Conventional Extracorporeal Circulation Group Research Articles

Conventional versus minimally invasive extra-corporeal circulation in patients undergoing cardiac surgery: A randomized controlled trial (COMICS).

The trial hypothesized that minimally invasive extra-corporeal circulation (MiECC) reduces the risk of serious adverse events (SAEs) after cardiac surgery operations requiring extra-corporeal circulation without circulatory arrest. This is a multicentre, international randomized controlled trial across fourteen cardiac surgery centres including patients aged ≥18 and <85 years undergoing elective or urgent isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR) surgery, or CABG + AVR surgery. Participants were randomized to MiECC or conventional extra-corporeal circulation (CECC), stratified by centre and operation. The primary outcome was a composite of 12 post-operative SAEs up to 30 days after surgery, the risk of which MiECC was hypothesized to reduce. Secondary outcomes comprised: other SAEs; all-cause mortality; transfusion of blood products; time to discharge from intensive care and hospital; health-related quality-of-life. Analyses were performed on a modified intention-to-treat basis. The trial terminated early due to the COVID-19 pandemic; 1071 participants (896 isolated CABG, 97 isolated AVR, 69 CABG + AVR) with median age 66 years and median EuroSCORE II 1.24 were randomized (535 to MiECC, 536 to CECC). Twenty-six participants withdrew after randomization, 22 before and four after intervention. Fifty of 517 (9.7%) randomized to MiECC and 69/522 (13.2%) randomized to CECC group experienced the primary outcome (risk ratio = 0.732, 95% confidence interval (95% CI) = 0.556 to 0.962, p = 0.025). The risk of any SAE not contributing to the primary outcome was similarly reduced (risk ratio = 0.791, 95% CI 0.530 to 1.179, p = 0.250). MiECC reduces the relative risk of primary outcome events by about 25%. The risk of other SAEs was similarly reduced. Because the trial terminated early without achieving the target sample size, these potential benefits of MiECC are uncertain.

Influence of minimal invasive extracorporeal circuits on dialysis dependent patients undergoing cardiac surgery.

Cardiac surgery in patients on chronic renal dialysis is associated with significant morbidity and mortality. Minimally invasive extracorporeal circuits (MiECC) have shown a positive impact on patient outcome in different high-risk populations. This retrospective study compares the outcome of these high-risk patients undergoing heart surgery either with a MiECC or a conventional extracorporeal circulation (CECC). This is a single-center experience including 131 consecutive dialysis dependent patients undergoing cardiac surgery between January 2006 and December 2016. A propensity score matching was employed leaving 30 matched cases in each group. After propensity score matching the 30-day mortality was significantly lower in the MiECC group (n = 3 (10%) vs n = 10 (33%) in the CECC group, p = .028). Further, intraoperative transfused units of packed red blood cells were lower in the MiECC group (1.4 ± 1.8 units vs 2.8 ± 1.7, p < .001). There are evident advantages to using MiECC in dialysis dependent patients, especially regarding mortality. These findings necessitate additional research in MiECC usage in high-risk populations.

