Bypass-Assisted Microsurgical Clipping for an Endovascular Treatment-Resistant Ruptured Internal Carotid-Posterior Communicating Artery Aneurysm, Recurring Two Decades Postinitial Clipping: 2-Dimensional Operative Video.

Salvage treatment of postclipping recurrent aneurysms remains challenging.1,2 The salvage microsurgical clipping is a possible intervention but sometimes difficult because of tissue adhesions around the aneurysm and previously installed clips; therefore, salvage coil embolization may have certain advantages.1-5 However, when coil embolization is not applicable,6 microsurgical clipping is a stand-alone curative treatment, requiring proficient and reliable microsurgical techniques. This article describes a unique case of a 70-year-old female patient complaining of a severe headache with subarachnoid hemorrhage due to a recurrent ruptured left internal carotid-posterior communicating artery aneurysm after microsurgical clipping 23 years ago. An initial attempt at coil embolization proved unsuccessful because of the aneurysm shape. Consequently, the salvage microsurgical clipping was planned. Given the additional time for trapping the internal carotid artery for the old clip removal, a superficial temporal artery-middle cerebral artery bypass was also planned. The operation entailed a superficial temporal artery-middle cerebral artery bypass, a Sylvian fissure dissection, the old clip removal, and aneurysm clipping. Intraoperatively, the complete aneurysm neck clipping was successfully performed without any complication, and patient postoperative course was uneventful. A wide surgical field should be obtained to be able to manipulate the aneurysm and old clip safely under a microscope. It is also important to temporarily trap the main artery to ensure removal of old clips and to prepare for intraprocedural ischemia using bypass after a precise assessment of hemodynamics before surgery. The patient provided informed consent for the procedure and the publication of the case along with its pertinent imaging, and this report was approved by the institutional review board at our hospital.

Orbital Arteriovenous Fistula Causing Only Visual Impairment due to Compression of the Optic Nerve by the Dilated Superior Ophthalmic Vein.

Orbital arteriovenous fistula (AVF) is a rare disease, and its standard therapeutic strategy has not been established. A 70-year-old male consulted an ophthalmologist due to a visual field defect in his left eye. Neurological findings showed visual impairment but no symptoms such as exophthalmos, conjunctival congestion, or diplopia. Magnetic resonance imaging showed marked dilation of the left superior ophthalmic vein (SOV). Cerebral angiography revealed an AVF that was limited to the left orbit. The feeder was a branch of the ophthalmic artery that originated from the first portion, and the drainer was the SOV, which was meandering and significantly dilated. Since the only symptom was visual impairment, the etiology was considered to be compression of the optic nerve due to a dilated SOV rather than increased venous pressure. Transvenous embolization via the facial vein was performed, and a visual field examination 1 week after the operation revealed marked improvement. Orbital AVF that develops only with visual impairment is extremely rare. As demonstrated with this case, coil embolization for proper position and reduction of the venous pressure, which relieves compression on the optic nerve, may be useful in improving the visual impairment.

Extradural Middle Fossa and Transcavernous Approach for Resection of Trigeminal Neurinoma at Lateral Cavernous Sinus.

We present a 52-year-old male case of right trigeminal neurinoma at lateral cavernous sinus. The tumor was 40 mm in maximum diameter, obviously compressed temporal lobe and encased internal carotid artery. Extradural middle fossa and transcavernous approach was applied and the tumor was resected via Parkinson's triangle. This approach enabled safe and effective tumor resection, sufficient visualization, and operative field ( Figs. 1 and 2 ). We performed dissection of the tumor from trigeminal nerve, tentorium, and middle fossa and resect the tumor around internal carotid artery sufficiently. Postoperative course was good without any new neurological deficit. This surgical method is considered safe and effective for the resection of the tumor at lateral cavernous sinus. The link to the video can be found at: https://youtu.be/2ekuILIgEuo.

