[Microvascular Decompression for Trigeminal Neuralgia Due to Venous Compression].

In microvascular decompression surgery for trigeminal neuralgia, the veins are essential as an anatomical frame for the microsurgical approach and as an offending vessel to compress the trigeminal nerve. Thorough arachnoid dissection of the superior petrosal vein and its tributaries provides surgical corridors to the trigeminal nerve root and enables the mobilization of the bridging, brainstem, and deep cerebellar veins. It is necessary to protect the trigeminal nerve by coagulating and cutting the offending vein. We reviewed the clinical features of trigeminal neuralgia caused by venous decompression and its outcomes after microvascular decompression. Among patients with trigeminal neuralgia, 4%-14% have sole venous compression. Atypical or type 2 trigeminal neuralgia may occur in 60%-80% of cases of sole venous compression. Three-dimensional MR cisternography and CT venography can help in detecting the offending vein. The transverse pontine vein is the common offending vein. The surgical cure and recurrence rates of trigeminal neuralgia with venous compression are 64%-75% and 23%, respectively. Sole venous compression is a unique form of trigeminal neuralgia. Its clinical characteristics differ from those of trigeminal neuralgia caused by arterial compression. Surgical procedures to resolve venous compression include nuances in safely handling venous structures.

Exoscopic microvascular decompression for hemifacial spasm and trigeminal neuralgia.

The 4K 3D exoscope system is becoming increasingly used in neurosurgery. Its 3D ultra-high-definition image is valuable in identifying and dissecting the delicate neural and vascular structures during microvascular decompression. In this video, the authors describe several nuances and details to perform the exoscopic microvascular decompression, including the exoscope layout and the modified supine position. Several illustrative case presentations highlight the benefits of exoscopic surgery. The authors' exoscopic microvascular decompression series of 159 patients showed noninferior surgical outcomes compared to the operative microscope with no significant increase in surgical risk. In conclusion, an exoscope can be a practical alternative to performing microvascular decompression. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23122.

Risk of Bone Wax Migration During Retrosigmoid Craniotomy for Microvascular Decompression: Case-Control Study.

BACKGROUND AND OBJECTIVES: Bone wax is a flexible hemostatic agent commonly used for surgery in the posterior cranial fossa to control bleeding from the mastoid emissary vein. A large amount of bone wax can migrate into the sigmoid sinus through the mastoid emissary canal (MEC). We aimed to identify clinical factors related to intraoperative bone wax migration through the MEC during microvascular decompression (MVD) surgery, which may result in sigmoid sinus thrombosis. METHODS: We retrospectively collected the clinical data of patients with trigeminal neuralgia, hemifacial spasm, or trigeminal neuralgia accompanied by painful tic convulsif who underwent MVD. Basic information and the residual width and length (from the bone surface to the sigmoid sinus) of the MEC on computed tomography images were collected. We compared the collected clinical data between 2 groups of cases with and without intraoperative bone wax migration in the sigmoid sinus. RESULTS: Fifty-four cases with intraoperative bone wax migration and 187 patients without migration were enrolled. The t -test revealed significant differences in the width and length of the MEC ( P = .013 and P = .003, respectively). These variables were identified as significant factors in predicting intraoperative bone wax migration using multivariate logistic regression analysis. CONCLUSION: The large size of the MEC may be related to intraoperative bone wax migration into the sigmoid sinus in MVD. Neurosurgeons should be aware of these risks. Bone wax should be applied appropriately and hemostasis should be considered to control bleeding from the mastoid emissary vein in patients with a large MEC.

Factors for failure of ultrasound-guided compression repair for femoral pseudoaneurysms after neuroendovascular therapy.