Minimal invasive extracorporeal circulation in comorbid patients

Background: As the severity of comorbid diseases increases, risks of cardiopulmonary bypass (CPB) complications significantly increase. A complex of the procedure’s damaging factors provokes a systemic inflammatory response that in some cases is accompanied by the damage to target organs, transitioning from chronic organ dysfunctions into acute ones. Some studies on the use of minimal invasive extracorporeal circulation (MiECC) systems show their advantage over conventional extracorporeal circulation (CECC); however, the diversity of MiECC systems, patients, and outcomes precludes us from confidently extrapolating these data to older comorbid patients.Objective: To compare the severity of systemic inflammation and treatment outcomes in comorbid patients who underwent cardiac surgery with CECC and MiECC.Methods: We conducted a retrospective cohort study of 760 patients who consecutively underwent elective cardiac operations in 2019-2022. Inclusion criteria: comorbid status (age-adjusted Charlson Comorbidity Index score of ≥6); CPB time ≥90 min. Exclusion criteria: emergency surgery, refusal to participate in the study. A total of 68 patients met the inclusion criteria. We formed 2 study groups based on the extracorporeal circulation method: CECC group (n = 51) and MiECC group (n = 17). Control points: before CPB and 24 hours after the surgery (lactate; creatinine; oxygenation index, hemolysis level). For systemic inflammatory response markers: 1 hour after the CPB start and 24 hours after the CPB end (interleukin 6; interleukin 10; procalcitonin; C-reactive protein; soluble Triggering Receptor Expressed on Myeloid Cells-1 [sTREM-1]). We evaluated respiratory and renal complications, drainage-related hemorrhages, hemostatic disorders, the need for sympathomimetic drugs, and the length of stay in an intensive care unit and inpatient hospital.Results: Between the groups there were no statistically significant differences in gender and anthropometric characteristics, surgery types, and main perfusion parameters. In the CECC group, we observed significantly higher doses of vasoconstrictors (norepinephrine) as well as a decrease in urine output and lung injury and an increase in lactate and hemolysis. The systemic inflammatory response markers were also significantly higher.Conclusion: Compared with CECC, MiECC does not significantly affect the frequency of organ dysfunctions; however, it reduces the severity of the systemic inflammatory response and immune suppression that are trigger mechanisms for multiple organ dysfunction syndrome. It is particularly important for patients with chronic organ dysfunctions. A range of indications for MiECC systems should be defined given its high cost and off-target effect on pleiotropic factors of systemic inflammatory response development. Received 6 April 2023. Revised 17 August 2023. Accepted 18 August 2023. Funding: The study was conducted within the framework of the research project "Development of minimally invasive and hybrid technologies for surgical treatment of heart diseases". Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: A.Sh. Revishvili, G.P. Plotnikov, V.A. PopovData collection and analysis: R.A. Kornelyuk, L.B. Berikashvili, I.P. Komkov, E.S. Malyshenko, V.M. ZemskovStatistical analysis: L.B. BerikashviliDrafting the article: R.A. Kornelyuk, G.P. Plotnikov, L.B. Berikashvili Critical revision of the article: G.P. PlotnikovFinal approval of the version to be published: A.Sh. Revishvili, R.A. Kornelyuk, G.P. Plotnikov, L.B. Berikashvili, I.P. Komkov, E.S. Malyshenko, V.M. Zemskov, V.A. Popov

Initial experience with minimally invasive extracorporeal circulation in coronary artery bypass graft reoperations

Minimally invasive extracorporeal circulation (MiECC) is an established alternative to conventional extracorporeal circulation (CECC) in coronary artery bypass graft surgery (CABG), but data on its use in cardiac reoperations are limited. We aimed to analyse perioperative morbidity and mortality in adult patients undergoing reoperations for isolated CABG using either CECC or MiECC circuits at our centre. In a single centre retrospective observational study of all adult patients undergoing cardiac reoperations for isolated CABG between 2004 and 2016, we identified 310 patients, and excluded those who received concomitant cardiac procedures (n = 205). Of the remaining 105 patients, 47 received isolated redo-CABG using MiECC, and 58 received CECC. Propensity score modelling was performed, and inversed probability treatment analysis was used between the treatment groups. Primary endpoint was 30-day all-cause mortality. Secondary endpoints included major adverse cardiac or cerebrovascular events or need for conversion to CECC. Groups were comparable, apart from a higher incidence of NYHA class III or higher in CECC group (33.5% vs 8.6%, p= 0.004). Shorter times for operation, cardiopulmonary bypass and aortic cross-clamp were observed in the MiECC group. The incidence of postoperative atrial fibrillation was significantly lower with MiECC (22.1%, p = 0.012). No significant difference was observed in all-cause 30-day mortality between the MiECC and CECC groups (6.8% vs. 8.3%, p = 0.81). We found no difference in overall mortality between CECC and MiECC in patients undergoing reoperation for isolated CABG. Furthermore, we found no indication of differences in most outcomes between extracorporeal circuit types. In the case of redo-CABG, MiECC could provide an alternative strategy.