STA-A3 Bypass Using Radial Artery Graft for Progressive Cerebral Infarction of Bilateral ACA Region after STA-MCA Bypass Surgery for Moyamoya Disease.

Direct revascularization surgery, such as superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, is effective in preventing ischemia and hemorrhage for moyamoya disease. On the other hand, when ischemia of the anterior cerebral artery (ACA) region progresses after ipsilateral STA-MCA bypass, it is difficult to perform revascularization from the viewpoint of the donor artery. A 55-year-old woman with right hemiparesis was diagnosed with cerebral infarction due to moyamoya disease. Left STA-MCA bypass was performed with no postoperative complications, but memory impairment and decreased motivation were observed 2 months after the operation. Magnetic resonance imaging and angiography revealed new infarction in the bilateral ACA area and deterioration in the signal intensity of bilateral ACAs. Revascularization of the bilateral ACA regions was considered necessary, but the left STA was already used in the previous surgery. Therefore, STA-radial artery (RA)-A3 bypass using RA graft combined with right STA-MCA bypass was performed. STA-A3 bypass using an RA graft may be the optimal treatment for ischemia of the ACA region that progresses after STA-MCA bypass.

Impact of Extracranial-Intracranial Bypass on Cognitive Function in a Patient with Chronic Cerebral Ischemia.

Extracranial-intracranial (EC-IC) arterial bypass surgery was developed to prevent subsequent stroke by improving hemodynamics distal to the occluded intracranial artery, but its utilization has been decreasing due to the development in medical treatment. However, EC-IC bypass surgery may be effective for arresting or reversing cognitive decline in patients with cerebral ischemia. A 69-year-old man with the left internal carotid artery occlusion that manifested as scattered cerebral infarction of the left hemisphere presented with dysarthria and transient right hemiparesis. Hemodynamic condition was impaired in the left side, and therefore, EC-IC bypass surgery was performed to prevent recurrence of cerebral infarction. Neuropsychological examination at 6 months after the surgery showed marked improvement as compared to the preoperative examination and there was no recurrence of stroke in the patient. EC-IC bypass may contribute to the improvement of cognitive function as well as the prevention of recurrence of cerebral infarction in patients with hemodynamic insufficiency, but there might be a threshold of hemodynamic impairment with respect to the reversibility of cognitive performance. Investigation of the target and timing can identify cases in which the cognitive function is improved by surgery.

T11/T12 ossification of the yellow ligament contributing to thoracic myelopathy in patient with posterior fossa arachnoid cyst and acquired incidental Chiari I malformation/syrinx.

BACKGROUND: Thoracic ossification of the yellow ligament (OYL) may contribute to myelopathy. In the case presented, the patient additionally had a chronic posterior fossa arachnoid cyst with an acquired Chiari I malformation and cervicothoracic syrinx. CASE DESCRIPTION: A 40-year-old female with a posterior fossa arachnoid cyst found 17 years ago, and newly acquired Chiari I malformation (tonsils down 5 mm) with a C7-T5 syrnix, presented with the new onset of lower extremity myelopathy. The MR documented marked dorsolateral cord compression due to T11/T12 OYL. Six months following a laminectomy for resection of OYL, the patient was asymptomatic. CONCLUSION: In patients presenting with the new onset of lower extremity myelopathy, evaluation of the complete neuraxis may be warranted. Here, the patient has an unchanged posterior fossa arachnoid cyst with an acquired Chiari I malformation/C7-T5 syrinx. However, the patient's symptoms were fully attributed to the MR-documented T11/T12 OYL that was successfully resected.

Emergent surgical embolectomy for middle cerebral artery occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm in the anterior communicating artery.

