Symptomatic carotid artery occlusion. A reappraisal of hemodynamic factors

Significance of atherosclerotic plaque location in recanalizing non-acute long-segment occlusion of the internal carotid artery

To investigate the significance of atherosclerotic plaque location in hybrid surgery comprising both endovascular recanalization approaches and carotid endarterectomy for symptomatic atherosclerotic non-acute long-segment occlusion of the internal carotid artery (ICA), 162 patients were enrolled, including 120 (74.1%) patients in the proximal plaque group and 42 (25.9%) in the distal plaque group. Surgical recanalization was performed in all patients, with successful recanalization in 119 (99.2%) patients in the proximal and 39 (92.9%) in the distal plaque group. The total successful recanalization rate was 97.5% (158/162) with a failure rate of 2.5% (4/162). Periprocedural complications occurred in 5 (4.2% or 5/120) patients in the proximal plaque group, including neck infection in two (1.7%), recurrent nerve injury in 1 (0.8%), and laryngeal edema in 2 (1.7%), and 2 (4.8%) in the distal plaque group, including femoral puncture infection in 2 (4.8%). No severe complications occurred in either group. Univariate analysis showed plaque location was a significant (P = 0.018) risk factor for successful recanalization, and multivariate analysis indicated that the plaque location remained a significant independent risk factor for recanalization success (P = 0.017). In follow-up 6-48 months after the recanalization surgery, reocclusion occurred in two (2.8%) patients in the proximal plaque group and 4 (13.3%) in the distal plaque group. In conclusion, although hybrid surgery achieves similar outcomes in patients with ICA occlusion caused by either proximal or distal atherosclerotic plaques, plaque location may be a significant risk factor for successful recanalization of symptomatic non-acute long-segment ICA occlusion.

A comparative study of multi and single post labeling delay pseudocontinuous arterial spin labeling in patients with carotid artery stenosis

PURPOSE

Arterial Spin Labeling (ASL) allows for the non-invasive visualization of brain perfusion to detect abnormalities. In unilateral carotid artery stenosis, one hemisphere is less supplied with blood which results in a lower cerebral blood flow (CBF) compared to the healthy side. ASL can be performed time-resolved using multiple post labeling delay (PLD) times after labeling or static with a single delay, the latter allowing for a faster and more robust acquisition while bearing the risk of a falsely set delay resulting in unusable images. The purpose of this study is to compare the performance of multi-PLD and single-PLD ASL in patients with unilateral carotid artery stenosis both as means of diagnosis and therapeutic follow-up examination.

METHODS

ASL perfusion data of 17 patients with known unilateral carotid artery stenosis was used to compare the diagnostic performance of the multi-PLD and single-PLD approach. Comparisons were made based on the CBF values and the added benefit of arrival time maps showing slower blood flow in multi-PLD ASL which might be overlooked in the individual delay images both before and after therapy.

RESULTS

Both the multi-PLD and the single-PLD data could identify the side of the stenosis with hemispheric differences in each approach (p < 0.001) and depict the normalization of CBF after therapy (p > 0.05). There were no differences between the individual methods (p > 0.05).

CONCLUSION

In this work, we could show that multi-PLD ASL in patients with unilateral carotid artery stenosis is beneficial as it provides both CBF and arrival time maps, however when only a single-PLD acquisition is available, this appears sufficient in a clinical setting to investigate the presence of a unilateral stenosis.

Incidence, severity and impact on functional outcome of persistent hypoperfusion despite large-vessel recanalization, a potential marker of impaired microvascular reperfusion: Systematic review of the clinical literature

The reported incidence of persistent hypoperfusion despite complete recanalization as surrogate for impaired microvascular reperfusion (IMR) has varied widely among clinical studies, possibly due to differences in i) definition of complete recanalization, with only recent Thrombolysis in Cerebral Infarction (TICI) grading schemes allowing distinction between complete (TICI3) and partial recanalization with distal occlusions (TICI2c); ii) operational definition of IMR; and iii) consideration of potential alternative causes for hypoperfusion, notably carotid stenosis, re-occlusion and post-thrombectomy hemorrhage. We performed a systematic review to identify clinical studies that carried out brain perfusion imaging within 72 hrs post-thrombectomy for anterior circulation stroke and reported hypoperfusion rates separately for TICI3 and TICI2c grades. Authors were contacted if this data was missing. We identified eight eligible articles, altogether reporting 636 patients. The incidence of IMR after complete recanalization (i.e., TICI3) tended to decrease with the number of considered alternative causes of hypoperfusion: range 12.5-42.9%, 0-31.6% and 0-9.1% in articles that considered none, two or all three causes, respectively. No study reported the impact of IMR on functional outcome separately for TICI-3 patients. Based on this systematic review, IMR in true complete recanalization appears relatively rare, and reported incidence highly depends on definition used and consideration of confounding factors.

A single-center retrospective study of the COCO technique in the treatment of chronic internal carotid artery occlusion

OBJECTIVE

To introduce a novel endovascular recanalization method and to investigate its success rate, periprocedural complications, and early outcomes in patients with chronic internal carotid artery occlusion (CICAO). As this novel technique was designed to treat CICAO with a full coaxial system, we named it the COCO technique.

METHODS

Data from consecutive patients with symptomatic CICAO who underwent endovascular recanalization in our institution were retrospectively reviewed. The COCO technique allows extracranial angioplasty and stenting with occasional intracranial angioplasty and stenting as needed to be performed in a coaxial fashion. Patients' demographic and clinical information, morphologic characteristics, procedural results, complications, and follow-up outcomes were recorded.

RESULTS

Forty-nine patients were enrolled in this study. The technical success rate was 89.8% (44/49). Four patients experienced intraoperative complications, two patients had a slight subarachnoid hemorrhage, and two patients had asymptomatic dissection. Distal embolization or carotid-cavernous arteriovenous fistula was not detected. In addition, three patients developed hemorrhagic complications and three developed postoperative ischemic complications. All these patients improved after conservative treatment and subsequent rehabilitation. During the median 6 (3-6) months of follow-up, one patient died of severe pneumonia and two patients experienced recurrent ischemic events. In patients with successful recanalization, modified Rankin Scale scores were lower at the 3-month follow-up than at baseline (1 (0-2) vs 2 (1-2), P=0.04). Restenosis was observed in six (15.8%) patients.

CONCLUSIONS

Our study showed that the COCO technique is effective and safe for endovascular recanalization in patients with CICAO and has low periprocedural complications and favorable functional outcomes.

Extracranial-Intracranial Cerebral Revascularization for Atherosclerotic Vessel Occlusion: An Updated Systematic Review of the Literature

BACKGROUND

Atherosclerotic steno-occlusive cerebrovascular disease includes extracranial carotid occlusive and intracranial atherosclerotic disease. Despite the negative findings in Carotid Occlusion Surgery Study (COSS), many large centers continue to report favorable results for revascularization surgery in select groups of patients. The aim of our study was to perform an updated systematic review to investigate the role of revascularization surgery for atherosclerotic steno-occlusive patients in the modern era.

METHODS

Five independent reviewers performed Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided literature searches in October 2022 to identify articles reporting clinical outcomes in adult patients undergoing bypass for atherosclerotic steno-occlusive disease. Primary endpoints used were perioperative and long-term ischemic strokes, intracerebral hemorrhage, bypass patency, and favorable clinical outcomes. Study quality was evaluated with Newcastle-Ottawa, JADAD, and the Oxford Center for Evidence-Based Medicine scales.

RESULTS

A total of 6709 articles were identified in the initial search. Of these articles, 50 met the inclusion criteria and were included in the systematic review. A notable increase in the proportion of articles published over the past 10 years was observed. There were 6046 total patients with 4447 bypasses performed over the period from 1978 to 2022. The average length of follow-up was 2.75 ± 2.71 years. The average Newcastle-Ottawa was 6.23 out of 9 stars. There was a significant difference in perioperative stroke (odds ratio [OR], 0.65 [0.48-0.87]; P = 0.004), long-term ischemia (OR, 0.32 [0.23-0.44]; P < 0.0001), overall ischemia (OR, 0.36 [0.28-0.44]; P < 0.0001), and favorable outcomes (OR, 3.63 [2.84-4.64]; P < 0.0001) when comparing pre-COSS to post-COSS time frames in favor of post-COSS.

CONCLUSIONS

Based on a systematic review of 50 articles, the existing literature indicates that long-term stroke rates and favorable outcomes for surgical revascularization for steno-occlusive disease have improved over time and are lower than previously reported. Improved patient selection, perioperative care, and surgical techniques may contribute to improved outcomes.

Non-association of stroke risk with intracranial hemodynamic steal in patients with symptomatic internal carotid artery occlusions

OBJECTIVES

Paradoxical intracranial hemodynamic steal (IHS) is known in patients having persistent proximal arterial occlusions and is linked with early neurological worsening. However, stroke risk specific to symptomatic internal carotid artery occlusions (SICAO) having paradoxical IHS is unknown. Therefore, we aimed to investigate the association of paradoxical IHS in SICAO patients with stroke recurrence during a one-year follow-up.

MATERIALS AND METHODS

We prospectively enrolled adult patients having SICAO with a recent history of ischemic events. Steal magnitude (SM) to classify patients in IHS and non-IHS categories was evaluated by a breath-holding test using bilateral transcranial doppler (TCD). Patients were prescribed optimal medical therapy and followed up for one year for any ischemic stroke/TIA/cardiovascular death.

