On-pump Procedures Research Articles

Off-pump versus on-pump coronary artery bypass grafting in patients with left ventricular dysfunction

ObjectiveUsing data from the Japan Adult Cardiovascular Surgery Database, we evaluated the prognostic influence of off-pump technique in patients with low ejection fraction who underwent coronary artery bypass grafting. MethodsWe analyzed 2187 patients with an ejection fraction <0.30 who underwent primary, nonemergency, isolated coronary artery bypass grafting between 2008 and 2012, as reported in the Japan Adult Cardiovascular Surgery Database. Patients were divided into on-pump (n = 1134; 51.1%) and off-pump (n = 1053; 48.9%) coronary artery bypass grafting groups. Propensity-score matching for 20 preoperative variables was performed, and early mortality and morbidity were compared between matched groups. ResultsPropensity-score matching created 918 pairs. Of the 918 patients in the off-pump group, conversion to an on-pump procedure occurred in 56 (6.1%). Compared with on-pump, off-pump technique was associated with significantly lower incidences of 30-day death (1.7% vs 3.7%; P = .01), operative death (3.3% vs 6.1%; P = .006), mediastinitis (1.9% vs 3.4%; P = .041), reoperation for bleeding (0.9% vs 3.5%; P < .001), and prolonged ventilation (8.2% vs 13.4%; P < .001). Comparison of patients undergoing off-pump versus on-pump procedures demonstrated no significant differences in the incidence of stroke (1.5% vs 2.1%; P = .38), renal failure (6.1% vs 7.4%; P = .26), and postoperative dialysis (3.1% vs 4.4%; P = .14). Institutional volume-adjusted analysis confirmed most of these results. ConclusionsOff-pump coronary artery bypass grafting is associated with significantly reduced early mortality and morbidity in patients with an ejection fraction <0.30.

Myocardial conditioning techniques in off-pump coronary artery bypass grafting.

Off-pump coronary artery bypass surgery by avoiding cardioplegic arrest seems to reduce the risk of ischemic myocardial injury. However, even short-term regional ischemic periods, hemodynamic instability and arrhythmias associated with the procedure can be responsible for myocardial damage. Conditioning, a potential cardio-protective tool during on-pump cardiac surgery, has hardly been investigated in the context of off-pump surgery. There are virtually no large trials on remote ischemic preconditioning and the majority of reports have focused on central ischemic conditioning. Similarly, volatile anesthetic agents with conditioning effect like ischemic preconditioning have been shown to reduce cardiac injury during on-pump procedures but have not been validated in the off-pump scenario. Here, we review the available evidence on myocardial conditioning, either with ischemia/reperfusion or volatile anesthetic agents in patients undergoing off-pump coronary artery surgery.

Effect of On-Pump CABG (Roller Versus Centrifugal Systems) on MCP-1, TNFsR and IL6 Behaviour

Background We aimed to evaluate the cytokines monocyte chemotactic protein 1 (MCP-1), TNF soluble receptor (TNF-sR1) and interleukin 6 (IL-6) behavior in patients submitted to CABG (coronary artery bypass grafting) surgeries comparing roller to centrifugal extracorporeal circulation (ECC) pumping systems. Methods We randomized prospectively 43 adults who had elective on-pump CABG with the use of a roller (group I; n = 22) or a centrifugal system (group II; n = 21). Plasma levels of MCP-1, TNF-sR1 and IL-6 were determined by Elisa before the induction of anaesthesia (T1), 35 min after initiation of ECC (T2), 1 min after aortic declamping (T3), and 2, 6 and 24 h after the operation (T4, T5 and T6, respectively). The two groups were matched according to preoperative features. The groups I and II showed similar perioperative characteristics and clinical postoperative outcomes. The plasma levels of MCP-1 and TNF-sR1 reached a peak at T4 and T5 in both groups. MCP-1 in group I was significantly higher (P = 0.020) than in group II at T5, while plasma levels of TNF-sR1 in group I were significantly (P = 0.028) higher than in group II at T4. In both groups, the levels of IL-6 reached a peak at T5. Group I showed higher IL-6 plasma levels (P = 0.006). Conclusion We conclude that both roller and centrifugal pumps induce inflammatory responses to on-pump CABG procedures but higher levels of MCP-1, TNF-sR and IL6 were verified using roller systems.

