Complete thromboendarterectomy of the calcified ascending aorta and aortic arch

Surgical strategies for severely atherosclerotic (porcelain) aorta during coronary artery bypass grafting

Porcelain aorta (PA) is an asymptomatic atherosclerotic disease, characterized by circumferential calcification throughout the whole perimeter of the aorta. It is seen in 2% to 9.3% of patients undergoing elective coronary artery bypass grafting (CABG) and makes manipulation of the ascending aorta impossible. It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping. Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke. The incidence of stroke after CABG is between 0.48% and 2.9%, and the risk is correlated with the extent and severity of the atherosclerotic disease. A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta, application of a cross-clamp to the aorta, and partial clamping of the aorta to create the proximal anastomosis. Therefore in procedures that involve cannulation, clamping, or proximal anastomosis, and where aortic manipulation is inevitable, preassessment of the atherosclerotic aortic plaques is crucial. Although many surgeons still rely on intraoperative manual aortic palpation, this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness. Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis. Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta. Anaortic or "no-touch" techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli. In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta, modifications in the surgical techniques, such as switching to different cannulation sites including the axillary/subclavian, femoral and innominate arteries, or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts, or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.

Aortic endarterectomy: a useful technique to utilize for aortic valve replacements in hostile aorta

Calcified aorta poses a significant technical challenge in the performance of surgical aortic valve replacement (AVR). Aortic endarterectomy is a less utilized approach and is suitable in select cases for aortic decalcification during AVR. Here, we report a case of calcified ascending aorta who underwent ascending aortic endarterectomy and AVR with the technical details of the procedure.

Aortic Arch Endarterectomy Associated with On-Pump Cardiac Surgery in Patients with a Mobile Arch Atheroma

We describe aortic arch endarterectomy performed concomitantly with on-pump cardiac surgery in 2 patients with grade V arch atherosclerosis. In both patients, transesophageal echocardiographic findings led to the diagnosis of severe arch atherosclerosis associated with a mobile atheromatous plaque in the aortic arch. The severe arch atherosclerosis was managed with endarterectomy under deep hypothermic circulatory arrest. In patients with severe grade V atherosclerosis in the aortic arch, performing endarterectomy simultaneously with primary cardiac surgery may be justified as a way to reduce the risk of peripheral embolism, including cerebrovascular accidents, with minimal additional surgical risk.

Bad aorta

As its outcomes improve, cardiac surgery has been performed on more and more cases which were previously considered to be difficult to deal with. However, there are still a number of problems to be solved regarding surgery on patients with severe sclerotic lesions in the ascending aorta, which we collectively call "bad aorta". Concerning a preoperative assessment of the ascending aorta, our report revealed no relationship between the severity of calcification detected with a preoperative non-enhanced CT and the aortic lesion found during the surgery. Meanwhile, an intraoperative epiaortic ultrasound enables us to make high-quality evaluations of the aorta without imposing much burden on the patient. This modality may be essential for cardiac surgery. As for surgical management for bad aorta, quite a few methods have been reported to this point, but the overall operative mortality rate and cerebrovascular accident rate are relatively high, at a little <10 %, respectively. With the recent cross-clamping method under short-term total circulatory arrest (TCA), however, the results are much better; these rates total around 5 %. Further improvement is expected in the outcome of cardiac surgery on bad aorta cases by establishing a modality to evaluate sclerotic lesions in the ascending aorta with epiaortic ultrasound and by selecting a proper procedure for each case.

Occlusive ascending aorta and arch atheroma treated with deep hypothermic circulatory arrest and thromboendarterectomy

We describe an uncommon presentation of severely advanced aortic atherosclerosis in a 48-year old man with a history of hypertension and heavy smoking. Initial presentation with upper limb ischaemia led to the diagnosis of an aortic arch atheroma occluding 90% of the aortic lumen, managed with deep hypothermic circulatory arrest and aortic thromboendarterectomy. To our knowledge, this is the first reported case of atherosclerotic plaque resulting in aortic occlusion and requiring emergent operative intervention.

