升主动脉粥样硬化患者的冠状动脉旁路移植

目的 总结冠状动脉粥样硬化性心脏病合并升主动脉粥样硬化患者冠状动脉旁路移植手术的特点。方法 22例患者中,13例采用非体外循环、心脏不停跳下冠状动脉旁路移植术(59％);9例采用低温体外循环(41％),其中5例在深低温、低流量并间断停循环条件下不阻断升主动脉行旁路-升主动脉近端吻合。结果 20例康复出院,术后早期死亡2例;并发症有肺部感染、心绞痛、室颤、急性心肌梗死和血胸,无神经系统并发症。结论 减少术中升主动脉操作是防止升主动脉损伤和减少并发症的关键。应用带蒂动脉旁路、旁路远端序贯吻合和近端Y形吻合可避免或减少旁路-升主动脉吻合;低温体外循环加左心室引流时,可不阻断升主动脉行旁路远端吻合;深低温、低流量并间断停循环下行旁路-升主动脉吻合,可避免阻断和部分阻断升主动脉,利于控制并发症。     

Extra-anatomic coronary artery bypass graftings in patients with porcelain aorta

AIM: Severely atherosclerotic (porcelain) ascending aorta is associated with increased morbidity and mortality during coronary artery bypass grafting (CABG) due to the increased risk of perioperative atheroembolism. Three maneuvers during CABG can cause atheromatous embolism from the diseased ascending aorta: 1) cannulation of the ascending aorta; 2) cross- clamping; 3) partial clamping for the construction of the proximal anastomosis. METHODS: In our hospital, extra-anatomic CABG was performed in 8 patients with heavily calcified ascending aorta: 6 patients were men and 2 women. Operations were performed on the beating heart in 5 patients, 2 patients operated on beating heart and another patient on fibrillating heart with supportive cardiopulmonary bypass (CPB). Arterial cannulation was done through the right femoral artery on these patients. Apart from internal mammary artery (IMA) grafts, proximal anastomotic sites were the right axillary, right subclavian and innominate arteries. RESULTS: One patient who preoperatively had dialysis dependent chronic renal failure, died as a result of dialysis complication on the 5th day. The postoperative course was uneventful in the other patients and no patient experienced either any cerebrovascular or visceral organ injury as a result of atheroemboli. CONCLUSION: We think that extra-anatomic CABG procedures are safe and reliable in patients with severely atherosclerotic (porcelain) ascending aorta to minimize the prevalence of perioperative stroke and systemic embolization.     

Patency of saphenous vein coronary artery bypass grafts from the vascular prosthesis of the ascending aorta.

BACKGROUND: Patients who have Stanford type A aortic dissection with impaired coronary arteries or who have aneurysms from the ascending aorta to the aortic arch with coronary artery disease need coronary artery bypass grafting (CABG) with tube graft replacement of the ascending aorta simultaneously. When vein grafts are used for CABG in these patients, the proximal anastomoses of vein grafts are attached to the prosthetic tube graft of the ascending aorta. However, the validity of proximal anastomoses of vein grafts to the prosthetic tube graft of the ascending aorta has not been confirmed. PATIENTS AND METHODS: We retrospectively analyzed patients who underwent venous coronary bypass grafting with prosthetic graft replacement of the ascending aorta. Between January 1984 and October 2002, 35 patients underwent CABG using saphenous vein grafts at the time of tube graft replacement of the ascending aorta, and the proximal anastomoses of the vein grafts were attached to the tube graft of the ascending aorta. Thirty-three venous bypass grafts were analyzed in 24 survivors. RESULTS: The postoperative catheterization showed only one early vein graft occlusion of 16 vein grafts anastomosed distally to the left anterior descending artery (LAD). All 14 venous grafts anastomosed to the right coronary artery (RCA) and 3 to the left circumflex artery (LCX) were patent. Therefore, the postoperative patency rate at discharge was 97.0% (32/33). Spiral computed tomography performed for long term follow-up revealed occlusion of two vein grafts (3.5 years and 9.7 years) anastomosed to the LAD. CONCLUSIONS: The patency rate of vein grafts anastomosed from prosthetic grafts of the ascending aorta to the native coronary arteries was similar to that of conventional CABG using saphenous vein grafts.     

