Guidelines for the Performance of a Comprehensive Intraoperative Epiaortic Ultrasonographic Examination: Recommendations of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists; Endorsed by the Society of Thoracic Surgeons

Clinical relevance of transcranial Doppler in a cardiac surgery setting: embolic load predicts difficult separation from cardiopulmonary bypass

BACKGROUND

During cardiac surgery, transcranial Doppler (TCD) represents a non-invasive modality that allows measurement of red blood cell flow velocities in the cerebral arteries. TCD can also be used to detect and monitor embolic material in the cerebral circulation. Detection of microemboli is reported as a high intensity transient signal (HITS). The importance of cerebral microemboli during cardiac surgery has been linked to the increased incidence of postoperative renal failure, right ventricular dysfunction, and hemodynamic instability. The objective of this study is to determine whether the embolic load is associated with hemodynamic instability during cardiopulmonary bypass (CPB) separation and postoperative complications.

METHODS

A retrospective single-centre cohort study of 354 patients undergoing cardiac surgery between December 2015 and March 2020 was conducted. Patients were divided in tertiles, where 117 patients had a low quantity of embolic material (LEM), 119 patients have a medium quantity of microemboli (MEM) and 118 patients who have a high quantity of embolic material (HEM). The primary endpoint was a difficult CPB separation. Multivariate logistic regression was used to determine the potential association between a difficult CPB separation and the number of embolic materials.

RESULTS

Patients who had a difficult CPB separation had more HITS compared to patients who had a successful CPB separation (p < 0.001). In the multivariate analysis, patients with MEM decreased their odds of having a difficult CPB weaning compared to patients in the HEM group (OR = 0.253, CI 0.111-0.593; p = 0.001). In the postoperative period patients in the HEM group have a higher Time of Persistent Organ Dysfunction (TPOD), a longer stay in the ICU, a longer duration under vasopressor drugs and a higher mortality rate compared to those in the MEM and LEM groups.

CONCLUSION

The result of this study suggests that a high quantity of cerebral embolic material increases the odds of having a difficult CPB separation. Also, it seems to be associated to more complex surgery, a longer CPB time, a higher TPOD and a longer stay in the ICU. Six out of eight patients who died in this cohort were in the HEM group.

Perioperative Care of the Patient with Eye Pathologies Undergoing Nonocular Surgery

The authors reviewed perioperative ocular complications and implications of ocular diseases during nonocular surgeries. Exposure keratopathy, the most common perioperative eye injury, is preventable. Ischemic optic neuropathy, the leading cause of perioperative blindness, has well-defined risk factors. The incidence of ischemic optic neuropathy after spine fusion, but not cardiac surgery, has been decreasing. Central retinal artery occlusion during spine fusion surgery can be prevented by protecting eyes from compression. Perioperative acute angle closure glaucoma is a vision-threatening emergency that can be successfully treated by rapid reduction of elevated intraocular pressure. Differential diagnoses of visual dysfunction in the perioperative period and treatments are detailed. Although glaucoma is increasingly prevalent and often questions arise concerning perioperative anesthetic management, evidence-based recommendations to guide safe anesthesia care in patients with glaucoma are currently lacking. Patients with low vision present challenges to the anesthesia provider that are becoming more common as the population ages.

The Epiaortic Ultrasound Diagnosis of Iatrogenic Subadventitial Hematoma

Iatrogenic aortic injury is a rare but potentially lethal complication of cardiac surgery. While sometimes resulting in aortic dissection or intramural hematoma, injury more frequently results in subadventitial hematoma, a more benign pathology. Here, we describe a case where intraoperative transesophageal echocardiography (TEE) identified such a hematoma but was unable to rule out dissection. Epiaortic ultrasound was subsequently performed, which definitively demonstrated the absence of a dissection flap or extraluminal flow. Per our review, this is the first report documenting the successful use of epiaortic imaging to identify subadventitial hematoma in the setting of inconclusive TEE findings.

Diagnostic challenges with transesophageal echocardiography for intraoperative iatrogenic aortic dissection: Role of epiaortic ultrasound

Iatrogenic aortic dissection is a rare and serious complication of cardiac surgery with an incidence between 0.12% and 0.16%. Dissections involving an intimal flap can be detected using trans-esophageal echocardiography (TEE) with a sensitivity of 94%–100% and specificity of 77%–100%. Rarely, dissections can occur that are not detectable by TEE. There have been reports of iatrogenic dissection in the ascending aortic cannulation site; however, a dissection at the antegrade cardioplegia cannulation site is very rare. It also presents challenges associated with early diagnosis and appropriate intervention. We are describing a rare case of aortic dissection at the antegrade cardioplegia cannulation site in the proximal ascending aorta. The dissection was unable to be visualized with TEE initially, and required epi-aortic ultrasound to diagnose dissection in timely manner.

