Coronary perfusion methods during off-pump coronary artery bypass: results of a randomized clinical trial

BACKGROUND: Several techniques are being used to perform off-pump coronary artery bypass (OPCAB) grafting. This three-armed clinical trial was performed to determine whether one OPCAB method of coronary perfusion was superior over the others with respect to myocardial protection and performance. METHODS: Over the course of 11 months, 151 consecutive unselected patients underwent elective first-time OPCAB grafting by sternotomy performed by a single surgeon. Patients were prospectively randomized to receive one of three OPCAB coronary perfusion treatments: (1) no coronary perfusion (NCP), ie, OPCAB using no coronary perfusion during the distal anastomosis or graft perfusion after the distal anastomosis until all the proximal anastomoses were completed; (2) passive coronary perfusion (PCP), providing distal coronary perfusion during the anastomosis and immediate graft perfusion after the distal anastomosis by means of a passive cannula from the aorta; or (3) active coronary perfusion (ACP), providing assisted distal coronary perfusion and graft perfusion by means of an in-line pump (perfusion-assisted direct coronary artery bypass. Hemodynamic and biochemical data were recorded to disc continuously throughout the operation and postoperatively. RESULTS: With no statistically significant differences in the three treatment groups with respect to patient age, left ventricular systolic or diastolic function, and extent and distribution of coronary disease or grafts performed, cardiac performance postoperatively was superior in the active coronary perfusion group compared to the groups receiving either passive coronary perfusion or no coronary perfusion (p < 0.001). In addition, troponin I levels were lower in the coronary perfusion groups (PCP and ACP) (p = 0.023). CONCLUSIONS: Providing active coronary perfusion during the anastomosis and after each distal anastomosis by using an in-line pump resulted in superior myocardial protection and performance during OPCAB surgery when compared to either no coronary perfusion or passive coronary perfusion.     

Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial

BACKGROUND: Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity. METHODS: Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared. RESULTS: Coronary artery bypass grafting was associated with more cerebral microemboli (575 +/- 278.5 CABG versus 16.0 +/- 19.5 OPCAB (median +/- semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p < or = 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p < or = 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 +/- 1256 mL CABG versus 789 +/- 586 mL OPCAB, p = 0.02) and required more blood (3.9 +/- 5.8 U CABG versus 1.2 +/- 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 +/- 6.0 U CABG versus 0.5 +/- 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 +/- 21.2 hours CABG versus 7.3 +/- 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 +/- $5,320 CABG versus $17,780 +/- $4,390 OPCAB, p < 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS). CONCLUSIONS: Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost.     

Health-related quality of life following off-pump versus on-pump coronary artery bypass grafting in elderly moderate to high-risk patients: a randomized trial.

OBJECTIVE: Previous trials comparing coronary artery bypass grafting (CABG) with or without extracorporeal circulation have mainly enrolled selected patients at younger age and low risk. Patient-reported health-related quality of life has not been significantly different. We compared health-related quality of life in elderly moderate to high-risk patients randomized to either off-pump or on-pump surgery. METHODS: The study is a sub-study of the randomized Best Bypass Surgery Trial that compares off-pump to on-pump treatment, with respect to peri- and postoperative mortality and morbidity in patients with a moderate to high-predicted preoperative risk. After randomization and before heart surgery, 120 consecutive patients were asked to fill in the Medical Outcomes Study Short Form 36 (SF-36) and Major Depression Inventory (MDI) diagnostic scale for self-report of health-related quality of life. Three months after surgery, the same questionnaires were mailed to the patients. RESULTS: The response rate was 96.5%. At baseline, the groups were comparable except for a difference in educational level. Both groups improved in all eight SF-36 domains from baseline to 3 months. No statistical differences were seen between the groups except for changes in mean difference of role limitation due to emotional problems, which was significantly (P=.04) improved in favour of the on-pump group. Depression scores remained unchanged within and between the two surgical groups. CONCLUSIONS: Both on-pump and off-pump patients improved in health-related quality of life scores after CABG surgery. No clinically relevant difference between the groups could be demonstrated.     

Vein versus polytetrafluoroethylene in above-knee femoropopliteal bypass grafting: five-year results of a randomized controlled trial

OBJECTIVE: Controversy still exists whether polytetrafluoroethylene is equivalent to vein as bypass graft material for the above-knee femoropopliteal bypass. Therefore, a prospective randomized trial was performed to compare vein with polytetrafluoroethylene for femoropopliteal bypasses with the distal anastomosis above the knee. METHODS: Between January 1993 and December 1996, 151 above-knee femoropopliteal bypasses were performed. The indications for operation were severe claudication in 120 cases, rest pain in 20 cases, and ulceration in 11 cases. After randomization, 75 reversed saphenous venous bypasses and 76 polytetrafluoroethylene bypasses were performed. RESULTS: No perioperative mortality was seen, and 5% of the patients had minor infections of the wound, not resulting in loss of the bypass, the limb, or life. After 5 years, 38% of the patients had died and 7% were lost to follow-up. Only once was the saphenous vein necessary for coronary artery bypass grafting. Primary patency rates after 5 years were 75.6% for venous bypass grafts and 51.9% for polytetrafluoroethylene grafts (P =.035). Secondary patency rates were 79.7% for vein and 57.2% for polytetrafluoroethylene bypasses (P =.036). In the venous group, 14 bypasses failed, leading to five new bypasses. In the polytetrafluoroethylene group, 29 bypasses failed, leading to 16 reinterventions. For these 16 new bypasses, in four cases, the ipsilateral preserved saphenous vein was used. In both groups, one above-knee amputation and one below-knee amputation had to be performed. CONCLUSION: We conclude after 5 years of follow-up of this randomized controlled trial that a bypass with saphenous vein has better patency rates at all intervals and needs fewer reoperations. Saphenous vein should be the graft material of choice for above-knee femoropopliteal bypasses and should not be preserved for reinterventions. Polytetrafluoroethylene is an acceptable alternative if the saphenous vein is not available.     

