Novel approach for independent control of brain hypothermia and systemic normothermia: cerebral selective deep hypothermia for refractory cardiac arrest

Neuroprotection in Acute Ischemic Stroke: A Brief Review

The goal of effective neuroprotection in acute ischemic stroke remains elusive. Despite decades of experimental preclinical and clinical experience with innumerable agents, no strategy has proven to be beneficial in humans. As endovascular therapies mature and approach the limits of speed and efficacy, neuroprotection will become the next frontier of acute stroke care. This review will briefly summarize the history, preclinical and clinical triumphs and failures, and future directions of cerebral neuroprotection.

Therapeutic Hypothermia in Acute Ischemic Stroke-a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

Therapeutic hypothermia (TH) in stroke demonstrates robust neuroprotection in animals but clinical applications remain controversial. We assessed current literature on the efficacy of TH in ischemic stroke.

RECENT FINDINGS

We conducted a meta-analysis comparing TH versus controls in studies published until June 2019. Controlled studies reporting on ≥ 10 adults with acute ischemic stroke were included. Primary outcome was functional independence (modified Rankin Scale [mRS] ≤ 2). Twelve studies (n = 351 TH, n = 427 controls) were included. Functional independence did not differ between groups (RR 1.17, 95% CI 0.93-1.46, random-effects p = 0.2). Five studies reported individual mRS outcomes and demonstrated a shift toward better outcome with TH (unadjusted cOR 1.57, 95% CI 1.01-2.44, p = 0.05). Overall complications were higher with TH (RR 1.18, 95% CI 1.06-1.32, p < 0.01). We did not observe an overall beneficial effect of TH in this analysis although some studies showed a shift toward better outcome. TH was associated with increased complications.

Neuroprotection by selective endovascular brain cooling - the TwinFlo™ Catheter

The neuroprotective effects of hypothermia have been demonstrated in experimental models and clinical trials. Experimental studies indicate that improved efficacy and broadened indications can be achieved with moderate to deep hypothermia. The TwinFlo catheter was designed to provide very rapid, deep and selective brain cooling with faster cooling rates, and temperatures much lower than those which can be achieved by any other hypothermia device and technique. This report describes the experimental in vivo studies and initial clinical experience with the TwinFlo catheter.

Selective retrograde cerebral cooling in complete cerebral circulatory arrest

BACKGROUND AND PURPOSE:

Cerebral hypothermia is a known neuroprotectant with promising applications in the treatment of ischemic events. Although systemic cooling is standard in post-cardiac arrest care, the deleterious effects of whole-body cooling have precluded it from translation into a viable treatment option for acute ischemic stroke (AIS). Selective cerebral cooling has been proposed as a method to minimize these risks while granting the neuroprotection of therapeutic hypothermia in AIS.

METHODS:

In a porcine model (n = 3), the efficacy of selective retrograde cerebral cooling through the internal jugular vein was evaluated in the setting of complete cerebral circulatory arrest. Furthermore, a novel endovascular device and cooling system enabling selective retrograde cerebral cooling were studied in a normothermic perfused cadaver.

RESULTS AND CONCLUSION:

Neurologic assessment of animals receiving this therapy reflected substantial neuroprotection in animals undergoing both 15 min and 30 min of otherwise catastrophic complete cerebral circulatory arrest. The novel endovascular device and cooling system were validated in human anatomy, demonstrating successful cerebral cooling, and feasibility of this mechanism of selective retrograde cerebral cooling.

Therapeutic hypothermia: Applications in adults with acute ischemic stroke

The advent of mechanical thrombectomy and increasing alteplase use have transformed the care of patients with acute ischemic stroke. Patients with major arterial occlusions with poor outcomes now have a chance of returning to independent living in more than half of the cases. However, many patients with these severe strokes suffer major disability despite these therapies. The search is ongoing for agents that can be combined with thrombectomy to achieve better recovery through halting infarct growth and mitigating injury after ischemic stroke. Several studies in animals and humans have demonstrated that therapeutic hypothermia (TH) offers potential to interrupt the ischemic cascade, reduce infarct volume, and improve functional independence. We performed a literature search to look up recent advances in the use of TH surrounding the science, efficacy, and feasibility of inducing TH in modern stroke treatments. While protocols remain controversial, there is a real opportunity to combine TH with the existing therapies to improve outcome in adults with acute ischemic stroke.

Effect of interplay between age and low-flow duration on neurologic outcomes of extracorporeal cardiopulmonary resuscitation

Purpose

Caseloads of extracorporeal cardiopulmonary resuscitation (ECPR) have increased considerably, and hospital mortality rates remain high and unpredictable. The present study evaluated the effects of the interplay between age and prolonged low-flow duration (LFD) on hospital survival rates in elderly patients to identify subgroups that can benefit from ECPR.

Methods

Adult patients who received ECPR in our institution (2006–2016) were classified into groups 1, 2, and 3 (18–65, 65–75, and > 75 years, respectively). Data regarding ECPR and adverse events during hospitalization were collected prospectively. The primary end point was favorable neurologic outcome (cerebral performance category 1 or 2) at hospital discharge.

Results

In total, 482 patients were divided into groups 1, 2, and 3 (70.5%, 19.3%, and 10.2%, respectively). LFDs were comparable among the groups (40.3, 41.0, and 44.3 min in groups 1, 2, and 3, P = 0.781, 0.231, and 0.382, respectively). Favorable neurologic outcome rates were nonsignificantly lower in group 3 than in the other groups (27.6%, 24.7%, and 18.4% for group 1, 2, and 3, respectively). Subgroup analysis revealed that the favorable neurologic outcome rates in group 1 were 36.7%, 25.4%, and 13.0% for LFDs of < 30, 30–60, and > 60 min, respectively (P = 0.005); in group 2, they were 32.1%, 21.2%, and 23.1%, respectively (P = 0.548); in group 3 they were 25.0%, 20.8%, and 0.0%, respectively (P = 0.274).

Conclusion

On emergency consultation for ECPR, age and low-flow duration should be considered together to predict neurologic outcome.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5496-y) contains supplementary material, which is available to authorized users.