Hemodynamic contribution of transdural collateral flow in adult patients with moyamoya disease

Revascularisation patterns and characteristics after erythropoietin pretreatment and multiple burr holes in patients who had acute stroke with perfusion impairment

BACKGROUND

Transdural collaterals, originating mainly from the extracalvarial superficial temporal artery and intracalvarial middle meningeal artery via the external carotid artery (ECA), have been observed after revascularisation surgery. However, the origin of these collaterals in patients with stroke with perfusion insufficiency is not yet known. Therefore, we studied the revascularisation patterns and characteristics based on the origin of these collaterals.

METHODS

We employed erythropoietin pretreatment and performed multiple burr holes under local anaesthesia to achieve transdural revascularisation in patients with acute stroke with perfusion insufficiency. After 6 months, we reassessed the transfemoral cerebral angiography to evaluate the revascularisation patterns. The collaterals were categorised into intracalvarial ECA-dominant (originating from the middle meningeal artery), extracalvarial ECA-dominant (originating from the superficial temporal or occipital artery) and balanced groups. We compared various imaging parameters among these groups.

RESULTS

Overall, 87 patients with 103 treated hemispheres were involved. Among them, 57.3% were classified as intracalvarial ECA-dominant, 20.4% as extracalvarial ECA-dominant and 22.3% as balanced. Most of the hemispheres with intracalvarial or extracalvarial collaterals (vs balanced collaterals) showed successful revascularisation (78/80 (97.5%) vs 12/23 (52.1%)), p<0.001). In ultrasonographic haemodynamic changes according to revascularisation pattern, only the intracalvarial ECA-dominant revascularisation was significantly associated with specific changes in ECA blood flow, leading to the conversion to a low-resistance ECA Doppler sonography waveform.

CONCLUSIONS

Our findings suggest that intracalvarial ECA-dominant revascularisation plays a crucial role in the formation of transdural collaterals following combined therapy. These distinct changes in ECA haemodynamics can be non-invasively identified through bedside ultrasound studies.

[Variants of collateral cerebral circulation in moyamoya disease]

BACKGROUND

Moyamoya disease is a chronic progressive cerebrovascular disease with a complex pathophysiology and unique features of neoangiogenesis. These features are still known only to a few specialists, although they determine clinical course and outcomes of disease.

OBJECTIVE

To determine the nature and degree of neoangiogenesis in restructuring the natural collateral circulation in patients with moyamoya disease and its effect on cerebral blood flow. The influence of collateral circulation on postoperative results and factors of its effectiveness will be analyzed in the 2nd part of the study.

MATERIAL AND METHODS

The study included 65 patients with moyamoya disease who underwent preoperative selective direct angiography with separate contrast enhancement of both internal, external and vertebral arteries. We analyzed 130 hemispheres. Suzuki stage of disease, pathways of collateral circulation and their relationship with reduction of cerebral blood flow and clinical manifestations were assessed. Distal vessels of the middle cerebral artery (MCA) were additionally studied.

RESULTS

Suzuki stage 3 was the most common (36 hemispheres, 38%). Leptomeningeal collaterals were the most common among intracranial collateral tracts (82 hemispheres, 66.1%). Extra-intracranial transdural collaterals were found in half of the cases (56 hemispheres). We observed certain changes in distal vessels of the MCA (hypoplasia of M3 branches) in 28 (20.9%) hemispheres. Suzuki stage of disease significantly determined degree of cerebral blood flow insufficiency, i.e. more severe perfusion deficit was observed at the later stages of disease. A well-developed system of leptomeningeal collaterals significantly reflected stages of compensation and subcompensation of cerebral blood flow according to perfusion data (χ2=20.394, p<0.001).

CONCLUSION

Neoangiogenesis is a natural compensatory mechanism in moyamoya disease designed to maintain brain perfusion under reduced cerebral blood flow. Predominant intra-intracranial collaterals are associated with ischemic and hemorrhagic events. Timely restructuring on extra-intracranial ways of collateral circulation prevents adverse manifestations of disease. Assessment and understanding of collateral circulation in patients with moyamoya disease create the prerequisites for substantiating the method of surgical treatment.