Effects on Cerebral Oxygen Balance in Coronary Artery Bypass Grafting: A Comparison of Conventional and Minimal Extracorporeal Circulation

Objective: To investigate the cerebral oxygen balance difference between minimal extracorporeal circulation (MECC) and conventional extracorporeal circulation (CECC) during coronary artery bypass grafting. Methods: 20 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (CPB) were divided into two groups, the CECC group (n=10) and the MECC group (n=10). Blood withdrawn from radial artery and right jugular vein were analyzed at the following timepoints: during the anesthesia induction (T1), before CPB (T2), the initiation of CPB (T3), aorta crossclamped (T4), after temperature decreased (T5), during stable hypothermia (T6), initiation of rewarming (T7), aorta unclamped (T8), after weaning of CPB (T9), end of the operation (T10).The artery oxygen content (CaO2 ) and cerebral oxygen extraction ratio (OER) were calculated. The mean artery pressure (MAP), hemoglobin (Hb), nasopharyngeal temperature (NPT), and pump perfusion flow were recorded during the operation. Results: (1) MAP and Hb of MECC group were significantly higher than those in the CECC group from T3 to T10 (P&lt;0.05); perfusion flow in MECC group during CPB was significantly lower than those in CECC group (P&lt;0.05); NPT in MECC group was significantly higher than those in CECC group (P&lt;0.05). (2) During T3-T4 and T8-T9, jugular venous oxygen saturation in CECC group was significantly lower than those in MECC (P&lt;0.05); OER in CECC group was significantly higher than those in MECC group (P&lt;0.05). (3) The arterial lactic acid and venous lactic acid in these two groups were decreased gradually from T3 to T10. Thearteriovenous difference in lactic acid in CECC group were higher than those in MECC group during T3-T4 and T8-T9 (P&lt;0.05). Conclusion: Patients undergoing coronary artery bypass grafting with MECC enjoy more stable blood pressure, less intense hemodilution and lighter temperature disturbance than those with CECC, which indicating a better cerebral oxygen balance in CABG.

Propofol pharmacokinetics and pharmacodynamics-a perspective in minimally invasive extracorporeal circulation.

There is limited evidence as to the pharmacokinetic changes expected in adults with extracorporeal technologies. Drugs may be taken up by various components of the cardiopulmonary bypass circuit itself. Issues include the increased volume of the circuit leading to haemodilution; the sequestration of lipophilic drugs within the circuit tubing; and the absorption of proteins, especially albumin, onto the circuit, which can result in increased free drug. However, in this context, the aspect of pharmacokinetics and pharmacodynamics during minimally invasive extracorporeal circulation has not been described and evidenced by scientific studies. In this single-centre control study of 60 patients undergoing isolated coronary artery bypass grafting, we present the results focused on postoperative albumin values and intraoperative propofol dosages in patients undergoing surgery with minimally invasive (n = 30) versus conventional extracorporeal circulation (n = 30). In the minimally invasive extracorporeal circulation group, a lower propofol dosage titrated to a bispectral index of 40-45 was used during coronary artery bypass grafting, and an improvement of postoperative concentration of serum albumin was observed compared to the conventional extracorporeal circulation group.

Impact of minimal invasive extracorporeal circulation on atrial fibrillation after coronary artery bypass surgery.

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery with an incidence between 15% and 50% and pathophysiology not fully known. By choosing the method of extracorporeal circulation with focus on the reduction of systemic inflammatory response, one can potentially decrease the risk of POAF. In this prospective, randomized trial, we compared minimal invasive extracorporeal circulation (MiECC) with conventional extracorporeal circulation (CECC) in the prevention of POAF after coronary artery bypass surgery (CABG). A total of 240 patients who were scheduled for their first on-pump CABG, were randomized to MiECC or CECC. The primary outcome measure was the incidence of first POAF during the first 84 hours after surgery. POAF occurred in 42/120 (35.0%) MiECC patients and 43/120 (35.8%) CECC patients with nonsignificant difference between the groups (OR 1.043, 95% CI 0.591-1.843, P=.884). The first postoperative creatine kinase-MB mass (CK-MBm) value was lower in the MiECC group, 13.95 [10.5-16.7] (median [IQR]) than in the CECC group, 15.30 [11.4-18.9] (P=.036), whereas the use of perioperative dobutamine was higher in the MiECC group, 18/120 (15.0%), than in the CECC group 8/120 (6.7%) (P=.038). The incidence of a stroke, perioperative myocardial infarction, and resternotomy caused by bleeding did not differ in the MiECC and CECC groups. Age (OR 1.08, 95% CI 1.04-1.13, P=.000) and peak postoperative CK-MBm (OR 1.57, 95% CI 1.06-2.37, P=.026) were independent predictors of POAF. MiECC compared to CECC was not effective in reducing the incidence of POAF in patients undergoing CABG.

Impact of minimally invasive extracorporeal circulation on coagulation-a randomized trial.