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.     

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.     

Desmopressin acetate in uncomplicated coronary artery bypass surgery: a prospective randomized clinical trial

Bleeding in coronary artery bypass procedures increases morbidity and exposes patients to the risks associated with blood transfusion. Desmopressin acetate (DDAVP), a synthetic vasopressin analogue, may limit bleeding during cardiac surgery. In a prospective randomized trial, the authors evaluated the ability of DDAVP to reduce perioperative bleeding during uncomplicated coronary bypass operations. Sixty-two patients who underwent coronary artery bypass grafting were randomized to receive intraoperatively either a placebo or DDAVP. Both groups were similar with respect to operative characteristics and preoperative hematologic profiles, von Willebrand factor levels increased postoperatively in both placebo (2.77 +/- 1.06 versus 2.17 +/- 1.51 U) and DDAVP groups (2.75 +/- 0.94 versus 1.80 +/- 0.88 U). Only the increase in the DDAVP groups was significant (p less than 0.001). There was no difference in total blood loss between the placebo (1826 +/- 849 ml) and DDAVP groups (1716 +/- 688 ml). Total red cell transfusions were similar in placebo (3.4 +/- 1.3 units of blood) and DDAVP groups (3.6 +/- 0.8 units). These results do not support the intraoperative use of DDAVP to reduce perioperative bleeding in routine coronary artery bypass surgery.     

Economic outcome of off-pump coronary artery bypass surgery: a prospective randomized study

Background. Emphasis on cost containment in coronary artery bypass surgery is becoming increasingly important in modern hospital management. The revival of interest in off-pump (beating heart) coronary artery bypass surgery may influence the economic outcome. This study examines these effects.

Methods. Two hundred patients undergoing first-time coronary artery bypass surgery were prospectively randomized to either conventional cardiopulmonary bypass and cardioplegic arrest or off-pump surgery. Variable and fixed direct costs were obtained for each group during operative and postoperative care. The data were analyzed using parametric methods.

Results. There was no difference between the groups with respect to pre- and intraoperative patient variables. Off-pump surgery was significantly less costly than conventional on-pump surgery with respect to operating materials, bed occupancy, and transfusion requirements (total mean cost per patient: on pump, $3,731.6 ± 1,169.7 vs off-pump, $2,615.13 ± 953.6; p < 0.001). Morbidity was significantly higher in the on-pump group, which was reflected in an increased cost.

Conclusions. Off-pump revascularization offers a safe, cost-effective alternative to conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest.     

Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass

BACKGROUND: Myocardial revascularization in diabetic patients is challenging with no established optimum treatment strategy. We reviewed our coronary artery bypass grafting experience to determine the impact of eliminating cardiopulmonary bypass on outcomes in diabetic patients relative to nondiabetic patients. METHODS: From January 1995 through December 1999, 9,965 patients, of whom 2,891 (29%) had diabetes, underwent isolated coronary artery bypass grafting. Diabetic and nondiabetic patients were further divided into groups on the basis of cardiopulmonary bypass use. Twelve percent (346 of 2,891) of diabetic patients and 12% (829 of 7,074) of nondiabetic patients underwent coronary artery bypass grafting without cardiopulmonary bypass; the remainder had coronary artery bypass grafting with cardiopulmonary bypass. Nineteen preoperative variables were compared among treatment groups by univariate analysis. RESULTS: Patients undergoing coronary artery bypass grafting without cardiopulmonary bypass compared with those having coronary artery bypass grafting with cardiopulmonary bypass had higher mean predicted mortalities (diabetic, 3.96% versus 3.72%, p = 0.83; nondiabetic, 3.03% versus 2.86%, p = 0.79). In nondiabetic patients, coronary artery bypass grafting without cardiopulmonary bypass provides an actual and risk-adjusted survival advantage over coronary artery bypass grafting with cardiopulmonary bypass (1.81% versus 3.44%, p = 0.0127; risk-adjusted mortality, 1.79% versus 3.61%, p = 0.007). This survival benefit of coronary artery bypass grafting without cardiopulmonary bypass was not seen in diabetic patients (2.89% versus 3.69%, p = 0.452; risk-adjusted mortality, 2.19% versus 2.98%, p = 0.42). Diabetic patients undergoing coronary artery bypass grafting without cardiopulmonary bypass had fewer complications, including decreased blood product use (34.39% versus 58.4%, p = 0.001), and reduced incidence of prolonged ventilation (6.94% versus 12.10%, p = 0.005), atrial fibrillation (15.90% versus 23.26%, p = 0.002), and renal failure requiring dialysis (0.87% versus 2.75%, p = 0.036). CONCLUSIONS: The survival advantage in nondiabetic patients treated with coronary artery bypass grafting without cardiopulmonary bypass is not apparent in diabetic patients. Coronary artery bypass grafting without cardiopulmonary bypass in diabetic patients is nevertheless associated with a significant reduction in morbidity.