BACKGROUND: Intracranial embolism related to cerebral angiography is rare but one of the complications of the procedure. However, the standard management of acute intracranial embolism for this etiology has not been established, and there have been very few reports in the past. CASE DESCRIPTION: A 68-year-old male was incidentally found to have an unruptured aneurysm of anterior communicating artery (ACoA). Immediately after the cerebral angiography for the purpose of detailed examination of the aneurysm, the right partial hemiparalysis and mild aphasia developed. Magnetic resonance imaging/angiography (MRI/A) revealed an occlusion in the peripheral part of the left middle cerebral artery (MCA). Due to the existence of magnetic resonance angiography-diffusion mismatch, emergent craniotomy was immediately performed to remove intra-arterial thrombus. We also performed clipping for an unruptured ACoA aneurysm with this approach. Postoperative MRI/A showed that the occluded artery was recanalized and a slight infarction was observed in the left cerebral hemisphere. The patient was discharged on foot and followed at outpatient clinic over 4 years without no neurological deficit. CONCLUSION: Emergent surgical embolectomy for distal MCA occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm of the ACoA was successful in treating acute occlusion of the peripheral part of the MCA in a patient with an unruptured aneurysm. As there are few similar cases, there is controversy about the best management, but this surgical method can be a safe and effective treatment.

Superficial temporal artery-superior cerebellar artery bypass and proximal occlusion through anterior petrosal approach for subarachnoid hemorrhage due to basilar artery dissection.

BACKGROUND: Subarachnoid hemorrhage (SAH) due to rupture of basilar artery dissection (BAD) is extremely rare and often has a poor prognosis. Since ruptured BAD has high rate of rebleeding and mortality, treatment to prevent rerupture is mandatory in the acute phase. However, to date, no optimal treatment has been established which satisfies secure prevention of rerupture and ischemia simultaneously. Herein, we report a case of SAH due to BAD treated with proximal occlusion of basilar artery with superficial temporal artery (STA)-superior cerebellar artery (SCA) bypass, preventing rebleeding securely and ensuring adequate blood flow in the upper basilar region. CASE DESCRIPTION: A 48-year-old male presenting with headache and altered mental status was found to have SAH and BAD. To prevent rerupture, proximal occlusion of basilar artery with STA-SCA bypass using anterior transpetrosal approach was performed. The postoperative course was relatively good and there is no evidence of recurrent arterial dissection. CONCLUSION: Proximal occlusion of the basilar artery combined with STA-SCA bypass was successful in preventing rerupture of BAD and ensuring blood flow in the upper basilar region. Although there is controversy regarding acute treatment for ruptured BAD, direct proximal occlusion with sufficient revascularization using bypass skull base technique may be one of the optimal treatments even in this era of endovascular treatment.

Trapping, dome puncture, and direct suction decompression in conjunction with assistant superficial temporal artery- middle cerebral artery bypass to clip giant internal carotid artery bifurcation aneurysm.

BACKGROUND: Very large and giant aneurysms (≥20 mm) of the internal carotid artery (ICA) bifurcation (ICAbif) are definitely rare, and optimal treatment is not established. Endovascular treatments are reported as suboptimal due to difficulties of complete occlusion and tendencies to recanalization. Therefore, direct surgery remains an effective strategy if the clipping can be performed safely and reliably, although very difficult. CASE DESCRIPTION: Two cases of ICAbif aneurysms (>20 mm) were treated. Prior assistant superficial temporal artery (STA)-middle cerebral artery (MCA) bypass was performed to avoid ischemic complications during prolonged temporary occlusion of the arteries in both cases. In Case 1 (22-mm aneurysm), the dome was inadvertently torn in applying the clip because trapping had resulted in insufficient decompression. Therefore, in Case 2 (28-mm aneurysm), almost complete trapping of the aneurysm and subsequent dome puncture was performed, and the aneurysm was totally deflated by suction from the incision. This complete aneurysm decompression allowed safe dissection and successful clipping. CONCLUSION: Trapping, deliberate aneurysm dome puncture, and suction decompression from the incision in conjunction with assistant STA-MCA bypass can achieve complete aneurysm deflation, and these techniques enable safe dissection of the aneurysm and direct clipping of the aneurysm neck. Direct clipping with this technique for very large and giant ICAbif aneurysms may be the optimal treatment choice with the acceptable outcome if endovascular treatment remains suboptimal.

