The Impact of Enteral Nimodipine on Endothelial Cell Apoptosis in an Animal Subarachnoid Hemorrhage Model.

BACKGROUND: Enteral nimodipine is the most evidence-based and widely used drug for the treatment of delayed cerebral ischemia and is known to have various neuroprotective functions. However, the neuroprotective mechanism of nimodipine still remains unclear, and the effects of nimodipine remain ambiguous. Herein, we studied the effect of enteral nimodipine on endothelial apoptosis after subarachnoid hemorrhage (SAH). METHODS: SAH was experimentally introduced in white rabbits (n = 42) that were grouped as follows: enteral nimodipine (SAH-nimodipine group, n = 14), a control that received normal saline (SAH-saline group, n = 13), and a control without hemorrhage (control group, n = 15). On the third day after SAH induction, the brain stem, including the vertebrobasilar vascular system, was extracted. The effects of enteral nimodipine were analyzed by group using histopathologic analysis, including immunohistochemical staining of apoptosis-related proteins (Bcl2 [anti-apoptotic] and Bax [pro-apoptotic]). RESULTS: Cytoplasmic vacuolation of smooth muscle cells was observed in two SAH hemorrhagic groups and was more prominent in the SAH-saline group. Endothelial desquamation was observed only in the SAH-saline group. For the basilar artery, expression of Bcl2 and Bax in the SAH-nimodipine group was lower than that in the SAH-saline group, but significant differences were not observed (pBcl2 = 0.311 and pBax = 0.720, respectively). In penetrated arterioles, the expression of Bax in the SAH-nimodipine group was significantly lower than that of the SAH-saline group (p < 0.001). The thickness of the tunica media in the basilar artery was thinner in the SAH-nimodipine group than in the SAH-saline group (p < 0.001). CONCLUSIONS: This study suggests that enteral nimodipine may have a neuroprotective function by inhibiting endothelial apoptosis in small arterioles and preventing smooth muscle cell proliferation in large arteries.

Clinical Outcomes of Clipping and Coil Embolization for Ruptured Intracranial Aneurysms Categorized by Region and Hospital Size: A Nationwide Cohort Study in Korea.

BACKGROUND: To analyze the outcomes of clipping and coiling for ruptured intracranial aneurysms (RIAs) based on data from the National Health Insurance Service in South Korea, with a focus on variations according to region and hospital size. METHODS: This study analyzed the one-year mortality rates for patients with RIAs who underwent clipping or coiling in 2018. Coiling was further categorized into non-stent assisted coiling (NSAC) and stent assisted coiling (SAC). Hospitals were classified as tertiary referral general hospitals (TRGHs), general hospitals (GHs), or semi-general hospitals (sGHs) based on size. South Korea's administrative districts were divided into 15 regions for analysis. RESULTS: In 2018, there were 2,194 (33.1%) clipping procedures (TRGH, 985; GH, 827; sGH, 382) and 4,431 (66.9%) coiling procedures (TRGH, 1,642; GH, 2076; sGH, 713) performed for RIAs treatment. Among hospitals performing more than 20 treatments, the one-year mortality rates following clipping or coiling were 11.2% and 16.0%, respectively, with no significant difference observed. However, there was a significant difference in one-year mortality between NSAC and SAC (14.3% vs. 19.5%, P = 0.034), with clipping also showing significantly lower mortality compared to SAC (P = 0.019). No significant differences in other treatment modalities were observed according to hospital size, but clipping at TRGHs had significantly lower mortality than at GHs (P = 0.042). While no significant correlation was found between the number of treatments and outcomes at GHs, at TRGHs, a higher volume of clipping procedures was significantly associated with lower total mortality (P = 0.023) and mortality after clipping (P = 0.022). CONCLUSION: Using Korea NHIS data, mortality rates for RIAs showed no significant variation by hospital size due to coiling's prevalence. However, differences in clipping outcomes by hospital size and volume in TRGH highlight the need for national efforts to improve clipping skills and standardization. Additionally, the higher mortality rate with SAC emphasizes the importance of precise indications for its application.

Clinical Outcomes of Clipping and Coiling in Elderly Patients with Unruptured Cerebral Aneurysms: a National Cohort Study in Korea.