Current role and outcomes of ascending aortic replacement for severe nonaneurysmal aortic atherosclerosis

BACKGROUND

Severe atherosclerosis of the ascending aorta is a challenging issue potentially affecting indications for surgery, operative choices, and patients' outcome. No standard treatment has emerged to date, and uncertainties persist about criteria for selecting patients and procedures.

METHODS

Replacement of the atherosclerotic ascending aorta was performed in 64 patients at time of either aortic (n = 49), mitral (n = 21), or tricuspid (n = 7) valve surgery. Coronary artery bypass grafting was performed in 53 patients, and the majority of patients underwent combined procedures (n = 49). Mean age was 72.0 +/- 7.6 years. The expected operative mortality, by logistic European System for Cardiac Operative Risk Evaluation, was 29.0% accounting for ascending aortic replacement and 13.1% disregarding it. Circulatory arrest under deep hypothermia, eventually combined with either retrograde or antegrade brain perfusion, was required in 61 cases.

RESULTS

Early death, stroke, and myocardial infarction rates were 10.9%, 6.3%, and 7.8%, respectively. Factors univariately associated with early deaths were preoperative renal failure requiring dialysis (p = 0.001) and longer cardiopulmonary bypass (p = 0.001) and cardioplegia (p = 0.008) times. Cumulative survival at 1, 3, and 5 years was 86% +/- 4%, 74% +/- 6%, and 68% +/- 8%, respectively.

CONCLUSIONS

Replacement of the atherosclerotic ascending aorta can be carried out at acceptable mortality rates despite the high rates of preoperative comorbidity and the significant incidence of postoperative complications.

Meta-analysis of the diagnostic accuracy of transesophageal echocardiography for assessment of atherosclerosis in the ascending aorta in patients undergoing cardiac surgery

BACKGROUND

Stroke after cardiac surgery may be caused by emboli emerging from an atherosclerotic ascending aorta (AA). Epiaortic ultrasound scanning (EUS), the current 'gold' standard for detecting AA atherosclerosis, has not gained widespread use because there is a lack of optimized ultrasound devices, it lengthens the procedure, it endangers sterility, and there is a false belief by many surgeons that palpation is as sensitive as EUS. Furthermore there is no clear evidence proving that the use of epiaortic scanning changes outcome in cardiac surgery. Various researchers investigated the ability of transesophageal echocardiography (TEE) to discriminate between the presence and absence of AA atherosclerosis. It is acknowledged that TEE has limited value in this, but it has never been supported by a meta-analysis estimating the true diagnostic accuracy of TEE based on all quantitative evidence. We aimed to do this using state-of-the-art methodology of diagnostic meta-analyses.

METHODS

We searched multiple databases for studies comparing TEE vs. EUS for detection of atherosclerosis. A random-effects bivariate meta-regression model was used to obtain summary estimates of sensitivity and specificity, incorporating the correlation between sensitivity and specificity as well as covariates to explore heterogeneity across studies.

RESULTS

We extracted six studies with a total of 346 patients, of whom 419 aortic segments were analyzed, including 100 segments with atherosclerosis [median prevalence 25% (range 17-62%)]. Summary estimates of sensitivity and specificity were 21% (95% CI 13-32%) and 99% (96-99%), respectively.

CONCLUSIONS

Because of the low sensitivity of TEE for the detection of AA atherosclerosis, a negative test result requires verification by additional testing using epiaortic scanning. In case of a positive test result, AA atherosclerosis can be considered as present, and less manipulative strategies might be indicated.

Surgical management of the atherosclerotic ascending aorta: is endoaortic balloon occlusion safe?

BACKGROUND

Occlusion of the atherosclerotic ascending aorta by an endoaortic inflatable balloon has been proposed as an alternative to conventional cross-clamping to prevent injury to the vessel and distal embolization of debris. The safety and the effectiveness of endoaortic occlusion have not been documented in this setting.

METHODS

Endoaortic occlusion was employed in 52 of 2,172 consecutive patients. Surgeon's choice was based on preoperative identification of aortic calcifications or intraoperative epiaortic ultrasonographic scanning. Deaths and strokes were analyzed casewise and in aggregate.

