Baofeng Xu

Current status of the treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery: A review

Currently, the treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) is challenging and utilizes many therapeutic methods, including direct clipping and suturing, clipping after wrapping, clipping after suturing, coil embolization, stent-assisted coil embolization, multiple overlapping stents, flow-diverting stents, covered stents, and trapping with or without bypass. In these therapeutic approaches, the optimal treatment method for BBAs has not yet been defined based on the current understanding of BBAs of the supraclinoid ICA. Therefore, in this study, we aimed to review the literature from PubMed to discuss and analyze the pros and cons of the above approaches while adding our own viewpoints to the discussion. Among the surgical methods, direct clipping was the easiest method if the compensation of the collateral circulation of the intracranial distal ICA was sufficient or direct clipping did not induce stenosis in the parent artery. In addition, the clipping after wrapping technique should be chosen as the optimal surgical modality to prevent rebleeding from these lesions. Among the endovascular methods, multiple overlapping stents (≥3) with coils may be a feasible alternative for the treatment of ruptured BBAs. In addition, flow-diverting stents appear to have a higher rate of complete occlusion and a lower rate of retreatment and are a promising treatment method. Finally, when all treatments failed or the compensation of the collateral circulation of the intracranial distal ICA was insufficient, the extracranial-intracranial (EC-IC) arterial bypass associated with surgical or endovascular trapping, a complex and highly dangerous method, was used as the treatment of last resort.

Progress on Complications of Direct Bypass for Moyamoya Disease

Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD.

Current Understanding of Dolichoarteriopathies of the Internal Carotid Artery: A Review

Dolichoarteriopathies of the internal carotid artery (DICAs) are not uncommon, and although several studies have investigated DICAs, several questions regarding the etiology and best management course for DICAs remain unanswered. It is also difficult to correlate the occurrence of DICAs with the onset of clinical symptoms. Therefore, we surveyed the literature in PubMed and performed a review of DICAs to offer a comprehensive picture of our understanding of DICAs. We found that DICAs can be classified into three types, specifically tortuous, coiling and kinking, and are not associated with atherosclerotic risk factors. Cerebral hemodynamic changes are mainly associated with the degree of bending of DICAs. DICAs can result in symptoms of the brain and eyes due to insufficient blood supply and can co-occur with a pulsatile cervical mass, a pharyngeal bulge and pulsation. The diagnostic tools for the assessment of DICAs include Doppler ultrasonography, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA), and although DSA remains the gold standard, Doppler ultrasonography is a convenient method that provides useful data for the morphological evaluation of DICAs. CTA and MRA are efficient methods for detecting the morphology of the cervical segment of DICAs. Some DICAs should be treated surgically based on certain indications, and several methods, including correcting the bending or shortening of DICAs, have been developed for the treatment of DICAs. The appropriate treatment of DICAs results in good outcomes and is associated with low morbidity and mortality rates. However, despite the success of surgical reconstruction, an appropriate therapeutic treatment remains a subject of numerous debates due to the lack of multicentric, randomized, prospective studies.

Clinical importance of the middle meningeal artery: A review of the literature.

The middle meningeal artery (MMA) is a very important artery in neurosurgery. Many diseases, including dural arteriovenous fistula (DAVF), pseudoaneurysm, true aneurysm, traumatic arteriovenous fistula (AVF), moyamoya disease (MMD), recurrent chronic subdural hematoma (CSDH), migraine and meningioma, can involve the MMA. In these diseases, the lesions occur in either the MMA itself and treatment is necessary, or the MMA is used as the pathway to treat the lesions; therefore, the MMA is very important to the development and treatment of a variety of neurosurgical diseases. However, no systematic review describing the importance of MMA has been published. In this study, we used the PUBMED database to perform a review of the literature on the MMA to increase our understanding of its role in neurosurgery. After performing this review, we found that the MMA was commonly used to access DAVFs and meningiomas. Pseudoaneurysms and true aneurysms in the MMA can be effectively treated via endovascular or surgical removal. In MMD, the MMA plays a very important role in the development of collateral circulation and indirect revascularization. For recurrent CDSHs, after burr hole irrigation and drainage have failed, MMA embolization may be attempted. The MMA can also contribute to the occurrence and treatment of migraines. Because the ophthalmic artery can ectopically originate from the MMA, caution must be taken to avoid causing damage to the MMA during operations.

