Emergency extracranial-intracranial bypass surgery for acute ischemic stroke

Delayed microsurgical revascularization in an acute ischemic stroke based on perfusion study

A 58-year-old patient presented with a severe neurological deficit due to a stroke caused by an occlusion of the left internal carotid artery siphon. Standard treatment failed and neurosurgical consult was delayed. Because of a favorable perfusion imaging finding, microsurgical revascularization via an extra-intracranial bypass (left superficial temporal artery - left middle cerebral artery) was performed 36 hours after the onset of the symptoms. The outcome of the patient was favorable. The authors want to emphasize the need to actively seek patients with a severe neurological deficit and still viable brain tissue. The time window and treatment alternatives are discussed.

Long-term outcomes and quantitative radiologic analysis of extracranial-intracranial bypass for hemodynamically compromised chronic large artery occlusive disease

This study aimed to demonstrate the effectiveness of nonemergent extracranial-to-intracranial bypass (EIB) in symptomatic chronic large artery atherosclerotic stenosis or occlusive disease (LAA) through quantitative analysis of computed tomography perfusion (CTP) parameters using RAPID software. We retrospectively analyzed 86 patients who underwent nonemergent EIB due to symptomatic chronic LAA. CTP data obtained preoperatively, immediately postoperatively (PostOp0), and 6 months postoperatively (PostOp6M) after EIB were quantitatively analyzed through RAPID software, and their association with intraoperative bypass flow (BF) was assessed. The clinical outcomes, including neurologic state, incidence of recurrent infarction and complications, were also analyzed. The time-to-maximum (Tmax) > 8 s, > 6 s and > 4 s volumes decreased significantly at PostOp0 and up through PostOp6M (preoperative, 5, 51, and 223 ml (median), respectively; PostOp0, 0, 20.25, and 143 ml, respectively; PostOp6M, 0, 7.5, and 148.5 ml, respectively; p < 0.001, p < 0.001, and p < 0.001, respectively). The postoperative improvement in the Tmax > 6 s and > 4 s volumes was significantly correlated with the BF at PostOp0 and PostOp6M (PostOp0, r = 0.367 (p = 0.001) and r = 0.275 (p = 0.015), respectively; PostOp6M r = 0.511 (p < 0.001) and r = 0.391 (p = 0.001), respectively). The incidence of recurrent cerebral infarction was 4.7%, and there were no major complications that produced permanent neurological impairment. Nonemergent EIB under strict operation indications can be a feasible treatment for symptomatic, hemodynamically compromised LAA patients.

Quantitative radiological analysis and clinical outcomes of urgent EC-IC bypass for hemodynamic compromised patients with acute ischemic stroke

This study aimed to demonstrate the effectiveness of urgent extracranial-to-intracranial bypass (EIB) in acute ischemic stroke (AIS) through quantitative analysis of computed tomography perfusion (CTP) results using RAPID software. We retrospectively analyzed 41 patients who underwent urgent EIB for AIS under strict operation criteria. The quantitative data from CTP images were reconstructed to analyze changes in pre- and postoperative perfusion status in terms of objective numerical values using RAPID software. Short- and long-term clinical outcomes, including complications and neurological status, were also analyzed. Postoperatively, the volume of time-to-max (Tmax) > 6 s decreased significantly; it continued to improve significantly until 6 months postoperatively (preoperative, 78 ml (median); immediate postoperative, 23 ml; postoperative 6 months, 7 ml; p = 0.000). Ischemic core-penumbra mismatch volumes were also significantly improved until 6 months postoperatively (preoperative, 72 ml (median); immediate postoperative, 23 ml; postoperative 6 months, 5 ml; p = 0.000). In addition, the patients' neurological condition improved significantly (p < 0.001). Only one patient (2.3%) showed progression of infarction. Urgent EIB using strict indications can be a feasible treatment for IAT-ineligible patients with AIS due to large vessel occlusion or stenosis.

Emergency extra-intracranial bypass surgery in a patient with neurologic deficit after an accident in carotid occlusive test: A case report

OBJECTIVE

BTO is the procedure performed to assess the collateral circulation within the Willis circle in a giant ICA aneurysm. An ICA occlusion after BTO is very rare. We present a case of an internal carotid artery occlusion as a complication of BTO that required urgent revascularization surgery.

CASE PRESENTATION

A 56-year-old female with a history of transient ischemic attacks for one year was diagnosed with multiple aneurysms: a giant aneurysm of the left supra-clinoid ICA, two small ones on left MCA and right ophthalmic. A BTO was performed to assess collateral supply and determine whether bypass surgery should be necessary. During the procedure, the balloon was detached while insufflating, and the patient had a subsequent neurological decline consistent with an MCA syndrome. EC-IC bypass surgery was performed with an end-to-side anastomosis of STA-MCA by trapping the giant aneurysm and clipping the ipsilateral MCA aneurysm. The patient had a reversal of neurological symptoms and made an uneventful recovery.

DISCUSSION

We discuss the epidemiology of giant ICA aneurysms, the indications for BTO, and its complication. Emergency intracranial and extracranial bypass surgery in case of acute ICA injury is also discussed. We also highlighted the attributable factors to treatment strategies under restrictive conditions in Vietnam.

CONCLUSIONS

ICA occlusion due to insufflated balloon detachment is an unreported complication in literature. Emergency bypass surgery is a potential treatment choice for this unusual iatrogenic complication.

