Direct myocardial revascularization without extracorporeal circulation. Experience in 700 patients

Coronary hybrid revascularization from January 1997 to January 2001: a clinical follow-up

BACKGROUND

Hybrid revascularization (HyR), combining minimally invasive left internal mammary artery (LIMA) bypass grafting to the left anterior descending coronary artery (LAD) and catheter interventional treatment of the remaining coronary lesions, avoids the disadvantages associated with cardiopulmonary bypass (CPB). We investigated the clinical follow-up of 57 patients with multivessel disease undergoing this procedure in the last 4 years.

METHODS

Between January 1997 and January 2001, 57 consecutive patients (41 men and 16 women, aged 65.7 +/- 7.9 years) with coronary artery disease (two-vessel, n = 34; three-vessel, n = 23) were treated with off-pump LIMA-to-LAD bypass combined with balloon angioplasty and stenting of the remaining significantly obstructed (> 50%) coronary vessels. Clinical follow-up data included a early postoperative and a 6-month control angiography and a patient interview in January 2001.

RESULTS

All patients underwent LIMA-to-LAD bypass-grafting and balloon angioplasty in 72 coronary lesions without procedural-related complications. However, one early LIMA bypass occlusion was documented during coronary angiography. Postoperatively no deterioration of preexistent organ dysfunction was observed in any patient. The mean follow-up was 100.7 +/- 37.9 weeks in 55 of 57 patients (97%). Control angiography 6 months after HyR (n = 34) revealed a patent LIMA bypass in 33 patients and 8 in-stent restenoses (> 50%) in the coronary arteries that were treated interventionally by re-PTCA (n = 6) or by conventional CABG (n = 1). In 1 patient medical treatment resulted in significant reduction of angina so no further intervention was considered necessary. After HyR 1 patient died 18 months later of an intracerebral hemorrhage. All other patients are alive and doing well.

CONCLUSIONS

Our results indicate that in selected patients with multivessel disease including left main stem stenosis HyR is an effective and secure procedure with excellent early and good midterm results. Especially elderly patients with severe concomitant diseases appear to benefit from this approach by avoiding CPB.

Occlusion versus shunting during MIDCAB: effects on left ventricular function and quality of anastomosis

BACKGROUND

Minimally invasive direct coronary artery bypass is an established clinical procedure for revascularization of the left anterior descending coronary artery. Mechanical stabilization and temporary occlusion is currently used to perform the anastomosis of the internal thoracic artery to the left anterior descending coronary artery. However, critical reduction of cardiac function can occur as a result of temporary ischemia. The purpose of this study was to evaluate whether ischemic sequelae can be avoided by using temporary intraluminal shunts and whether this alters early outcome.

METHODS

Thirty-five patients underwent minimally invasive direct coronary artery bypass revascularization using a mechanical stabilizer. In group A (n = 20), the anastomotic site was temporarily occluded by tourniquets. In group B (n = 15), temporary intraluminal shunts were inserted into the anastomotic site without any occlusion of the left anterior descending coronary artery. Anastomosis of the internal thoracic artery to the left anterior descending coronary artery was performed in an identical fashion. A Swan-Ganz catheter was inserted, and transesophageal echocardiographic measurements were obtained for analysis of left ventricular (LV) function. Regional wall motion, cardiac index, stroke volume index, systolic and diastolic LV diameters, and fractional area change were measured during four periods: at the start of the operation (baseline), placement of the stabilizer (stabilization), left anterior descending coronary artery occlusion (occlusion) or insertion of temporary intraluminal shunts (shunt), and 30 minutes after reperfusion (reperfusion). Angiograms were obtained 4 to 6 days postoperatively.

RESULTS

In group A, LV performance, cardiac index, stroke volume index, and fractional area change decreased during occlusion whereas systolic diameters increased. Almost two myocardial segments per patient developed severe hypokinesia in the perfusion area. These changes disappeared after 30 minutes of reperfusion, with increased LV function. In group B, LV function remained stable whereas hypokinetic wall motion was only detected in 2 patients. Early angiograms revealed 90% of the grafts were patent in group A versus 100% in group B. The need for percutaneous intervention during the first 6 months was 20% in group A versus 6.7% in group B.

CONCLUSIONS

The use of temporary intraluminal shunts resulted in reduced acute ischemia and revealed wall motion abnormalities and maintained LV function. Furthermore, this technique suggests an improvement of early graft patency and a lower reintervention rate within the first 6 postoperative months. Thus, use of temporary intraluminal shunts appears to be superior to the occlusion technique early after minimally invasive direct coronary artery bypass procedures.

Elimination of cardiopulmonary bypass improves early survival for multivessel coronary artery bypass patients

BACKGROUND

Coronary artery bypass graft (CABG) surgery performed without cardiopulmonary bypass (CPB) is currently increasing in clinical practice. Decreased morbidity associated with off-pump (OP) CABG in selected risk groups examined in relatively small, single institution groups has been the focus of most recent studies. The purpose of this study was to determine the independent impact of CPB on early survival in all isolated multivessel CABG patients undergoing surgery in two large institutions with established experience in OPCABG techniques.

METHODS

A review of two large databases employed by multiple surgeons in the hospitals of two institutions identified 8,758 multivessel CABG procedures performed from January 1998 through July 2000. In all, 8,449 procedures were included in a multivariate logistic regression analysis to determine the relative impact of CPB on mortality independent of known risk factors for mortality. Procedures were also divided into two treatment groups based on the use of CPB: 6,466 had CABG with CPB (CABG-CPB), 1,983 had CABG without CPB (OPCABG). Disparities between groups were identified by univariate analysis of 17 preoperative risk factors and treatment groups were compared by Parsonnet's risk stratification model. Finally, computer-matched groups based on propensity score for institution selection for OPCABG were combined and analyzed by a logistic regression model predicting risk for mortality.

