of postoperative complications except for bleeding requiring reexploration and ventilatory support for more than 72 hours. Incidence of bleeding was 3.3% in the on-pump group and 1.7% in the OPCAB group (p=0.038). In the on-pump group, 3% of patients required >72 hours to postoperative tracheal extubation compared with 1.5% in the OPCAB group (p=0.041). Hospital mortality was 2.7% for the on-pump group and 1.0% for the OPCAB group (p=0.010).

CONCLUSION

The authors found that patients undergoing on-pump CABG have significantly longer time to tracheal extubation, increased blood use, longer ICULOS, PLOS, and total LOS and higher in-hospital mortality, which would translate into significant differences in the expenses associated with these 2 surgical approaches to coronary surgery.

Monitoring the performance of residents during training in off-pump coronary surgery

OBJECTIVE

Control charts (eg, cumulative sum charts) plot changes in performance with time and can alert a surgeon to suboptimal performance. They were used to compare performance of off-pump coronary artery bypass surgery between a consultant and four resident surgeons and to compare performance of off-pump coronary artery bypass surgery and conventional coronary artery bypass grafting within surgeons.

METHODS

Data were analyzed for consecutive patients undergoing coronary artery bypass grafting who were operated on by one consultant or one of four residents. Conversions were analyzed by intention to treat. Perioperative death or one or more of 10 adverse events constituted failure. Predicted risks of failure for individual patients were derived from the study population. Variable life-adjusted displays and risk-adjusted sequential probability ratio test charts were plotted.

RESULTS

Data for 1372 patients were analyzed; 769 of the procedures were off-pump coronary artery bypass operations (56.0%). The consultant operated on 382 patients (293 off-pump, 76.7%), and the residents operated on 990 (474 off-pump, 47.9%). Patients operated on by residents tended to be older, more obese, more likely to require an urgent operation, and more likely to need a circumflex artery graft but less likely to have triple-vessel disease. There were 7 conversions (consultant 5, residents 2). The overall failure rate was 8.5% (9.2% for consultant's operations and 8.2% for residents' operations), including 10 deaths (0.7%). Predicted and observed risks of failure were similar for all five surgeons. After 100 off-pump coronary artery bypass operations, performance was the same or better for the residents as for the consultant. For all surgeons, performance was the same or better for off-pump as for conventional coronary artery bypass grafting.

CONCLUSIONS

Off-pump coronary artery bypass surgery can be safely taught to cardiothoracic residents. Implementation of continuous performance monitoring for residents is practicable.

Inflammatory response to cardiac surgery: cardiopulmonary bypass versus non-cardiopulmonary bypass surgery

Cardiac surgery has been routinely performed using cardiopulmonary bypass (CPB) ever since its clinical introduction during the 1950s. CPB is, however, associated with an intense inflammatory response because of conversion to laminar flow, blood contact with the artificial bypass surface, cold cardiac ischaemia and hypothermia. The inflammatory reaction can intensify to a systemic inflammatory response syndrome (SIRS) associated with serious morbidity and mortality. Strategies to suppress inflammation had some success but fell short of controlling SIRS. The development of cardiac immobilization techniques allowing complete revascularization has caused a renaissance of coronary artery bypass grafting surgery on the beating heart (OPCAB). This strategy avoids all inflammation caused by CPB and reduces the pro-inflammatory stimulus to sternotomy and the revascularization procedure itself. This review summarises the pathophysiological features of the inflammatory response to CPB, revisits therapeutic anti-inflammatory strategies designed to suppress CPB-induced inflammation and balances the clinical evidence available comparing off-pump and on-pump revascularization.

Trainees operating on high-risk patients without cardiopulmonary bypass: a high-risk strategy?

BACKGROUND

The safety of teaching off-pump coronary artery bypass grafting to trainees is best tested in high-risk patients, who are more likely to experience significant morbidity after surgery. This study compared outcomes of off-pump coronary artery bypass grafting operations performed by consultants and trainees in high-risk patients.

METHODS

Data for consecutive patients undergoing off-pump coronary artery bypass grafting were collected prospectively. Patients satisfying at least one of the following criteria were classified as high-risk: age older than 75 years, ejection fraction less than 0.30, myocardial infarction in the previous month, current congestive heart failure, previous cerebrovascular accident, creatinine greater than 150 micromol/L, respiratory impairment, peripheral vascular disease, previous cardiac surgery, and left main stem stenosis greater than 50%. Early morbidity, 30-day mortality, and late survival were compared.

