Anatomical features of the occipital artery on CTA and differences between patients with/without stenosis and occlusion of the internal carotid artery.

The understanding of the basic anatomy of the occipital artery (OA) is crucial, and computed tomography angiography is an effective tool for this purpose. In the present study, a comparison between healthy subjects and patients with internal carotid artery (ICA) stenosis and occlusion was made. The following parameters were measured: Age, sex, diameters and lengths of the OA in different locations, distance from the edge of the foramen magnum to the OA and the distance from the midline to the OA at the level of the superior nuchal line. A total of 205 participants who met the inclusion criteria were selected for further investigation. In addition, 50 healthy subjects (100 sides, left and/or right) were selected as the control group. A total of 155 patients (180 sides, left and/or right) were selected as the stenosis and occlusion groups, including the mild and moderate ICA stenosis group (50 sides, left and/or right), severe ICA stenosis group (80 sides, left and/or right) and the ICA occlusion group (50 sides, left and right). General information, measured parameters and statistical analysis results are provided for these groups. No significant differences were observed in the anatomical parameters of the OA among these groups. Thus, in addition to providing anatomical data, the present study demonstrates that stenosis and the occlusion of the ICA do not significantly alter the anatomy of the OA.

Parent artery occlusion for flow-related aneurysms at the proximal segment of the main feeding arteries of cerebellar arteriovenous malformations.

BACKGROUND: Flow-related aneurysms (FRAs) associated with cerebellar arteriovenous malformations (AVMs) are complicated, and their management is difficult. We performed a retrospective study to explore the efficacy and outcome of parent artery occlusion (PAO) for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs. MATERIALS AND METHODS: A retrospective study was performed for patients admitted for a cerebellar AVM between January 2015 and December 2019. Patients were included if (a) they presented with a ruptured or symptomatic FRA at the proximal segment of the main feeding arteries of the cerebellar AVM, (b) the cerebellar AVM did not bleed before admission, (c) the FRA was secured via PAO of the parent feeding artery, and (d) the cerebellar AVM was not intentionally managed or embolized through other feeding arteries during hospitalization. RESULTS: Eight patients aged between 27 and 72 (48.6 ± 14.3) years were identified. Eight ruptured and symptomatic FRAs at the proximal segment of the main feeding arteries of the cerebellar AVMs underwent PAO with coils or Onyx while preserving the arteries distal to the aneurysms. All the patients achieved a favorable recovery after treatment in a follow-up ranged from 8 to 48 months. One patient experienced FRA recurrence and underwent a second PAO. CONCLUSIONS: PAO for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs is a feasible option. This method is effective in preventing re-rupture of the FRAs and relieving the symptoms in the short term, allowing sufficient time for the patients to receive subsequent treatment.

CT angiographic study of the cerebral deep veins around the vein of Galen.

Research on the anatomy of cerebral deep veins (CDVs) around the vein of Galen (VG) is very important and has fundamental clinical significance. Large-scale anatomical studies of CDVs using computed tomography angiography (CTA) are rarely reported. A retrospective study of the CDVs around the VG was conducted in Chinese patients of Han nationality. One hundred cases were included in the final analysis. The patients were aged from 17 to 78 years (mean: 42.3 years). Also, 46% of the patients were female. The diameter of the internal cerebral vein (ICV) at its beginning and termination points ranged from 0.4 to 2.8 mm (1.49 ± 0.39 mm) and 0.4 to 3.5 mm (2.05 ± 0.47 mm), respectively. There was statistical significance regarding the diameter of the ICV at its beginning and termination points (P <0.01). The ICV length ranged from 28.5 to 47.9 mm (36.86 ± 3.74 mm). The length of the straight sinus (SS) ranged from 30.2 to 57.8 mm (43.6 ± 6.37 mm). The length of the VG ranged from 1.5 to 41.8 mm (9.30 ± 4.76 mm). The angle at the VG and SS transition area ranged from 25.4 to 110.6° (77.2 ± 18.0°). This study was a meaningful attempt to conduct anatomical research of CDVs using CTA. Preoperative familiarity with the normal venous structure and its variation around the VG would be helpful for endovascular treatment.

The prospects and pitfalls in the endovascular treatment of moyamoya disease-associated intracranial aneurysms.