RESULTS

CABG-CPB was associated with increased mortality compared with OPCABG by univariate analysis, 3.5% versus 1.8%, despite a lower predicted risk in the CABG-CPB group. CPB was associated with increased mortality by multiple logistic regression analysis with an odds ratio of 1.79 (95% confidence interval = 1.24 to 2.67). An increased risk of mortality associated with CPB was also determined by logistic regression analysis of the combined computer-matched groups based on OPCABG-selection propensity scores with an odds ratio of 1.9 (95% confidence interval = 1.2 to 3.1).

CONCLUSIONS

Elimination of CPB improves early survival in multivessel CABG patients. Rigorous attempts to statistically account for selection bias maintained a clear association between CPB and increased mortality. Larger multiinstitutional studies are needed to confirm these findings and determine the most appropriate application of OPCABG.

The early clinical and angiographic outcome of sequential coronary artery bypass grafting with the off-pump technique

OBJECTIVE

The emergence of the off-pump coronary artery bypass technique has made surgeons consider combining it with other techniques developed and learned with conventional coronary artery bypass grafting with cardiopulmonary bypass. One of these techniques is the construction of a sequential graft to bypass more than one coronary vessel. The purpose of this study is to review the outcome of combining sequential coronary artery bypass grafting with off-pump techniques.

METHODS

We retrospectively reviewed the records of 45 consecutive patients who underwent isolated coronary bypass surgery with off-pump and sequential grafting techniques at Harefield Hospital (Harefield, UK) between July 1999 and December 2000. The registry database, medical notes and charts were studied for preoperative and postoperative data of the patients. Ten patients consented and underwent early postoperative angiography to check the quality of the grafts and anastomoses.

RESULTS

There were no deaths among the study patients. Morbidity consisted of atrial fibrillation in 6 patients (13.3%), leg wound infection in 2 patients (4.4%), and pleural effusion in 1 patient (2.2%). Early angiography of the 10 consenting patients revealed 10 patent sequential grafts (100%) with 20 satisfactory end-to-side and side-to-side anastomoses (100%).

CONCLUSION

The combination of sequential grafting and off-pump techniques is feasible, is safe, and provides good early clinical and angiographic outcomes.

Conversion to off-pump coronary bypass without increased morbidity or change in practice

BACKGROUND

This article examines the feasibility of complete conversion from conventional coronary artery operation to routine off-pump coronary bypass operation.

METHODS

Data on our first 285 off-pump procedures using the Octopus system (Medtronic Inc, Minneapolis, MN) represent our learning curve. This is a complete experience in coronary bypass surgery over 16 months.

RESULTS

The cohort was nonselected. All patients had at least two-vessel disease. Eight hundred seven grafts were performed (mean, 2.8 per patient) of which 647 grafts (84%) were arterial (mean, 2.3 per patient). One hundred seventy nine patients (63%) underwent total arterial revascularization. Eight patients required cardiopulmonary bypass; all other operations were completed off-pump. Complications were: mortality, 3 patients (1.5%); renal failure, 24 patients (8%); stroke, 2 patients (< 1%); and atrial fibrillation, 60 patients (21%). The morbidity data and frequency of arterial grafting did not differ from that of 355 patients who underwent coronary bypass operations in a preceding 18-month period.

CONCLUSIONS

Complete shift from routine use of cardiopulmonary bypass to nonselective off-pump coronary bypass operation is possible with a low conversion rate and without an apparent increase in morbidity or change in technique. Whereas short-term safety and efficacy seem certain, studies of long-term outcome are necessary before the eventual role of off-pump coronary bypass in myocardial revascularization can be defined.

To ventilate or not after minimally invasive direct coronary artery bypass surgery: the role of epidural anesthesia

OBJECTIVE

To evaluate the effect of immediate postoperative extubation and postoperative ventilation after minimally invasive direct coronary artery bypass (MIDCAB) surgery and to assess the role of epidural anesthesia.

DESIGN

Randomized prospective study.

SETTING

University hospital, single institution.

PARTICIPANTS

Patients (n = 90) scheduled for elective MIDCAB surgery.

INTERVENTIONS

Patients were divided into 3 groups: 30 patients had general anesthesia and were extubated immediately after surgery (extubated group), 30 patients had a thoracic epidural and general anesthesia and were extubated immediately after surgery (epidural group), and 30 patients had general anesthesia and were ventilated after surgery (intubated group).

MEASUREMENTS AND MAIN RESULTS

With a similar cardiac index and less vasoactive medication, mean arterial blood pressure (77 plus minus 8 mmHg [mean plus minus SD]) and heart rate (76 plus minus 10 beats/min) in the epidural group were lower on the first postoperative day than in the intubated group (83 plus minus 10 mmHg and 81 plus minus 13 beats/min) and the extubated group (86 plus minus 10 mmHg and 83 plus minus 13) (p = 0.01 and p = 0.09). Oxygenation on the first postoperative day was better in the epidural group than in the intubated group (14.8 plus minus 3.8 kPa v 12.6 plus minus 3.2 kPa; p = 0.05). The epidural group and the extubated group had a transient respiratory acidosis postoperatively. Pain score in the epidural group was lower on the first postoperative day than in the extubated group with general anesthesia (3.0 plus minus 1.6 visual analog scale v 4.6 plus minus 1.8 visual analog scale; p = 0.01). Hospital stay was shorter in the epidural group than in the ventilated group (5.9 plus minus 2.4 days v 8.1 plus minus 5.3 days; p = 0.05)

CONCLUSION

Immediate postoperative extubation in patients with thoracic epidural anesthesia and supplemental general anesthesia provides the most favorable clinical circumstances after MIDCAB surgery.

[Beating heart in "aortic no-touch off-pump" techniques: a simple answer to complex surgical situations]

Three cases reports illustrate the concept of beating heart cardiac surgery and its advantages regarding the prevention of arterial emboli.