OBJECTIVE: Pseudoaneurysms are a serious complication of neuroendovascular therapy with femoral artery puncture, for which ultrasound-guided compression repair (UGCR) is often the first choice of radical therapy. We sought to retrospectively investigate the factors for failure of UGCR for pseudoaneurysm at the femoral artery puncture site. METHODS: Among patients undergoing neuroendovascular therapy with femoral artery puncture at our hospital between January 2018 and April 2021, those who received a diagnosis of pseudoaneurysm and underwent UGCR were enrolled. They were classified into two groups according to whether UGCR was successful (UGCR group) or was converted to surgical repair (SR group). Patient and procedural characteristics were compared between the two groups. RESULTS: During the study period, 577 patients underwent neuroendovascular therapy with femoral artery puncture, 10 of whom (1.7%) received a diagnosis of pseudoaneurysm and underwent UGCR. There were seven patients in the UGCR group and three patients in the SR group. The sheath diameter tended to be larger in the SR group than in the UGCR group (p = 0.16). The modified Rankin scale score when a diagnosis of pseudoaneurysm was made was significantly lower in the SR group than in the UGCR group (1 [0-2] vs. 3 [2-5], p = 0.037). CONCLUSIONS: Physical activity may be associated with failure of UGCR. In patients with high physical activity, the use of sedatives and analgesics to keep them at rest during puncture site compression after UGCR may lead to successful UGCR.

Intramedullary feeder aneurysm of a cervical epidural arteriovenous fistula causing myelopathy: a case report and literature review.

While a craniocervical junction (CCJ) epidural arteriovenous fistula (EDAVF) may present with hemorrhagic myelopathy from an associated feeder aneurysm on rare occasions, non-hemorrhagic myelopathy from such an aneurysm remains unreported. A woman in her late sixties presented with cervical myelopathy due to a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF. The intramedullary aneurysm originated from the spinal pial artery supplied by the anterior spinal artery. Direct surgical fistula coagulation and feeder obliteration resulted in the disappearance of the aneurysm and myelopathy improvement. This report illustrates the first case of a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF successfully treated with direct surgery.

Factors related to white thrombi in acute ischemic stroke in cancer patients.

OBJECTIVES: Thrombi in cerebral large vessel occlusion associated with active cancer are often fibrin and platelet-rich white thrombi. However, evaluating the thrombus composition in a short time before thrombectomy is often ineffective. We sought to determine factors related to white thrombi in acute ischemic stroke due to large vessel occlusion in cancer patients. METHODS: Consecutive cancer patients undergoing thrombectomy for acute ischemic stroke due to large vessel occlusion between January 2018 and May 2022 were retrospectively reviewed. The patients were classified into white thrombus and red thrombus groups on the basis of the pathological findings of retrieved thrombi. Patient characteristics and laboratory findings were compared between the two groups. RESULTS: There were 12 patients in the white thrombus group and 11 patients in the red thrombus group. Active cancer was significantly more in the white thrombus group than in the red thrombus group (91.7% vs. 36.3%, p = 0.0094). Internal carotid artery occlusion was significantly less in the white thrombus group than in the red thrombus group (0% vs. 36.4%, p = 0.037). Among laboratory findings, D-dimer levels were an independent factor associated with white thrombi (odds ratio 8.97 [95% confidence interval 1.71-368.99], p < 0.0001). The cutoff value of D-dimer levels for predicting white thrombi was 3.5 µg/mL (83.3% sensitivity and 100% specificity). CONCLUSIONS: In acute ischemic stroke in cancer patients, active cancer, no internal carotid artery occlusion, and higher D-dimer levels (≥3.5 µg/mL) may be associated with occlusion with fibrin and platelet-rich white thrombi.

Intraoperative identification of the lateral spinal artery in a case of craniocervical junction dural arteriovenous fistula surgically obliterated.

BACKGROUND: The formation of a dural arteriovenous fistula (DAVF) at the craniocervical junction is rare. Such a fistula can be fed by the branches of the vertebral and external carotid arteries. The lateral spinal artery can branch from the vertebral artery. The feeders of a DAVF at the craniocervical junction are often diagnosed on preoperative angiography, and there is little reported evidence on the intraoperative diagnosis of the lateral spinal artery. CASE DESCRIPTION: An 84-year-old man presented with motor weakness and sensory disturbance of the lower extremities. Edematous changes in the medulla oblongata and cervical spinal cord were observed on magnetic resonance imaging. Cerebral angiography revealed a DAVF fed by a branch of the vertebral artery, with a shunting point located in the dura of the right condyle; the main drain was the anterior spinal vein. The DAVF drain was surgically obliterated to prevent hemorrhagic events and improve neurological symptoms. Intraoperatively, an artery branching from the feeder of the DAVF was identified and preserved. The patient had a good postoperative course, and the neurological symptoms were ameliorated. Follow-up cerebral angiography revealed proximal branching of the lateral spinal artery from the feeding artery of the DAVF. CONCLUSION: A lateral spinal artery was identified intraoperatively while a DAVF at the craniocervical junction was obliterated. This suggests that preoperative imaging should be carefully reviewed, and endovascular procedures should consider such possibilities to avoid adverse ischemic outcomes.