Minimally invasive extracorporeal circulation (MiECC) is suggested to have favourable impact on blood loss compared to conventional extracorporeal circulation. We aimed to compare the impact of both systems on coagulation. Randomized trial comparing endogenous thrombin-generating potential early after elective coronary surgery employing either MiECC group (n = 30) or conventional extracorporeal circulation group (n = 30). Secondary outcomes were in vivo thrombin generation, bleeding end points and haemodilution, as well as morbidity and mortality up to 30-day follow-up. Compared to the conventional extracorporeal circulation group, the MiECC group showed (i) a trend towards a higher early postoperative endogenous thrombin-generating potential (P = 0.06), (ii) lower intraoperative levels of thrombin-antithrombin complex and prothrombin fragment 1 + 2 (P < 0.001), (iii) less haemodilution early postoperatively as measured by haematocrit and weight gain, but without correlation to coagulation factors or bleeding end points. Moreover, half as many patients required postoperative blood transfusion in the MiECC group (17% vs 37%, P = 0.14), although postoperative blood loss did not differ between groups (P = 0.84). Thrombin-antithrombin complex levels (rs = 0.36, P = 0.005) and prothrombin fragment 1 + 2 (rs = 0.45, P < 0.001), but not early postoperative endogenous thrombin-generating potential (rs = 0.05, P = 0.72), showed significant correlation to increased transfusion requirements. The MiECC group demonstrated significantly lower levels of creatine kinase-MB, lactate dehydrogenase and free haemoglobin indicating superior myocardial protection, less tissue damage and less haemolysis, respectively. Perioperative morbidity and 30-day mortality did not differ between groups. Conventional but not MiECC is associated with significant intraoperative thrombin generation despite full heparinization. No correlation between coagulation factors or bleeding end points with the degree of haemodilution could be ascertained. NCT03216720.

Impact of minimal invasive extracorporeal circulation on the need of red blood cell transfusion.

Minimal invasive extracorporeal circulation may decrease the need of packed red blood cell transfusions and reduce hemodilution during cardiopulmonary bypass. However, more data are needed on the effects of minimal invasive extracorporeal circulation in more complex cardiac procedures. We compared minimal invasive extracorporeal circulation and conventional extracorporeal circulation methods of cardiopulmonary bypass. A total of 424 patients in the minimal invasive extracorporeal circulation group and 844 patients in the conventional extracorporeal circulation group undergoing coronary artery bypass grafting and more complex cardiac surgery were evaluated. Age, sex, type of surgery, and duration of perfusion were used as matching criteria. Hemoglobin <80 g/L was used as red blood cell transfusion trigger. The primary endpoint was the use of red blood cells during the day of operation and the five postoperative days. Secondary endpoints were hemodilution (hemoglobin drop after the onset of perfusion) and postoperative bleeding from the chest tubes during the first 12 hours after the operation. Red blood cell transfusions were needed less often in the minimal invasive extracorporeal circulation group compared to the conventional extracorporeal circulation group (26.4% vs. 33.4%, p = 0.011, odds ratio 0.72, 95% confidence interval 0.55-0.93), especially in coronary artery bypass grafting subgroup (21.3% vs. 35.1%, p < 0.001, odds ratio 0.50, 95% confidence interval 0.35-0.73). Hemoglobin drop after onset of perfusion was also lower in the minimal invasive extracorporeal circulation group than in the conventional extracorporeal circulation group (24.2 ± 8.5% vs. 32.6 ± 12.6%, p < 0.001). Postoperative bleeding from the chest tube did not differ between the groups (p = 0.808). Minimal invasive extracorporeal circulation reduced the need of red blood cell transfusions and hemoglobin drop when compared to the conventional extracorporeal circulation group. This may have implications when choosing the perfusion method in cardiac surgery.

Minimally invasive versus conventional extracorporeal circulation circuits in patients undergoing coronary artery bypass surgery: a propensity-matched analysis.