Off-pump coronary revascularization: current state of the art

Patients presenting for surgical coronary artery bypass grafting (CABG) are older and have more comorbidity than patients in prior decades. Cardiopulmonary bypass (CPB) may add to the elevated morbidity and mortality seen in these higher-risk patients. After the re-introduction of single-vessel bypass without CPB, surgeons have developed techniques for multivessel off-pump coronary artery bypass (OPCAB) through sternotomy. Understanding the causes of the hemodynamic disturbances seen during cardiac displacement has led to surgical techniques that minimize mechanical compression and the effects of temporary regional ischemia. With careful attention to detail, OPCAB has been shown to be feasible in nearly all patients needing coronary artery bypass. The procedure has been demonstrated to be safe and effective. Early outcomes and graft patency rates appear to be at least as good as those seen with traditional CPB-supported CABG. Certain high-risk groups may be better treated with OPCAB, but further studies are necessary to elucidate which patients should be offered OPCAB and which should receive standard CABG.

Off-Pump Coronary Artery Bypass Surgery: Revival of an Old Technique

The ability to perform surgical procedures on the heart was one of the greatest accomplishments of the 20th century. What was once considered an impossible task has become a routine in daily clinical activity. The in troduction of extracorporeal circulation and myocardial protection strategies opened the doors to what was considered by most an insurmountable barrier— unhin dered access to the coronary circulation and intracar diac structures. In the United States, approximately 85% of coronary artery bypass graft procedures are performed with the use of cardiopulmonary bypass (CPB). CPB was and remains the gold standard for this type of cardiac surgical intervention. Over the years, investigators have struggled to find ways of lessening or eliminating the adverse physiologic effects of CPB. These efforts have focused on pharmacologic interven tion, monitoring procedures, blood gas management, and temperature management. Another way of avoid ing these effects is inherently obvious — eliminate the main source of the problem.

On-pump and off-pump coronary artery bypass grafting in the elderly: predictors of adverse outcome

OBJECTIVE

To establish the role that coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) may have in improving perioperative outcomes of patients 70 years of age and older.

BACKGROUND

Coronary revascularization in elderly patients is associated with morbidity and mortality rates higher than those observed in younger patients. The impact of CABG without CPB on perioperative outcomes has not been clearly established.

METHODS

This retrospective, nonrandomized study consisted of 1,872 CABG patients. Of these, 1389 underwent CABG with CPB (CPB group) and 483 patients underwent CABG without CPB (off-pump group). Preoperative variables and outcomes were compared between the two groups. Multivariate logistic regression analysis was used to identify independent predictors of mortality, stroke, and adverse outcome.

RESULTS

Demographics, Canadian Cardiovascular Society staging, operative priority, and other preoperative variables were comparable between the two groups. The prevalence of previous myocardial infarction was higher in the CPB group (62.6% vs 56.7%; p < 0.005), whereas the prevalence of calcified aorta and preoperative renal failure were higher in the off-pump group (5.4% vs 9.5%; p = 0.04 and 1.7% vs 3.3%; p = 0.04, respectively). Although the graft/patient ratio was higher in the CPB group (3.4 vs 1.9), these patients displayed more extensive coronary artery involvement. At univariate analysis, patients in the off-pump group had a higher rate of freedom from complications (88.2% vs 81.3%; p < 0.005) and a lower incidence of stroke (2.1% vs 4.2%; p = 0.034) than patients in the CPB group. Although there was a trend for a higher actual mortality in the off-pump group (4.8% vs 3.7%; p = ns), the risk adjusted mortality in this group was lower (1.9% vs 2.1%). Multivariate analysis showed that while the use of CPB correlated independently with an increased risk of overall complications, it was not associated with a higher probability of death or stroke.

CONCLUSIONS

This investigation suggests that elderly patients undergoing CABG may benefit from off-pump revascularization, as the use of CPB correlated independently with an increased risk of overall complications. However, CPB did not emerge as an independent predictor of death or stroke at multivariate analysis.

Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity

BACKGROUND

The purpose of this study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) decreases risk-adjusted operative death and major complications after coronary artery bypass grafting in selected patients.

METHODS

Using The Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database, procedural outcomes were compared for conventional and off-pump CABG procedures from January 1, 1998, through December 31, 1999. Mortality and major complications were examined, both as unadjusted rates and after adjusting for known base line patient risk factors.

RESULTS

A total of 126 experienced centers performed 118,140 total CABG procedures. The number of off-pump CABG cases was 11,717 cases (9.9% of total cases). The use of an off-pump procedure was associated with a decrease in risk-adjusted operative mortality from 2.9% with conventional CABG to 2.3% in the off-pump group (p < 0.001). The use of an off-pump procedure decreased the risk-adjusted major complication rate from 14.15% with conventional CABG to 10.62% in the off-pump group (p < 0.0001). Patients receiving off-pump procedures were less likely to die (adjusted odds ratio 0.81, 95% CI 0.70 to 0.91) and less likely to have major complications (adjusted odds ratio 0.77, 95% CI 0.72 to 0.82).

CONCLUSIONS

Off-pump CABG is associated with decreased mortality and morbidity after coronary artery bypass grafting. Off-pump CABG may prove superior to conventional CABG in appropriately selected patients.

Comparing clinical outcomes in high-volume and low-volume off-pump coronary bypass operation programs

sites and then analyzed the patient and hospital characteristics that had an impact on clinical outcomes.

RESULTS

The mortality rates for the high- and low-volume OPCAB facilities both averaged 2.9% (p = NS). Patients at the high-volume OPCAB facilities had significantly lower rates of major complications (shock/hemorrhage, neurologic, renal, and cardiac) than those at the low-volume OPCAB facilities. Of the seven minor complications, rates for six were lower in the high-volume OPCAB facilities, but none of the differences reached statistical significance. High-volume OPCAB sites were significantly more likely to discharge their patients directly home than were low-volume OPCAB sites (80% versus 66%; p = 0.001).

CONCLUSIONS

The results suggested that surgical team experience and choice of approaches to performing CABG had an impact on patient outcomes.

Tranexamic acid in off-pump coronary surgery: a preliminary, randomized, double-blind, placebo-controlled study

BACKGROUND

We evaluated the hemostatic effects of tranexamic acid, a synthetic antifibrinolytic drug, in patients undergoing beating-heart coronary surgery.

