Hideki Oka

Direct Microsurgical Embolectomy for Acute Occlusion of the Internal Carotid Artery and Middle Cerebral Artery

BACKGROUND Surgical embolectomy is the most promising therapy for physically removing emboli from major cerebral arteries. However, it requires an experienced surgical team, time-consuming steps, and is not incorporated into acute stroke therapy. METHODS We established seamless collaboration between services, refined surgical techniques, and conducted a prospective trial of emergency surgical embolectomy. Surgical indications included the presence of acute hemispheric symptoms, absence of low-density area on computed tomography, evidence of internal carotid artery terminus or proximal middle cerebral artery occlusion, and availability of resources to start surgery within 3 hours of symptom onset. The indications were confirmed by an interdisciplinary team. We assessed revascularization rates, time from admission to surgery and from surgery to recanalization, procedural complications, and clinical outcomes. RESULTS Between 2005 and 2014, 14 consecutive patients with acute proximal middle cerebral artery or internal carotid artery terminus occlusion underwent emergency surgical embolectomy. All patients showed complete recanalization. Twelve patients survived and 7 had fair functional outcome (Rankin Scale score, ≤3). No significant procedural adverse events occurred. The mean times from admission to start of surgery, from surgery to recanalization, and from onset to recanalization were 14 minutes, 79 minutes, and 223 minutes, respectively. CONCLUSIONS Our results suggest that microsurgical embolectomy can rapidly, safely, and effectively retrieve clots and deserves reappraisal, although the choice largely depends on local institutional expertise.

Pros and Cons of Tentative Clipping in Intracranial Aneurysm Surgery: Review of 867 Direct Clippings in Single Institution

OBJECTIVE In direct aneurysm surgery, tentative clipping is frequently applied to facilitate aneurysm dissection. However, no systemic review on the pros and cons of tentative clipping has been conducted. This study aimed to investigate the efficacy and concerns of tentative clipping. METHODS A total of 867 direct clippings in 737 patients were performed to treat intracranial aneurysms between 1994 and 2015. We retrospectively investigated the frequency, purpose, location, and adequacy of tentative clipping. RESULTS Tentative clipping was performed in 149 of the 867 aneurysms that were clipped (17.2%). The purpose of tentative clipping was to dissect an aneurysm in 141 (94.6%), separate the vessels from the surface of a sac in 5 (3.4%), and prevent slipping of the final clip in 3 (2.0%) cases. Further dissection revealed that tentative clipping completely excluded the blood flow into the aneurysm in 126 (84.6%) of the 149 cases and incompletely shut it out in 23 (15.4%) cases. Five (21.7%) of the 23 patients with incomplete clipping had intraoperative aneurysm ruptures subsequently. CONCLUSIONS Tentative clipping facilitates dissection of the aneurysm sac from the surrounding structure but can occasionally lead to intraoperative rupture. Before applying tentative clips, surgeons should prepare for temporary clipping or additional tentative clipping in case of a rupture.

Strictly Limited Orbital Pain as Sentinel Headache of Subarachnoid Hemorrhage

BACKGROUND The headache preceding an intracranial aneurysm rupture is called a sentinel headache (SH), and it is characterized by a sudden, intense, and persistent headache. As subarachnoid hemorrhage (SAH) often develops within several weeks of SH, its rapid diagnosis and treatment can improve the prognosis. CASE DESCRIPTION A 52-year-old woman with migraine in her medical history visited the outpatient clinic due to left orbital pain. There was no neurologic deficit. Although magnetic resonance imaging examination found no SAH, a left internal carotid artery-posterior communicating artery bifurcation aneurysm was detected by magnetic resonance angiography. Ten days after the onset of orbital pain, the patient consulted our hospital for a second opinion. We scheduled an elective clipping because the irregular shape of the aneurysm had a high risk of rupture. On the day before surgery, the aneurysm ruptured and led to SAH. Clipping was performed immediately. The patient was discharged with no neurologic deficit. CONCLUSION Clinicians must take into consideration that unilateral orbital pain, though atypical, may be a symptom of SH.

Unusual Clinical Sequelae of Kawasaki Disease—Symptomatic Extracranial Internal Carotid Stenosis in Young Adult

BACKGROUND Kawasaki disease (KD) is an acute systemic vasculitis that primarily affects the coronary artery, but it does not commonly affect the carotid artery. Cerebral infarction (CI) with internal carotid artery stenosis (ICS) in patients with KD has not been reported until now. We report a patient with CI as a remote-phase complication of KD. CASE PRESENTATION A 32-year-old man presented with impaired consciousness. Magnetic resonance imaging and digital subtraction angiography confirmed CI and ICS. He successfully underwent carotid endarterectomy. The resected plaque had pathologic findings of KD, which suggested that the internal carotid artery suffered from chronic inflammation. CONCLUSION KD in childhood may cause symptomatic ICS as a sequela of a remote phase.

Microsurgical Removal of Snagged Stent Retriever During Endovascular Embolectomy for Acute Ischemic Stroke

BACKGROUND Catheter-based endovascular thrombectomy has gained popularity for use in patients with acute large-vessel occlusion; however, various complications have been reported. Herein, we present a unique, serious procedure-related complication. CASE DESCRIPTION A 91-year-old woman with acute middle cerebral artery (MCA) occlusion underwent endovascular thrombectomy with a stent retriever, but the device could not be retrieved from the horizontal segment of MCA during the procedure. Subsequently, she underwent emergency craniotomy. The lodged stent was extracted with microforceps using a counter-stretch of the vessels, so as not to avulse the perforating arteries. The stent device was retrieved uneventfully through a sheath introducer that was inserted through the femoral artery. Postprocedural indocyanine green video angiography showed complete recanalization of the MCA and internal cerebral artery. CONCLUSIONS This is a rare case in which successful open surgery was performed to retrieve a snagged stent retriever, with successful recanalization of the large cerebral artery occlusion.

Chronic headache caused by a titanium fixation plate: Report of two cases

Background: We report two patients with chronic postcraniotomy headache who showed rapid alleviation of pain after removal of titanium miniplates. Case Description: (Case 1) A 26-year-old woman underwent a right frontal craniotomy and excision of the entire cerebral cavernous malformation. Eleven years later, she developed headache. The titanium plate was removed and the patient presented complete amelioration of headache. (Case 2) A 50-year-old man underwent an aneurysm clipping via the lateral supraorbital approach of the left side. One year later, he complained about throbbing pain. Removing the titanium plate led to complete relief of the headache. Conclusion: Titanium miniplate fixation may irritate the deep division of the supraorbital nerve and may cause a chronic headache. Here, we propound the idea that, postcraniotomy, titanium miniplates should not be placed above the temporal fusion line.

KRIT1 mutations in three Japanese pedigrees with hereditary cavernous malformation

Cerebral cavernous malformation is a neurovascular abnormality that can cause seizures, focal neurological deficits and intracerebral hemorrhage. Familial forms of this condition are characterized by de novo formation of multiple lesions and are autosomal-dominantly inherited via CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 mutations. We identified three truncating mutations in KRIT1 from three Japanese families with CCMs: a novel frameshift mutation, a known frameshift mutation and a known splice-site mutation that had not been previously analyzed for aberrant splicing.