Coronary artery bypass grafting without cardiopulmonary bypass: MIDCAB and OPCAB

Minimally invasive direct coronary artery bypass grafting via left anterior small thoracotomy (MIDCAB) and coronary artery bypass grafting without cardiopulmonary bypass (OPCAGB) are accepted technique as less invasive than conventional coronary artery bypass grafting (CABG). We reported our experience with these procedures. From 1996 to December 1999, 176 patients underwent MIDCAB or OPCAB with the internal thoracic artery. The left internal thoracic arteries were used for grafting of the left anterior descending artery (LAD) in 131 patients, LAD and diagonal branches sequentially in 8 patients, using free radial artery conduits for grafting of the right coronary artery (RAC) or left circumflex (LCx) in 7 patients, using radial artery conduits as Y-graft from LAD for grafting of the RAC or LCx in 24 patients, and bilateral internal thoracic artery grafting was performed in 4 patients. One patient (0.6%) died in the hospital. One patient (0.6%) had perioperative myocardial infarction. No patient had cerebrovascular accident and sever wood infection. One-hundred-seventy-four patients (98.8%) had resolution of their angina symptom.     

Coronary vasospasm during off-pump coronary artery bypass grafting; report of two cases

Coronary vasospasm is one of the most dangerous and fatal complications of coronary artery bypass grafting (CABG) operation. Our experiences in recent 2 cases happened during off-pump CABG (OPCAB) are presented. Case 1: A 63-year-old male who had 3 vessels disease underwent OPCAB using left internal thoracic artery (LITA) and the radial artery. When the sternotomy was going to be closed, ST elevation of electrocardiogram (ECG) occurred and was followed by ventricular fibrillation. Intra-aortic balloon pumping (IABP) and percutaneous cardiopulmonary support (PCPS) were applied immediately and an additional grafting to first diagonal artery (D 1) was carried out using a saphenous vein. Case 2: A 67-year-old male underwent OPCAB using LITA and the radial artery. ST elevation of ECG suddenly occurred and was followed by complete atrio-ventricular (AV) block when the sternum was closed. IABP and the ventricular pacing were applied immediately. While OPCAB may be less invasive operating method than conventional CABG, we should pay more attention to the coronary vasospasm.     

Effects of coronary artery bypass grafting on cellular immunity with or without cardiopulmonary bypass: changes in lymphocytes subsets

Cell-mediated immunity responses decrease after all kinds of surgical procedures. Either anesthesia or surgical trauma plays an important role in this effect. Identification of functional lymphocyte subsets, by using appropriate monoclonal antibodies and analysis of flow cytometry data, appears to provide an accurate measurement of cellular immune competence. We found a significant decrease in the total number of T helper/inducer cells (p<0.035), B cells (p<0.043) and natural killer cells (NK) (p<0.018) but in contrast, increase in NK cell activity (p<0.012) in the peripheral arterial blood of ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (group 1) immediately after surgery and postoperative day 1 (POD1). On the other hand, there was no significant change of these parameters occurred in the peripheral arterial blood of ten patients (group 2) who were undergoing coronary artery bypass grafting without cardiopulmonary bypass. Therefore, we conclude that coronary artery bypass grafting (CABG) with cardiopulmonary bypass induce a greater decrease in immunologic response than CABG without cardiopulmonary bypass (off pump) operations. Nevertheless, off pump CABG operations do not induce a greater decrease in immunologic response than other surgical operations.     

Atrial fibrillation after coronary artery bypass grafting without cardiopulmonary bypass.