RESULTS

36 SICAO patients, mean age of 56 years, were assessed using TCD at median 22.5 days (Interquartile range, IQR= 9-42), and 11 (30.6%) had paradoxical IHS with median SM 12% (IQR= 6%-18%). On follow-up, 7 (19.4%) patients had event recurrence and its association with IHS was non-significant (IHS vs non-IHS, 18.2% vs 20%; Log-rank statistics=0.006; P=0.940). On Cox regression analysis, event recurrence was independently associated with the presence of significant contralateral stenosis only (regression coefficient= 2.237; P= 0.012; 95% CI= 1.63-53.89).

CONCLUSIONS

IHS prevalence among SICAO is high. However, paradoxical IHS was not associated with an increased risk of stroke in SICAO. Therefore, the presence of paradoxical IHS in SICAO may be considered a transit state and does not necessarily imply an increased risk of stroke.

Anterior cerebral artery dilation to increase cerebral perfusion in a patient with chronic internal carotid artery occlusion

Chronic internal carotid artery occlusions (CICAO) increase the risk of stroke recurrence and cognitive dysfunction. Here, we describe the case of an adult patient with ipsilateral CICAO who underwent endovascular treatment of anterior cerebral artery stenosis to improve cerebral perfusion. First, the patient presented ataxia and left facial palsy. Magnetic resonance imaging (MRI) showed right hemispherpe cerebral infarct, right CICAO, and sub-occlusive stenosis of the left bulbar internal carotid artery. Stenting of the left carotid artery was performed. One year later, she experienced acute walking imbalance and left hemiparesis. MRI showed new watershed and anterior cerebral artery infarctions, worsening of the right hemisphere hypoperfusion, and a new severe stenosis of the right anterior cerebral artery. Dilation of this stenosis was performed. Perfusion parameters, clinical deficit, and cognitive functions improved after the endovascular treatment, and the patient had no stroke recurrence.

The additional value of high-resolution vessel wall imaging in screening suitable chronic internal carotid artery occlusion candidates for endovascular recanalization: comparison with digital subtraction angiography

BACKGROUND

High-resolution vessel wall imaging (HR-VWI) can provide information about exact occluded length, etiology, and the presence of intraluminal thrombus or residual cavity.

PURPOSE

To investigate the extra value of HR-VWI in screening patients with chronic internal carotid artery occlusion (CICAO) for recanalization suitability in comparison with digital subtraction angiography (DSA).

MATERIAL AND METHODS

We retrospectively reviewed patients who underwent endovascular recanalization with no internal carotid artery signal on magnetic resonance angiography (MRA) and whose both preoperative DSA and HR-VWI data were available. Patients were classified into type I (focal occlusion distal to ophthalmic artery), type II or III (occlusion proximal or at/distal to clinoid segment), and near-occlusion. Occlusion etiology and suitability for recanalization were analyzed both on preoperative DSA and HR-VWI. Accuracy of occlusion classification and differences in the modified Rankin scale scores between the baseline and follow-up were estimated.

RESULTS

A total of 20 patients were included. With intraoperative DSA as the gold standard, we found HR-VWI could additionally show intraluminal thrombi. Preoperative DSA misclassified one near-occlusion, one type I occlusion, and one type II occlusion as type III occlusions, and one near-occlusion as a type II occlusion. Therefore, compared with the preoperative DSA, three additional cases were successfully recanalized based on HR-VWI. The accuracy of HR-VWI was higher than preoperative DSA (100% vs. 80%). Prognosis improvement of type I was significantly better than type II and near-occlusion (P<0.05).

CONCLUSION

HR-VWI can identify occluded etiology, extent, and classification of CICAO. This information is potentially useful in screening candidates for endovascular recanalization and helpful to indicate prognosis.

Arterial transit artifacts observed on arterial spin labeling perfusion imaging of carotid artery stenosis patients: What are counterparts on symptomatology, dynamic susceptibility contrast perfusion, and digital subtraction angiography?

PURPOSE

To investigate possible relationships between the presence and location of arterial transit artifacts (ATA) and clinical symptoms, digital subtraction angiography (DSA), and dynamic susceptibility contrast (DSC) perfusion imaging abnormalities in patients with carotid artery stenosis (CAS).

METHODS

Forty-seven patients who underwent arterial spin labeling (ASL) and DSC perfusion imaging in the same period diagnosed with > 50% unilateral internal carotid artery (ICA) stenosis by DSA performed 24 h after perfusion imaging were included. The presence of ATA, localization and hypoperfusion were evaluated using ASL interpretation. Maps derived from DSC perfusion, symptomatology, stenosis rates, and collateralization findings observed in DSA were investigated. Probable relationships were evaluated.

RESULTS

ATA on ASL were detected in 68.1% (32/47); 40.6% (13/32) of ATAs were observed in the distal middle cerebral artery (MCA) trace, 50% (16/32) in the intracranial ICA and MCA traces, and 9.4% (3/32) in the intracranial ICA trace. When classifications based on the ATA presence and localization was made, qualitative and quantitative CBF, MTT, and TTP abnormalities, symptomatology, stenosis rates, and collateralization findings significantly differed between groups (p < 0.05).

CONCLUSION

The presence and localization of ATA in patients with CAS may provide essential insights into cerebral hemodynamics and the CAS severity. ATAs observed only in the distal MCA trace may represent early-stage perfusion abnormalities and a moderate level of stenosis. ATA in the ICA trace may related to a more advanced level of perfusion abnormalities, critical stenosis rates, symptom or collateralization presence.

Rapid Recovery from Subacute to Chronic Ischemic Stroke Following Revascularization by Carotid Stenting: Preliminary Findings

Background

Rapid neurological recovery from subacute to chronic ischemic stroke in subset of patients following carotid revascularization was observed.

Objective

Retrospective analysis of data of the patients who had shown rapid recovery from subacute to chronic ischemic stroke following revascularization by Carotid stenting.

Materials and Methods

We retrospectively analyzed pooled data from our carotid stenting patients done during January 2009 to January 2020.The inclusion criterion of the study was patients with rapid recovery within 24 h following revascularization by carotid stenting. There were total of 12 such patients. There were 8 males and 4 females. Apart from NIHSS, stroke severity was measured on MRI by ASPECTS score and cognitive function by MMSE. Each of these patients has undergone Carotid Stenting with distal protection for high-grade stenosis.

Results

All of these 12 patients had Prestenting ASPECTS score ranging 8-10. Prestenting NIHSS score was ranging from 6-12 with an average of 8. Postprocedure NIHSS score was decreased to a range of 0-4 with average of 3.Prestenting MMSE was ranging 14-20 with an average of 18 score which turned into Post-stenting MMSE scale ranging 24-28 with an average of 26.Each of these patients shows decrease in NIHSS score by at least 50% in 24h to be called rapid recovery or Lazarus phenomenon. Additionally, they show significant improvement in cognitive function on MMSE scale.

Conclusion

Rapid recovery from subacute to chronic ischemic stroke following revascularization by Carotid Stenting is potentially feasible in subset of patient who has mild to moderate deficit but high ASPECTS score.

Biting Innovations of Mosquito-Based Biomaterials and Medical Devices

Mosquitoes are commonly viewed as pests and deadly predators by humans. Despite this perception, investigations of their survival-based behaviors, select anatomical features, and biological composition have led to the creation of several beneficial technologies for medical applications. In this review, we briefly explore these mosquito-based innovations by discussing how unique characteristics and behaviors of mosquitoes drive the development of select biomaterials and medical devices. Mosquito-inspired microneedles have been fabricated from a variety of materials, including biocompatible metals and polymers, to mimic of the mouthparts that some mosquitoes use to bite a host with minimal injury during blood collection. The salivary components that these mosquitoes use to reduce the clotting of blood extracted during the biting process provide a rich source of anticoagulants that could potentially be integrated into blood-contacting biomaterials or administered in therapeutics to reduce the risk of thrombosis. Mosquito movement, vision, and olfaction are other behaviors that also have the potential for inspiring the development of medically relevant technologies. For instance, viscoelastic proteins that facilitate mosquito movement are being investigated for use in tissue engineering and drug delivery applications. Even the non-wetting nanostructure of a mosquito eye has inspired the creation of a robust superhydrophobic surface coating that shows promise for biomaterial and drug delivery applications. Additionally, biosensors incorporating mosquito olfactory receptors have been built to detect disease-specific volatile organic compounds. Advanced technologies derived from mosquitoes, and insects in general, form a research area that is ripe for exploration and can uncover potential in further dissecting mosquito features for the continued development of novel medical innovations.

Chronic remote ischemic conditioning for symptomatic internal carotid or middle cerebral artery occlusion: A prospective cohort study

AIMS

Remote ischemic conditioning (RIC) has been demonstrated to reduce recurrent stroke in patients with intracranial artery stenosis. This study aimed to evaluate the effects of RIC in patients with the symptomatic internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion.

METHODS

This study is based on a high-volume single-center prospective cohort study in China, which included patients with symptomatic ICA or MCA occlusion with impaired hemodynamics and receiving chronic RIC. Clinical follow-up visits were performed regularly, and cardio-cerebrovascular events were assessed.

