Coronary artery bypass grafting and perioperative stroke: imaging of atherosclerotic plaques in the ascending aorta with ungated high-pitch CT-angiography

Safety and Efficacy of Inner Branched Stent-Graft in the Treatment of Aortic Arch Disease: A Systematic Review

OBJECTIVE

To provide a descriptive overview on the contemporary outcomes of thoracic endovascular arch repair with inner branched endoprosthesis (bTEVAR) for the treatment of aortic arch pathologies.

METHODS

A comprehensive literature search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Pre-defined search terms were used to interrogate PubMed and OVID Medline databases from January 1999 to July 2022. Patient characteristics, indication for treatment, procedural data, mortality rates, postoperative complications, and reintervention rate during follow-up were evaluated.

RESULTS

Nineteen articles were included, encompassing a total of 618 patients who received bTEVAR, most of which were double-branched (63.9%, n=395). The main indication for treatment was aneurysm secondary to chronic aortic dissection (38.8%, n=240/618) with a mean maximum diameter of 58.3±11.4 mm. Pooled mean technical success rate was 97.4±4.4% (95% confidence interval [CI]=95.1%-99.5%); 2 and 3 patients required conversion to chimney technique and open repair, respectively. Among the pooled rates of early complications, postoperative stroke was the highest (10.5%; 95% CI=6.8%-14.3%). Thirty-day and in-hospital mortality rate was 5.5% (95% CI=2.6%-9.7%). Forty patients (6.5%; 95% CI=2.5%-9.5%) required early reintervention. During a mean follow-up of 20.7±13.5 months, the mortality rate was 18.2% (n=108/593; 95% CI=8.6%-20.6%) where 12 (11.1%) were aortic-related. Pooled late reintervention rate was 9.6% (95% CI=4.8%-14.3%). Comparison of demographics and outcomes found no significant difference between single and double bTEVAR.

CONCLUSION

Branched thoracic endovascular aortic repair is a promising approach for aortic arch pathologies with a high technical success rate despite a steep learning curve. However, contemporary outcomes reflect that postoperative stroke remains the predominant concern. Further experience and long-term follow-up are required to sufficiently elucidate the safety and durability of bTEVAR in the management of aortic pathologies for high-risk patients.

CLINICAL IMPACT

This systematic review summarized the contemporary outcomes of thoracic endovascular aortic repair with different inner branched stent-grafts for the management of aortic arch pathologies. Pooled results from nineteen studies with 618 patients demonstrated a high technical success rate and an acceptable mortality rate. However, postoperative stroke remains the major concern. Long-term follow-up is needed to evaluate its durability.

Iatrogenic Strokes and Covert Brain Infarcts After Percutaneous Cardiac Procedures: An Update

Millions of cardiac procedures are performed worldwide each year, making the potential complication of periprocedural iatrogenic stroke an important concern. These strokes can occur intraoperatively or within 30 days of a procedure and can be categorised as either overt or covert, occurring without obvious acute neurologic symptoms. Understanding the prevalence, risk factors, and strategies for preventing overt and covert strokes associated with cardiac procedures is imperative for reducing periprocedural morbidity and mortality. In this narrative review, we focus on the impacts of perioperative ischemic strokes for several of the most common interventional cardiac procedures, their relevance from a neurologic standpoint, and future directions for the care and research on perioperative strokes. Depending on the percutaneous procedure, the rates of periprocedural overt strokes can range from as little as 0.01% to as high as 2.9%. Meanwhile, covert brain infarctions (CBIs) occur much more frequently, with rates for different procedures ranging from 10%-84%. Risk factors include previous stroke, atherosclerotic disease, carotid stenosis, female sex, and African race, as well as other patient- and procedure-level factors. While the impact of covert brain infarctions is still a developing field, overt strokes for cardiac procedures lead to longer stays in hospital and increased costs. Potential preventative measures include screening and vascular risk factor control, premedicating, and procedural considerations such as the use of cerebral embolic protection devices. In addition, emerging treatments from the neurologic field, including neuroprotective drugs and remote ischemic conditioning, present promising avenues for preventing these strokes and merit investigation in cardiac procedures.

CALA: Cumulative Volume of Calcified Lesions of the Aorta in Cardiac Surgery

One of the major key questions raised in this retrospective study was to identify any correlation of atherosclerotic plaque volume of the ascending aorta and aortic arch with adverse events such as postoperative stroke, critical illness polyneuropathy and myopathy, as well as delirium and all-cause in-hospital mortality. In a second phase of this study, we investigated the relationship between atherosclerotic plaque volume and adverse events regarding the construction of proximal anastomosis on coronary artery bypass grafting procedures using different clamping techniques such as construction of anastomosis on cross-clamping or cross-clamping plus consecutive partial clamping of the aorta. The key findings of our research were that the size of calcium lesions of the ascending aorta and aortic arch correlates with early mortality, critical illness polyneuropathy/myopathy, and delirium but not with stroke. On the other hand, there were no significant differences between isolated cross-clamping versus cross-clamping plus consecutive partial clamping of the aorta regarding the primary adverse events by means of mean plaque volume.

Mortality Reduction After a Preincision Safety Check Before Cardiac Surgery: Is It the Aorta?

OBJECTIVES

The introduction and use of a preincision safety check were associated with lower mortality after mixed adult cardiac surgery; however, an explanatory mechanism is lacking. Stroke, one of the most severe complications after cardiac surgery, with high mortality, may be reduced by adapting the surgical handling of the ascending aorta. This study assessed the prevalence and predictors of this adaptation after a preincision safety check and the subsequent effect on outcome.

DESIGN

A prospective, single-center, observational study comparing adaptation with no-adaptation. The primary outcome measure was 30-day mortality. Multivariate analyses were performed to determine independent predictors of adaptation. To study the effect of adaptation on outcome, a propensity score-matched cohort was constructed in a 1:3 intervention:control ratio.

SETTING

At Isala Zwolle (NL), a large, nonacademic teaching hospital.

PARTICIPANTS

All consecutive cardiac surgery procedures from 2012 until 2015, including 4,752 surgeries.

INTERVENTIONS

The adaptation of surgical handling of the ascending aorta.

MEASUREMENTS AND MAIN RESULTS

In 283 cardiac surgeries (5.9%), adaptation was indicated. The most important independent predictors for adaptation were extracardiac atherosclerosis, current smoking, and increasing age. In the propensity score-matched cohort consisting of 1,069 procedures, there were no significant differences in outcome. After correction for propensity score, the hazard ratio of adaptation for 30-day mortality was 1.8 (0.85-3.79).

CONCLUSIONS

The adaptation of aortic surgical handling after a preincision safety check was necessary for 5.9% of cardiac surgeries, with extracardiac atherosclerosis as the strongest predictor. Outcome was not significantly different between patients with and without adaptation. Although promising, it remains unclear whether adaptation may fully explain mortality reduction after the use of a preincision safety check.

Potential nanotherapeutic strategies for perioperative stroke

AIMS

Based on the complex pathological environment of perioperative stroke, the development of targeted therapeutic strategies is important to control the development of perioperative stroke.

DISCUSSIONS

Recently, great progress has been made in nanotechnology, and nanodrug delivery systems have been developed for the treatment of ischemic stroke.

CONCLUSION

In this review, the pathological processes and mechanisms of ischemic stroke during perioperative stroke onset were systematically sorted. As a potential treatment strategy for perioperative stroke, the review also summarizes the multifunctional nanodelivery systems based on ischemic stroke, thus providing insight into the nanotherapeutic strategies for perioperative stroke.

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.

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.