The evolving role of the modern perfusionist: insights from transesophageal echocardiography

Transesophageal echocardiography is a relatively non-invasive, mobile, safe imaging technique that is ideal for providing real-time information on cardiac anatomy and function during heart surgery. The technology has evolved from two-dimensional to real-time three-dimensional imaging during cardiac procedures, which has significantly benefited preoperative planning, intraoperative guidance, evaluation, and postoperative follow-up. Transesophageal echocardiography may serve the clinical perfusionist by providing imaging guidance for identifying potential problems before cardiopulmonary bypass, guiding the proper placement of cannulas, monitoring cardiac performance on cardiopulmonary bypass, and providing useful feedback during weaning from cardiopulmonary bypass. Although the perfusionist should be able to understand all echocardiographic images and measurements in depth, perfusion-related echocardiographic information can or should be used to optimize the clinical practice of the modern perfusionist. Vice versa, whenever the perfusionist suspects a problem, the surgical team including the sonographer should verify this "clinical treat" by echocardiography whenever possible.

Neurological complications after cardiac surgery: anesthetic considerations based on outcome evidence

Neurological complications after cardiac surgery remain prevalent. This review aims to discuss the modifiable and outcome-relevant risk factors based on an up-to-date literature review, with a focus on interventions that may improve outcomes.

Difficult TEE Probe Placement: The Evidence, Troubleshooting Techniques, and a Guide to Alternative Monitoring Options for Intraoperative Physicians

Transesophageal echocardiography (TEE) imaging has become an essential component of many open and interventional cardiac procedures and has increasing use in monitoring for noncardiac procedures, partly because of an aging population. Whether expected or not, encountering difficulty when inserting the TEE probe presents the anesthesiologist with a conundrum. Repeated insertion attempts increase the risk of a serious complication; however, proceeding without TEE may be unacceptable to the proceduralist or surgeon. The aim of this review is to present the spectrum of complications possible with TEE, propose several evidence-based insertion tips, examine potential alternative cardiac imaging options, and finally, propose a roadmap for providers who encounter difficulty when placing a TEE probe.

Neurocognitive Function after Cardiac Surgery: From Phenotypes to Mechanisms

For half a century, it has been known that some patients experience neurocognitive dysfunction after cardiac surgery; however, defining its incidence, course, and causes remains challenging and controversial. Various terms have been used to describe neurocognitive dysfunction at different times after cardiac surgery, ranging from "postoperative delirium" to "postoperative cognitive dysfunction or decline." Delirium is a clinical diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Postoperative cognitive dysfunction is not included in the DSM-5 and has been heterogeneously defined, though a recent international nomenclature effort has proposed standardized definitions for it. Here, the authors discuss pathophysiologic mechanisms that may underlie these complications, review the literature on methods to prevent them, and discuss novel approaches to understand their etiology that may lead to novel treatment strategies. Future studies should measure both delirium and postoperative cognitive dysfunction to help clarify the relationship between these important postoperative complications.

Intraoperative aortic dissection

Intraoperative aortic dissection is a rare but fatal complication of open heart surgery. By recognizing the population at risk and by using a gentle operative technique in such patients, the surgeon can usually avoid iatrogenic injury to the aorta. Intraoperative transesophageal echocardiography and epiaortic scanning are invaluable for prompt diagnosis and determination of the extent of the injury. Prevention lies in the strict control of blood pressure during cannulation/decannulation, construction of proximal anastomosis, or in avoiding manipulation of the aorta in high-risk patients. Immediate repair using interposition graft or Dacron patch graft is warranted to reduce the high mortality associated with this complication.

Imaging Techniques for Diagnosis of Thoracic Aortic Atherosclerosis

The most severe complications after cardiac surgery are neurological complications including stroke which is often caused by emboli merging from atherosclerosis in the ascending aorta to the brain. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation. Several techniques are available to screen the ascending aorta, for example, transesophageal echocardiography (TEE), epiaortic ultrasound, TEE A-view method, manual palpation, computed tomography, and magnetic resonance imaging. This paper provides a description of the advantages and disadvantages of these imaging techniques.

Perioperative management of combined carotid and coronary artery bypass grafting procedures

The objective of this review is to provide a high level overview on current thinking for treatment of patients with combined carotid and coronary artery disease given that these patients are at higher risk of adverse cardiac events, stroke, and death. This review discusses (1) the current literature addressing perioperative stroke risk in the setting of coronary artery bypass graft, (2) the literature regarding different surgical approaches when both carotid and coronary revascularization are being considered, and (3) the data available to guide optimal management of this complex patient population to minimize complications regardless of the surgical approach taken.