Ischemic Stroke Revascularization

Extracranial-intracranial (EC-IC) bypass is one of the most fundamental techniques for ischemic cerebrovascular disease (CVD). We describe the standard surgical strategies, advanced techniques, and controversies concerning revascularization of ischemic stroke. The standard surgical strategies and techniques emphasize how to determine surgical indication, which should be decided for symptomatic internal carotid artery or middle cerebral artery (MCA) occlusive disease with misery perfusion detected by quantitative single photon emission computed tomography. Advanced techniques are available for complex situations such as posterior circulation revascularization, Bonnet bypass for common carotid artery obstruction, and various EC-IC bypasses for ischemia in the MCA and/or anterior cerebral artery territories using inter-grafts such as femoral veins and radial arteries, illustrated by our surgical results and experiences. Controversies include endovascular treatment complementary to EC-IC bypass. Finally, we advocate emergent EC-IC bypass for progressive ischemic CVD, particularly for contraindication or unsuccessful treatment after intravenous tissue plasminogen activator administration and/or endovascular thrombolysis. EC-IC bypass surgery can be reliable for ischemic CVD under strict optimal surgical indications using safe and reliable surgical techniques.

Short-Vessel Occlusion Might Indicate Higher Possibility of Success in Reperfusion following Mechanical Thrombectomy in Acute Middle Cerebral Artery Occlusion

BACKGROUND

The impact of the length of the occluded vessel in acute large-vessel occlusion on successful reperfusion by mechanical thrombectomy remains unclear. This study evaluated whether diameter and length of the occluded vessel in acute middle cerebral artery (MCA) occlusion might relate to successful reperfusion following mechanical thrombectomy.

METHODS

This retrospective study included patients with acute MCA occlusion who underwent intra-aortic injection of contrast medium to obtain maximum intensity projection (MIP) images acquired by flat-panel detector computed tomography (FD-CT) equipped with an angiographic system. All patients received mechanical thrombectomy and were divided into two groups: those with successful reperfusion (Thrombolysis in Cerebral Infarction [TICI] 2b/3) and those without. We compared the diameter and length of the occluded vessel between the groups. In the sub-analysis of patients with stent retriever use, ratio of length of occluded vessel to length of the active zone was compared.

RESULTS

We enrolled 29 patients (median age: 73, M1 occlusion: 51%, stent retriever use: 72%). Eighteen patients achieved TICI 2b/3 with significantly larger distal end diameter (1.7 [interquartile range: 1.5-1.9] vs. 1.2 [1.2-1.5] mm, p = 0.007) and shorter length (7.1 [4.9-9.7] vs. 12.3 [7.2-15.8] mm, p = 0.043) of the occluded vessel. Sub-analysis of 21 patients showed that the cut-off value for TICI 2b/3 reperfusion was 0.32 as the ratio between the occluded vessel and stent retriever active zone (receiver operating characteristic area under the curve: 0.90).

CONCLUSION

In acute MCA occlusion, larger diameter of the distal end and shorter length of the occluded vessel on FD-CT MIP images might indicate a higher possibility of achieving TICI 2b/3 following mechanical thrombectomy.

Trends in Literature on Cerebral Bypass Surgery: A Systematic Review

INTRODUCTION

Ever since the beginning of cerebral bypass surgery, the role of the bypass has been debated and indications have changed over the last 5 decades. This systematic literature research analysed all clinical studies on cerebral bypass that have been published from January 1959 to January 2020 for their year of publication, country of origin, citation index, role of and indication for bypass, bypass technique, revascularized territory, flow capacity, and title (for word cloud analysis per decade).

METHODS

A systematic literature research was conducted using PubMed, Web of Science, EMBASE, and SCOPUS databases. All studies that have been published until January 1, 2020, were included.

RESULTS

Of 6,013 identified studies, 2,585 were included in the analysis. Of these, n = 1,734 (67%) studies addressed flow-augmentation bypass and n = 701 (27%) addressed flow-preservation bypass. The most common indication reported for flow augmentation is moyamoya (n = 877, 51%), followed by atherosclerotic steno-occlusive disease (n = 753, 43%). For flow preservation, the most common indication is studies reporting on cerebral aneurysm surgery (n = 659, 94%). The increasing popularity of reporting on these bypass operations almost came to an end with the FDA approval of flow diverters for aneurysm treatment in 2011. Japan is the country with the most bypass studies (cumulatively published 933 articles), followed by the USA (630 articles) and China (232 articles).

DISCUSSION/CONCLUSION

Clinical studies on cerebral bypass surgery have become increasingly popular in the past decades. Since the introduction of moyamoya as a distinct pathologic entity, Asian countries in particular have a very active community regarding this disease, with an increasing number of articles published every year. Studies on bypass for chronic steno-occlusive disease peaked in the 1980s but have remained the main focus of bypass research, particularly in many European departments. The number of reports published on these bypass operations significantly decreased after the FDA approval of flow diverters for aneurysm treatment in 2011.

Agreement of novel hemodynamic imaging parameters for the acute and chronic stages of ischemic stroke: a matched-pair cohort study

OBJECTIVE

In symptomatic patients with cerebrovascular steno-occlusive disease, impaired blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) and increased flow velocity of the P2 segment of the posterior cerebral artery (PCA-P2) on transcranial Doppler (TCD) ultrasonography have been introduced as emerging clinical imaging parameters to identify patients at high risk for recurrent ischemic events. Since hemodynamic physiology differs between the acute and chronic stages of ischemic stroke, the authors sought to investigate whether those parameters have merit for both the acute and chronic stages of ischemic stroke.