Minimally invasive extracorporeal circulation circuits provide several advantages compared to conventional extracorporeal circulation circuits. We compared the results of a minimally invasive extracorporeal circulation system with those of conventional extracorporeal circulation system, in patients undergoing isolated coronary artery bypass grafting. We identified 753 consecutive patients who underwent coronary artery bypass grafting at our centre between October 2014 and September 2016. These patients were divided into two groups: a minimally invasive extracorporeal circulation group (M, n = 229) and a conventional extracorporeal circulation group (C, n = 524). Baseline parameters, details of cardiac surgery as well as postoperative complications and outcomes were compared by means of a propensity-matched analysis of 180 matched pairs. The median EuroSCORE II was 1.3%. Transfusion requirement of packed red blood cells (p = 0.002) was lower in Group M compared to conventional extracorporeal circulation systems. There were no differences in hospital mortality or in rates of adverse events between the matched groups. Total in-hospital mortality of the cohort was 1.7%. The use of minimally invasive extracorporeal circulation is associated with a significantly lower use of blood products after isolated coronary revascularisation. There were no differences concerning duration of surgery, complication rates and mortality between the groups. Therefore, the application of minimally invasive extracorporeal circulation systems should be considered as preferred technique in isolated coronary artery bypass grafting procedures.

Minimally Invasive Extracorporeal Bypass in Minimally Invasive Heart Valve Operations: A Prospective Randomized Trial

Minimally invasive extracorporeal circulation (MECC) is predominantly used in coronary operations. Data supporting the benefits of MECC in minimally invasive valve operations are still absent. Patients undergoing either isolated minimally invasive mitral or aortic valve procedures were prospectively randomized to a minimally invasive group (MECC; n= 101) or a conventional extracorporeal circulation group (CECC; n= 99). The procedural and postoperative outcomes were compared, including the levels of inflammation factors (procalcitonin, interleukin [IL]-6, IL-8, and IL-10), tumor necrosis factor-α [TNF-α], and interferon-gamma [IFN-γ]). The demographics were comparable between the groups regarding age (MECC versus CECC, 70.5 ± 10.2 years versus 73.1 ± 8.9 years; P= 0.086), left ventricular function (59.2% ± 13.4% versus 62.1% ± 14.0%; p= 0.302), EuroSCORE (7.4% ± 7.9% versus 6.8% ± 4.0%; p= 0.256), and other comorbidities. Hospital mortality (n= 1 versus n= 3; p= 0.339) and other complications were similar. However, hemoglobin level (111.9 ± 19.0 g/L versus 103.8 ± 14.6 g/L; p= 0.001), the number of packed red blood cells (PRBCs) (1.1 ± 1.9 versus 1.7 ± 1.8; p= 0.003), the levels of ILs (IL-6, 194.0 ± 131.8 pg/mL versus 289.2 ± 62.5 pg/mL; p= 0.020; IL-8, 38.1 ± 27.3 pg/mL versus 45.8 ± 43.4 pg/mL; p= 0.012; IL-10, 29.0 ± 123.9 pg/mL versus 49.9 ± 85.6 pg/mL; p= 0.012), TNF-α (3.8 ± 6.7 ng/mL versus 10.8 ± 47.7 ng/mL; p= 0.049), and IFN-γ (1.9 ± 1.9 pg/mL versus 4.5 ± 2.7 pg/mL; p= 0.027) were in favor of patients in the MECC group. Additionally, those patients had shorter postoperative ventilation time (7.7 ± 8.4 hours versus 9.3 ± 12.9 hours; p= 0.010) and intensive care unit (ICU) stay (1.2 ± 1.2 days versus 2.2 ± 3.8 days; p= 0.047). The intraprocedural data were excellent and comparable in the groups, but postoperative outcomes were better in the MECC group. Thus MECC is preferable to CECC even for minimally invasive valve procedures. These findings strongly support a combined strategy of minimally invasive valve operations and minimally invasive extracorporeal circulation.

Abstract 14571: Prospective Randomized Comparisonof Miniaturized Extracorporeal Circulation System (MECC) versus Conventional Extracorporeal Circulation System (cecc) in the Prevention of Postoperative Atrial Fibrillation (FA) and Other Clinical Results in Cardiac Surgery Patients