BACKGROUND: We aimed to analyze outcomes of clipping and coiling in treating unruptured intracranial aneurysms (UIAs) in elderly patients and to identify the age at which perioperative risk increases based on national cohort data in South Korea. METHODS: The incidence of perioperative intracranial hemorrhage (ICRH), perioperative cerebral infarction (CI), mortality, and moderate to severe disability data of the patients who underwent coiling or clipping for UIAs were retrieved. Estimated breakpoint (EBP) was calculated to identify the age at which the risk of treatment increases. RESULTS: A total of 38,207 patients were treated for UIAs. Among these, 22,093 (57.8%) patients underwent coiling and 16,114 (42.2%) patients underwent clipping. The incidence of ICRH, requiring a secondary operation, within 3 months in patients ≥ 65 years that underwent coiling and clipping was 1.13% and 4.81%, respectively, and that of both groups assessed were significantly higher in patients ≥ 75 years (coiling, P = 0.013, relative risk (RR) 1.81; clipping, P = 0.015) than younger patients. The incidence of CI within 3 months in patients aged ≥ 65 was 13.90% and 9.19% in the coiling and clipping groups, respectively. The incidence of CI after coiling in patients aged ≥ 75 years (P < 0.001, RR 1.96) and after clipping in patients aged ≥ 70 years (P < 0.001, RR 1.76) was significantly higher than that in younger patients. The mortality rates within 1 year in patients with perioperative ICRH or CI were 2.41% and 3.39% for coiling and clipping groups, respectively, in patients ≥ 65. These rates increased significantly at age 70 in the coiling group and at age 75 for the clipping group (P = 0.012 and P < 0.001, respectively). CONCLUSION: The risk of treatment increases with age, and this risk increases dramatically in patients aged ≥ 70 years. Therefore, the treatment decisions in patients aged ≥ 70 years should be made with utmost care.

Augmentation of Supratemporal Hollowing With Silicone Block During Autologous Cranioplasty After Decompressive Craniectomy With Additional Temporalis Resection.

ABSTRACT: Decompressive craniectomy is a potentially life-saving neurosurgical procedure. In cases of insufficient decompression, uncontrolled intracranial pressure even after sufficient decompression, or when the intracranial pressure is increased due to external factors such as intramuscular hematoma in the temporal muscle, additional temporalis resection may be necessary. However, the hollowing of the supratemporal fossa that occurs after additional temporalis resection can create a major cosmetic problem. Several alternatives are available to fill the hollowing of the supratemporal fossa during cranial reconstruction, but each has a disadvantage, whether it is expensive or difficult to shape for bilateral symmetry. The author solved the cosmetic problem by using a properly carved silicone block to fill the supratemporal fossa while conducting cranioplasty, and here reports it with a literature review.

Simultaneous neck coverage and branch preservation using the proximal portion of a self-expandable open-cell stent for embolization of distal internal carotid artery aneurysms: multi-center, long-term results.

PURPOSE: We report the long-term results of a modified stent-assisted coil embolization technique using the far proximal part of a self-expanding open-cell stent. The technique was used to cover the neck of the aneurysm while simultaneously preserving the branches of the distal internal carotid artery in patients with aneurysms of the posterior communicating (Pcom) and anterior choroidal arteries (AchA). METHODS: We performed a retrospective review of the prospectively maintained databases at two tertiary neurosurgical centers to identify all patients who underwent embolization of Pcom or AchA aneurysms using this technique between January 2014 and July 2019. Postoperative and follow-up clinical and radiological results for initial (n = 16) or re-do (n = 4) embolizations were analyzed. RESULTS: We identified 19 patients with 20 (16 Pcom and 4 AchA) unruptured (n = 19) or ruptured (n = 1) aneurysms. Eighteen among 20 stents (90.0%) were deployed successfully, and complete occlusions were initially attained in 18 aneurysms (90.0%). At follow-up examinations 8 to 56 months later, 6 of 14 aneurysms (42.8%) showed neck remnants. All of the branches were saved and no thromboembolic event, rupture, or sequelae were noted during or after the procedures. CONCLUSION: These results suggest that this modified stent-assisted technique is a feasible and reasonable alternative to conventional stent deployment for coil embolization of wide-necked sidewall aneurysms in the distal ICA.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma.

