A case of bilateral vertebral artery dissection treated by bilateral surgical occlusion and low-flow bypass.

Background: Bilateral vertebral artery dissection aneurysm (VADA) is a rare condition that leads to severe stroke. However, the surgical strategy for its treatment is controversial because the pathology is very complicated and varies in each case. Here, we report a case of bilateral VADA that was successfully treated with staged bilateral VADA occlusion and low-flow bypass. Case Description: A Japanese man in his 40s presented with bilateral VADA with subarachnoid hemorrhage. He had only mild headaches without any other neurological deficits. Subsequently, the ruptured left VADA was surgically trapped. However, on postoperative day 11, the contralateral VADA enlarged. The right VADA was then proximally clipped via a lateral suboccipital approach. Furthermore, a superficial temporal artery-superior cerebellar artery bypass was performed through a subtemporal approach in advance to preserve cerebral flow in the posterior circulation. The bilateral VADA was obliterated, and the patient had an uneventful postoperative course during the 1-year and 6-month follow-up period. Conclusion: Bilateral VADA can be successfully treated with staged bilateral VADA obstruction and low-flow bypass. In this case, as the posterior communicating arteries were the fetal type and the precommunicating segments of the posterior cerebral arteries (P1) were hypoplastic, a low-flow bypass was used to supply the basilar and cerebellar arteries, except the posterior cerebral and posterior inferior cerebellar arteries. Furthermore, low-flow bypass is a less invasive option than high-flow bypass.

Comparison of efficacy between clazosentan and fasudil hydrochloride-based management of vasospasm after subarachnoid hemorrhage focusing on older and WFNS grade V patients: a single-center experience in Japan.

Subarachnoid hemorrhage often leads to poor outcomes owing to vasospasm, even after successful aneurysm treatment. Clazosentan, an endothelin receptor inhibitor, has been proven to be an effective treatment for vasospasms in a Japanese randomized controlled trial. However, its efficacy in older patients (≥ 75 years old) and those with World Federation of Neurosurgical Societies (WFNS) grade V has not been demonstrated. We retrospectively evaluated the efficacy of clazosentan in older patients and those with WFNS grade V, using real-world data. Patients with subarachnoid hemorrhage treated before and after the introduction of clazosentan were retrospectively evaluated. The patients were categorized into two groups (clazosentan era versus pre-clazosentan era), in which vasospasm management and outcomes were compared. Vasospasms were managed with fasudil hydrochloride-based (pre-clazosentan era) or clazosentan-based treatment (clazosentan era). Seventy-eight patients were included in this study: the clazosentan era (n = 32) and pre-clazosentan era (n = 46). Overall, clazosentan significantly reduced clinical vasospasms (clazosentan era: 31.3% versus pre-clazosentan era: 60.9%, p = 0.01), delayed cerebral ischemia (DCI) (9.4% versus 39.1%, p = 0.004), and vasospasm-related morbidity and mortality (M/M) (3.1% versus 19.6%, p = 0.03). In subgroup analysis of older patients or those with WFNS grade V, no significant difference was observed in clinical outcomes, although both DCI and vasospasm-related M/M were lower in the clazosentan era. Clazosentan was more effective than fasudil-based management in preventing DCI and reducing vasospasm-related M/M. Clazosentan could be used safely in older patients and those with WFNS grade V, although clinical outcomes in these patients were comparable to those of conventional treatment.

C5a-C5AR1 axis as a potential trigger of the rupture of intracranial aneurysms.

Recent studies have indicated the involvement of neutrophil-mediated inflammatory responses in the process leading to intracranial aneurysm (IA) rupture. Receptors mediating neutrophil recruitment could thus be therapeutic targets of unruptured IAs. In this study, complement C5a receptor 1 (C5AR1) was picked up as a candidate that may cause neutrophil-dependent inflammation in IA lesions from comprehensive gene expression profile data acquired from rat and human samples. The induction of C5AR1 in IA lesions was confirmed by immunohistochemistry; the up-regulations of C5AR1/C5ar1 stemmed from infiltrated neutrophils, which physiologically express C5AR1/C5ar1, and adventitial fibroblasts that induce C5AR1/C5ar1 in human/rat IA lesions. In in vitro experiments using NIH/3T3, a mouse fibroblast-like cell line, induction of C5ar1 was demonstrated by starvation or pharmacological inhibition of mTOR signaling by Torin1. Immunohistochemistry and an experiment in a cell-free system using recombinant C5 protein and recombinant Plasmin indicated that the ligand of C5AR1, C5a, could be produced through the enzymatic digestion by Plasmin in IA lesions. In conclusion, we have identified a potential contribution of the C5a-C5AR1 axis to neutrophil infiltration as well as inflammatory responses in inflammatory cells and fibroblasts of IA lesions. This cascade may become a therapeutic target to prevent the rupture of IAs.