RESULTS

In total, 131 patients (68 with ICA occlusion and 63 with MCA occlusion; mean age, 52.6 ± 13.7 years; stroke, 73.5%; transient ischemic attack TIA, 26.5%) qualified for the analysis; the mean follow-up period was 8.8 years (range, 3-14 years). The compliance of RIC was 95.6 ± 3.7%, and no associated severe adverse events happened. The annual risk of ischemic stroke and ischemic cerebrovascular events was 2.4% and 3.3%, respectively. The cumulative probabilities of ischemic cerebrovascular events and major adverse cardiovascular and cerebrovascular events were 32.8% and 44.8% at 14 years, respectively.

CONCLUSION

In patients with symptomatic ICA or MCA occlusion with impaired hemodynamics, chronic RIC is well-tolerated, and it appears to be associated with a low annual risk of ischemic stroke and cardio-cerebrovascular events.

Evolution of the Flow Patterns After Endovascular Treatment in Patients with High-Grade Carotid Artery Stenosis - the Clinical Value of Insonation of the Supratrochlear Artery and Alternating Flow

AIM

We aimed to describe the evolution of flow pattern in the ophthalmic artery (OA) and supratrochlear artery (SA) by transcranial Doppler (TCD) ipsilateral to a severe proximal carotid artery stenosis before and after staged endovascular treatment (EVT).

METHODS

We insonated and recorded the flow patterns of OA and SA in 63 patients with ≥ 80% carotid artery stenosis before and after staged carotid angioplasty and stenting at 2-4 weeks apart. Based on the direction of OA and SA blood flow, we categorized patients into (1) reversed, (2) alternating, or (3) forward flow, groups. We evaluated the evolving sonographic flow patterns in OA and SA at the 3-time points and correlated them with the stenotic and flow velocity change.

RESULTS

Despite the disconcordance between OA and SA, the evolution of flow direction were evoluted from reversed to alternating or from alternating to forward in both OA and SA. OA and SA's disagreement rate at three-time points was 19.1%, 49.2%, and 28.6%, respectively. After angioplasty alone, we detected an alternating flow in 21 (33.3%) and 46 (73.0%) patients in OA and SA, respectively. Alternating flow patterns in SA persisted in 20 patients (31.7%) after stenting. The post-angioplasty residual stenosis did not differ between the three flow pattern groups (p>0.05).

CONCLUSIONS

An alternating flow in OA or SA might mark the hemodynamic recovery after EVT. Insonation of SA may provide supporting evidence for hemodynamic change in patients with carotid artery stenosis undergoing EVT.

The Sutureless Excimer Laser Anastomosis Clip Pilot Study: a feasibility and safety study

Background

The excimer laser-assisted non-occlusive anastomosis (ELANA) bypass technique may have the advantage of its non-occlusive design in the treatment of last-resort cases where endovascular treatment or direct clipping is considered to be unsafe. However, the technique remains technically challenging. Therefore, a sutureless ELANA Clip device (SEcl) was developed to simplify the technique avoiding tedious anastomosis stitching in depth.

The present study investigates the clinical feasibility and safety of the SEcl technique.

Methods

Three patients with complex and large aneurysms in the anterior circulation were selected after multidisciplinary consensus that the aneurysms were too complex for endovascular or direct clipping treatment options. Bypass surgery was considered as a last-resort treatment option, and after preoperative evaluation and informed consent, SEcl bypass surgery was performed. Applicability, technical aspects and patient outcomes are assessed.

Results

All aneurysms were excluded from the circulation. The creation of the intracranial anastomosis was easier and faster. No device-related serious adverse events were encountered, and all outcomes were favorable (one patient stable Modified Rankin Scale, two patients improved).

Conclusion

The SEcl anastomosis technique is feasible and, considering the severity of the disease, relatively safe. It can be considered a treatment option in very difficult-to treat last-resort aneurysm cases. From this study, further developments in minimizing clip size and application in cardiac surgery are initiated.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05182-1.

Different Grades of Collateral Circulation for Evaluating Cerebral Hemodynamic Status in Carotid Artery Stenosis

Normally, ipsilateral hemodynamic compromise of patients with carotid stenosis (CS) is subjectively identified by collateral circulation through cerebral angiography in the clinical process. It is unclear whether collaterals would linearly determine cerebral perfusion in CS patients. This study aimed to investigate the independent role of collateral circulation on cerebral perfusion in CS patients and the underlying interrelations among them. From 2017 to 2020, 124 CS patients who underwent carotid endarterectomy (CEA) with both preoperative CTP and digital substruction angiography (DSA) images were enrolled. Division of subgroups was based on degree of CS (50-70%, 70-90%, and near-occlusion (NO)) and grades of collateral circulation by DSA. Differences in CTP parameters between CS patients with different collateral circulation were analyzed. Among 124 CS patients, grades 2 and 3 were highly associated with carotid NO (n = 22, 32.35% and n = 22, 32.35%) compared with others (P < 0.0001). The collateral circulation was found to have poor relation with cerebral perfusion parameters in all enrolled patients but significantly improved ipsilateral cerebral perfusion in patients with carotid NO (P < 0.05). Linear hemodynamic compromise was barely related to degree of CS in lobes supplied by middle cerebral artery (MCA) except the frontal lobe (P < 0.05). The grades of collateral circulation are positively associated with degree of CS while having nonsignificant effect on cerebral perfusion. Overall, severity of CS is poorly related to hemodynamic status while the perfectibility of compensation defined by grades of collateral circulation effectively alleviates ipsilateral cerebral perfusion deficit in carotid NO.

Perforating artery flow velocity and pulsatility in patients with carotid occlusive disease. A 7 tesla MRI study

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Patients with COD show lower perforating artery flow velocity in watershed areas.

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Reduced perforating artery flow seems to be related to subcortical ischemic burden.

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Perforating artery function may be relevant for clinical outcome in COD patients.

Patients with carotid occlusive disease express altered hemodynamics in the post-occlusive vasculature and lesions commonly attributed to cerebral small vessel disease (SVD). We addressed the question if cerebral perforating artery flow measures, using a novel 7T MRI technique, are altered and related to SVD lesion burden in patients with carotid occlusive disease.

21 patients were included with a uni- (18) or bilateral (3) carotid occlusion (64±7 years) and 19 controls (65±10 years). Mean flow velocity and pulsatility in the perforating arteries in the semi-oval center (CSO) and basal ganglia (BG), measured with a 2D phase contrast 7T MRI sequence, were compared between patients and controls, and between hemispheres in patients with unilateral carotid occlusive disease. In patients, relations were assessed between perforating artery flow measures and SVD burden score and white matter hyperintensity (WMH) volume.

CSO perforating artery flow velocity was lower in patients than controls, albeit non-significant (mean difference [95% confidence interval] 0.08 cm/s [0.00–0.16]; p = 0.053), but pulsatility was similar (0.07  [-0.04–0.18]; p = 0.23). BG flow velocity and pulsatility did not differ between patients and controls (velocity = 0.28 cm/s [-0.32–0.88]; p = 0.34; pulsatility = 0.00 [-0.10–0.11]; p = 0.97). Patients with unilateral carotid occlusive disease showed no significant interhemispheric flow differences. Though non-significant, within patients lower CSO (p = 0.06) and BG (p = 0.11) flow velocity related to larger WMH volume.

Our findings suggest that carotid occlusive disease may be associated with abnormal cerebral perforating artery flow and that this relates to SVD lesion burden in these patients, although our observations need corroboration in larger study populations.

Correlations between cognitive function and gray matter alterations in patients with acute lacunar stroke

Researchers emphasized acute lacunar stroke (ALS) patients suffer from poor social/physical outcomes, cognitive decline, and decreased quality of life. We hypothesized brain abnormalities may occur in ALS during this particular stage and may be associated with cognitive deficits upon evaluation. We investigated structural abnormalities in ALS using magnetic resonance imaging and voxel-based morphometry conducted on 28 healthy controls (HC) and 29 patients with ALS and proximal anterior circulation occlusion within 12 hours of symptom onset. Mini-Mental State Examination (MMSE) scores were used to evaluate cognitive dysfunction. Decreased gray matter (GM) in ALS vs. HC was predominantly in the superior frontal gyrus, inferior frontal gyrus, insula, superior temporal gyrus (STG), heschl gyrus, middle temporal gyrus (MTG), posterior cingulate cortex (PCC), hippocampus (HIP), and others. Positive correlation was found between GM density and MMSE scores in STG ( r = 0.59, p = 0.0007), MTG ( r = 0.46, p = 0.01), PCC ( r = 0.42, p = 0.02), HIP ( r = 0.4, p = 0.03), and medial prefrontal cortex ( r = 0.5, p = 0.005). This study provided further information on pathophysiological/morphological mechanisms related to cognitive impairment in ALS and is the basis for further studies in aging-related diseases.

Magnetic resonance markers of bilateral neuronal metabolic dysfunction in patients with unilateral internal carotid artery occlusion

OBJECTIVES

To evaluate cerebral hemodynamic, metabolic and anatomic changes occurring in patients with unilateral occlusion of the internal carotid artery (ICA).

MATERIALS AND METHODS

Twenty-two patients with unilateral occlusion of ICA and twenty age and sex matched healthy subjects were included in the study. Single voxel proton magnetic resonance spectroscopy (¹H-MRS) of the centrum semiovale, semi-automated hippocampal volumetry in T1-weighted scans and transcranial Doppler examination (TCD) with calculation of Breath Holding Index (BHI) were performed in both groups. Metabolic, anatomic, and hemodynamic features were compared between the two groups.

