Subclavian artery reconstruction in patients undergoing coronary artery bypass grafting.

The presence of occlusive disease of the subclavian artery (SCA) proximal to the origin of the internal thoracic artery (ITA) influences the operative strategy and the outcome of coronary artery bypass grafting (CABG). Of 780 patients who underwent CABG, concomitant SCA occlusive lesions were reconstructed in 13 patients (nine males, four females). The affected SCAs were left-sided in 11 patients, and right-sided and bilateral in one, each. An aortoaxillary bypass utilizing an 8-mm PTFE graft was constructed in nine patients and a carotid-subclavian (C-S) transposition in two, simultaneously with CABG. Percutaneous balloon angioplasty with a stent was performed in two patients prior to CABG. With follow-up periods ranging from 4 to 8.4 years (mean, 6.3 years), aortoaxillary bypass grafts were patent in all patients. Other reconstructive procedures, including a C-S transposition and balloon angioplasty, were performed safely and effectively in off-pump CABG patients. In six patients, the left internal thoracic artery (LITA) could be used as a graft to the coronary artery after SCA reconstruction. Aortoaxillary bypass using an 8-mm PTFE graft is a safe and effective way for simultaneous subclavian reconstruction in patients undergoing CABG. Mid-term patency of the graft is satisfactory. The LITA can be used as a graft to the coronary arteries in selected patients. Preoperative brachial angiography is mandatory in these patients.     

Gastrointestinal complications in patients undergoing coronary artery bypass grafting.

PURPOSE: Gastrointestinal complications (GICs) such as gastroduodenal ulcer, enterocolitis, and ischemic colitis after coronary artery bypass grafting (CABG) are rare, but are associated with high mortality and morbidity. The present study was performed to detect risk factors and to investigate outcomes following GICs after CABG. METHODS: Between January 1992 and December 2001, 17 of 549 patients (3.1%) developed GICs after CABG with cardiopulmonary bypass, presenting with gastrointestinal bleeding due to gastroduodenal ulcer, enterocolitis, or ischemic colitis. We conducted a retrospective analysis of these patients. RESULTS: All patients required emergent treatment for hemorrhage by means of blood transfusion and endoscopic ablation and/or clipping. The following possible predictors of GICs were identified by logistic multivariate analysis: age over 70, diabetes mellitus (particularly insulin-dependent diabetes), history of cerebrovascular disease or history of renal failure and postoperative low output syndrome (LOS). CONCLUSION: Our results suggested that GICs after CABG with cardiopulmonary bypass are rare but can be lethal. Early diagnosis and prompt intervention can be difficult but are potentially life saving for patients in whom GICs develop.     

心瓣膜置换术同期行冠状动脉旁路移植术患者长期预后的危险因素探讨

目的 探讨影响心瓣膜置换术同期行冠状动脉旁路移植术(CABG)患者长期预后的危险因素.方法 57例同期行心脏瓣膜置换术和冠状动脉旁路移植术的患者,同行CABG和主动脉手术13例,同行CABG和双瓣膜手术16例,同行CABG和二尖瓣手术28例;移植血管(1.97±1.36)支.通过随访获取数据,对潜在危险因素先用Cox比例风险模型进行单变量分析,再将有统计学意义(P＜0.05)的危险因素纳入Cox多变量回归.结果 失访2例,随访55例,平均随访时间(57.37±13.98)个月,随访期间共7例死亡;高龄(年龄＞70岁)、术前合并糖尿病、有心肌梗死史、慢性肺疾病和左心室射血分数≤40％为影响心瓣膜置换术和CABG同行患者长期预后的独立危险因素.结论 高龄、术前合并糖尿病、有心肌梗死史、有慢性肺疾病和左心室射血分数过低(≤40％)是影响两类手术同行患者长期预后的危险因素.     