Difference in Clinical Phenotype, Mutation Position, and Structural Change of RNF213 Rare Variants Between Pediatric and Adult Japanese Patients with Moyamoya Disease.

It is unclear how rare RNF213 variants, other than the p.R4810K founder variant, affect the clinical phenotype or the function of RNF213 in moyamoya disease (MMD). This study included 151 Japanese patients with MMD. After performing targeted resequencing for all coding exons in RNF213, we investigated the clinical phenotype and statistically analyzed the genotype-phenotype correlation. We mapped RNF213 variants on a three-dimensional (3D) model of human RNF213 and analyzed the structural changes due to variants. The RNF213 p.R4810K homozygous variant, p.R4810K heterozygous variant, and wild type were detected in 10 (6.6%), 111 (73.5%), and 30 (19.9%) MMD patients, respectively. In addition, 15 rare variants were detected in 16 (10.6%) patients. In addition to the influence of the p.R4810K homozygous variant, the frequency of cerebral infarction at disease onset was higher in pediatric patients with other rare variants (3/6, 50.0%, P = 0.006) than in those with only the p.R4810K heterozygous variant or with no variants (2/51, 3.9%). Furthermore, on 3D modelling of RNF213, the majority of rare variants found in pediatric patients were located in the E3 module and associated with salt bridge loss, contrary to the results for adult patients. The clinical phenotype of rare RNF213 variants, mapped mutation position, and their predicted structural change differed between pediatric and adult patients with MMD. Rare RNF213 variants, in addition to the founder p.R4810K homozygous variant, can influence MMD clinical phenotypes or structural change which may contribute to the destabilization of RNF213.

Application of protective superficial temporal artery to middle cerebral artery bypass through the lateral supraorbital approach: Technical note.

OBJECTIVE: The lateral supraorbital (LSO) approach is a minimally invasive craniotomy widely used in the surgical treatment of intracranial aneurysms (IAs). A protective bypass is considered a safety measure in high-risk and complex clipping procedures to maintain distal cerebral flow. However, the protective bypass has so far only been applied through a pterional or larger craniotomy. We aimed to describe the characteristics of the superficial temporal artery to middle cerebral artery (STA-MCA) bypass through the LSO craniotomy to treat complex IAs. METHODS: We retrospectively identified six patients with complex IAs who underwent clipping and a protective STA-MCA bypass through the LSO approach between January 2016 and December 2020. The STA donor artery was harvested through the same curvilinear skin incision with a small extension, and it was anastomosed to the opercular segment of the MCA. Subsequently, aneurysm clipping followed standardized steps. RESULTS: Anastomosis was successful in all patients. Despite requiring temporary occlusion of the parent artery, all aneurysms were successfully clipped without any neurological deterioration. CONCLUSIONS: A protective STA-MCA bypass is feasible through the LSO approach with certain technical modifications. This technique helps protect distal cerebral flow for safe clip placement in the treatment of complex IAs with the associated benefits of a less invasive craniotomy.

Hypoxic microenvironment as a crucial factor triggering events leading to rupture of intracranial aneurysm.

Subarachnoid hemorrhage being the rupture of intracranial aneurysm (IA) as a major cause has quite poor prognosis, despite the modern technical advances. Thereby, the mechanisms underlying the rupture of lesions should be clarified. Recently, we and others have clarified the formation of vasa vasorum in IA lesions presumably for inflammatory cells to infiltrate in lesions as the potential histopathological alternation leading to rupture. In the present study, we clarified the origin of vasa vasorum as arteries located at the brain surface using 3D-immunohistochemistry with tissue transparency. Using Hypoxyprobe, we then found the presence of hypoxic microenvironment mainly at the adventitia of intracranial arteries where IA is formed. In addition, the production of vascular endothelial growth factor (VEGF) from cultured macrophages in such a hypoxic condition was identified. Furthermore, we found the accumulation of VEGF both in rupture-prone IA lesions induced in a rat model and human unruptured IA lesions. Finally, the VEGF-dependent induction of neovessels from arteries on brain surface was confirmed. The findings from the present study have revealed the potential role of hypoxic microenvironment and hypoxia-induced VEGF production as a machinery triggering rupture of IAs via providing root for inflammatory cells in lesions to exacerbate inflammation.