OBJECTIVE: Atrial fibrillation is the most common complication after heart surgery. It rarely has a fatal outcome but causes patient instability, prolongs hospital stay, or even is the reason for perioperative infarction. Although conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass has excellent short-term and long-term results, the number of coronary operations on a beating heart without cardiopulmonary bypass is still growing. To reduce surgical trauma, off-pump coronary artery bypass grafting via sternotomy (OPCABG) or minimally invasive direct vision coronary artery bypass grafting (MIDCABG) via small thoracotomy are performed. The aim of this study was to estimate the frequency of atrial fibrillation in patients after myocardial revascularization without cardiopulmonary bypass. METHODS: A retrospective analysis of 48 patients undergoing myocardial revascularization without cardiopulmonary bypass was performed. Twenty-four patients underwent OPCABG and 24 were operated using the MIDCABG technique. The incidence of cardiac arrhythmias was analyzed since operation to the fourth postoperative day. Each patient had continuous ECG monitoring with option of arrhythmia analysis during ICU stay. After discharge from ICU 24-h ECG monitor studies were carried out. Surface 12-lead ECG was accomplished once a day, and additionally each time symptoms of cardiac arrhythmia occurred. Risk factors of atrial fibrillation were estimated. RESULTS: Atrial fibrillation occurred in 25% of patients after MIDCABG, in 29% after OPCABG, and in 18% after CABG with cardiopulmonary bypass. This difference has no statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups. CONCLUSIONS: Atrial fibrillation is a common complication after procedures of myocardial revascularization, performed with or without cardiopulmonary bypass. The occurrence is not dependent on the type of operation.     

A randomized, double-blind, placebo-controlled trial of a COX-2 inhibitor (Rofecoxib) in patients undergoing coronary artery bypass surgery

The endothelium of patients with coronary artery disease shows increased expression of cyclooxygenase-2 (COX-2) during coronary artery bypass graft surgery (CABG) using cardiopulmonary bypass. This, together with serotonin, may lead to coronary microvessel spasm, which potentially, can contribute to myocardial ischemia and injury after surgery. We performed a randomized, double-blind, placebo-controlled trial in patients undergoing isolated CABG to determine whether short-term treatment with a selective COX-2 inhibitor, Rofecoxib (25 mg), given preoperatively and for 5 days after operation, can offer better myocardial protection in patients undergoing CABG by measuring serial cardiac troponin T (cTnT) levels. The study was powered to recruit 150 consecutive patients undergoing isolated CABG but the study was terminated prematurely by the worldwide withdrawal of rofecoxib. There were highly statistically significant (P<0.001) increases in cTnT in both groups at each time point (1, 6, 24 and 48 h after onset of cardiopulmonary bypass) compared to preoperative levels. cTnT levels were similar at all post-operative time points between the 2 groups. There is no evidence that short-term treatment with rofecoxib has a myocardial protective effect in patients undergoing CABG. There is also no evidence that its effect is deleterious to the myocardium in patients undergoing CABG.     

冠状动脉旁路移植术后早期紧急再次手术

目的 探讨冠状动脉旁路移植(CABG)术后围术期急性心肌缺血的病因和外科治疗.方法 2001年1月至2009年1月,28例CABG术后早期进行了紧急再次手术.其中男18例,女10例.平均年龄54岁.主要病因包括早期移植物栓塞、乳内动脉(IMA)异常、靶血管吻合口异常,桡动脉(RA)痉挛、心肌血管化不完全.首次手术到再次手术时间间隔1～48 h,平均8 h.紧急再次手术中仅2例选择非体外循环不停跳手术,余均在体外循环心脏停跳下CABG.再次手术包括:对异常移植物尽可能去除,选择重新吻合或远端加一旁路血管.对RA持续痉挛者拆除后用静脉再次行旁路手术.再次手术中给予充分再血管化.结果 手术死亡2例.术后1～14天死亡8例.16例术后放置主动脉内球囊反搏(IABP)辅助,其中2例同时进行体外膜式氧合器(ECMO)辅助,2例同时选择左心辅助装置(LVAD).18例生存者均无严重并发症.结论 CABG术后早期急性严重心肌缺血病死率高.早期诊断和及时外科处理可以提高生存率.强调术前、术后预防的重要性.