Recurrent Embolic Stroke Caused by Large Cavernous Carotid Aneurysm: Stroke Recurrence Prevention with High-Flow Bypass Followed by Proximal Occlusion.

Intracranial aneurysms may cause embolic stroke. Medical or surgical management is selected on an individual basis, as the optimal treatment strategy has not been established. A 79-year-old woman with a large cavernous carotid aneurysm suffered repeated embolic stroke after enlargement and partial thrombosis of the aneurysm, in spite of antiplatelet therapy. Coil embolization of the primitive trigeminal artery and ligation of the internal carotid artery (ICA) at the cervical portion followed by high-flow bypass from the cervical external carotid artery to the middle cerebral artery were performed. The aneurysm was thrombosed, and prevention of further stroke was achieved. Acute enlargement and thrombosis of large or giant cavernous carotid aneurysm may cause repeated embolic stroke, and requires emergent exclusion of the aneurysm from circulation by proximal ICA occlusion together with distal revascularization before devastating embolic stroke occurs.

High-flow bypass with radial artery graft followed by internal carotid artery ligation for large or giant aneurysms of cavernous or cervical portion: clinical results and cognitive performance.

High-flow bypass followed by ligation of the internal carotid artery (ICA) is an effective treatment, but the impact of abrupt occlusion of the ICA is unpredictable, especially on postoperative cognitive function. The present study evaluated the clinical results as well as cognitive performances after high-flow bypass using radial artery graft (RAG) with supportive superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, followed by ICA ligation. Ten consecutive patients underwent high-flow bypass surgery for large or giant ICA aneurysms of cavernous or cervical portion. Demographics, clinical information, magnetic resonance (MR) imaging, computed tomography, digital subtraction angiography (DSA), intraoperative somatosensory evoked potentials, neuropsychological examinations including the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Revised (WMS-R), and follow-up data were analyzed. The aneurysm was located on the cavernous segment in eight cases and cervical segment in two cases, and mean aneurysm size was 27.9 mm. Postoperative DSA demonstrated robust bypass flow from the external carotid artery to MCA via the RAG, and no anterograde flow into the aneurysm. No patient showed new symptoms after the operation. Follow-up clinical study and MR imaging were performed in nine patients and showed no additional ischemic lesion compared with preoperative imaging. Seven patients completed neuropsychological examinations before and after surgery. All postoperative scores except WMS-R composite memory score slightly improved. High-flow bypass followed by ICA ligation can achieve good clinical outcomes. Successful high-flow bypass using RAG with supportive STA-MCA bypass and ICA ligation does not adversely affect postoperative cognitive function.

Giant cavernous carotid aneurysm causing pituitary dysfunction: Pituitary function recovery with high-flow bypass.

BACKGROUND: Giant internal carotid artery (ICA) aneurysms extending into the sellar region, mimicking pituitary tumors, and causing pituitary dysfunction are relatively rare. Open surgery or endovascular treatment can treat these aneurysms, but achieving recovery of endocrine function is difficult. CASE DESCRIPTION: A 56-year-old man presented with giant aneurysm of the ICA causing pituitary impairment, leading to disturbance of consciousness due to hyponatremia. High-flow bypass from the cervical external carotid artery to the middle cerebral artery and ligation of the ICA at the cervical portion were performed. One year after the operation, his pituitary function recovered well; he was followed up as an outpatient without hormonal replacement therapy for 8 years after the operation. CONCLUSION: Giant ICA aneurysm causing pituitary dysfunction is relatively rare, but it is important to consider in the differential diagnosis for hypopituitarism. Treatment with high-flow bypass using radial artery graft can achieve both prevention of aneurysm rupture and recovery of pituitary function.

Middle cerebral artery dissection causing subarachnoid hemorrhage and cerebral infarction: Trapping with high-flow bypass preserving the lenticulostriate artery.

