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

The brain-before-heart strategy for coronary artery bypass grafting in the severely atherosclerotic aorta: A single-institution experience

BACKGROUND

Severe atherosclerosis of the ascending aorta (SAA) in patients undergoing surgical revascularization by coronary artery bypass grafting (CABG) is becoming an increasing problem as more elderly patients are diagnosed with coronary artery disease. Strokes and other neurologic insults are common complications in this group, with devastating impacts on outcomes and prognoses.

HYPOTHESIS

Early detection of the atherosclerotic aorta and the application of a stroke prevention protocol will reduce the risk of stroke in patients with SAA.

METHODS

In 2012, we adopted a protocol devised to preemptively detect and manage patients suspected of having SAA. From the time of the application of the protocol, we compared the immediate and late outcomes of CABG in SAA in the 8 years preceding the protocol in a "control" group (30 patients) and in the 8 years following the protocol in a "brain" group (69 patients).

RESULTS

More patients with SAA were detected after the initiation of the protocol. They had significantly more history of stroke, renal dysfunction, and left main coronary disease. The percutaneous coronary intervention was utilized more after the protocol (26% vs. 7%) and there was far less utilization of replacement of the ascending aorta (12% vs. 37%). Postoperative stroke rates were significantly less after the protocol (2% vs. 18%), with an almost twofold reduction in stroke associated with SAA even after risk adjustment. The composite endpoints of cardiac death, nonfatal myocardial infarction, and stroke were significantly reduced after initiating the protocol at a median of 2.3 years from the time of revascularization.

CONCLUSION

Early detection of SAA and individualized therapeutic strategies for revascularization is effective in reducing athero-embolic brain injury and are associated with better prognosis.

Intimal aortic atherosclerosis in cardiac surgery: surgical strategies to prevent embolic stroke

 

OBJECTIVES

Although the incidence of perioperative stroke after cardiac surgery gradually decreased over the last decades, there is much variation between centres. This review aimed to create a concise overview of the evidence on possible surgical strategies to prevent embolic stroke in patients with intimal aortic atherosclerosis.

METHODS

The PubMed and EMBASE databases were searched for studies on surgical management of aortic atherosclerosis and the association with perioperative stroke in cardiac surgery, including specific searches on the most common types of surgery. Articles were screened with emphasis on studies comparing multiple strategies and studies reporting on the patients’ severity of aortic atherosclerosis. The main findings were summarized in a figure, with a grade of the corresponding level of evidence.

RESULTS

Regarding embolic stroke risk, aortic atherosclerosis of the tunica intima is most relevant. Although several strategies in general cardiac surgery seem to be beneficial in severe disease, none have conclusively been proven most effective. Off-pump surgery in coronary artery bypass grafting should be preferred with severe atherosclerosis, if the required expertise is present. Although transcatheter aortic valve replacement is used as an alternative to surgery in patients with a porcelain aorta, the risk profile concerning intimal atherosclerosis remains poorly defined.

CONCLUSIONS

A tailored approach that uses the discussed alternative strategies in carefully selected patients is best suited to reduce the risk of perioperative stroke without compromising other outcomes. More research is needed, especially on the perioperative stroke risk in patients with moderate aortic atherosclerosis.

Effectiveness and Safety of Transcatheter Aortic Valve Implantation for Aortic Stenosis in Patients With "Porcelain" Aorta

Surgical aortic valve replacement (SAVR) in patients with porcelain aorta is considered a high-risk procedure. Hence, transcatheter aortic valve implantation (TAVI) is emerging as the intervention of choice. However, there is a paucity of data directly comparing TAVI with SAVR in patients with porcelain aorta. We compared outcomes of TAVI versus SAVR in high-risk patients with porcelain between March 2012 and June 2015. The TAVI group included 54 patients, whereas 130 SAVR patients with porcelain aorta were identified (operated on between 2004 and 2015). Both groups were matched 1:1 based on the Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score with a 0.5% a priori caliper, resulting in 52 matched pairs. The mean STS-PROM was 7.3 ± 3.9 for both groups (p = 0.98), whereas mean age was 77.5 years for TAVI and 78.8 years for SAVR (p = 0.46). Compared with SAVR, TAVI patients had lower operative mortality (3.8% vs 17.3%; p = 0.052), significantly shorter median intensive care unit (40 vs 107 hours; p < 0.001) and hospital (5 vs. 7 days; p < 0.001) length of stay (LOS), but similar postoperative stroke rates (7.7% vs 11.5%; p = 0.74). One-year unadjusted survival was 81.7% (95% confidence interval [CI]: 69.8% to 93.5%) in the TAVI group versus 71.2% (95% CI: 61.0% to 85.1%) in the SAVR group, p = 0.093. Cox proportional hazard modeling identified preoperative chronic kidney disease (hazard ratio: 2.63 [95% CI: 1.03 to 6.70]; p = 0.043) and SAVR (hazard ratio: 2.641 [95% CI: 1.07 to 6.51]; p = 0.035) as significant predictors for decreased survival. Overall, TAVI was associated with reduced operative mortality, increased survival, and shorter intensive care unit and hospital length of stay compared with SAVR in patients with porcelain aorta. This study demonstrates that TAVI is a safe intervention in this high-risk population.