RESULTS

The N-acetylaspartate (NAA)/choline (Cho) ratio was significantly lower in both hemispheres of enrolled patients compared to controls (p = 0.005 for the side with occlusion, p = 0.04 for the side without occlusion). The hippocampus volume was significantly reduced bilaterally in patients compared to healthy subjects (p = 0.049). A statistically significant difference in BHI values was observed between the side with occlusion and without occlusion (p = 0.037) of the patients, as well as between BHI values of the side with occlusion and healthy volunteers (p = 0.014).

DISCUSSION

Patients with unilateral ICA occlusion have reduced NAA/Cho ratio in the white matter of both hemispheres and have bilateral atrophy of hippocampus. The alteration of hemodynamics alone cannot explain these changes.

Endovascular revascularization of symptomatic chronic total occlusions of the internal carotid artery using a proximal balloon protection device

To investigate the feasibility, efficacy, and safety of endovascular recanalization for symptomatic chronic internal carotid artery occlusions (ICAO). Thirty patients with symptomatic chronic ICAO were treated using the endovascular recanalization method. Proximal balloon protection devices were used to prevent embolic migration by completely blocking the blood flow. The morphology of the internal carotid artery (ICA) at the occluded segment based on catheter angiography was analyzed. Recanalization of symptomatic chronic internal carotid artery occlusion (CICAO) was successful in 20 of the 30 patients (66.7%). The time required for successful revascularization ranged from 120 to 180 min (mean, 150 min). Of the 20 successful patients, 14 were at the cervical ICAs, and six were at the intracranial ICAs. No permanent complications occurred in our study. Ischemic symptoms related to chronic ICAO did not occur during the 18.3 month follow-up period (range, 12-24 months) in the 20 successful patients. Endovascular revascularization can improve hemodynamic compromise. The treated sites of all 20 successfully recanalized patients were patent on computed tomographic angiography or carotid duplex sonography, and no case with >50% restenosis was observed during the follow-up period. Three patients with failed recanalization had a stroke during the follow-up period. Endovascular revascularization of symptomatic CICAO using a proximal balloon protection device is technically feasible in selected patients, and the outcomes are favorable for patients who benefit from revascularization.

Combined Endovascular and Surgical Treatment of Chronic Carotid Artery Occlusion: Hybrid Operation

Objectives

The optimal treatment choice of chronic carotid artery occlusion (CAO) remains inconclusive. This study was aimed at exploring the safety and effectiveness of hybrid surgery in the treatment of CAO and at determining predictors for successful recanalization.

Methods

In this study, we enrolled 37 patients with CAO who underwent hybrid surgical treatment during the period 2016–2018. We extracted and analyzed patients' demographic data, disease characteristics, surgical success rates, perioperative complications, and prognosis.

Results

A total of 37 patients with symptomatic CAO underwent hybrid surgical treatment. Thirty cases (81.1%) were successfully recanalized, while seven were not. Blood reflux after carotid endarterectomy occurred in 18 patients (60%) of the success group and 1 (14.3%) of the failure group (OR, 9.0; 95% CI, 0.95-54.5; P = 0.042). The rate of distal ICA reconstruction below the clinoid segment was 20 (66.7%) in the success group and 1 (14.3%) in the failure group (OR, 12.0; 95% CI, 1.3-113.7; P = 0.029). In patients with successful recanalization, no ischemic events occurred after surgery and during follow-up, but restenosis of >50% was found in one case. In the failure group, two patients experienced recurrent ischemic events during follow-up. Perfusion imaging in successful recanalization cases is significantly improved, preoperative I/C ratio was 1.44 (IQR 1.27-1.55), and postoperative 1.12 (IQR 1.05-1.23). National Institutes of Health Stroke Scale (NIHSS) score of successful recanalization cases was 5.35 (2.26) before surgery and 2.03 (1.40) at 6 months (P < 0.01).

Conclusion

Hybrid surgery might be a safe and effective way to treat CAO. Distal internal carotid artery reconstruction to below the clinoid segment and blood reflux after carotid endarterectomy are predictors of successful recanalization.

A Novel Endovascular Technique for Recanalization of Carotid Artery Chronic Total Occlusion: Staged Carotid Angioplasty and Stenting

AIM

Symptomatic carotid artery chronic total occlusion (SCACTO) can lead to neurocognitive function decline and carries a high risk or recurrent stroke. The treatment option is limited, endovascular intervention may be an alternative treatment but still controversial. To our knowledge, the staged carotid angioplasty and stenting (SCAS) did not previously reported. The purpose of this study was to report our experiences in this novel technique.

METHODS

In 2017-2018, we attempted the staged carotid angioplasty and stenting (SCAS) approach in 13 patients who received SCACTO treatment. The SCAS approach involves two stages of intervention. The first stage involves initial recanalization and initial small-sized balloon angioplasty. The second stage, which is performed 4-6 weeks later, involves angioplasty and carotid stent placement.

RESULTS

The success rate of SCAS was 76.9%. At the second stage, the lumen remained patent in all the patients. The mean spontaneous increase in lumen diameter after 4-6 weeks was 51.7%. The median length of the stent was 4.0 cm, and the median number of stents used was 1. One patient had a complication of dissection, with a complication rate of 7.6%.

CONCLUSIONS

SCAS is a novel technique in the endovascular treatment of SCACTO. It is a feasible and safe approach that could reduce the complication rate and number of carotid stents needed.

Symptomatic isolated internal carotid artery occlusion with initial medical management: a monocentric cohort

BACKGROUND

Symptomatic isolated carotid artery occlusions (ICAO) can lead to disability, recurrent stroke, and mortality, but natural history and best therapeutic management remain poorly known. The objective of this study was to describe our cohort of ICAO patients with an initial medical management.

METHODS

We conducted a retrospective study including consecutive patients admitted to our Comprehensive Stroke Center for ICAO within 24 h after stroke onset between January 2016 and September 2018. Patients with immediate endovascular therapy (EVT) were excluded. Medical treatment was based on anticoagulation (delayed by 24 h if intravenous thrombolysis was performed). 'Rescue' EVT was considered if first-week neurological deterioration (FWND) occurred.

RESULTS

Fifty-six patients were included, with a median National Institutes of Health Stroke Scale (NIHSS) of 3. Eleven patients (20%) had FWND during the first week, four benefited from rescue EVT. A mismatch volume > 40 cc on initial perfusion imaging and FLAIR vascular hyperintensities were associated with FWND (p = 0.007 and p = 0.009, respectively). Thirty-eight patients (69%) had a good outcome (modified Rankin Scale mRS 0-2) at 3 months, 36 (69%) had an excellent outcome (mRS 0-1). Seventeen patients (38%) had carotid patency on 3-month control imaging. Recurrences occurred in six (13%) of the survivors (mean follow-up: 13.6 months).

CONCLUSION

Our results suggest that the prognosis of patients with acute ICAO was favorable with a medical strategy, albeit a substantial rate of FWND and recurrence. FWND was well predicted by a core-perfusion mismatch volume > 40 cc. Randomized controlled trials are necessary to assess the benefit of EVT in ICAO.

Cortical and Internal Watershed Infarcts Might Be Key Signs for Predicting Neurological Deterioration in Patients with Internal Carotid Artery Occlusion with Mild Symptoms

Background

Treatment for acute ischemic stroke due to large vessel occlusion (LVO) with mild symptoms is under discussion. Although most patients have good outcomes, some patients deteriorate and have unfavorable results. Imaging findings that predict the prognosis of LVO with mild symptoms are needed to identify patients who require treatment. In this study, we focused on watershed infarctions (WSIs), because this clinical phenomenon quite sensitively reflects changes in cerebral blood flow. The purpose of this study was to assess positive rates of WSI on MRI findings in patients with internal carotid artery (ICA) occlusion, and compare WSI-positive rates between patients divided according to their clinical course.

Methods

We retrospectively collected data of 1,531 patients who presented with acute ischemic stroke between June 2006 and July 2019. Among them, we chose symptomatic ICA occlusion patients with a past history of atrial fibrillation who were treated conservatively. We divided these patients into two groups, those with maintenance or improvement in their NIHSS score after hospitalization, and those whose NIHSS score worsened. We compared WSI-positive rates between these two groups.

Results

Thirty-seven of the 1,531 patients were included in this study. Of them, total NIHSS score was maintained or improved in 8 patients (group A), 3 of whom (37.5%) had internal watershed infarctions (IWIs). In group B, consisting of patients whose NIHSS score worsened by >2 at 7 days from symptom onset, 24 (82.8%) had IWIs. Group A thus had statistically lower IWI positivity rates than group B (p = 0.02). Three patients (37.5%) in group A had cortical watershed infarctions (CWIs), while 27 patients in group B (93.1%) had CWIs. Group A thus had a significantly lower CWI positivity rate than group B (p = 0.002).

Conclusion

In patients with mildly symptomatic ICA occlusion, CWIs and IWIs might be key signs for predicting neurological deterioration after hospitalization.