Pressure characteristics in arterial grafts for coronary bypass surgery

The haemodynamic properties of arterial grafts were studied by measuring the pressure waveform at the tip of the grafts in 28 patients who underwent coronary artery bypass surgery (CABG). The internal thoracic and gastroepiploic arteries were harvested as pedicles for CABG. Pressure wave of the ascending aorta and arterial grafts were simultaneously recorded with an electrocardiogram under stable haemodynamic conditions before cardiopulmonary bypass. Systolic, diastotic and mean pressures were measured, and mean systolic and diastolic pressures calculated for systolic and diastolic areas divided by time. The ascending aorta showed high sustained diastolic pressure that decreased gradually. Pressures in the internal thoracic and gastroepiploic artery grafts had narrow contours and decreased rapidly. Pressure waveforms in the internal thoracic and gastroepiploic artery grafts had a notch between the systolic and diastolic contours. There was no difference in systolic pressure between the ascending aorta and internal thoracic and gastroepiploic artery grafts. Diastolic pressures were 64(9), 55(7), and 51(6) mmHg in the ascending aorta and internal thoracic and gastroepiploic artery, respectively. Mean(s.d.) pressures were 75(9), 65(9) and 59(7) mmHg in the ascending aorta and internal thoracic and gastroepiploic artery grafts, respectively. Diastolic and mean pressures in the internal thoracic artery grafts were significantly lower than in the ascending aorta but significantly higher than in the gastroepiploic artery grafts. The mean(s.d.) calculated diastolic pressure in the internal thoracic artery grafts was significantly lower than in the ascending aorta but significantly higher than in the gastroepiploic artery grafts. The inferior capacity of flow through the arterial grafts may be mainly attributable to reduced diastolic pressure, which is caused by anatomical characteristics. Arterial grafts originating from a systolic-dominant circulation far away from the heart have a limited ability to supply blood to the diastolic-dominant coronary circulation.     

On-pump beating coronary artery bypass grafting with axillary cannulation in the presence of atherosclerotic lesions in the ascending aorta

A 72-year-old man was admitted to our hospital for dyspnea and chest pain. Coronary artery bypass grafting (CABG) was scheduled because of severe stenosis of the left main trunk. Computed tomography showed severe atherosclerotic lesions in the whole aorta, especially in the ascending aorta. Although off-pump CABG was thought to be the 1st choice, we determined that it would be difficult to establish a cardiac support device due to atherosclerotic lesions in case of sudden deterioration. We performed on-pump beating CABG with axillary cannulation with an 8 mm tube graft. Postoperatively, we recognized no symptoms of stroke, and the patient was discharged on the 12th postoperative day. Axillary cannulation using a side graft was useful in the presence of atherosclerotic lesions in the ascending aorta.     

Bi-directional single anastomotic technique for the proximal anastomosis of free grafts (the saphenous vein or radial artery) to the ascending aorta in coronary artery bypass grafting surgery.

In an operation involving coronary bypass grafting, anastomoses to the ascending aorta with saphenous vein or radial artery grafts may increase the possibility of post-operative strokes by the dislodgement of embolic particles into the arterial vasculature. We report a bi-directional single anastomotic technique to decrease the possibility of intra and postoperative strokes and to allow earlier cardiac perfusion by the graft anastomosed to the ascending aorta, in case of CABG with 2 free grafts from there.     

Combined aortic valve replacement and coronary artery bypass grafting with in situ arterial grafts for porcelain aorta.

