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.     

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。     

Coronary bypass grafting with totally calcified or acutely dissected ascending aorta

From August 1984 through November 1988, 10 of 2,658 patients undergoing coronary artery bypass grafting had ascending aortic disease that was not amenable to proximal anastomoses for coronary bypass grafting. This was due to a calcified aorta in 6 and acute aortic dissection in 4. There were 5 male and 5 female patients with a mean age of 71 years. Cannulation site was the femoral artery in 5, ascending aorta in 3, and aortic arch in 2. Profound hypothermia and ventricular fibrillation, with no cross-clamp or cardioplegia, was used in 9 patients, and circulatory arrest in 1. In 8 patients a single internal mammary artery was used as the total inflow with a saphenous vein graft brought off the internal mammary artery to one or more distal left-sided coronary vessels. Bilateral internal mammary arteries were used in 2 other patients. Operative mortality was zero. There was one perioperative myocardial infarction and one transient stroke without sequelae. All patients have done well from 1 to 6 years postoperatively. These data support the use of internal mammary arteries as single or bilateral proximal conduits for other venoarterial bypass grafts when the aorta is extensively diseased either by calcification or dissection.     

Coronary revascularization using an internal mammary artery-saphenous vein composite graft in a patient with severely calcified ascending aorta

A 52-year-old woman with angina pectoris resulted from complete obstruction of left coronary ostium required double-vessel bypass. Because of severely calcified ascending aorta, avoidance of aortic cross-clamping was needed for the prevention of embolic injury and aortic dissection. Internal mammary artery (IMA)-saphenous vein (SV) composite graft under hypothermic ventricular fibrillation was successfully performed without any complication. IMA-SV composite graft is a good alternative in a case of insufficient IMA length and limited site for proximal vein graft anastomosis, which can avoid or reduce the manipulation of diseased ascending aorta.     

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.     

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.     

Clinical experience with aortic connector system

From April to December 2002, 40 patients underwent coronary artery bypass grafting (CABG) using the St. Jude Medical (Minneapolis) Symmetry bypass system (aortic connector system: ACS). 59 proximal anastomoses (51 saphenous vein grafts, 8 radial artery grafts) were performed with the ACS. One saphenous vein graft occluded during operation. Postoperative evaluation of the anastomotic patency was carried out by angiography in 45 grafts. Five of the saphenous vein grafts were occluded (5/38). One patient who was shock state before operation presented with postoperative unconsciousness. Another patient died at 8th postoperative day caused by ventricular fibrillation. We conclude that the ACS produces a simple, quick way of performing the proximal anastomosis without the need for clamping the aorta, allows reducing risk of embolization by aortic manipulation. However, it is necessary to discuss sufficiently using the ACS, because the graft patency with the ACS is lower than with standard suturing technique.     

Does routine use of aortic ultrasonography decrease the stroke rate in coronary artery bypass surgery?

Purpose: The purpose of this study is to determine whether the routine use of intraoperative surface aortic ultrasonography decreases the stroke rate in coronary artery bypass graft surgery (CABG).Methods: One hundred ninety-five consecutive patients undergoing CABG between July 1, 1992, and June 30, 1993 (study group), were evaluated by intraoperative surface aortic ultrasonography. Based on information obtained, changes in the operative technique were made in an effort to decrease the incidence of embolic stroke from unsuspected atherosclerotic disease of the ascending aorta. The outcome of these patients was compared with that of 164 consecutive patients who underwent CABG between July 1, 1991, and June 30, 1992 (control group), in whom the ascending aorta was assessed by inspection and palpation only.Results: Significant disease was detected in three (2.0%) of 164 patients in the control group. Modifications in their operative technique consisted of hypothermic fibrillatory arrest with no cross-clamping of the aorta and left ventricular venting in two patients and single cross-clamping in one patient. There were five strokes overall in this group (3.0%), and six patients died (3.6%), one in whom the stroke contributed directly to the cause of death. In the study group the ultrasonic findings were normal to mild in 168 patients, moderate in 20 patients, and severe in seven patients. These results led to a modification of the technique in 19 patients, (10%): hypothermic fibrillatory arrest with no cross-clamping of the aorta and left ventricular venting in 14 patients, modification in the aortic cannulation site or single cross-clamping in three patients, and modification in placement of proximal anastomoses or all arterial grafts in two patients. No strokes occurred in this group ( p < 0.02, Fisher's exact test). Five patients died, for an operative mortality rate of 2.6%.Conclusion: These data indicate that intraoperative ultrasonography of the ascending aorta with simple modifications in operative technique reduces the stroke rate in CABG. (J V ASC S URG 1995;21:98-109.)     