METHODS

From a prospective database, patients who underwent BOLD-CVR and TCD examinations in the acute stroke stage (< 10 days) were matched to patients in the chronic stroke stage (> 3 months). A linear regression analysis for both groups was performed between ipsilateral PCA-P2 systolic flow velocity and BOLD-CVR of the ipsilateral (affected) hemisphere, the ipsilateral middle cerebral artery (MCA) territory, and the ipsilateral steal volume (i.e., paradoxical BOLD-CVR response). The resulting slopes and intercepts were statistically compared to evaluate differences between groups.

RESULTS

Forty matched patient pairs were included. Regression analysis showed no significant difference for either the intercept (p = 0.84) or the slope (p = 0.85) between PCA-P2 flow velocity and BOLD-CVR as measured for the ipsilateral (affected) hemisphere. Similarly, no significant difference was seen between PCA-P2 flow velocity and BOLD-CVR of the ipsilateral MCA territory (intercept, p = 0.72; slope, p = 0.36) or between PCA-P2 flow velocity and steal volume (intercept, p = 0.59; slope, p = 0.34).

CONCLUSIONS

The study results indicated that the relationship between ipsilateral PCA-P2 systolic flow velocity and BOLD-CVR remains the same during the acute and chronic stages of ischemic stroke. This provides further support that these novel hemodynamic imaging parameters may have merit to assess the risk for recurrent ischemic events for a wide ischemic stroke population. PCA-P2 systolic flow velocity, in particular, may be a highly practical screening tool, independent of ischemic stroke stage.

A 1-Donor 2-Recipient Superficial Temporal Artery-Middle Cerebral Artery Bypass for Moyamoya Syndrome: 2-Dimensional Operative Video

We present the case of a 34-yr-old male who suffered repeated ischemic events resulting in right-sided weakness. He was found to have left M1 segment near occlusion on angiography with a large area of uncompensated hypoperfusion. The patient underwent a direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Direct bypass in the acute setting of ischemia has been previously described.1-5 Moyamoya ischemic disease can be treated with either direct or indirect surgical revascularization. There have been several techniques developed for direct bypasses in moyamoya ischemic disease. These include the standard 1-donor 1-recipient (1D1R) end-to-side (ES) bypass, the "double-barrel" 2-donor 2-recipient (2D2R) ES bypass, and the more recently developed 1-donor 2-recipient (1D2R)6,7 utilizing both an ES and a side-to-side (SS) bypass with a 1-donor vessel. The case presentation, surgical anatomy, decision-making, operative nuances, and postoperative course and outcome are reviewed. The patient gave verbal consent for participating in the procedure and surgical video.

Efficacy and Safety of Timely Urgent Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Surgery in Patients with Acute Ischemic Stroke: A Single-Institutional Prospective Study and a Pooled Analysis

BACKGROUND

Clinical outcome in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is not satisfactory if reperfusion treatment fails or is not tried.

AIMS

We aimed to assess the efficacy and safety of urgent superficial temporal-to-middle cerebral artery (STA-MCA) bypass surgery in selected patients.

METHODS

Patients who were diagnosed with LVO-induced AIS in the anterior circulation but had a failed intra-arterial thrombectomy (IAT) or were not tried due to IAT contraindications were prospectively enrolled. Timely urgent STA-MCA bypass surgery was performed if they showed perfusion-diffusion mismatch or symptom-diffusion mismatch in the acute phase of disease. Clinical and radiological data of these patients were assessed to demonstrate the safety and efficacy of urgent bypass procedures. A pooled analysis of published data on urgent bypass surgery in acute stroke patients was conducted and analyzed.

RESULTS

In 18 patients who underwent timely bypass, the National Institutes of Health Stroke Scale (NIHSS) score improved from 12.11 ± 4.84 to 9.89 ± 6.52, 1 week after surgery. Three-month and long-term (9.72 ± 5.00 months) favorable outcomes (modified Rankin Scale [mRS] scores 0-2) were achieved in 50 and 75% of the patients, respectively. The pooled analysis (117 patients from 10 articles, including ours) identified favorable mRS scores in 71.79% patients at 3 months. A significant NIHSS score improvement from 11.51 ± 4.89 to 7.59 ± 5.50 was observed after surgery with significance. Major complications occurred in 3 patients (2.6%, 3/117) without mortality.

CONCLUSIONS

Urgent STA-MCA bypass surgery can be regarded as a safe optional treatment to prevent cerebral infarct expansion and to improve clinical and radiological outcomes in highly selected patients.

Flow-augmentation bypass in the treatment of acute ischemic stroke

INTRODUCTION

Results of two randomized trials did not show benefit of revascularization with extracranial-intracranial (EC-IC) flow augmentation bypass in patients with symptomatic occlusion of internal carotid artery (ICA). However, patients with acute stroke were not included in these studies. Herein, we systematically analyze and discuss the literature about flow augmentation bypass for treatment of acute ischemic stroke.

EVIDENCE ACQUISITION

This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were independently searched by two reviewers for published series to identify literature relating to EC-IC bypass in the surgical management of acute ischemic stroke up to June 2020. Studies were categorized according to their level of evidence.

EVIDENCE SYNTHESIS

Nineteen studies met the inclusion criteria for the systematic literature review, including 16 level IV studies (ten case series and six6 case reports) and three level III studies (retrospective cohort case-control studies). Occurrence of fatal or non-fatal ischemic or hemorrhagic postoperative stroke, as well as clinical functional outcome at follow-up were considered as primary and secondary endpoints, respectively.

CONCLUSIONS

The literature about flow augmentation bypass for treatment of acute ischemic stroke is scarce and heterogenous, with only 19 studies. The results of the present systematic review encourage further study to explore and validate the use of EC-IC bypass in the treatment of anterior circulation acute ischemic stroke in highly selected patients (symptomatic and with persistent penumbra despite best medical/endovascular treatment).

