Efficacy of arterial spin labeling for detection of the ruptured micro-arteriovenous malformation: illustrative cases.

BACKGROUND: Diagnosis of a microarteriovenous malformation (micro-AVM) is difficult, especially in the acute stage of rupture because of the small size of the nidus and the existence of hematoma. We report two cases of ruptured micro-AVMs detected by arterial spin labeling (ASL). OBSERVATIONS: In one case, a 45-year-old male was transported with a complaint of right hemiparesis. Computed tomography (CT) revealed a right parietal lobar hemorrhage. Standard magnetic resonance imaging (MRI) showed no abnormal findings as the cause of the hemorrhage. ASL 23 days after the onset demonstrated high signals on the medial wall of the hematoma. Digital subtraction angiography (DSA) showed a micro-AVM in accordance with the site of high signals on ASL. In another case, a 38-year-old female was transported with a complaint of left hemianopsia. CT on admission revealed a right parietal lobar hemorrhage. Standard MRI showed no abnormal findings as the cause of the hemorrhage. ASL 15 days after the onset demonstrated high signals on the internal wall of the hematoma. DSA showed micro-AVM in accordance with the site of high signaling on ASL. Both cases were successfully treated with open surgery. LESSONS: ASL can manifest micro-AVMs as high signals within the hematoma. ASL is a useful less-invasive screening tool for the detection of ruptured micro-AVMs.

[How to Avoid Intraoperative Rupture and What to Do When It Ruptures].

Intracranial aneurysm rupture is the main fatal complication of coil embolization for an intracranial aneurysm performed in conjunction with systemic heparinization. We answered five clinical questions about anesthesia, systemic heparinization, intraoperative aneurysmal rupture, the balloon-assisted technique, and the next step of initial response in case of aneurysmal rupture. It is crucial to understand when and why intraoperative aneurysmal rupture occurs to reduce its mortality rate. In cases of intraoperative problems, never pull the microcatheter or coil when perforating an aneurysm; lowering blood pressure, administering protamine for the reversal of heparin, and occluding blood flow into an aneurysm by inflating balloon(s) will help in the treatment. It is our pleasure that this chapter will help in your daily care.

Optimal Timing of Extracranial-Intracranial Bypass with Microsurgical Trapping for Ruptured Blister Aneurysms of the Internal Carotid Artery.

OBJECTIVE: Ruptured blister aneurysms of the internal carotid artery are challenging to treat because of their difficult diagnosis and the fragility of the wall structure. Here, we sought to clarify the efficacy of extracranial-intracranial bypass followed by trapping (bypass/trapping) for ruptured blister aneurysms. METHODS: A retrospective study identified 45 patients with ruptured blister aneurysms between 1998 and 2017. Our principle was to attempt bypass/trapping as early as possible after diagnosis (early surgery). If early diagnosis was difficult, patients underwent elective surgery in the later stage when aneurysms were detected (elective surgery). Patient characteristics, radiologic findings, clinical course, and outcomes were analyzed. RESULTS: Forty-three patients were treated by bypass/trapping. Twenty-eight patients were classified as early surgery and 15 as elective surgery. Two patients experienced fatal rebleeding and did not undergo surgery. All 15 patients in the elective surgery group showed rebleeding and/or aneurysmal growth while awaiting surgery. In the elective surgery group, 10 aneurysms were missed initially by catheter angiography. In the early surgery group, 9 patients were assessed by vessel wall magnetic resonance imaging, which showed circumferential enhancement along the aneurysm wall, most of which was shown as only a small bulge in the angiography. Postoperative rebleeding did not occur in any of the patients. CONCLUSIONS: Bypass/trapping is effective to prevent rebleeding. Early surgery may be beneficial, because most patients in the elective surgery group showed rebleeding or aneurysmal growth. Vessel wall magnetic resonance imaging is a useful adjunct for early diagnosis and may contribute to prompt early surgery.

Preoperative embolization and immediate removal of a giant pituitary adenoma: a case report.

BACKGROUND: Giant pituitary adenomas, with maximum diameter of at least 40 mm, continue to involve high surgical risks despite recent advances in microsurgical and/or endoscopic surgery. We treated a case of giant pituitary adenoma with preoperative endovascular embolization in an attempt to reduce blood loss. CASE PRESENTATION: A 48-year-old Japanese Woman presented with severe right visual disturbance. Magnetic resonance imaging revealed a giant pituitary adenoma with maximum diameter of 82 mm. Angiography revealed significant tumor stain, with blood supply mainly from the branches of the right meningohypophyseal trunk. These feeding arteries were endovascularly embolized with n-butyl cyanoacrylate. Subsequently, the tumor was safely removed by transsphenoidal surgery in two stages. The patient showed significant improvement of visual disturbance postoperatively, and was discharged without other neurological deficit. The surgical policy was explained preoperatively to the patients and written informed consents were obtained. CONCLUSIONS: Preoperative embolization of a giant pituitary adenoma is a useful procedure that can potentially decrease the morbidity and mortality of this devastating tumor.