Transdural Revascularization by Multiple Burrhole After Erythropoietin in Stroke Patients With Cerebral Hypoperfusion: A Randomized Controlled Trial

In patients with acute symptomatic stroke, reinforcement of transdural angiogenesis using multiple burr hole (MBH) procedures after EPO (erythropoietin) treatment has rarely been addressed. We aimed to investigate the efficacy and safety of cranial MBH procedures under local anesthesia for augmenting transdural revascularization after EPO treatment in patients with stroke with perfusion impairments.

Use of Intraoperative Neuronavigation to Identify Transdural Collaterals in Moyamoya Vasculopathy: A Simple Way to Make It Safer

INTRODUCTION

Transdural collaterals (TC) from the external carotid artery must be preserved when operating on patients with moyamoya vasculopathy. Several techniques have been used to identify the superficial temporal artery (STA) and middle meningeal artery (MMA) during surgery and prevent their damage. However, the use of neuronavigation for this specific purpose has never been described in the literature. We describe an operative case in which neuronavigation was used to preserve the TC (originating from the MMA), detailing our technique step by step and reviewing alternative methods previously reported.

CASE PRESENTATION

A 6-year-old girl with moyamoya disease, who had developed marked bilateral TC from the MMA sparing the middle cerebral artery territory, underwent staged bilateral indirect revascularization surgery. Intraoperative neuronavigation was used to identify the STA and MMA with their main branches during skin incision, craniotomy, and dural opening. The neuronavigation matched the intraoperative findings exactly, and the target structures remained undamaged. The patient was discharged home after both surgeries with no neurological deficits. One year following surgery, the patient has excellent collateralization from both STAs and is asymptomatic and neurologically intact.

CONCLUSION

With the use of intraoperative neuronavigation, the STA, MMA, and their main branches, as well as their relationship to the bone, can be identified and preserved. This approach can help in preventing undesirable injury to TC during surgery and may potentially prevent perioperative stroke in patients with moyamoya vasculopathy undergoing revascularization surgery.

Clinical Significance of Ultrasound-Based Hemodynamic Assessment of Extracranial Internal Carotid Artery and Posterior Cerebral Artery in Symptomatic and Angiographic Evolution of Moyamoya Disease: A Preliminary Study

Objective: To investigate the hemodynamic changes using ultrasound according to digital subtraction angiography (DSA) findings and explore the association between ultrasound parameters and clinical symptoms of moyamoya disease (MMD). Methods: Hemodynamic parameters of extracranial internal carotid artery (EICA) and posterior cerebral artery (PCA) were evaluated by ultrasound. According to DSA findings, EICA parameters among Suzuki stages (stage I-II, III-IV, and V-VI), and PCA parameters among leptomeningeal system scores (score 0-2, 3-4, and 5-6) were compared, respectively. ROC analysis was performed based on the ultrasound parameters to distinguish stroke from non-stroke patients. Results: Forty patients with MMD were included in our study (16 men; median age, 37 years). The diameter (D), peak systolic velocity (PSV), end diastolic velocity (EDV) and flow volume (FV) of EICA decreased as the Suzuki stage advanced (D: P < 0.001; PSV: P < 0.001; EDV: P < 0.001; FV: P < 0.001). The PSV and EDV of PCA increased as the leptomeningeal system scores advanced (PSV: P < 0.001; EDV: P < 0.001). ROC analysis showed that the area under the curves (AUCs) based on the D and FV of EICA, the PSV and EDV of PCA and their combination were 0.688, 0.670, 0.727, 0.684, and 0.772, respectively, to distinguish stroke from non-stroke patients. Conclusions: Ultrasound parameters were related to Suzuki stages and leptomeningeal system scores. Ultrasound may be useful in predicting the occurrence of stroke in patients with MMD. Future prospective studies with large sample sizes and long-term follow-up are needed to confirm our preliminary findings.