RESULTS

In 10 patients (19.2%), the endoaortic balloon had to be replaced by the ordinary cross-clamp because of incomplete occlusion (n = 5), hindered exposure (n = 2), or balloon rupture (n = 3). In-hospital death occurred in 13 patients (25%), and stroke on awakening from anesthesia in 2 (3.8%). The death rate of patients treated by endoaortic occlusion was significantly higher compared with all other patients (4.2%, p < 0.0001) and with the expected estimate by European System for Cardiac Operative Risk Evaluation (10.5%, p = 0.05). By multivariable analysis, use of endoaortic occlusion was independently associated with in-hospital death (odds ratio = 5.609, 95% confidence interval: 2.684 to 11.719). Although the stroke rate was higher in the endoaortic occlusion group compared with all other patients, the difference was only possibly significant (3.8% versus 0.8%, p = 0.067).

CONCLUSIONS

In this series, the endoaortic occlusion was frequently ineffective, and was associated with a significantly higher risk of in-hospital death and a numerically higher risk of stroke.

Endovascular Clamping of Porcelain Aorta in Aortic Valve Surgery using Foley Catheter

Unclampable calcified aorta is an uncommon condition that all cardiac surgeons may encounter and performing aortic valve surgery in this condition with a non cross-clamping technique of using Foley Catheter has rarely been reported. Aortic valve surgery invariably becomes a high-risk, challenging procedure to cardiac surgeon or even a contraindication to surgery when the ascending aorta cannot be clamped due to extensive calcification precluding safe dissection and clamping. We describe and recommend a non cross-clamping technique of using Foley Catheter and report it successful use in two patients who underwent aortic valve replacement with "porcelain" unclampable aorta.

Hypothermic Circulatory Arrest Enables Aortic Valve Replacement in Patients With Unclampable Aorta

BACKGROUND

Atheroembolic complications associated with clamping a severely diseased ascending aorta during aortic valve replacement may result in unacceptable mortality and morbidity. Different management options include hypothermic circulatory arrest to replace the aortic valve, an aortic endarterectomy, or tube graft replacement of the aorta to allow safe application of cross-clamp before aortic valve replacement.

METHODS

From 1998 to 2004, 70 patients who underwent aortic valve replacement had an aorta that was unclampable. Median age was 76 years; 33 (47%) were women; 46 (66%) had concomitant coronary artery bypass grafting; 9 (13%) had concomitant mitral valve surgery; and 4 (6%) were reoperations. Hypothermic circulatory arrest was used to replace the aortic valve alone, to do an aortic endarterectomy, or replace the ascending aorta with a tube graft.

RESULTS

Operative mortality was 4%. There were 8 (11%) strokes and 1 (1.4%) transient ischemic attack. Statistical analysis showed no association between circulatory arrest period and occurrence of adverse cerebral events. There was no significant difference among the three groups when operative mortality and cerebral events were compared.

CONCLUSIONS

Hypothermic circulatory arrest is an important adjunct that allows aortic valve replacement to be performed with an acceptable mortality but with an increased risk of cerebral event in this high-risk and elderly group of patients.

'No touch' techniques for porcelain ascending aorta: comparison between cardiopulmonary bypass with femoral artery cannulation and off-pump myocardial revascularization

BACKGROUND

Detection of severe atherosclerotic ascending aorta during coronary artery bypass grafting requires alterations in the standard surgical technique to reduce the probability of stroke-related atheroembolization. Off-pump coronary artery bypass grafting (OPCAB) confers the benefits of avoiding aortic cannulation and clamping, and may therefore attenuate this risk.

METHODS

OPCAB (n = 41) was compared to cardiopulmonary bypass (CPB) using femoral arterial cannulation and hypothermic fibrillatory arrest (n = 15), in patients with porcelain ascending aorta undergoing myocardial revascularization. In both groups, a 'no touch' technique was applied by avoiding aortic cannulation and clamping. Proximal anastomoses on the atherosclerotic aorta were avoided by arterial grafting, (in-situ or T-graft configurations) in all cases.