Patients with porcelain aorta carry a high risk of cerebral as well as systemic embolism during cardiac surgery. Here we describe a case of severe aortic stenosis and coronary artery disease combined with the circumferentially calcified aorta. The patient was a 77-year-old man who successfully received four coronary artery bypass grafts with in situ arterial grafts without clamping the aorta and aortic valve replacement. Aortic valve replacement and two distal coronary artery anastomoses to the left circumflex artery and obtuse marginal branch were performed under cardiac arrest during hypothermic perfusion with endoaortic balloon occlusion, followed by partial endarterectomy and closure of the aorta buttressed with bovine pericardium under deep hypothermic circulatory arrest. While rewarming, the other two distal coronary anastomoses to the left anterior descending artery and diagonal branch were done on the beating heart in order to minimize cardiac arrest time. On-pump beating heart coronary artery bypass grafting (CABG) can be useful especially for combined complex cardiac surgery.     

An evaluation of coronary artery bypass grafting without aortic cross-clamping due to severely atherosclerotic ascending aorta

OBJECTIVES: We evaluated coronary artery bypass grafting (CABG) in which aortic cross-clamping is not done due to severe atherosclerosis of the ascending aorta. METHODS: Subjects were 51 patients undergoing CABG without aortic cross-clamping during cardiopulmonary bypass under moderately hypothermic ventricular fibrillation in the 12 years from June 1988 to October 1999 (Group N). In some cases, empty beating or moderate hypothermic circulatory arrest was used. We compared these 51 with 1104 subjects undergoing conventional CABG with aortic cross-clamping and cardioplegic cardiac arrest in the 9 years from June 1988 to December 1997 (Group A). RESULTS: In all 6 cases with neurologic deficits, moderately hypothermic circulatory arrest was used during proximal anastomosis of saphenous vein grafts. Postoperative computed tomography scan showed them to have suffered infarction due to embolization. Multivariate analysis identified proximal saphenous vein grafting under moderately hypothermic circulatory arrest as a predictor of neurologic deficit. Complete revascularization was significantly lower in Group N. Actual survival and freedom from cardiac death were significantly lower in Group N. CONCLUSION: Manipulation of the atherosclerotic ascending aorta under moderately hypothermic circulatory arrest or ventricular fibrillation generates the highest risk of perioperative neurologic deficit and should thus be avoided. In-situ arterial grafting should be conducted with utmost care.     

Coronary artery bypass grafting for ischemic heart disease combined with aortitis

Coronary artery bypass grafting (CABG) was performed in a 67-year-old woman with aortitis. She had a past history of right radical mastectomy. Preoperative coronary angiogram showed diffuse stenotic lesions in both right and left coronary arteries. The pressure gradient between ascending aorta and peripheral radial artery was 90 mmHg and the cause of coronary stenosis seemed to be hypertension due to stenotic distal aorta. The aortogram showed occluded bilateral internal thoracic arteries (ITA) and stenotic abdominal aorta. The cephalic artery was supplied by a large meandering artery via dilated gastroepiploic artery (GEA). And thus the GEA was not useful for CABG. Quadruple CABG was performed with mild varicose saphenous vein (saphenous vein grafts to left anterior descending artery and third branch, and sequential saphenous vein graft to right posterior descending and atrioventricular branches). It seemed to be important to demonstrate the arterial lesion of ITA and GEA before CABG in patients with aortitis.     

Bovine internal thoracic artery graft. Successful use at urgent coronary bypass surgery

Bovine internal thoracic artery grafts (Bioflow) were successfully utilized in two patients for emergency coronary artery bypass grafting (CABG). One patient was an 80-year-old man with severe varicose veins and a calcified ascending aorta. Heart failure occurred after triple CABG with bilateral internal thoracic and gastroepiploic arteries. The addition of a Bioflow graft to the circumflex artery restored good cardiac function. The second case was a 54-year-old man whose patent old saphenous vein graft was accidentally injured at reoperation. Emergency use of the Bioflow to bypass the right coronary artery in combination with the right gastroepiploic artery graft to the anterior descending artery resulted in an excellent outcome. The two Bioflow grafts were patent at the 20th and 10th postoperative days, respectively. These cases strongly suggest the efficacy of Bioflow during emergency situations in CABG.     