RESULTS

From April 1996 to December 2002, 686 high-risk patients underwent off-pump coronary artery bypass grafting revascularization. Operations by five consultants (416; 61%) and four trainees (239; 35%) were the focus of subsequent analyses. Nine visiting or research fellows performed the other 31 operations. Prognostic factors were more favorable in trainee-led operations. On average, consultants and trainees grafted the same number of vessels. There were 18 (4.3%) and 5 (1.9%) deaths within 30 days, and 14 (3.4%) and 5 (1.9%) myocardial infarctions in consultant and trainee groups, respectively. After adjusting for imbalances in prognostic factors, odd ratios for almost all adverse outcomes implied no increased risk with trainee operators, although patients operated on by trainees had longer postoperative stays and were more likely to have a red blood cell transfusion. Kaplan-Meier cumulative mortality estimates at 24-month follow-up were 10.5% (95% confidence interval, 7.7% to 14.2%) and 6.4% (95% confidence interval, 3.8% to 10.9%) in consultant and trainee groups, respectively (hazard ratio = 0.60 [95% confidence interval, 0.37 to 0.99]; p = 0.05).

CONCLUSIONS

Off-pump coronary artery bypass grafting surgery in high-risk patients can be safely performed by trainees.

Off-pump versus on-pump coronary surgery: final results from a prospective randomized study PRAGUE-4

BACKGROUND

Off-pump coronary artery bypass surgery is becoming increasingly popular despite the lack of sufficient evidence from randomized trials. The aim of our prospective, randomized, single-center study was to examine the role of off-pump revascularization among nonselected patients.

METHODS

A total of 400 consecutive nonselected patients (mean age 63 years) scheduled for isolated coronary revascularization were randomized by a cardiologist into two groups: A (on-pump) and B (off-pump). The cardiac surgeon was allowed to change the operative technique at any time after randomization. The only exclusion criterion was an emergency procedure. The primary end point was any of the following within 30 days: death, myocardial infarction, stroke, or new renal failure requiring hemodialysis. The study was analyzed on the intention-to-treat principle.

RESULTS

The primary end point occurred in 4.9% of patients in group A versus 2.9% in group B (not significant). Mortality was 1.1% in group A versus 2.0% in group B (not significant). Preoperative crossover occurred in 5.4% of patients in each group (not significant). Intraoperative conversion was necessary in 9.8% of patients in group B versus 1.1% of patients in group A (p < 0.001). Group B patients had fewer distal anastomoses (2.3 versus 2.7 in group A; p < 0.001), less blood loss (560 versus 680 mL; p < 0.001), lower postoperative creatine kinase MB levels (0.15 versus 0.56 microkat/L; p < 0.001) and lower total hospital costs (3,451 versus 4,387; p < 0.001).

CONCLUSIONS

In our study off-pump technique was applicable in 85% of nonselected patients and is at least as clinically safe and effective as on-pump surgery.

Off-pump complete revascularization through a left lateral thoracotomy (ThoraCAB): the first 200 cases

BACKGROUND

Conventional coronary bypass surgery is associated with substantial morbidity caused by cardiopulmonary bypass (CPB) and median sternotomy. This report describes an innovative technique to perform complete revascularization through a lateral thoracotomy without CPB (thoraCAB).

METHODS

From February 2000 to April 2001 a total of 200 patients underwent thoraCAB. The patient is positioned with the left side elevated to 45 degrees. A 5- to 6-inch incision is made over the left fourth or fifth intercostal space from just medial to the nipple to the anterior axillary line. The left internal thoracic artery is harvested as a pedicle graft under vision. Proximal anastomoses are first completed on the ascending aorta, followed by the distal coronary anastomoses on the beating heart using a stabilizer. Intercostal nerve freezing is done using a cryoprobe.

RESULTS

Complete revascularization was achieved in all patients. The number of grafts averaged 2.9 +/- 1.08 per patient. One patient (0.5%) died of renal failure. Two patients (1%) were converted to CPB. No strokes were observed. Three patients (1.5%) required prolonged ventilation (>48 hours). Five patients (2.5%) had postoperative bleeding requiring reexploration. Of the patients, 16 (8%) developed new-onset postoperative atrial fibrillation.