Acute type A aortic dissection, developed shortly after aortic valve replacement and coronary artery bypass grafting

We experienced a case of acute type A aortic dissection shortly after a cardiac operation. A 73-year-old man underwent aortic valve replacement and coronary artery bypass grafting for aortic regurgitation and angina pectoris. Aortic valve was tricuspid and the ascending aorta was mildly dilated in preoperative studies. The postoperative computed tomography (CT) revealed aortic dissection, from the ascending aorta to the arch of aorta, although the patient was asymptomatic. Reoperation for the aortic dissection was performed on the 22nd post operative day. Re-do sternotomy was safely carried out prior to heparinization. Under hypothermic circulatory arrest with femoral arterial and venous cannulations, the ascending aorta was replaced and re-implantation of the saphenous vein graft was carried out. The postoperative recovery was uneventful and he was discharged on the 17th postoperative day.     

Endarterectomy and graft replacement of severely calcified (porcelain) ascending aorta with coronary ostial involvement in a patient requiring aortic valve replacement.

We report a successful aortic valve replacement within an extensively calcified (porcelain) aorta, involving the left coronary artery ostium. Clamping such an aorta can result in embolization, dissection, and mural laceration. A 72-year-old female presented with a severely calcified and stenotic aortic valve with a peak pressure gradient of 101 mmHg. Computed tomography demonstrated extensive calcification of the ascending aorta. Coronary angiogram showed a 50% ostial left coronary artery stenosis. Under deep hypothermic circulatory arrest, the aorta was transected at the proximal arch and distal graft anastomosis was performed. This was followed by endarterectomy of the porcelain ascending aorta and the left coronary ostium. Aortic valve replacement, proximal aortic graft anastomosis, and a coronary artery bypass grafting (CABG) with the left internal thoracic artery (LITA) anastomosed to the left anterior descending artery (LAD) were then performed in a sequential manner.     

An alternative technique of proximal anastomosis in patients with an atherosclerotic ascending aorta

Coronary artery bypass grafting operations in patients with an atherosclerotic ascending aorta are still associated with an increased risk of cerebral embolism and mortality despite previously described techniques. Here we present an alternative technique for the construction of a proximal anastomosis avoiding aortic clamping and deep hypothermic circulatory arrest.     

Surgical treatment of valvular and supravalvular aortic stenosis in homozygous familial hypercholesterolemia

A 61-year-old male with homozygous familial hypercholesterolemia presented with dyspnea and syncope. He had been treated with low-density lipoprotein apheresis for 26 years. Echocardiography and computed tomography showed severe valvular and supravalvular aortic stenosis. Computed tomography and cardiac catheterization revealed a severely calcified narrowed aortic root and an occlusion in the proximal right coronary artery. During surgery, the ascending aorta was replaced under deep hypothermic circulatory arrest without aortic cross-clamping. After that, the aortic root from the annulus to the sino-tubular junction was enlarged with a two-ply bovine pericardial patch. An aortic valve replacement with a 17 mm mechanical valve and coronary artery bypass grafting to the right coronary artery were performed. The patient recovered from the surgery without any cerebrovascular complications.     

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.     

Punch-hole aneurysm of the ascending aorta after coronary artery bypass surgery

This report describes the case of a 60-year-old man, who developed a giant punch-hole aneurysm of the ascending aorta five month after uncomplicated coronary artery bypass grafting (CABG) due to a localized rupture of the ascending aorta. The patient underwent surgical repair with cardiopulmonary bypass. Because the false aneurysm was adherent to the sternum, resternotomy was performed in deep hypothermia and circulatory arrest. The lesion in the ascending aorta was closed by means of a dacron-patch. The postoperative course of the patient was completely uneventful. We recommend to repair a false aneurysm of the ascending aorta in deep hypothermic circulatory arrest (DHCA) in order to avoid excessive blood loss during sternotomy.     

