Single-Center Case Series of Simple Proximal Clipping for Large Thrombosed Vertebral Artery Aneurysms: Preservation of Perforating Arteries and Long-Term Outcomes.

BACKGROUND: Surgical proximal parent artery occlusion (PAO) is one of the treatments for partially thrombosed vertebral artery aneurysms (PTVAs). However, whether long-term changes in size and perforating arteries through the blind end can be truly preserved remain unknown. OBJECTIVE: To evaluate the efficacy and safety of surgical proximal PAO for PTVAs, focusing on the transition in size and preservation of perforating arteries. METHODS: We retrospectively reviewed 14 consecutive cases of unruptured large PTVAs. The cases were treated with surgical proximal PAO without trapping or thrombectomy. Preservation of the perforating arteries was confirmed through intraoperative indocyanine green video angiography. The aneurysm size was evaluated by measuring the maximum diameter on axial T2-weighted magnetic resonance images. Post-treatment outcomes were assessed using the modified Rankin Scale at the last follow-up examination. RESULTS: Thirteen patients (excluding 1 with morbidity) had a mean follow-up time of 33.2 months (range, 12-60 months) and a mean reduction rate of 71% (range, 32%-95%). Only 1 patient (7.2%) experienced postoperative stroke, and 13 patients (92.8%) showed no worsening of the modified Rankin Scale score at the final follow-up examination. The symptoms were improved in 5 of the 6 symptomatic patients (83.3%). In 10 patients (71.4%), a perforating branch that could not be identified on preoperative imaging was identified intraoperatively. CONCLUSION: Surgical proximal PAO without trapping or thrombectomy for PTVAs allows long-term reduction of aneurysm size and improves treatment safety by preserving the perforating artery, especially in cases wherein direct reconstruction is not feasible.

Intraoperative epileptogenic network visualization using gamma oscillation regularity correlation analysis in epilepsy surgery.

BACKGROUND: We have recently demonstrated that gamma oscillation (30-70 Hz) regularity (GOR) analysis accurately localized epileptogenic focus using intraoperative electrocorticographic data. In this report, we assessed whether GOR correlation analysis could depict epileptogenic networks intraoperatively. Dual foci in temporal lobe epilepsy without hippocampal structural abnormalities are difficult to diagnose. Using our GOR correlation analysis, we aimed to intraoperatively visualize such dual foci and epileptogenic networks. CASE DESCRIPTION: A 56-year-old man suffered from pharmacoresistant focal impaired awareness seizures. Magnetic resonance imaging demonstrated an 8 × 12-mm cavernoma in the right inferior temporal gyrus without any structural changes in the hippocampus. Since ictal semiology indicated a high probability of epileptogenicity in the right hippocampus, we reached the hippocampus using a transsylvian approach and assessed intraoperative GOR correlation analysis in the lateral temporal lobe where the cavernoma was located and the hippocampus, simultaneously. High GORs suggestive of epileptogenicity were identified in both the lateral temporal lobe and the hippocampus. Furthermore, they were connected using GOR correlation networks. When the high GOR locations in the lateral temporal lobe and the cavernoma were removed, high GORs and those networks were found within the hippocampus only. After additional hippocampal transection, high GORs and these networks were absent. The patient became seizure-free after the surgery. CONCLUSION: Our GOR correlation analysis may be a powerful tool for intraoperative evaluation of epileptogenic networks in epilepsy surgery.

Epileptogenic zone localization using intraoperative gamma oscillation regularity analysis in epilepsy surgery for cavernomas: patient series.

BACKGROUND: In epilepsy surgery for cavernoma with intractable focal epilepsy, removal of the cavernoma with its surrounding hemosiderin deposition and other extended epileptogenic zone has been shown to improve postsurgical seizures. However, there has been no significant association between such an epileptogenic zone and intraoperative electrocorticography (ECoG) findings. The authors recently demonstrated that high regular gamma oscillation (30-70 Hz) regularity (GOR) significantly correlates with epileptogenicity. OBSERVATIONS: The authors evaluated the utility of intraoperative GOR analysis in epilepsy surgery for cavernomas. The authors also analyzed intraoperative ECoG data from 6 patients with cavernomas. The GOR was calculated using a sample entropy algorithm. In 4 patients, the GOR was significantly high in the area with the pathological hemosiderin deposition. In 2 patients with temporal cavernoma, the GOR was significantly high in both the hippocampus and the area with the pathological hemosiderin deposition. ECoG showed no obvious epileptic waveforms in 3 patients, whereas extensive spikes were observed in 3 patients. All patients underwent cavernoma removal plus resection of the area with significantly high GOR. The 2 patients with temporal cavernomas underwent additional hippocampal transection. All patients were seizure free after surgery. LESSONS: The high GOR may be a novel intraoperative marker of the epileptogenic zone in epilepsy surgery for cavernomas.

