The need of minimally invasive surgeries for unruptured cerebral aneurysms remains unclear. Between 2010 and 2016, 75 patients with unruptured cerebral small aneurysms underwent direct neck clipping via the distal trans-sylvian keyhole approach by the first author. After the surgery, all patients recovered well without any neurological deterioration. Compared to patients who underwent conventional craniotomy, those who underwent keyhole surgery tended to be more satisfied in terms of postoperative pain and cosmetic results. Furthermore, keyhole surgery was found to be associated with less postoperative temporal muscle atrophy. Our keyhole technique provides an important contribution to the list of less invasive surgical procedures for unruptured cerebral aneurysms.

The retrograde suction decompression (RSD) technique is highly effective for direct clipping of large or giant intracranial aneurysms (ANs) in the internal carotid artery (ICA) because it can achieve proximal parent vessel control, improve AN neck visualization by shrinking the AN, and help peel off perforating arteries. The purpose of this study was to describe the technique and surgical results of RSD for middle-sized (<10 mm) AN of the ICA and to recommend the proactive use of RSD for middle-sized ANs of the ICA.

Materials and Methods: We performed clipping of 354 middle-sized (<10 mm) ANs of the ICA C1-3 portion (ophthalmic and anterior choroidal arteries, posterior communicating artery, and cave) between April 2012 and January 2017. We retrospectively reviewed the clinical data and treatment summaries of 15 cases (4.2%) treated with RSD-assisted clipping and describe the RSD technique. One male and 14 female patients aged 33-80 years (mean, 58.1 years) were included in the study.

Case Presentation: <Case 1> A 70-year-old-woman with a right internal carotid (IC)-posterior communicating artery AN showed no symptoms. The AN was 8.7 mm in maximum diameter, projected inferiorly, and preoperative computed tomographic angiography (CTA) revealed no atherosclerosis of the parent vessel. However, during operation, we recognized that the intracranial parent vessel was difficult to secure because of its significant atherosclerosis, the aneurysmal wall was fragile, and the AN was located beneath the tentorial edge. Thus, on the basis of the intraoperative findings, we judged the necessity of the RSD technique for safely freeing the perforating arteries from adhesions.

<Case 2> A 42-year-old woman with an anterior wall AN of the left IC C2 portion showed no symptoms. The AN had a maximum diameter of 6.2 mm. Preoperative CTA and magnetic resonance imaging findings indicated that the left optic nerve was displaced superiorly by the AN. Therefore, before attempting an approach to the AN, we decided to practice the RSD technique using the preoperative diagnostic images.

Results: All the patients except one had a good outcome, and the neurological finding in one patient was the same as that before operation.

Conclusions: For middle-sized ANs, the RSD technique is a useful procedure to achieve proximal vessel control, to soften and shrink the aneurysmal sac, and to provide a wide and clean operative field that allows for a safe clip placement. During operation, we confidently recommend performing the RSD technique for safely freeing perforating arteries from adhesions to the fragile aneurysmal wall, except for small ANs.

Guidelines for the treatment of unruptured internal carotid artery anterior wall (dorsal) aneurysms (ICDAs) are yet to be discussed. Here, we report the clinical findings and outcomes of three surgically treated cases of unruptured ICDAs (1 case of the saccular type and 2 cases of the blister-like red wall type) and discuss the guidelines for treatment.

Case 1 was a 51-year-old woman who presented with transient visual field defects in the left eye. We diagnosed her with compression of the left optic nerve by an unruptured ICDA approximately 5 mm in diameter and subsequently scheduled an operation. Although we had planned to follow the guidelines for the surgical treatment of a ruptured ICDA (extracranial-intracranial [EC-IC] bypass + trapping), the aneurysm was found to be of the saccular type, and could be treated by neck clipping. After surgery, the patient no longer had visual field defects, and was discharged to return home with a modified Rankin Scale (mRS) for neurologic disability score of 0. No recurrence of aneurysms has been detected at 4 years post-surgery. Case 2 was an 84-year-old woman who presented with Hunt and Kosnik (H&K) grade 4 subarachnoid hemorrhage (SAH). We diagnosed her with a ruptured anterior communicating artery aneurysm. During emergency surgery, we found an unruptured ICDA of the blister-like red wall type on the right internal carotid artery. After clipping the ruptured aneurysm, we performed muscle wrapping of the ICDA. No growth of the ICDA was detected by three-dimensional-computed tomography angiography (3D-CTA) 1 month after surgery, and the patient was transferred to another hospital with an mRS score of 2. The ICDA has not ruptured at 3.5 years post-surgery. Case 3 was a 48-year-old woman who presented with H&K grade 3 SAH. We diagnosed a rupture of a left internal carotid-posterior communicating artery aneurysm. During emergency surgery, we found an unruptured ICDA of the blister-like red wall type on the left internal carotid artery. Similar to Case 2, after clipping the ruptured aneurysm, we performed muscle wrapping of the ICDA. The patient was discharged with an mRS score of 0. No growth of the aneurysm has been detected at 1 year post-surgery. ICDAs for which arterial dissection cannot be ruled out should be treated cautiously following the ruptured aneurysm treatment strategy, even if the aneurysm is unruptured. However, it may be possible to treat unruptured saccular type-ICDAs by clipping alone, similar to unruptured aneurysms located elsewhere. Moreover, muscle wrapping may be effective in preventing the growth and the rupture of unruptured blister-like red wall type ICDAs encountered incidentally during surgery, at least in the shortterm. Both treatment strategies need to be validated by more cases and longer follow-up periods.

