Perioperative stroke: time to redefine the impact of age?

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.

A Single Center Study on the Risks of Peri-Intervention Stroke in Thoracic Endovascular Aortic Repair (TEVAR) and Endovascular Abdominal Aortic Repair (EVAR)

(1) Background: The risk factors of peri-intervention stroke (PIS) in thoracic endovascular aortic repair (TEVAR) and endovascular abdominal aortic repair (EVAR) are different. This study aimed to compare the risks of PIS in both interventions. (2) Methods: Patients who had suffered a PIS related to TEVAR or EVAR from January 2008 to June 2015 in Songklanagarind Hospital were selected as the cases, while patients who had not suffered PIS were randomly selected to create a 1:4 case: control ratio for analysis. The associations between the factors from pre- to post-intervention and PISs in TEVAR or EVAR cases were analyzed by univariable analysis (p < 0.1). The independent risks of PIS were identified by multivariable analysis and presented in odds ratios (p < 0.05). (3) Results: A total of 17 (2.2%) out of 777 patients who had undergone TEVAR or EVAR experienced PIS, of which 9/518 (1.7%) and 8/259 (3.1%) cases were in TEVAR and EVAR groups, respectively. PIS developed within the first 24 h in nine (52.9%) cases. Large vessel ischemic stroke or watershed infarctions were the most common etiologies of PIS. The independent risks of PIS were the volume of intra-intervention blood loss (1.99 (1.88–21.12), p < 0.001) in the TEVAR-related PIS, and intervention time (2.16 (1.95–2.37), p = 0.010) and post-intervention hyperglycemia (18.60 (1.60–216.06), p = 0.001) in the EVAR-related PIS. There were no differences in the rate of PIS among the operators, intervention techniques, and status of the interventions performed. (4) Conclusion: The risks of PIS in TEVAR or EVAR in our center were different and possibly independent of the operator expertise and intervention techniques.

Timing of Recognition for Perioperative Strokes Following Cardiac Surgery

INTRODUCTION

More than half of reported perioperative strokes following cardiac surgery are identified beyond postoperative day one. The objective of our study was to determine preoperative and intraoperative factors that are associated with stroke following cardiac surgery and to identify factors that may contribute delayed recognition of perioperative stroke.

METHODS

Patients undergoing coronary artery bypass surgery or isolated valve surgery from January 2, 2015 to April 28, 2017 at an academic health system were identified from the Society of Thoracic Surgeons Registry. We determined preoperative and intraoperative factors associated with perioperative stroke. Two neurologists performed retrospective chart reviews on perioperative stroke patients to determine the last seen well time and the stroke cause.

RESULTS

During the study period, 2795 patients underwent coronary artery bypass surgery or isolated valve surgery (mean age 64 ± 11 years, 71% male, 72% Caucasian, 9% history of stroke), of which 43 (1.5%) had a perioperative stroke; 31 (72%) patients had an embolic mechanism of stroke based on neuroimaging. In multivariable analysis, perioperative strokes were independently associated with increasing age (OR 1.04, 95% 1.01-1.07), history of stroke (OR 2.73, 95% CI 1.47-5.06), and history of thoracic aorta disease (OR 3.36, 95% CI 1.16-9.71). Strokes were identified after postoperative day one in 32 (74%) patients of which 26 (81%) had a preoperative last seen well time.

CONCLUSION

Given the high frequency of preoperative last seen well time in perioperative stroke patients who are identified after postoperative day one, delayed stroke recognition may contribute to the bimodal distribution in timing of perioperative stroke. Frequent neurological monitoring within 24 hours after CABG or isolated valve surgery should be considered for all patients undergoing cardiac surgery, particularly elderly patients and those with a history of stroke or thoracic aorta disease, to improve early stroke recognition.

The Incidence of Perioperative Stroke: Estimate Using State and National Databases and Systematic Review

Background and Purpose

Perioperative stroke remains a devastating complication after surgical procedures, due to hemodynamic and inflammatory changes that increase the risk of strokes within 30 days following surgery. We aimed to assess the incidence of perioperative strokes in patients undergoing various surgical procedures and reach a national estimate.

Methods

A retrospective cohort study was conducted using California State Inpatient Databases, State Emergency Department Databases, State Ambulatory Surgery and Services Databases, and the National Inpatient Sample (NIS) during the period 2008 to 2011 from the Healthcare Cost and Utilization Project. A systematic review was conducted using PubMed, Embase, and Web of Science databases to obtain published articles that reported the incidence of perioperative stroke in various surgical procedures.

Results

Analysis of 3,694,410 surgical encounters from the state of California (mean±standard deviation age: 52.4±21.1 years) yielded an overall rate of perioperative stroke of 0.32% (n=11,759). The incidence of perioperative strokes was highest following neurological (1.25%), vascular (1.07%), and cardiac (0.98%) surgeries. The NIS database contained a total of 48,672,974 weighted hospitalizations and yielded a rate of perioperative stroke of 0.42% (n=204,549). The systematic review completed yielded 187 articles, which had an overall sample size of 184,922 and an incidence of perioperative stroke ranging from 0% to 13.86%. It is estimated that in any given year, there would be approximately 40,000 to 55,000 (0.33% to 0.46%) perioperative strokes nationally.