Predicting the growth of middle cerebral artery bifurcation aneurysms using differences in the bifurcation angle and inflow coefficient.

OBJECTIVE: Growing intracranial aneurysms (IAs) are prone to rupture. Previous cross-sectional studies using postrupture morphology have shown the morphological or hemodynamic features related to IA rupture. Yet, which morphological or hemodynamic differences of the prerupture status can predict the growth and rupture of smaller IAs remains unknown. The purpose of this longitudinal study was to investigate the effects of morphological features and the hemodynamic environment on the growth of IAs at middle cerebral artery (MCA) bifurcations during the follow-up period. METHODS: One hundred two patients with MCA M1-2 bifurcation saccular IAs who underwent follow-up for more than 2 years at the authors' institutions between 2011 and 2019 were retrospectively identified. During the follow-up period, cases involving growth of MCA IAs were assigned to the event group, and those with MCA IAs unchanged in size were assigned to the control group. The morphological parameters examined were aneurysmal neck length, dome height, aspect ratio and volume, M1 and M2 diameters and their ratio, and angle configurations among M1, M2, and the aneurysm. Hemodynamic parameters were flow rate and wall shear stress in M1, M2, and the aneurysm, including the aneurysmal inflow rate coefficient (AIRC), defined as the ratio of the aneurysmal inflow rate to the M1 flow rate. Those parameters were compared statistically between the two groups. Correlations between morphological and hemodynamic parameters were also examined. RESULTS: Eighty-three of 102 patients were included: 25 with growing MCA IAs (event group) and 58 with stable MCA IAs (control group). The median patient age at initial diagnosis was 66.9 (IQR 59.8-72.3) years. The median follow-up period was 48.5 (IQR 36.5-65.6) months. Both patient age and the AIRC were significant independent predictors of the growth of MCA IAs. Moreover, the AIRC was strongly correlated with sharper bifurcation and inflow angles, as well as wider inclination angles between the M1 and M2 arteries. CONCLUSIONS: The AIRC was a significant independent predictor of the growth of MCA IAs. Sharper bifurcation and inflow angles and wider inclination angles between the M1 and M2 arteries were correlated with the AIRC. MCA IAs with such a bifurcation configuration are more prone to grow and rupture.

Cone-beam CT-assisted microcatheter tip placement at the shunted pouch entry zone: A technical note for anterior condylar arteriovenous fistula.

Accurate microcatheter placement for anterior condylar arteriovenous fistula (AVF) enables selective transvenous embolization (TVE) and helps to avoid hypoglossal nerve palsy. Anterior condylar AVF has a shunted pouch within the condylar vascular and osseous structures. Detailed anatomical comprehension of the shunted pouch is essential, in addition, we believe that it is important to have a strategy for where in the shunted pouch to start filling with coils. Specifically, we consider that it is important to structurally understand the more upstream location (arterial side) within the shunted pouch (called "shunted pouch entry zone"), guide the microcatheter there, and embolize from that site. Although several studies have discussed the usefulness of intraoperative cone-beam computed tomography (CBCT) for treating anterior condylar AVF, there are no studies which have mentioned the importance of microcatheter position before coil embolization in selective TVE as in this study. Intraoperative localization of the shunted pouch entry zone is often difficult. Herein, the authors report that cone-beam computed tomography (CBCT) can assist accurate microcatheter tip placement at the shunted pouch entry zone before staring embolization. This is the novel application of intraoperative CBCT to treat anterior condylar AVF successfully treated with precise and selective TVE.

Recovery from hemidiaphragmatic paralysis with improved respiratory function following cervical laminoplasty and foraminotomy: illustrative case.