Abstract：

Objective To explore the cause of acute myocardial ischemia early after coronary artery bapass graft (CABG) and surgical management on it. Methods From 2001 to 2009, 28 patients underwent urgent reoperation early after CABG due to acute myocardial ischemia. The incidence of reoperation is about 0.02%. The cause of reoperation inclouded early graft occlusion (10 cases) ,IMA damage or injury during harvesting(9 cases), inexactitude distal anastomosis(2 cases)and radial artery spasm(4 cases). The mean interval time between two operations was 8 hours. Reoperation was done under offpump bypass in 2 patients and on-bypass used in other patients. Unsatisfactoey graft were substituted with new graft material and thrombotic was removed. If LIMA was the reson for myocardial ischemia, an additional vein graft was inserted. The spasm radial artery were substituted with new vein graft. Completely revascularization was used in re-do CABG. Results Two patients died during reoperation. 8 patients was died between 1 day and 14 days after reoperation. IABP was used in 16 patients,which 2 patients received ECMO suppord and 2 patient received LVAD suppord at mean time. Conclusion There have very high mortality in acute myocardial ischemia early after CABG. The early diagnosis and correct surgical management can improve the rates of survival. The active prevent should be emphasized during the first CABG.     

The correlation between flow pattern during cardiopulmonary bypass and patency of the coronary artery bypass grafts

Recently the availability of transit time flow measurement (TTFM) is reported especially in off-pump coronary artery bypass grafting (CABG). But little is known about TTFM findings in on-pump CABG. We examined the correlation between the TTFM flow pattern and the angiography findings in on-pump CABG. The subjects consisted of 52 patients who underwent on-pump CABG and angiography early after operation. In these patients, 55 internal thoracic artery (ITA), 17 gastroepiploic artery (GEA), 13 saphenous vein graft (SVG) and 41 radial artery (RA) were tested with TTFM during cardiopulmonary bypass (CPB). TTFM demonstrated a diastolic filling pattern in 53 ITA, 16 GEA, 13 SVG and 36 RA. The angiography revealed that all these grafts were perfectly patent with the exception of a GEA with a flow competition pattern. TTFM revealed an abnormal flow pattern in 2 ITA (these 2 grafts were revised during CPB and the angiography demonstrated their perfect patency), 1 GEA (to and fro pattern), 0 SVG and 5 RA (the abnormal pattern was due to graft spasm in 3 of 5, and the angiography revealed their perfect patency, however, the angiography detected stenosis in the remaining 2 grafts). The present study found that the TTFM flow pattern during CPB correlated well with the angiography findings. TTFM during CPB was useful to detect graft failure, and grafts were revised safely during CPB.     

Coronary artery spasm during coronary artery bypass surgery]

We report two cases of coronary artery spasm during coronary artery bypass surgery. As one of the complications during cardiac surgeries, coronary vasoconstriction occurs mainly after coming off cardiopulmonary bypass. The factors responsible for the spasm include high endogenous catecholamine levels due to inadequate anesthesia and hypothermia, exogenous catecholamines for circulatory support, various chemical mediators and combination of these factors. Coronary artery spasm was suspected strongly because of sudden ischemic change in electrocardiography and simultaneous aggravation of circulatory parameters, which improved immediately after direct injection of coronary vasodilators into vein graft. This method, popular in coronary angiography and catheterization, is effective for release of coronary-artery spasm observed particularly after cardiopulmonary bypass. Then mechanical circulatory assist is readily available to treat possible systemic side effect of the vasodilators.     

Effects of intra-coronary and intra-graft administration of nicorandil for coronary spasm after coronary artery bypass grafting

Coronary artery spasm after coronary artery bypass grafting (CABG) is relatively rare, but when it occurs, it is fatal. In cases of circulatory collapse just after surgery, coronary spasm should be suspected, and immediate diagnosis by coronary angiography is necessary. We conducted a study to assess the clinical characteristics of coronary spasm after CABG and the usefulness of intra-coronary and intra-graft administration of nicorandil. Study subjects were 7 patients (6 men and 1 woman, mean age 60.4 years) in whom coronary spasm after CABG was diagnosed angiographically from January 1992 to December 2003. Off-pump CABG (OPCAB) had been performed in 2 patients. Despite continuous administration of nitroglycerin and diltiazem hydrochloride during surgery, sudden circulatory collapse occurred during surgery or within 24 hours after CABG in all 7 patients. All required mechanical circulatory support, and emergency coronary angiography revealed severe graft and native coronary spasms. Intracoronary and/or intra-graft administration of diltiazem hydrochloride or nitroglycerin was not very effective, however, administration of nicorandil was effective for vasodilatation. One patient suffered brain damage and died, but the other 6 patients recovered and were discharged without complication. In conclusion, intra-coronary and/or intra-graft administration of nicorandil appears to be useful for the treatment of coronary spasm after CABG.     