Surgical clip occlusion of the V3 segment to prevent recurrent cerebral infarction associated with extracranial vertebral artery dissection: A case report.

BACKGROUND: Recurrent cerebral infarction caused by traumatic extracranial vertebral artery dissection (EVAD) is treated medically and surgically. We report a case of EVAD that was treated using surgical clip occlusion of the V3 segment to prevent recurrent cerebral infarction. CASE DESCRIPTION: A 48-year-old man was admitted for a cerebral infarction caused by EVAD and was treated using 200 mg/day cilostazol. Afterward, the cerebral infarction recurred. Digital subtraction angiography revealed that initial severe stenosis of the VA ostium resulted in the final occlusion and that collateral vessels to the VA remained. We continued antiplatelet therapy, but the cerebral infarction recurred due to thromboembolism of the collateral vessels. Parent artery occlusion was planned. We exposed the V3 segment of the VA and clipped it to prevent the recurrence of cerebral infarction. CONCLUSION: Surgical clip occlusion of the V3 segment was effective for treating recurrent cerebral infarction caused by traumatic EVAD that had remained an issue despite continuing medical therapy.

Whole-Field Indocyanine Green Intensity Analysis to Intraoperatively Predict Cerebral Hyperperfusion Syndrome Following Superficial Temporal Artery-Middle Cerebral Artery Bypass: A Retrospective Case-Control Study in 7-Year Experience With 112 Cases.

BACKGROUND: Intraoperative prediction of postoperative cerebral hyperperfusion syndrome (CHS) after cerebrovascular bypass surgery is challenging. OBJECTIVE: To conduct a retrospective case-control study with indocyanine green (ICG) intensity analysis of the superficial temporal artery-middle cerebral artery (STA-MCA) bypass and investigate whether its washout pattern might be a marker for intraoperative prediction of CHS. METHODS: Between 2012 and 2018, 6 of 112 patients (5.4%) that underwent STA-MCA bypass exhibited CHS. We selected 5 patients with CHS (3 with atherosclerotic cerebrovascular disease [ASCVD] and 2 with moyamoya) and 15 patients without CHS (60% ASCVD and 40% moyamoya) as a matched control group. During prebypass and postbypass, washout times (WTs) for the first 10%, 25%, 50%, and 75% of maximum ICG intensity measured in the whole-camera field were compared between groups. The changes in WT (ΔWT) from prebypass to postbypass for each ICG intensity level were compared between groups. The cutoff ΔWTs, sensitivities, and specificities were also calculated. RESULTS: Postbypass WTs were significantly longer in the CHS group than the control group at all ICG intensities (P < .05). ΔWT was significantly greater in the CHS group than the control group for the first 10%, 25%, and 50% ICG intensities (P < .001). A cutoff ΔWT of ≥2.66 s for the first 50% ICG intensity showed a sensitivity of 100% and specificity of 100%. CONCLUSION: We found that a ΔWT ≥2.66 s for the first 50% ICG intensity could be an intraoperative predictive factor for CHS.

An Experimental Clamping and Cutting Study of Carotid and Intracranial Stents: Preparation for Surgical Rescue in Stent Complications.

OBJECTIVE: To carry out surgery safely in vessels with stents, it is essential to have knowledge of what would happen if the stents were clamped or cut. Using all stents that are permitted in Japan, we recorded with a surgical microscope the behavior of stents when they were clamped or cut and discussed the morphologic changes along with image findings. METHODS: We classified carotid artery and intracranial stents as group 1A and 1B or group 2A and 2B according to the structure of stent eye: laser cut or blade. Each stent was clamped using a Yasargil aneurysm clip, bulldog forceps, and vascular forceps. Degree of closure and presence or absence of stent deformation after declamping were recorded using a surgical microscope. Furthermore, we performed morphologic evaluations using high-resolution cone-beam computed tomography. Lastly, each stent was cut; the behavior of the cut stent was recorded, and differences between stents were examined. RESULTS: Complete clamping was confirmed both visually and based on image evaluations with bulldog forceps and vascular forceps in the groups of carotid artery stents, with the Yasargil aneurysm clip in the intracranial stents. In the blade-type stents, we found that the stents elongated during clamping, and the component wire scattered at the time of stent cutting. Furthermore, the stents could be easily separated by holding with forceps. CONCLUSIONS: Knowing the properties of each stent is essential to conduct safe surgery in response to complications. Special care must be taken when clamping and cutting blade-type stents.