BACKGROUND: Hemidiaphragmatic paralysis can occasionally be caused by cervical canal and foraminal stenosis. Rarely is the effect of surgical decompression on hemidiaphragmatic paralyzed patient respiratory function recorded. This report details a case of postoperative respiratory function restoration in a patient with cervical spondylosis-related hemidiaphragmatic paralysis. OBSERVATIONS: A 77-year-old woman suffered hemidiaphragmatic paralysis caused by cervical canal and foraminal stenosis. The phrenic nerve palsy was thought to be caused by compression of the cervical spinal cord and its nerve root. The patient received a C3 laminectomy, a C4-6 laminoplasty, and a left C3-4 and C4-5 posterior foraminotomy. After surgery, she improved her maximum inspiratory pressure and respiratory function. LESSONS: Cervical canal and foraminal stenosis may cause hemidiaphragmatic paralysis due to radiculopathy-induced phrenic nerve palsy. Laminoplasty and posterior foraminotomy can restore respiratory dysfunction related to diaphragmatic paralysis by decompressing the ventral horn of the spinal cord and spinal nerve root.

Less Invasive Management of Endovascular Embolization and Neuroendoscopic Surgery for a Dural Arteriovenous Fistula Presenting with Acute Subdural Hematoma.

Acute subdural hematoma (ASDH), which causes midline shift of the brain, rarely arises from a dural arteriovenous fistula (DAVF). Herein, we report the first case of a DAVF manifesting ASDH, which was treated less invasively with endovascular embolization of a drainer of the DAVF and hematoma removal under neuroendoscopy. A 59-year-old man with a sudden onset of headache was transported to our hospital. Left ASDH and intracerebral hematoma in the left occipital lobe were detected. A cerebral angiogram revealed a DAVF fed by the petrosquamous branch of the left middle meningeal artery and jugular branch of the right ascending pharyngeal artery. The shunting point in the lateral tentorial DAVF drains through the internal occipital vein to the superior sagittal sinus. A varix was recognized in the draining vein (Borden type 3, Cognard type 4). The DAVF was embolized with Onyx (Medtronic, Minnesota, USA), and the left ASDH was removed with a small craniotomy under neuroendoscopy. No origin of the left ASDH was apparent in the surgical field. The patient was discharged from the hospital on postoperative day 18. The patient's status was modified Rankin scale 1 on discharge. Our management of combined endovascular treatment and neuroendoscopic hematoma removal may be useful and less invasive for hemorrhagic DAVF.

Clinical Items for Geriatric Patients with Post-Stroke at Discharge or Transfer after Rehabilitation Therapy in a Chronic-Phase Hospital: A Retrospective Pilot Study.

Clinical factors related to destination after rehabilitation therapy for geriatric patients with post-stroke in chronic-phase hospitals have not been elucidated. This study analyzed the clinical characteristics of geriatric patients with post-stroke at discharge/transfer after rehabilitation therapy in a chronic-phase hospital. Fifty-three patients (20 men, 33 women; mean age 81.36 ± 8.14 years) were recruited (the period analyzed: October 2013−March 2020). Clinical data were statistically analyzed among patients discharged to homes or facilities for older adults or transferred to another hospital. In addition, we analyzed the clinical items at discharge and transfer after rehabilitation therapy using a decision tree analysis. Twelve patients were discharged, eighteen were discharged to facilities for older adults, and twenty-three were transferred to another hospital. There were significant differences in the modified Rankin Scale, admission dates, functional independence measure (FIM) score, and Barthel Index score in the three groups (p < 0.05). Patients with motor subtotal functional independence scores of ≥14 (chronologically improved ≥5) after rehabilitation therapy for <291 days were more likely to be discharged home. Patients in a chronic-phase hospital who improved within a limited period were discharged to their homes, whereas those who were bedridden tended to be transferred to another hospital.

Infratentorial developmental venous anomaly concurrent with a cavernoma and dural arteriovenous fistula.