Predictive factors for improvement of symptomatic cerebral vasospasm following subarachnoid hemorrhage by selective intra-arterial administration of fasudil hydrochloride.

BACKGROUND: Symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) is a significant cause of delayed cerebral ischemia that leads to poor outcomes. Selective intra-arterial administration of fasudil hydrochloride (IAF) has been adopted for its vasodilatory effect on spasm arteries to prevent delayed cerebral ischemia. However, its effect on clinical outcomes and predictive factors for good recovery are not fully understood. This study aimed to investigate the outcomes of selective IAF and identify predictive factors for good outcomes in patients with cerebral vasospasm after SAH. METHODS: A retrospective study of 36 patients with cerebral vasospasm following SAH who underwent selective IAF at our institution between January 2014 and May 2022 was conducted. We evaluated the improvements in neurological findings before and after selective IAF. Statistical analyses were performed to determine factors associated with good outcomes. RESULTS: Selective IAF improved the neurological findings in 26 patients (72.2%). Pre-therapeutic absence of cerebral infarction in more than 1/3 of the spasm artery perfusion area was significantly associated with an improvement in neurological findings (p < 0.0001). Furthermore, there was a tendency for a good outcome when the age was younger (p = 0.093), and the spasm was limited to peripheral vessels (p = 0.065). CONCLUSION: Our study indicates that selective IAF has a promising effect in improving symptomatic vasospasm, except when a large cerebral infarction exists in the spasm artery perfusion area. Early consideration of selective IAF could be recommended once patients experience symptomatic cerebral vasospasm after SAH.

Efficacy of 3D evaluation of unruptured paraclinoid aneurysms within Leksell GammaPlan® for determination of their intradural localization.

BACKGROUND: Determination of the intradural unruptured paraclinoid aneurysm localization is difficult, but critical for selection of the optimal treatment strategy. OBJECTIVE: To assess efficacy of the three-dimensional (3D) evaluation of unruptured paraclinoid aneurysms within Leksell GammaPlan® (LGP; Elekta AB; Stockholm, Sweden) for determination of their intradural localization. METHODS: Overall, 125 incidentally diagnosed unruptured paraclinoid aneurysms in 118 patients (mean age, 55 years) underwent 3D evaluation of their localization within LGP using post-contrast thin-slice constructive interference in steady state (CISS) images, which in 41 cases were additionally co-registered and fused with the axial computed tomography angiography (CTA) source images. RESULTS: According to the evaluation within LGP, paraclinoid aneurysms were considered intradural, transitional, and extradural in 75, 25, and 25 cases respectively. Overall, 51 of 75 aneurysms deemed to be intradural, underwent microsurgical management, and intraoperative visual inspection confirmed their intradural localization in 45 cases, whereas it was transitional in 3, and extradural in 3. If during preoperative 3D evaluation within LGP only post-contrast CISS images were used, prediction of the pure intradural localization of aneurysm was correct in 88 % of cases (95 % CI: 79-97 %), and of the pure or partial (i.e., transitional) intradural localization in 94 % of cases (95 % CI: 88-100 %), whereas it was 100 % if co-registration and fusion of the contrast-enhanced CISS and CTA source images was done. CONCLUSION: Intradural localization of the unruptured paraclinoid aneurysms may be effectively predicted based on their 3D evaluation within LGP using post-contrast thin-slice CISS and CTA source images, which may help with clinical decision-making.

Transient neurological events in childhood moyamoya disease.

