According to the Japan Carotid Atherosclerosis Study, only 3.8% of all medical institutes use patch grafts for carotid endarterectomy (CEA). Patch grafting requires techniques, but is reportedly associated with a lower incidence of postoperative restenosis and recurrent stroke and is considered effective in patients undergoing CEA.

Since 1999, our institute has actively used patch grafts (Hemashield®) in patients undergoing CEA. Moreover, by September 2016, we had performed 105 CEAs with Hemashield patch grafts in 98 of 111 patients who received 119 CEAs. Herein, we report the surgical techniques and notable points along with treatment outcomes, including long-term outcomes beyond 2 years. The technical point to note is that when the Hemashield patch to be grafted is too large, it is deflected, thereby creating a small gap between the patch and internal carotid artery, resulting in bleeding after declamping. The patch was cut at a distance of 1 mm from both ends for seam allowance. For suturing, the continuous suture technique is used, with stay sutures placed at both ends. The suture should be evenly spaced (1–1.5 mm) and applied such that the inner line of the artery and the inside of the Hemashield patch are con-joined. Bleeding after declamping can be avoided by maintaining an appropriate tension and spacing during suturing.

Regarding treatment outcomes, 86 CEAs from 82 patients were followed-up for at least 2 years, and the degree of carotid artery stenosis was assessed using carotid ultrasound. Based on the European Carotid Surgery Trial criteria, mild (0–50%), moderate (50–69%), and severe (≥70%) stenoses were identified in 79 (91.8%), 5 (5.8%), and 3 (3.4%) CEAs, respectively. Stroke occurred in only three CEAs (3.4%), which comprised lacunar stroke ipsilateral to the CEA, brainstem stroke, and atheromatous cerebral thrombosis in the posterior cerebral artery territory. Consequently, the outcomes of CEA with patch grafting were considered favorable.

Background: There have been few reports on carotid veins in carotid endarterectomy (CEA). We have been working on CEA using the internal and external carotid veins, and we report a method of exposing the carotid artery in the neck by paying attention to and using the carotid veins.

Methods: We performed CEA using a transverse incision utilizing the crease in the skin of the neck from the cosmetic viewpoint of less noticeable postoperative wounds. The difference between CEA using a horizontal incision and CEA using a vertical incision, which is usually performed, is the creation of a skin flap after the horizontal skin incision to change the direction of the vertical dissection similar to a vertical incision. The external jugular vein is thought to be useful for the creation of a skin flap and has been used for this purpose. Therefore, we report a method of creating a skin flap.

Although the carotid triangle has been reported to be useful for exposing the carotid artery, there are few reports on where and how to safely dissect the carotid triangle. In order to avoid damage to the internal carotid artery and the superior laryngeal nerve, we report a new method of carotid triangle dissection using the common facial vein which may be safe and useful for carotid exposure maneuvers.

Restenosis after carotid artery stenting (CAS) can occur in the chronic phase; however, the characteristics, risk factors, and timing of occurrence remain unclear. This study aimed to analyze the features and risk factors of restenosis and to examine follow-up after CAS. Among 216 lesions for which CAS was performed between April 2008 and May 2018, 182 that were followed up for ≥12 months were included in this retrospective analysis. The follow-up period was 12-128 months (mean 52.7 months). The incidence of restenosis was 7.1% (13/182 lesions), including eight cases that developed restenosis within 12 months and five cases that occurred ＞12 months after CAS. The longest period until development is 83 months after CAS. There were 4 cases of symptomatic restenosis (2.2%), including 3 that occurred within 6 months, of which 2 occurred approximately one month after reduction of antithrombotic agents. In the multivariate analysis, younger age was the only risk factor significantly associated with restenosis (p=0.011, OR 1.13). The long-term risk of ipsilateral ischemic stroke was significantly higher in the restenosis (＋) group than in the restenosis (−) group (p=0.0011, OR 18.3). These results show that restenosis after CAS is more frequent within 12 months than after 12 months but can occur after long-term follow-up and may cause ipsilateral ischemic stroke. Restenosis may be particularly likely after the reduction of antiplatelet agents, and careful observation is important in the first 12 months after CAS.