Off-pump coronary bypass using interposed radial artery graft

We describe a patient with severely diseased ascending aorta and small internal mammary arteries, who underwent off-pump coronary artery bypass to the left anterior descending coronary artery and right coronary artery using composite arterial grafts consisting of the pedicled proximal internal mammary artery and interposed radial artery graft. The interposed radial artery graft provides advantages, such as making coronary anastomosis on the beating heart easier and to increasing the flow potentiality of the internal mammary artery.     

Strategies for preventing stroke after coronary artery bypass grafting

To evaluate the usefulness of our strategy for preventing stroke after CABG, 343 consecutive patients were investigated retrospectively. Patient ages ranged from 32 to 31 years (mean; 63 ± 9 years). There were 254 males and 59 females. Number of grafts per patient was 1 to 5 (mean 2.4 ± 0.9 grafts). In 193 patients, internal carotid arteries (ICAs) were preoperatively evaluated by duplex scanning or cerebral angiogram. The degree of atherosclerosis in the ascending aorta was preoperatively examined by plain computed tomography in 181 patients, during surgery by ultrasonography in 75 patients and palpation in all patients. Results: 1. On preoperative examination, there were 26 patients (15.1%) with ICA stenosis greater than 50% and 15 patients (7.8%) with stenosis greater than 75%. Six patients had bilateral ICA stenosis or occlusion greater than 75%. In 26 patients with ICA stenosis greater than 50%, history of stroke was significantly more prevalent than that in 167 patients without ICA stenosis (12 patients: 46.2% vs 22 patients: 13.1%, p<0.001). In patients with ICA stenosis greater than 75%, 6 patients were symptomatic and 8 were asymptomatic. For these patients, concomitant carotid endarterectomy and CABG were performed in 5, two stage procedures in 7 reconstruction of cerebral perfusion followed by CABG; 4, followed by CEA: 3), and CABG alone in 3. There was no stroke in any of these patients. 2. Atherosclerosis of the ascending aorta was found in 69 of 343 patients (20.1%). In these patients, single clamp technique was applied in 50 patients, aortic no touch technique in 12 and CABG without cardiopulmonary bypass in one. The arterial cannulation site was changed to femoral artery in 15 and to axillary artery in 6 patients. Statistical analysis indicated that age (older than 60 years) and history of stroke were significant risk factors for atherosclerotic ascending aorta. 3. There were 3 patients (0.9%) with perioperative stroke caused by embolism from the ascending aorta in one and hypoperfusion of the brain during cardiopulmonary bypass in two. Conclusion: Proper treatment of atherosclerotic ascending aorta and carotid occlusion may reduce the incidence of stroke in CABG patients.     

Redo-OPCAB via left thoracotomy using symmetry aortic connector system: a report of two cases

Left thoracotomy is an established approach for redo coronary artery bypass grafting (CABG). This approach has also been successfully used in off-pump coronary artery bypass (OPCAB). Traditionally, the grafts have been anastomosed proximally to the descending thoracic aorta or the left subclavian artery. Recently, proximal connectors have been introduced by various manufacturers for use on ascending aorta during primary CABG and OPCAB. One such device is the Symmetry aortic connector system (St. Jude Medical, Minneapolis, MN). These devices have obviated the need for partial occluding clamps for the construction of the proximal anastomoses and hence are extremely useful when the aorta is heavily calcified. We used this device successfully in two patients undergoing redo-OPCAB, where the proximal anastomosis was constructed on the descending aorta. In so doing, we also used the shortest possible length of vein graft since the descending aorta at that level was much closer than the left subclavian artery. This can be an additional factor in redo-operations where the availability of vein can be an issue.     