Evaluation of chronic carotid artery occlusion by non-contrast 3D-MERGE MR vessel wall imaging: comparison with 3D-TOF-MRA, contrast-enhanced MRA, and DSA

OBJECTIVES

To analyze the accuracy of a non-contrast MR vessel wall imaging technique, three-dimensional motion-sensitized driven equilibrium prepared rapid gradient echo (3D-MERGE) for diagnosing chronic carotid artery occlusion (CCAO) characteristics compared with 3D time-of-flight (TOF) MRA, and contrast-enhanced MRA (CE-MRA), using digital subtraction angiography (DSA) as a reference standard.

METHODS

Subjects diagnosed with possible CCAO by ultrasound were retrospectively analyzed. Patients underwent 3.0-T MR imaging with 3D-MERGE, 3D-TOF-MRA, and CE-MRA followed by DSA within 1 week. Diagnostic accuracy of occlusion, occlusion site, and proximal stump condition were assessed independently on 3 MRI sequences and DSA. Agreement of the above indicators was evaluated in reference to DSA.

RESULTS

One hundred twenty-four patients with 129 suspected CCAO (5 with bilateral occlusions) met the inclusion criteria for our study. 3D-MERGE demonstrated a sensitivity, specificity, and accuracy of 97.0%, 86.7%, and 94.6%, respectively, with excellent agreement (Cohen's κ = 0.85; 95% CI, 0.71, 0.94) for diagnosing CCAO in reference to DSA. 3D-MERGE was superior in diagnosing CCAO compared with 3D-TOF-MRA (Cohen's κ = 0.61; 95% CI, 0.42, 0.77) and similar to CE-MRA (Cohen's κ = 0.93; 95% CI, 0.86, 1.00). 3D-MERGE also had excellent agreement compared with DSA for assessing occlusion sites (Cohen's κ = 0.85; 95% CI, 0.71, 0.97) and stump condition (Cohen's κ = 0.83; 95% CI, 0.71, 0.94). Moreover, 3D-MERGE provided additional information regarding the occluded segment, such as distal lumen collapse and vessel wall lesion components.

CONCLUSION

3D-MERGE can reliably assess chronic carotid occlusive characteristics and has the ability to identify other vessel wall features of the occluded segment. This non-contrast MR vessel wall imaging technique is promising for assessment of CCAO.

KEY POINTS

• Excellent agreement was found between 3D-MERGE and DSA for assessing chronic carotid artery occlusion, occlusion site, and proximal stump condition. • 3D-MERGE was shown to be a more accurate and efficient tool than 3D-TOF-MRA to detect the characteristics of the occluded segment. • 3D-MERGE provides not only luminal images for characterizing the proximal characteristics of occlusion but also vessel wall images for assessing the distal lumen and morphology of occlusion segment, which might help clinicians to optimize the treatment strategy for patients with chronic carotid artery occlusion.

Revascularization surgery for symptomatic non-moyamoya intracranial arterial stenosis or occlusion

OBJECTIVE

Previous trials rejected a role of extracranial-to-intracranial bypass surgery for managing symptomatic atheromatous disease. However, hemodynamic insufficiency may still be a rationale for surgery, provided the bypass can be performed with low morbidity and patency is robust.

METHODS

Consecutive patients undergoing bypass surgery for symptomatic non-moyamoya intracranial arterial stenosis or occlusion were retrospectively identified. The clinical course and surgical outcomes of the cohort were evaluated at 6 weeks, 6 months, and annually thereafter.

RESULTS

From 1992 to 2017, 112 patients underwent 127 bypasses. The angiographic abnormality was arterial occlusion in 80% and stenosis in 20%. Procedures were performed to prevent future stroke (76%) and stroke reversal (24%), with revascularization using an arterial pedicle graft in 80% and venous interposition graft (VIG) in 20%. A poor outcome (bypass occlusion, new stroke, new neurological deficit, or worsening neurological deficit) occurred in 8.9% of patients, with arterial pedicle grafts (odds ratio [OR] 0.15), bypass for prophylaxis against future stroke (OR 0.11), or anterior circulation bypass (OR 0.17) identified as protective factors. Over the first 8 years following surgery the 66 cases exhibiting all three of these characteristics had minimal risk of a poor outcome (95% confidence interval 0%-6.6%).

CONCLUSIONS

Prophylactic arterial pedicle bypass surgery for anterior circulation ischemia is associated with high graft patency and low stroke and surgical complication rates. Higher risks are associated with acute procedures, typically for posterior circulation pathology and requiring VIGs. A carefully selected subgroup of individuals with hemodynamic insufficiency and ischemic symptoms is likely to benefit from cerebral revascularization surgery.

Extracranial-intracranial bypass surgery for occlusive atherosclerotic disease of the anterior cerebral circulation: protocol for a systematic review and meta-analysis

BACKGROUND

Occlusive atherosclerotic disease of the anterior cerebral circulation is one of the most common causes of anterior circulation ischemia and stroke. Treatment options include medical therapies (including antiplatelet use, blood pressure control, lipid reduction, and lifestyle modification) and extracranial-intracranial bypass surgery (such as superficial temporal artery-middle cerebral artery bypass). However, the optimal treatment remains unclear. The objective of this study will be to compare the efficacy of and extracranial-intracranial bypass surgery with that of other medical therapy in adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation.

METHODS

This is the study protocol for a systematic review. We will search MEDLINE, EMBASE, Web of Science, and the Cochrane Library (from January 1980 onwards). We will include randomized controlled trials, quasi-experimental studies (non-randomized, interrupted time series), and observational studies (e.g., cohort studies and case-control studies), examining the efficacy of extracranial-intracranial bypass surgery compared to other treatments for adult patients with occlusive atherosclerotic disease of anterior cerebral circulation. Two team members will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The primary outcome will include stroke or death. The secondary outcomes will include intracranial hemorrhage, transient ischemic attack, and myocardial infarction. The study methodological quality (or bias) will be appraised using appropriate tools. If feasible, we will conduct random effects meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., study design, geographical location, or risk of bias).

DISCUSSION

This review will evaluate the evidence on the efficacy of extracranial-intracranial bypass surgery for adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation. We anticipate that our findings will be of interest to patients, their families, caregivers, healthcare professionals, and in making optimal treatment selection. Implications for future clinical and epidemiological research will be discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018105513.

Treatment of chronic internal carotid artery occlusion by ipsilateral external carotid endarterectomy

Chronic complete occlusion of the internal carotid artery (ICA) is a common and important cause of ischemic cerebrovascular disease, which can be treated in many ways: antithrombotic and anticoagulant agents, direct or indirect procedure for revascularization. However, there is still no evidence to prove which method is the most effective. Here we reported a case showed the successful endarterectomy of the external carotid artery (ECA) for a chronic complete occlusion of ICA patient. A 50-year-old male patient presented with progressively aggravated left-sided limb weakness and limb cold feeling. Digital subtraction angiography (DSA) showed ICA occlusion and ipsilateral ECA stenosis. The right ECA compensated for blood supply to the middle cerebral artery (MCA) through the accessory meningeal artery and ophthalmic artery. The patient was treated by endarterectomy of ipsilateral ECA (ECEA). In the second day after operation, the symptom was improved significantly. Surprisingly, both ICA and ECA were recanalized and the metabolism of the affected brain tissue was also increased. In conclusion, patients with chronic complete occlusion, ECEA would also be an effective therapeutic method.

Current Open Surgical Indications for Revascularization in Cerebral Ischemia

Cerebral revascularization was pioneered half a century ago. Gradual improvements in microsurgical instrumentation and training in microsurgical techniques have allowed significant changes that improved outcomes in neurosurgery, extrapolating this knowledge to other neurosurgical diseases (brain tumor, aneurysms, and skull base tumor surgery). But the popularity of cerebral bypass procedures was followed by their decline, given the lack of clear benefit of bypass surgery in chronic cerebrovascular ischemia after the EC-IC bypass studies. Over the last couple of decades, the formidable advance of neuro-endovascular techniques for revascularization has lessened the need for application of open cerebral revascularization procedures, either for flow augmentation or flow replacement. However, there is still a select group of patients with chronic cerebral ischemia, for whom open cerebral revascularization with flow augmentation is the only treatment option available, and this will be the objective of our current review.

Positional transient loss of consciousness and hemispheric deficits in the setting of severe four-vessel extracranial cerebrovascular disease

Carotid artery stenosis typically causes hemispheric neurologic effects by atheroembolism. Nonhemispheric symptoms, such as syncope, are generally not attributable to extracranial carotid disease. This report describes a 62-year-old woman with severe bilateral carotid artery stenosis, right vertebral artery occlusion, and severe left vertebral artery stenosis who presented with transient loss of consciousness and unilateral weakness when upright. Her symptoms resolved after right carotid endarterectomy. Whereas vertebrobasilar insufficiency alone can cause syncope, in the case of severe multivessel cerebrovascular disease, unilateral carotid revascularization was successful in treating the patient's transient loss of consciousness, suggesting global cerebral hypoperfusion as the cause.

Interventional recanalization as a treatment of carotid stump syndrome caused by right internal carotid artery occlusion: A case report

RATIONALE

Carotid stump syndrome is a cerebral infarction caused by an embolus formed subsequent to the vortex of blood flow from the occluded stump, which then moves through the collateral vessels into the brain. The covered stent and stent-assisted coil embolization stump are the effective interventions for the carotid artery stump.

PATIENT CONCERNS

A 71-year-old man twice experienced left limb weakness; diffusion weighted imaging confirmed the diagnosis of cerebral infarction. Cervical computed tomography angiography, intracranial magnetic resonance angiography, and digital subtraction angiography were conducted to evaluate collateral circulation, intraluminal composition, and shape of the carotid stump.