Real-time in-plane ultrasound-guided supraclavicular approach to subclavian vein cannulation in cardiac surgery: An underused approach

BackgroundAlthough the subclavian vein has several anatomical advantages; it has been underused in cardiac surgery. In this feasibility study, the author aimed to test real-time in-plane ultrasound-guided supraclavicular subclavian vein cannulation during elective cardiac surgical procedures as an acceptable alternative for the routinely used internal jugular vein.MethodsThis prospective feasibility study included forty adult patients undergoing elective on-pump cardiac surgical procedures performed during the period from June 2012 to January 2013. The aim of this study is to test real-time in-plane ultrasound-guided supraclavicular subclavian vein cannulation in terms of time of placement, number of attempts to puncture the vein, inadvertent arterial puncture, usability before and after sternal retractor expansion, and catheter tip position.ResultsSuccessful cannulation of the subclavian vein was accomplished in an average time of 43.8 (14.9) s. The median number of skin punctures was 1 (range 1–3). All lumens of the catheters were usable both before and after using the sternal retractor in all cases except one. The central venous pressure waveform has been recorded in all cases except one. Using transesophageal echocardiography all catheter tips were found to lie within 1.6 cm from the crista terminalis.ConclusionReal-time in-plane ultrasound-guided supraclavicular subclavian vein cannulation is an easy and safe approach to be used in adult patients undergoing cardiac surgical procedures.

Pain and inflammatory response following off-pump coronary artery bypass grafting

Inflammation and pain are two common clinical issues following cardiac surgery, which are important to patient outcomes. This article reviews the literature regarding inflammation and pain following cardiac surgery with special emphasis on off-pump cardiac surgery. Off-pump surgery is associated with decreased intraoperative inflammatory response compared with procedures using cardiopulmonary bypass; however, the postoperative pattern of inflammatory response is similar to on-pump procedures. Multimodal analgesic regimens and protocol-based approaches to pain management improve analgesia compared to conventional approaches. Off-pump cardiac surgeries although known to decrease the inflammatory burden do not appear to impact the overall patient outcomes. Recent evidence indicates the prothrombotic tendency following off-pump procedures, which could be related to the time course of inflammation following off-pump cardiac surgery. There might be some benefit of off-pump procedures regarding neurological and renal function that needs further studies. Pain management following off-pump procedures is similar to that of patients undergoing on-pump cardiac surgery. Better caregiver and patient education is crucial for improving pain control following cardiac surgery. Analgesic regimens need to consider adjuvants and regional analgesic techniques and patient-controlled modalities while providing care.

Morbidity But Not Mortality Is Decreased After Off-Pump Coronary Artery Bypass Surgery

Off-pump coronary bypass surgery (CABG) has been advocated to avoid the physiologic perturbations related to cardiopulmonary bypass and improve outcomes compared with on-pump CABG. Previous reports have been inconsistent, and thus its benefits remain uncertain. This retrospective study compared outcomes between on-pump and off-pump CABG from a large multicenter cohort of propensity-matched patients. The study consisted of 21,640 patients (19,639 [90.8%] on-pump, 2,001 [9.2%] off-pump) who underwent isolated CABG between January 1, 2008, and June 30, 2011, and were entered into a statewide collaborative database. Univariate analysis compared 37 baseline characteristics between on-pump and off-pump procedures. Patients were matched 1:1 based on similarities in propensity scores derived from statistically significant baseline characteristics. Propensity scores and surgery type were used in conditional logistic regression models for predicting each of 14 postoperative outcomes using the sample of 3,898 matched procedures. Patients undergoing off-pump CABG had significantly fewer complications overall, including decreased red blood cell transfusion, stroke, intensive care unit and ventilator time, reoperation for bleeding, and length of stay. There was no difference in renal failure, wound infection, discharge location, or 30-day readmission rate. Although off-pump patients received fewer bypass grafts per patient (2.5 ± 1.2 versus 3.0 ± 1.1; p < 0.001), operative mortality was similar for the two groups (1.8% on-pump versus 2.3% off-pump; p = 0.30). Off-pump CABG was associated with less morbidity, shorter length of stay, and similar mortality compared with on-pump procedures, suggesting that it can be a safe and effective alternative to standard on-pump CABG. However, the limited use of off-pump CABG in this multicenter analysis may restrict the generalizability of these results, and realistically defines the limited degree of acceptance of this technique in a real-world environment.

