Avoiding stroke during cardiac surgery

The Rationalisation of Intra-Operative Imaging During Cardiac Surgery: A Systematic Review

INTRODUCTION

One critical complication of cardiac surgery is cerebrovascular accidents (CVAs). Ascending aorta atherosclerosis poses a significant risk of embolisation to distal vessels and to cerebral arteries. Epi-aortic ultrasonography (EUS) is thought to offer a safe, high-quality accurate visualisation of the diseased aorta to guide the surgeon on the best surgical approach to the planned procedure and potentially improve neurological outcomes post-cardiac surgery.

METHOD

The authors conducted a comprehensive search of PubMed, Scopus and Embase. Studies that reported on epi-aortic ultrasound use in cardiac surgery were included. Major exclusion criteria were: (1) abstracts, conference presentations, editorials, literature reviews; (2) case series with <5 participants; (3) epi-aortic ultrasound in trauma or other surgeries.

RESULTS

A total of 59 studies and 48,255 patients were included in this review. Out of the studies that reported patient co-morbidities prior to cardiac surgery, 31.6% had diabetes, 59.5% had hyperlipidaemia and 66.1% had a diagnosis of hypertension. Of those that reported significant ascending aorta atherosclerosis found on EUS, this ranged from 8.3% of patients to 95.2% with a mean percentage of 37.8%. Hospital mortality ranged from 7% to 13%; four studies reported zero deaths. Long-term mortality and stroke rate varied significantly with hospital duration.

CONCLUSION

Current data have shown EUS to have superiority over manual palpation and transoesophageal echocardiography in the prevention of CVAs following cardiac surgery. Yet, EUS has not been implemented as a routine standard of care. Extensive adoption of EUS in clinical practice is warranted to aid large, randomised trials before making prospective conclusions on the efficacy of this screening method.

Novel use of the Sentinel cerebral protection device during thrombosed septal occluder explant and Atriclip appendage closure

BACKGROUND

Our case demonstrates a novel use of the Sentinel™ cerebral protection device (SCPD) for prevention of stroke during removal of a thrombus-adherent atrial septal occluder.

CASE PRESENTATION

A 45-year-old male with multiple strokes and ostium secundum atrial septal defect closed ten years prior using an Amplatzer Septal Occluder presented with recurrent neurologic symptoms. Over the ensuing year, serial transesophageal echocardiography revealed persistent and worsening device-adherent thrombus despite trial of different anticoagulants. The device appeared to be mal-deployed, prompting the decision for surgical explant. Given concern for embolization during explant, an SCPD was placed. Excision, pericardial patch repair, and Atriclip appendage closure (AAC) were performed. The device demonstrated incomplete endothelialization and microthrombi. SCPD filtration revealed embolic debris.

CONCLUSIONS

We demonstrate the first successful use of an SCPD during surgical excision of a mal-deployed occluder. With its ease of use and safety, SCPD may have utility in surgeries with high cardio-embolic risk.

[Differential diagnosis of neurological conditions in cardiac patients on the first day after cardiac, ascending aortic and aortic arch surgery and repair of internal carotid arteries]

The review is devoted to analysis of current trends in interdisciplinary approach to the differential diagnosis of patients' conditions on the first day after cardiac, ascending aortic and aortic arch surgery and repair of internal carotid arteries (neurological disorders, delirium, cognitive dysfunction, psycho-emotional disorders, postoperative sedation). This approach is valuable to determine the prognosis and timely treatment. The basic concepts reflecting the discussion between neurologists, cardiovascular surgeons, anesthetists, radiation diagnostics specialists and rehabilitators are summarized. The authors concluded that timely and correct differential diagnosis of the states on the first postoperative day using current tests and interdisciplinary approach to the treatment of patients with postoperative impaired consciousness or neurological/psycho-emotional dysfunction can improve their quality of life and efficiency of medical care.

