Inertia of success. A response to minimally invasive coronary bypass: a dissenting opinion

Perfusion-assisted beating heart support with a miniature extracorporeal circuit and leukocyte filtration: a 58-year-old patient with severe COPD

Patients with severe chronic obstructive pulmonary disease (COPD) impose a significant risk for postoperative morbidity and mortality requiring cardiovascular surgical intervention and the use of extracorporeal circulation. Recently, we treated a 58-year-old male with acute coronary syndrome complicated with recurrent ventricular arrhythmia, hypoxemia secondary to severe COPD and resolving pneumonia, who required urgent coronary revascularization. A novel operative strategy was used that included beating heart bypass grafting with cardiac decompression and support with a miniature perfusion circuit, kinetic-assisted venous return, rapid autologous priming and leukocyte filtration. The combination of multiple modalities was chosen because the patient was in a pre-existing inflammatory condition and had severe COPD. We herein report our perioperative clinical experience with this patient and the use of multiple modalities for extracorporeal perfusion therapy in managing this challenging case. We believe that, based upon his clinical course of ventilation time (17.4 hours) and postoperative length of hospital stay (5 days), this high risk patient demonstrated a positive clinical outcome as a result of these techniques.

Multivessel off-pump coronary artery bypass grafting can be taught to trainee surgeons

BACKGROUND

Although Off-Pump Coronary Artery Bypass (OPCAB) surgery is being increasingly explored and practised in many cardiac units worldwide, there have been only few reports documenting the training of surgeons in this new technique. The purpose of this study was to address the reproducibility of the OPCAB in a unit where this technique is used extensively.

METHODS

Registry data, notes, and charts of 64 patients who were operated on by four trainee cardiac surgeons over a period of thirteen months at Harefield Hospital, were reviewed retrospectively. These trainees were part of an accredited training program for cardiothoracic training and were trained by a single consultant trainer in a cardiac unit after it had an established recent experience in performing nonselective OPCAB for all in-coming patients. Five (7.8%) patients (with 17 distal anastomoses) consented and underwent early postoperative angiography to check the quality of the grafts and anastomoses.

RESULTS

The mean age of the study patients was 65.6 and the mean Parsonnet score was 9.4. There was a mean of 2.9 grafts per patient and circumflex territory anastomoses were performed in 48 (75%) patients. No operation required conversion to Cardiopulmonary Bypass (CPB). Angiography of the five patients revealed 17 satisfactory (100%) distal anastomoses.

CONCLUSION

With appropriate training, it is possible for trainees to learn OPCAB and perform multivessel revascularization in relatively high-risk patients with good results.

Hemodynamic changes during displacement of the beating heart using epicardial stabilization for off-pump coronary artery bypass graft surgery

OBJECTIVE

To evaluate the hemodynamic alterations during off-pump coronary artery bypass graft surgery to determine the degree of impairment caused and the techniques to rectify them.

DESIGN

Prospective, observational cohort study performed from January 2000 through September 2000.

PARTICIPANTS

Patients (n = 500) with coronary artery disease undergoing multivessel off-pump coronary artery bypass graft surgery using the Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, MN). Unstable patients with ongoing ischemia were excluded from the study.

INTERVENTIONS

All patients were monitored with radial artery and pulmonary artery catheters and continuous transesophageal echocardiography monitoring with a multiplane transducer. The perioperative requirement of an intracoronary shunt, inotropes, or an intra-aortic balloon pump was noted. The effect of the Trendelenburg position and fluids on hemodynamics was observed. The need for defibrillation and institution of emergency cardiopulmonary bypass were major endpoints to determine the inability of the patient to tolerate displacement of the heart.

MEASUREMENTS AND MAIN RESULTS

Mean patient age was 59.3 +/- 11.6 years. There were 204 (40%) patients in the high-risk category; 54 (10.8%) patients had left ventricular ejection fraction <25%. The mean number of grafts was 2.7 +/- 0.8. Vertical displacement of the heart to access the lateral and inferior walls decreased the mean arterial pressure by 18 +/- 4% (p < 0.01), with a concomitant increase in central venous pressure of 66 +/- 18% (p < 0.001). The stroke volume and the cardiac index were reduced by 35.7 +/- 11% (p < 0.001) and 45 +/- 13% (p < 0.001). On transesophageal echocardiography, there was development of new regional wall motion abnormalities in 59.2% and a decrease in global left ventricular functions in 61.2%. The use of inotropes was highest during anastomosis on the posterior wall-78.4% compared with 21.9% for the anterior wall. An intra-aortic balloon pump was used in 55 (11.2%) patients, and 7 (0.71 %) patients had to be put on emergency CPB. The in-hospital mortality was 1.2%.

CONCLUSION

Most patients had hemodynamic changes easily correctable by fluids and inotropes. Monitoring of left ventricular and right ventricular function by transesophageal echocardiography enhances safety of the procedure and is recommended. The use of the Octopus II tissue stabilizer proved to be a safe and versatile means to stabilize the heart during off-pump coronary artery bypass procedures, especially in high-risk patients.

Heart displacement during off-pump CABG: how well is it tolerated?

BACKGROUND

Heart displacement during off-pump coronary artery bypass grafting (CABG) is necessary to expose the anastomosic sites. We analyzed the hemodynamic changes in relation to the grafted arteries.

METHODS

The relationship between surgical exposure and hemodynamic management was assessed in 150 consecutive patients undergoing off-pump CABG utilizing the Octopus Tissue Stabilization System (Medtronic, Minneapolis, MN).