OBJECTIVES: While developmental venous anomaly (DVA) may be associated with cavernous malformation, mixed vascular malformation associated with dural arteriovenous fistula (dAVF) has not been previously reported. We observed a case with rare association of infratentorial DVA, cavernous malformation, and dAVF that presented with cerebellar ataxia. We report our endovascular treatment for this complex cerebrovascular condition. CASE PRESENTATION: A 32-year-old woman with ataxia had an infratentorial DVA associated with a cavernoma and dAVF. The dAVF had two shunting points. The dAVF was fed by the posterior meningeal arteries and drained through the sigmoid sinus into the transverse sinus. The dAVF was also fed by the occipital artery and retrogradely drained through the left jugular bulb into the dilated collecting vein of the DVA. Endovascular embolization was performed for the dAVF and dilated collecting vein of the DVA. Postoperative complications did not occur after embolization with no recurrence for three years. CONCLUSIONS: This is the first reported case of infratentorial DVA associated with a cavernoma and dAVF. Endovascular treatment was effective in treating this symptomatic complex cerebrovascular disorder.

The bifurcation angle is associated with the progression of saccular aneurysms.

The role of the bifurcation angle in progression of saccular intracranial aneurysms (sIAs) has been undetermined. We, therefore, assessed the association of bifurcation angles with aneurysm progression using a bifurcation-type aneurysm model in rats and anterior communicating artery aneurysms in a multicenter case-control study. Aneurysm progression was defined as growth by ≥ 1 mm or rupture during observation, and controls as progression-free for 30 days in rats and ≥ 36 months in humans. In the rat model, baseline bifurcation angles were significantly wider in progressive aneurysms than in stable ones. In the case-control study, 27 and 65 patients were enrolled in the progression and control groups. Inter-observer agreement for the presence or absence of the growth was excellent (κ coefficient, 0.82; 95% CI, 0.61-1.0). Multivariate logistic regression analysis showed that wider baseline bifurcation angles were significantly associated with subsequent progressions. The odds ratio for the progression of the second (145°-179°) or third (180°-274°) tertiles compared to the first tertile (46°-143°) were 5.5 (95% CI, 1.3-35). Besides, the bifurcation angle was positively correlated with the size of aneurysms (Spearman's rho, 0.39; P = 0.00014). The present study suggests the usefulness of the bifurcation angle for predicting the progression of sIAs.

Carotid Micromesh Stent for the Cervical Carotid Artery Dissecting Aneurysm in a Patient with Vascular Eagle Syndrome.

OBJECTIVES: An elongated styloid process may cause vascular Eagle syndrome that includes cervical carotid artery (CCA) dissection with stenosis and aneurysm formation. There are only four reported cases with vascular Eagle syndrome-related CCA dissecting aneurysm treated with carotid artery stenting (CAS). This is the first report of applying a dual-layer nitinol micromesh stent (CASPER) for vascular Eagle syndrome-related CCA dissecting aneurysm. CASE PRESENTATION: A 38-year-old man presented with a sudden onset of aphasia and right hemiplegia. Cerebral angiography demonstrated the left CCA dissecting aneurysm. The superior trunk of the left middle cerebral artery (MCA) was also occluded, and emergent thrombectomy was performed. Computed tomography with angiography (CTA) revealed that a 33 mm-long styloid process compressed the CCA at the aneurysm formation. Three weeks later, a CASPER stent was applied for the CCA aneurysm under the flow reversal system. Immediately after stent placement, blood flow in the aneurysm became stagnant, and postoperative CTA demonstrated regression of the aneurysm. The aneurysm did not recur for 6 months with no styloid process resection. CONCLUSIONS: The dual-layer nitinol micromesh stent (CASPER) was useful to treat vascular Eagle syndrome-related CCA dissecting aneurysm.

Correlation of Scoring Systems with the Requirement of an External Ventricular Drain in Intraventricular Hemorrhage.