RESULTS

Operative mortality was comparable (2.4% and 6.6% in the OPCAB and CPB groups respectively, p = NS). The rate of adverse neurological events, (two strokes and one transient ischemic attack), was higher in the CPB group (p = 0.0164). Based on brain CT, the nature of the recorded stroke suggested retrograde emboli. Three year survival (Kaplan-Meier) for the OPCAB and CPB groups was 86.7% and 81.3%, respectively (p = NS). Occurrence of late neurological adverse events during follow-up (8-51 months) was similar.

CONCLUSIONS

In patients with porcelain ascending aorta undergoing myocardial revascularization, neurological outcome of OPCAB patients is better than CPB using femoral artery cannulation.

Two cases of a free-floating ball thrombus in the left atrium

A free-floating ball thrombus in the left atrium is an unusual occurrence that may cause fatal systemic emboli or left ventricular inflow obstruction, often resulting in sudden death. The first of 2 cases was a 59-year-old female with mitral stenosis and chronic atrial fibrillation who presented with severe dyspnea. Transthoracic echocardiography revealed a free-floating ball thrombus and emergency thrombectomy and mitral valve replacement were performed successfully. A second thrombus, which was not found at preoperative examination, was attached to the anterior mitral leaflet and may have been the source of the free-floating ball thrombus. The second case was a 79-year-old female with chronic renal failure who underwent mitral valve replacement 11 years prior to admission. She had been dependent on hemodialysis for 10 years, and had suffered several recent transient cerebral ischemic attacks. Computed tomography showed a ring-shaped, high-density area in the left atrium and transthoracic echocardiography revealed a floating ball thrombus in the left atrium. Thrombectomy was performed, but the patient died as a result of postoperative pneumonia 2 months later. Case 2 appears to be the first reported case of a ball thrombus in a hemodialysis patient who had previously undergone mitral valve replacement.

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.

The unclampable ascending aorta in coronary artery bypass patients: A surgical challenge of increasing frequency

BACKGROUND

The unclampable ascending aorta (UAA) is a condition increasingly encountered during CABG procedures. We report our experience with CABG patients with UAA and place particular emphasis on the preoperative diagnosis and surgical management.

METHODS AND RESULTS

UAA was diagnosed in 211 of 4812 consecutive CABG patients (4.3%). On the basis of the chest radiograph, echocardiogram, and coronary angiograph, a preoperative diagnosis was achieved in only 58 patients (27.4%). An age of >70 years, diabetes, smoking, unstable angina, diffuse coronaropathy, and peripheral vasculopathy were all predictors of UAA. Patients were treated with hypothermic ventricular fibrillation (no-touch technique n=129) or beating heart revascularization (no-pump technique n=82) depending on the possibility of founding an arterial cannulation site. The overall in-hospital mortality rate was 2.8% (6 of 211) with no differences between the 2 surgical strategies. The no-touch technique was associated with a greater incidence of neurological complications (stroke and transient ischemic attack), renal insufficiency, and stay in the intensive care unit and hospital. However, at midterm follow-up, more patients of the no-pump group had ischemia recurrence.

CONCLUSIONS

A preoperative diagnosis of UAA is achievable only in a minority of patients, which highlights the necessity revising the current diagnostic protocols. The use of the no-touch technique is associated with an high perioperative risk but a superior possibility of complete revascularization, whereas adoption of the no-pump strategy ensures a smoother postoperative course at the expense of an higher incidence of ischemia recurrence.

Aortic valve replacement for the calcified ascending aorta in homozygous familial hypercholesterolemia

A 72-year-old woman who had been diagnosed as homozygous familial hypercholesterolemia was admitted for chest discomfort. Computed tomography and cardiac catheterization revealed severe calcification of the aortic root and a high grade stenosis of the proximal right coronary artery. Aortic valve replacement concomitant with coronary artery bypass was done using temporary hypothermic circulatory arrest. This is preferred method when dealing the calcified aorta.