METHODS

Forty consecutive patients were in a double-blind manner, prospectively randomized into two groups: 20 patients received tranexamic acid (bolus of 1 g before skin incision, followed by continuous infusion of 400 mg/hr during surgery), and 20 patients received saline. As primary outcomes, bleeding and allogeneic transfusions were considered. D-dimer and fibrinogen plasma levels were also evaluated to monitor the activation of fibrinolysis. Major postoperative thrombotic events, as a potential consequence of antifibrinolytic treatment, were recorded.

RESULTS

The treatment group had significantly lower postoperative bleeding (median [25th to 75th percentiles]: 400 mL [337 to 490 mL] vs 650 ml [550 to 862 mL], p < 0.0001), lower need for allogeneic blood products (1,200 vs 5,300 mL, p < 0.001), and lower postoperative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group.

CONCLUSIONS

In this initial series of patients undergoing off-pump coronary surgery, tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Myocardial revascularization with and without cardiopulmonary bypass in multivessel disease: impact of the strategy on early outcome

BACKGROUND

The impact of myocardial revascularization without cardiopulmonary bypass (CPB) was evaluated in a series of consecutive patients with multivessel disease.

METHODS

From May 21, 1997 to November 30, 2000, 1,843 consecutive patients underwent isolated myocardial revascularization. From this total, 919 patients were done without CPB (group A, 49.9%) and 924 patients were done with CPB (group B, 50.1%). Patients that converted from without CPB to with CPB were included in group A. Thirty-three variables were evaluated with univariate and multivariate analysis to identify the independent variables predictive of higher incidence of early mortality, acute myocardial infarction, cerebrovascular accident, and early major events.

RESULTS

Early mortality was 2.2% (group A, 1.4%; group B, 3.0%; p = 0.016), acute myocardial infarction incidence was 1.8% (group A, 1.1%; group B, 2.6%; p = 0.027), cerebrovascular accident incidence was 0.9% (group A, 0.8%; group B, 1.0%; p = not significant), and early major events incidence was 6.7% (group A, 5.3%; group B, 8.2%; p < 0.001). Stepwise logistic regression analysis showed that CPB was an independent risk factor for higher mortality (odds ratio, 2.2; p = 0.0217), higher incidence of acute myocardial infarction (odds ratio, 2.5; p = 0.0185), and higher incidence of early major events (odds ratio, 1.8, p = 0.0034).

CONCLUSIONS

When CPB was not used, patients experienced lower early mortality and incidences of acute myocardial infarction were less complicated, both at univariate analysis and stepwise logistic regression analysis.

Off-pump coronary artery bypass is associated with improved risk-adjusted outcomes

BACKGROUND

The impact of off-pump median sternotomy coronary artery bypass grafting procedures on risk-adjusted mortality and morbidity was evaluated versus on-pump procedures.

METHODS

Using the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Program records from October 1997 through March 1999, nine centers were designated as having experience (with at least 8% coronary artery bypass grafting procedures performed off-pump). Using all other 34 Veterans Affairs cardiac surgery programs, baseline logistic regression models were built to predict risk of 30-day operative mortality and morbidity. These models were then used to predict outcomes for patients at the nine study centers. A final model evaluated the impact of the off-pump approach within these nine centers adjusting for preoperative risk.

RESULTS

Patients treated off-pump (n = 680) versus on-pump (n = 1,733) had lower complication rates (8.8% versus 14.0%) and lower mortality (2.7% versus 4.0%). Risk-adjusted morbidity and mortality were also improved for these patients (0.52 and 0.56 multivariable odds ratios for off-pump versus on-pump, respectively, p < 0.05).

CONCLUSIONS

An off-pump approach for coronary artery bypass grafting procedures is associated with lower risk-adjusted morbidity and mortality.

Clinical outcomes, angiographic patency, and resource utilization in 200 consecutive off-pump coronary bypass patients

BACKGROUND

This retrospective study compared clinical outcomes and resource utilization in patients having off-pump coronary artery bypass grafting (OPCAB) versus conventional coronary artery bypass grafting (CABG). Angiographic patency was documented in the OPCAB group.

METHODS

From April 1997 through November 1999, OPCAB was performed in 200 consecutive patients, and the results were compared with those in a contemporaneous matched control group of 1,000 patients undergoing CABG. Patients were matched according to age, sex, preexisting disease (renal failure, diabetes, pulmonary disease, stroke, hypertension, peripheral vascular disease, previous myocardial infarction, and primary or redo status. Follow-up in the OPCAB patients was 93% and averaged 13.4 months.

RESULTS

Hospital death (1.0%), postoperative stroke (1.5%), myocardial infarction (1.0%), and re-entry for bleeding (1.5%) occurred infrequently in the OPCAB group. There were reductions in the rates of transfusion (33.0% versus 70.0%; p < 0.001) and deep sternal wound infection (0% versus 2.2%; p = 0.067) in the OPCAB group compared with the CABG group. Angiographic assessment of 421 grafted arteries was performed in 167 OPCAB patients (83.5%) prior to hospital discharge. All but five were patent (98.8%) (93.3% FitzGibbon A, 5.5% FitzGibbon B, 1.2% FitzGibbon O). All 163 internal mammary artery grafts were patent. Off-pump coronary artery bypass grafting reduced postoperative hospital stay from 5.7 +/- 5.3 days in the CABG group to 3.9 +/- 2.6 days (p < 0.001), with a decrease in hospital cost of 15.0% (p < 0.001).

CONCLUSIONS

Off-pump coronary artery bypass grafting reduces hospital cost, postoperative length of stay, and morbidity compared with CABG on cardiopulmonary bypass. Off-pump coronary bypass grafting is safe, cost effective, and associated with excellent graft patency and clinical outcomes.

Single vessel revascularization with beating heart techniques -- minithoracotomy or sternotomy?

OBJECTIVE

The purpose of the study was to evaluate the best surgical approach in off-pump single vessel revascularization of the left anterior descending coronary artery (LAD).

METHODS

In 256 patients a single left internal mammary artery (LIMA) to LAD bypass was performed with beating heart techniques through a left anterior minithoracotomy (minimally invasive direct coronary artery bypass (MIDCAB), n=129) or a full sternotomy (off-pump coronary artery bypass (OPCAB), n=127).