Association Between Ultrasound Parameters and History of Ischemic or Hemorrhagic Stroke in Patients With Moyamoya Disease

Objective: To explore the association between ultrasound parameters and previous ischemic or hemorrhagic stroke in patients with moyamoya disease (MMD), and develop an ultrasound-based nomogram to identify stroke in patients with MMD.

Methods: We prospectively enrolled 52 consecutive patients (92 hemispheres) with MMD at the Beijing Tiantan Hospital. Thirty-six patients (65 hemispheres) were assigned to the training dataset from September 2019 to February 2020, and 16 patients (27 hemispheres) were assigned to the validation dataset from March 2020 to July 2020. Multivariate logistic regression analysis was applied to identify ultrasound parameters associated with previous history of ipsilateral stroke in patients with MMD, and a nomogram was subsequently constructed to identify stroke in patients with MMD. The performance of the nomogram was evaluated with respect to discrimination, calibration, and clinical usefulness.

Results: Multivariate analysis indicated that the flow volume (FV) of the extracranial internal carotid artery (EICA) and the peak systolic velocity (PSV) of the posterior cerebral artery (PCA) were independently associated with ipsilateral stroke in patients with MMD, a nomogram incorporating these two parameters was constructed to identify stroke patients. The area under the receiver operating characteristic (AUROC) curves was 0.776 (95% CI, 0.656–0.870) in the training dataset and 0.753 (95% CI, 0.550–0.897) in the validation dataset suggested that the model had good discrimination ability. The calibration plot showed good agreement in both the two datasets. The decision curve analysis (DCA) revealed that the nomogram was clinically useful.

Conclusions: Ultrasound parameters of EICA and PCA are independently associated with history of previous ipsilateral ischemic or hemorrhagic stroke in patients with MMD. The present ultrasound-based nomogram might provide information to identify MMD patients with high risk of stroke. Future long-term follow-up studies are needed to prove the predictive value in other independent cohorts.

Clinical Trial Registration:http://www.chictr.org.cn/index.aspx. Unique Identifier: ChiCTR1900026075.

Angiographic study of the transdural collaterals at the anterior cranial fossa in patients with Moyamoya disease

Unlike its parietal, temporal, and occipital counterparts, the frontal lobe has a broad basal surface directly facing the anterior cranial fossa dura mater which could permit establishment of transdural collaterals (TDCs) with the frontal lobe. Studies on the TDCs from the anterior cranial fossa in moyamoya disease (MMD) are scarce and inadequately investigated. A retrospective study of 100 hemispheres in 50 patients who were diagnosed with MMD by catheter angiography between January 2015 and June 2019 was performed in our institution. TDCs through the anterior ethmoid artery (AEA) or posterior ethmoid artery (PEA) were divided into 3 types respectively based on their respective angioarchitecture. Furthermore, we also studied TDCs to the temporal, parietal, and occipital lobes and collaterals from the posterior circulation to the territory of the anterior cerebral artery. TDCs through the AEA and PEA were identified in 89 (89/100, 89%) and 73 (73/100, 73%) of the hemispheres. The vascularization state of the frontal lobe was good in 89 (89/100, 89%) hemispheres. Rete mirabile and TDCs through the PEA were statistically different among patients with different Suzuki stages. No statistical difference was noted in TDCs through the AEA, frontal TDCs from other sources, and the vascularization state of the frontal lobe with regard to different Suzuki stages. TDCs through the AEA and PEA at the anterior cranial fossa play a very important role in compensating the ischemic frontal lobe. The frontal lobe could be well compensated in most of the patients with TDCs at the anterior cranial fossa.