Purpose To evaluate the effect of middle meningeal artery (MMA) embolization on chronic subdural hematoma (CSDH) and compare the treatment outcomes of MMA embolization and conventional treatment. Materials and Methods All consecutive patients 20 years or older with CSDH were assessed for eligibility. CSDHs with a focal location, a thickness of 10 mm or less, no mass effect, or underlying conditions were excluded. Seventy-two prospectively enrolled patients with CSDH underwent MMA embolization (embolization group; as the sole treatment in 27 [37.5%] asymptomatic patients and with additional hematoma removal for symptom relief in 45 [62.5%] symptomatic patients). For comparison, 469 patients who underwent conventional treatment were included as a historical control group (conventional treatment group; close, nonsurgical follow-up in 67 [14.3%] and hematoma removal in 402 [85.7%] patients). Primary outcome was treatment failure defined as a composite of incomplete hematoma resolution (remaining or reaccumulated hematoma with thickness > 10 mm) or surgical rescue (hematoma removal for relief of symptoms that developed with continuous growth of initial or reaccumulated hematoma). Secondary outcomes included surgical rescue as a component of the primary outcome and treatment-related complication for safety measure. Six-month outcomes were compared between the study groups with logistic regression analysis. Results Spontaneous hematoma resolution was achieved in all of 27 asymptomatic patients undergoing embolization without direct hematoma removal. Hematoma reaccumulation occurred in one (2.2%) of 45 symptomatic patients receiving embolization with additional hematoma removal. Treatment failure rate in the embolization group was lower than in the conventional treatment group (one of 72 patients [1.4%] vs 129 of 469 patients [27.5%], respectively; adjusted odds ratio [OR], 0.056; 95% confidence interval [CI]: 0.011, 0.286; P = .001). Surgical rescue was less frequent in the embolization group (one of 72 patients [1.4%] vs 88 of 469 patients [18.8%]; adjusted OR, 0.094; 95% CI: 0.018, 0.488; P = .005). Treatment-related complication rate was not different between the two groups (0 of 72 patients vs 20 of 469 patients [4.3%]; adjusted OR, 0.145; 95% CI: 0.009, 2.469; P = .182). Conclusion MMA embolization has a positive therapeutic effect on CSDH and is more effective than conventional treatment. © RSNA, 2017.

Risk factor analysis of recanalization and retreatment for patients with endovascular treatment of internal carotid artery bifurcation aneurysms.

PURPOSE: Only a few reports of internal carotid artery (ICA) bifurcation aneurysms using the endovascular technique have been published in the current literature. The purpose of this study was to assess how multiple risk factors including angioarchitectural features of ICA bifurcation characteristics may have influenced aneurysmal rupture, recanalization, and retreatment. METHODS: Fifty-one patients with 52 ICA bifurcation aneurysms treated with endovascular coiling between July 2003 and July 2015 were retrospectively analyzed. The patients' clinical records, endovascular reports, and clinical and angiographic outcomes were reviewed. We also evaluated risk factors for recanalization and retreatment, including the angioarchitectural anatomy. RESULTS: The clinical outcomes were observed to be satisfactory in 49 patients (96.0%) and unfavorable in 2 patients (4.0%). The risk factor for aneurysmal rupture was young age (P = 0.024). Symptomatic complications due to thromboembolism occurred in 1.9% of cases; no patients suffered a fatal complication. Eleven of 52 ICA bifurcation aneurysms (21.2%) were recanalized within an average of 54.3 ± 33.5 months of follow-up. Among the aneurysms, 4 (7.7%) underwent recoiling. Multivariate analysis showed that ruptured aneurysms (P = 0.006) and a lower packing density (P = 0.048) were risk factors for recanalization. A lower packing density was the only risk factor for retreatment (P = 0.019). CONCLUSION: Endovascular treatment of ICA bifurcation aneurysms is considered safe and acceptable. This study showed that the ICA bifurcation aneurysms ruptured more frequently at a younger age. A higher packing density has been shown to reduce major recanalization and retreatment.

Coil embolization of the middle cerebral artery bifurcation aneurysms: Feasibility and durability.