RESULTS

In the OPCAB group, significantly more severe comorbidities (P=0.001) and redo-operations were noted (P<0.001). Conversion to sternotomy or CPB was necessary in five MIDCAB patients and one OPCAB patient. No cerebrovascular accident was seen in both groups. There was no hospital death in MIDCAB- and two deaths in OPCAB procedures (P=ns). There was a significant reduction in time of surgery (P=0.028) and coronary occlusion (P=0.009) in the OPCAB group. No differences in postoperative ventilation time, ICU stay and length of hospital stay were recorded between groups. Wound infections occurred in six MIDCAB patients (4.7%) and one OPCAB patient (0.8%). Early postoperative reoperation due to graft failure was necessary in three patients after MIDCAB and two patients after OPCAB (P=ns). Confirmed by angiography, the early graft patency rate was 96 and 98%, respectively (P=ns).

CONCLUSIONS

Both beating heart techniques showed good results with low hospital mortality, low early complications and comparable angiographic results. Nevertheless, MIDCAB is a challenging technique as demonstrated by the longer times of surgery and coronary occlusion with a tendency towards a higher risk of conversion and wound infection. Thus, this technique should only be performed in selected patients with favourable coronary anatomy. Through a sternotomy approach, single vessel revascularization can be performed safely off-pump even in high-risk patients.

Coronary revascularization without cardiopulmonary bypass in high-risk patients: a route to the future

Previous reports have demonstrated that reoperative coronary revascularization, advanced age, female sex, and impaired left ventricular dysfunction are independent predictors of operative mortality after coronary artery bypass grafting (CABG). CABG without cardiopulmonary bypass (off-pump CABG) has been proposed as a potential therapeutic alternative in these high-risk patient groups. Despite the substantial learning curve associated with off-pump CABG, early outcomes of off-pump CABG in high-risk patients are better than those associated with the conventional on-pump CABG approach. These results suggest that off-pump CABG is a safe alternative to on-pump CABG in high-risk patients. Randomized prospective studies are needed to validate the results of these initial retrospective reports and to demonstrate the long-term benefits of this approach.

Myocardial revascularization of the beating heart in high-risk patients

OBJECTIVE

Myocardial revascularization without cardiopulmonary bypass (CPB) has been proposed as an alternative technique in patients at high risk for conventional coronary artery bypass grafting (CABG). The purpose of this article is to evaluate the potential benefit of such an approach.

METHODS

We retrospectively evaluated the perioperative results of off-pump CABG (OPCAB) performed from January 1995 to December 1999. Patients were divided into three groups on the basis of their preoperative risk factors: age greater than 80 years, reoperative CABG, and left ventricular ejection fraction percentage (LVEF%) less than 40%. The three subgroups were compared with patients operated on-CPB (ONCAB) during the same period of time. A total of 172 octogenarians had ONCAB versus 97 OPCAB, 307 reoperations were ONCAB versus 274 OPCAB, and 514 patients with LVEF% less than 40% were operated ONCAB versus 220 OPCAB.

RESULTS

Preoperative comorbidities were homogeneously distributed in the OPCAB and ONCAB groups. More extensive coronary artery disease was found in the ONCAB groups. A trend for a lower number of perioperative complications was reported in the OPCAB groups. Freedom from overall complications was significantly higher (p < 0.005) in the OPCAB group. Actual mortality rates in the OPCAB and ONCAB groups were comparable (p = NS).

CONCLUSIONS

CABG can be performed safely without CPB in patients with a high preoperative risk profile. Freedom from perioperative complications is markedly higher when the OPCAB approach is utilized.

Off-pump bypass surgery--experience of 250 cases

From April 1996 to October 1998, 250 patients with a mean age of 63 years (31-86 years) underwent coronary artery bypass grafting using the off-pump technique. The prime reason for using this technique was the need to minimize the surgical trauma by avoiding extracorporeal circulation. Fifty-seven percent of the patients had 1-vessel disease, 39% had 2-vessel disease and 4% 3-vessel disease. Sternotomy was performed in 196 patients and an anterior mini-thoracotomy in 54 patients. The mean number of coronary anastomoses was 1.5. Perioperative mortality was 0.4%. The first consecutive 87 patients underwent an early postoperative coronary angiography (days 1-5) revealing a graft patency of 96.5%. Five out of the 7 patients with occluded grafts subsequently underwent another intervention (surgical revascularization in 4 patients and percutaneous transluminal coronary angioplasty in one); 1.2% developed transmural myocardial infarction and 2.8% were reoperated upon for bleeding. The mean time of ventilatory support was 2.5+/-0.5 h. The mean ICU time for all patients was 12 h (0-10 days). The mean in-hospital time was 7 days (2-30 days). Coronary artery bypass surgery without the use of extracorporeal circulation is a safe procedure that can be performed with limited need for intensive care resources. However, long-term results remain to be investigated.

Revascularization of severe hibernating myocardium in the beating heart: early hemodynamic and metabolic features

BACKGROUND

We investigated the effects of coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) in selected patients with severe hibernating myocardium.

METHODS

Twelve patients (EF = 25% +/- 0.7%) with reversible ventricular dysfunction (from 2.0 +/- 0.06 to 1.6 +/- 0.05 left ventricular score index by echodobutamine, p < 0.01) in the territory of the left anterior descending artery (LAD) have been studied. Revascularization was achieved by anastomosing the left internal mammary artery to the LAD. The ischemic time of LAD was 9.0 +/- 0.4 minutes.

RESULTS

Left ventricular function increased 6 hours and 48 hours after revascularization (left ventricular stroke work index from 32 +/- 1.8 to 42 +/- 1.5 and 40 +/- 0.6 gxm/m2, respectively: p = 0.0001). During the surgical procedure, the heart did not release lactate or creatine phosphokinase. There were no perioperative deaths or severe complications.

CONCLUSIONS

Early hemodynamic and metabolic features of CABG without CPB in patients with hibernating myocardium suggest that this procedure is safe and results in a significant improvement of cardiac function without affecting myocardial metabolism.