Background: The effectiveness of thrombectomy for ischemic stroke 6–24 hours after a patient was last known to be well has been shown in recent randomized trials. It is important to select eligible patients for thrombectomy ＞ 6 h after the onset of ischemic stroke to perform the endovascular procedure safely.

Objective: This study aimed to evaluate the efficacy of distal vessel imaging over clots using pial collateral formation on 3D-rotational digital subtraction angiography (DSA) in assessing if thrombectomy is indicated in patients with middle cerebral artery (MCA) occlusion.

Methods: Data from patients who underwent endovascular thrombectomy (EVT) for acute MCA occlusion within 8 h of the onset of ischemic stroke with conventional DSA between January 2015 and December 2017 were collected (the conventional group). For the 3D-DSA group, similar data were collected from patients who underwent EVT for acute MCA occlusion within 16 h of onset between January 2018 and December 2018. The patients in the 3D-DSA group had a mismatch between the high-intensity area on diffusion-weighted magnetic resonance imaging (MRI) and the occluded area with good pial collaterals on evaluation of 3D-rotational DSA. We visualized the distal branches over the clots using 3D-rotational DSA before thrombectomy with a stent retriever. Distal vessel imaging was created from the maximum intensity projection (MIP) image of the pial collaterals acquired by 5 s 3D-rotation with an 18 s delay and 33% diluted contrast media. Clinical data, including baseline National Institutes of Health Stroke Scale (NIHSS) score and diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) at admission and modified Rankin Scale (mRS) score at 30 days, as well as procedural data including onset-to-puncture time, procedural time, Thrombolysis In Cerebral Infarction (TICI) score, and complications were analyzed, and the two groups were compared for each variable.

Results: A total of 37 patients were enrolled in this study. Approximately 26 patients were in the conventional group, and 11 were in the 3D-DSA group. Thrombectomy for M2 occlusion was performed in 7 of the 11 (63.6%) patients in the 3D-DSA group and nine of the 26 (34.6%) patients in the conventional group. There were no significant differences between the two groups for all variables (age (p=0.65), sex (p=1), baseline NIHSS (p=0.55), DWI-ASPECTS (p=0.86), IV t-PA (p=0.16), on-set-to-puncture time (p=0.18), procedural time (p=0.14), TICI (p=0.34), mRS at 30 days (p=0.81), and symptomatic ICH (p=1)). The median interval between the time the patient was last known to be well and puncture was 380 min (interquartile range: IQR 130-600) in the 3D-DSA group compared with 210 min (IQR 165-259) in the conventional group. The rate of mRS 0-2 at 30 days was 73% in the 3D-DSA group compared with 54% in the conventional group.

Conclusion: Distal vessel imaging over clots using pial collateral formation on 3D-rotational DSA may assist with the decision to perform a thrombectomy more than 6 h after the onset of ischemic stroke in patients with MCA occlusion.

Right aortic arch is a rare congenital anomaly. We present a case of staged angioplasty for stenosis of the right internal carotid artery of the right aortic arch.

A 66-year-old man visited our hospital after experiencing inarticulation. Magnetic resonance imaging (MRI) of the head showed acute cerebral infarction in the right middle cerebral artery region, and magnetic resonance angiography (MRA) showed poor visualization of the right internal carotid artery. Cerebral angiography revealed severe stenosis of the right internal carotid artery and right aortic arch. We performed a staged angioplasty to avoid postoperative hyperperfusion syndrome.

It is crucial to have sufficient knowledge of the anatomy of the right aortic arch, keeping it in mind constantly since it may be rarely detected during cerebral angiography and emergency catheter treatment, which requires ingenuity for procedure and device selection.

Carotid cross-clamping is unavoidable in carotid endarterectomy (CEA), and some cases present neurological symptoms due to ischemic intolerance, but most improve immediately. Furthermore, hyperperfusion, in addition to ischemic insult, is reported as the cause of the postoperative neurological deficit. We report a case of internal carotid artery stenosis with prolonged neurological symptoms without cerebral infarction or hyperperfusion findings on magnetic resonance imaging (MRI) after the CEA.