Dural Arteriovenous Fistula Between the Inferolateral Trunk and Cavernous Sinus Draining to Ophthalmic Vein

BACKGROUND Formation of a dural arteriovenous fistula (DAVF) between the inferolateral trunk (ILT) and cavernous sinus (CS) is rare. CASE DESCRIPTION This study presents a case of ILT-CS DAVF. A 64-year-old male patient had exophthalmos of the left eye with redness and swelling. Digital subtraction angiography revealed a connection between the ILT and the CS that formed a high-flow DAVF, which was drained only to the ophthalmic vein and no other parts of the CS. The ILT was chosen as the transarterial path for treatment because it was enlarged. The microcatheter was navigated into the ILT, and 2 coils were then used to occlude the ILT. After occlusion of the ILT, no image of the DAVF indicated that the ILT-CS DAVF was completely cured. The patients symptoms improved gradually after surgery. At the 6-month follow-up visit, digital subtraction angiography showed no sign of ILT-CS DAVF and the patients eye symptoms had disappeared. CONCLUSIONS Although ILT-CS DAVF is rare, it can still be seen in clinical practice. Coiling the ILT via a transarterial approach is a good option for treatment.

Delayed Establishment of Collateral Circulation from Posterior Meningeal Artery After Proximal Occlusion of Posterior Inferior Cerebellar Artery: Case Report and Literature Review

BACKGROUND A dissecting aneurysm on the posterior inferior cerebellar artery (PICA) is a rare entity, and endovascular embolization is often adopted. During the procedure, if the parent artery is occluded, the distal PICA is usually supplied by the ipsilateral anterior inferior artery or contralateral PICA. In extremely rare circumstances, the distal PICA can establish collateral circulation by transdural anastomosis with the posterior meningeal artery (PMA). CASE DESCRIPTION A 29-year-old woman was admitted complaining of thunderclap headache, nausea, and vomiting for 3 hours. Head computed tomography and digital subtraction angiography revealed subarachnoid hemorrhage and a dissecting aneurysm located at the tonsillomedullary segment of PICA. The parent artery distal to the aneurysm had no collateral circulation from the adjacent arteries. Selective endovascular coiling of the aneurysm with preservation of the parent artery was adopted for treatment. The patient experienced an uneventful postprocedural recovery. To our surprise, follow-up digital subtraction angiography 6 months later revealed complete occlusion of the aneurysm and parent artery at the site of aneurysm formation. A rare anastomosis between the distal PICA and PMA was established. CONCLUSIONS A report about this rare condition suggested that after occlusion of the PICA trunk, the distal PICA can form collateral circulation with the PMA. A potential collateral circulation may be present in advance between the PICA and PMA. When ischemia occurs in the distal PICA, this collateral circulation may open and could be reconstructed and enlarged to provide blood supply.

Acute rerupture after coil embolization of ruptured intracranial saccular aneurysms: A literature review:

Acute rerupture after coil embolization is defined as rerupture within three days after treatment; its prognosis is worse than that of rebleeding at other time periods. However, to date, little is known about complications during the acute phase. Therefore, we used the PubMed database to perform a review of acute rerupture after coil embolization of ruptured intracranial saccular aneurysms and increase our understanding. After reviewing the complications, we found that the cause of acute rerupture is unclear, but the following risk factors are involved: incomplete occlusion of the initial aneurysm, the presence of a hematoma adjacent to a ruptured aneurysm, an aneurysmal outpouching, poor Hunt-Hess grade at the time of treatment, and the location of the aneurysm in an anterior communicating artery. In addition, intraoperative rupture is a non-negligible cause. Acute rerupture after coil embolization mainly occurs within the first 24 hours after the procedure. Brain computed tomography is the gold standard for diagnosing acute rebleeding of a coiled aneurysm. For acute rerupture after coil embolization, prevention is critical, and complete occlusion of the aneurysm in the first session is the best protection against acute rebleeding. In addition, a restricted postembolization anticoagulation strategy is recommended for patients with high-risk aneurysms. For patients with an adjacent hematoma, surgical clipping is recommended. Most patients present no changes immediately after acute rebleeding because of their poor condition. However, surgical or endovascular treatments can be attempted if the patient is in an acceptable condition. Even so, the outcomes are typically unsatisfactory.