A simple method for heart stabilization during off-pump multi-vessel coronary artery bypass grafting: surgical technique and short term results

Minimally invasive cardiac surgery regroups several technical options including small incision, video-assisted surgery and beating heart surgery but mechanical stabilization for off-pump multi-vessel coronary artery bypass grafting (CABG), remains a problem. We developed a simple method of stabilization with a fenestrated polytetrafluroethylene patch. Four sutures were passed deeply into the myocardium surrounding the anastomotic site. The sutures were then passed through the patch. Gentle traction on tied sutures, allowed immobilization and exposure in the selected area. This method which was carried in 95 patients, provides good stabilization for performing off-pump multi-vessel CABG in all cardiac territories.

One-year clinical outcome after minimally invasive direct coronary artery bypass

BACKGROUND

Minimally invasive coronary artery bypass (MIDCAB) is a new surgical technique by which the left internal mammary artery is anastomosed under direct visualization to the left anterior descending artery without cardiopulmonary bypass.

METHODS AND RESULTS

We followed all 274 patients who underwent MIDCAB from the time it was introduced at a single center. In-hospital and 1-year clinical events were source-documented and adjudicated. The in-hospital major acute cardiac event rate was 2.2%; this included a 1.1% mortality rate. At 1 year, the respective rates were 7.8% and 2. 5%. When compared with the initial 100 procedures, the subsequent 174 procedures had shorter vessel occlusion times (10+/-5 versus 14+/-6 minutes; P:=0.009), times to extubation (6+/-3 versus 14+/-10 hours; P:<0.001), and lengths of hospital stay (2.1+/-1.9 versus 3. 2+/-3.1 days; P:=0.04). Cumulative 1-year adverse cardiac events were 11% in the initial 100 cases and 6% in the subsequent 174 cases (P:=0.17).

CONCLUSIONS

Excellent clinical results can be achieved with the MIDCAB technique. The clinical adverse event rate may decrease with accumulated experience.

Minimally invasive coronary artery bypass grafting for the left anterior descending coronary artery

OBJECTIVE

A single surgeon conducted One hundred and twelve patients underwent minimally invasive direct coronary artery bypass grafting for the left anterior descending coronary artery 112 patients at Yamato Seiwa Hospital from September 1996 until August 1999.

METHODS

All procedures were performed via left anterior short thoracotomy using a stabilizer during graft anastomosis.

RESULTS

No operative deaths occurred but 3 patients died while hospitalized due to noncardiac events. Graft occlusion was seen in 3 patients early postoperatively. Other angiography graft failure such as stenosis was seen in 11 patients. Occlusive lesions of other coronary arteries occurred in 77 patients (69%) and 53 patients underwent percutaneous transluminal coronary angioplasty the pre/postoperatively for those lesions.

CONCLUSIONS

These results suggest that minimally invasive direct coronary artery bypass grafting is seen by cardiologists as a reasonable form of revascularization in conditioned patients having left anterior descending artery lesion, and that minimally invasive direct coronary artery bypass grafting has a spectrum of candidates different from that of conventional surgical revascularization for the coronary artery.

The Octopus Study: rationale and design of two randomized trials on medical effectiveness, safety, and cost-effectiveness of bypass surgery on the beating heart

The Octopus Study consists of two multicenter randomized clinical trials in which coronary artery bypass grafting on the beating heart (off-pump CABG) using the Utrecht Octopus Method is compared to intracoronary stent implantation and conventional CABG. The primary endpoint in the comparison of off-pump CABG versus stent implantation (OctoStent Trial) is medical effectiveness (i.e., absence of reintervention and major adverse cardiac and cerebrovascular events at 1 year after treatment). The primary endpoint in the comparison of off-pump CABG versus conventional CABG (OctoPump Trial) is cerebral safety (i.e., absence of cognitive deficits and cerebrovascular events at 3 months after treatment). Secondary endpoints in both trials include presence and severity of angina, quality of life, exercise capacity, and cost-effectiveness. A total of 560 patients will be enrolled. A random sample of 210 patients will undergo repeat angiography at 1 year to assess angiographic restenosis rate and graft patency. Including 1-year follow-up, the study will last for 3 years. Control Clin Trials 2000;21:595-609

Off-pump coronary bypass operations significantly reduce S100 release: an indicator for less cerebral damage?

BACKGROUND

Cardiac operations using extracorporeal circulation bear a risk of cerebral complications. The aim of our study was to investigate if off-pump operations without heart-lung machines can reduce cerebral injury.

METHODS

S100, a protein specific for cerebral tissue, was used as a marker for cerebral impairment in 108 randomized patients undergoing coronary bypass operation: 67 patients (group A) were operated on with extracorporeal circulation and cardioplegic cardiac arrest, and 41 patients (group B) underwent off-pump beating heart revascularization. Both groups were similar regarding age, sex, ejection fraction, and number of anastomoses. S100 levels were measured from induction of anesthesia until 24 hours after the operation.

RESULTS

Data collection was 100% complete. There was no in-hospital death. Nonfatal myocardial infarctions occurred in 2 patients in group A, and 1 patient in group B required resternotomy for bleeding. There was no neurologic deficit in either group. S100 levels increased only slightly in the off-pump patients (group B), whereas in group A there was a sharp rise in S100 concentration during extracorporeal circulation, only returning to baseline 6 hours after the end of the operation. Peak S100 levels were four times higher in group A than in group B (2.1 microg/L versus 0.5 microg/L; p < 001).

CONCLUSIONS

The results of our study suggest that perioperative cerebral impairment is reduced in cardiac operations without the use of extracorporeal circulation. Further large-scale studies are needed to show whether this result is reflected by fewer neurologic deficits.

Comparison of standard coronary artery bypass grafting and minimary invasive direct coronary artery bypass grafting. Early and mid-term result

OBJECTIVES

We studied indications and problems involved in minimally invasive coronary artery bypass grafting (MIDCAB).

METHODS

We compared patients profiles, graft patency, stenosis severity, morbidity, mortality, long-term survival and freedom from cardiac accidents in 174 patients undergoing elective standard coronary artery bypass grafting (CABG) and 128 undergoing between January 1996 and March 1999.