Intraoperative Micro-Measurement in Neurosurgical Microsurgery: A Technical Note.

OBJECTIVE: In neurosurgical microsurgery, understanding the accurate size of microstructures is essential to perform operation safely and less invasively. We here describe a simple method of measuring the size of microvessels using a digital image as a microscale. MATERIALS AND METHODS: The digital image was made as a microscale on the computer. We measured the size of intracranial microstructures using the microscale. RESULTS: We accurately measured the size of the vertebral artery perforator of 1 mm or less using the adjusted microscale on the computer. CONCLUSIONS: The development of a microscale is easy and renders the measurement of microstructures, sized 1 mm or less, feasible, and accurate.

Inhibitory Effects of Prolonged Vibratory Stimulus on the Maximal Voluntary Contraction Force and Muscle Activity of the Triceps Brachii: An Experimental Study.

OBJECTIVE: The purpose of this study was to quantify the effects of prolonged vibratory stimulus on the maximal voluntary contraction (MVC) force and muscle activity of the triceps brachii and to clarify the effective stimulus time. METHODS: Twenty-five healthy volunteers with a mean age of 21.4 years participated. A vibratory stimulus at 86 Hz was applied to the triceps brachii tendon for 5 and 10 minutes. Before and after these stimuli, the elbow extension MVC force was measured using a handheld dynamometer. Muscle activities of the lateral, long, and medial heads of the triceps brachii were also recorded by surface electromyography. RESULTS: The median MVC force significantly decreased to 82.7% after 5 minutes of vibratory stimulus and to 83.3% after 10 minutes of vibratory stimulus (P < .001). The median percentage of integrated electromyography of the triceps also significantly decreased to 78.2 (lateral head), 83.8 (long head), and 81.5 (medial head) after 5 minutes of vibratory stimulus and to 77.7, 81.4, and 77.2, respectively, after 10 minutes of vibratory stimulus (P < .001). There were no differences in the decrease in the MVC force and median percentage of integrated electromyography between 5 and 10 minutes of vibratory stimulus (P > .05). CONCLUSION: Prolonged vibratory stimulus (5 minutes) to the triceps brachii tendon appeared to have an inhibitory effect on MVC force and muscle activity. The present results suggest that prolonged vibratory stimulus could be an effective treatment capable of reducing muscle tonus of the triceps brachii.

Distance Between the Falciform Ligament and Distal Dural Ring as a Surgical Landmark for the Treatment of Paraclinoid Aneurysms.

OBJECTIVE: It is difficult to completely comprehend the anatomy of the structures surrounding the paraclinoid region before aneurysm and tumor treatment therein. When treating paraclinoid aneurysms, it is important to determine the location of the aneurysm as intradural or extradural. Thus, accurate prediction of the position of the distal dural ring (DDR) is necessary. To this end, we focused on the falciform ligament (FL), which is easily visualized on images based on its anatomic features. We measured the distance between the FL and the DDR in patients undergoing paraclinoid aneurysm operations. METHODS: Between January 2017 and July 2018, 15 patients who underwent clipping for paraclinoid aneurysm treatment were retrospectively identified. The distance between the FL and the DDR was measured using a microscale at the time of the operation. RESULTS: The patients comprised 14 women and 1 man. The mean aneurysm diameter was 7.29 ± 2.21 mm and the median size was 6.5 mm. Eleven of the aneurysms were on the left and 4 were on the right side. The mean distance between the FL and the DDR was 3.50 ± 0.17 mm and the median distance was 3.50 mm. The distance between the FL and the DDR was almost the same across cases (3.5 mm). CONCLUSIONS: The position of the FL can be easily predicted using preoperative three-dimensional computed tomography angiography based on its anatomic features. In this study, the DDR was located 3.5 mm proximal to the FL along the internal carotid artery. This information is useful for predicting the position of the DDR.

Is surgical parent artery occlusion effective for intracranial aneurysms measuring over 10 mm in size? Result from long-term follow-up of size changes and outcomes.