Safety and clinical outcomes of urgent superficial temporal artery-middle cerebral artery bypass-a single-institution retrospective analysis

BACKGROUND

Intravenous recombinant tissue-type plasminogen activator (rt-PA) with/without endovascular treatment is sometimes not ideally effective for the treatment of acute hemodynamic stroke due to atherosclerotic major artery steno-occlusive disease, and some patients show fluctuation in or progression of symptoms despite intensive medical therapy. Urgent superficial temporal artery-middle cerebral artery (STA-MCA) bypass has been reported to be effective in patients with progressing stroke.

OBJECTIVE

To investigate the efficacy of urgent STA-MCA bypass performed at a single institution for progressing stroke due to hemodynamic compromise caused by atherosclerosis.

METHOD

We retrospectively reviewed clinical and operative records. Neurological outcomes were assessed with the modified Rankin Scale (mRS) with consideration of patient age: more than 2 points on the mRS was regarded as a poor outcome in patients under 80 years old, and more than 3 points was considered a poor outcome in those over 80 years old. The risk factors contributing to poor outcomes were evaluated.

RESULTS

From 2008 to 2017, 35 patients underwent urgent STA-MCA bypass for progressing stroke. The average patient age was 70.4 years (range 49-96 years). The mean National Institutes of Health Stroke Scale (NIHSS) score was 5.1 (range 0-24 points) on admission and 7.8 before surgery. After 3 months, 25 patients showed good outcomes. The preoperative NIHSS score contributed to a poor outcome (odds ratio 1.65 (95% confidence interval 1.12-2.90)).

CONCLUSIONS

Urgent STA-MCA bypass is a treatment option for patients with progressing stroke. The operation should be performed while the NIHSS score is low.

Early versus Delayed Extracranial-Intracranial Bypass Surgery in Symptomatic Atherosclerotic Occlusion

BACKGROUND

Clinical trials of extracranial-intracranial (EC-IC) bypass surgery studied patients in subacute and chronic stage after ischemic event.

OBJECTIVE

To investigate the short-term outcomes of EC-IC bypass in progressive acute ischemic stroke or recent transient ischemic attacks.

METHODS

The study was a retrospective review at a single tertiary referral center from 2008 to 2015. Inclusion criteria consisted of EC-IC bypass within 1 yr of last ischemic symptoms ipsilateral to atherosclerotic occlusion of internal carotid or middle cerebral artery. Early bypass group who underwent surgery within 7 d of last ischemic symptoms were compared to late bypass group who underwent surgery >7 d from last ischemic symptom. The primary endpoint was perioperative ischemic or hemorrhagic stroke or intracranial hemorrhage within 7 d of surgery.

RESULTS

Of 126 patients who underwent EC-IC bypass during the period, 81 patients met inclusion criteria, 69 (85%) persons had carotid artery occlusion, 7 (9%) had proximal MCA occlusion, and 5 (6%) had both. Early surgery had a 31% (9/29) perioperative stroke rate compared to 11.5% (6/52) of patients undergoing late bypass (P = .04). Of patients with acute stroke within 7 d of surgery, 41% (7/17) had perioperative stroke within 7 d (P = .07). Six of nine patients (67%) with blood pressure dependent fluctuation of neurologic symptoms had perioperative stroke (P = .049).

CONCLUSION

EC-IC bypass in setting of acute symptomatic stroke within 1 wk may confer higher risk of perioperative stroke. Patients undergoing expedited or urgent bypass for unstable or fluctuating stroke symptoms might be at highest risk for perioperative stroke.

When the fat hits the brain-salvage STA-MCA bypass for an intracranial ICA occlusion due to a fat embolus

BACKGROUND

Large fat embolus is a rare but potential reversible cause of ischaemic stroke.

METHODS AND RESULTS

We describe the neurosurgical management of a complete right internal carotid artery occlusion due to a large fat embolus, caused by a mitral valve replacement.

CONCLUSION

Knowledge of acute cerebral ischaemia due to large fat embolism and its hallmark 'hypodense artery' is mandatory. Extracranial to intracranial bypass is a feasible rescue treatment after failure of endovascular embolectomy.

Local in situ fibrinolysis for recanalization of an occluded extracranial-intracranial bypass: Technical note

Extracranial-intracranial (EC-IC) bypass is a versatile technique to augment or preserve blood flow when treating cerebrovascular pathologies to prevent ischemic complications. Technical success and good patient outcomes rely on the successful establishment and maintenance of a patent bypass graft. Multiple modalities have been developed to confirm intraoperative graft patency. However, techniques and strategies to manage an occluded bypass are sparsely reported. The authors describe a novel technique for the in situ fibrinolysis utilizing recombinant tissue plasminogen activator (r-tPA) to recanalize an occluded EC-IC bypass following thrombus formation. This technique is feasible and effective in restoring long term EC-IC graft patency without requirement of additional vessel harvest or added ischemia time which may be tailored for use with other pharmacologic agents based on the acuity of an in-graft thrombosis.

Unexpected immediate postoperative resolution of long-standing neurological deficits following extracranial-intracranial bypass: a report of three cases

While intracranial ischemic insults often result in neuronal death and permanent neurological deficits, some patients may develop potentially reversible neurological dysfunction from persistent hypoperfusion, as surviving neurons remain in an "idling" state. We report a unique series of three patients with long-standing neurological deficits who underwent EC-IC bypass for repeated TIAs and demonstrated unexpected, rapid resolution of long-standing pre-existing neurological deficits. We suggest that these individuals harbored regions of underperfused, idling neurons that responded rapidly to restored cerebral reperfusion.

