Akihiko Hino

Changes in endothelial nitric oxide synthase mRNA during vasospasm after subarachnoid hemorrhage in monkeys.

OBJECTIVE We attempt to determine whether changes in messenger ribonucleic acid (mRNA) for nitric oxide synthase (NOS) and soluble guanylate cyclase, enzymes that mediate endothelium-dependent vasodilation in cerebral arteries, occur after subarachnoid hemorrhage (SAH) in monkeys. METHODS Baseline cerebral angiograms were obtained, and right-sided SAH was induced by microsurgically placing autologous blood clot against the right anterior circle of Willis in seven monkeys. Seven days later, angiographic studies were repeated and the animals were killed. Right (vasospastic) and left (control) middle cerebral arteries and underlying cortex were removed. The competitive reverse transcriptase polymerase chain reaction was used to quantify mRNA for soluble guanylate cyclase and two isoforms of constitutive NOS in these tissues. RESULTS Comparison of angiograms at baseline and after 7 days showed a 41 +/- 7% (mean +/- standard error of the mean, P < 0.05, Wilcoxon test) decrease in diameter of the right middle cerebral artery. After the animals were killed, comparison of right and left middle cerebral arteries showed a 56 +/- 11% decrease (P < 0.005, paired t test) in endothelial NOS mRNA. There was a 142 +/- 39% (P < 0.05) increase in right cortex endothelial NOS mRNA compared to the left cortex. There were no significant differences between right and left sides in mRNAs for soluble guanylate cyclase or brain NOS. CONCLUSION Decreased endothelial NOS mRNA in cerebral arteries 7 days after SAH may be caused by endothelial cell damage and could contribute to vasospasm after SAH. Increased endothelial NOS in brain tissue may reflect a compensatory vasodilator mechanism of the brain against the cerebral ischemia associated with vasospasm and SAH.

TRAINING IN MICROVASCULAR SURGERY USING A CHICKEN WING ARTERY

OBJECTIVEMicroarterial anastomosis is now seldom performed for treatment of atherosclerotic occlusive cerebrovascular disease. However, a small but significant number of procedures still require this technique. When a surgeon’s clinical experience is limited, regular practice is required to maintain and improve surgical skills. The present training system involves passage from suturing of synthetic materials (such as Silastic tubes) to practice with experimental living animals or cadavers. However, these methods are neither convenient nor practical for daily exercises and rehearsals. I present a unique training exercise for microarterial anastomosis, using a chicken wing artery. METHODSA brachial artery can be extracted from a chicken wing. The artery is 5 to 6 cm long and measures approximately 1 mm in diameter. The artery can be used to practice end-to-end, end-to-side, or side-to-side anastomosis under the microscope. RESULTSSeveral advantages are noted: the materials are cheap, convenient to manage, and easy to obtain, and neither specific facilities to maintain living animals nor anesthesia is needed. Moreover, the diameter and structure of the material are identical to those of human cortical vessels, making the rehearsal quite similar to the actual surgical experience. CONCLUSIONThis exercise is useful not only for young surgeons who wish to learn microsurgical techniques but also for more experienced surgeons who need to maintain or improve their skills.

Increased Expression of Endothelin B Receptor mRNA Following Subarachnoid Hemorrhage in Monkeys

These studies tested the hypothesis that the cerebral vasospasm that follows subarachnoid hemorrhage (SAH) is due to alterations in endothelin (ET) and ET receptor expression. Eight monkeys underwent cerebral angiography and induction of SAH. Angiography was repeated 7 days later to confirm the presence of cerebral vasospasm, and animals were killed. RNA was isolated from right (vasospastic) and left (control) side middle cerebral arteries and surrounding cerebral cortex. The levels of prepro (PP) ET-1 (ppET-1) and ppET-3 and ETA and ETB receptor mRNAs were determined using a quantitative reverse transcriptase polymerase chain reaction-based assay. ET-1 peptide was also measured in CSF at baseline and after 7 days. Specific agonist binding to ETA and ETB receptors in both middle cerebral arteries and in surrounding brain cortex was measured in three animals by autoradiographic binding assays. Levels of ETB receptor mRNA were 3.4 ± 2.2-fold higher in the right than in the left cerebral arteries (p < 0.01). There were no significant differences in the levels of ppET-1, ppET-3, or ETA receptor mRNA in cerebral arteries. ET-1 peptide was not elevated in CSF. Levels of ETA and ETB receptor mRNAs were 2.6 ± 1.1- and 2.1 ± 1.3-fold higher, respectively, in the right than in the left cerebral cortex, while the level of ppET-3 mRNA was 2.1 ± 1.0-fold lower. There were no differences in ppET-1 mRNA levels between right and left cerebral cortex. Binding to ETA and ETB receptors in cerebral arteries and cortex did not differ significantly between right and left sides. These results do not support the hypothesis that overexpression of ET-1 is the principal cause of vasospasm, but rather they suggest that SAH causes complex changes in the ET system that together are responsible for the cellular response to SAH.

Tris-acryl gelatin microspheres versus gelatin sponge particles in uterine artery embolization for leiomyoma

Background Tris-acryl gelatin microspheres (TAGM) and gelatin sponge particles (GS) have been used in uterine artery embolization (UAE) for leiomyoma. No direct comparisons of both embolic agents have been reported. Purpose To compare the outcomes of UAE with TAGM with those of UAE with GS for uterine leiomyoma. Material and Methods This was a non-randomized, single-institute, non-inferiority study. Between July 2008 and August 2015, 67 consecutive patients with symptomatic leiomyoma underwent UAE. GS was used for the first 49 patients and TAGM was used for the following 18 patients. The primary endpoint was tumor infarction on contrast-enhanced magnetic resonance imaging (MRI) 1 week after UAE. The secondary endpoints were changes in symptoms and quality-of-life scores with UFS-QOL questionnaires at 4 months, and adverse events (AEs) in the 4 months after UAE. Results The baseline characteristics of both groups were similar. Complete or nearly complete tumor infarction (≥90%) was achieved in 94.4% (17/18) of the TAGM group and 93.6% (44/47) of the GS group. This difference (0.8%; 95% CI, –11.9% to 13.5%) indicated the non-inferiority of the TAGM group to the GS group, with a pre-specified non-inferiority margin of 20%. No significant differences were observed in improvements in symptoms or quality-of-life scores at 4 months (P = 0.56 and P = 0.19) or in 4-month AEs (P = 0.29). Conclusion The outcomes of UAE with TAGM were comparable to those of UAE with GS, suggesting that both embolic agents are acceptable for the treatment of leiomyoma.

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.