Moyamoya disease (MMD) is characterized by progressive stenosis or occlusion of the distal internal carotid artery and simultaneous formation of collateral vasculature. The fragile alteration and increased hemodynamic stress in the intra- and extracranial vasculature would conjointly result in the formation of intracranial aneurysms in MMD patients. According to our classification, the MMD-associated aneurysms are divided into the major artery aneurysms (MAAs) and non-MAAs. The non-MAAs are further subdivided into the distal choroidal artery aneurysms, moyamoya vessel aneurysms, transdural collateral aneurysms, and anastomosis aneurysms. Currently, endovascular treatment (EVT) has become the main stream for the MMD-associated aneurysms. There is no difference to EVT for the MMD-associated MAAs of the non-stenosed major arteries with that in the non-MMD patients. While it is a big challenge to perform EVT for MMD-associated aneurysms in the stenosed arteries. Generally speaking, the parent arteries of the non-MAAs are slim, and super-selective catheterization is technically difficult. Most of the times, parent artery occlusion with liquid embolic agents or coils can only be performed. The vasculature in MMD patients is fragile; perioperative management and meticulous intraoperative manipulation are also very important to avoid complications during EVT. In spites of the complications, the EVT can bring good outcome in selected cases of MMD-associated aneurysms.

Intracranial post-clipping residual or recurrent aneurysms: Current status and treatment options (Review).

Following the clipping of intracranial aneurysms, post-clipping residual or recurrent aneurysms (PCRRAs) can occur. In recent years, the incidence of PCRRAs has increased due to a prolonged follow-up period and advanced imaging techniques. However, several aspects of intracranial PCRRAs remain unclear. Therefore, the present study performed an in-depth review of the literature on PCRRAs. Herein, a summary of PCRRAs that can be divided into the following two categories is presented: i) Those occurring after the incomplete clipping of an aneurysm, where the residual aneurysm regrows into a PCRRA; and ii) those occurring after the complete clipping of an aneurysm, in which a de novo aneurysm occurs at the original aneurysm site. Currently, digital subtracted angiography remains the gold standard for the imaging diagnosis of PCRRAs as it can eliminate metallic clip artifacts. Intracranial symptomatic PCRRAs should be actively treated, particularly those that have ruptured. A number of methods are currently available for the treatment of intracranial PCRRAs; these mainly include re-clipping, endovascular treatment (EVT) and bypass surgery. Currently, re-clipping remains the most effective method used to treat PCRRAs; however, it is a very difficult procedure to perform. EVT can also be used to treat intracranial PCRRAs. EVT methods include coiling (stent- or balloon-assisted) and flow-diverting stents (or coiling-assisted). Bypass surgery can be selected for difficult-to-treat, complex PCRRAs. On the whole, following appropriate treatment, the majority of intracranial PCRRAs achieve a high occlusion rate and a good prognosis.

Imaging characteristics and endovascular treatment strategy for cerebellar arteriovenous malformations.

Cerebellar arteriovenous malformations (CAVMs) have increased probabilities of rupture and bleeding compared with arteriovenous malformations (AVMs) in other locations of the brain. Endovascular treatment (EVT) for CAVMs is difficult; as the angioarchitecture of CAVMs is complex, EVT may be associated with complications, due to the involvement of crucial structures, such as the brainstem. The present study aimed to determine the efficacy of EVT for CAVMS. For this purpose, 33 cases of CAVMs treated with EVT from January, 2015 to January, 2020 were retrospectively analyzed. The 33 patients were aged 8 to 73 years (mean age, 40.4±17.8 years) and 21 were female (63%, 21/33). Rupture and bleeding occurred in 29 patients (87.9%, 29/33). Among the 33 CAVM cases, 15 (45.5%, 15/33) were fed by a single artery, and 18 (54.5%, 18/33) were fed by multiple arteries. In total, 27 patients (81.8%, 27/33) had superficial vein drainage alone. Among the 33 cases, 15 were complicated by 16 aneurysms, including 14 prenidal aneurysms and 2 intranidal aneurysms. Among the 33 cases, the nidus of the CAVM (87.9%, 29/33) was treated with Onyx™ casting in 29 patients: 8 cases (27.6%, 8/29) had an embolization volume of <1/3 of the nidus, 11 cases had a volume of 1/3-2/3 of the nidus (37.9%, 11/29) and 10 cases had a volume >2/3 of the nidus (34.5%, 10/29). Among the EVT complications, there were 3 cases (9.1%, 3/33) of intraoperative and post-operative bleeding, which resulted in two deaths (on the 1st and 7th days). The length of hospital stay was 10.7±5.4 days. In total, 27 patients (81.7%, 27/33) had a Glasgow Outcome Scale (GOS) score of 5 at discharge. On the whole, the present study demonstrates that overall, EVT is a feasible treatment for CAVM and may be used to obtain acceptable therapeutic effects.