DIAGNOSES

The patient was diagnosed with cerebral infarction and right carotid stump syndrome.

INTERVENTION

The patient underwent interventional recanalization of the occluded internal carotid artery, which relieved his symptoms and led to satisfactory therapeutic outcomes during the clinical follow-up.

OUTCOMES

A 9-month clinical follow-up revealed no stroke recurrence.

LESSONS

Interventional recanalization for the carotid artery stump syndrome is feasible. Accurate preoperative evaluation including collateral circulation, intraluminal composition, and shape of the carotid stump can assure a successful vascularization and guided management.

Effect of bilateral carotid occlusion on cerebral hemodynamics and perivascular innervation: An experimental rat model

We aimed to investigate the effect of chronic cerebral hypoperfusion on cerebral hemodynamics and perivascular nerve density in a rat model. Bilateral common carotid artery (CCA) ligation (n = 24) or sham‐operation (n = 24) was performed with a 1‐week interval. A subgroup (ligated n = 6; sham‐operated n = 3) underwent magnetic resonance imaging (MRI) before the procedures and 2 and 4 weeks after the second procedure. After termination, carotids were harvested for assessment of complete ligation and nerve density in cerebral arteries that were stained for the general neural marker PGP 9.5 and sympathetic marker TH by computerized image analysis. Five rats were excluded because of incomplete ligation. MRI‐based tortuosity of the posterior communicating artery (Pcom), first part of the posterior cerebral artery (P1) and basilar artery was observed in the ligated group, as well as an increased volume (p = 0.05) and relative signal intensity in the basilar artery (p = 0.04; sham‐group unchanged). Immunohistochemical analysis revealed that compared to sham‐operated rats, ligated rats had increased diameters of all intracircular segments and the extracircular part of the internal carotid artery (p < 0.05). Ligated rats showed a higher general nerve density compared to controls in P1 (10%, IQR:8.7–10.5 vs. 6.6%, IQR:5.5–7.4, p = 0.003) and Pcom segments (6.4%, IQR:5.8–6.5 vs. 3.2%, IQR:2.4–4.3, p = 0.003) and higher sympathetic nerve density in Pcom segments (3.7%, IQR:2.8–4.8 vs. 1.7%, IQR:1.3–2.2, p = 0.02). Bilateral CCA occlusion resulted in redistribution of blood flow to posteriorly located cerebral arteries with remarkable changes in morphology and perivascular nerve density, suggesting a functional role for perivascular nerves in cerebral autoregulation.

A Modified Encephalo-Duro-Synangiosis Technique Induced Neovascularization in Symptomatic Atherosclerotic Carotid Artery Occlusion: A Phase I trial

OBJECTIVE

To the best of our knowledge, the present study is the first to assess the safety and feasibility of a modified encephalo-galeo-duro-synangiosis operation in patients with atherosclerotic carotid artery occlusion.

METHODS

Eight patients who had experienced new ipsilateral cerebrovascular events after the diagnosis of carotid artery occlusion were recruited. To facilitate extracranial-to-intracranial collateralization, 5 or 6 burr holes were made, and the dura mater and arachnoid were opened. The patients were closely monitored for complications and underwent conventional angiography, magnetic resonance imaging, and perfusion-weighted magnetic resonance imaging at baseline and 1 year of follow-up. After 10 years, the patients who were still alive were interviewed and assessed for functional outcomes and neurological status.

RESULTS

No surgery-related adverse events were observed, apart from temporary headache and subcutaneous effusion. Four of six patients had developed an extracranial-to-intracranial collateral blood vessels on angiography, and these patients had no incident ischemic events during the follow-up period. During the long-term follow-up period (10 years), 3 patients had died. Of those living, 4 of the 5 patients reported total resolution of the symptoms, with no incident ischemic events. One patient still experienced disability from an ischemic stroke that occurred as a result of the 1-year follow-up angiography.

CONCLUSIONS

Encephalo-duro-galeo-synangiosis for symptomatic carotid occlusion seems to be safe and feasible and might be able to induce extracranial-to-intracranial collaterals in patients with carotid artery occlusion. Further studies are needed to define the optimal therapeutic window and yield of burr hole surgery in the treatment of symptomatic carotid occlusive disease as an adjuvant to extracranial-intracranial bypass.

Long-term Outcomes After Endovascular Recanalization in Patients with Chronic Carotid Artery Occlusion

Successful carotid artery stenting may correct ipsilateral hemisphere hypoperfusion and improve neurocognitive function in patients with chronic internal carotid artery occlusion (ICAO). Its effect on long-term outcomes, however, has never been studied. From May 2004 to April 2015, endovascular recanalization for chronic ICAO was attempted in 118 consecutive patients (119 lesions; 98 men; 67 ± 10 years old) with either recurrent neurologic events or objectively impaired ipsilateral hemisphere perfusion. Technical success in recanalization was achieved in 70 lesions (59%, 70/119). 3-months cumulative any stroke or death rate was 5% (6/119; 4 in recanalized group, 2 in failure group), including 2 periprocedural ischemic stroke, 2 intracranial hemorrhage, and 2 subarachnoid hemorrhage. In recanalized patients without periprocedural complication, 1-year reocclusion rate was 15% (10/65). Up to 7 years after procedure, cumulative events of transient ischemic attack (TIA), or any stroke, or death were 17 in recanalized group, compared with 23 in failure group (hazard ratio 0.51, 95% confidence interval 0.27 to 0.97; p = 0.04). The difference became more significant after excluding patients with periprocedure events (hazard ratio 0.41, 95% confidence interval 0.20 to 0.84, p = 0.015). In conclusions, the technical success and periprocedural complication rates of endovascular recanalization for chronic ICAO were acceptable. The cumulative event rates of any stroke or death up to 7 years were more favorable in patients after successful recanalization, compared to those in patients after failed procedure.

Characterization and Natural History of Patients with Internal Carotid Occlusion: A Comparative Study

BACKGROUND

To characterize patients with internal carotid occlusion (ICO) with respect to demographic data, associated diseases, medical management, and risk factors and to compare these patients with those with nonsignificant stenosis (NSS; less than 50% stenosis). Secondary end points were new neurologic events, progression of contralateral degree of stenosis, cardiovascular symptoms, and death during follow-up.

METHODS

Retrospective analysis was performed using data collected from clinical records and added to a prospective database. Missing data were obtained during phone interviews or requested medical appointments.

RESULTS

From 2005 to 2013, 213 patients with ICO and 172 with NSS were studied (medium follow-up 37.81 months). Among the patients with ICO, a greater proportion were men, had a history of smoking, and presented with peripheral arterial disease and a lower creatinine clearance compared with those with NSS (P < 0.05). At the time of diagnosis, 76.1% of the patients with ICO were symptomatic compared with 35.5% of those with NSS (P = 0.000001). The patients in the ICO group exhibited significant progression of contralateral stenosis compared with those in the control group with progression on any side (15.0% vs. 2.3%, P = 0.00011). In addition, 18 patients in the ICO group (8.5%) exhibited new neurological symptoms compared with 13 (7.6%) in the NSS group (P = 0.41). When the ICO and NSS groups were combined, 10.8% of the initially symptomatic patients presented with new symptoms compared with 4.3% of those who were initially asymptomatic (P = 0.0218). The number of deaths was significantly higher among the patients in the ICO group (14.1% vs. 6.4%, P = 0.0150).

CONCLUSIONS

Patients presenting with ICO have more risk factors and higher mortality by any cause. Initially, symptomatic patients will likely present with more neurological symptoms during follow-up, independent of carotid morphology, ICO, or NSS. Efforts must be made to identify those at risk before occlusion and to prevent secondary events and death.

Prediction of Borderzone Infarction by CTA in Patients Undergoing Carotid Embolization for Carotid Blowout

BACKGROUND AND PURPOSE

Permanent common carotid artery and/or ICA occlusion is an effective treatment for carotid blowout syndrome. Besides postoperative thromboembolic infarction, permanent common carotid artery and/or ICA occlusion may cause borderzone infarction when the collateral flow to the deprived brain territory is inadequate. In this study, we aimed to test the predictive value of CTA for post-permanent common carotid artery and/or ICA occlusion borderzone infarction in patients with carotid blowout syndrome.

MATERIALS AND METHODS

In this retrospective study, we included 31 patients undergoing unilateral permanent common carotid artery and/or ICA occlusion for carotid blowout syndrome between May 2009 and December 2016. The vascular diameter of the circle of Willis was evaluated using preprocedural CTA, and the risk of borderzone infarction was graded as very high risk, high risk, intermediate risk, low risk, and very low risk.

RESULTS

The performance of readers' consensus on CTA for predicting borderzone infarction was excellent, with an area under receiver operating characteristic curve of 0.938 (95% confidence interval, 0.85-1.00). We defined very high risk, high risk, and intermediate risk as positive for borderzone infarction, the sensitivity, specificity, positive predictive value, and negative predictive value of CTA for borderzone infarction were 100% (7/7), 62.5% (15/24), 43.8% (7/16), and 100% (15/15), respectively. The interobserver reliability was excellent (κ = 0.807). No significant difference in the receiver operating characteristic curves was found between the 2 readers (P = .114).