OBJECTIVE: Patients sometimes experience transient neurological events (TNEs) during the early postoperative period after revascularization surgery for childhood moyamoya disease. The clinical background and pathophysiology of TNEs remain unclear. This study aimed to evaluate the incidence rate of TNEs and discuss the factors associated with pediatric moyamoya disease. METHODS: The authors retrospectively reviewed 110 cerebral hemispheres of 61 pediatric patients younger than 15 years who were treated from 2011 to 2020. All children underwent either simple double-direct or combined revascularization surgery. Of these 61 patients, 52 underwent bilateral surgery and 9 underwent unilateral surgery. The authors calculated the incidence of TNEs in accordance with a previously reported TNE definition. Cerebral blood flow (CBF) was evaluated in all eligible cases with xenon CT immediately after revascularization surgery. RESULTS: The incidence rate of TNEs in patients with childhood moyamoya disease was 26.4%. TNEs occurred after an average (range) of 6.26 (2-12) days postoperatively without triggers, and all identified TNEs spontaneously resolved within 2 weeks. The most common symptoms were dysarthria, facial palsy, and numbness around the mouth, followed by sensory disturbance of the upper extremities. The presence of focal hyperperfusion on xenon CT performed immediately after revascularization surgery was strongly correlated with the incidence of TNEs (p = 0.0001). Focal hyperperfusion was observed in 43 of 110 operative sides (39.1%). Notably, only 25.6% of patients with focal hyperperfusion showed numerical global hyperperfusion. In addition, a decrease in CBF compared with the thalamic region in the contralateral side was observed in TNE-affected cases (p = 0.0443). CONCLUSIONS: TNEs occurred more frequently in childhood moyamoya disease patients than expected. The clinical background, including symptoms, timing, and duration, was almost identical to TNEs in adults. Focal hyperperfusion, rather than numerical global hyperperfusion, was strongly correlated with the incidence of TNEs. Furthermore, the authors advocate the notion that a clinical course where symptoms occur without triggers may be a unique characteristic of TNEs, especially in childhood moyamoya disease.

Endothelial cell malfunction in unruptured intracranial aneurysm lesions revealed using a 3D-casted mold.

Intracranial aneurysms (IA) are major causes of devastating subarachnoid hemorrhages. They are characterized by a chronic inflammatory process in the intracranial arterial walls triggered and modified by hemodynamic force loading. Because IA lesion morphology is complex, the blood flow conditions loaded on endothelial cells in each portion of the lesion in situ vary greatly. We created a 3D-casted mold of the human unruptured IA lesion and cultured endothelial cells on this model; it was then perfused with culture media to model physiological flow conditions. Gene expression profiles of endothelial cells in each part of the IA lesion were then analyzed. Comprehensive gene expression profile analysis revealed similar gene expression patterns in endothelial cells from each part of the IA lesion but gene ontology analysis revealed endothelial cell malfunction within the IA lesion. Histopathological examination, electron microscopy, and immunohistochemical analysis indicated that endothelial cells within IA lesions are damaged and dysfunctional. Thus, our findings reveal endothelial cell malfunction in IA lesions and provided new insights into IA pathogenesis.

Coagulation Technique for Remodeling Anastomosis Spaces in Bypass Surgery.

Cerebrovascular bypass techniques are the current cornerstone methods to achieve cerebral revascularization for moyamoya disease or syndrome and select cases of vascular pathologies, such as intracranial atherosclerotic occlusive disease and complex aneurysms. Factors influencing bypass efficiency include graft patency, short temporary occlusion time, and precise anastomosis. On the basis of our senior author's vast experience with 1300 bypasses, we recommend performing the anastomosis with the minimal number of stitches as achievable to avoid stenosis of the artery's internal lumen that may occur with unnecessary, additional stitches, preserving patency. After completing the anastomosis, when a leak occurs between the sutures, cottonoid tamponade, hemostatic materials, or adding 1 or 2 sutures to the space is often enough to close the gap. However, additional suture placement can be difficult, which might cause stenosis of the anastomosis and reduce blood flow. In this video, we introduce a bipolar coagulation technique for remodeling the anastomosis orifices, as an alternative manner, when minor leakages occur between the knots (Video 1). We demonstrate this technique in an adult moyamoya disease patient who underwent a superficial temporal artery-to-middle cerebral artery bypass, in this case coagulation of the donor artery wall at the anastomosis made possible to adapt the edges of the donor artery precisely to the recipient artery wall by shrinking its redundancy between the stitches. The most important task is to coagulate the donor side orifice precisely with low-power bipolar coagulation and never coagulate the recipient artery. This coagulation technique is a simple alternative to stop further leakage, and it prevents placing an additional suture and reduces temporary occlusion time.