BACKGROUND: Spontaneous intracranial arterial dissection (IAD) is an increasingly important cause of stroke, such as subarachnoid hemorrhage (SAH) and hemodynamic or thromboembolic cerebral ischemia. IAD usually occurs in the posterior circulation, and is relatively rare in the anterior circulation including the middle cerebral artery (MCA). Various surgical and endovascular methods to reduce blood flow in the dissected lesion have been proposed, but no optimum treatment has been established. CASE DESCRIPTION: An 80-year-old woman with dissection in the M1 portion of the MCA manifesting as SAH presented with repeated hemorrhage and cerebral infarction in the area of the inferior trunk of the MCA. High-flow bypass to the MCA was performed and the dissecting lesion was trapped. Prevention of repeated hemorrhage was achieved, and blood flow was preserved to the lenticulostriate artery as well as the MCA area distal to the lesion. CONCLUSIONS: Treatment strategy for IAD of the MCA should be planned for each patient and condition, and surgery should be performed promptly to prevent critical rebleeding given the high recurrence rate. In addition, preventing re-rupture of the IAD, and preserving important perforators around the lesion and blood flow distal to the dissection should be targeted by the treatment strategy.

Clot-clearance rate in the sylvian cistern is associated with the severity of cerebral vasospasm after subarachnoid hemorrhage.

Rapid clot removal and clearance has been proposed as an effective tool for preventing cerebral vasospasm after subarachnoid hemorrhage (SAH). We examined the relationship between clot-clearance rate and the severity of cerebral vasospasm in 110 consecutive patients with aneurysmal SAH. We measured clot-clearance rates per day in the basal and Sylvian cisterns, and evaluated the presence of symptomatic vasospasm based on changes in clinical symptoms and the appearance of a new low-density area on a computed tomography (CT) scan. The severity of symptomatic cerebral vasospasm was associated with age and the SAH grade on admission; however, we observed no significant difference between these variables in patients with urokinase irrigation or fasudil hydrochloride treatment. The mean clot-clearance rates per day for patients with asymptomatic and permanent delayed ischemic neurological deficit were 41.9 and 41.5 %, respectively, in the basal cistern (P = 0.7358) and 37.7 and 23.9 %, respectively, in the Sylvian cistern (P = 0.0021). The reduced clot-clearance rate in the Sylvian cistern increased the risk of vasospasm-related infarction (P = 0.0093) and markedly reduced unfavorable outcomes (P = 0.0115).

[Relationship between the natural history of chronic subdural hematoma and enhancement of the inner membrane on post-contrast CT scan].

The purpose of this study was to determine the features and natural history of the inner membrane in CSDH (chronic subdural hemotoma) patients using pre- and post-contrast CT scans. Twenty-four patients with CSDH (28 hematomas) who underwent pre- and post-contrast CT scanning prior to surgery were studied. CSDH was classified according to the internal architecture as the homogeneous (HM) type, the laminar (LM) type, the separated (SP) type, and the trabecular (TR) type. For each type, the enhancement of the inner membrane, the outer membrane, and trabeculae was evaluated. Enhancement of the inner membrane develops as the stage of CSDH progresses. Although the inner membrane was not enhanced in the HM type, it was enhanced in almost all of the patients with the other types (p < 0.0001). In 13% of patients with the LM type, 29% with the SP type, and 40% with the TR type, the inner membrane was moderately or markedly enhanced. The outer membrane was not thickened in any patient. In 88% of the patients who had contralateral hemiparesis on admission and 42% of those who did not have hemiparesis, the inner membrane was clearly enhanced (p = 0.0166). This indicated that blood flow to the inner membrane from the pia matter induced hypoperfusion of the brain parenchyma beneath the hematoma in addition to the effect of direct compression. Contrast CT scanning may be useful for diagnosing the extent of enlargement of the inner membrane, predicting the risk of local brain damage, and evaluating the stage in the natural history of CSDH.