Coronary artery bypass grafting for dialysis patients

OBJECTIVE: To assess the efficacy and safety of cardiopulmonary bypass during coronary artery bypass grafting (CABG) in dialysis patients. METHODS AND RESULTS: Sixty four isolated CABG patients who underwent on cardiopulmonary bypass and whose intraoperative body weight gains were accurately measured were studied retrospectively. The mean intraoperative body weight gain was 2.61 +/- 0.9 kg/m2 in the study group and 1.06 +/- 0.6 kg/m2 in controls, i.e.) 100 patients selected at random from CABG patients during the same period using cardiopulmonary bypass without chronic renal faulure, showing a statistically significant difference. Complete revascularization was successful in 98% of patients. Postoperative nonlethal complications involved brain infarction in 1 patient (1.7%), reintubation in 1 (1.7%), and paralytic ileus in 2 (3.4%). All were successfully extubated within 24 hours of surgery, and no sternal wound complications were found. Hospital mortality was 6.3% (4/64). Actuarial survival rates at 3, 5 and 8 years including all deaths were 90%, 70% and 56%, and estimated by cardiac deaths were 95%, 90%, and 90% respectively. Cardiac event free rates were 90%, 73% and 61% at 3, 5 and 8 years after CABG. CONCLUSIONS: In CABG for dialysis patients, the use of cardiopulmonary bypass demonstrates significant merits, and may expect long-term survival with minimal postoperative complications.     

Coronary artery spasm after off-pump coronary artery bypass grafting

BACKGROUND: Coronary artery spasm (CAS) in the immediate postoperative period has been recognized as a possible cause for perioperative myocardial ischaemia after off-pump coronary artery bypass grafting (CABG). It varies in severity and can be associated with circulatory collapse and death. The purpose of this study was to present our experiences on CAS after off-pump CABG and detail its management. METHODS: The case reports of three patients with similar clinical presentations of ischaemic heart disease who underwent CABG using an off-pump technique are reviewed. Severe manifestations of CAS in the immediate postoperative period with documented angiographic findings are presented. RESULTS: Three patients (two men and one woman) with angina pectoris were diagnosed with coronary artery disease using coronary angiography. The elective off-pump CABG was uneventful; however, severe manifestation of myocardial ischaemia with abrupt onset developed at the intensive care unit. All three patients underwent immediate coronary angiography to verify the diagnosis of CAS. Apart from intracoronary nitroglycerine infusion and medical support with inotropic agents, extracorporeal membranous oxygenation was carried out because of severe haemodynamic deterioration in one case, while support was required with intraaortic balloon pumping in another. All three patients made a full recovery. CONCLUSION: Coronary artery spasm can severely complicate the postoperative course for patients undergoing off-pump CABG, leading to myocardial ischaemia or infarction, life-threatening arrhythmias, persistent hypotension and even cardiac arrest. Early awareness and diagnosis of CAS with the establishment of appropriate management strategies may prevent its potentially lethal consequences.     

The radial artery for coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularisation, compared with internal mammary artery grafts. Recently, the use of radial artery for CABG has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent reports of encouraging mid-term and long-term patency rates of the radial artery, supports its continued use as a bypass conduit. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.     

