Cardiopulmonary Bypass Coronary Artery Bypass Grafting Research Articles

Abstract WMP67: Pump Brain - A Leading Cause of Cortical Cerebral Microbleeds

Introduction: A major cause of cerebral microbleeds (CMBs) is underrecognized and has been attributed to cerebral amyloid angiopathy (CAA) throughout modern medicine. CMBs are acquired by patients undergoing cardiopulmonary bypass (CPB). CPB is utilized for heart and lung transplants, aorta repairs, valve surgeries, mass resections, and coronary artery bypass grafting (CABG) which alone accounts for 400k patients per year. CABGs can be done off CPB in certain patients. Due to their distribution, these CMBs are attributed to CAA, leading to confounding research and suboptimal patient care, especially in those requiring anticoagulation. Methods: This was a single-center, IRB approved, retrospective cohort study of patients who underwent CPB and had postop MRI between 11/1/11 and 3/1/23. Preop and additional postop MRIs were analyzed if available. Outcomes included number and distribution of CMBs, presence of superficial siderosis, FAZEKAS, and CPB duration. We also analyzed MRIs of patients who had off CPB CABG during the same period. Results: Out of 60 patients who underwent CPB, 60 had predominantly cortical CMBs on postop MRI, with a mean of 50 CMBs, and mean age of 61. The 6 patients who had CABG off CPB had 0 CMBs. Higher CMBs were associated with longer CPB duration and with procedures that are associated with more blood loss (p< 0.05). Despite having CMBs, no CPB patients had superficial siderosis, and they had relatively low FAZEKAS scores. Nineteen of the CPB patients had future MRIs and had no evidence of CMB progression. Conclusion: Cortical CMBs are associated with procedures that use CPB and are not seen in off CPB CABG. The CMBs may be related to utilization of cardiotomy suction that exclusively uses roller pumps. CBP related CMBs are a unique clinical entity that is not associated with the progressive cognitive changes and bleeding risk of CAA. While no significant short-term changes are noted, their mechanism and natural history requires further investigation.

Off-Pump and On-Pump Coronary Artery Bypass Grafting Are Associated With Similar Graft Patency, Myocardial Ischemia, and Freedom From Reintervention: Long-Term Follow-Up of a Randomized Trial

The Surgical Management of Arterial Revascularization Therapies trial was conceived to rigorously compare completeness of revascularization, clinical outcomes and resource utilization in unselected patients referred for elective, primary coronary artery bypass grafting randomly assigned to undergo off-pump (OPCAB) or conventional on-pump coronary artery bypass grafting using cardiopulmonary bypass (CPB). The goal of this follow-up study was to compare long-term survival, graft patency, myocardial ischemia, and clinical outcomes among survivors who volunteered to return for clinical evaluation and imaging studies. Two hundred unselected patients with multivessel coronary artery disease were randomly assigned to OPCAB or CPB coronary artery bypass grafting between March 2000 and August 2001. All-cause mortality was determined by individual patient contact and referencing the Social Security Death Master File. Of 140 survivors, 87 volunteered to return after a minimum of 6.8 years (maximum, 8.4 years; mean, 7.5 years) for assessment of graft patency (computed tomographic angiography) and myocardial ischemia (cardiac positron emission tomography and 12-lead electrocardiogram). Age at follow-up ranged from 38 to 90 years (mean, 68 years). There were 26 deaths from all causes among OPCAB patients and 31 among CPB patients as of March 30, 2009. Graft patency was similar between groups among 622 grafts assessed by angiography before hospital discharge (99% OPCAB versus 97.7% CPB; p=0.22, Fisher's exact test), among 511 grafts assessed by angiography at 1 year (93.6% OPCAB versus 95.8% CPB; p=0.33), and among 190 grafts assessed by computed tomographic angiography at late follow-up (76% OPCAB versus 83.5% CPB; p=0.44). Twelve of 34 OPCAB (35.3%) and 16 of 39 CPB patients (41.0%) had any ischemia on positron emission tomography scanning (p=0.62). Four OPCAB patients (11.8%) and 9 CPB patients (23.1%) had an ischemic region in excess of 10% of myocardium (p=0.21). At late follow-up, recurrent angina had occurred in 11 of 43 (25.6%) OPCAB patients and 5 of 44 (11.4%) CPB patients (p=0.09). Percutaneous reintervention had been performed at the discretion of blinded local cardiologists in 1 of 43 (2.3%) OPCAB patients and 1 of 44 (2.3%) CPB patients (p=1.0). No patient in either group has undergone repeat CABG. In this randomized trial, off-pump and on-pump coronary artery bypass grafting were associated with similar early and late graft patency, incidence of recurrent or residual myocardial ischemia, need for reintervention, and long-term survival.

Off-pump coronary revascularization in chronic dialysis-dependent patients: early outcomes at a single institution

Atherosclerotic vascular disease is the leading cause of morbidity and mortality in patients with end-stage renal disease. Several authors reported that chronic dialytic patients have a high operative risk when submitted to coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CPB) whereas little information exists about off-pump myocardial revascularization in these patients. Between January 2000 and December 2008, 17 consecutive patients (12 men, mean age of 62.3 +/- 12.3 years) with end-stage renal failure maintained on chronic hemodialysis underwent isolated off-pump CABG at our center. To evaluate this approach we compared the outcomes of off-pump revascularization with those obtained in the same period in 23 patients (20 men, mean age of 64.0 +/- 9.7 years), with the same preoperative features, who underwent conventional CABG on the arrested heart using CPB. Off-pump revascularization in end-stage renal disease patients showed a satisfactory incidence of mortality and morbidity rates. When compared with conventional CPB CABG group, off-pump patients had a lower incidence of bleeding, transfusions, ventilation support time, length of inotropic support and perioperative myocardial infarction. Also ICU and hospital stay and incidence of new-onset atrial fibrillation were lower in off-pump CABG patients. In our experience, avoidance of CPB in end-stage renal disease patients was associated with an acceptable incidence of postoperative complications and of major adverse events. Off-pump CABG is a safe and effective method of myocardial revascularization in chronically dialyzed patients that should strongly be taken in consideration when planning the surgical strategy in this selected cohort of patients, although multicentric prospective randomized controlled trials are strongly recommended.