Horizontal stent deployment via extracranial-intracranial bypass in coil embolization of basilar apex aneurysms: technical report.

BACKGROUND: The endovascular treatment of large, wide-necked basilar apex aneurysms (BAAs) remains challenging. Although horizontal stent deployment across both P1 segments of the posterior cerebral arteries (PCAs) would be an optimal strategy in coil embolization of wide-necked BAAs, this is only feasible in cases with anatomically favorable access. In rare circumstances, large-diameter conduits of extracranial-intracranial (EC-IC) bypass can also provide a good access route for endovascular treatment of complex intracranial aneurysms. METHODS: We describe the technique of accessing the PCA via EC-IC bypass grafts and deploying a stent horizontally across the neck of BAA and its coil embolization. We provide a detailed technical review and describe some pitfalls of the procedure. RESULTS: Two patients underwent EC-IC bypass surgery prior to the treatment of a large, wide-necked BAA. The radial artery and saphenous vein were used as grafts, respectively. To facilitate coil embolization for a large BAA, a PCA-to-PCA horizontal stent was deployed via the bypass graft. Trans-cell and jailing techniques were used, respectively. Both aneurysms were completely occluded, and the patients were discharged without any neurological deficit. CONCLUSION: Horizontal stent deployment via EC-IC bypass grafts can be performed safely, providing proper closure of the aneurysmal neck and apposition to both PCAs, facilitating complete coil embolization.

Five-Day Bed Rest Reduces Postoperative Intracerebral Hemorrhage After Direct Bypass for Moyamoya Disease.

OBJECTIVE: Postoperative intracerebral hemorrhage (ICH) after direct bypass surgery for Moyamoya disease could contribute to neurologic deterioration. The aim of this study was to evaluate the effectiveness of 5-day bed rest in reducing the occurrence of postoperative ICH. METHODS: This study included 122 consecutive hemispheres in 87 Japanese adult MMD patients, composed of 80 control hemispheres from historical data and 42 hemispheres after 5-day bed rest. They all underwent direct bypass surgery. The incidence of postoperative ICH and neurologic deterioration assessed via the modified Rankin Scale were investigated and statistically analyzed. RESULTS: Postoperative ICH was observed in 9 out of the 80 (11.3%) control patients, but not in the 42 patients with 5-day bed rest. The incidence of postoperative ICH and neurologic deterioration via the modified Rankin Scale were significantly different between the 2 groups (P = 0.0268 and 0.0078, respectively). Univariate logistic analysis revealed that 5-day bed rest significantly reduced the incidence of postoperative ICH (P = 0.0048). CONCLUSIONS: Five-day bed rest after direct bypass surgery dramatically can reduce the incidence of postoperative ICH and neurologic deterioration after direct bypass surgery.

Maximum Nidus Depth as a Risk Factor of Surgical Morbidity in Eloquent Brain Arteriovenous Malformations.

BACKGROUND: Eloquent location of a brain arteriovenous malformation (BAVM) is known to increase the surgical risk. Surgical removal of such BAVMs is challenging. Useful indicators for the safe removal of eloquent BAVMs are needed. The aim of this study was to determine the surgical risk factors for these challenging entities. METHODS: The authors retrospectively reviewed 29 motor and/or sensory BAVM patients who underwent surgeries. The risk factors for surgical morbidity were analyzed. As a new risk factor, maximum nidus depth, was evaluated. RESULTS: Complete obliteration was achieved in 28 patients (96.6%). Postoperative transient and permanent neurological deteriorations were seen in nine patients (31.0%) and five patients (17.2%), respectively. In univariate analysis, maximum nidus depth (p = 0.0204) and asymptomatic onset (p = 0.0229) were significantly correlated with the total morbidity. In multivariate analysis, only maximum nidus depth was significantly correlated with total morbidity (p = 0.0357; odds ratio, 2.78598; 95% confidence interval, 0.8866-8.7535). The cut-off value for the maximum nidus depth was 36 mm for total morbidity (area under the curve [AUC], 0.7428) and 41 mm for permanent morbidity (AUC, 0.8833). The cutoff value of the maximum nidus size was 30 mm for total morbidity (AUC, 0.5785) and 30 mm for permanent morbidity (AUC, 0.7625). AUC was higher for the maximum nidus depth than it was for the maximum nidus size. CONCLUSIONS: Maximum nidus depth was significantly associated with surgical morbidity of eloquent BAVMs. The maximum nidus depth is a novel and a simpler indicator of the risk of surgical morbidity.