CONCLUSIONS

CTA can be used to predict borderzone infarction after permanent common carotid artery and/or ICA occlusion by measuring the collateral vessels of the circle of Willis.

Risk of subsequent stroke, with or without extracranial-intracranial bypass surgery: a nationwide, retrospective, population-based study

OBJECTIVE

Although no benefits of extracranial-intracranial (EC-IC) bypass surgery in preventing secondary stroke have been identified previously, the outcomes of initial symptomatic ischemic stroke and stenosis and/or occlusion among the Asian population in patients with or without bypass intervention have yet to be discussed. The authors aimed to evaluate the subsequent risk of secondary vascular disease and cardiac events in patients with and without a history of this intervention.

METHODS

This retrospective nationwide population-based Taiwanese registry study included 205,991 patients with initial symptomatic ischemic stroke and stenosis and/or occlusion, with imaging data obtained between 2001 and 2010. Patients who underwent EC-IC bypass (bypass group) were compared with those who had not undergone EC-IC bypass, carotid artery stenting, or carotid artery endarterectomy (nonbypass group). Patients with any previous diagnosis of ischemic or hemorrhagic stroke, moyamoya disease, cancer, or trauma were all excluded.

RESULTS

The risk of subsequent ischemic stroke events decreased by 41% in the bypass group (adjusted hazard ratio [HR] 0.59, 95% CI 0.46-0.76, p < 0.001) compared with the nonbypass group. The risk of subsequent hemorrhagic stroke events increased in the bypass group (adjusted HR 2.47, 95% CI 1.67-3.64, p < 0.001) compared with the nonbypass group.

CONCLUSIONS

Bypass surgery does play an important role in revascularization of the ischemic brain, while also increasing the risk of hemorrhage in the early postoperative period. This study highlights the fact that the high risk of bypass surgery obscures the true benefit of revascularization of the ischemic brain and also emphasizes the importance of developing improved surgical technique to treat these high-risk patients.

[Carotid endarterectomy in patients with symptomatic occlusions of the contralateral internal carotid artery]

The main aim of the study was to investigate the effect of carotid endarterectomy on the prognosis of chronic cerebral ischemia in patients with symptomatic occlusions of the contralateral internal carotid artery, assess risks of surgical complications, and substantiate the staged surgical approach for treatment of patients with this pathology. The article analyzes the experience in surgical treatment of 83 patients with symptomatic ICA occlusions who underwent surgery for contralateral carotid artery stenosis. In 40 patients, only carotid endarterectomy (CEA) was performed on the side of hemodynamically significant stenosis (group 1). In 43 (52%) cases, apart from CEA, extracranial-intracranial (EC-IC) bypass was performed at the second stage (23 cases, group 2) or the first stage (19 cases, group 3). A surgical treatment approach was chosen based on clinical symptoms, severity of contralateral carotid artery stenosis, and the magnitude of perfusion deficiency in the territory of carotid occlusion. The conducted analysis revealed that patients with symptomatic occlusions and contralateral carotid artery stenoses represented a heterogeneous group with a different efficacy of carotid endarterectomy and with risks of perioperative complications. As cerebrovascular insufficiency in the territory of carotid occlusion and a related neurological deficit worsen, the risks of complications of contralateral carotid endarterectomy increase, and its clinical efficacy decreases. In these cases, cerebral revascularization on the ICA occlusion side should be performed at the first stage.

Predictors for Successful Endovascular Intervention in Chronic Carotid Artery Total Occlusion

OBJECTIVES

This study sought to determine predictors for successful endovascular treatment in patients with chronic carotid artery occlusion (CAO).

BACKGROUND

Endovascular recanalization in patients with chronic CAO has been reported to be feasible, but technically challenging.

METHODS

Endovascular attempts in 138 consecutive chronic CAO patients with impaired ipsilateral hemisphere perfusion were reviewed. We analyzed potential variables including epidemiology, symptomatology, angiographic morphology, and interventional techniques in relation to the technical success.

RESULTS

The technical success rate was 61.6%. Multivariate analysis showed absence of prior neurologic event (odds ratio [OR]: 0.27; 95% confidence interval [CI]: 0.10 to 0.76), nontapered stump (OR: 0.18; 95% CI: 0.05 to 0.67), distal internal carotid artery (ICA) reconstitution via contralateral injection (OR: 0.19; 95% CI: 0.05 to 0.75), and distal ICA reconstitution at communicating or ophthalmic segments (OR:0.12; 95% CI: 0.04 to 0.36) to be independent factors associated with lower technical success. Point scores were assigned proportional to model coefficients, and technical success rates were >80% and <40% in patients with scores of ≤1 and ≥4, respectively. The c-indexes for this score system in predicting technical success was 0.820 (95% CI: 0.748 to 0.892; p < 0.001) with a sensitivity of 84.7% and a specificity of 67.9%.

CONCLUSIONS

Absence of prior neurologic event, nontapered stump, distal ICA reconstitution via contralateral injection, and distal ICA reconstitution at communicating or ophthalmic segments were identified as independent negative predictors for technical success in endovascular recanalization for CAO.

Effect of acupuncture on cerebrovascular reserve in patients with acute cerebral infarction: protocol for a randomized controlled pilot study

BACKGROUND

The incidence of cerebral infarction has been growing year by year in China and around the world. According to clinical observation, acupuncture utilizing the "waking up the spirit" needling method is widely used in patients with cerebral infarction, though the underlying mechanisms remain unclear. Additionally, a number of studies have begun to focus on the relationship between cerebrovascular reserve (CVR) and cerebral infarction. The present study aims to investigate whether CVR is one of potential mechanisms underpinning this effect of acupuncture on patients with cerebral infarction.

METHODS

This is a single-centre, prospective, single-blinded, randomized controlled pilot study. Sixty eligible patients will be randomized into an intervention group (waking up the spirit acupuncture) and a control group (hand and foot 12-meridian acupuncture) in a 1:1 ratio. All treatments will be conducted once a day on weekdays followed by a 2-day rest period on the weekend, over a total treatment course of 2 weeks. The primary outcome measures are cerebrovascular reserve (CVR) capacity and Breath-holding Index (BHI) which will be evaluated at baseline and 2 weeks after the first acupuncture treatment, and the secondary outcome measures are National Institutes of Health Stroke Scale (NIHSS) and Barthel Index scores which will be used to further evaluate the efficacy of the intervention.

DISCUSSION

Cerebrovascular reserve is an independent risk factor for the occurrence, progression, and recurrence of cerebral infarction that requires attention. This trial aims to investigate whether acupuncture utilizing the waking up the spirit needling method can improve CVR capacity in patients with acute cerebral infarction, thus reducing NIHSS scores and preventing further progression of the disease. Furthermore, data and evidence gained from this study will be utilized in the development of future research projects regarding the effects of acupuncture in patients with acute cerebral infarction.

TRIAL REGISTRATION

ISRCTN, ID: ISRCTN99117074 . Registered on 20 April 2016.

Early risk of recurrent stroke in patients with symptomatic carotid near-occlusion: Results from CAOS, a multicenter registry study

Background

The risk of recurrent stroke among patients with symptomatic carotid near-occlusion is not well established, and management of the condition remains controversial. Symptomatic carotid near-occlusion with full collapse has been identified as a strong predictor of early recurrence. We aimed to analyze the 90-day risk of recurrent ipsilateral ischemic stroke in medically treated patients with symptomatic carotid near-occlusion.

Methods

We performed a multicenter, nationwide, prospective study from January 2010 to May 2016. Patients with angiography-confirmed symptomatic carotid near-occlusion were included. The primary endpoint was ipsilateral ischemic stroke or transient ischemic attack (TIA) within 90 days after the presenting event. For this analysis, patients who underwent revascularization within 90 days after stroke were excluded.

Results

The study population comprised 141 patients from 17 Spanish centers; 83 patients were treated medically. Primary endpoint occurred in eight patients, resulting in a cumulative rate of 10.6% (95% CI, 3.7–17.5). Previous history of stroke or transient ischemic attack was identified as an independent predictor for recurrence in the multivariate Cox regression analysis (HR, 4.37 [95% CI, 1.05–18.18]; p = 0.043), while the presence of full collapse was not associated with an increased risk (HR, 0.81 [95% CI, 0.17–3.92]; p = 0.793). The risk of recurrence was also not affected by the presence of significant stenosis or occlusion of the contralateral carotid artery, or by the collateral circulation.

Conclusions

Patients with symptomatic carotid near-occlusion seem to have an increased risk of early ipsilateral recurrent stroke. Our results contrast with the low risk of symptomatic carotid near-occlusion reported to date. Full collapse did not increase the risk of recurrent stroke in our study.

The cerebral circulation and cerebrovascular disease II: Pathogenesis of cerebrovascular disease

In this paper, we review the cerebral circulation and cerebrovascular disease (CVD) with an overview of the major types of CVD pathogenesis. These, as categorized here, are as follows: occlusive injury intrinsic to blood vessels, occlusive injury extrinsic to blood vessels, cerebral hypoperfusion, and cerebral hemorrhage. Following an overview of each of these categories, we conclude with a discussion of cerebral edema to illustrate how the pathological origins we covered can progress clinically. The content of this paper sets the stage for the detailed, clinically oriented discussion of stroke with which our series culminates in its subsequent Part III.