Surgical trauma affects the proinflammatory status after cardiac surgery to a higher degree than cardiopulmonary bypass

Cytokines contribute to the development of the systemic inflammatory response syndrome or multiple-organ failure frequently observed after cardiopulmonary bypass-supported cardiac surgery. To quantify the contribution of bypass-induced versus trauma-induced inflammatory response after coronary artery bypass grafting, we examined plasma cytokine levels in 120 patients with coronary artery disease who were treated with or without cardiopulmonary bypass-assisted procedures. Patients were treated in accordance with one of the following protocols: (1) elective percutaneous coronary intervention without cardiopulmonary bypass (n = 69), (2) cardiopulmonary bypass-supported percutaneous coronary intervention (cardiopulmonary bypass-percutaneous coronary intervention; n = 10), and (3) cardiopulmonary bypass-supported coronary artery bypass grafting (cardiopulmonary bypass-coronary artery bypass grafting; n = 41). Cytokine levels (picograms/milliliter) were measured by enzyme-linked immunosorbent assay from plasma samples obtained at various time points. Interleukin-6 was measured in blood samples from all 3 patient populations. The maximum interleukin-6 level was 13.6 +/- 22.3 pg/mL in the percutaneous coronary intervention group, 170.4 +/- 165.4 pg/mL in the cardiopulmonary bypass-percutaneous coronary intervention group, and 640.3 +/- 285.7 pg/mL in the cardiopulmonary bypass-coronary artery bypass grafting group. Interleukin-6 levels were significantly different, and the 95% confidence intervals did not overlap. In the cardiopulmonary bypass-percutaneous coronary intervention group, bypass duration correlated well with interleukin-6 production ( r = 0.915; P < .001), whereas these parameters did not correlate in patients who underwent cardiopulmonary bypass-coronary artery bypass grafting ( r = 0.307; P = .054). These findings support the suggestion that surgical trauma and cardiopulmonary bypass contribute to the inflammatory response after cardiac surgery, although trauma may contribute to a higher degree.

Uniform safety of beating heart surgery using the octopus tissue stabilization system.

Minimally invasive coronary artery bypass grafting (CABG) has been facilitated by the introduction of the Octopus Tissue Stabilization system (OTS). OTS improves exposure immobilizing the heart with minimal hemodynamic effects allowing multivessels off cardiopulmonary bypass (CPB) CABG. The purpose of this study was to compare the utilization and clinical outcome of the OTS in three geographically distinct centers. 239 patients who underwent OTS-CABG at Allegheny University Hospital/Medical College of Pennsylvania, Harrisburg Hospital, and Park Nicollet Clinic/HealthSystem Minnesota were reviewed. Age, acuity of patients, and number and type of vessels bypassed were recorded. Complications, mortality, length of hospital stay, incidence of conversion to CPB and blood transfusions, and operating room costs were compared to risk matched control patients who underwent CPB CABG during the same period. Results were similar in all three centers. The average age was 62.3 years. Emergent operation was necessary in 7%-10% of patients, the operations averaged 1.8 grafts/patient. Arteries bypassed were LAD, DIAG, OM, RCA, PDA, and RPLB. There were 96% of operations completed without CPB. Morbidity was low (12%). Atrial fibrillation and blood transfusion rate were decreased. Mortality was 0 compared with a predicted mortality of 1.6%. Hospital length of stay was shorter and operating room costs were 61% lower. OTS provides predictable reproducible immobilization allowing the performance of single and multiple off-pump CABG to almost all coronary branches with minimal morbidity and decreased costs in a variety of patients. Similar findings from three different centers suggests that these results are easily reproducible.

Uniform Safety of Beating Heart Surgery Using the Octopus Tissue Stabilization System

AbstractBackground and purpose: Minimally invasive coronary artery bypass grafting (CABG) has been facilitated by the introduction of the Octopus Tissue Stabilization system (OTS). OTS improves exposure immobilizing the heart with minimal hemodynamic effects allowing multivessels off cardiopulmonary bypass (CPB) CABG. The purpose of this study was to compare the utilization and clinical outcome of the OTS in three geographically distinct centers. Methods: 239 patients who underwent OTS-CABG at Allegheny University Hospital/Medical College of Pennsylvania, Harrisburg Hospital, and Park Nicollet Clinic/HealthSystem Minnesota were reviewed. Age, acuity of patients, and number and type of vessels bypassed were recorded. Complications, mortality, length of hospital stay, incidence of conversion to CPB and blood transfusions, and operating room costs were compared to risk matched control patients who underwent CPB CABG during the same period. Results: Results were similar in all three centers. The average age was 62·3 years. Emergent operation was necessary in 7%-10% of patients, the operations averaged 1·8 graftdpatient. Arteries bypassed were LAD, DIAG, OM, RCA, PDA, and RPLB. There were 96% of operations completed without CPB. Morbidity was low (12%). Atrial fibrillation and blood transfusion rate were decreased. Mortality was 0 compared with a predicted mortality of 1·6%. Hospital length of stay was shorter and operating room costs were 61% lower. Conclusions: OTS provides predictable reproducible immobilization allowing the performance of single and multiple off-pump CABG to almost all coronary branches with minimal morbidity and decreased costs in a variety of patients. Similar findings from three different centers suggests that these results are easily reproducible.