Risk factors of atheromatous aorta in cardiovascular surgery

Objective

To determine the prevalence and profile of ascending aorta or aortic arch atheromatous disease in cardiovascular surgery patients, its risk factors and its prognostic implication early after surgery.

Methods

Between January 2007 and June 2011, 2042 consecutive adult patients were analyzed, with no exclusion criteria. Atheromatous aorta diagnosis was determined intraoperatively by surgeon palpation of the aorta. Determinants of atheromatous aorta, as well as its prognostic implication were studied by multivariate logistic regression.

Results

Prevalence of atheromatous aorta was 3.3% (68 patients). Determinants were age > 61 years (OR= 2.79; CI95%= 2.43 - 3.15; P<0.0001), coronary artery disease (OR=3.1; CI95%=2.8 - 3.44; P=0.002), hypertension (OR=2.26; CI95%=1.82 - 2.7; P=0.03) and peripheral vascular disease (OR=3.15; CI95%= 2.83 - 3.46; P=0.04). Atheromatous aorta was an independent predictor of postoperative cerebrovascular accident (OR=3.46; CI95%=3.18 - 3.76; P=0.01).

Conclusion

Although infrequent, the presence of atheromatous aorta is associated with advanced age, hypertension, coronary artery disease and peripheral vascular disease. In those patients, a more detailed preoperative and intraoperative assessment of the aorta is justified, due to greater risk of postoperative cerebrovascular accident.

The calcified ascending aorta in aortic valve replacement: surgical strategies and results

PURPOSE

Calcification in the ascending aorta may constitute a major problem during aortic valve replacement (AVR). We examined the distributions of calcification and the associated operative strategies.

MATERIALS AND METHODS

Between 1999 and 2012, 207 consecutive, elderly patients underwent isolated AVR at our center. Computed tomographic scan data were available for all patients, and 105 were found to have at least one segment of calcification. Aortic calcifications were based on the section of the aorta that was calcified: distal, middle, and proximal of the ascending aorta.

RESULTS

Forty-six patients had calcification in the distal zone. In these patients, conventional cannulation was performed in 26 patients, with an associated in-hospital mortality of 7.7%. Arterial cannulation site was changed from the ascending aorta to somewhere in 20 patients (including other aortic sites in 9 patients, femoral artery in 7 patients, and both femoral and innominate arteries in 4 patients), without any patient deaths. Middle zone calcifications were observed in 70 patients: 63 underwent conventional cross-clamping with particular care (7.9% mortality), 5 underwent cross-clamping under direct vision during hypothermic circulatory arrest, and 2 underwent balloon occlusion. None of the patients undergoing substitute cross-clamping died. Proximal calcifications were observed in 66 patients; 47 patients underwent conventional transverse aortotomy, with an associated mortality of 8.5%.

CONCLUSION

Although the 8.3% mortality rate in patients undergoing conventional procedures was not negligible, it was lower than the expected 25.9% estimated by the patient EuroSCOREs. The conventional procedure results are reasonable, but may require a substitute procedure in some cases.

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.

Cardiac surgery in patients with a porcelain aorta in the era of transcatheter valve implantation

OBJECTIVES

New surgical and perfusion techniques allow the avoidance of deep hypothermia during open aortic arch surgery, which is generally necessary in patients with an unclampable porcelain aorta. The aim of the study was to evaluate operative and long-term results in patients with a porcelain aorta who underwent conventional cardiac surgery using current surgical and perfusion techniques.

METHODS

Between November 2003 and February 2012, 30 consecutive patients (mean age 68 ± 11 years, 10 patients had previous cardiac surgery with use of glue in 5 of them) with porcelain aorta diagnosed by computed tomography and defined as a severe circular calcification of the proximal thoracic aorta were referred for cardiac surgery. All patients underwent conventional surgery with arterial cannulation of the innominate (8) or a carotid artery (22) for arterial return. During mild hypothermic circulatory arrest, unilateral cerebral perfusion through the arterial line was performed for cerebral protection. The valve surgery consisted of aortic, mitral or double valve repair in 23, 3 and 4 cases, respectively. Aortic surgery (17 complete root replacements with valve composite grafts and 22 arch replacements) and coronary revascularization due to coronary heart disease (15) were the most frequent concomitant procedures.

RESULTS

Thirty-day mortality was 3.3% (1 patient died of bowel ischaemia caused by severe stenosis of the celiac and upper mesenteric arteries) and the rate of permanent neurological deficit was 3.3% as well. Two further patients died during the follow-up at age 91 and 82 years, respectively; however, no death was cardiac or valve related. The actuarial survival at 5 years was 87.3 ± 7.2%. There were no cardiac reoperations, new interventions or aortic- or valve-related events noted during the median follow-up of 45 months (range 0.1-106.0).

CONCLUSIONS

Conventional cardiac and aortic surgery offers definitive repair and can be performed safely using current perfusion and operative techniques. Although more invasive, this surgical technique provides mortality and morbidity rates that do not exceed those reported for transcatheter valve implantation. The curative replacement of the pathological proximal aorta, which is one of the most main sources of cerebral embolism, leads to excellent neurological outcome during mid- to long-term follow-up.