Handsewn proximal anastomoses onto the ascending aorta through a small left thoracotomy during minimally invasive multivessel coronary artery bypass grafting: a stepwise approach to safety and reproducibility

Minimally invasive coronary artery bypass grafting (MICS CABG) is a nonrobotic, nonthoracoscopic operation that achieves complete anatomical graft similarity with conventional CABG, while avoiding sternotomy and cardiac anoxia. We describe the stepwise approach to perform proximal anastomoses directly off the ascending aorta and also early results of this operation. All myocardial territories are accessed via a 4- to 6-cm left fifth intercostal thoracotomy. After takedown of the left internal thoracic artery, the ascending aorta is progressively brought into view by the following maneuvers: (1) administration of cardiac inotropes to minimize right ventricle filling, (2) increase in right lung positive end-expiratory pressures and tidal volumes, (3) placement of multilevel pericardial retractions, (4) leftward displacement of the ascending aorta with a gauze anterior to the superior vena cava, and (5) left posteroinferior displacement of the right ventricular outflow tract with an epicardial stabilizer. Handsewn proximal anastomoses can then be performed on the ascending aorta with a side-biting clamp. In the first 100 patients who underwent multivessel MICS CABG with proximal anastomoses directly off the aorta, the mean age was 62.6 ± 10.2 years, and median operative time was 3.5 hours. The mean number of grafts was 2.3 ± 0.5, and there were 3 conversions to open sternotomy. There were no preoperative deaths, 2 reoperations for bleeding, and 2 superficial wound infections. The median length of hospital stay was 4 days. MICS CABG is a safe alternative to conventional CABG, with excellent short-term results.     

Coronary artery bypass grafting by utilizing the artery grafts and bovine internal thoracic artery graft (Bioflow in an elderly patient)]

We performed coronary artery bypass grafting (CABG) in a 80-year-old male with calcified ascending aorta and severe varicose veins utilizing the bilateral internal thoracic arteries and the right gastroepiploic artery under fibrillatory arrest without aortic cross-clamp (aortic no-touch technique). After triple coronary artery bypass grafting was completed, heart failure occurred. Additional Bioflow graft to the circumflex artery restored good cardiac function. The aortic no-touch technique is a useful method for CABG in patients with severe calcified ascending aorta. This experience suggests that the Bioflow graft is a helpful conduit at an urgent situation in CABG.     

Combined aortic valve replacement and coronary artery bypass grafting for a calcified ascending aorta

Although a severely calcified ascending aorta is encountered infrequently, it presents formidable problems during cardiac surgery. We describe a case of severe aortic valve stenosis and coronary artery disease combined with a severely calcified ascending aorta. The patient was an 80-year-old man with a calcified ascending aorta. He successfully underwent an aortic valve replacement and a single coronary artery bypass graft (CABG) using a saphenous vein graft with the proximal end connected on a Dacron patch, which was used for aortoplasty of the calcified plate along the aortotomy. These procedures were performed under moderate hypothermia with aortic clamping. This patch aortoplasty can be a useful alternative in cases that require aortotomy and proximal anastomoses of a CABG on a calcified ascending aorta.     

A case report of coronary artery bypass grafting using hypothermic circulatory arrest technique for the severely calcified ascending aorta]

Severe calcification of the ascending aorta makes coronary artery bypass grafting (CABG) complicated since aortic cross-clamping may induce cerebral embolization of aortic debris or aortic dissection. Furthermore, there are problems that the distal aortic occlusion becomes incomplete and proximal anastomosis between the ascending aorta and saphenous veins becomes impossible. CABG for a 56 year-old male with severely calcified ascending aorta was successfully conducted using hypothermic circulatory arrest technique. His right internal thoracic artery was bypassed to LAD under fibrillatory arrest and then his right gastroepiploic artery was bypassed to the distal portion of RCA under hypothermic circulatory arrest. There was no complication and left ventricular ejection fraction improved from 16% to 38% postoperatively.     