Induction of CCN1 in Growing Saccular Aneurysms: A Potential Marker Predicting Unstable Lesions.

Growing evidence has suggested that inflammatory responses promote the progression of saccular intracranial aneurysms (IAs). However, a biomarker predicting the progression has yet to be established. This study aimed to identify novel molecules upregulated during the progression using a previously established rat aneurysm model. In this model, aneurysms are induced at the surgically created common carotid artery (CCA) bifurcation. Based on sequential morphological data, the observation periods after the surgical manipulations were defined as the growing phase (on the 10th day) or the stable phase (on the 30th day). Total cell lysates from the CCA with or without an aneurysm lesion were prepared to perform protein array analysis. The protein array analysis revealed that the matricellular protein cellular communication network factor 1 (CCN1) is induced in lesions during the growing phase. Immunohistochemistry corroborated the significant upregulation of CCN1 in the growing phase compared with the stable phase. Simultaneously with the induction of CCN1, significant increases in the number of CD68-positive macrophages, myeloperoxidase-positive cells, and proliferating smooth muscle cells in lesions were observed. Immunohistochemistry of human IA specimens reproduced the induction of CCN1 in some lesions. These findings imply a potential role of CCN1 as a marker predicting the progression of saccular aneurysms.

A case of idiopathic extracranial carotid artery pseudoaneurysm with a rare clinical course and pathological features.

Extracranial carotid artery aneurysms (ECAAs) are rare, with the etiology mainly classified as degeneration or dissection. Pseudoaneurysms in the region are even rarer and are seen following trauma, iatrogenic injury, or infection. We report a case of extracranial carotid artery pseudoaneurysm (pseudo-ECAA) with a rare clinical course and pathological features. A 58-year-old man presented with swelling and purpura on the left side of his neck after sneezing. Radiological examinations suggested a ruptured left common carotid artery aneurysm. The operative findings were consistent with a pseudoaneurysm. Pathological examination revealed disarrangement and degeneration of smooth muscle fibers in the media, in addition to scattered foci of mucoid accumulation and irregular-shaped cavitation in the medial extracellular matrix, raising the possibility of an intrinsic dysfunction of the vascular wall in the pathological process of pseudoaneurysm formation.

Occipital artery to middle cerebral artery bypass in pediatric moyamoya disease: rescue therapy after failed revascularization.

OBJECTIVE: Patients with pediatric moyamoya disease (PMMD) showing recurrent symptoms or decreased cerebral blood flow after initial revascularization therapy may require additional revascularization to improve their clinical condition. The authors evaluated the clinical and hemodynamic benefits of an occipital artery (OA)-middle cerebral artery (MCA) bypass for patients with PMMD who have undergone an initial revascularization procedure. METHODS: The authors retrospectively identified 9 patients with PMMD who had undergone OA-MCA bypass between March 2013 and December 2017, and who had received a previous superficial temporal artery-MCA bypass. The following clinical data were collected: initial revascularization procedure, symptoms (presence or recurrence), pre- and postoperative cerebral blood flow and cerebrovascular reactivity (CVR) changes, posterior cerebral artery (PCA) stenosis, PCA-related and nonrelated symptoms, and latest follow-up. RESULTS: Preoperatively, all patients (n = 9) suffered non-PCA-related recurrent symptoms, and 4 had PCA-related symptoms. At 1-year follow-up, all patients with PCA-related symptoms showed complete recovery. Additionally, 8 (89%) patients with non-PCA symptoms experienced improvement. Only 1 (11%) patient showed no improvement after the surgical procedure. The mean pre- and postoperative CVR values of the MCA territory were 14.8% and 31.3%, respectively, whereas the respective mean CVR values of the PCA territory were 22.8% and 40.0%. CONCLUSIONS: The OA-MCA bypass is an effective rescue therapy to improve the clinical condition and hemodynamic changes caused by PMMD in patients who experience recurrent symptoms after initial revascularization.