RESULTS

No statistically difference was seen in gender, diabetes mellitus, renal failure, cerebrovascular accident, multi-vessel disease ratios, or left main trunk stenosis between 2 groups. Internal thoracic artery graft patency was 97% (114/118) and the rate of anastomotic stenosis (> 50%) was 9% (10/118) compared to 96% (213/221) in the MIDCAB group. The 3-year survival rate was 91% in the MIDCAB group and 92% in the CABG group and freedom from cardiac accidents, most involving pericutaneus transluminal coronary angioplasty retreatment, was 66% in the MIDCAB group and 88% in the CABG group.

CONCLUSION

Although patency and stenosis incidence did not differ between 2 groups, freedom from cardiac accidents was lower in the MIDCAB group.

Off-pump versus on-pump coronary artery bypass surgery and postoperative renal dysfunction

Renal dysfunction is a serious complication after coronary bypass surgery with cardiopulmonary bypass (CABG). Because duration of cardiopulmonary bypass (CPB) is associated with renal outcome, it has been proposed that avoidance of CPB with off-pump coronary bypass (OPCAB) may reduce perioperative renal insult. We therefore tested the hypothesis that OPCAB is associated with less postoperative renal dysfunction compared with CABG surgery. With IRB approval, we gathered data for 690 primary elective coronary bypass patients (OPCAB, 55; CABG, 635). Perioperative change in creatinine clearance (DCrCl) was calculated by using preoperative (CrPre) and peak postoperative (CrPost) serum creatinine values, and the Cockroft-Gault equation (DCrCl = CrPreCl - CrPostCl). Univariate and linear multivariate tests were used in this retrospective analysis; P: < 0.05 was considered significant. Multivariate analysis did not identify OPCAB surgery as an independent predictor of DCrCl. However, previously reported associations of PreCrCl, age, and diabetes with DCrCl were confirmed. Power analysis demonstrated an 80% power to detect a 7.0 mL/min DCrCl difference between study groups. In this retrospective study, we could not confirm that OPCAB significantly reduces perioperative renal dysfunction compared with CABG surgery. Our findings suggest that reduction of renal risk alone should not be an indication for OPCAB over CABG surgery.

IMPLICATIONS

Retrospective analysis did not identify any significant difference in perioperative change in creatinine clearance after coronary revascularization with cardiopulmonary bypass compared with off-pump coronary surgery.

Exposure and mechanical stabilization in off-pump coronary artery bypass grafting via sternotomy

Although off-pump coronary artery bypass grafting (CABG) is gaining popularity, obtaining exposure and stabilization of coronary arteries located on the lateral and inferior wall of the heart may be problematic. The aim of this study is to describe strategies and techniques of coronary exposure and mechanical stabilization that may be used to achieve total myocardial revascularization of the beating heart.

Hemodynamic effects of elevation and stabilization of the heart during off-pump coronary surgery

BACKGROUND

Coronary artery bypass grafting (CABG) surgery is now being performed without the use of cardiopulmonary bypass (CPB). To achieve complete myocardial revascularization off-CPB, a technique has been developed to expose target coronary arteries while hemodynamics are maintained.

METHODS

Complete myocardial revascularization was performed in 18 consecutive patients. Exposure of target coronary arteries was achieved by a "single-suture" technique, placed in the oblique sinus of the pericardium. Traction on the suture elevates and rotates the heart, thereby exposing all target coronary arteries. Cardiac index (CI) and intracardiac pressures were measured with a Swan-Ganz catheter during the different phases of the operation.

RESULTS

All patients were successfully operated on without CPB. There were no postoperative complications or deaths. There were no major hemodynamic changes during the different stages of the operation; in other words, CI was unchanged during elevation of the heart and snaring of the main coronary branches. Pulmonary artery wedge pressure (PAWP) increased markedly during occlusion and stabilization of the circumflex coronary artery (p < 0.05). A marked increase in CI and cardiac output (CO) from baseline values was also recorded before chest closure (p < 0.05).

CONCLUSION

Complete myocardial revascularization can be achieved safely without CPB. The single-suture technique allows for exposure of all target coronary arteries without hemodynamic compromise.

Complete myocardial revascularization on the beating heart with epicardial stabilization: anesthetic considerations

OBJECTIVE

To describe an anesthetic management protocol for patients undergoing cardiac surgery with multiple coronary artery bypass grafts without cardiopulmonary bypass (off-pump CABG surgery) by median sternotomy with mechanical stabilization.

DESIGN

Retrospective nonrandomized analysis.

SETTING

Tertiary care hospital.

PARTICIPANTS

Sixty-six consecutive patients on whom off-pump CABG surgery by median sternotomy was attempted.

INTERVENTIONS

Anesthesia was induced with a combination of etomidate and fentanyl; pancuronium bromide was given for muscle relaxation; and anesthesia was maintained with isoflurane, desflurane, or sevoflurane in 100% oxygen. Maintenance of normothermia was attempted by keeping the room temperature at 70 degrees F, warming all fluids to 41 degrees C, and using 2.5 L/min of fresh gas flows and a heat and humidity exchanger. When available, a convective forced-air blanket was used to cover patients' head and shoulders. Patients who were not slated for revascularization of the circumflex vessels and who had good ventricular function received central venous pressure monitoring (26%); all other patients received a pulmonary artery catheter.

MEASUREMENTS AND MAIN RESULTS

Of the 66 patients, 36% required an epinephrine infusion at a mean rate of 1.45+/-2.05 microg/min intraoperatively to maintain hemodynamic stability; 25% required inotropic support for < 12 hours in the intensive care unit.

CONCLUSION

Institution of systematic hemodynamic management was associated with the successful completion of the surgical procedure in 61 patients (92%). Only 5 patients required conversion to regular CABG surgery with cardiopulmonary bypass.

Surgical management of unstable angina and symptomatic coronary artery disease

The treatment of coronary artery disease and, in particular, acute coronary syndromes has evolved from watchful waiting to an early aggressive intervention strategy. Patients are currently receiving either percutaneous or surgical revascularization. Several major clinical trials have identified those patients mostly likely to benefit from surgical intervention. These patients typically include those with left-main coronary artery disease, triple vessel disease with decreased left ventricular function, and other clinical risk factors. As a result of these studies, unique needs and outcomes of special populations have been identified. This article will present an overview of surgical treatment of coronary artery disease with emphasis on patient selection with particular attention to women, older persons, diabetic patients, and innovations in surgical techniques that may improve patient outcomes.