OBJECTIVE: To evaluate the feasibility and durability of coil embolization for MCAB aneurysms by analyzing clinical and radiological results. METHODS: From January of 2008 to June of 2018, we treated a total of 1785 aneurysms using coil embolization. The aneurysms were treated by both coiling and stent-assisted coiling. Among these cases, 223 MCAB aneurysms were analyzed retrospectively. Clinical and radiological assessments were conducted at admission, after treatment, at discharge, and at last clinical follow-up. RESULTS: Coil embolization was performed on 223 MCAB aneurysms in 217 patients. Peri-procedural ischemic, hemorrhagic, and other complications within 30 days after coil embolization occurred at rates of 8.0 %, 8.0 %, and 2.0 %, respectively, in the ruptured group and at 2.9 %, 1.2 %, and 0 %, respectively, in the unruptured group. The overall morbidity and mortality rates associated with complications were 2.3 % and 2.0 %. The cumulative major recurrence rates were 5.1 % at 12 months, 7.1 % at 18 months, and 11.9 % at three years after coil embolization. The mean follow-up period was 33.27 ± 25.48 months. Independent risk factors for major recurrence after coil embolization for MCAB aneurysms were a ruptured aneurysm, initial incomplete occlusion, the aneurysm size, and the neck size. CONCLUSION: Coil embolization is a good alternative treatment option for MCAB aneurysms compared to surgical clipping. Considering the risk factors for major recurrence, the follow-up angiography should continue up to three years after coil embolization.

Optimal blood pressure for stroke prevention in healthy adults below 65 years: A nationwide 10-year observational study.

BACKGROUND: There have been few reports on the preventative value of intensive blood pressure (BP) management for stroke since the American College of Cardiology/American Heart Association (ACC/AHA) announced the new criteria for hypertension (HTN) in 2017. This study aimed to identify optimal BP for prevention of stroke in healthy adults under 65 years. METHODS: We conducted a 10-year observational study on the risk of stroke, subclassified as hemorrhagic stroke (HS) or ischemic stroke (IS), according to BP categories (low-normal BP, high-normal BP, elevated BP, stage 1 HTN, and stage 2 HTN) using the National Health Insurance Service Database. RESULTS: In 2008, a health checkup was conducted for a total of 8,327,751 participants, and 949,551 of them enrolled in this study. The risk of HS increased from stage 2 HTN (adjusted hazard ratio [AHR], 3.036 [95 % confidence interval [CI], 2.159-4.252]) in men to stage 1 HTN (AHR, 2.972; 95 % CI, 2.256-3.897) in women. The risk of IS increased in both men (AHR, 1.404 [95 % CI, 1.164-1.693]) and women (AHR, 2.012 [95 % CI, 1.603-2.526]) with stage 1 HTN. The overall risk of stroke increased in men (AHR, 1.386; [95 % CI, 1.180-1.629]) and women (AHR, 2.363 [95 % CI, 1.973-2.830]) with stage 1 HTN. CONCLUSION: This study underscores the importance of maintaining BP below Stage 1 HTN to prevent stroke in healthy adults aged below 65 years. These findings highlight the significance of the new HTN guidelines established by the ACC/AHA in 2017.

Prediction of contralateral progression in patients with bilateral nonhemorrhagic moyamoya disease following unilateral revascularization surgery.

OBJECTIVE: This study was designed to identify predictive factors associated with substantial contralateral progression in adult patients with bilateral nonhemorrhagic moyamoya disease (MMD) who undergo revascularization surgery (RS) on one hemisphere. METHODS: The authors retrospectively analyzed 174 contralateral hemispheres of patients with bilateral nonhemorrhagic MMD (non-hMMD) who underwent RS on one side. The primary endpoint was defined as substantial contralateral progression requiring additional RS 6 months after the initial RS. The annual risk and predictive factors for contralateral progression were also analyzed. RESULTS: Of 174 patients included in the study, 57 (32.8%) experienced contralateral progression over a mean follow-up of 45.3 ± 31.6 months (range 12-196 months). The annual risk for contralateral progression after initial unilateral RS was 7.7% per person-year. Multivariable analysis revealed that age (HR 0.967, 95% CI 0.944-0.992; p = 0.009) and a BMI ≥ 25 (HR 1.946, 95% CI 1.126-3.362; p = 0.017) were significant predictors of contralateral progression. Specifically, the annual risk of contralateral progression was 12.1% in the higher BMI (≥ 25) group and 4.0% in the lower BMI (< 25) group per person-year. CONCLUSIONS: The study revealed a 7.7% per person-year rate of contralateral progression in patients with bilateral non-hMMD following unilateral RS. Younger age and a BMI ≥ 25 were identified as significant risk factors. For these patients, careful weight management and the use of antilipid agents may be crucial strategies for reducing the risk of contralateral progression after unilateral RS.