A 73-year-old woman diagnosed with left internal carotid artery stenosis was admitted to our hospital for transient aphasia. Preoperative magnetic resonance angiography (MRA) showed the absence of the A1 segment of the right anterior cerebral artery and the left posterior communicating artery. Additionally, both of those arteries were not visualized by the right carotid and left vertebral angiograms with Matas and Alcock maneuvers. We performed CEA with an intraluminal shunt, and carotid cross-clamping was performed for approximately 16 minutes. On the day after the operation, the patient developed right-sided hemiparesis and aphasia and no hemorrhagic or ischemic lesions were observed on computed tomography and MRI. However, hyperperfusion in the thalamus and left temporo-occipital region was identified through arterial spin labeling (ASL). Her neurological symptoms gradually improved, and the MRI showed no infarction and resolution of the hyperperfusion in the thalamus and left temporo-occipital region 3 days after the operation. The neurological symptoms persisted for approximately 90 hours and disappeared completely thereafter.

Obtaining information about cross-clamping intolerance before surgery may reduce the ischemic complication rate. Additionally, non-convulsive status epilepticus (NCSE) should be considered as the cause of postoperative neurological symptoms, and ASL findings may assist in diagnosing NCSE.

The recurrence of an oculomotor nerve palsy due to invasion of the oculomotor nerve by coil loops extruded from a previously embolized internal carotid-posterior communicating artery aneurysm (IC-PC AN) is extremely rare.

A 69-year-old woman presented with a right oculomotor nerve palsy. Magnetic resonance angiography revealed a right IC-PC AN. Coil embolization was performed, and the oculomotor nerve palsy resolved. However, 4 and a half years later, the diplopia returned. Digital subtraction angiography revealed a slight recurrence of the aneurysm at the neck, with coil loops protruding to the outside of the coil mass. During microsurgery, the extrusion of previously embolized coils was observed. The extruded coil loops were embedded in the right oculomotor nerve. The aneurysm was clipped at the neck, the coils were cut at the aneurysm sac, and decompression of the oculomotor nerve was accomplished without removing the coils. The oculomotor nerve palsy did not improve after surgery.

It is still controversial whether microsurgical clipping or endovascular coil embolization is better for treating unruptured IC-PC AN causing oculomotor nerve palsy. If coil embolization is selected, there is a risk of oculomotor nerve palsy recurrence due to coil extrusion, and long-term follow-up is necessary.

Objective: To report a case in which acute exacerbation of cervical spondylotic myelopathy, caused by hyperdorsiflexion of the neck during coil embolization, was suspected.

Case Presentation: A 48-year-old man experienced a sudden headache and was taken to another hospital for emergency treatment. Subarachnoid hemorrhage was diagnosed following a head computed tomography (CT), and the patient was transferred to our hospital.

An aneurysm of ⌀4.8 × 3.5 mm in the anterior direction of the anterior communicating artery (AcomA) was revealed using computed tomography angiography (CTA). Severe left upper limb paralysis and perceptual disorder were observed immediately after the patient underwent emergency coil embolization under general anesthesia; however, a head magnetic resonance imaging (MRI) revealed no obvious ischemic changes. Cervical hyperextension was performed to create a working angle during the operation, and an additional cervical spinal MRI suggested cervical spondylotic myelopathy. Left upper limb paralysis gradually improved, and he was discharged home with a modified Rankin score of 0 (mRS0) on the 73rd day of hospitalization.

Conclusion: Being aware of the risk of cervical spondylotic myelopathy or spinal cord injury due to hyperextension is necessary when dorsiflexing the neck to create a working angle.

Posterior reversible encephalopathy syndrome with spinal cord involvement (PRES-SCI) is a newly reported entity that is suspected when lesions with altered signals expand to the spinal cord. All previously reported cases of PRES-SCI were successfully treated with medical treatment alone. herein, we describe a case of PRES-SCI with acute obstructive hydrocephalus that required emergency ventricular drainage. A 45-year-old man presented to our hospital with a mildly impaired consciousness and nausea. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed extensive edema in the occipital lobe, cerebellum, and upper cervical cord with acute obstructive hydrocephalus. The patient was diagnosed with PRES-SCI, and emergency external ventricular drainage was performed to alleviate the elevated intracranial pressure, followed by management with antihypertensive drugs. The brain and spinal cord edema gradually improved. The patient was successfully discharged without neurological deficits. Since obstructive hydrocephalus is a potential complication, adequate timing of surgical intervention is indispensable for the management of PRES-SCI.