Anesthetic management of patients undergoing coronary artery bypass grafting with the use of an axial flow pump and a short-acting beta-blocker.

OBJECTIVES: To describe the clinical protocol regarding monitoring, pharmacologic interventions, and postoperative care during and after coronary artery bypass grafting (CABG) on the beating heart with an axial flow pump and a short-acting beta-blocker. DESIGN: A retrospective study. SETTING: A university hospital. PARTICIPANTS: Seventeen patients scheduled for elective CABG. INTERVENTIONS: Invasive monitoring was performed with either a standard pulmonary artery catheter (PAC) or a surgically placed PAC. An axial flow pump was inserted through a graft sutured to the ascending aorta. A short-acting beta-blocker was administered to decrease the motion of the heart and make conditions for CABG adequate and safe. MEASUREMENTS AND MAIN RESULTS: Compared with baseline measurements, there were significant decreases in mean arterial blood pressure, mixed venous oxygen saturation, and right ventricular ejection fraction during maximal axial flow pump support and beta-blockade. No significant change in heart rate was observed at this time. Hemodynamic variables were normalized in the intensive care unit. All patients were separated from the Hemopump without inotropic support, and values of troponin-T, aspartate aminotransferase, and alanine aminotransferase were low postoperatively. All patients survived and were discharged from the hospital. CONCLUSION: The anesthetic protocol for patients undergoing surgery with a beating heart and the combined use of an axial flow pump and a short-acting beta-blocker is outlined. Multiple-vessel CABG on the beating heart was performed with maintenance of an acceptable hemodynamic situation.     

Off-pump coronary artery revascularization: ideal indication for patients with porcelain aorta and calcification of great vessels

Patients with porcelain aorta and severe calcification of the great vessels are a challenging dilemma for the cardiovascular surgeon regarding bypass technique, choice of conduit, and selection of proximal anastomotic sites due to the high incidence of devastating thromboembolization and aortic injury. No currently proposed surgical approach avoids manipulation of the heavily calcified ascending aorta. Three patients presented with unstable angina and decreased ventricular function secondary to significant left main coronary artery stenosis and 3-vessel coronary artery disease. In addition to the coronary artery disease, severely calcified ascending aorta and great vessels were discovered. One patient presented with near total distal abdominal aortic occlusion, severe peripheral vascular disease, history of stroke, and carotid endarterectomy. Surgical coronary revascularization was indicated. Coronary artery bypass grafting using internal thoracic artery and greater saphenous vein composite arterial inflow grafts in combination with off-pump beating heart surgery was successfully used. Cardiopulmonary bypass and clamping of the aorta was avoided. No new neurologic deficit was observed. Coronary revascularization with internal thoracic artery composite grafts and avoiding cardiopulmonary bypass and clamping the calcified aorta is an effective method to prevent clamp injury and thromboembolization. Off-pump coronary artery bypass grafting seems to be an ideal indication in patients with porcelain aorta because the surgical techniques of "no-touch" and "no-cannulation" can be applied.     

Type A dissection caused by aortic cannulation during coronary artery bypass grafting; report of a case

A 71-year-old woman who had severe stenosis in the origin of the left anterior descending coronary artery with large diagonal branch was scheduled for coronary artery bypass grafting (CABG). After harvesting of bypass conduits, aortic cannulation was performed into the ascending aorta. Immediately after insertion of the cannula, however, the ascending aorta changed to a bluish color. Epiaortic ultrasonography revealed aortic dissection. Replacement of the ascending aorta was carried out using circulatory arrest under deep hypothermia. The intimal tear was located at the cannulation site. After this procedure, scheduled CABG the left internal thoracic artery to the left anterior descending coronary artery and the saphenous vein graft to the diagonal branch was performed. The proximal site of the saphenous vein graft was anastomosed to the replaced graft. The postoperative course was uneventful. Rapid identification and appropriate surgical management are necessary to minimize patient morbidity and mortality.