Cranial burr hole with erythropoietin administration induces reverse arteriogenesis from the enriched extracranium

It is challenging to revitalize ischemic penumbra after an acute stroke with intracranial perfusion insufficiency. To evaluate whether cranial burr hole and erythropoietin (EPO) generate effective revascularization, we investigated the efficacy of the augmentation method for reverse arteriogenesis from the healthy extracranial milieu. An intracranial perfusion insufficiency was created through bilateral internal carotid artery ligation (bICAL) in Sprague-Dawley rats. We administered recombinant human EPO (5000 U/kg) or saline intraperitoneally for 3 days after bICAL. Mechanical barrier disruption (MBD) was performed through a cranial burr hole with small dural cracks in the right hemisphere. The ipsilateral hemisphere with MBD grossly showed vascular networks between the extra- and intra-cranial spaces 2 weeks after the MBD procedure. It also showed significantly increased vessels in the intracranial vasculature adjacent to the MBD region (p = 0.0006). The levels of pro-angiogenic and inflammatory factors with prominent markers of vessel permeability were also significantly increased (MBD-only vs. control; Tnf-α, p = 0.0007; Vegf, p = 0.0206). In the EPO-administered group, such elevations in inflammation were significantly mitigated (combined vs. MBD-only; Tnf-α, p = 0.0008). The ipsilateral hemisphere with MBD-EPO (vs. MBD-only) showed significantly increased vessels (RECA-1, p = 0.0182) and their maturation (RECA-1/α-SMA, p = 0.0046), with upregulation of tumor growth factor-β1 (Tgf-β1, p = 0.037) and matrix metalloproteinase-2 (Mmp-2, p = 0.0488). These findings were completely blocked by minocycline (MIC) administration during in vivo (Tgf-β1, p = 0.0009; Mmp-2, p < 0.0001) and in vitro experiments (tube formation, p < 0.0001). Our data suggest that the MBD procedure (for angiogenic routes) and EPO administration (for an arteriogenic booster) are complimentary and can facilitate successfully "reverse arteriogenesis" in subjects with intracranial perfusion insufficiency.

Feasibility of Multiple Burr Hole With Erythropoietin in Acute Moyamoya Patients

BACKGROUND AND PURPOSE

In patients with acute symptomatic moyamoya (<2 weeks), the feasibility of a combination therapy of multiple burr hole procedure under local anesthesia and intravenous erythropoietin pretreatment was assessed. We also identified the factors associated with transdural revascularization.

METHODS

In this prospective single-arm study, perfusion-impaired patients presenting with transient ischemic attack or acute cerebral infarction were assessed. Combination therapy was performed to patients lacking transdural collaterals. Primary outcomes were evaluated clinically with modified Rankin Scale scores and radiologically with revascularization success (transhemispheric, trans-burr hole, and sufficient revascularizations [filling ≥33% of ipsilateral supratentorium]) at 6 months. Treatment-related adverse events were analyzed in 3 phases: pre burr hole, post burr hole, and after-discharge as secondary outcome. Factors associated with sufficient revascularization were investigated.

RESULTS

Fifty hemispheres from 37 patients were included. Compared with discharge, modified Rankin Scale score at 6 months significantly improved (2.0 [0.0-5.0] versus 1.0 [0.0-4.0]; P<0.001). Majority had successful revascularization: trans-burr hole arteriogenesis (89.5%), transhemispheric arteriogenesis (98.0%), and sufficient revascularization (52.0%). There was no significant pre burr hole or post burr hole complication. Two (5.4%) transient ischemic attack and 1 (2.7%) cerebral infarction occurred after discharge. Presentation with acute infarction (odds ratio, 4.8; 95% confidence interval, 1.1-21.4), ipsilateral basal moyamoya vessels (odds ratio, 13.9; 95% confidence interval, 1.3-144.2), and delayed mean transit time (odds ratio, 3.9; 95% confidence interval, 1.3-12.2) predicted sufficient revascularization.

CONCLUSIONS

Combination therapy allows safe and effective revascularization in moyamoya patients with acute ischemic presentation.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03162588.