Coronary revascularization of the circumflex system: different approaches and long-term outcome

BACKGROUND

Minimally invasive direct coronary artery bypass, without cardiopulmonary bypass, through a left lateral thoracotomy approach (lateral MIDCAB), is a safe alternative to coronary artery bypass surgery using cardiopulmonary bypass (on-pump CABG) of the circumflex system via median sternotomy. However, it is unknown whether lateral MIDCAB may yield an improved long-term outcome over the conventional on-pump median sternotomy approach.

METHODS

We compared the perioperative outcomes of patients undergoing lateral MIDCAB (n = 34) versus conventional on-pump CABG of the circumflex system (n = 16) from June 1996 to July 1999. The two groups were similar with respect to baseline characteristics and risk stratification. Patients who required only one or two grafts for complete revascularization were included.

RESULTS

Lateral MIDCAB patients had a lower need than on-pump CABG patients for intraoperative (12% MIDCAB vs 43% on-pump CABG, p = 0.03) and postoperative transfusions (29% vs 69%, p = 0.01), had fewer neuropsychologic changes (0% vs 19%, p = 0.03), and had a lower rate of postoperative atrial fibrillation (12% vs 44%, p = 0.02). Lateral MIDCAB was also associated with a significantly lower postoperative length of stay (5 +/- 2 vs 7 +/- 3 days, p = 0.02). Actuarial survival at a mean period of follow-up of 19 +/- 11 months was 97% for the lateral MIDCAB versus 88% for the on-pump CABG group (p = 0.6). Event-free survival was 88% for lateral MIDCAB versus 81% for on-pump CABG (p = 0.1).

CONCLUSIONS

Lateral MIDCAB may safely be performed in patients with isolated coronary artery disease of the circumflex system with improved early morbidity and an abbreviated hospital stay compared with conventional median sternotomy on-pump CABG.

Coronary Surgery: off-pump and port access

Attempts to minimize the invasiveness of cardiac surgery have focused on decreasing access trauma and eliminating cardiopulmonary bypass. The initial procedures, minimally invasive direct coronary artery bypass (MIDCAB, limited access beating heart) and port access (limited access arrested heart), have become niche procedures. Off-pump coronary artery bypass (OPCAB, median sternotomy beating heart) presently accounts for approximately 15% of all coronary bypass operations performed in the United States. Morbidity and cost appear to be decreased with these procedures. Feasibility trials of endoscopic coronary bypass surgery using robotic devices are underway in many centers. It is anticipated that over the next 5 years the alternative approaches to conventional coronary artery bypass surgery will continue to grow as methods of coronary revascularization.

Off-pump coronary artery bypass grafting: initial experience at one community hospital

BACKGROUND

This study reports one cardiac surgical center's experience with off-pump coronary artery bypass (OPCAB) and compares clinical risk factors and outcomes with a group of patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass at the same institution.

METHODS

Data on preoperative risk factors, intraoperative clinical markers, and postoperative outcomes were collected prospectively on all patients undergoing cardiac surgical procedures at our institution. From January 1, 1999, through October 7, 1999, 332 patients underwent OPCAB procedures at our institution. This group was compared with 445 consecutive patients undergoing CABG at the same institution during the period of January 1, 1998, through November 30, 1998.

RESULTS

The two groups were similar with respect to preoperative clinical risk factors. Intraoperative data showed OPCAB patients tended to have fewer grafts performed and had a lower frequency of multiple grafts to obtuse marginal vessels. Outcomes showed no differences in the incidence of perioperative stroke, mediastinitis, reexploration for bleeding, pulmonary complications, new renal failure, postoperative atrial fibrillation, or transfusion of blood products. Patients in the OPCAB group had fewer perioperative myocardial infarctions and lower incidence of postoperative low cardiac output syndrome. A higher percentage of OPCAB patients had surgical lengths of stay of 5 days or less. The OPCAB group tended to have a lower in-hospital mortality rate but this difference did not reach statistical significance.

CONCLUSIONS

Off-pump coronary artery bypass grafting with revascularization of all coronary artery segments is a safe and effective procedure that can be performed with equal or improved outcomes and shorter surgical lengths of stay compared with CABG with cardiopulmonary bypass.

Midterm angiographic assessment of coronary artery bypass grafting without cardiopulmonary bypass

BACKGROUND

Coronary bypass surgery that provides good long-term graft patency can be performed on the beating heart as a viable alternative to conventional coronary artery bypass grafting (CABG).

METHODS

From September 1993 to December 1996, 696 patients underwent CABG on the beating heart at the Koşuyolu Heart and Research Hospital in Istanbul. Among them, 70 patients were chosen randomly for angiographic assessment of off-pump coronary artery bypass grafting.

RESULTS

The interval from operation to angiography varied from 24 to 61 months (mean, 36.1+/-10.9 months). The patency rate of left internal mammary-left anterior descending artery anastomoses was 95.59% (patency achieved in 65 of 68 patients) and of vein grafts was 47.06% (patency achieved in 16 of 34 patients) (p < 0.0001). The patency rates of grafts anastomosed to the left anterior descending artery were significantly higher than the rates of the grafts anastomosed to the other coronary arteries (95.71% versus 45.45%, p < 0.0001). Multivariate analysis showed that graft type (p < 0.0001) and hyperlipidemia (p = 0.023) were significant predictors for graft occlusion. Left ventricular function improved significantly after CABG (p = 0.04). Reintervention (using percutaneous transluminal cardiac angioplasty) and reoperation rates were 0.97% and 1.4%, respectively.

CONCLUSIONS

Off-pump coronary artery bypass grafting appears to produce midterm and long-term patency rates that are comparable to those of conventional techniques; that is especially true in cases of arterial conduits and of conduits anastomosed to the left anterior descending artery.