Antiplatelet therapy at the time of coronary artery surgery: can a personalized approach improve outcomes?

We read with great interest the recently published multicentre cohort study by Kremke et al. [1]. Patients exposed to antiplatelet therapy (APT) at the time of coronary artery surgery (CAS) had greater postoperative bleeding volumes and greater transfusion requirements [1]. Exposure to clopidogrel, but not aspirin, was associated with greater reoperation rates and was an independent risk factor for severe postoperative bleeding, although mean bleeding volumes were not significantly different in the aspirin and clopidogrel subgroups [1]. Despite current guidelines, it is apparent that many patients are proceeding with CAS without the 5-day delay off clopidogrel. The efficacy of platelet inhibition with clopidogrel varies widely among patients, from intensive platelet inhibition to poor platelet response [2], and these variations could, to some degree, explain the non-significant differences in mean bleeding volumes in the aspirin and clopidogrel subgroups [1]. The effect of clopidogrel on bleeding mainly depends on two factors: (i) observed platelet inhibition, which depends on inherent platelet activity prior to clopidogrel administration and platelet inhibitory response to clopidogrel and (ii) newborn platelets ability to restore normal aggregation after clopidogrel discontinuation. Therefore, the use of suitable point-of-care platelet function analysers seems to be reasonable in this field. Recently, we found aspirin(P = 0.014) and clopidogrel(P = 0.003) sensitive platelet function tests to be predictive of excessive postoperative bleeding in patients following CAS [2]. Of note, 76.3% patients were transfused with no significant differences among the groups with regard to the preoperative APT administration regime (P = 0.636) [2]. However, transfused patients had significantly lower values of aspirin-sensitive platelet function tests (P = 0.002) [2]. In our opinion, the study cohort is somehow heterogeneous. Eligible procedures were either isolated CAS or CAS combined with aortic valve replacement (AVR) [1]. AVR certainly extends the duration of cardiopulmonary bypass, which was recently described as a predictor of transfusion requirements [3]. After matching, authors reported a slightly greater use of antifibrinolytic drugs in the APT group [1]. Both on-pump and off-pump procedures were included [1]. Authors reported that off-pump surgery and perioperative use of tranexamic acid were associated with a lower risk of severe postoperative bleeding [1]. The use of antifibrinolytic drugs should be equally balanced since there is evidence that antifibrinolytic therapy reduces bleeding and transfusion outcomes [4]. It would be interesting to see if exclusion of CAS + AVR and off-pump CAS patients would bring different results. During the study period, thromboelastometry-guided blood component therapy became available at two of three participating centres [1]. At the same time, multivariate analysis revealed that surgery at one of the participating centres was one of independent risk factors for severe postoperative bleeding [1]. Spiess et al. [5] reported thromboelastography-guided haemostatic management to have significantly reduced the incidence of overall transfusion and mediastinal re-exploration due to excessive bleeding. Thus, perhaps one could assume that one centre, which was found to be independent risk factor for severe postoperative bleeding, was in fact the one without thromboelastometry guided transfusion therapy available. The largest extent of chest tube output together with the greatest transfusion rates, was observed in the subgroup of patients exposed to dual APT [1]. Those results are in line with the results recently published by Miceli et al. [6]. Further incremental platelet inhibition may be observed in the group of patients receiving dual APT. Therefore, the role of aspirin and clopidogrel administration management should be separately assessed by drug-specific platelet function tests, thus facilitating an individual therapeutic approach for discontinuation management of each antiplatelet agent preoperatively.

