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.     

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。     

Quadruple coronary artery bypass grafting.

In our last 150 consecutive revascularization operations, 30 patients (20%) have had 4 or more bypass grafts. One patient died after quadruple grafting (mortality, 3%). Twenty-two (75%) of the survivors have been rehabilitated to active work status and 25 (86%) were considered by their cardiologists to have improved function postoperatively by New York Heart Association criteria. Preoperatively 15 patients (50% of the group) had either a markedly diminished ejection fraction (EF) or extreme elevation in left ventricular end-diastolic pressure (LVEDP) or both. Complete revascularization, with resection of ventricular aneurysms when present, can be carried out successfully in a high-risk group of patients. Elevated LVEDP or diminished EF per se is not a valid contraindication to myocardial revascularization.     

Perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Two patients in whom myocardial infarction in the inferior wall occurred after off-pump coronary artery bypass grafing (OPCAB) are described. In both patients, the right coronary artery had no critical lesion and was not grafted. There was no ischemic episode during operation. Coronary artery spasms and/or intracoronary thrombus formation may have been causes of these events. To our knowledge, this is the first report on perioperative myocardial infarction in OPCAB.     

Perioperative coronary artery spasm in off-pump coronary artery bypass grafting and its possible relation with perioperative hypomagnesemia.

PURPOSE: We experienced 3 cases of serious perioperative coronary artery spasm in off-pump coronary artery bypass grafting (OPCAB). In consideration of the causes, we directed our attention to hypomagnesemia, one of the triggers of coronary artery spasm. This study was performed to confirm the tendency to hypomagnesemia in OPCAB. METHODS: First, we report 3 patients having severe coronary artery spasm immediately after OPCAB with consideration of the causes. Second, serial magnesium (Mg) value (xylidyl blue method, normal 1.9-3.1 mg/dl) was measured in 45 consecutive patients with OPCAB between April and October 2002, 1) before starting the operation, and 2) after the patient's entrance into the intensive care unit. RESULTS: Preoperative and postoperative values of Mg (mg/dl) were 2.1+/-0.3, 1.7+/-0.3, respectively (p < 0.01). Postoperative incidence of hypomagnesemia was as high as 89% of the patients (40 out of 45 patients). In this study and thereafter, we corrected hypomagnesemia with magnesium sulfate during and after OPCAB, and no perioperative coronary artery spasm occurred. CONCLUSION: Hypomagnesemia, one of the triggers of coronary artery spasm, is very common in OPCAB. We strongly recommend the correction of hypomagnesemia during and after OPCAB for the prevention of perioperative coronary artery spasm.     

Robotic coronary artery bypass grafting

Robotically assisted surgery enables coronary surgery to be performed totally or partially endoscopically. Using the Da Vinci robotic technology allows minimally invasive treatments. We report on our experience with coronary artery surgery in our department: patients requiring single or double vessel surgical revascularization were eligible. The procedure was performed without cardiopulmonary bypass on a beating heart. From April 2004 to May 2008, 55 consecutive patients were enrolled in the study, and were operated on by a single surgical team. Operative outcomes included operative time, estimated blood loss, transfusions, ventilation time, intensive care unit (ICU) and hospital length of stay. Average operative time was 270 ± 101 min with an estimated blood loss of 509 ± 328 ml, a postoperative ventilation time of 6 ± 12 h, ICU stay of 52 ± 23 h, and a hospital stay of 7 ± 3 days. Nine patients (16%) were converted to open techniques, and transfusion was required in four patients (7%). Follow-up was complete for all patients up to 1 year. There was one hospital death (1.7%) and two deaths at follow-up. Coronary anastomosis was controlled in 48 patients by either angiogram or computed tomography scan, revealing occlusion or anastomotic stenoses (>50%) in six patients. Overall permeability was 92%. Major adverse events occurred in 12 patients (21%). One-year survival was 96%. Our initial experience with robotically assisted coronary surgery is promising: it avoids sternotomy and with a methodical approach we were able to implement the procedure safely and effectively in our practice, combining minimal mortality with excellent survival.     