Conclusions

Our findings support further strategies to identify and stratify patients undergoing surgical procedures with a high incidence of perioperative strokes to improve patient counseling and a future potential treatment plan.

Intermittent streptozotocin administration induces behavioral and pathological features relevant to Alzheimer's disease and vascular dementia

RATIONALE

Diabetes mellitus (DM) is a major risk factor for Alzheimer's disease and vascular dementia. Few animal models exist that focus on the metabolic contributions to dementia onset and progression. Thus, there is strong scientific rationale to explore the effects of streptozotocin (STZ), a diabetogenic compound, on vascular and inflammatory changes within the brain.

OBJECTIVE AND METHODS

The present study was designed to evaluate the effect of staggered, low-dose administration of STZ on behavioral and cognitive deficits, neuroinflammation, tau pathology, and histopathological alterations related to dementia.

RESULTS

Staggered administration (Days 1, 2, 3, 14, 15) of streptozotocin (40 mg/kg/mL) induced a diabetic-like state in mice, resulting in sustained hyperglycemia. STZ-treated animals displayed memory deficits in the novel object recognition task as well as increased tau phosphorylation and increased neuroinflammation. Additionally, STZ led to altered insulin signaling, exhibited by decreased plasma insulin and decreased levels of insulin degrading enzyme and pAKT within the hippocampus.

CONCLUSIONS

STZ-treated animals exhibit cognitive deficits and histopathological changes seen in dementia. This model of dementia warrants continued investigation to better understand the role that DM plays in dementia-related alterations.

A multiscale 0-D/3-D approach to patient-specific adaptation of a cerebral autoregulation model for computational fluid dynamics studies of cardiopulmonary bypass

Neurological complication often occurs during cardiopulmonary bypass (CPB). One of the main causes is hypoperfusion of the cerebral tissue affected by the position of the cannula tip and diminished cerebral autoregulation (CA). Recently, a lumped parameter approach could describe the baroreflex, one of the main mechanisms of cerebral autoregulation, in a computational fluid dynamics (CFD) study of CPB. However, the cerebral blood flow (CBF) was overestimated and the physiological meaning of the variables and their impact on the model was unknown. In this study, we use a 0-D control circuit representation of the Baroreflex mechanism, to assess the parameters with respect to their physiological meaning and their influence on CBF. Afterwards the parameters are transferred to 3D-CFD and the static and dynamic behavior of cerebral autoregulation is investigated. The parameters of the baroreflex mechanism can reproduce normotensive, hypertensive and impaired autoregulation behavior. Further on, the proposed model can mimic the effects of anesthetic agents and other factors controlling dynamic CA. The CFD simulations deliver similar results of static and dynamic CBF as the 0-D control circuit. This study shows the feasibility of a multiscale 0-D/3-D approach to include patient-specific cerebral autoregulation into CFD studies.

Preoperative Stroke and Outcomes after Coronary Artery Bypass Graft Surgery

Background:

Data are lacking on the optimal scheduling of coronary artery bypass grafting (CABG) surgery after stroke. The authors investigated the preoperative predictors of adverse outcomes in patients undergoing CABG, with a focus on the importance of the time interval between prior stroke and CABG.

Methods:

The Hospital Episode Statistics database (April 2006–March 2010) was analyzed for elective admissions for CABG. Independent preoperative patient factors influencing length of stay, postoperative stroke, and mortality, were identified by logistic regression and presented as adjusted odds ratios (OR).

Results:

In all, 62,104 patients underwent CABG (1.8% mortality). Prior stroke influenced mortality (OR 2.20 [95% CI 1.47–3.29]), postoperative stroke (OR 1.99 [1.39–2.85]), and prolonged length of stay (OR 1.31 [1.11–1.56]). The time interval between stroke and CABG did not influence mortality or prolonged length of stay. However, a longer time interval between stroke and CABG surgery was associated with a small increase in risk of postoperative stroke (OR per month elapsed 1.02 [1.00–1.04]; P = 0.047). An interaction was evident between prior stroke and myocardial infarction for death (OR 5.50 [2.84–10.8], indicating the importance of the combination of comorbidities. Prominent effects on mortality were also exerted by liver disease (OR 20.8 [15.18–28.51]) and renal failure (OR 4.59 [3.85–5.46]).

Conclusions:

The authors found no evidence that more recent preoperative stroke predisposed patients undergoing CABG surgery to suffer postoperative stroke, death, or prolonged length of stay. The combination of prior stroke and myocardial infarction substantially increased perioperative risk.

Postoperative brain stroke after shoulder arthroscopy in the lateral decubitus position

The beach chair position is used frequently for shoulder arthroscopy surgery. However, the beach chair position has been reported to be linked to postoperative cerebral stroke. The lateral decubitus position has been used as an alternative position to avoid such neurologic complications. We report a case of postoperative brain stroke in a 52-year-old man who underwent shoulder arthroscopy surgery in the lateral decubitus position. The patient experienced a brief period of intraoperative hypotension. Physicians should be aware of this potential complication that could be irrelevant to the position used.