A Systemic Review of Functional Near-Infrared Spectroscopy for Stroke: Current Application and Future Directions

Background: Survivors of stroke often experience significant disability and impaired quality of life. The recovery of motor or cognitive function requires long periods. Neuroimaging could measure changes in the brain and monitor recovery process in order to offer timely treatment and assess the effects of therapy. A non-invasive neuroimaging technique near-infrared spectroscopy (NIRS) with its ambulatory, portable, low-cost nature without fixation of subjects has attracted extensive attention. Methods: We conducted a comprehensive literature review in order to review the use of NIRS in stroke or post-stroke patients in July 2018. NCBI Pubmed database, EMBASE database, Cochrane Library and ScienceDirect database were searched. Results: Overall, we reviewed 66 papers. NIRS has a wide range of application, including in monitoring upper limb, lower limb recovery, motor learning, cortical function recovery, cerebral hemodynamic changes, cerebral oxygenation, as well as in therapeutic method, clinical researches, and evaluation of the risk for stroke. Conclusions: This study provides a preliminary evidence of the application of NIRS in stroke patients as a monitoring, therapeutic, and research tool. Further studies could give more emphasize on the combination of NIRS with other techniques and its utility in the prevention of stroke.

Cerebral perfusion monitoring in adult patients following cardiac surgery: an observational study

BACKGROUND

Following adult cardiac surgery, often difficult to detect fluctuations in regional cerebral perfusion can contribute to strokes. Optimal cerebral perfusion remains elusive and traditional monitoring strategies do not consistently identify acute changes. Non-invasive cerebral oximetry may detect perfusion variations.

OBJECTIVE

To assess the feasibility of postoperative non-invasive cerebral oximetry monitoring.

METHODS

Non-invasive cerebral oximetry was performed on adult aortic valve surgery patients in a cardiac surgical intensive care unit. Monitoring feasibility was assessed using an investigator-developed, data extraction tool.

RESULTS

Non-invasive cerebral oximetry was completed in 94% of patients. Sixty percent had values that fell below pre-set ischemic threshold. Nurses reported monitoring was feasible, and they perceived identifying deleterious cerebral perfusion trends may improve patient care.

CONCLUSIONS

Prevalence of low cerebral oximetry values underscores the importance of increasing sensitivity of monitoring tools. Further evaluation is required to assess this modality and the role of nurses in optimizing neurocognitive outcomes. Impact statement: Cerebral oximetry monitoring may help identify adult patients at risk of neurological complications after cardiac surgery, and as a consequence initiate definitive therapeutic strategies.

Incidence, characteristics and functional implications of cerebral embolic lesions after the MitraClip procedure

AIMS

This study aimed to assess the incidence and impact of cerebral embolic events after the MitraClip procedure.

METHODS AND RESULTS

Twenty-seven high-risk patients (logistic EuroSCORE I 25±15%) underwent the MitraClip procedure and cerebral diffusion-weighted magnetic resonance imaging (MRI) in median two days before and three days after the procedure. On the same day, neurocognitive function was assessed using the Montreal Cognitive Assessment (MoCA) questionnaire and thorough clinical examination. Comparison of pre- and post-interventional MRI showed that 23 of 27 patients (85.7%) had newly acquired microembolic lesions with in median three (interquartile range 1-9) new lesions per patient. Of these, three patients (11.1%) had lesions with diameter >5 mm. Patients with >3 new cerebral embolic lesions (n=13, 48%) had a lower post-interventional MoCA score in comparison to patients with ≤3 embolic lesions (23.6±3.6 vs. 20.3±4.5; p=0.046) in univariate analysis. Multivariate stepwise regression analysis identified device time as an independent predictor of the number of post-procedural new lesions (p=0.003) and, for reduced post-interventional MoCA score, a low MoCA score at baseline (p<0.001).

CONCLUSIONS

The MitraClip procedure results in new ischaemic cerebral lesions in the vast majority of patients. Preliminary data suggest that these lesions are clinically without significant impact on global cognitive function. ClinicalTrials.gov: NCT01288976.

Addressing the Global Burden of Trauma in Major Surgery

Despite a technically perfect procedure, surgical stress can determine the success or failure of an operation. Surgical trauma is often referred to as the "neglected step-child" of global health in terms of patient numbers, mortality, morbidity, and costs. A staggering 234 million major surgeries are performed every year, and depending upon country and institution, up to 4% of patients will die before leaving hospital, up to 15% will have serious post-operative morbidity, and 5-15% will be readmitted within 30 days. These percentages equate to around 1000 deaths and 4000 major complications every hour, and it has been estimated that 50% may be preventable. New frontline drugs are urgently required to make major surgery safer for the patient and more predictable for the surgeon. We review the basic physiology of the stress response from neuroendocrine to genomic systems, and discuss the paucity of clinical data supporting the use of statins, beta-adrenergic blockers and calcium-channel blockers. Since cardiac-related complications are the most common, particularly in the elderly, a key strategy would be to improve ventricular-arterial coupling to safeguard the endothelium and maintain tissue oxygenation. Reduced O2 supply is associated with glycocalyx shedding, decreased endothelial barrier function, fluid leakage, inflammation, and coagulopathy. A healthy endothelium may prevent these "secondary hit" complications, including possibly immunosuppression. Thus, the four pillars of whole body resynchronization during surgical trauma, and targets for new therapies, are: (1) the CNS, (2) the heart, (3) arterial supply and venous return functions, and (4) the endothelium. This is termed the Central-Cardio-Vascular-Endothelium (CCVE) coupling hypothesis. Since similar sterile injury cascades exist in critical illness, accidental trauma, hemorrhage, cardiac arrest, infection and burns, new drugs that improve CCVE coupling may find wide utility in civilian and military medicine.