Neurological complications of cardiac surgery

As increasing numbers of elderly people undergo cardiac surgery, neurologists are frequently called upon to assess patients with neurological complications from the procedure. Some complications mandate acute intervention, whereas others need longer term observation and management. A large amount of published literature exists about these complications and guidance on best practice is constantly changing. Similarly, despite technological advances in surgical intervention and modifications in surgical technique to make cardiac procedures safer, these advances often create new avenues for neurological injury. Accordingly, rapid and precise neurological assessment and therapeutic intervention rests on a solid understanding of the evidence base and procedural variables.

Anesthetic Management for Cardiopulmonary Bypass

Cardiopulmonary bypass has revolutionized the practice of cardiac surgery and allows safe conduct of increasingly complex cardiac surgery. A brief review of the bypass circuit is undertaken in this review. A more thorough review of the anesthetic management is accomplished including choice of anesthetic medications and their effects. The inflammatory response to cardiopulmonary bypass is reviewed along with interventions that may help ameliorate the inflammation.

Perioperative transesophageal echocardiography for aortic dissection

PURPOSE

Aortic dissection is an infrequent but serious condition that often requires immediate operative intervention. We explore recent developments in the classification of aortic dissection and perioperative transesophageal echocardiography that assist with quantifying the severity of disease and facilitate its management.

PRINCIPAL FINDINGS

We describe the pivotal role of echocardiography in relation to key surgical considerations such as cannulation, aortic root surgery, perfusion in the aortic arch vessels, stenting in hybrid arch repair, and timing of preventative surgery.

CONCLUSION

Developments in the classification of aortic dissection have improved our perspective and understanding of the key presenting features that affect mortality. Improvements in patient outcome may be achieved in part by appropriately timed echocardiography-guided surgery.

Outcome of elective total aortic arch replacement in patients with non-dialysis-dependent renal insufficiency stratified by estimated glomerular filtration rate

OBJECTIVE

Little is known about the impact of preoperative renal function stratified by estimated glomerular filtration rate (eGFR) on outcomes of total aortic arch replacement (TAR). The current study addressed this issue and identified a cutoff value of eGFR for the requirement of postoperative renal replacement therapy.

METHODS

From January 2000 to May 2011, 229 consecutive patients who did not require preoperative hemodialysis were retrospectively studied after elective TAR. Patients were grouped into the following categories: those with normal renal function (eGFR >90 mL/min/1.73 m(2); n = 11) and those with mild (eGFR, 60-90 mL/min/1.73 m(2); n = 86), moderate (eGFR, 30-59 mL/min/1.73 m(2); n = 111), or severe (eGFR <30 mL/min/1.73 m(2); n = 21) renal dysfunction. Linear trend tests demonstrated that the lower categories of eGFR were associated with a higher age, hypertension, coronary artery disease, peripheral arterial disease, and a higher EuroSCORE II.

RESULTS

The overall hospital mortality was 2.2%. A lower categories of eGFR were an independent risk factor for hospital mortality (odds ratio, 0.91; P = .002) and postoperative renal replacement therapy (odds ratio, 0.94; P < .002). A cutoff value for the requirement of postoperative renal replacement therapy was 26.0 mL/min/1.73 m(2). Patients in the lower categories of eGFR had significantly higher hospital mortality (P = .03) and more morbidities, such as renal replacement therapy (P < .01), postoperative permanent neurologic deficits (P = .013), and prolonged mechanical ventilatory support (P < .01). Midterm survival and freedom from major adverse cerebrocardiovascular events were worse across the levels of the lower categories of eGFR.

CONCLUSIONS

Preoperative eGFR is a strong predictor of short- and midterm outcomes in contemporary TAR.

Stroke prevention in cardiac surgery

This article addresses the main risk factors for stroke in cardiac surgery and discusses the role of carotid artery intervention and peri-operative epi-aortic scanning in the prevention of stroke. In great Britain and Northern Ireland, there were ∼2789 new strokes following the 105,558 cases of cardiac surgery from 2004 to 2008 (an annual stroke rate of 2.6% complicating heart surgery in the UK). We argue that The National Health Service in the UK is set to spend £187,682 preventing each stroke in some 30 cardiac surgical patients while ignoring the remaining 528 strokes that complicate cardiac surgery in the UK each year. Caution must be taken in pricing the prevention of perioperative stroke as we must question our use of finite resources. Aortic atheroma has been demonstrated as the foremost cause of post-coronary artery bypass graft strokes. Epi-aortic scanning is effective in identifying aortic atheroma encouraging measures to reduce perioperative stroke with heart surgery, and it is cheap. Several studies have confirmed epi-aortic scanning at the time of heart surgery to be effective in reducing the incidence of perioperative brain damage. We suggest that it is time to adopt epi-aortic scanning in our routine cardiac surgical practice if only to confirm or refute its cost-effectiveness in brain protection during this surgery.