非体外循环下冠状动脉旁路移植术

目的 报告微创非体外循环冠状动脉旁路移植术(OPCABG),探讨其手术指征及外科处理要点。方法 回顾性总结5例OPCABG的临床资料。结果 5例顺利完成非体外循环冠状动脉旁路移植术。随访3～4个月,无死亡,无明显心绞痛及心肌缺血表现。结论 对于选择的患者,OPCABG安全、经济、有效,是一种值得推广的微创心脏手术方法。     

Third-time coronary artery bypass grafting

BACKGROUND: In this study we analyze the short- and long-term results, and the clinical, functional, and subjective status of patients after a second coronary reoperation (RE-RE-CABG). METHODS: The perioperative data of 33 consecutive patients undergoing RE-RE-CABG (1987 to 1998) were studied. Follow-up information was obtained from our follow-up databank. A cross-sectional follow-up was conducted, with additional functional evaluation by the Duke Activity Status Index (DASI), and patients' evaluations of their life situation were registered. RESULTS: Perioperative mortality was 2 of 33 patients (6%). During the follow-up (mean 51.6 months) 5 patients died. The 26 survivors showed a significant decrease in New York Heart Association class from 3.6+/-0.4 preoperatively versus 2.2+/-0.6 postoperatively. The mean Duke Activity Status Index score was 29.30+/-16.34 (range 7.22 to 48.9). In all, 18 of 26 patients (70%) were declared to have benefitted from the RE-RECABG. CONCLUSIONS: The significant improve in New York Heart Association class and good postoperative functional capacity, justified the RE-RE-CABG. However, patients must be informed about the limitations of this procedure.     

Redo coronary artery bypass grafting

Purpose

Redo coronary artery bypass grafting (CABG) can be one of the most technically challenging operations in cardiac surgery. The coronary disease is more advanced, and the coronary targets may be suboptimal. In addition, the patients are typically older and sicker compared to those undergoing primary CABG.

Methods

A literature review focused on the epidemiology, operative techniques, and outcomes associated with redo CABG.

Results

The frequency of redo CABG relative to total CABG procedures has been decreasing over time. From 2000 to 2009, redo CABG decreased from 6.0 to 3.4% of all CABG procedures reported to the STS Adult Cardiac Surgery Database (STS ACSD) and currently stands at 2%. Risks associated with reoperations include diabetes and renal dialysis. Perioperative mortality for redo CABG is reported to be as high as three times that of primary CABG, but this risk is reduced with experience. Careful preoperative planning including quality imaging and precise surgical technique coupled with meticulous myocardial protection contributes to good outcomes. Experience is important in optimizing outcomes.

Conclusions

Redo CABG is a complicated operation and surgical experience, and appropriate perioperative strategies are essential for achieving optimal outcomes.

     

Hybrid coronary artery bypass grafting

Owing to the high prevalence of atherosclerotic coronary artery disease, treatment has proceeded along three separate paths: medical, surgical, and percutaneous intervention. Medical treatment is now routinely combined with both surgical treatment and percutaneous methods; however, the surgical and percutaneous routes are often viewed as in competition. Hybrid coronary revascularization, also called robotic assisted integrated coronary revascularization (RAICER), is a way of combining these two approaches. Whether any hybrid procedure will prove beneficial to patients remains unproven; however, RAICER has promise for reducing short-term complications while providing excellent and enduring treatment for coronary artery disease. Much work remains to be done on the benefits of hybrid revascularization in comparison with conventional bypass surgery or percutaneous coronary procedures.     

Redo coronary artery bypass grafting

Objectives: Redo coronary artery bypass grafting (CABG) has been gradually increasing in Japan. We prospectively collected redo-CABG data and evaluated these the early and remote results. Methods: Between 01/01/1994 and 06/30/2002, a total of 71 patients underwent isolated redo-CABG in our hospital group. The interval between operations was 7.8±6.1 years. Previous surgery was CABG in all patients. Perioperative, early angiographic, and follow-up results were analyzed. Results: The mean number of grafts was 2.9±1.2. There were 4 incidences of injury to the heart or graft during sternal re-entry or during dissection of the heart. There was 1 hospital death (2.8%) and 19 major complications (26.8%), including 7 patients (9.9%) with postoperative congestive heart failure and 2 (2.8%) with postoperative myocardial infarction. Postoperative angiography was obtained in 47 patients and their overall stenosis free patency rate was 93.9%. Follow-up was completed for all hospital survivors with a mean follow-up of 3.9±2.2 years. The event-free and survival rates at 5 years were 76.4% and 83.9%, respectively. Conclusion: In our limited experience, redo-CABG was performed with acceptable risks and its long-term results were satisfactory.     