Effects of Obstructive Carotid Artery Disease on Ocular Circulation and the Safety of Carotid Artery Stenting

BACKGROUND

The aims of this study were to examine the ophthalmic artery flow changes in patients with obstructive carotid artery disease, evaluate the orbital blood flow changes after carotid artery stenting and assess the safety of carotid stenting procedure by using transorbital colour and spectral Doppler sonography.

METHODS

Thirty-one consecutive patients scheduled for carotid stenting with severe internal carotid artery stenosis (>60%; the study group) and 30 control subjects were included. Ophthalmic artery (OA) Doppler sonography was performed in the control group and study group before and after stenting. Peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) and systolic/diastolic ratio (S/D) in the ophthalmic artery were recorded. Statistical comparisons were made between controls and study group before stenting and before and after stenting in the study group.

RESULTS

Comparison between control and study group before stenting revealed a statistically significant decrease in OA PSV (51.5±14.5 vs. 39.7±19cm/sec, p= 0.008) and EDV (15.2±4.5 vs. 11.3±5.7cm/sec, p=0.004) in the study group. Differences in PI (1.3±0.14 vs. 1.36±0.4, p=0.47), RI (0.7±0.04 vs. 0.75±0.21, p=0.19), and S/D (3.5±0.6 vs. 3.6±1, p= 0.5) ratio were not statistically significant between groups. Peak systolic velocity (39.7±18.9 vs. 51.3±22.2cm/sec, p <0.001), RI (0.75±0.21 vs. 0.81±0.13, p=0.16) and S/D ratio (3.6±1 vs. 4.6±1.5, p= 0.001) were found to be significantly increased in the study group after stenting compared to baseline. There were no statistically significant differences in EDV and RI EDV(11.3±5.7 vs. 11.7±5.7cm/sec, p=0.66), PI (1.36±0.4 vs. 1.6±0.6, p =0.047) after stenting.

CONCLUSIONS

Ophthalmic artery flow parameters were significantly lower in patients with severe carotid artery stenosis compared to control, indicating compromised ocular blood flow in severe carotid stenosis. Flow indicators significantly improved after stent implantation suggesting the importance of revascularisation in restoring ocular blood flow and safety of carotid stenting.

Acetazolamide-augmented dynamic BOLD (aczBOLD) imaging for assessing cerebrovascular reactivity in chronic steno-occlusive disease of the anterior circulation: An initial experience

The purpose of this study was to measure cerebrovascular reactivity (CVR) in chronic steno-occlusive disease using a novel approach that couples BOLD imaging with acetazolamide (ACZ) vasoreactivity (aczBOLD), to evaluate dynamic effects of ACZ on BOLD and to establish the relationship between aczBOLD and dynamic susceptibility contrast (DSC) perfusion MRI. Eighteen patients with unilateral chronic steno-occlusive disease of the anterior circulation underwent a 20-min aczBOLD imaging protocol, with ACZ infusion starting at 5 min of scan initiation. AczBOLD reactivity was calculated on a voxel-by-voxel basis to generate CVR maps for subsequent quantitative analyses. Reduced CVR was observed in the diseased vs. the normal hemisphere both by qualitative and quantitative assessment (gray matter (GM): 4.13% ± 1.16% vs. 4.90% ± 0.98%, P = 0.002; white matter (WM): 2.83% ± 1.23% vs. 3.50% ± 0.94%, P = 0.005). In all cases BOLD signal began increasing immediately following ACZ infusion, approaching a plateau at ~ 8.5 min after infusion, with the tissue volume of reduced augmentation increasing progressively with time, peaking at 2.60 min (time range above 95% of the maximum value: 0–4.43 min) for the GM and 1.80 min (time range above 95% of the maximum value: 1.40–3.53 min) for the WM. In the diseased hemisphere, aczBOLD CVR significantly correlated with baseline DSC time-to-maximum of the residue function (T_max) (P = 0.008 for the WM) and normalized cerebral blood flow (P = 0.003 for the GM, and P = 0.001 for the WM). AczBOLD provides a novel, safe, easily implementable approach to CVR measurement in the routine clinical environments. Further studies can establish quantitative thresholds from aczBOLD towards identification of patients at heightened risk of recurrent ischemia and cognitive decline.

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A method coupling BOLD with ACZ challenge (aczBOLD) for CVR assessment was proposed.

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Compromised CVR was detected in patients with cerebrovascular disease.

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Dynamic effects of ACZ on BOLD were characterized.

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CVR correlated with baseline dynamic susceptibility contrast perfusion MRI.

Internal Carotid Artery Occlusion: Association With Atherosclerotic Disease in Other Arterial Beds and Vascular Risk Factors

The aim of this article is to investigate the association between internal carotid artery occlusion (ICAO) and the presence of atherosclerotic disease and vascular risk factors. The clinical characteristics and risk factors of 120 patients presenting with ICAO were retrospectively reviewed. All patients (n = 120) had at least 1 of the 4 vascular risk factor (diabetes, smoking, hypercholesterolemia, and hypertension); 2, 3, or all 4 risk factors were present in 14 to 82 of the patients (11.7% to 68.3%), 10 to 39 of the patients (8.3% to 32.5%), and 9 of the patients (7.5%), respectively. A total of 84 patients (70%) with ICAO had disease in at least 1 additional vascular bed (aorta, coronary or lower limb arteries). In addition to ICAO, vascular disease was present in 2 and all 3 of these arterial beds in 42 (35%) and 9 (7.5%) patients, respectively. Furthermore, stenosis or occlusion of the ipsilateral or contralateral vertebral arteries was recorded in 19 of 120 patients (15.8%). Regarding the contralateral carotid artery, 1 patient had bilateral ICAO. One patient had contralateral common carotid artery occlusion, and 1 patient was excluded from the analysis because of surgery to the contralateral carotid artery. Of the remaining 117 patients, 34 (29.0%) had less than 50% contralateral carotid artery stenosis. Thirty-two patients (27.4%) had 50% to 69%, and 51 (43.6%) had 70% to 99% stenosis. Ultrasonographic imaging of the carotid plaque of the contralateral carotid artery revealed that 52 of the 120 arteries (43.3%) were uniformly or predominantly echolucent (types I and II, respectively). Fifty-nine (49.2%) were predominantly or uniformly echogenic (types III and IV), and 9 (7.5%) could not be classified. A similar distribution of echomorphology was observed on the occluded side. ICAO is associated with widespread atherosclerotic disease and a high prevalence of vascular risk factors. Detection of ICAO should prompt the investigation of other arterial beds and treatment of risk factors.

Predicting procedure successful rate and 1-year patency after endovascular recanalization for chronic carotid artery occlusion by CT angiography

BACKGROUND

Proper patient selection criteria for treatment of carotid chronic total occlusion (CTO) are unclear. This study was designed to predict procedure successful rate and 1-year patency after carotid artery stenting (CAS) for carotid CTO using pre-procedural CTA.

METHODS

Patients with CTO detected on CTA who underwent recanalization within 3months were divided into those with occlusions at (or distal to) the clinoid segment of the internal carotid artery (group A) and those with occlusions proximal to the clinoid segment (group B) and outcomes were compared between groups.

RESULTS

Technical success rates, major complications, and re-occlusions within 1-year were 52%, 22%, 91% in group A (N=23), and 89%, 0%, 0% in group B (N=19), respectively. Diabetes was more frequent in group A (43%) compared with group B (11%).

CONCLUSION

CTA may play a role in predicting successful rate and 1-year patency for endovascular recanalization in carotid CTO.

Bypass surgery for the prevention of ischemic stroke: current indications and techniques

INTRODUCTION

Although most ischemic strokes are thromboembolic in origin and their management is endovascular or medical, some are haemodynamic in origin and their management may be surgical. We reviewed bypass indications, patient selection and surgical techniques used in our current practice.

METHODS

Extracranial-intracranial (EC-iC) bypass with superior temporal artery-to-middle cerebral artery (STA-MCA) bypass, high-flow interposition grafts and reconstructive techniques were used to treat patients with symptomatic ischemia.

RESULTS

During a 13-year period, 152 bypasses were performed for ischemia in 129 patients. Specific diagnoses included: (1) internal carotid artery (iCA) occlusion (58 bypasses); (2) MCA occlusion and, rarely, high-grade MCA stenosis (22 bypasses); (3) vertebrobasilar atherosclerotic steno-occlusive disease (2 bypasses); (4) moyamoya disease (65 bypasses); and (5) ischemic complications after aneurysm treatment (5 bypasses). of the 152 bypasses, 137 were conventional STA-MCA bypasses. fourteen patients had high-flow bypasses that included 4 "double-barrel" STA-MCA bypasses, 6 bypasses with interposition grafts to the cervical carotid artery, 2 subclavian artery-to-MCA bypasses, 1 MCA-to-posterior cerebral artery (PCA) bypass and 1 aorto-carotid bypass. The bypass patency rate was 96.1%.

CONCLUSIONS

Bypass surgery for the prevention of ischemic stroke is safe and elegant techniques have been developed. Patients with athero-occlusive disease, ischemic symptoms and haemodynamic insufficiency have significant risk of stroke if managed medically or left untreated. However, surgical intervention lacks supporting evidence from the recent Carotid occlusion Surgery Study (CoSS). Patients will be caught in a difficult position between a dismal natural history and an unproven surgical intervention. Clinicians must individualise their management until additional data are published or further consensus develops.