Usefulness of laser speckle flowgraphy for the assessment of ocular blood flow in extracranial-intracranial bypass.

Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus. The authors present a case of symptomatic internal carotid artery occlusion treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in which an improvement of ocular circulation was confirmed by LSFG. A 47-year-old man presented with a 1-month history of repeated left blurred vision and motor weakness of the right leg. Diffusion-weighted magnetic resonance imaging revealed a small infarction in the left frontal lobe. Carotid angiography revealed that the left internal carotid artery was occluded at the C4 portion. Single-photon emission computed tomography indicated that the cerebral blood flow in the left MCA territory was markedly impaired. Ophthalmologic examination revealed ischemic change of the left optic fundi, and LSFG revealed decreased blood flow around the left optic disc. Left STA-MCA bypass was successfully performed. Both ischemic ocular symptoms and the ischemic symptoms of the right leg were completely recovered after surgery. Postoperative ophthalmologic examination revealed improvement of both ischemic changes of the left optic fundi. Moreover, LSFG revealed improvement of the blood flow around the left optic disc. LSFG can be a promising clinical tool for the assessment of ocular circulation before and after bypass surgery for occlusive cerebrovascular disease.

[Flow dynamics analysis in patients with a ruptured middle cerebral artery aneurysm. A case report].

Despite advancement of diagnostic and treatment modalities, subarachnoid hemorrhage (SAH) is still an entity of neurosurgical emergency with poor outcome. Recent reports indicated that hemodynamic stress might play an important role in rupture or the growth of cerebral aneurysms, but there is no consensus about how or which hemodynamic factor contribute to this phenomenon. In this report, magnetic resonance (MR)-based flow dynamics analysis was performed for a patient with SAH and the data obtained were directly compared with intraoperative findings. This 74-year-old woman was admitted for sudden onset headache. Head computed tomography scan showed SAH on the right sylvian fissure and intracerebral hematoma on the right temporal tip. Digital subtraction angiography showed a right middle cerebral artery aneurysm, which was considered to be the ruptured one. The aneurysm had two blebs, and the bleb around the aneurysm tip was exposed to low magnitude and high oscillation of wall shear stress (WSS). On the other hand, another bleb was exposed to high magnitude and low oscillation of WSS. Next day, the patient underwent open surgery and intraoperative findings showed the aneurysm tip was the ruptured point. MR-based flow dynamics analysis might be a useful diagnostic modality for patients with SAH. Although low magnitude and high oscillation of WSS might contribute to the aneurysm rupture, further case accumulation is necessary to reach a conclusion whether or not this is so.

De novo formation of orbital cavernous malformation 9 years after surgical management of dural arteriovenous fistula in the anterior middle fossa: case report.

A 30-year-old man presented with recurrent dural arteriovenous fistula (dAVF) associated with de novo orbital cavernous malformation (CM), manifesting as progressive left visual disturbance. He had undergone transarterial embolization and subsequent surgical management for a left anterior middle fossa dAVF 9 years previously. External carotid angiography showed recurrence of the dAVF. Magnetic resonance imaging revealed a well delineated intraorbital mass lesion with hypointense signal rim by T(2)-weighted imaging, adjacent to the shunting point of the recurrent dAVF. Transcranial subtotal removal of the intraorbital mass lesion through the orbitopterional approach revealed continuity between the mass lesion and the draining vein of the recurrent dAVF. The histological diagnosis was CM. His symptom was relieved postoperatively, and no regrowth was seen during the follow-up period of one year. The coexistence of recurrent dAVF with newly formed orbital CM is extremely rare, but may indicate the underlying mechanism of the formation of CMs and recurrent dAVF.

Melanotic neuroectodermal tumor of the brain recurring 12 years after complete remission: case report.

We describe a rare case of melanotic neuroectodermal tumor (MNT) of the brain recurring 12 years after complete remission. An 11-year-old girl initially presented with exotropia and bilateral papilledema. Magnetic resonance (MR) imaging revealed an intracranial extraaxial large tumor at the midfrontal region. T(1)-weighted MR imaging showed the tumor to be well delineated with homogeneous enhancement by gadolinium. The tumor was subtotally removed, and the histological diagnosis was MNT. The residual tumor became enlarged, so gamma knife radiosurgery was performed 5 months after initial surgery. The enhanced lesion disappeared, but another lesion emerged 3 years later. A second gamma knife radiosurgery was performed for this local recurrence. The enhanced lesion disappeared once again. Twelve years after the second gamma knife radiosurgery, another local recurrence was detected. This tumor was subtotally removed. Histological examination confirmed the same diagnosis of MNT. This case suggests that MNTs not completely resected need long-term follow up, even if complete remission was achieved after adjuvant therapy.