On/off-pump beating coronary artery bypass grafting after thoracoplasty

Off-pump coronary artery bypass grafting (CABG) [OPCAB] or on-pump beating CABG (conventional CABG) was performed in 3 post-thoracoplasty patients. Considering their poor respiratory function after thoracoplasty, OPCAB is considered more suitable than conventional CABG with cardio-pulmonary bypass in such cases with severe coronary lesions. However, because the sternum inclines or the pleural cavity may be polluted in these patients, special care is necessary for the operation. In such cases, it may be impossible to bypass to the circumflex artery in OPCAB, and is necessary to consider the use of percutaneous cardiopulmonary support (PCPS), cardio-pulmonary bypass or hybrid therapy before the operation.     

Human cytokine responses to coronary artery bypass grafting with and without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with a systemic inflammatory response. This has been attributed to cytokine release caused by extracorporeal circulation and myocardial ischemia. This study compares the inflammatory response after CABG with cardiopulmonary bypass and after minimally invasive direct coronary artery bypass grafting (MIDCABG) without cardiopulmonary bypass. METHODS: Cytokine release and complement activation (interleukin-6 and interleukin-8, soluble tumor necrosis factor receptors 1 and 2, complement factor C3a, and C1 esterase inhibitor) were determined in 24 patients before and after CABG or MIDCABG. The maximum body temperature, chest drainage, and fluid balance were recorded for 24 hours after operation. RESULTS: Release of interleukin-6, interleukin-8, and tumor necrosis factor receptors 1 and 2 was significantly higher (p < or = 0.005) in the CABG group than the MIDCABG group just after operation. After 24 hours, a significant increase in interleukin-6 was also found in the MIDCABG group (p = 0.001) compared with preoperative value. Body temperature and fluid balance were significantly higher after CABG (p < or = 0.001). CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting represents a less traumatizing technique of surgical revascularization. The reduction in the inflammatory response may be advantageous for patients with a high degree of comorbidity.     

Coronary bypass surgery using arterial conduit and its pitfall]

Three patients with spasm of internal mammary arteries and gastroepiploic artery immediately after coronary bypass surgery were reported. On completion of the revascularization, all patients could not be weaned from cardiopulmonary bypass. The flow velocity waveforms of the arterial grafts measured by pulsed Doppler velocimeter showed only small systolic component without diastolic flow and the palpation revealed profound spasm partially in the arterial conduits. Although all patients could be weaned from cardiopulmonary bypass only after insertion of a saphenous vein graft, two of them died on the next day. In all patients, free flow measured prior bypass was considered to be sufficient and a technically satisfactory anastomosis was felt to be performed. If a profound hemodynamic instability as a result of intractable spasm of arterial conduit occurred after completion of coronary bypass surgery, an additional saphenous vein graft should be placed before discontinuation of cardiopulmonary bypass.     

Combining off pump coronary artery bypass with mitral valve replacement

Background Conventional approach to combined coronary artery bypass grafting (CABG) and mitral valve replacement (MVR) is associated with longer cardiopulmonary bypass (CPB) and aortic cross clamp (ACC) time leading to high operative risk. Methods We conducted a retrospective review of nine consecutive patients undergoing coronary artery bypass grafting/mitral valve replacement combining the off pump technique with cardioplegic arrest. Elective intra aortic balloon pump (IABP) support was instituted in all cases. CABG was first done in all cases without cardiopulmonary bypass support. Mitral valve replacement was then done using conventional cardiopulmonary bypass and cardioplegic arrest using the superior septal approach. Results Nine consecutive patients underwent coronary artery bypass grafting with mitral valve replacement including three patients with acute myocardial infarction. Preoperative echocardiogram revealed a mean ejection fraction (EF) of 38.4 ± 6.0%. Intra aortic balloon pump was inserted in all patients preoperatively. The average number of grafts were 3.0 ± 0.7. Eight patients received bioprosthetic valve while one patient received mechanical prosthesis. The average length of stay in intensive care unit was 3.3 ± 0.5 days. There was no mortality. One patient had superficial wound infection. Conclusion The data suggest that the combined technique (off pump coronary artery bypass grafting and conventional mitral valve replacement) is a safe method to perform coronary artery bypass grafting/mitral valve replacement with minimal morbidity and mortality.     