Perioperative melatonin secretion in patients undergoing coronary artery bypass grafting

Melatonin, a neurohormone, plays an important role in adjusting the "biological clock" in humans. We sought to describe perioperative patterns of melatonin secretion in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass (CPB). After IRB approval and written informed consent, 12 male patients scheduled for elective coronary artery bypass grafting under hypothermic CPB were enrolled in the study. During anesthesia, patients' eyes were carefully covered to prevent light effects. Blood samples were taken at specific time points during surgery, every 3 h in the immediate postoperative period, and for 24 h from 6:00 PM of Postoperative Day 2 until 6:00 PM of Postoperative Day 3. Plasma melatonin and cortisol concentrations were measured by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. During surgery, plasma melatonin concentrations were below the minimum sensitivity concentration, yet small concentrations, without circadian variation, were detected during the immediate postoperative period. During Postoperative Days 2 and 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity (r = 0.480; P < 0.01). Plasma cortisol concentrations in the immediate postoperative period were significantly larger than those before the induction of anesthesia (P < 0.01). Only three patients regained circadian secretion of cortisol. We concluded that melatonin and cortisol secretion was disrupted during cardiac surgery with CPB and in the immediate postoperative period. However, circadian rhythms of melatonin were present in most patients from Postoperative Day 2. Only 30% of the patients regained circadian rhythm of cortisol secretion. IMPLICATIONS: Melatonin is a hormone that plays an important role in adjusting the biological clock in humans and that regulates secretion of various other hormones. We studied melatonin secretion in patients undergoing cardiac surgery with cardiopulmonary bypass. Melatonin secretion was disturbed during and immediately after surgery but had recovered a circadian rhythm 24 h later, raising the question of whether melatonin should be supplemented before cardiac surgery.     

Autologous platelet sequestration in patients undergoing coronary artery bypass grafting

OBJECTIVES: Blood conservation remains an important issue for patients undergoing cardiac surgery with cardiopulmonary bypass. Platelet sequestration (PSQ) is an aggressive autologous blood conservation method, whose effectiveness is still debated. The main objective of the present study was to evaluate whether PSQ reduces postoperative blood transfusion requirements in patients undergoing coronary artery bypass grafting (CABG) and to determine if PSQ is a cost-effective blood conservation method. MATERIAL AND METHODS: All adult patients admitted for CABG entered the study. Exclusion criteria were: recent blood transfusion (<7 days), a platelet count of 150x10(3)/microl or less, hematocrit less than 35% and body weight 50 kg or less. The sequestration was aim 20% or more of the total platelet plasma volume. The sequestration protocol was three sequestration cycles performed just prior to surgery. The concentrated platelet portion was reinfused after weaning from the cardiopulmonary bypass. Hundred seven parameters/patients were recorded. Sixty patients entered the study; 30 in the PSQ group and 30 controls (CTR). RESULTS: Patient characteristics, operation data, preoperative hematology and coagulation parameters did not differ between the groups. In the PSQ group a mean of 433+/-34 ml concentrated platelet portion was collected. The mean platelet count in the concentrated platelet portion was 749+/-157x10(3)/microl, resulting in a platelet yield of 28+/-6% (2040%). The average total chest tube blood loss was 423 ml (PSQ) compared to 858 ml (CTR), p<0.001. A greater number of CTR patients required blood transfusion postoperatively (23) compared to PSQ (3), P<0.001, and fluid requirements were also significantly increased in the control group, P<0.001. No statistical differences in hematology and coagulation parameters between the groups were observed. The hospital mortality was low and the incidence of postoperative complications was few and without group differences. Post-extubation gas exchange was better in PSQ patients compared to CTR. CONCLUSIONS: A preoperative PSQ of a minimum 20% of the total platelet plasma volume resulted in significantly lower postoperative blood loss and fluid and blood transfusion requirements compared to controls. Post-extubation gas exchange was also better after PSQ. Only one patient did not tolerate the sequestration. No other adverse effects of the procedure were observed.     

Isoflurane preconditioning-induced cardio-protection in patients undergoing coronary artery bypass grafting