Recent reports have revealed cases of contrast-induced encephalopathy after endovascular therapy. Neurotoxicity caused by blood brain barrier (BBB) disruption or contrast media migration into the brain cortex and subarachnoid space is an important factor, but details are unknown. Here, we present two cases of contrast-induced encephalopathy that developed after endovascular therapy, and findings of hypoperfusion followed by hyperperfusion on single photon emission computed tomography (SPECT).

Case 1: A 63-year-old woman underwent flow-diverter stenting for treatment of an unruptured aneurysm. Owing to difficulty in navigation of the microcatheter into the distal parent artery, the operation time was extended. She developed contrast-induced encephalopathy after the procedure, and her symptoms disappeared three days after the procedure. On the day after the procedure, SPECT showed decreased uptake in the region of the left middle cerebral artery (MCA) territory. Seven days after the procedure, SPECT showed increased uptake in the same area.

Case 2: A 77-year-old man underwent carotid artery stenting using MOMA Ultra for treatment of asymptomatic left internal carotid artery stenosis. Ischemic complications or hyper-perfusion syndrome was negative on examination. Therefore, we diagnosed him with contrast-induced encephalopathy. The following day, SPECT showed decreased uptake in the left MCA territory. He recovered nine days later. At this time point, SPECT showed increased uptake in the same area.

Contrast-induced encephalopathy is a rare complication, and recovery is natural in most cases. SPECT findings in our cases suggest that rapid changes in the cerebral blood flow and/or metabolism are seen in the early stages of contrast-induced encephalopathy.

Optimal perioperative management in patients with idiopathic thrombocytopenic purpura (ITP) necessitates a therapeutic approach to increase the platelet count and reduce the risk of hemorrhagic complications. We report a case of an unruptured cerebral aneurysm accompanied by ITP in a patient who received high-dose intravenous gamma globulin (IgG) therapy before clipping surgery. A 53-year-old man underwent clipping surgery for an unruptured anterior communicating artery aneurysm, which showed enlargement during follow-up. The patient was diagnosed with chronic ITP three years before presentation. However, he did not receive any medication and was only followed up. The patient had a history of anaphylactic reaction secondary to platelet transfusion; therefore, we administered high-dose IgG therapy to increase the platelet count perioperatively. High-dose intravenous IgG therapy (400 mg/kg/day) was administered for five consecutive days before clipping surgery. As a result, the patient’s platelet count increased from 1.9 × 10⁴/mm³ at admission to 12.7 × 10⁴/mm³ two days preoperatively. He underwent successful clipping surgery without any peri- or post-operative complications. His platelet count was maintained at ＞10.0 × 10⁴/mm³ perioperatively and gradually reduced to 5.5 × 10⁴/mm³ three weeks postoperatively. IgG therapy may be a useful treatment strategy for perioperative management in patients with ITP, particularly in cases that can be carried out semi-electively, such as in the present case.

Objective: We report a case of endovascular management of a tentorial dural arteriovenous fistula (dAVF) with a pial feeder.

Case presentation: A 36-year-old man presented with a headache and alexia. Angiograms revealed a tentorial dAVF, which was supplied by both pial and dural feeders and drained directly into the leptomeningeal vein. Transarterial embolization (TAE) with n-butyl-2-cyanoacrylate via the pial feeder from the left posterior cerebral artery completely obliterated the shunt without complications.

Conclusion: TAE of dural feeders in dAVF with both pial and dural feeders has a significant risk of severe hemorrhagic complications. To avoid these complications, TAE of pial feeders should precede TAE of dural feeders.

Microsurgical clipping remains a valuable option for selected patients with posterior circulation cerebral aneurysms. Here, we present a case of a ruptured saccular aneurysm arising from the lower portion of the basilar artery, which was treated with direct clipping using the posterior transpetrosal approach. We describe the importance of the skull base technique to expand the working field in which both parent artery control and fine dissection can be performed. Moreover, careful use of a brain retractor can protect the brain while improving safety.