BACKGROUND: There have been no long-term follow-up reports pertaining to chronological size changes in large or giant unruptured intracranial aneurysms treated with surgical parent artery occlusion (PAO). The object of this study is to investigate the utility and safety of surgical PAO by conducting a long-term follow-up of chronological aneurysm size changes and outcomes. METHODS: A retrospective study of 21 unruptured intracranial aneurysms measuring over 10 mm (20 patients) treated with surgical PAO in the period 2012-2017 was conducted. For aneurysms presenting with anterior circulation, high/low flow bypass was chosen and carried out concomitantly on the basis of preoperative balloon occlusion test results. Aneurysm size before and after surgery was evaluated chronologically using maximum diameter measurements taken from the same slice of MRI T2-weighted images. Moreover, post-surgery outcomes were evaluated according to a modified Rankin scale (mRS) at discharge. RESULTS: PAO aiming for blind-alley formation was performed in 20 of 21 aneurysms (95.2%). Aneurysm size reduction was confirmed in 20 aneurysms (95.2%) after proper PAO, with an average reduction rate of 63.1% (range, 28-95%), during an average follow-up period of 27 months (range, 4-54 months). Eighteen (90.4%) of the 20 patients with 21 aneurysms returned to previous life with mRS score 0-2. With regard to preoperative symptoms, diplopia and visual impairment had improved in three patients (50%) and one patient (100%), respectively. Ischemic complications had occurred in five patients, two (9.6%) of whom were symptomatic and three (14.3%) were asymptomatic. The mortality rate in this study was 0%. CONCLUSIONS: Surgical PAO for unruptured intracranial aneurysms measuring over 10 mm has been shown to be an effective method of treatment, eliciting a reduction in aneurysm size.

Supine No-Retractor Method in Microvascular Decompression for Hemifacial Spasm: Results of 100 Consecutive Operations.

Objectives In microvascular decompression (MVD) for hemifacial spasm (HFS), the patient is placed in the lateral or park-bench position that is complicated and uncomfortable for anesthesiologists, nurses, and even the patient. Careless retraction of the cerebellum by a spatula could be the major cause of surgical complications. In our method, a patient is laid supine avoiding the complicated positioning. The subfloccular approach from a small cranial window sited on the more lateral and basal side of the occipital cranium enables the surgeon to reach all the segments of the facial nerve root without a spatula. We introduce our surgical procedures in detail along with our excellent results. Methods A total of 100 consecutive patients experiencing primary HFS were operated on with MVD by a single surgeon in our institution from August 2012 to April 2014. Results Overall, 94 patients showed the complete disappearance or a satisfactory alleviation of HFS. De novo neurologic deficits were not encountered after surgery including hearing impairment. In 47 cases, multiple offending vessels were observed in multiple possible affected sites in addition to the root entry/exit zone. Conclusions We believe this approach is superior for the safe and precise decompression of any part of the facial nerve root.

Characteristics and prognostic value of acute catecholamine surge in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVES: The characteristics of serum catecholamine concentration at the hyper-acute phase of aneurysmal subarachnoid hemorrhage (SAH) and its relationship between patient outcome and delayed vasospasm were investigated. METHODS: Patients with aneurysmal SAH (170) were prospectively studied between August 2008 and June 2011. Baseline demographic data and physiological parameters, including plasma concentrations of adrenaline (AD), noradrenaline (NA), and dopamine (DP) were evaluated for all patients. RESULTS: On admission, plasma AD, NA, and DP levels were significantly higher in patients with a poor clinical grade on admission (Hunt and Kosnik grade: IV-V), compared to those with a good clinical grade on admission (Hunt and Kosnik grade: I-III). AD showed a markedly high concentration immediately after the onset of SAH and then rapidly decreased. NA levels peaked within 6 hours after onset, then significantly decreased. The increase of DP with time was not significant, but showed a similar trend to that of NA. The level of each catecholamine showed significant mutual correlation. Our multivariate model demonstrated that age, poor clinical grade at admission, plasma AD and NA levels were good predictors of poor patient outcome [receiver operating characteristic (ROC) area: 0.83]. And that poor clinical grade at admission, Fisher scale, blood sugar level and plasma AD level were good predictors of the development of delayed vasospasm (ROC area: 0.81) (1.3). CONCLUSIONS: The present findings suggest that sympathetic activation in patients in the acute phase of SAH reflects the severity of SAH, and is closely related to the development of delayed vasospasm, leading to the subsequent immune response and inflammatory reactions. Strategies for suppressing catecholamine at the hyper-acute phase may contribute to vasospasm prevention and improve patient outcome.

Prevention of symptomatic vasospasm by continuous cisternal irrigation with mock-CSF containing ascorbic acid and Mg(2+).