Bypass Surgery for Ischemic Stroke Caused by Intracranial Artery Stenosis or Occlusion

Surgical revascularization may be beneficial in patients with ischemic stroke caused by intracranial stenosis or occlusion who are ineligible for thrombolysis.

Objective

To evaluate the outcome of superficial temporal artery to middle cerebral artery (STA-MCA) bypass in ischemic stroke caused by intracranial artery stenosis or occlusion.

Methods

We retrospectively studied successive case series of 19 patients who underwent surgical treatment between 2013–2017 of STA-MCA bypass. Surgical procedure was performed for the patients with acute ischemic stroke who were ineligible for thrombolysis.

Results

Of the 19 patients enrolled, symptom aggravation occurred during medical treatment, the patients were ineligible for thrombolysis despite being within 8 hours of symptom onset. Bypass significantly improved National Institutes of Health Stroke Scale scores, mean patient age was 78.05 years (range, 39–78 y). However, male 11 (57.95%) out of nineteen patients were presented with left-sided-lesions while female 8 (42%) had right-sided lesions with significant infarction growth by diffusion weighted imaging achieved, after surgical maneuver. No major complications occurred intraoperatively, in contrast to 2 (10.5%) minor manifestation were suffering minor complications probably they included the remote infarction (posterior cerebral artery territory). Pooled analysis with our patients showed a significant neurological improvement and a good outcome in 13 (68.4%) patients without hemorrhage or any other complication, 6 (31.6%) patients with unfavorable outcome (severe disability 2; vegetative state 4, non of them are died 0;).

Conclusion

STA-MCA bypass may be beneficial to patients with acute stroke or stenosis in progress who are ineligible for medical therapy. Furthermore, it appears safe when the infarction is small. These findings indicate that STA-MCA bypass could be considered as a treatment option in selected patients with ischemic stroke caused by intracranial stenosis or occlusion.

Safety of urgent STA-MCA anastomosis after intravenous rt-PA treatment: a report of five cases and literature review

BACKGROUND

Intravenous recombinant tissue-type plasminogen activator (rt-PA) with/without endovascular treatment is not as effective in atherosclerotic steno-occlusive acute ischemic stroke. Urgent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis is effective to some extent in progressing stroke, but the safety of STA-MCA anastomosis soon after rt-PA therapy is unknown. Our aim was to clarify the safety of STA-MCA anastomosis within 24 h after intravenous rt-PA.

METHOD

From 2005 to 2015, rt-PA was administered to 225 patients presenting with acute ischemic stroke according to the Japanese Stroke Guidelines, in our institution. Five patients underwent urgent STA-MCA anastomosis after rt-PA administration with or without endovascular recanalization. Clinical time course, surgical complications, and patients' prognosis were investigated.

RESULTS

The average of patient age was 65.4 years (range 49-77 years); three patients had internal carotid artery occlusion, and two patients had middle cerebral artery occlusion. The median National Institutes of Health Stroke Scale score on admission was 12.4 (range 6-17 points) and operation occurred 10.6 h (range 5.3-23.6 h) after intravenous rt-PA administration. Hemostasis was achieved during standard STA-MCA anastomosis, and there were no hemorrhagic complications.

CONCLUSIONS

In our consecutive cases, urgent STA-MCA anastomosis after at least 5.3 h after intravenous rt-PA was performed safely without hemorrhagic complications.

Usefulness of intraoperative Indocyanine green video angiography to select the recipient artery for bypass surgery in arteriosclerotic occlusion of the middle cerebral artery: a technical case report

BACKGROUND

In superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass surgery, indocyanine green video angiography (ICG-VA) is usually used to verify bypass patency. Less-commonly reported is the ability to use this technique to evaluate candidate recipient vessels based on either collateral flow or identification of the distal branch of interest.

CASE PRESENTATION

An 82-year-old man presented with progressive cerebral infarction due to infarction of the M2 inferior trunk of the right middle cerebral artery. He underwent superficial temporal artery-middle cerebral artery bypass to prevent further ischemia 1 week after the initial stroke. In the surgery, M4 cortical arteries fed by the inferior trunk could not be identified as recipient arteries. Intraoperative ICG-VA showed delayed luminescence of some M4 arteries. Because the M4 arteries fed by the inferior trunk showed delayed retrograde flows from the anterior cerebral artery on preoperative digital subtraction angiography, the M4 arteries with delayed luminescence on ICG-VA were considered to be M4 arteries fed by the inferior trunk and selected as the recipient arteries.

CONCLUSIONS

ICG-VA shows differences in flow speed as delayed luminescence. This finding may be useful for detecting target vessels.

Revision Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery for Recurrent Acute Ischemic Stroke Due to Delayed Occlusion of the Bypass Graft

Intravenous thrombolysis (IVT) and endovascular treatment (EVT) are currently the main treatments for reperfusion in acute ischemic stroke. Although the EVT recanalization rate has increased, unsuccessful recanalization is still observed in 10-30% cases. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass is considered a rescue therapy in such cases, but in most centers it is not usually performed for acute ischemic stroke. Graft occlusion is rare following STA-MCA bypass, but it might lead to recurrent ischemic stroke. We hereby report on a patient with right MCA infarction and in whom EVT failed due to complete proximal internal carotid artery occlusion. He underwent an emergency STA-MCA bypass, resulting in a full recovery of his motor weakness. However, six months later, the patient experienced recurrent acute ischemic stroke due to bypass graft occlusion. His EVT failed again but revision bypass surgery, using STA remnant branch, was successful with full motor weakness recovery. We recommend a revision bypass surgery as a feasible therapeutic option for recurrent cerebral infarction caused by delayed STA graft occlusion.