The Usefulness of Extradural Anterior Clinoidectomy for Lower-Lying Posterior Communicating Artery Aneurysms : A Cadaveric Study.

Objective: To confirm the usefulness of the extradural anterior clinoidectomy during the clipping of a lower riding posterior communicating artery (PCoA) aneurysm through cadaver dissection. Methods: Anatomic measurements of 12 adult cadaveric heads (24 sides total) were performed to compare the microsurgical exposure of the PCoA and internal carotid artery (ICA) before and after clinoidectomy. A standard pterional craniotomy and transsylvian approach were performed in all cadavers. The distance from the ICA bifurcation to the origin of PCoA (D1), pre-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D2), post-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D3), pre-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D4) and post-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D5) and the distance of the ICA obtained after anterior clinoidectomy (D6) were measured. We measured the precise thickness of the blade for the Yasargil clip with a digital precision ruler to confirm the usefulness of the extradural anterior clinoidectomy. Results: Twenty-four sites were dissected from 12 cadavers. The age of the cadavers was 79.83±6.25 years. The number of males was the same as the females. The space from the proximal origin of the PCoA to the preclinoid-tentorium (D4) was 1.45±1.08 mm (max: 4.01, min: 0.56). After the clinoidectomy, the space from the proximal origin of the PCoA to the postclinoid-tentorium (D5) was 3.612±1.15 mm (max: 6.14, min: 1.83). The length (D6) of the exposed proximal ICA after the extradural clinoididectomy was 2.17±1.04 mm on the lateral side and 2.16±0.89 mm on the medial side. The thickness of the Yasargil clip blade used during the clipping surgery was 1.35 mm measured with a digital precision ruler. Conclusion: The proximal length obtained by performing an external anterior clinoidectomy is about 2 mm, sufficient for proximal control during PCoA aneurysm surgery, considering the thickness of the aneurysm clips. In a subarachnoid hemorrhage, performing an extradural anterior clinoidectomy could prevent a devastating situation during PCoA aneurysm clipping.

Vasodilatory effects of tadalafil in an animal model of cerebral vasospasm: Comparative analysis with oral nimodipine.

OBJECTIVES: Cerebral vasospasm is one of the most fatal complications after spontaneous aneurysmal subarachnoid hemorrhage. Although various treatments have been tried for the treatment of cerebral vasospasm so far, the effect is insignificant or temporary except for oral nimodipine. Phosphodiesterase isozyme type 5 inhibitor, which is used to treat erection dysfunction, recently has been known to have a cerebrovascular vasodilation. It is thought that this will be effective in cerebral vasospasm, and the effect will be compared and analyzed with oral nimodipine through an animal model of cerebral vasospasm. MATERIAL AND METHODS: A total of 40 rabbits were used to make subarachnoid hemorrhage model and were divided into three groups - a control group, nimodipine group, and tadalafil group. The cerebral vessels were angiographically measured before and on the third day of subarachnoid hemorrhage. Then vertebrobasilar arteries were harvested and evaluated. Under the microscope, lumen area and media area were measured for each group and were compared. RESULTS: Angiographically, tadalafil group showed significant vasodilation compared with the control group (p < 0.01). Histologically, tadalafil showed a similar effect on lumen and on media area to that of nimodipine group compared with the control group. CONCLUSIONS: Cerebral vasospasm could leave neurologic deficit or sequelae even after proper treatment. Therefore, prevention is important. Tadalafil showed preventive effect against cerebral vasospasm and vasodilative effect similar to that of nimodipine. Therefore, tadalafil could be considered an alternative preventive treatment of cerebral vasospasm.

Cadaveric analysis of transcranial versus endoscopic transorbital petrosectomy: comparison of surgical maneuverability and brainstem exposure.