冠状动脉旁路移植手术围术期血清肌钙蛋白T水平的变化

目的 探讨肌钙旧白Ｔ作为心肌损伤生化樗物的价值。方法 连续选择冠状动脉旁路移植手术（ＣＡＢＧ）患者２２例，分别于麻醉前、体外循环（ＣＰＢ）前、ＣＰＢ结束后即刻和ＣＰＢ后２４小时，抽取静脉血４ｍｌ，用于肌酸激酶（ＣＫ）、肌酸激酶－ＭＢ（ＣＫ－ＭＢ）和心肌肌钙蛋白Ｔ（ｃＴｎＴ）的测定。结果 ＣＰＢ前ＣＫ、ＣＫ－ＭＢ和ｃＴｎＴ的中位数皆在正常范围内，ＣＰＢ后即刻和２４均显著性增高，ＣＫ以术后２４小时最为     

Off-pump CABG for a patient with a brain tumor.

Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG) was performed on a patient with a brain tumor. A patient with effort angina of the left anterior descending artery (LAD), and diagonal branch stenosis was referred to us for CABG. He had a mass lesion in the brain that was diagnosed as meningioma involving the internal carotid artery and a middle cerebral artery. To avoid brain complications, we performed off-pump CABG using the internal thoracic and radial arteries to the LAD and a diagonal branch. Off-pump CABG was an effective method to avoid brain complications for patients with a brain tumor involving cerebral vessels.     

内窥镜采集桡动脉在冠状动脉旁路移植术中的应用及组织学评估

目的 观察冠状动脉旁路移植术(CABG)术中应用内窥镜桡动脉采集技术的效果,通过组织学观察评价内窥镜采集桡动脉的安全性.方法 2003年8月至2008年6月,87例CABG患者采用VagoView5内窥镜系统采集桡动脉.分别对各10例传统切开及内窥镜采集的桡动脉近端和远端各取4 mill,利用光学显微镜和透射电子显微镜检查进行组织学对照.结果 内窥镜采集耗时42～98 min,平均耗时(57.6±17.3)min;获取桡动脉长度15～20 cm,平均(17.5±1.6)cm;采集的桡动脉无明显损伤,除2例外所有采集的桡动脉都被用于CABG.7例患者术后早期拇指背侧有轻度感觉异常,随访3个月后明显改善.光镜和电子显微镜下桡动脉内膜、中层、外膜的损伤情况与传统切开组相似.结论 CABG术中应用内窥镜采集桡动脉可取得良好的外观效果,不损伤桡动脉血管结构,神经损伤可减到最小程度.组织学分析结果证实该方法与传统切开法具有同样的安全性.     

Coronary artery bypass surgery without cardiopulmonary bypass

In the years 1994 and 1995, 1087 patients underwent coronary artery bypass grafting at our institution. Of these, 297 were operated on without cardiopulmonary bypass. 239 were male, and 58 were female. Their ages ranged from 28 to 81 years (54.43 ± 9.63). Of the total, 294 were operated on electively, two as a coronary reoperations, and one as an emergency after a failed percutaneous transluminal coronary angioplasty procedure. In all patients complete revascularization was the aim, and a cardiopulmonary bypass team was kept on standby. Median sternotomy was performed as the exposure in all patients, except a patient who underwent a coronary reoperation through a left thoracotomy incision. The average of the distal anastomoses was 1.51 ± 0.6, ranging from 1 to 3. The left internal thoracic artery was used in 292 operations, which was an individual graft in 284, a sequential graft in five, and a free graft in four. Major complications in the early postoperative period were noted in three patients as reoperation for excessive bleeding. One patient had reoperation for left internal thoracic artery spasm, and one patient had lower extremity ischemia caused by intraoartic balloon counterpulsation. Hospital mortality was 0.3% with one patient. It is our belief that in selected cases coronary artery bypass grafting without cardiopulmonary bypass is a safe procedure with the advantage of improvement in recovery during the postoperative period.