Mechanical thrombectomy - is time still brain? The DAWN of a new era

PURPOSE

The purpose of this study is to review the history of treatments for acute ischemic stroke, examine developments in endovascular therapy, and discuss the future of the management of acute ischemic stroke.

METHODS

A selective review of recent clinical trials for the treatment of acute ischemic stroke was conducted.

RESULTS

We reviewed completed trials of the management of acute ischemic stroke including intravenous thrombolytics, intraarterial thrombolytics, and thrombectomy. We also assessed the future direction of research by reviewing ongoing clinical trials.

CONCLUSIONS

The advancement of endovascular treatment for stroke has led to improved morbidity and mortality for patients. Future challenges include delivering these treatments to stroke centers worldwide.

Patient Selection and Clinical Efficacy of Urgent Superficial Temporal Artery-Middle Cerebral Artery Bypass in Acute Ischemic Stroke Using Advanced Magnetic Resonance Imaging Techniques

BACKGROUND: Selected patients with acute ischemic stroke might benefit from superficial temporal artery-middle cerebral artery (STA-MCA) bypass, but the indications for urgent STA-MCA bypass are unknown.

OBJECTIVE: To report our experiences of urgent STA-MCA bypass in patients requiring urgent reperfusion who were ineligible for other reperfusion therapies, using advanced magnetic resonance imaging (MRI) techniques.

METHODS: The inclusion criteria for urgent STA-MCA bypass were as follows: acute infarct volume &lt;70 mL with a ratio of perfusion/diffusion lesion volume ≥1.2, and a regional cerebral blood volume ratio &gt;0.85. From January 2013 to October 2015, 21 urgent STA-MCA bypass surgeries were performed. The control group included 19 patients who did not undergo bypass surgery mainly due to refusal of surgery or the decision of the neurologist. Clinical and radiological data were compared between the surgery and control group.

RESULTS: The median age of the control group (70 years, interquartile range [IQR] 58-76) was higher than that of the surgery group (62 years, IQR 49-66), but the median preoperative diffusion and perfusion lesion volumes of the surgery group (13.8 mL, IQR 7.5-26.0 and 120.9 mL, IQR 84.9-176.0, respectively) were higher than those of the control group (5.6 mL, IQR 2.1-9.1 and 69.7 mL, IQR 23.9-125.3, respectively). Sixteen (76.2%) patients in the surgery group and 2 (10.5%) patients in the control group had favorable outcomes (P &lt; .001). Logistic regression analysis identified bypass surgery as the strongest predictive factor.

CONCLUSION: STA-MCA bypass can be used as a therapeutic tool for acute ischemic stroke. Advanced MRI techniques are helpful for selecting patients and for decision making.

Efficacy of Early Superficial Temporal Artery-Middle Cerebral Artery Double Anastomoses for Atherosclerotic Occlusion in Patients with Progressing Stroke

BACKGROUND

We investigated the efficacy of early superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses for patients with progressing stroke due to atherosclerotic occlusion.

MATERIALS AND METHODS

Nine consecutive patients who underwent early STA-MCA double anastomoses were enrolled. All patients presented with progressing stroke despite maximal medical treatment. Cerebral blood flow in 7 patients was analyzed by single-photon emission tomography. Clinical outcomes were investigated postoperatively, and we evaluated the utility of early STA-MCA double anastomoses.

RESULTS

Nine patients in the present study included those with middle cerebral artery occlusion (n = 6) and internal carotid artery occlusion (n = 3). The mean age was 58.4 years. Subjects comprised 1 female (11.1%) and 8 males (88.9%). The cause was low perfusion ischemia due to atherosclerotic occlusion with a small infarct. The mean regional cerebral blood flow (rCBF) ratio in the middle cerebral artery territory compared to the normal side was 69.6 ± 5.3%. The duration from onset to surgery was 1-8 days (median, 3.11 days). All patients underwent early STA-MCA double anastomoses, and no reperfusion-induced hemorrhage occurred. All of them slowly achieved obvious remission compared to symptoms on admission and achieved a good functional outcome.

CONCLUSIONS

Early STA-MCA double anastomoses were safe and effective, and early revascularization resulted in rapid neurological improvement. We recommend this procedure for patients with progressive ischemia due to main trunk artery occlusion, when the rCBF flow ratio with the normal side was 70 ± 10%, even at the subacute stage.

Emergent Double-barrel Bypass Shortly after Intravenous Administration of Recombinant Tissue Plasminogen Activator for Acute Ischemic Stroke

Although intravenous recombinant tissue plasminogen activator (IV rt-PA) is effective in many cases of acute ischemic stroke, the neurologic symptoms can worsen after IV rt-PA because of sustained vessel occlusion. For such cases, several reperfusion modalities are available, including intra-arterial thrombolysis (IAT), carotid endarterectomy, and superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Invasive procedures, such as major surgery, should be generally avoided within 24 hours after the administration of IV rt-PA. A 66-year-old man with no previous medical history developed left hemiparesis. A computed tomography scan revealed no acute lesion and he received IV rt-PA within 1.5 hours after symptom onset. Emergent magnetic resonance imaging showed significant diffusion-perfusion mismatch. He received IAT 2 hours after IV rt-PA administration, but IAT failed because of total occlusion of the cervical internal carotid artery. We initially planned to perform STA-MCA bypass the next morning because he had received IV rt-PA, but, 8 hours after IV rt-PA administration, his hemiparesis worsened from motor grade 3/4 to motor grade 1/2. Because of the large perfusion defect in both MCA divisions, double-barrel STA-MCA bypass was performed 10 hours after IV rt-PA administration. His symptoms rapidly improved after surgery and his modified Rankin Scale score 3 months later was grade 0. We suggest that emergent double-barrel bypass can be a viable option in patients who have perfusion defects of both MCA divisions in acute ischemic stroke after IV rt-PA administration.