The effectiveness of the correction of cognitive impairment using computer-based stimulation programs for patients with coronary heart disease after coronary bypass surgery

We evaluated effectiveness of using copyrighted computer-based stimulation programs in the correction of cognitive function in patients with coronary heart disease after coronary bypass surgery.A total of 74 patients were examined, all the patients underwent a course of drug therapy, 37 patients underwent a course of rehabilitation in addition to medical therapy using computer-based stimulation programs (1 time per day for 20 min within 10 days). A course of rehabilitation using computer-based stimulation programs in patients with coronary heart disease after coronary bypass surgery was proved to be an effective way of correcting cognitive function.

Short-term preoperative dietary restriction is neuroprotective in a rat focal stroke model

Stroke is a major complication of cardiovascular surgery, resulting in over 100,000 deaths and over a million postoperative encephalopathies annually in the US and Europe. While mitigating damage from stroke after it occurs has proven elusive, opportunities to reduce the incidence and/or severity of stroke prior to surgery in at-risk individuals remain largely unexplored. We tested the potential of short-term preoperative dietary restriction to provide neuroprotection in rat models of focal stroke. Rats were preconditioned with either three days of water-only fasting or six days of a protein free diet prior to induction of transient middle cerebral artery occlusion using two different methods, resulting in either a severe focal stroke to forebrain and midbrain, or a mild focal stroke localized to cortex only. Infarct volume, functional recovery and molecular markers of damage and protection were assessed up to two weeks after reperfusion. Preoperative fasting for 3 days reduced infarct volume after severe focal stroke. Neuroprotection was associated with modulation of innate immunity, including elevation of circulating neutrophil chemoattractant C-X-C motif ligand 1 prior to ischemia and suppression of striatal pro-inflammatory markers including tumor necrosis factor α, its receptor and downstream effector intercellular adhesion molecule-1 after reperfusion. Similarly, preoperative dietary protein restriction for 6 days reduced ischemic injury and improved functional recovery in a milder cortical infarction model. Our results suggest that short-term dietary restriction regimens may provide simple and translatable approaches to reduce perioperative stroke severity in high-risk elective vascular surgery.

Risk factors for early postoperative cognitive dysfunction after non-coronary bypass surgery in Chinese population

Background

The present study was performed to investigate the incidence of early postoperative cognitive dysfunction (POCD) after non-coronary bypass surgery and the potential risk factors in Chinese population.

Methods

We performed a prospective study in a teaching tertiary hospital from May 2012 to August 2012. One hundred and seventy-six adult patients undergoing non-coronary bypass surgery were recruited. Mini-Mental State Examination (MMSE) score was evaluated before and 3 to 5 days after surgery. Patients with a MMSE score reduction of 2 was diagnosed with POCD.

Results

The general incidence of POCD was 33.0%, with no significant difference between the types of surgeries. In the univariate analysis, POCD associated factors included age, duration of surgery, anesthesia, cardiopulmonary bypass (CPB), cross-clamp and rewarming, and sevoflurane concentration. However, only age, cross-clamp duration and sevoflurane concentration were demonstrated to be independent risk factors for POCD.

Conclusion

Incidence of early POCD after non-coronary bypass surgery was relatively high in Chinese population. Advanced age, longer aortic cross-clamp duration and lower sevoflurane concentration was associated with a higher incidence of POCD.

Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era?

Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.

The Perceval S aortic valve has the potential of shortening surgical time: does it also result in improved outcome?

BACKGROUND

Sutureless aortic valve prostheses have the potential of shortening surgical time. However, whether shorter operative times may also result in improved patient outcomes remains to be established.