Introduction: While accessing the posterior fossa, the anterior transpetrosal approach (ATPA) and endoscopic transorbital approach (ETOA) use the same bony landmarks during petrous apex drilling. However, owing to their contrasting surgical axes, they are expected to show differences in surgical view, maneuverability, and clinical implications. This study aimed to investigate the feasibility of ETOA in accessing the brainstem and to compare the surgical view and maneuverability of each approach. Methods: ATPA and ETOA were performed in four human cadaveric heads (eight sides and four sides in each procedure). The angle of attack (AOA) and surgical depth were measured at the target of interest (root exit zone [REZ] of cranial nerve [CN] V, VI, and VII). When measuring the area of exposure, the brainstem was divided into two areas (anterior and lateral brainstem) based on the longitudinal line crossing the entry zone of the trigeminal root, and the area of each was measured. Results: ATPA showed significantly greater value at the trigeminal REZ in both vertical (31.8 ± 6.7° vs. 14.3 ± 5.3°, p=0.006) and horizontal AOA (48.5 ± 2.9° vs. 15.0 ± 5.2°, p<0.001) than ETOA. The AOA at facial REZ was also greater in ATPA than ETOA (vertical, 27.5 ± 3.9° vs. 8.3 ± 3.3°, p<0.001; horizontal, 33.8 ± 2.2° vs. 11.8 ± 2.9°, p<0.001). ATPA presented significantly shorter surgical depth (CN V, 5.8 ± 0.5 cm vs. 9.0 ± 0.8, p<0.001; CN VII, 6.3 ± 0.5 cm vs. 9.5 ± 1.0, p=0.001) than ETOA. The mean area of brainstem exposure did not differ between the two approaches. However, ATPA showed significantly better exposure of anterior brainstem than ETOA (240.7 ± 9.6 mm2 vs. 171.7 ± 15.0 mm2, p<0.001), while ETOA demonstrated better lateral brainstem exposure (174.2 ± 29.1 mm2 vs. 231.1 ± 13.6 mm2, p=0.022). Conclusions: ETOA could be a valid surgical option, in selected cases, that provides a direct ventral route to the brainstem. Compared with ATPA, ETOA showed less surgical maneuverability, AOA and longer surgical depth; however, it presented comparable brainstem exposure and better exposure of the lateral brainstem.

Clinical Outcomes of Coil Embolization for Unruptured Intracranial Aneurysms Categorized by Region and Hospital Size : A Nationwide Cohort Study in Korea.

OBJECTIVE: To analyze the outcomes of coil embolization (CE) for unruptured intracranial aneurysm (UIA) according to region and hospital size based on National Health Insurance Service data in South Korea. METHODS: The incidence of complications, including intracranial hemorrhage (ICRH) and cerebral infarction (CI), occurring within 3 months and the 1-year mortality rates in UIA patients who underwent CE in 2018 were analyzed. Hospitals were classified as tertiary referral general hospitals (TRGHs), general hospitals (GHs) or semigeneral hospitals (sGHs) according to their size, and the administrative districts of South Korea were divided into 15 regions. RESULTS: In 2018, 8425 (TRGHs, 4438; GHs, 3617; sGHs, 370) CEs were performed for UIAs. Complications occurred in 5.69% of patients seen at TRGHs, 13.48% at GHs, and 20.45% at sGHs. The complication rate in TRGHs was significantly lower than that in GHs (p=0.039) or sGHs (p=0.005), and that in GHs was significantly lower than that in sGHs (p=0.030). The mortality rates in TRGHs, GHs, and sGHs were 0.81%, 2.16%, and 3.92%, respectively, with no significant difference. Despite no significant difference in the mortality rates, the complication rate significantly increased as the number of CE procedures per hospital decreased (p=0.001; rho=-0.635). Among the hospitals where more than 30 CEs were performed for UIAs, the incidence of CIs (p=0.096, rho=-0.205) and the mortality rates (3 months, p=0.048, rho=-0.243; 1 year, p=0.009, rho=-0.315) significantly decreased as the number of CEs that were performed increased and no significant difference in the incidence of post-CE ICRH was observed. CONCLUSION: The complication rate in patients who underwent CE for UIA increased as the hospital size and physicians' experience in conducting CEs decreased. We recommend nationwide quality control policies CEs for UIAs.

Comparative Study of Vasodilatation After Intra-arterial Nicardipine or Dantrolene Infusion in Animal Model of Cerebral Vasospasm.