Perfusion-Weighted MRI Parameters for Prediction of Early Progressive Infarction in Middle Cerebral Artery Occlusion

Objective

Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI.

Methods

We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ≥2 points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI.

Results

Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55–24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4–30.27) was significantly correlated with EPI.

Conclusion

The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

Emergent surgical embolectomy in conjunction with cervical internal carotid ligation and superficial temporal artery-middle cerebral artery bypass to treat acute tandem internal carotid and middle cerebral artery occlusion due to cervical internal carotid artery dissection

Background:

Acute tandem cervical dissecting internal carotid artery (ICA) occlusion and intracranial embolic middle cerebral artery (MCA) occlusion can be devastating, and the optimal treatment strategy for this condition has not been established yet.

Case Description:

A 45-year-old male presented with aphasia and right hemiparesis preceded by neck pain. Computed tomography showed a high-density signal along the left MCA, suggesting extensive emboli. Magnetic resonance angiography demonstrated tandem occlusion of the left cervical ICA and intracranial MCA with minimal diffusion-weighted imaging lesion. Emergent surgical embolectomy was performed, and long intracranial MCA emboli were retrieved with collateral cross-flow restoration. The cervical ICA was exposed, and dissection was confirmed. The cervical ICA was ligated, and superficial temporal artery (STA)-MCA anastomosis was added. Postoperatively, the patient demonstrated recovery from right hemiparesis and aphasia. At the 6^th postoperative month, follow-up studies demonstrated a robustly patent STA-MCA bypass and no additional ischemic lesion on T2-weighted imaging.

Conclusions:

Surgical embolectomy in conjunction with ligation of the cervical ICA followed by STA-MCA bypass might be a safe alternative method to endovascular recanalization, when the cervical dissection is extensive and when huge secondary emboli are present along the MCA.

Extraintracranial Bypass as a Rescue Therapy for Symptomatic Flow Diverter Thrombosis

A 56-year-old female with a giant partially thrombosed unruptured carotid-ophthalmic aneurysm was treated with a Pipeline flow diverter. Three months after the procedure, in concomitance with the discontinuation of one of the antiplatelet medications, the patient suffered from a minor stroke and relapsing transient ischemic attacks. The angiography demonstrated the occlusion of the internal carotid artery, and a perfusion-weighted CT scan showed a condition of hypoperfusion. The patient underwent a double-barrel extraintracranial bypass. The postoperative course was uneventful and she has experienced no further ischemic events to date.

STA-MCA Bypass as a "Bridge" to Pituitary Surgery in a Patient with an Adenoma Occluding the Internal Carotid Artery: Case Report and Review of the Literature

Occlusion of the intracranial internal carotid artery (ICA) by a pituitary adenoma with resulting cerebral ischemia is a very rare but devastating occurrence. The authors present a case in which a condition of symptomatic ICA occlusion due to a giant pituitary adenoma was successfully treated using a preliminary extraintracranial bypass as a “bridge” to the tumor removal. A 52-year-old patient presented with a minor stroke followed by pressure-dependent transient ischemic attacks consistent with a condition of hypoperfusion. MR imaging and a digital subtraction angiography revealed a pituitary adenoma occluding the ICA on the right side. He underwent a superficial temporal artery to middle cerebral artery (STA-MCA) bypass with the aim of revascularizing the ischemic hemisphere and reducing the risk of perioperative stroke or stroke evolution. The patient was subsequently operated on to remove the adenoma through a transsphenoidal approach. The postoperative course was uneventful and the patient has suffered no further ischemic events. When there are no emergency indications to decompress the optical pathways but the patient is at risk of impending stroke because of ICA occlusion, a two-step strategy consisting of a bypass and subsequent removal of the pituitary adenoma may be a valuable option.

Urgent cerebral revascularization bypass surgery for iatrogenic skull base internal carotid artery injury

BACKGROUND

When feasible, the management of iatrogenic internal carotid artery (ICA) injury during skull base surgery is mainly endovascular.

OBJECTIVE

To propose a cerebral revascularization procedure as a rescue option when endovascular treatment is not feasible.

METHODS

We retrospectively reviewed all extracranial-intracranial (EC-IC) bypass procedures performed between July 2007 and January 2014.

RESULTS

From 235 procedures, we identified 8 consecutive patients with iatrogenic ICA injury managed with an EC-IC bypass. Injury to the ICA occurred during an endoscopic transsphenoidal surgery (n=3), endoscopic transfacial-transmaxillary surgery (n=1), myringotomy (n=1), cavernous sinus meningioma resection (n=1), posterior communicating artery aneurysm clipping (n=1), and cavernous ICA aneurysm coiling (n=1). Endovascular management was considered first-line treatment but was not successful. All patients received a high-flow EC-IC bypass. At a mean clinical/radiographic follow-up of 19 months (range, 3-36 months), all patients had a modified Rankin Scale score of 0 or 1. All bypasses remained patent.

CONCLUSION

Iatrogenic injury of the skull base ICA is uncommon but can lead to lethal consequences. Many injuries can be treated with endovascular techniques. However, certain cases may still require a cerebral revascularization procedure.