Redo coronary artery bypass grafting

Redo coronary artery bypass grafting (CABG) is more challenging than primary CABG in many aspects. Patients who undergo redo CABG are older, more comorbid, and with more sclerotic coronary and noncardiac arteries than seen in primary CABG. Operative procedures are more complicated, reentry of the sternum is sometimes problematic, and dissection of the heart is needed. If patent vein grafts are diseased, they can be sources of thromboembolism, and the patent left internal thoracic artery (ITA) anastomosed to the left anterior descending artery (LAD) must not be injured. The number of redo CABG procedures has been decreasing, because of frequent use of ITA to the LAD in primary CABG, aggressive percutaneous coronary intervention (PCI) by interventional cardiologists, and optimal medical therapy after primary CABG. In-hospital mortality in redo CABG is two to five times higher than that of primary CABG, although outcomes have been improving in recent years despite the patients’ more comorbid background. Long-term survival after redo CABG is comparable to that of PCI. The indication for redo CABG should be limited to patients who have jeopardized LAD territory, which is viable. CABG is also preferable to PCI in patients with more diseased vein grafts and low cardiac function. Various technical refinements have also improved the surgical results of redo CABG. Retrograde cardioplegia greatly contributed to proper myocardial protection, especially when the occluded coronary arteries are supplied by patent in situ arterial grafts. The off-pump technique has been used in redo CABG and may be beneficial in a selected, more comorbid population.     

Coronary artery spasm after coronary artery bypass grafting.

We report a case of a 62-year-old man with severe manifestations of postoperative coronary artery spasm following effective coronary artery bypass grafting. The coronary artery spasm was manifested by ST segment elevation, hypotension and wall motion abnormalities on echocardiography. Urgent angiography confirmed the diagnosis and intracoronary infusion of nitroglycerine and verapamil relieved the coronary spasm.     

心肌特异性脂肪酸结合蛋白在不停跳冠状动脉搭桥术中的变化

Objective To appraise the sensitivity of hFABP for myocardial ischemia in patients undergoing off-pump coronary artery bypass grafting among cardiac markers. Methods Thirty-eight consecutive patients undergoing OPCABG were included in a randomized study using standardized operative procedures and myocardial protection. Serial blood samples were taken preoperatively, during anastomoses, at the end of operation, 6 h, 18 h and 36 h postoperatively and tested for hFABF,Troponin Ⅰ （cTnⅠ） ,sCD40L,creatine kinase isoenzyme （CK-MB）. Results Six cases （16.7%） were found myocardial injury during the OPCABG by ECG or PAP. Their serial serum hFABP,cTnⅠ,sCD40L, CK-MB were higher than those without myocardial injury. The peak serum level of hFABP was higher and occurred earlier than those of cTnⅠ, sCD40L,CK-MB. Conclusion These results suggest that serum hFABP is an early and sensitive biochemical marker for the diagnosis of myocardial injury in patients undergoing OPCABG.     

非体外循环下冠状动脉旁路移植术

目的 总结110例非体外循环心脏跳动下冠状动脉旁路移植术经验，探讨其手术适应证、优缺点及手术方法。方法 常温、全身麻醉，胸正中切口，非体外循环心脏跳动下，应用特殊心表固定器行冠状动脉旁路移植术，平均搭桥3．9支，血管桥为乳内动脉、大隐静脉及桡动脉。结果 全组无手术死亡，术后心绞痛症状消失。手术时间平均为210min，术后气管插管时间平均为4．8h。术后住院时间平均为10d，住院费用平均为4．4万元。其中3例术中出现不可逆血压过低、室颤而转为体外循环冠状动脉旁路移植术。结论 非体外循环心脏跳动下冠状动脉旁路移植术是一种安全、有效的治疗方法。特别适合于老年及心功能差的患者，可减少体外循环并发症，缩短术后住院时间，降低住院费用，但不能完全替代体外循环旁路移植术。     

Repeat coronary artery bypass grafting

In 1981-1989 we performed repeat coronary artery bypass grafting on 42 men and 10 women (mean age 55 years) with angina pectoris recurring on average 27 months after the primary operation. The cause was occlusion or stenosis of vein grafts alone (59%) or in combination with progression of native coronary atherosclerosis (31%) or progression in the native circulation without graft failure (10%). Complications at the repeat operation included five lesions of the right ventricle and five lesions of patient grafts. The 30-day mortality was 3.8% (95% confidence limits 0.5-13.2%). Survival after observation averaging 2 1/2 years was 92.3% (95% confidence limits 81.5-97.9%). Angina pectoris was completely relieved after the operation in 48% of the patients, lessened in 35% and unchanged in 17%. Although repeat coronary artery bypass grafting carries heightened mortality and morbidity, and the results are less satisfactory than after first-time bypass, the operation can be worthwhile.