Early and mid-term results of off-pump endarterectomy of the left anterior descending artery

Many patients referred for coronary artery bypass surgery (CABG) today have diffusely diseased coronary vessels, and some of them may require coronary endarterectomy to provide adequate revascularization. Most reports of coronary endarterectomy describe an on-pump procedure. As off-pump coronary artery bypass graft has become safer and more routine, there is renewed interest in off-pump coronary endarterectomy. We report on our series of patients who underwent off-pump coronary endarterectomy of the left anterior descending (LAD) artery using an open endarterectomy technique. All patients undergoing open heart surgery at The Mount Sinai Medical Center are entered into a state-mandated, audited database. A retrospective review of this database revealed 12 patients between January 2008 and June 2012 who underwent off-pump endarterectomy of the LAD as part of their coronary revascularization. Additional data were collected from a review of the patients' charts. There were a total of 12 patients, with a mean age of 72 ± 4 years. Nine (75%) were male and 3 (25%) were female. Comorbidities included hypertension in 11 (92%) patients, dyslipidaemia in 10 (83%), diabetes in 8 (67%), renal failure in 6 (50%) and stroke in 1 (8%). The mean number of diseased coronary territories was 3 ± 0.4 (range 2-3), and the mean number of coronary bypass grafts performed was 4 ± 0.8 (range 2-5). Eight patients required transfusion with packed red blood cells (67%). One (8%) patient was converted from off-pump to on-pump. The mean intensive care unit stay was 3 ± 2.8 (range 1-8 days), and the mean hospital length of stay was 15 ± 13 (range 4-54 days). Postoperative follow-up (mean 24 ± 19 months, range 1-53) is complete, and no ischaemic events have occurred in the early and mid-term follow-up period. We conclude that off-pump endarterectomy of the LAD is a viable option for patients with diffuse LAD disease.

Abstract 18409: Long-Term Mortality Following On- and Off-Pump Coronary Artery Bypass Graft Surgery

Background: There are limited data on the relative survival following on- and off-pump coronary artery bypass graft (CABG) surgery during follow-up periods longer than 5 years. Objectives: To examine the difference in 7-year mortality after on- and off-pump isolated CABG surgery. Methods: A total of 5,940 on-pump and 2,640 off-pump isolated CABG patients discharged between October 1 and December 31, 2000 were identified using the New York State's Cardiac Surgery Reporting System. The patients' vital statuses through the end of 2007 were determined by matching to the National Death Index. We fit a logistic regression model that used the baseline patient characteristics to predict the probability (propensity) of receiving off-pump procedure. Using a 1:1 ratio, we then matched on- and off-pump CABG patients based on the propensity of receiving off-pump procedure. We compared the Kaplan-Meier survival curves for on- and off-pump CABG using the matched data, and fit a Cox proportional hazards model to obtain the hazard ratio for death for off-pump in comparison to on-pump procedures. We also conducted subgroup analysis and tested the significances of interactions between treatment (on- or off-pump) and a number of baseline risk factors. Results: A total of 2,634 off-pump patients were matched to on-pump patients. During the follow-up until the end of 2007, 727 on-pump and 780 off-pump patients died. The respective 7-year survival rates for off- and on-pump were 71.3% and 73.1% (P=0.09), and the hazard ratio for death (off- vs. on-pump) was 1.11 (95% confidence interval: 1.00 to 1.24, P=0.06). In addition, there were no differences in 7-year mortality between off- and on-pump CABG surgery in the subgroups of patients defined by age, sex, the number of diseased coronary arteries, left main coronary disease, ejection fraction, history of myocardial infarction, and comorbidities such as cerebrovascular disease, peripheral vascular disease, congestive heart failure, and diabetes. Conclusions: There was no difference in long-term morality between on- and off-pump CABG surgery.