BACKGROUND AND OBJECTIVES: Ischaemic preconditioning is commonly regarded as one of the most powerful protective mechanisms against a subsequent lethal ischaemic injury during coronary artery bypass graft surgery but is not practiced routinely. Experimentally, isoflurane, a commonly used volatile anaesthetic agent, provides myocardial protection through a signal transduction cascade that is remarkably similar to the pathways identified in ischaemic preconditioning. The aim of our study was to investigate whether pre-ischaemic administration of isoflurane exerted protection against prolonged ischaemia with functional recovery and reduced necrosis among patients undergoing coronary artery bypass graft surgery. METHODS: Forty patients scheduled for elective coronary artery bypass graft operations were prospectively randomized into the control or isoflurane groups. In the isoflurane group, isoflurane 2.5 minimum alveolar concentration was administered for 15 min followed by a 5-min washout period before aortic cross-clamping. The control group received a time-matched period of isoflurane-free cardiopulmonary bypass. The conduction of anaesthesia and surgery were standardized in all patients. Haemodynamic data, troponin I release and inotropic support were measured and recorded perioperatively. RESULTS: There were no adverse effects related to isoflurane administration. In the isoflurane group, the mean cardiac index after cardiopulmonary bypass was significantly higher than the pre-bypass value (P < 0.05), whereas no difference was found in the control group. At 15 min after cardiopulmonary bypass and 6 h after surgery, the changes in cardiac index and stroke volume index were significantly higher in the isoflurane group than in the control group (P < 0.05). There was a consistently lower release of troponin I in the isoflurane group compared to the control group. Compared to the controls, the mean troponin I level was significantly reduced in the isoflurane group at 24 h after surgery (P = 0.042). CONCLUSIONS: The present results support the preconditioning effect of isoflurane in patients undergoing coronary artery bypass graft surgery as clinically feasible and providing optimal cardiac protection.     

Graft selection in elderly patients undergoing coronary artery bypass grafting

Purpose  

This study aimed to assess the clinical and angiographic outcomes after coronary artery bypass grafting (CABG) in elderly patients (≥75 years).     

Intraaortic balloon pumping in patients undergoing coronary artery bypass grafting

Beneficial effect of preoperative intraaortic balloon pumping (IABP) treatment in high-risk patients who had open heart surgery have been demonstrated. The purpose of this study is to determine the impact of preoperative IABP use on survival in high-risk patients undergoing coronary artery bypass grafting (CABG). METHODS: Two hundred seventy-seven consecutive patients having CABG at our institution were reviewed. Patients having an IABP were identified retrospectively and grouped into one of 3 groups as follows. Group A (n = 14): preoperative IABP for high-risk urgent or elective cases. Group B (n = 26): preoperative IABP for emergency cases. Group C (n = 6): unplanned intraoperative or postoperative IABP. RESULTS: Forty-six patients had an IABP (16.6% of total). Parsonnet score in group B was significantly higher (p < 0.05). Length of operation for group C was significantly longer (p < 0.05). Overall hospital mortality in the total group of 277 cases was 4.2%. Hospital mortality was 7.1% in group A, 7.7% in group B, and 50% in group C. Hospital mortality in group C was significantly higher (p < 0.01). CONCLUSIONS: The beneficial effect of preoperative treatment with IABP in high-risk patients undergoing CABG was confirmed. This approach resulted in a significantly lower hospital mortality.     

Anesthesia in patients undergoing valvular replacement and coronary artery bypass grafting

We investigated the intraoperative hemodynamic changes in patients who underwent combined valvular replacement (VR) and coronary artery bypass grafting (CABG). The data of 8 patients who under went VR + CABG were compared with those of 50 patients who underwent VR during the same period (1986). Heart rate before the institution of cardiopulmonary bypass (CPB) was not different between these two group, but blood pressure of VR + CABG cases was significantly higher than that of VR cases. This required a higher dosage of fentanyl in VR + CABG cases.     

Clopidogrel and bleeding in patients undergoing elective coronary artery bypass grafting

Objective

In an effort to minimize transfusions in patients undergoing elective coronary artery bypass grafting operations after recent clopidogrel exposure, we studied laboratory tests predictive of platelet dysfunction and used a strict algorithm-driven treatment of bleeding.

Methods

Forty-five patients receiving clopidogrel within 6 days of the operation and 45 control subjects were studied. Prothrombin time, activated partial thromboplastin time, platelet count, and platelet function test results were measured before heparinization, after protamine administration, and then every 2 hours. No transfusions were administered unless a patient met both laboratory and clinical criteria.

Results

Algorithm-driven treatment of bleeding significantly reduced the mean units of all blood components transfused by about one third, as shown by comparison with current control and historical data. Compared with current control subjects, clopidogrel recipients required significantly more transfusions of platelets (9.0 ± 1.7 vs 1.2 ± 0.5 U; P < .0001) and packed red blood cells (4.3 ± 0.6 vs 2.3 ± 0.5 U; P = .01) and required longer periods of controlled ventilation (12.4 ± 1.3 vs 8.6 ± 0.8 hours; P = .02). Preoperative platelet dysfunction before heparin administration for cardiopulmonary bypass, as measured by using adenosine diphosphate aggregometry (response <40%), predicted all but 1 case of severe coagulopathy requiring multiple transfusions (16.6 ± 2.8 U of platelets and 5.8 ± 1.0 U of packed red blood cells).