Introduction: Postoperative atrial fibrillation (AF) is the most common arrhythmia to occur after cardic surgery with an incidence between 20-45 %. It is associated with increased morbidity, including increased risk of stroke and need for additional treatment and costs. The pathophysiology of postoperative AF is not fully understood.cardiac surgery with extracorporeal circulation is known to be associated with a systemic inflammatory response,which may be in part responsible for postoperative AF. furthermore,foreign surface contact,blood-air contact,abnormal blood flow and hemodilution are broblems related to extracorporeal circulation. Hypothesis and Methods: In this prospective,randomized,open labelled clinical study,240 cardiac surgery patients were randomized either miniaturized extracorporeal circulation (MECC) group or conventional extracorporeal circulation (CECC) group before the surgery. The main outcome measure was the incidence of postoperative atrial fibrillation (AF) during the hospital stay after surgery. Other end points were use of blood products and vasoactive agents and the first (CKMBm) value postoperatively. Results: The incidence of postoperative atrial fibrillation was 43/120 (35.8 %) in the conventional extracorporeal circulation group (CECC) compared with 42/120 (35.0%) in the miniaturized extracorporeal circulation group (MECC) (p=0.893). The use of perioperative vasoactive agents was significantly lower in the (MECC) group compared with (CECC) group . Furthermore, the first postoperative CKMBm value was significantly lower in (MECC) patient group than in (CECC) patient group. There were no difference in the use of blood products between the groups. Conclusion: The clinical use of MECC with cardiac operative patients is safe and results are optimal when this procedure is performed by experienced teams. There were no difference in the incidence of postoperatrive atrial fibrillation (AF) between the groups, but the use of vasoactive agents was lower in (MECC) patient group, than in (CECC) patient group and also the first postoperative (CKMBm) value was lower in the (MECC) group than in (CECC) group.

Minimal extracorporeal circulation (MECC) does not result in less hypertrophic scar formation as compared to conventional extracorporeal circulation (CECC) with dexamethasone

Cardiopulmonary bypass surgery is associated with a systemic inflammatory response through the interaction of air, blood and synthetic components in the bypass system and the physical trauma of surgery. An alternative cardiopulmonary bypass system, minimal extracorporeal circulation (MECC), has shown promising results in terms of reducing the inflammatory response. We hypothesized that this system may reduce pathological excessive scarring. To study this assumption, the effects of MECC and the effects of conventional extracorporeal circulation (CECC) with dexamethasone on skin scarring were compared in a standardized wound-healing model. Pre-sternal scars were evaluated prospectively at four and 12 months postoperatively. The height and width of the scars were measured, using a slide caliper and sonography. The scars were scored using the validated Patient and Observer Scar Assessment Scale. Additional risk factors for hypertrophic scar formation were identified by means of a questionnaire. During surgery, MECC was used in 45 patients and CECC/dexamethasone in 42 patients. Four months postoperatively, 22 patients of the MECC group (49%) and 18 patients in the CECC/dexamethasone group (43%) had developed hypertrophic scars. Twelve months postoperatively, the hypertrophic scars in four patients of the MECC group and in two patients of the CECC/dexamethasone group had become normotrophic. In 18 patients of the MECC group (38%) and 16 patients of the CECC group (41%) the scars remained hypertrophic at 12 months. These differences between the two groups were not statistically significant. MECC does not reduce hypertrophic scar formation compared with CECC with dexamethasone, but its use is more beneficial than the use of CECC/dexamethasone because of the circulatory and immunological advantages and because treatment with dexamethasone can be omitted.

Comparing microvascular alterations during minimal extracorporeal circulation and conventional cardiopulmonary bypass in coronary artery bypass graft surgery: A prospective, randomized study

Minimal extracorporeal circulation (MECC) has been introduced in coronary artery bypass graft (CABG) surgery, offering clinical benefits owing to reduced hemodilution and no blood-air interface. Yet, the effects of MECC on the intraoperative microvascular perfusion in comparison with conventional extracorporeal circulation (CECC) have not been studied so far. The current study aimed to analyze alterations in microvascular perfusion at 4 predefined time points (T1-T4) during on-pump CABG using orthogonal polarization spectral imaging. Forty patients were randomized for being operated on with either MECC or CECC. Changes in functional capillary density (FCD), blood flow velocity, and vessel diameter were analyzed by a blinded investigator. After start of extracorporeal circulation (ECC) and aortic crossclamping (T2), both groups showed a significant drop of FCD, with a significantly higher FCD in the MECC group (206.8 ± 33.6 cm/cm² in CECC group versus 217.8 ± 35.3 cm/cm² in MECC group; P = .034). In the late phase of the ECC (T3), FCD in the MECC group was already recovered, whereas FCD in the CECC group was still significantly depressed (223.1 ± 35.6 cm/cm² in MECC group; P = .100 vs T1; 211.1 ± 36.9 cm/cm² in CECC group; P = .017 vs T1). After termination of ECC (T4), FCD recovered in both groups to baseline. Blood flow velocity tended to be higher in the MECC group, with a significant intergroup difference after aortic crossclamping (T2). Orthogonal polarization spectral imaging data reveal an impairment of microvascular perfusion during on-pump CABG. Changes in FCD indicate a faster recovery of the microvascular perfusion in MECC during the reperfusion period. Beneficial recovery of microvascular organ perfusion could partly explain the perioperative advantages reported for MECC.