PURPOSE: Intra-arterial (IA) infusion of calcium channel blockers (CCBs) has been widely applied in treating medically refractory vasospasm; however, surprisingly little is known regarding their vasodilatory duration. This study was undertaken to compare attributes of nicardipine and dantrolene, focusing on efficacy and capacity for sustained vasodilation. METHODS: In New Zealand white rabbits (N = 22), vasospasm was individually provoked through experimentally induced subarachnoid hemorrhage and confirmed via conventional angiography, grouping animals by IA-infused drug (nicardipine vs. dantrolene). Controls received normal saline. After chemoangioplasty, follow-up angiography was performed at intervals of 1-3 h for 6 h to compare vasospastic and dilated (i.e., treated) arterial diameters. Drug efficacy, duration of action, and changes in mean arterial pressure (relative to baseline) were analyzed by group. RESULTS: Compared with controls, effective vasodilation was evident in both nicardipine and dantrolene test groups after IA infusion. Vasodilatory effects of nicardipine peaked at 1 h, returning to former vasospastic states at 3 h. In dantrolene recipients, vasodilation endured longer, lasting >6 h. Only the nicardipine group showed a significant 3­h period of lowered blood pressure. CONCLUSION: Unlike the vasodilatory action of a CCB, sustained for < 3 h after IA infusion, the effect of dantrolene endured for > 6 h. This outcome suggests that IA dantrolene infused alone or together with a conventional CCB infusion may be a new means of prolonging vasodilatory effect. Further research is needed to assess durations of IA-infused vasodilatory drug based on perfusion status.

Forced suction thrombectomy in patients with acute ischemic stroke using the SOFIA Plus device.

OBJECTIVE: Stent retrieval thrombectomy has recently been the standard treatment for acute ischemic stroke with large artery occlusion. However, the development of catheters for suction thrombectomy has recently led to results comparable to that of stent retrieval thrombectomy (SRT). This study aimed to analyze the safety and efficacy of forced suction thrombectomy (FST) using the SOFIA Plus (MicroVention Terumo, Tustin, CA, USA) device. METHODS: We included patients with acute ischemic stroke who underwent FST using the SOFIA Plus device at our institution. Medical records and angiographic data were reviewed, and the results of this study were compared with those of other FST studies. RESULTS: A total of 35 patients were included in this study. The occlusion sites were the internal carotid artery terminal (4), M1 segment (20), and posterior circulation (11). Of the 35 patients, FST was performed in only 21 (60%) patients, and the remaining 14 (40%) patients underwent SRT and FST. In all cases, the recanalization rate was 100%, and the average time from groin puncture to recanalization was 21±4.94 min. In particular, the average time required to reach the SOFIA Plus lesions from the groin puncture was 10.44±5.06 min and about 67% of the FST patients were recanalized at the first attempt. Three-months modified Rankin Scale (mRS) score of ≤2 was observed in 52% of the patients. CONCLUSIONS: Forced suction thrombectomy using the SOFIA Plus yielded a high recanalization rate within a shorter time. In particular, the recanalization rate was higher than that reported in previous studies using other types of suction devices.

Optimal Duration of Dual Antiplatelet Therapy after Stent- Assisted Coil Embolization of Unruptured Intracranial Aneurysms : A Prospective Randomized Multicenter Trial.

OBJECTIVE: Stent-assisted coil embolization (SAC) has been increasingly used to treat various types of intracranial aneurysms. Delayed thromboembolic complications are major concerns regarding this procedure, so dual antiplatelet therapy with aspirin and clopidogrel is needed. However, clinicians vary the duration of dual antiplatelet therapy after SAC, and no randomized study has been performed. This study aims to compare the safety and efficacy of long-term (12 months) dual antiplatelet therapy and shortterm dual antiplatelet therapy (6 months) after SAC for patients with unruptured intracranial aneurysms (UIAs). METHODS: This is a prospective, randomized and multicenter trial to investigate the optimal duration of dual antiplatelet therapy after SAC in patients with UIAs. Subjects will receive dual antiplatelet therapy for 6 months (short-term group) or 12 months (longterm group) after SAC. The primary endpoint is the assessment of thromboembolic complications between 1 and 18 months after SAC. We will enroll 528 subjects (264 subjects in each group) and perform 1 : 1 randomization. This study will involve 14 topperforming, high-volume Korean institutions specializing in coil embolization. RESULTS: The trial will begin enrollment in 2022, and clinical data will be available after enrollment and follow-up. CONCLUSION: This article describes that the aim of this prospective randomized multicenter trial is to compare the effect of short-term (6 months) and long-term (12 months) dual antiplatelet therapy on UIAs in patients undergoing SAC, and to find the optimal duration.

Novel Noncrossing Y-Stent Technique Using Tapered Proximal End of a Solitaire AB Stent for Coil Embolization of Wide-Neck Bifurcation Aneurysms.