METHODS

One hundred patients underwent minimally invasive isolated aortic valve replacement. Of these, 50 patients received a Perceval (Sorin Group, Saluggia, Italy) bioprosthesis (group P) and 50 patients received a non-Perceval valve (group NP).

RESULTS

The group P patients were older (77.5 ± 5.3 versus 71.7 ± 10 years, p = 0.001) and at higher risk (logistic European System for Cardiac Operative Risk Evaluation [EuroSCORE] 9.9 ± 6.5 versus 4.3 ± 1, p = 0.001) than group NP patients. One implant failure occurred in group P (p = 0.5), and conversion to full sternotomy was necessary in 1 patient from each group. Aortic cross-clamp and cardiopulmonary bypass times were 39.4% and 34% shorter in group P (both p < 0.001). Within 30 days, a total of 5 patients died (2 in group P and 3 in group NP, p = 0.5). No significant differences were observed between groups in postoperative arrhythmias and need for pacemaker implantation (p = 0.3 and p = 0.5, respectively). Despite the higher surgical risk, group P patients less frequently required blood transfusion (1.1 ± 1.1 units versus 2.3 ± 2.8 units, p = 0.007), and had a shorter intensive care unit stay (1.9 ± 0.7 versus 2.8 ± 1.9 days, p = 0.002) and a shorter intubation time (9.2 ± 3.6 hours versus 15 ± 13.8 hours, p = 0.01). Group NP patients had a mean prosthesis size significantly smaller than for group P (23 ± 2 mm versus 23.9 ± 1.1 mm, p = 0.01). The Perceval valve provided comparable hemodynamic performance to that of non-Perceval valves (mean gradient 8.4 ± 6 mm Hg versus 10 ± 4.9 mm Hg, p = 0.24).

CONCLUSIONS

Sutureless implantation of the Perceval valve is associated with shorter cross-clamp and cardiopulmonary bypass times, resulting in improved clinical outcome. In addition, it compares favorably with conventional valves in terms of mortality and outcome variables.

Low-dose GYKI-52466: prophylactic preconditioning confers long-term neuroprotection and functional recovery following hypoxic-ischaemic brain injury

Experimental preconditioning provides beneficial outcomes in conditions such as cardiac surgery, brain surgery and stroke. Here we evaluated the protective effects of low-dose subcutaneous GYKI-52466 preconditioning in a rat model of hypoxic-ischaemic (HI) brain injury. Male Sprague-Dawley rats (postnatal day 26) were administered saline or GYKI-52466 (GYKI; 3-mg/kg, 90 min; 1-mg/kg, twice in 120 min; or 0.5-mg/kg, thrice in 180 min) prior to left common carotid artery occlusion. Animals were allowed to recover for 2h, and then placed in a hypoxia chamber (8% O₂/92% N₂; 33 ± 1°C) for 1h. A sham surgery group received saline without HI. Seizure activity was scored during hypoxia and sensorimotor tests performed before surgery and at 1, 7, 14 and 90 days post-HI. On days 14 and 90 brains were fixed and sectioned for the assessment of infarct size and ventricular enlargement. Low-dose GYKI-52466 preconditioning significantly reduced infarct volume and ventricular enlargement relative to saline-treated controls at day 14 after HI. On day 90, tissue loss was significantly reduced by GYKI 3-mg/kg compared to saline. Foot-faults, paw use asymmetry, and postural reflex scores were significantly improved in all GYKI treatment groups. Our results show that GYKI-52466 is effective at doses well-below, and at pre-administration intervals well-beyond previous studies, and suggest that a classical blockade of ionotropic AMPA receptors does not underlie its neuroprotective effects. Low-dose GYKI-52466 preconditioning represents a novel, prophylactic strategy for neuroprotection in a field almost devoid of effective pharmaceuticals.

Acute aortic dissection type A

Background

Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.

Methods

Based on a MEDLINE search the latest literature on this topic was reviewed. Results from the German Registry for Acute Aortic Dissection Type A (GERAADA) are also described.

Results

Currently, the perioperative mortality rate of AADA is below 20 per cent, the rate of definitive postoperative neurological impairment approaches 12 per cent and the long-term prognosis after surviving the acute phase of the disease is good. Many pathology- and therapy-associated factors influence the outcome of AADA, including prompt diagnosis with computed tomography and better cerebral protection strategies during aortic arch reconstruction. Endovascular technologies are emerging that may lead to less invasive treatment options.

Conclusion

AADA is an emergency that can present with a wide variety of clinical scenarios. Advances in the surgical management of this complex disease are improving outcomes.