RESULTS

Surgical exposure by anterolateral thoracotomy showed no significant hemodynamic changes. Through sternotomy, stroke volume was significantly reduced by dislocation at all target sites: by 6% at the left anterior descending artery (LAD), 25% at the diagonal branch artery (D), 14% at the right coronary artery (RCA), and 21% at the obtuse marginal artery (OM). The application of head-down positioning (LAD, 56%; D, 74%; RCA, 90%; OM, 96%) increased not only surgical exposure but also preload, producing correction of ventricular filling pressures and output. In a minority of cases, dopamine (3 to 5 microg x kg(-1) x min(-1)) was added to maintain baseline hemodynamic values (LAD, 5%; D, 15%; RCA, 7%; OM, 28%).

CONCLUSIONS

Revascularization during anterolateral thoracotomy was uneventful. The sternotomy approach with heart displacement induced right heart compression. Mainly fluid redistribution was sufficient to correct cardiac output. Once stabilized, systemic circulation remained unchanged during revascularization.

Survey of resident training in beating heart operations

BACKGROUND

"Off-pump" coronary artery operations are done with increasing frequency in the treatment of coronary artery disease. As a result, residents in thoracic surgery have been confronted with the necessity of gaining experience in this innovative approach to coronary surgery. The aim of this study was to assess the importance of training in minimally invasive coronary revascularization as it was perceived by thoracic surgery residents.

METHODS

A postal, multiple-choice survey questionnaire was sent to all cardiothoracic surgery residents (n = 327) of accredited training programs in the United States. Responses were tabulated and analyzed.

RESULTS

The overall response rate was 68% (222 of 327 residents). The attending staff was very interested (37%), or had some interest (63%), in beating heart coronary revascularization. Ninety-eight percent of the programs had at least one surgeon performing off-pump procedures. Although 88% of the responding residents showed some interest in off-pump coronary operations, only 22% of them had performed more than 20 off-pump cases, and even less (12%) had performed more than 20 cases of off-pump complete revascularization, or off-pump circumflex revascularization (4%). Sixteen percent of them had no clinical experience with these techniques. Regarding career intentions, 88% of the residents indicated that off-pump coronary operations were expected to be part of the practice, and 58% of them were interested in pursuing additional training in less invasive heart procedures.

CONCLUSIONS

The results of this survey suggest that training in off-pump coronary revascularization is variable across training programs, and that the majority of residents may not reach proficiency in coronary procedures on the beating heart during their residency. This may adversely affect their future expectations, as 88% of them would like to practice off-pump coronary surgery once the training is completed.

Robotically assisted coronary artery bypass grafting: a prospective single center clinical trial

AIM

This prospective study was performed as a Phase 1 Food and Drug Administration clinical trial to assess the safety and feasibility of robotically assisted coronary artery bypass grafting (CABG).

METHODS

Eighteen patients undergoing elective CABG were enrolled in this study. Full sternotomy was performed in 17 of 18 patients, while cardiopulmonary bypass and cardioplegic arrest was used in all cases. Robotically assisted CABG of the left internal thoracic artery (LITA) to the left anterior descending artery (LAD) was performed through three ports using a robotically assisted microsurgical system. Conventional techniques were used to perform all other grafts. Blood flow in the LITA graft was measured in the operating room, and when necessary, angiography was performed. Six weeks after the operation, all patients underwent selective coronary angiography of the LITA graft.

RESULTS

Robotically assisted coronary artery anastomoses were successfully completed in all patients. Blood flow through the LITA graft was adequate in 16 of 18 patients (89%). The two inadequate grafts were revised successfully by hand. Six weeks after the operation, angiography demonstrated a graft patency of 100% (13 of 13). Mean follow-up has been over 190 days. All patients remain New York Heart Association Angina Class I.

CONCLUSION

Robotic assistance represents an enabling technology that may allow the surgeon to perform endoscopic coronary artery anastomoses. Further clinical trials are needed to explore the clinical potential and value of robotically assisted CABG.

Does multivessel, off-pump coronary artery bypass reduce postoperative morbidity?

BACKGROUND

Off-pump coronary artery bypass (OPCAB) is an emerging procedure. It is assumed that elimination of cardiopulmonary bypass for coronary artery bypass grafting has the potential for reducing postoperative morbidity. This review evaluates the safety and impact of multivessel OPCABG as compared to CABG.

METHODS

A retrospective review of 744 patients undergoing multivessel coronary artery bypass between January 1, 1997, and March 31, 1999, was done. The total population was divided into two groups: group A (n = 609 cardiopulmonary bypass) and group B (n = 135 OPCAB). This consecutive study cohort was elective status, full sternotomy with three or more distal anastomoses performed at a single institution.

RESULTS

The mean risk adjusted predicted mortality was 2.3% in group A and 2.7% in group B (p = NS), with the mean number of distal anastomosis being greater in group A (3.8 vs 3.5/patient, p < 0.001). Major postoperative complications were similar but were not statistically significant between groups. Postoperative blood loss and use of blood transfusions were the only significant variables (p < 0.001).

CONCLUSIONS

Multivessel OPCABG can be safely performed in selected patients. Elimination of cardiopulmonary bypass did not significantly reduce postoperative morbidity. Prospective randomized trials and long-term follow-up are needed to better define patient selection and the role of OPCABG.