The crossing Y-stent method is one of the indispensable techniques to achieve sufficient neck coverage during coil embolization of bifurcation aneurysms with a wide neck and/or branch incorporation. However, the inevitable hourglass-like expansion of the second stent at the crossing point can result in insufficient vessel wall apposition, reduced aneurysm neck coverage, delayed endothelialization, and subsequent higher risks of acute or delayed thrombosis. It also interferes with engagement of the microcatheter into the aneurysm after stent installation. We expected to be able to reduce these disadvantages by installing a noncrossing type Y-stent using the Solitaire AB stent, which is fully retrievable with a tapered proximal end. Here we report the techniques and two successful cases.

Comparative Cadaveric Analysis for Surgical Corridor and Maneuverability: Far-Lateral Approach and Its Transcondylar Extension.

OBJECTIVE: The necessity of partial occipital condyle (OC) resection for lesions in the ventral craniocervical junction is debatable. This study's purpose was to compare the surgical exposure of the classic far-lateral approach (FLA) and transcondylar FLA. METHODS: The classic FLA and transcondylar FLA were performed in 12 human cadaveric heads (24 sides). The surgical corridor of 3 levels (a: vagus nerve, b: from the midpoint of proximal ends of the vagus and hypoglossal nerves to the midpoint of the distal ends of each nerve, c: hypoglossal nerve) and the maneuverability (the area between neurovascular structures that limits instrumental maneuvers) were measured after each approach. RESULTS: The surgical corridors were significantly greater in transcondylar FLA than in classic FLA (a: 14.4 ± 3.4 mm vs. 17.1 ± 4.4 mm, P < 0.001; b: 8.6 ± 2.9 mm vs. 11.2 ± 4.1 mm, P < 0.001; c: 5.5 ± 2.2 mm vs. 7.7 ± 2.8 mm, P < 0.001). Transcondylar FLA also provided greater maneuverability than classic FLA (73.2 ± 23.9 mm2 vs. 94.9 ± 32.2 mm2, P < 0.001). The increased length of the surgical corridor was greatest in a (a: 2.7 ± 2.3 mm, b: 2.6 ± 2.0 mm, c: 2.2 ± 1.4 mm). However, the rate of increase was greatest in c (a: 18.9 ± 16.4%, b: 30.4 ± 26.2%, c: 44.8 ± 27.2%). The area of increased maneuverability was 21.7 ± 20.3 mm2 (31.1 ± 27.8%) after partial OC resection. CONCLUSIONS: Transcondylar FLA can significantly increase surgical exposure compared with the classic FLA, although also increasing surgical complications. Therefore, the surgical approach should be individualized according to each lesion and patient. The results of our study may assist in surgical decision-making regarding the need for OC resection.

The Assessment of Geometric Reliability of Conventional Trajectory of Ventriculostomy in a Three Dimensional Virtual Model and Proposal of a New Trajectory.

Ventriculostomy is a common neurosurgery procedure performed for many purposes. Kocher's point is most often used as the ventriculostomy entry point. But the accuracy of a cannula's trajectory into the ventricles from entry at Kocher's point is controversial. In this paper we attempt to evaluate the accuracy of the conventional sagittal trajectory, which uses Kocher's point, and evaluate a new trajectory by creating virtual ventriculostomy simulations from computed tomography images of the brain. About 66 patients without brain and skull pathology in radiography were included. Three dimensional images were constructed using thin sliced brain computed tomography images, and a virtual ventriculostomy was performed toward the previous used surface landmark. And the path of ideal ventricular catheter was simulated. The anterior surface landmarks included the ipsilateral medial canthus, the contralateral medial canthus, and the midpoint between bilateral medial canthi. The lateral surface landmark was the external auditory canal. The sagittal trajectory of the three surface landmarks located in the frontal horn of ipsilateral ventricle was 0% for the ipsilateral medial canthus, 87.88% for the midpoint between bilateral medial canthi and 26.52% for the contralateral medial canthus. The anterior surface target of ideal sagittal trajectory, which connects the Kocher's point with the central axis of ipsilateral ventricle, is contralaterally 6.7 mm away from midline. It was found that the conventional sagittal trajectory is inaccurate. The anterior target of surface landmark for the ideal sagittal trajectory is medial one third of the distance between the midline and the contralateral medial canthus.