Pre-Therapeutic Factors Predicting for the Necessity of Rescue Treatments in Mechanical Thrombectomy.

Objective: Mechanical thrombectomy for acute large vessel occlusion (LVO) is currently widely performed. However, rescue treatment (RT), such as percutaneous transluminal angioplasty (PTA) and stenting, is occasionally required, particularly in the case of atherothrombotic brain infarction (ATBI) or dissection. As RT requires higher levels of therapeutic skills and additional devices, early prediction of its performance and preparation are important. We retrospectively investigated the pre-therapeutic factors for predicting the necessity of RT. Methods: We reviewed 149 consecutive patients who underwent mechanical thrombectomy for acute LVO between April 2014 and December 2019. Eight patients were excluded because of missing clinical data. RT was performed when severe stenosis was observed in occluded vessels or proximal to them during mechanical thrombectomy. We investigated pre-therapeutic neurological, laboratory, and radiological findings in the 141 remaining patients, and compared them between RT and non-RT groups. Results: RT was performed on 23 of the 141 patients. We found four pre-therapeutic factors with significantly different rates between RT/non-RT as follows: (1) Atrial fibrillation 8.7%/71.1% (p <0.001), (2) diabetes mellitus 39.1%/19.5% (p = 0.04), (3) susceptibility vessel sign (SVS) by T2-weighted imaging 17.4%/66.1% (p <0.001), and (4) tapered occlusion by magnetic resonance angiography (MRA) 47.8%/11.9% (p <0.001). The plasma level of brain natriuretic peptide (BNP) was also significantly different between the two groups. When the BNP level was less than 70 pg/mL, the sensitivity for being in the RT group was 86.9% and the specificity was 83.5%. Conclusion: Pre-therapeutic findings, such as diabetes mellitus, tapered occlusion, absence of atrial fibrillation, negative SVS, and BNP level less than 70 pg/mL, are predictors of RT in mechanical thrombectomy.

[Advantages and Pitfalls of the Lateral Supraorbital Approach as Less Invasive Surgery for Unruptured Anterior Circulation Aneurysms].

The lateral supraorbital approach(LSOA)is widely accepted as a less invasive surgical technique compared with the conventional pterional approach(PA). However, only a few studies have reported less invasiveness associated with LSOA. To evaluate this issue, we retrospectively investigated the surgical outcomes in 133 patients who underwent LSOA and 28 patients who underwent PA for unruptured anterior circulation aneurysms. We analyzed operation time, postoperative symptoms and complications, and the length of postoperative hospitalization(in days)for each method. All aneurysms were successfully clipped regardless of the approach. The operation time was significantly shorter, the postoperative headache rate was lower, resumption of oral intake was more rapid, and length of hospitalization was shorter in the LSOA group. Statistical significance was not observed in the postoperative complication rates. Compared with conventional PA, LSOA was associated with less invasiveness and better patient satisfaction. LSOA is a safe and effective alternative to conventional PA, following optimal patient selection.

Do Direct Bypasses Really Resolve Capillary Vessels in Moyamoya Disease? Delayed Hemorrhage Potentially Relevant to Direct Bypasses: A Pathological Investigation.

OBJECTIVE: Moyamoya disease is a chronic but progressive obliterative cerebrovascular disease of bilateral internal carotid arteries (ICAs) causing hemorrhagic or ischemic cerebral strokes. Surgical revascularization has the potential for resolving the capillary vessels, but the effect on the occlusive ICA and the moyamoya vessels after a direct bypass remains unclear. PATIENT: A 2-year-old girl with a history of repeated transient ischemic attacks and direct bypasses but demonstrating improvement and associated anomaly is reported. A year and a half later, after a bilateral revascularization, an intracerebral capsulized hematoma growth was identified, and it was removed surgically. Neovascularization including many microvessels similar to capillary telangiectasia were identified by pathological investigation despite the reduction of moyamoya vessels on the repeated angiograms after the revascularization surgeries. In the present case, proliferation of capillary vessels was clearly confirmed by direct bypasses. CONCLUSION: There is no doubt that direct bypasses prevent further ischemic stroke by improving cerebral blood flow. However, they may result in failure in reducing the load of moyamoya vessels, albeit decreasing the potential risk of hemorrhagic strokes.