The Occipital Artery as an Alternative Donor for Low-Flow Bypass to Anterior Circulation After Internal Carotid Artery Occlusion Failure prior to Exenteration for an Atypical Cavernous Sinus Meningioma

Occipital artery bypass importance in unsuitable superficial temporal artery: Two case reports

BACKGROUND

Superficial temporal artery-middle cerebral artery (STA-MCA) bypass helps treat cerebral ischemia. However, the STA is not available for bypass in some conditions. Therefore, with some technical tips, the authors introduced a bypass technique using the occipital artery (OA).

CASE SUMMARY

Two female patients complained of hemiparesis. Brain magnetic resonance imaging (MRI) indicated contralateral infarction from the MCA steno-occlusion. On Diamox single photon emission computed tomography or perfusion MRI, the contralateral front parietotemporal reserve was diminished. On transfemoral cerebral angiography, the STA was thin with a weak flow; however, the OA was prominent. Direct OA-MCA end-to-side extracranial-intracranial bypass surgery was implemented instead of STA because the caliber was too narrow. The postoperative course was uneventful in both cases, with well-maintained bypass patency and neurological stability during follow-up.

CONCLUSION

OA might be an acceptable alternative for MCA cerebral ischemic cases with an unsuitable STA.

Giant Aneurysm Management

The treatment of giant aneurysms has always been a challenge in the field of neurovascular disease. Giant aneurysms are larger in size and are associated with thrombosis development and the calcification of the aneurysmal wall and neck, which often interfere with direct clipping. Most giant aneurysms have a wide neck with an incomplete thrombus, making complete embolization almost impossible. Giant aneurysms of different sites have entirely different hemodynamic characteristics. Moreover, aneurysms at the same site may exhibit very different hemodynamics among different individuals. Therefore, careful assessment of each case is required before and during treatment to develop and carry out an individualized treatment plan.

Clinical importance of the occipital artery in vascular lesions: A review of the literature

The occipital artery (OA) is a critical artery in vascular lesions. However, a comprehensive review of the importance of the OA is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the OA to increase our understanding of its role in vascular lesions. We also provided our typical cases to illustrate the importance of the OA. The OA has several variations. For example, it may arise from the internal carotid artery or anastomose with the vertebral artery. Therefore, the OA may provide a crucial collateral vascular supply source and should be preserved in these cases. The OA is a good donor artery. Consequently, it is used in extra- to intracranial bypasses for moyamoya disease (MMD) or aneurysms. The OA can be involved in dural arteriovenous fistula (DAVF) and is a feasible artery for the embolisation of DAVF. True aneurysms and pseudoaneurysms can occur in the OA; surgical resection and embolisation are the effective treatment approaches. Direct high-flow AVF can occur in the OA; embolisation treatment is a good option in such cases. The OA can also be involved in MMD and brain arteriovenous malformation (AVM) by forming transdural collaterals. For a patient in the prone position, if occipital and suboccipital craniotomies are performed, the OA can also be used for intraoperative angiography. In brief, the OA is a very important artery in vascular lesions.

Occipital artery-anterior cerebral artery bypass with posterior auricular artery-middle cerebral artery bypass for stenosis of the internal carotid artery bifurcation

Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, and STA-anterior cerebral artery (ACA) bypass, are options for direct revascularisation of anterior circulation. However, some patients don't have a suitable STA to use as a donor, so an alternative procedure must be performed. A 59-year-old, right-handed man presented with dysphasia and right-sided hemiparesis due to a transient ischaemic attack. Imaging studies revealed severe stenosis of the left internal carotid artery bifurcation. Iodoamphetamine single photon emission computed tomography demonstrated reduced cerebrovascular reserve capacity in the left hemisphere. The patient was started on antiplatelet therapy, but the ischaemic attacks persisted after one month. Thus, revascularisation of the ACA and MCA territories was considered. Digital subtraction angiography revealed prominence in the left occipital artery (OA) and posterior auricular artery (PAA), while the left STA was hypoplastic, terminating at the squamous suture level. Therefore, anastomoses were performed between both the OA and ACA and the PAA and MCA. Revascularisation was successful, and the ischaemic attacks disappeared. OA-ACA bypass, together with PAA-MCA bypass, may be effective for wide cerebral revascularisation when the STA is not available.

Extracranial-intracranial bypass in medial sphenoid ridge meningioma associated with severe stenosis of the intracranial segments of the internal carotid artery: A case report

RATIONALE

Tumor resection and extracranial-intracranial bypass concerning medial sphenoid ridge meningioma associated with severe stenosis of the internal carotid artery (ICA) of intracranial segments has been rarely presented. Effective treatment as to the complex lesions may be complicated. Tumor resection and cerebrovascular protection should be both taken into consideration.

PATIENT CONCERNS

We presented one case of medial sphenoid ridge meningioma associated with severe stenosis of the internal carotid artery of intracranial segments. The patient suffered hyperthyroidism, mirror-image dextrocardia and congenital heart disease atrial septal defect simultaneously.

DIAGNOSES

Before the neurosurgical treatment , the colleagues of department of cardiac surgery, anesthesiology and respiratory medicine agreed on our plan of resecting the tumor following the comprehensive evaluation of basal clinical conditions in the patient. For reducing the bleeding intraoperatively, the interventional branch performed digital subtraction angiography(DSA) and found collateral anastomosis between the supplying vessels of left middle meningeal arteries and anterior choroid arteries. No preoperative interventional embolization was determined considering the risk of cerebral ischemia.

INTERVENTIONS

The following subtotal resection of medial sphenoid ridge meningioma and left extracranial-intracranial bypass were carried out. Additionally, ipsilateral decompressive craniectomy was done. Post-operative imaging Computed tomography (CT), Computed tomography angiography (CTA) and Transcranial Doppler (TCD) indicated subtotal resection of tumor and bypass patency.

OUTCOMES

The patient was discharged with the right limbs of muscle strength of grade IV. The muscle strength of the patient returned to grade V after 6 months of follow-up.

LESSONS

Comprehensive treatment of tumor resection and extracranial-intracranial bypass concerning medial sphenoid ridge meningioma associated with severe stenosis of the internal carotid artery of intracranial segments is effective.