Preconditioning With Repeated Hyperbaric Oxygen Induces Myocardial and Cerebral Protection in Patients Undergoing Coronary Artery Bypass Graft Surgery: A Prospective, Randomized, Controlled Clinical Trial

To evaluate the cerebral and myocardial protective effects of hyperbaric oxygen preconditioning in both on-pump and off-pump coronary artery bypass graft surgery. A prospective, randomized, single-blinded study including patients scheduled for elective on-pump or off-pump surgery between December 2007 and February 2009. A tertiary care university teaching hospital. Forty-nine elective on-pump or off-pump coronary artery bypass graft surgery patients. Patients were randomized to either the control (15 patients with on-pump procedure and 10 patients with off-pump procedure, respectively) or hyperbaric oxygen (HBO; 14 patients with on-pump procedure and 10 patients with off-pump procedure, respectively) groups. Patients in the HBO groups underwent preconditioning for 5 days before surgery. On-pump coronary artery bypass graft surgery patients preconditioned with HBO had significant decreases in S100B protein, neuron-specific enolase, and troponin I perioperative serum levels compared with the on-pump control group. Postsurgically, patients in the on-pump HBO group had a reduced length of stay in the intensive care unit and a decreased use of inotropic drugs. Serum catalase activity 24 hours postoperatively was significantly increased compared with the on-pump control group. In the off-pump groups, there was no difference in any of the same parameters. Preconditioning with HBO resulted in both cerebral and cardiac protective effects as determined by biochemical markers of neuronal and myocardial injury and clinical outcomes in patients undergoing on-pump coronary artery bypass graft surgery. No protective effects were noted in off-pump coronary artery bypass graft surgery.

Tranexamic Acid Reduces Blood Loss After Off-Pump Coronary Surgery

Bleeding and the need for allogeneic transfusions are still problems after off-pump coronary artery bypass grafting (OPCAB) surgery. We therefore evaluated the effects of an antifibrinolytic, tranexamic acid, on postoperative bleeding and transfusion requirements in patients undergoing OPCAB surgery. Two hundred thirty-one consecutive patients scheduled for elective OPCAB were enrolled in the study. Using a double-blind method, the patients were randomly assigned to receive either tranexamic acid (bolus 1 g before surgical incision followed by an infusion of 400 mg/h during surgery; n = 116) or a placebo (infusion equivalent volume of saline solution; n = 115). The primary outcome was 24-hour postoperative chest tube drainage. Allogeneic transfusion, mortality, major morbidities, and resource utilization were also recorded. In comparison with the placebo group, the patients receiving tranexamic acid had a significant reduction in chest tube drainage at 6 hours (270 ± 118 mL vs 416 ± 179 mL, P < 0.001) and 24 hours (654 ± 224 mL vs 891 ± 295 mL, P < 0.001). There was also a significant reduction in allogeneic red blood cell transfusions (47 vs 31.9%, P = 0.019) and fresh frozen plasma (29.6% vs 17.2%, P = 0.027) transfusions. There were no differences in mortality, morbidity, and resource utilization between the 2 groups. Tranexamic acid reduces postoperative chest tube drainage and the requirement for allogeneic transfusion in off-pump coronary surgery.

Can cardiac surgery cause hypopituitarism?

Apoplexy of pituitary adenomas with subsequent hypopituitarism is a rare but well recognized complication following cardiac surgery. The nature of cardiac on-pump surgery provides a risk of damage to the pituitary because the vascular supply of the pituitary is not included in the cerebral autoregulation. Thus, pituitary tissue may exhibit an increased susceptibility to hypoperfusion, ischemia or intraoperative embolism. After on-pump procedures, patients often present with physical and psychosocial impairments which resemble symptoms of hypopituitarism. Therefore, we analyzed whether on-pump cardiac surgery may cause pituitary dysfunction also in the absence of pre-existing pituitary disease. Twenty-five patients were examined 3-12 months after on-pump cardiac surgery. Basal hormone levels for all four anterior pituitary hormone axes were measured and a short synacthen test and a growth hormone releasing hormone plus arginine (GHRH-ARG)-test were performed. Quality of life (QoL), depression, subjective distress for a specific life event, sleep quality and fatigue were assessed by means of self-rating questionnaires. Hormonal alterations were only slight and no signs of anterior hypopituitarism were found except for an insufficient growth hormone rise in two overweight patients in the GHRH-ARG-test. Psychosocial impairment was pronounced, including symptoms of moderate to severe depression in 9, reduced mental QoL in 8, dysfunctional coping in 6 and pronounced sleep disturbances in 16 patients. Hormone levels did not correlate with psychosocial impairment. On-pump cardiac surgery did not cause relevant hypopituitarism in our sample of patients and does not serve to explain the psychosocial symptoms of these patients.