Endovascular treatment of the cavernous sinus dural arteriovenous fistula: current status and considerations.

A cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication involving the dura mater within or near the CS wall. The dural arteries from the internal carotid artery and external carotid artery supply the CS-DAVF, and the superior ophthalmic vein (SOV) and inferior petrous sinus (IPS) are frequent venous drainers. In CS-DAVF cases, high-risk lesions require treatment. Endovascular treatment (EVT) has been the first-line option for CS-DAVFs. To our knowledge, a review of the EVT of CS-DAVFs is lacking. Therefore, in this paper, we review the available literature on this issue. In addition, some illustrative cases are also provided to more concisely expound the EVT of CS-DAVFs. According to the recent literature, transvenous embolization via the IPS is considered the most effective method for EVT of CS-DAVFs. In addition, the transorbital approach is another reasonable choice. Other venous approaches can also be tried. Because of the low cure rate, transarterial embolization for CS-DAVFs is limited to only highly selected patients. In the EVT of CS-DAVFs, various agents have been used, including coil, Onyx, and n-butyl cyanoacrylate, with coil being the preferred one. In addition, when EVT cannot obliterate the CS-DAVF, stereotactic radiotherapy may be considered. In general, despite various complications, EVT is a feasible and effective method to manage CS-DAVFs by way of various access routes and can yield a good prognosis.

Acute hydrocephalus secondary to traumatic perimesencephalic pneumocephalus: A case report.

INTRODUCTION: Acute hydrocephalus is a common complication of spontaneous or traumatic intracranial bleeding with extensive subarachnoid hemorrhage (SAH) or ventricular extension. However, it has never been reported to be secondary to pneumocephalus. PATIENT CONCERNS: A 32-year-old man was admitted following a motorcycle accident. Head computed tomography (CT) performed right after the accident revealed a skull base fracture and mild perimesencephalic SAH. Three days later, repeated CT revealed delayed perimesencephalic pneumocephalus and an evident enlargement of the ventricular system. DIAGNOSIS: The patient was diagnosed with acute obstructive hydrocephalus, which was secondary to pneumocephalus and traumatic SAH. INTERVENTIONS: The patient was treated with temporary external ventricular drainage (EVD). OUTCOMES: The patient experienced an unremarkable recovery process. At follow-up 3 months later, he showed no recurrence of the hydrocephalus and the score of Glasgow Outcome Scale was 5. CONCLUSION: Transient mechanical obstruction of CSF circulation and disturbance of CSF physiology might conjointly lead to the acute obstructive hydrocephalus.

Anatomical Study of Anterior Inferior Cerebellar Artery and Its Reciprocal Relationship with Posterior Inferior Cerebellar Artery Based on Angiographic Data.

BACKGROUND: Anterior inferior cerebellar artery (AICA) can present with a myriad of variations. However, the previous studies of AICA anatomy were based on small-scale cadaveric investigation. In this study, we performed an angiographic study of AICA in 500 Chinese with Han nationality based on digital subtraction angiography (DSA). METHODS: Patients admitted to our institution between 2015 and 2018 who had underwent DSA were potential candidates for this retrospective evaluation. The exclusion criteria were: a) patients with vascular diseases of the posterior circulation; b) ischemic diseases or moyamoya disease of the anterior circulation. RESULTS: Five hundred patients were identified. The patients ranged in age from 6 to 75 years. Two hundred thirty-seven (62.9%, 237 of 377) patients had bilateral AICAs at the same level, and 140 (37.1%, 140 of 377) had bilateral AICAs at different levels. The developing states of AICA were grade 0 in 31 (3.5%, 31 of 896), grade 1 in 373 (41.6%, 373 of 896), grade 2 in 313 (34.9%, 313 of 896), and grade 3 in 179 (20.0%, 179 of 896) hemispheres. Two hundred twenty-one (22.1%, 221 of 1000) presented with AICA-PICA common trunks. Thirty-one (3.1%, 31 of 1000) hemispheres showed no obvious AICA angiographically. AICA arose as a single trunk in 865 (86.5%, 865 of 1000) hemispheres, and as duplicate trunks in 104 (10.4%, 10 of 1000) hemispheres. Triplicate or more trunks were not seen. AICA originating from the basilar artery fenestration accounted for 4% (20 of 500) of the cases. CONCLUSIONS: This is the first attempt using DSA data to perform a large-scale investigation of AICA variations. The ever-growing need of endovascular intervention calls for more suitable anatomical explanation of the vascular structures.