Conclusions

A strict transfusion algorithm can reduce the transfusion requirement for all blood components. Preheparin testing of platelet function with adenosine diphosphate aggregometry can identify patients at highest risk for perioperative bleeding and transfusions and might further reduce the perioperative transfusion requirement.     

Angiographic coronary diffuseness and outcomes in dialysis patients undergoing coronary artery bypass grafting surgery.

OBJECTIVE: Pre-operative dialysis-dependent renal failure (DDRF) is a predictor of morbidity and mortality following coronary artery bypass grafting surgery (CABG). Whether this is due in part to a more diffuse coronary atherosclerotic burden in these patients is unknown. The purpose of this study was to compare coronary atherosclerotic disease burden in patients with and without pre-existing DDRF undergoing CABG. METHODS: From a retrospective analysis of a single-centre cardiac surgical database, consecutive DDRF patients undergoing isolated CABG (n=35) were matched to 70 non-dialysis-dependent (NDD) patients without renal failure by procedure, age, sex, functional status, ejection fraction, number of diseased vessels, and diabetes. Pre-operative angiograms were analyzed by a single, blinded adjudicator using a modification of a previously published coronary diffuseness score (range: 0-45). Angiographic scores and baseline and outcome characteristics were compared using chi(2) tests, Fisher's Exact tests, and t-tests as appropriate. RESULTS: No statistical differences were found among pre-operative characteristics between the two groups. The mean angiographic coronary diffuseness scores for the dialysis and non-dialysis groups were 18.2 and 20.6, respectively (p=0.13). Transfusion was more frequent (77 vs. 23%, p<0.0001) and median length of stay longer (9 vs. 7 days, p=0.02) in the DDRF group. There were no differences in the number of distal anastomoses performed in the two groups. Low rates of peri-operative myocardial infarction, stroke, re-operation, and in-hospital mortality were observed in both groups. CONCLUSIONS: Objective quantification revealed that patients with DDRF undergoing CABG did not have a greater coronary artery atherosclerosis disease burden than matched controls who did not have pre-operative DDRF. This may be due to pre-operative patient selection bias. The increased morbidity and mortality of CABG in patients with DDRF is more likely to be due to the multiple adverse systemic effects of renal failure and dialysis on the cardiovascular system as opposed to diffuseness of distal coronary disease.     

Orthotopic heart transplantation with concurrent aortic valve replacement and coronary artery bypass grafting.

We report a case of successful orthotopic heart transplantation of a donor heart with normal ventricular function, 2-vessel coronary artery disease, and a bicuspid aortic valve, which required concurrent aortic valve replacement and coronary artery bypass grafting. In confronting the disparities in demand and supply, we must consider the so-called marginally acceptable heart for either critically ill recipients or those who may be disadvantaged on the waiting list.     

Beating heart coronary artery bypass grafting

Objectives: We have studied the results of 402 consecutive cases of beating heart coronary artery bypass grafting (CABG) and evaluated the usefulness of gastroepiploic artery (GEA) composite grafts. Methods: Between March 1993 and August 2001, 402 patients underwent beating heart CABG. They were 321 male and 81 female patients, aged 17 to 88 (mean 66) years. Beating heart CABG was facilitated by mechanical stabilization with a doughnut stabilizer, a newly designed sternal retractor and a new coronary perfusion system. Minimally invasive direct coronary artery bypass (MIDCAB) was performed in 206 patients (the MIDCAB Group), and beating heart CABG with median sternotomy (OPCAB) was performed in 196 patients (the OPCAB Group). Results: Definite off-pump CABG was accomplished in 381 patients. 21 patients (5%) were converted to on-pump beating heart CABG using percutaneous cardiopulmonary system via femoral vessels because of hemodynamic instability. There was 1 operative mortality (0.2%). There was perioperative myocardial infarction in 2 (0.5%), and cerebral infarction in 3 (0.7%). The rate of complete revascularization was 78% in the MIDCAB Group and 97% in the OPCAB Group. The mean number of anastomoses was 1.6 in the MIDCAB Group and 3.3 in the OPCAB Group. The early graft patency was 99.1% in a left internal thoracic artery graft, 97.0% in a right internal thoracic artery graft, 96.5% in GEA, 98.2% in a radial artery graft, and 94.2% in a vein graft. A GEA composite graft was used in 55 of the 168 patients who received GEA grafting. The mean number of anastomoses for the GEA composite graft was 1.6±0.6 per patient. The graft patency rate was 94.6% (53/56) for GEA and 98.6% (72/73) for the radial artery used as a composite graft. Conclusion: A consecutive series of beating heart CABG was performed safely and effectively with a low mortality rate and low morbidity rate. Beating heart CABG could be performed in all patients, and definite off-pump CABG was accomplished in 95% of them. In order to aim for complete revascularization, GEA composite graft was found to be effective since it required a low mean number of 1.6 anastomoses and a satisfactory patency rate at the same time. Read at the Fifty-fourth Annual-Meeting of the Japanese Association for Thoracic Surgery, Panel discussion, Osaka, October 3–5, 2001.     