Cardiac displacement-induced hemodynamic instability during off-pump coronary artery bypass surgery and its predictors

Emergent conversion to an on-pump procedure during an off-pump coronary artery bypass surgery (OPCAB) due to hemodynamic instability is associated with increased morbidity and mortality. The aim of this study was to evaluate the predictors of hemodynamic instability associated with mechanical heart displacement during OPCAB and the fate of these patients. Data of 494 patients who underwent elective, isolated OPCAB between December 2006 and April 2010 were reviewed. Hemodynamic instability was defined as mixed venous oxygen saturation (SvO(2) ) <60% during grafting. Pre-operative variables including the presence of diastolic dysfunction and mitral regurgitation (MR) were evaluated for their predictive value for hemodynamic instability by logistic regression analysis. Outcome variables were also compared between patients who developed hemodynamic instability and those who did not. In univariate analysis, body mass index, diabetes mellitus, chronic obstructive pulmonary disease (COPD), left ventricular ejection fraction, diastolic dysfunction, MR ≥ grade 1, higher creatinine and the use of diuretics were identified as risk factors. In multivariate analysis of these variables, COPD and creatinine remained as independent risk factors for hemodynamic instability. These patients also had significantly lower cardiac output and SvO(2) after sternum closure and a higher incidence of composite morbidity end points. COPD and pre-operative creatinine level were identified as independent risk factors of mechanical heart displacement-induced hemodynamic instability during OPCAB. As these patients were associated with significantly lower SvO(2) even at the end of surgery and with adverse outcome, consideration may be given to initiate preemptive measures to increase SvO(2) before or during grafting.

Is there an optimal minimally invasive technique for left anterior descending coronary artery bypass?

BackgroundThe aim of this retrospective study was to evaluate the clinical outcome of three different minimally invasive surgical techniques for left anterior descending (LAD) coronary artery bypass grafting (CABG): Port-Access surgery (PA-CABG), minimally invasive direct CABG (MIDCAB) and off-pump totally endoscopic CABG (TECAB).MethodsOver a decade, 160 eligible patients for elective LAD bypass were referred to one of the three techniques: 48 PA-CABG, 53 MIDCAB and 59 TECAB. In MIDCAB group, Euroscore was higher and target vessel quality was worse. In TECAB group, early patency was systematically evaluated using coronary CT scan. During follow-up (mean 2.7 ± 0.1 years, cumulated 438 years) symptom-based angiography was performed.ResultsThere was no conversion from off-pump to on-pump procedure or to sternotomy approach. In TECAB group, there was one hospital cardiac death (1.7%), reoperation for bleeding was higher (8.5% vs 3.7% in MIDCAB and 2% in PA-CABG) and 3-month LAD reintervention was significantly higher (10% vs 1.8% in MIDCAB and 0% in PA-CABG). There was no difference between MIDCAB and PA-CABG groups. During follow-up, symptom-based angiography (n = 12) demonstrated a good patency of LAD bypass in all groups and 4 patients underwent a no LAD reintervention. At 3 years, there was no difference in survival; 3-year angina-free survival and reintervention-free survival were significantly lower in TECAB group (TECAB, 85 ± 12%, 88 ± 8%; MIDCAB, 100%, 98 ± 5%; PA-CABG, 94 ± 8%, 100%; respectively).ConclusionsOur study confirmed that minimally invasive LAD grafting was safe and effective. TECAB is associated with a higher rate of early bypass failure and reintervention. MIDCAB is still the most reliable surgical technique for isolated LAD grafting and the least cost effective.