BACKGROUND: External ventricular drainage (EVD) is required to resolve acute hydrocephalus associated with intraventricular hemorrhage (IVH). The correlation of scoring systems of IVH with indications for EVD for acute hydrocephalus related to IVH is currently unknown. METHODS: We identified 213 hypertensive patients with IVH and divided them into 2 groups according to treatment method: 187 patients receiving blood pressure control alone and 26 patients undergoing EVD. The following patients were excluded: pediatric patients, patients undergoing intracranial hematoma removal, patients with fetal status, and patients without sufficient clinical data. We compared the Glasgow Coma Scale score, Graeb score, LeRoux score, Evans index, and bicaudate index values between the 2 groups and determined the prognostication accuracy of each scoring system. RESULTS: There were significant differences in all 4 scoring systems between the 2 groups (P < 0.001). The cutoff values (sensitivity and specificity) of each scoring system were as follows: Glasgow Coma Scale, 8 (65.4%, 87.7%); Graeb score, 6 (80.8%, 75.4%); LeRoux score, 9 (80.8%, 76.5%); Evans index, 0.245 (80.8%, 67.9%); and bicaudate index, 0.186 (76.9%, 76.5%). The value of the area under the curve of each scoring system (95% confidence interval) was as follows: Glasgow Coma Scale, 0.806 (0.705-0.907); Graeb score, 0.852 (0.779-0.925); LeRoux score, 0.875 (0.812-0.937); Evans index, 0.788 (0.702-0.875); and bicaudate index, 0.778 (0.673-0.883). CONCLUSIONS: The LeRoux score is better for identifying patients with IVH who are more likely to have EVD.

Incidence and clinical characteristics of spinal arteriovenous shunts: hospital-based surveillance in Okayama, Japan.

OBJECTIVE: There have been no accurate surveillance data regarding the incidence rate of spinal arteriovenous shunts (SAVSs). Here, the authors investigate the epidemiology and clinical characteristics of SAVSs. METHODS: The authors conducted multicenter hospital-based surveillance as an inventory survey at 8 core hospitals in Okayama Prefecture between April 1, 2009, and March 31, 2019. Consecutive patients who lived in Okayama and were diagnosed with SAVSs on angiographic studies were enrolled. The clinical characteristics and the incidence rates of each form of SAVS and the differences between SAVSs at different spinal levels were analyzed. RESULTS: The authors identified a total of 45 patients with SAVSs, including 2 cases of spinal arteriovenous malformation, 5 cases of perimedullary arteriovenous fistula (AVF), 31 cases of spinal dural AVF (SDAVF), and 7 cases of spinal epidural AVF (SEAVF). The crude incidence rate was 0.234 per 100,000 person-years for all SAVSs including those at the craniocervical junction (CCJ) level. The incidence rate of SDAVF and SEAVF combined increased with advancing age in men only. In a comparative analysis between upper and lower spinal SDAVF/SEAVF, hemorrhage occurred in 7/14 cases (50%) at the CCJ/cervical level and in 0/24 cases (0%) at the thoracolumbar level (p = 0.0003). Venous congestion appeared in 1/14 cases (7%) at the CCJ/cervical level and in 23/24 cases (96%) at the thoracolumbar level (p < 0.0001). CONCLUSIONS: The authors reported detailed incidence rates of SAVSs in Japan. There were some differences in clinical characteristics of SAVSs in the upper spinal levels and those in the lower spinal levels.

Subjective and objective evaluation of swallowing in lateral decubitus positions examined in healthy volunteers.

BACKGROUND: Dysphagia can result from shock, trauma, aging, head and neck neoplasms, and some cerebrovascular diseases or neuromotor degenerative disorders. Swallowing rehabilitation therapy combined with postural control of the neck, head, and body can be effective for patients with dysphagia. Though the lateral decubitus posture has been a favorable option for swallowing rehabilitation therapy, available clinical data pertaining to it are scarce. METHODS: Twenty-seven healthy volunteers were enrolled in this study. The subjects underwent a repetitive saliva swallowing test, food swallowing test, and water swallowing test. The trials were performed in four different positions: upright sitting position, lateral decubitus position with the head raised to 60°, lateral decubitus position with the head raised to 30°, and complete lateral decubitus position. After each trial, the subjects were asked to declare the swallowing difficulty utilizing a visual analogue scale. Swallowing time and swallowing sound level were recorded simultaneously, as objective evaluation in each trial. We analyzed the visual analogue scale scores, swallowing time, and swallowing sound levels for all the four positions. RESULTS: The results of the visual analogue scale of the water swallowing test in the sitting position were significantly lower than those of the complete lateral decubitus position (p < 0.01). However, statistical significance was not detected in swallowing time or the swallowing sound level among the four different positions. Although subjective discomfort in swallowing was identified, difficulty of swallowing was not objectively evident in the trials, irrespective of the position. CONCLUSIONS: A complete lateral decubitus position can be an effective and safe position in swallowing.