The pharmacokinetics of remifentanil in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Remifentanil is a potent opioid with a short duration of action. It has the potential for large-dose opioid anesthesia without an obligatory prolonged period of mechanical ventilation. However, because of high clearance and rapid tissue distribution, cardiopulmonary bypass (CPB) may influence its pharmacokinetics and alter drug requirements. We administered remifentanil by continuous infusion to 68 patients having coronary artery bypass graft surgery during CPB with hypothermia to describe the effects of these interventions on its pharmacokinetics. Remifentanil concentrations were measured before, during, and after CPB. Disposition was best described by a two-compartment model. The volume of distribution increased by 86% with institution of CPB and remained increased after CPB. Elimination clearance decreased by 6.37% for each degree Celsius decrease from 37 degrees C. IMPLICATIONS: Remifentanil concentrations decrease with the institution of cardiopulmonary bypass because of an increase in the volume of distribution. The decrease in elimination clearance with hypothermia results in increased total remifentanil concentrations during cardiopulmonary bypass if the infusion rate is not altered. More constant blood remifentanil levels may be obtained by reducing remifentanil infusion rate by 30% for each 5 degrees C decrease in temperature.     

非体外循环下冠脉搭桥术的围术期管理

目的：比较非体外循环搭桥术与体外循环搭桥术病人的术中及术后早期恢复情况。方法39例病人接受了非体外循环下冠脉搭桥术,同时期33例病人接受了体外循环冠脉搭桥术。两组均采用中等剂量阿片静脉复合全麻,结果：病人的麻醉时间、手术时间、术后机械通气时间和在监护室的停留时间,非体外循环组明显短于体外循环组（P＜0．01）。围术期平均输血量和血血病人数在1支桥病人中非体外循环组明显少于体外循环组（P＜0．05）。术后房颤发生率和围术期心肌梗死发生率两组间无明显差异,术后脑卒中,低心排及死亡的发生率各组均为0％。结论与外循环搭桥术相比,非体外循环搭桥术缩短了病人的麻醉、手术及在监护室停留时间,加快了病人的恢复、从耐而提高了手术的安全性,并降低了手术费用。     

Preoperative coronary artery bypass grafting in patients undergoing abdominal aortic reconstruction

The effect of preoperative aortocoronary bypass grafting on the operative mortality of patients undergoing elective abdominal aortic reconstruction was examined by reviewing a series of 224 consecutive patients (1980 to 1983) (Group I) in whom selective preoperative noninvasive and invasive cardiac screening was used to identify patients with significant coronary stenoses. One patient died during cardiac catheterization. Twenty-seven patients (12 percent) underwent aortocoronary bypass grafting with one operative death (3.7 percent) and one nonfatal myocardial infarction (3.7 percent). These 26 patients subsequently underwent abdominal aortic reconstruction with no mortality and no postoperative myocardial infarction. One hundred ninety-six patients (88 percent) underwent aortic reconstruction without prior aortocoronary bypass grafting with four operative deaths (2 percent), including two fatal myocardial infarctions. The combined operative mortality for Group I patients was 2.3 percent. Three hundred twenty-six patients (Group II) who underwent abdominal aortic reconstruction at this institution from 1970 to 1976 had an 8 percent operative mortality, of which 50 percent of the deaths were due to myocardial infarctions (Group I versus Group II, p less than 0.01). Selective preoperative screening for coronary artery disease in patients undergoing elective abdominal aortic reconstruction with aortocoronary bypass grafting in selected patients is safe and may help reduce the operative mortality.