The Impact of Variational Primary Collaterals on Cerebral Autoregulation

The influence of the anterior and posterior communicating artery (ACoA and PCoA) on dynamic cerebral autoregulation (dCA) is largely unknown. In this study, we aimed to test whether substantial differences in collateral anatomy were associated with differences in dCA in two common types of stenosis according to digital subtraction angiography (DSA): either isolated basal artery and/or bilateral vertebral arteries severe stenosis/occlusion (group 1; group 1A: with bilateral PCoAs; and group 1B: without bilateral PCoAs), or isolated unilateral internal carotid artery severe stenosis/occlusion (group 2; group 2A: without ACoA and with PCoA; group 2B: with ACoA and without PCoAs; and group 2C: without both ACoA and PCoA). The dCA was calculated by transfer function analysis (a mathematical model), and was evaluated in middle cerebral artery (MCA) and/or posterior cerebral artery (PCA). Of a total of 231 non-acute phase ischemic stroke patients who received both dCA assessment and DSA in our lab between 2014 and 2017, 51 patients met inclusion criteria based on the presence or absence of ACoA or PCoA, including 21 patients in the group 1, and 30 patients in the group 2. There were no significant differences in gender, age, and mean blood pressure between group 1A and group 1B, and among group 2A, group 2B, and group 2C. In group 1, the PCA phase difference values (autoregulatory parameter) were significantly higher in the subgroup with patent PCoAs, compared to those without. In group 2, the MCA phase difference values were higher in the subgroup with patent ACoA, compared to those without. This pilot study found that the cross-flow of the ACoA/PCoA to the affected area compensates for compromised dCA in the affected area, which suggests an important role of the ACoA/PCoA in stabilizing cerebral blood flow.

Hybrid surgery for an arteriovenous malformation fed by an accessory middle cerebral artery and drained by a developmental venous anomaly: A case report and literature review

An accessory middle cerebral artery (AMCA), which mainly acts in the collateral circulation of the middle cerebral artery (MCA), is a rare anatomic malformation. Similar to other intracranial vessels, cerebrovascular disease can occur in the AMCA. However, the development of an arteriovenous malformation (AVM) in the AMCA is very rare, especially in conjuction with developmental venous anomalies (DVAs). Here, a rare case of an AMCA combined with an AVM and a DVA was reported. The patient was a 47-year-old female with intracranial hemorrhage at symptom onset. CT and MRI showed lesions in the left Sylvian fissure and insula accompanied by hemorrhage. DSA suggested a left AMCA; an AVM of the AMCA was located in the deep Sylvian fissure. The AVM was diffusely developed and drained into the DVA. The operation was performed in a hybrid operating room. The major feeding artery of the AVM, which was derived from the AMCA, was clipped, then the AVM and DVA were subsequently removed. Intraoperative DSA showed that the AVM and DVA were radically removed. A pathological examination confirmed the presence of an AVM. The patient recovered well and was discharged. Therefore, as highlighted in this case report, rare AVMs can be found in AMCAs and can even occur simultaneously with a DVA. Hybrid surgical treatment can be used to remove AVMs and can lead to an improved prognosis.

Carotid endarterectomy for in-stent restenosis: a case report and literature review

It is relatively difficult to treat restenosis when restenosis occurs following carotid artery stenting. Endarterectomy with simultaneous stent removal is an effective approach when restenosis occurs. The treatment method is still not well known. The present paper reports a case of restenosis after stenting that was treated with endarterectomy with a satisfactory treatment outcome. The patient, a 74-year-old male, underwent stenting 10 months before he was re-hospitalized. He seemed to recover well after stenting until one month before he was re-hospitalized, when he presented symptoms of cerebral ischemia. Imaging examination revealed that in-stent stenosis had reoccurred, with the stenosis degree ranging from 70–99%. He was given endarterectomy treatment, and intra-operative findings showed that the stent grew into a carotid artery plaque and protruded below the adventitia and that the stent lumen was not covered by carotid artery intima. The surgery completely and successfully removed the plaque and the stent, while the adventitia was completely preserved. Follow-up indicated that there was no stenosis in the carotid artery, and the prognosis was good. Relevant literature was also reviewed in this paper, and the authors suggested that carotid artery plaque and stent endarterectomy is beneficial. However, surgical treatment for in-stent stenosis remains a challenging option.