Intraoperative visualization of bilateral thrombosis in the posterior inferior cerebellar artery apparent in the telovelomedullary segment

Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures.

Changes in computed tomography perfusion parameters after superficial temporal artery to middle cerebral artery bypass: an analysis of 29 cases

Introduction Analysis of computed tomography perfusion (CTP) studies before and after superficial temporal artery to middle cerebral artery (STA-MCA) bypass is warranted to better understand cerebral steno-occlusive pathology. Methods Retrospective review was performed of STA-MCA bypass patients with steno-occlusive disease with CTP before and after surgery. CTP parameters were evaluated for change after STA-MCA bypass. Results A total of 29 hemispheres were bypassed in 23 patients. After STA-MCA bypass, mean transit time (MTT) and time to peak (TTP) improved. When analyzed as a ratio to the contralateral hemisphere, MTT, TTP, and cerebral blood flow (CBF) improved. There was no effect of gender, double vessel versus single vessel bypass, or time until postoperative CTP study to changes in CTP parameters after bypass. Conclusions Blood flow augmentation after STA-MCA bypass may best be assessed by CTP using baseline MTT or TTP and ratios of MTT, TTP, or CBF to the contralateral hemisphere. The failure of cerebrovascular reserve to improve after cerebral bypass may indicate irreversible loss of autoregulation with chronic cerebral vasodilation or the inability of CTP to detect these improvements.

Sphenoid ridge meningioma presenting as acute cerebral infarction

A previously healthy 52-year-old man presented to the emergency room with acute onset left hemiparesis and dysarthria. Brain computed tomography and magnetic resonance examinations revealed acute cerebral infarction in the right middle cerebral artery territory and a sphenoid ridge meningioma encasing the right carotid artery terminus. Cerebral angiography demonstrated complete occlusion of the right proximal M1 portion. A computed tomography perfusion study showed a wide area of perfusion-diffusion mismatch. Over the ensuing 48 hours, left sided weakness deteriorated despite medical treatment. Emergency extracranial-intracranial bypass was performed using a double-barrel technique, leaving the tumor as it was, and subsequently his neurological function was improved dramatically. We present a rare case of sphenoid ridge meningioma causing acute cerebral infarction as a result of middle cerebral artery compression.

Emergency superficial temporal artery to middle cerebral artery bypass after intravenous recombinant tissue plasminogen activator administration for acute cerebral ischemia in a patient with moyamoya disease

There are few study data to help in the decision whether to perform aggressive surgical revascularization, such as emergency bypass, after intravenous recombinant tissue plasminogen activator (rt-PA) administration in patients with progressive symptoms due to acute cerebral ischemia. A 33-year-old healthy male with no known previous medical history developed right hemiparesis and motor aphasia. No acute lesion was observed on admission computed tomography. According to the treatment protocol, emergency intravenous rt-PA administration was indicated within 3 h. After rt-PA administration, symptoms progressed to complete right hemiplegia. Emergency magnetic resonance imaging (MRI) showed an acute ischemic lesion in the left basal ganglia. MR angiography showed severe stenosis of the bilateral terminal portion of the internal carotid artery and occlusion of the left middle cerebral artery (MCA). Obvious diffusion-perfusion mismatch was detected. We performed digital subtraction angiography and diagnosed this condition as acute cerebral ischemia induced by moyamoya disease. We decided to perform emergency superficial temporal artery (STA)-MCA bypass to prevent further damage. The operation began 7 h after the administration of rt-PA and successful bypass was achieved. Symptoms stabilized and improved postoperatively. The majority of the area with preoperative hypoperfusion was rescued. Four months after surgery, the patient resumed his previous employment and continues to do well after 1.5 years of follow-up. This is the first report of emergency STA-MCA bypass performed after intravenous rt-PA administration for acute cerebral ischemia in a patient with moyamoya disease. We conclude that emergency STA-MCA bypass is a viable option for patients with moyamoya disease even after administration of rt-PA.

Imaging after direct and indirect extracranial-intracranial bypass surgery

OBJECTIVE

The purpose of this article is to describe the imaging features of different types of surgical cerebral revascularization techniques.

CONCLUSION

Surgical cerebral revascularization involves direct and indirect techniques. Direct revascularization entails anastomosing a branch of the external carotid artery to a cerebral artery. Indirect revascularization involves delivering an extracranial vascular supply in proximity to the surface of the brain. The results of these techniques have distinctive imaging features.

Extracranial-Intracranial Bypass for Stroke—Is This the End of the Line or a Bump in the Road?

The results of the recently published Carotid Occlusion Surgery Study, which failed to show a benefit of extracranial-intracranial (EC-IC) bypass over medical therapy in patients with symptomatic hemodynamically significant carotid occlusion, have been interpreted by some as the end of the line for EC-IC bypass in the management of stroke. Despite being carefully conceived and executed, several aspects of the trial design, study population, and underlying assumptions deserve further examination to determine how best to translate these results into clinical practice. Although a general expansion of EC-IC bypass use in this population would not be supported by the trial results, a select subset of patients with medically refractory hemodynamic symptoms may well benefit from surgery performed with sufficiently low perioperative morbidity. The potential for beneficial functional or cognitive impact of revascularization also remains under investigation. Limited application and further study with an eye to future developments, rather than complete abandonment, is warranted.

Urgent superficial temporal artery to middle cerebral artery bypass shortly after intravenous rt-PA

Whether to provide surgical intervention within 24 hours of intravenous recombinant tissue plasminogen activator (rt-PA) treatment is a subject of controversy. In this study, we report a case in which neurological deterioration was prevented by urgent bypass surgery performed shortly after rt-PA treatment.