CONCLUSIONS

ThoraCAB has been feasible in the vast majority of patients requiring coronary bypass surgery. The prevalence of postoperative atrial fibrillation was low. Postoperative pain maybe lessened with intercostal nerve freezing.

The evolution of training in off-pump coronary surgery in a single institution

BACKGROUND

This study analyses the development of off-pump coronary artery bypass (OPCAB) surgery training at a single institution, and compares the early and midterm clinical outcomes of OPCAB and conventional coronary artery bypass grafting (CABG) procedures performed by trainees with or without direct consultant cardiothoracic surgeon supervision.

METHODS

Analysis was undertaken on data prospectively recorded on a computer database (Patient Analysis and Tracking System). Of the 2,422 CABG operations performed between January 1999 and December 2001, 969 (40%) were carried out by trainees either off pump (422) or on pump (547).

RESULTS

Although the total number of CABG operations performed by trainees remained constant, there was a significant increase in the number of OPCAB operations during the study period compared with conventional CABG, as well as an increase in the average number of grafts per patient in the OPCAB group (both p < 0.05). Furthermore, a significant trend towards using two or more arterial conduits in the OPCAB group was observed in the study period. The number of OPCAB operations performed by trainees as independent operators without direct consultant supervision also increased significantly (p < 0.05). Early and midterm clinical outcomes were similar between patients operated by trainees on pump or off pump as independent operators versus under direct consultant supervision.

CONCLUSIONS

The significant increase in OPCAB operations performed by trainees as independent operators or under direct consultant supervision, as well as the increase in the number of grafts per patient and arterial conduits used for myocardial revascularization, demonstrate a progression of training in beating heart surgery for cardiothoracic trainees. Improvements in the techniques have made it safe to teach trainees off-pump multivessel coronary artery revascularization.

Improved outcomes in coronary artery bypass grafting with beating-heart techniques

OBJECTIVE

Although improved outcomes for selected patients by elimination of cardiopulmonary bypass have been demonstrated, a benefit for all patients undergoing coronary artery bypass grafting by all surgeons has yet to be definitively proved.

METHODS

We reviewed our experience with beating-heart surgery from its inception in January 1995 through December 2000. A total of 12,540 patients underwent isolated coronary artery bypass grafting, including 1915 procedures (15%) performed without cardiopulmonary bypass. Groups were compared by univariate analysis for preoperative risk factors and postoperative complications, and predicted risk was determined by the Society of Thoracic Surgeons risk algorithm.

RESULTS

There was a gradual increase in the percentage of coronary operations performed off pump, from 1.2% in 1995 to 34.1% in 2000. Individual surgeon adoption rates ranged from 1% to 96% by 2000. There was a decrease in mortality to 3.22%, compared with an overall observed mortality rate of 4.0% in the 5 years before beating-heart surgery (P =.0482). There was a significant difference in observed mortality between the off-pump and on-pump groups (1.9% vs 3.5%, P <.001), despite a higher mean predicted risk among the patients in the off-pump group (3.13% vs 2.8%, P <.004). Additionally, decreased morbidity in the off-pump group was evidenced by reduced needs for blood products (28.45% vs 54.65%, P =.0001), prolonged ventilation (5.83% vs 10.93%, P =.001), and reoperation for bleeding (2.41% vs 3.65%, P =.0237), and by shorter hospital stay (5.98 vs 7.32 days, P =.001).

CONCLUSIONS

Beating-heart surgery can be safely assimilated into a cardiac surgical practice, although adoption rates vary significantly among individual surgeons. Gradual integration can lead to improved outcomes in the total coronary artery bypass surgery population.

Off-pump coronary revascularization: is it all that it's cracked up to be?

There has been a recent resurgence in the use of off-pump coronary artery surgery. This article provides the critical care nurse with information about the procedure.

Initial prospective multicenter clinical trial of robotically-assisted coronary artery bypass grafting

BACKGROUND

This multicenter prospective trial was designed to assess the safety and efficacy of using a robotically-assisted microsurgical system to create endoscopic coronary anastomoses.

METHODS

. Thirty-two patients scheduled for elective primary coronary surgery underwent endoscopic anastomosis of the left internal thoracic artery (LITA) to the left anterior descending (LAD) artery. Three thoracic ports (two for instruments and one for a camera) were placed, and a robotic system was used to perform the LITA-LAD graft. Conventional techniques were used to perform the other grafts. Thirty-one patients underwent median sternotomy and 1 patient underwent a limited anterior thoracotomy.