In Vitro Evaluation of the Effect of Cardiac Surgery on Cancer Cell Proliferation

Operative stress of cardiovascular surgery can alter the blood levels of various physiologically active substances (e.g., cytokines, growth factors), and thus potentially affect cancer cell proliferation. How the combination of changes in blood levels of these substances affects cancer cells has not been adequately addressed. We investigated the stimulatory capacity on cancer cells of serum from patients after cardiovascular surgery, using a novel in vitro assay method. The subjects were 22 patients undergoing cardiovascular surgery, consisting of 11 off-pump and 11 on-pump procedures. Blood was sampled from each subject immediately before surgery, immediately after surgery, and after transfer to the intensive care unit. Human lung cancer cells were exposed to the serum of each blood sample from each patient, and an MTT assay was conducted to evaluate cell proliferation. Serum samples of all patients showed an inhibitory effect for lung cancer cell proliferation. This inhibitory effect was lower in postoperative serum compared with serum samples before surgery. As a result, lung cancer cell proliferation was better with postoperative serum samples than preoperative serum samples. The proliferation rate after surgery, when it was compared with preoperative serum, was significantly higher in patients with on-pump procedures than in patients with off-pump procedures. The results of this study suggest that the operative stress of cardiovascular surgery induces changes in serum to make it less inhibitory for the cancer cell proliferation. This phenomenon is greater in patients with extracorporeal circulation.

Tratamento cirúrgico da fibrilação atrial paroxística em esternotomia mediana usando procedimento de Maze sob circulação extracorpórea padrão

The aim of article is to give a brief description to the surgical strategies for patients with lone atrial fibrillation without associated cardiac operations, and present the possible indications of on-pump Maze procedures through a mid-sternotomy approach.

Safe Introduction and Quality Control of New Methods in Coronary Surgery

Introduction:The first part of the paper analyses off pump coronary bypass surgery (OPCAB), which is compared with traditional on-pump procedures (ONCAB). Furthermore ,the paper evaluates the use of a new automatic device for performance of the proximal anastomosis and finally the effect of intracoronary shunt on myocardial ischemia during OPCAB. The main goal of the paper is to demonstrate the importance of careful clinical studies during introduction of the new techniques in cardiac surgery.Methods:Statistical analysis was performed on a large clinical database from Buffalo, NY, USA comparing OPCAB and ONCAB. Subsequently, a sequential controlled clinical study compared patients operated with a new automatic connector device to patients operated with classic suture technique. Finally a randomized study was performed to evaluate the effect of the use of an intracoronary shunt during construction of distal anastomosis.Results:The studies from Buffalo demonstrated reduced complications rates in high risk patients when OPCAB techniques were used. The use of connector devices in saphenous venous anastomosis was clearly inferior to standard technique. Intracoronary shunt was found to be beneficial by preventing ischemia.Discussion:Numerous studies have studied the results of OPCAB vs ONCAB and although results are variable it seems that OPCAB is advantageous in high risk patients, while in low risk patients there are much less if any benefit. The results of the studies of connector devices caused the product to be taken off the market. The value of shunt in OPCAB was clearly demonstrated by the randomized studies.Conclusion:The investigations presented in this paper clearly demonstrates the importance of well-designed studies when new surgical methods are introduced. In the present period of rapid technological development, carefully controlled, un-biased clinical trials are crucial to preserve patient safety and avoid unjustified societal cost.

Effects of on-pump and off-pump coronary artery bypass grafting on left ventricular relaxation and compliance: a comprehensive perioperative echocardiography study