Extracranial-to-intracranial high-flow bypass (HFB) associated with intentional internal carotid artery occlusion has been mainly applied for complex intracranial aneurysms, including symptomatic cavernous sinus segment, blood blister-like, and large unclippable paraclinoid aneurysms. Although the surgical procedure of HFB has been established, some variations in the surgical procedure have been reported.

The purpose of the present study was to discuss the variations in the surgical procedure of HFB and their efficacy.

Twenty-five consecutive patients who underwent HFB between January 1, 2010 and March 31, 2017 were included in this study. The type and route of the graft vessel, creating an auxiliary bypass before the main graft anastomosis, and systemic heparinization were discussed as variations in the procedure.

The radial artery (RA) was used as a graft vessel in 21 patients, and the greater saphenous vein, in 4. The graft route was constructed from the proximal external carotid artery to the middle cerebral artery through the infratemporal fossa in all cases. In the upper cervical portion, a lower route between the hypoglossal nerve and posterior berry of the digastric muscle was chosen in 23 patients. In contrast, an upper route superior to the digastric muscle was used in 2 patients. Auxiliary bypass was used in only 2 patients who needed temporary occlusion of the dominant M2 during M2-RA anastomosis. Systemic heparinization was performed in all cases.

Postoperatively acute graft vessel occlusion was found in one case. Cerebral infarction after HFB was detected in 2 cases. Chronic graft vessel occlusion occurred in 1 patient, with no clinical symptom. No intracranial hemorrhagic complication accompanied by systemic heparinization was found.

HFB is an effective procedure to overcome complex intracranial aneurysms. Although the surgical procedure has been established, some variations are often adopted. Acquiring surgical skill in the procedural variations is essential for successful postoperative results.

Intra-arterial indocyanine green (IA-ICG) angiography is a very useful tool for cerebrospinal vascular surgery, especially for determination of the recipient artery in bypass surgery or identification of vascular malformation. In the present report, we describe two patients whose cerebrospinal vascular disorders were successfully treated with the assistance of intraoperative selective IA-ICG angiography in a neurosurgical hybrid operating suite.

Case 1: A 42-year-old man presented with convulsions. Conventional cerebral angiography demonstrated a giant (32 mm) partially thrombosed aneurysm at the M2-M3 portion of the left middle cerebral artery. Endovascular aneurysm occlusion under superficial temporal artery-middle cerebral artery protection bypass was planned. Superselective IA-ICG angiography was performed via a microcatheter positioned proximal to the aneurysm to select the best candidate for the recipient artery located distal to the aneurysm. The bypass surgery was successfully completed, and endovascular occlusion of the aneurysm was accomplished using detachable coils.

Case 2: A 70-year-old man presented with weakness and bilateral sensory disturbance of the lower extremities caused by recurrence of spinal dural arteriovenous fistula (dAVF). Intraoperative angiography demonstrated that the dAVF was fed by the radicular artery, sharing shunt point at the T10 level, and was drained by the radicular vein. The shunt point and drainer were well visualized by IA-ICG angiography, and direct occlusion of the shunt flow was successfully completed. We discuss the benefit of selective IA-ICG angiography for cerebrospinal vascular surgery in a neurosurgical hybrid operating suite.

Background: Retrieving elderly (≧75 y) patients with subarachnoid hemorrhage (SAH) from frailty is very important. We established a systematic protocol for achieving this purpose: coiling under local anesthesia, acute phase radical aneurysm treatment, prohibition of prophylactic cerebrospinal fluid drainage, and ambulation from the next day after a surgery. We reviewed our treatment outcomes.