BACKGROUND: Symptomatic vasospasm (SVS) is still a major cause of poor outcome in cases undergoing early surgical intervention for ruptured intracranial aneurysm. Among the numbers of therapeutic trials to prevent and ameliorate neurological deterioration due to SVS, removal or quenching of oxy-hemoglobin (OxyHb) from subarachnoid colts and administration of Mg(2+) (Mg) have especially been expected to be effective. In this report the authors investigated the effect of continuous cisternal irrigation (CCI) with mock CSF containing ascorbic acid (ASA) and Mg, performed after early surgery for ruptured aneurysm. METHOD: Sixty-three cases which had received CCI were retrospectively compared with 40 control cases as to the incidence of SVS and outcome. FINDINGS: Incidence of SVS was significantly less frequent (P < 0.05) in the CCI group (11%) than in the control group (25%). Severe and definitive SVS requiring additional specific treatment occurred only in 3.2% of the CCI group, while 22.5% in the control (P < 0.01). Overall outcome at discharge was significantly better in the CCI group than in the control (P < 0.01). CONCLUSIONS: Postoperative CCI with ASA and Mg was definitively effective in preventing SVS and in lessening severity of SVS if it occurs.

Immunohistochemical analysis of the mutant epidermal growth factor, deltaEGFR, in glioblastoma.

The naturally occurring mutated form of the epidermal growth factor receptor, deltaEGFR (also named EGFRvIII and de2-7EGFR), greatly enhances glioblastoma (GBM) cell growth in vivo through several activities, such as down-regulating p27 and up-regulating BclX(L) while increasing signaling through the RAS-MAPK and PI3-K cascades. More than half of GBMs, especially of the de novo type, overexpress EGFR, and 50%-70% of these express deltaEGFR. However, little is known about the distribution of deltaEGFR-expressing tumor cells within surgical specimens. In order to address this clinically important issue, we performed immunohistochemical analyses of 53 GBMs obtained during surgery using the anti- deltaEGFR monoclonal antibody, DH8.3. We also simultaneously analyzed wild-type EGFR expression in these tissues using the anti-EGFR monoclonal antibody, EGFR.113. deltaEGFR and wild-type EGFR expression were observed in 20/53 (38%) and 29/53 (55%), respectively. Nineteen (95%) of the deltaEGFR-positive tumors also expressed wild-type EGFR; one case was deltaEGFR-positive but wild-type EGFR-negative. In 13/20 (65%) of the deltaEGFR-positive tumors, tumor cells were scattered diffusely within the tumors, 6/20 showed geographical distribution of deltaEGFR-positive tumor cells, and one case showed homogeneous staining. In the wild-type EGFR-positive cases, almost all tumor cells expressed EGFR. The differential distribution of cells expressing the two receptors observed here may suggest either that deltaEGFR arises at a low frequency from wild-type EGFR-expressing cells, perhaps during the process of gene amplification, or that there is a paracrine-type of interaction between them.

[Spontaneous epidural hematoma in a patient undergoing hemodialysis: a case report].

A 54-year-old male with chronic renal failure due to diabetic nephropathy suffered dysphagia and left facial spasm without head trauma during a hemodialysis session. CT scan revealed a right acute epidural hematoma. MRI and cerebral angiography did not reveal any abnormalities in the intracranial vasculature. The occurrence of intracranial spontaneous epidural hematoma in a haemodialysis patient has not been reported. During hemodialysis, the intracranial pressure transiently increases and rapidly recovers. It is assumed that the decreasing intracranial pressure caused epidural hematoma.

[A case of cervical pyogenic spondylitis difficult to differentiate from metastatic spinal tumor].

A 52-year-old man with medical complications of diabetic mellitus and alcoholic liver dysfunction, presented with weakness in the bilateral lower extremities. Cervical magnetic resonance images disclosed the lesion extended from retropharyngeal space and multiple vertebral bodies to epidural space of the spinal canal, which was enhanced by gadolinium. Not only fever elevation during clinical course but also inflammatory reaction on selologic examination were not identified, so we initially thought the lesion metastatic spinal tumor. In researching original foci, his clinical condition worsened with gate disturbance and urinary incontinence. Eleven days later after admission, laminectomy from C-5 to Th-1 and open biopsy of the lesion was performed. The vertebral bodies exposed via the right frontal approach were covered by thick whitish membrane. Small mount of pus emerged after incision of the membrane, so we diagnosed the lesion pyogenic spondylitis. After the operation, high dose antibiotic therapy for 6 weeks was performed. Follow-up cervical MR imaging 4 months after the operation found that the volume of the lesion and compression of the spinal cord were reduced. The gate disturbance and urinary incontinence gradually improved, he was able to walk with a cane 6 months later.