RESULTS

. Graft flow was measured in the operating room and averaged 37 +/- 19 mL/min. Mean anastomosis time was 24 +/- 9 minutes. There were three intraoperative revisions (9%). Two were for inadequate flow and one for an inadvertent injury. Each of these grafts was successfully revised by hand. There were no technical failures of the robotic system. Average postoperative length of stay was 5.5 +/- 2.7 days. There were three reoperations for bleeding, but none of these were related to the LAD anastomosis. Two months following the operation, selective angiography revealed a graft patency of 93%. The patients have been followed for 16 +/- 4 months.

CONCLUSIONS

This initial prospective multicenter trial documents the feasibility of robotically-assisted coronary bypass grafting. Further trials are warranted to establish the safety and efficacy of this new technology.

Cumulative sum failure analysis of a policy change from on-pump to off-pump coronary artery bypass grafting

BACKGROUND

Use of the sequential probability cumulative sum (CUSUM) technique may be more sensitive than standard statistical analyses in detecting a cluster of surgical failures. We applied CUSUM methods to evaluate the learning curve after a policy change by a single surgeon from routine on-pump (cardiopulmonary bypass [CPB]) to off-pump coronary artery bypass grafting (OPCAB).

METHODS

Fifty-five consecutive first-time coronary artery bypass patients (CPB group) were compared with the next 55 patients undergoing an attempt at routine OPCAB using the same coronary stabilizer. The goal in OPCAB patients was to obtain complete revascularization, albeit with a low threshold for conversion to CPB to maximize patient safety during the learning curve. Preoperative patient risk was calculated using previously validated models of the Cardiac Care Network of Ontario. The occurrence of operative mortality and nine predefined major complications (myocardial infarction, bleeding, stroke, renal failure, balloon pump use, mediastinitis, respiratory failure, life-threatening arrhythmia, and sepsis) was compared between the CPB and OPCAB groups using Wilcoxon, Fisher exact, and two-tailed t tests, as well as CUSUM methodology. An intention to treat analysis was performed.

RESULTS

The CPB and OPCAB groups had similar predicted mortality and length of stays (2.2% +/- 2.5%, 8.1 +/- 2.5 days versus 2.4% +/- 3.5%, 8.1 +/- 2.4 days, respectively). The mean number of grafts per patient was 3.1 +/- 0.7 in the CPB group versus 3.0 +/- 0.7 in the OPCAB group (p = 0.45). Two of 55 (3.6%) CPB patients died, as opposed to 1 of 55 (1.8%) OPCAB patients (p = 0.99). Eight of 55 CPB patients (14.5%) incurred major complications, as opposed to 4 of 55 (7.3%) OPCAB patients (p = 0.36). Median hospital length of stay was 6.0 days in the CPB group versus 5.0 days in the OPCAB group (p = 0.28). On CUSUM analysis, the failure curve in CPB patients approached the upper 80% alert line after eight cases, whereas the curve in OPCAB patients reached below the lower 80% (reassurance) boundary 28 cases after the policy change, indicating superior results in the OPCAB group despite the learning curve.

CONCLUSIONS

A policy change from coronary artery bypass on CPB to routinely attempting OPCAB can be accomplished safely despite the learning curve. CUSUM analysis was more sensitive than standard statistical methods in detecting a cluster of surgical failures and successes.

Beating heart surgery or conventional CABG: are neurologic outcomes different?

Although there has been much debate about the causes of neurologic complications associated with coronary artery bypass grafting (CABG), there is good evidence linking such complications with some of the pathophysiologic changes associated with use of conventional cardiopulmonary bypass (CPB). Several studies indicate that it is possible to significantly lower risk of stroke and other central nervous system (CNS) morbidity in patients undergoing CPB for CABG by application of selected techniques and equipment modifications. The resurgence of interest in coronary revascularization by using beating heart surgery (BHS) offers a unique opportunity to evaluate neurologic outcome independent of CPB. Currently, BHS would appear to significantly reduce morbidity in the elderly and to decrease the costs and resource use in coronary revascularization patients. It is hoped that by understanding the mechanisms of CNS injury associated with CABG, techniques can be developed to decrease the risk of neurologic injury associated with coronary revascularization, whether or not CPB is used. Definitive conclusions regarding outcomes after best practice CPB or BHS await large-scale, risk-stratisfied multicenter trials.