Methods: From January 2005 to April 2016, 85 patients (11 male and 74 female) who underwent radical aneurysm treatment (28 coiling and 57 clipping) of 116 consecutive patients with SAH were analyzed. Patients with preoperative modified Rankin scale (m-RS) scores 1-3 and Hunt-Kosnik (HK) grades 1-3 were candidates for radical aneurysm treatment. Treatment methods (coiling or clipping) were decided after discussions with a certificated neurosurgeon and interventional surgeon. We defined m-RS 0-2 as independent state. In follow-ups of one month and longer (>3 months) after the onset of SAH, m-RS scores were determined. Statistical analysis was performed to distinguish factors that influence independent living.

Results: The median age was 78 years (range 75-89), and HK grades 1-3 were observed in 83%. Ratios of premorbid conditions or posterior circulation aneurysms were significantly larger in the coiling group; ratios of early ambulation or middle cerebral artery aneurysms were significantly larger in the clipping group. Independent state 1 month after the SAH was observed in 39% in the coiling group and in 35% in the clipping group; at 3 months, independent state was observed in 46% in the coiling group and in 35% in the clipping group. Multivariate analysis for independent state revealed the absence of pre-morbid condition, early ambulation, and absence of postoperative complications in the coiling group, and HK grade, early ambulation, and the absence of postoperative complications in the clipping group.

Conclusions: Our protocol is useful and effective. In elderly patients with SAH, early ambulation and avoiding postoperative complications after radical aneurysm treatment positively influence retrieval from frailty.

Guidelines in western countries for the management of carotid artery stenosis (CS) were formulated on the basis of the results of several randomized clinical trials (RCTs) in which risks of future ischemic events were estimated only based on luminal narrowing. Consequently, carotid endarterectomy (CEA) for symptomatic low-grade stenosis (LS) is not recommended and that for near occlusion (NO), which is a severe form of CS, is controversial because of the favorable outcomes of the medical treatments for LS and NO in the past RCTs. Luminal narrowing, however, does not necessarily reflect a significant burden of atherosclerotic plaque. Accumulating evidence from recent vascular biology studies and the advent of vessel wall imaging modalities, such as high-resolution magnetic resonance imaging (MRI), have indicated that plaque characteristics play pivotal roles in ischemic events.

We report the therapeutic outcomes of CEA for LS and NO based on carotid MRI plaque characterization to assess its safety and efficacy. The study participants were comprised of 17 patients with LS and 11 with NO among 101 consecutive patients who underwent CEA by the same surgeon (K.Y.). For the patients with LS, MRI plaque characteristics, histology of the excised plaque, safety of CEA, and long-term outcome were retrospectively studied. For patients with NO, long-term patency of the distal carotid artery was also analyzed.

The mean percentage of luminal stenosis was 31.6% ± 9.8%, and the MRI-detected intraplaque hemorrhage (IPH) and expansive remodeling (ER) were severe in the patients with LS. Histological studies demonstrated hemorrhage in all 17 plaques, ruptured fibrous cap in 15, and erosion with thrombosis in 2. The safety and long-term outcome of CEA with 57 months of follow-up were acceptable. In the patients with NO, CEA was performed without major adverse events in all the cases. Of the 5 patients with NO with full collapse, 3 who had an MRI-detected IPH demonstrated satisfactory patency of the distal internal carotid artery. Among the 2 patients without IPH, one had a collapsed distal ICA and the other showed an asymptomatic thrombotic occlusion.

In addition to the percentage of luminal stenosis, plaque evaluation based on MRI-detected IPH and ER could be helpful for improving the management of CS by offering a more precise risk stratification for future ischemic events or efficacy prediction of CEA in patients with CS.

Stroke is a cause of disability, which results from tetraparesis or hemiparesis in the extremities. Spastic hypertonia can have a profound effect on stroke recovery. In addition to its negative effects on gait, spastic hypertonia is often accompanied by other troubling upper motor neuron signs, such as painful spasm, weakness, and incoordination.

Intrathecal baclofen therapy (ITB) is effective and safe for treating spastic hypertonia resulting from cerebral palsy, spinal cord injury, brain injury, and multiple sclerosis. By circumventing the blood-brain barrier, only a small dose of baclofen is required via the intrathecal route of administration to exert its effects on spinal neurons. Baclofen, 4-amino-3 (p-chlorophenyl) butyric acid, is structurally similar to gamma aminobutyric acid (GABA) and binds to presynaptic GABA-B receptors within the brain stem, dorsal horn of the spinal cord, and other central nervous system (CNS) regions. The delivery system consists of a subcutaneously placed pump with a reservoir attached to an intraspinal catheter. The pump can be programmed to deliver medication at various flow rates through a catheter that enters at the lumbar spinal level into the subarachnoid space of the spinal canal. The central side effects of oral baclofen, such as drowsiness or confusion appear to be minimized with intrathecal administration.