The short-term effect of coronary artery bypass grafting (CABG) on diastolic function is only moderately investigated. Furthermore, it remains unknown whether avoidance of cardioplegic arrest by an off-pump CABG procedure has advantages over on-pump procedure regarding diastolic relaxation and compliance. We investigated whether components of diastolic function would be improved the day after CABG depending on the type of the surgical procedure. Spontaneously breathing on-pump (n = 20) and off-pump CABG (n = 12) patients underwent a comprehensive transthoracic echocardiography examination the day before and the day after elective CABG, including transmitral and pulmonary vein flow parameters, colour M-mode flow propagation velocity (Vp) and tissue Doppler assessment of the average mitral annulus diastolic velocity (Em). Isovolumic relaxation and E-wave deceleration time were corrected for heart rate (IVRTcHR and DTcHR). Left ventricular (LV) relaxation time (τ) and LV operating stiffness (LVOS) were calculated. Overall and independent from operation type and preload, CABG decreased IVRTcHR (107 ± 20 vs. 93 ± 15 ms) (P < 0.01) and τ (54 ± 10 vs. 45 ± 10 ms) (P < 0.01), increased Vp (49 ± 22 vs. 75 ± 37 cm/s) (P < 0.01), and increased Em (6.6 ± 2.0 vs. 7.3 ± 1.3 cm/s, P = 0.06), indicating improved relaxation. LVOS increased (0.13 ± 0.06 vs. 0.22 ± 0.05 mmHg/mL) (P < 0.01), compatible with an impaired compliance. A similar improvement in relaxation and impairment in compliance were observed in both groups. Myocardial relaxation improved the day after CABG irrespective of the use of cardiopulmonary bypass with cardioplegic arrest. Impairment in compliance could not be prevented by the avoidance of cardioplegia.

On-Pump versus Off-Pump CABG

To the Editor: In the Veterans Affairs Randomized On/Off Bypass (ROOBY) trial, Shroyer et al. (Nov. 5 issue)1 assigned 2203 patients to receive coronary-artery bypass grafting (CABG) either with the use of cardiopulmonary bypass (on-pump CABG) or without such bypass (off-pump CABG). The trial enrolled low-risk male patients in whom avoidance of cardiopulmonary bypass was unlikely to greatly improve the expected excellent outcomes.2 In a majority of patients, CABG was performed by surgical trainees under the supervision of attending surgeons who were remarkably inexperienced in the off-pump procedure and much more experienced in the on-pump procedure. The reported 12.4% rate of intraoperative conversion from planned off-pump CABG to on-pump CABG was five times the rate reported in the national database of the Society of Thoracic Surgeons3 and is an explicit indictment of the off-pump inexperience of surgeons, trainees, and anesthesia– nursing teams participating in the ROOBY trial.4 It is illogical to conduct a randomized trial comparing patient outcomes with alternative surgical techniques among surgical operators who have grossly asymmetric experience and expertise with the two procedures that are being compared. This is the “fatal flaw” of the ROOBY trial. Off-pump CABG is a technically challenging surgical procedure that offers substantial benefit to patients at high risk for death and complications with on-pump CABG.3,5 It remains a very important tool for surgical coronary revascularization. John D. Puskas, M.D.

The role of EuroSCORE in patients undergoing off-pump coronary artery bypass

European System for Cardiac Operative Risk Evaluation (EuroSCORE) has been used to predict the postoperative mortality rate for patients undergoing open-heart surgery. The contributions of EuroSCORE in off-pump coronary artery bypass grafting (CABG) has not yet clearly elucidated. Consecutive patients of isolated off-pump CABG performed from 2000 when we start performing 'routine' off-pump procedures were stratified using the additive EuroSCORE. Incidence of postoperative mortality, morbidity, and recovery were assessed, and compared to an historical cohort of on-pump procedures performed between 1991 until 1998 when CABG had been routinely performed under on-pump. There were 1318 patients in the off-pump and 1162 patients in the on-pump group. EuroSCORE of the off-pump group was significantly higher than that of the on-pump group. In both the on- and off-pump groups, mortality, total incidence of major complications, heart failure, and renal failure, and three parameters of recovery time were well correlated with EuroSCORE; however, the discriminatory power of the EuroSCORE model was always better in the on-pump group than in the off-pump group. Stroke was correlated with EuroSCORE only in the on-pump group. Pneumonia, mediastinitis postoperative myocardial infarction, or mediastinitis was not correlated with EuroSCORE in either group. In the off-pump group, postoperative major complication was reduced and postoperative recovery was shortened significantly, compared to those in the on-pump group. In off-pump CABG, EuroSCORE can, but not as good as in on-pump CABG, predict mortality, certain major postoperative complications, and postoperative recovery. This suggests off-pump technique appears to modify the risk stratification of the patients undergoing CABG.