The atherosclerotic aorta at aortic valve replacement: surgical strategies and results

BACKGROUND: Aortic valve replacement in patients with severe atherosclerosis of the ascending aorta poses technical challenges. The purpose of this study was to examine operative strategies and results of aortic valve replacement in patients with a severely atherosclerotic ascending aorta that could not be safely crossclamped.Patients and methods: From January 1990 to December 1998, 4983 patients had aortic valve surgery; of these, 62 (1.2%) patients had a severely atherosclerotic ascending aorta and required hypothermic circulatory arrest to facilitate aortic valve replacement. They form the study group. RESULTS: All patients had hypothermic circulatory arrest, but several different strategies were used to manage the ascending aorta. These techniques included aortic valve replacement with the use of hypothermic circulatory arrest (39%), ascending aortic endarterectomy (26%), ascending aortic replacement (19%), aortic inspection and crossclamping during hypothermic circulatory arrest (10%), and balloon occlusion of the ascending aorta (6%). Duration of hypothermic circulatory arrest was substantially longer for patients having aortic valve replacement with hypothermic circulatory arrest than for all other strategies. Hospital mortality was 14%, and 10% of patients had strokes. Increasing New York Heart Association functional class and impaired left ventricular function were risk factors for hospital mortality. Choice of operative technique did not influence patient outcome; however, no patient who underwent replacement of the ascending aorta had a stroke. CONCLUSIONS: Aortic valve replacement in patients with severe atherosclerosis of the ascending aorta is associated with increased operative morbidity and mortality. Complete aortic valve replacement during hypothermic circulatory arrest, the "no-touch" technique, requires a prolonged period of circulatory arrest. Ascending aortic replacement is a preferred technique, as it requires a short period of hypothermic circulatory arrest and results in comparable mortality with a low risk of stroke.     

On-pump beating-heart mitral valve plasty without aortic cross-clamping

Patients with ischemic cardiomyopathy often have mitral regurgitation, which should be corrected for better long-term survival. Mitral valve surgery is usually performed during cardiopulmonary bypass under the arrested heart condition. The ascending aorta is cross-clamped and the heart is arrested using a cardioplegic solution. However, because ischemic cardiomyopathy patients often have a severely atherosclerotic ascending aorta and low cardiac function, aortic cross-clamping and cardiac arrest increase the risk of postoperative thromboemboli and low cardiac output syndrome. Under the on-pump beating-heart condition, we performed mitral valve plasty concomitant with coronary artery bypass grafting, tricuspid annuloplasty, left ventricular aneurysmectomy, and the maze procedure without aortic cross-clamping for a patient with ischemic dilated cardiomyopathy and bradycardial atrial fibrillation. The patient had no postoperative complications and recovered rapidly. Thus, to prevent serious postoperative complications, on-pump beating-heart mitral valve surgery without aortic cross-clamping may be a suitable surgical option for patients with ischemic cardiomyopathy.     

Influence of Potassium Cardioplegia versus Ischemic Arrest on Regional Left Ventricular Diastolic Compliance in Humans

To compare the effects of hypothermic ischemic arrest versus hypothermic potassium cardioplegia, regional left ventricular performance was monitored in 20 adult male patients undergoing saphenous vein bypass operation. Twelve patients received ischemic arrest (Group 1), and 8 received potassium cardioplegia (Group 2). Groups 1 and 2 did not differ in left ventricular ejection fraction (0.62 versus 0.60), number of bypassed vessels (3.7 versus 3.4), mean cross-clamp time (75 versus 63 minutes), or mean cardiopulmonary bypass time (182 versus 170 minutes). Before cardiopulmonary bypass was begun, a pair of ultrasonic crystals was secured in the left ventricular anterior myocardium to measure segment motion and a micromanometer-tipped catheter was placed in the left ventricular chamber. All patients received a saphenous vein bypass graft to a vessel supplying the anterior left ventricular wall in the region of the ultrasonic crystals.Comparison of changes in systolic measurements revealed no significant differences between Groups 1 and 2. After saphenous vein bypass grafting, the left ventricular end-diastolic pressure (11.4 to 17.0 mm Hg) and modulus of left ventricular segment stiffness (0.37 to 0.67, p < 0.02) were elevated in Group 1 but no changes were observed in Group 2 (14.0 to 15.6 mm Hg, and 0.16 to 0.24, respectively).Compared with hypothermic ischemic arrest, hypothermic potassium cardioplegia is not associated with an increased left ventricular diastolic stiffness shortly after saphenous vein bypass grafting in humans.     

Hypothermic circulatory arrest does not increase the risk of ascending thoracic aortic aneurysm resection.