Recently, ITB therapy is also being used for poststroke spastic hypertonia. We evaluated the usefulness of ITB therapy for spasticity in post-stroke patients.

Introduction: There are several factors to be considered in the treatment strategy for a ruptured internal carotid artery C2 segment aneurysm (IC-C2 AN), such as the morphology, size, and projecting direction of the AN. We report a case of successful treatment of a ruptured IC-C2 AN using neckplasty and clipping followed by coiling. We also discuss the possible treatment strategies for complicated cases of IC-C2 AN rupture in facilities without a hybrid operating room (OR).

Case presentation: A 62-year-old woman was admitted to our hospital with complaints of headache and vomiting. Her Glasgow Coma Scale score was 14 points (E3V5M6), and she had no other neurological deficits. Computed tomography (CT) revealed subarachnoid hemorrhage (SAH), and three-dimensional CT angiography (CTA) revealed a ruptured left IC-C2 AN. The neck width and length of the AN were 5.1 and 7.5 mm, respectively. We initially attempted treatment by clipping. However, complete clipping seemed extremely difficult. Therefore, we subsequently decided to perform neckplasty, followed by coiling. The postoperative CT scan revealed no newly developed high-density area (HDA) or low-density area (LDA). The patient underwent a ventriculoperitoneal (VP) shunt placement for hydrocephalus and was discharged 60 days after admission without neurological deficits.

Discussion: With regard to the optimal treatment of IC-C2 AN, the choice between coiling and clipping often remains controversial, and the combined strategy of coiling and clipping for IC AN has rarely been reported. In the present case, the AN had a broad neck, thereby making treatment with simple or balloon-assisted coiling difficult. As stent-assisted coiling for acute ruptured AN is currently off-label, we first used clipping owing to its technical reliability. During the operation, however, we judged that safe completion of the clipping was difficult and opted for neckplasty with a clip, followed by coiling, as our treatment strategy. In facilities where hybrid OR is unavailable, like ours, blind clipping is risky; hence, some other optimal treatment strategy should always be sought.

Conclusion: We report a case of IC-C2 AN rupture treated successfully with neckplasty with clipping and subsequent coiling.

In many cases with basilar top aneurysm, we recommend the anterior temporal approach, that combines the beneficial features of the pterional and subtemporal approach. However, in cases of aneurysms that are higher than 1 cm from the interclinoid line, large in size, or show posterior projection, the orbitozygomatic approach is more suitable. Each approach has been used properly depending on the height, size, or projection of the aneurysm. Not only the aneurysmal situation but also the surrounding vascular structure is clinically important as the retrocarotid space is restricted by the severely calcified or laterally deviated internal carotid artery and/or middle cerebral artery. Therefore, we should preoperatively pay attention to the anatomical vascular structures around the basilar top aneurysm even if the aneurysm itself can be easily approached.

Occasionally, no branch of the superficial temporal artery (STA) is available for extracranial-to-intracranial bypass (EC-IC bypass) surgery in the territory of the middle cerebral artery (MCA). The posterior auricular artery (PAA) mainly supplies the auricle and postauricular skin. The PAA is often emphasized as the feeding artery of a pedicle skin flap in reconstruction surgery around the auricle. Only five cases have been described in three reports of PAA-MCA bypass in the literature. We report three cases of EC-IC bypass using the PAA for MCA occlusion. The parietal branch of the STA was absent in two cases, and the other branches of the STA had been sacrificed during a previous operation in one case. The PAA had become larger than usual and extended to the parietal scalp in all cases. Two patients underwent double anastomosis of the frontal branch of the STA-MCA and PAA-MCA, and one patient was treated with single anastomosis involving the PAA-MCA. We made separate question mark-shaped, linear, and Y-shaped skin incisions. The bypass remained patent in all the cases. The PAA has a complementary role to those of the STA and occipital artery in the blood supply of the parietotemporal scalp. Presumably, when the STA branch is absent or has already been sacrificed or used, the PAA occasionally extends to the parietal scalp, maintaining an adequate caliber of the vessel. We suggest that the PAA is a potential alternative to the STA as a donor artery in EC-IC bypass. Selection of the proper operative method in PAA-MCA bypass is mandatory.