Beating-heart coronary artery bypass surgery with the help of mini extracorporeal circulation for very high-risk patients

Left ventricle dysfunction and co-morbidities are responsible for a large number of complications after coronary artery bypass graft (CABG) surgery. The best strategy for these patients, including the use or not and type of extracorporeal circulation (ECC), the use of minimized ECC (MECC), or conventional ECC (CECC), remains unclear. The aim of the present study was to investigate the potential effect of on-pump beating-heart (OPBH) surgery with the help of MECC for CABG in patients with a high-risk EuroSCORE and to compare this strategy to three other different procedures, including OPCAB and MECC or CECC with cardiac arrest. Patients were included if their EuroSCORE was strictly >" xbd="1427" xhg="1404" ybd="1477" yhg="1440"/>9. Four groups were retrospectively compared: an OPCAB, an OPBH, a MECC and a CECC group under cardiac arrest. 214 patients, mean age 74.26 ± 8.5 years, 68.7% male, were operated. Mean EuroSCORE was 12.1 ± 2.9, left ventricular (LV) function 37.4 ± 12.3%, recent myocardial infarction (MI) 49.5%, renal failure 48.1%, chronic obstructive pulmonary disease (COPD) 42.2%, and peripheral vascular disease (PVD) 55.6%. Mean number of grafts per patient was 2.4 ± 0.7. Our study showed that it was possible, in very high-risk patients, to carry out revascularisation with OPBH similar to that using MECC or CECC under cardiac arrest (p=NS). This technique reduces troponin release (3.23 vs 6.56, p<0.01), postoperative myocardial complications (2% vs 8%, p<0.01), cardiotonic drug prescription (15.7% vs 31.3%, p<0.01), ventilation time (4.57H vs 6.48H, p<0.01) and length of stay (LOS) in ICU (2.16 vs 2.53, p=0.02). The OPBH method seems to be safe, secure and effective in this population of very high-risk patients, reducing early complications and multi-organ failure. OPBH surgery, combining MECC without aortic cross-clamping, makes it possible to perform complete revascularization and is an interesting alternative for CABG in high-risk patients.

Effect of closed minimized cardiopulmonary bypass on cerebral tissue oxygenation and microembolization

Coronary artery bypass grafting with cardiopulmonary bypass carries a risk for neurologic complications because of cerebral hypoperfusion and microembolization. The basic goals of a novel closed minimized extracorporeal circulation are to prevent excessive hemodilution and to avoid blood-air interface. The aim of this prospective randomized study was to determine the effect of using the minimized extracorporeal circulation system compared with open conventional extracorporeal circulation on cerebral tissue oxygenation and microembolization. Forty patients undergoing coronary artery bypass grafting (20 in each group) were continuously monitored for changes in cerebral oxygenated hemoglobin and tissue oxygenation index by using near-infrared spectroscopy. Total microembolic count and gaseous embolic count in both median cerebral arteries were monitored with multifrequency transcranial Doppler instrumentation. In the conventional extracorporeal circulation group there was a highly significant reduction in both cerebral oxygenated hemoglobin and tissue oxygenation index from the start to the end of cardiopulmonary bypass (P < .01). The rate of decrease in cerebral oxygenated hemoglobin after aortic cannulation was faster in the conventional extracorporeal circulation group (F test = 9.03, P < .001). No significant changes with respect to cerebral oxygenated hemoglobin or tissue oxygenation index occurred in the minimized extracorporeal circulation group, except at the beginning of rewarming (P < .01). Total embolic count, as well as gaseous embolic count, in the left and right median cerebral arteries was significantly lower in the minimized extracorporeal circulation group (all P < .05). Postoperative bleeding was greater (P < .05) and the transfusion rate was higher (P < .05) in the conventional extracorporeal circulation group. Use of closed minimized cardiopulmonary bypass compared with conventional open cardiopulmonary bypass preserves cerebral tissue oxygenation and reduces cerebral microembolization.