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of a period of deep hypothermic circulatory arrest (DHCA) during elective replacement of the ascending thoracic aorta. SUMMARY BACKGROUND DATA: DHCA has been implemented in ascending thoracic aortic aneurysm resection whenever the anatomy or pathology of the aorta or arch vessels prevents safe or adequate cross-clamping. Profound hypothermia and retrograde cerebral perfusion have been shown to be neurologically protective during ascending aortic replacement under circulatory arrest. METHODS: The authors conducted a retrospective analysis of 91 consecutive patients who underwent repair of chronic ascending thoracic aortic aneurysms from 1986 to present. The authors hypothesized that patients undergoing DHCA with or without retrograde cerebral perfusion during aneurysm repair were at no greater operative risk than patients who received aneurysm resection while on standard cardiopulmonary bypass. RESULTS: There were no significant differences in hospital mortality, stroke rate, or operative morbidity between patients repaired on DHCA when compared to those repaired on cardiopulmonary bypass. CONCLUSIONS: DHCA with or without retrograde cerebral perfusion does not result in increased morbidity or mortality during the resection of ascending thoracic aortic aneurysms. In fact, this technique may prevent damage to the arch vessels in select cases and avoid the possible complications associated with cross-clamping a friable or atherosclerotic aorta.     

Antegrade selective cerebral perfusion during surgery of the thoracic aorta: risk analysis

Objective: To determine independent predictors of neurologic outcome and hospital mortality after surgery of the thoracic aorta using moderate hypothermic circulatory arrest and antegrade selective cerebral perfusion. Methods: Between November 1996 and June 2000, 96 consecutive patients (69 men, 27 women; mean age 63±10 years) underwent operations on the thoracic aorta with the aid of moderate hypothermic circulatory arrest and antegrade selective cerebral perfusion. Sixty-four patients were operated on electively (66.7%), 32 emergently (33.3%). Indications for surgery were: type A acute dissection in 30 patients (31.3%), chronic aneurysm in 66 (68.8%). Seventeen patients (17.7%) had undergone previous aortic/cardiac surgical procedures. The mean selective cerebral perfusion time was 52.2±31.9 min (range, 18–220 min). Preoperative, intraoperative, and postoperative factors were analyzed by univariate and multivariate analysis to identify predictors of hospital mortality and neurologic outcome. Results: There were no operative deaths; the hospital mortality rate was 11.5% (11/96). Stepwise logistic regression revealed preoperative renal dysfunction (P=0.021), type A acute dissection (P=0.053), coronary artery bypass grafting (P=0.058), post-operative pulmonary complications (P=0.000) and repeat thoracotomy for bleeding (P=0.027) as independent predictors of hospital mortality. One patient sustained a permanent neurologic deficit (1%). Transient neurologic deficit occurred in eight patients (8.3%). Coronary artery bypass grafting (P=0.013), and postoperative cardiac complications (P=0.049) were statistically associated with an increased risk of any (transient and permanent) neurologic dysfunction on univariate analysis. Stepwise logistic regression indicated coronary artery bypass grafting as independent factor for any neurologic dysfunction. Conclusion: This study confirmed that selective cerebral perfusion is an effective method of cerebral protection allowing complex thoracic aorta operations to be performed with low risk of hospital mortality and adverse neurologic outcome. We didn't find that the duration of selective cerebral perfusion time influence hospital mortality and any neurologic deficit.     

Outcome of thoracoabdominal aortic operations using deep hypothermia and distal exsanguination

BACKGROUND: Operation of the descending and thoracoabdominal aorta may be affected by a significant perioperative morbidity, mainly because of ischemic damage of the spinal cord and malperfusion of the abdominal organs. METHODS: A comparative analysis was performed on two consecutive series of patients operated between 1982 and 1998. Group 1 consisted of 90 patients operated with moderate hypothermic left heart bypass. Group 2 included 38 patients operated using deep hypothermic cardiopulmonary bypass and a period of circulatory arrest while performing the proximal anastomosis and distal exsanguination during confection of the distal anastomosis. RESULTS: Main demographic factors and causes of the aortic disease were similar in both groups. Early mortality was significantly higher in the group of patients with aortic cross-clamping (15 of 90, 16%) than in those operated with circulatory arrest (2 of 38, 5.2%), p < 0.001. Paraplegia occurred in 8 patients in the group operated with mild hypothermia (8.8%) but in only 1 patient (2.6%) when deep hypothermia had been used. CONCLUSIONS: In our experience, deep hypothermia combined with distal exsanguination significantly improved the early postoperative outcome after operation of the descending and thoracoabdominal aorta. This technique allowed easy confection of proximal and distal anastomoses, and the duration of the operation was not prolonged significantly through this approach.