Analysis of the clinical characteristics of V4 segment steal blood in the vertebral artery / 中华内科杂志

Objective:To explore the clinical characteristics of unilateral vertebral artery V4 segment occlusive lesions (severe stenosis or occlusion), where the contralateral vertebral artery can be compensated through blood flow and reverse supply to the posterior inferior cerebellarartery (PICA).Methods:This study is a retrospective case series of 66 patients with V4 segment occlusive lesions of unilateral vertebral artery diagnosed and treated from June 2020 to October 2022. Patient data were retrospectively collected, and their hemodynamic characteristics and imaging data were analyzed.Results:Of the 66 cases, 11 patients (16.7%) with V4 segment occlusive disease showed the blood flow of the vertebral artery on the opposite side of the lesion on the digital subtraction angiography (DSA), which can be reverse stolen to the posterior inferior cerebellar artery of the diseased side through the confluence point of the vertebrobasilar artery through the distal end of the ipsilateral vertebral artery V4. Owing to the lack of literature on this pathway and based on the characteristics of previous definitions of subclavian artery steal and carotid artery steal, we referred to this pathway as the vertebral artery V4 segment steal. In 6 patients (9.1%), transcranial Doppler ultrasound (TCD) and transcranial color Doppler ultrasound (TCCD) showed that the blood flow signal was not detected at the proximal end of the V4 segment of the affected side, rather the blood flow direction was reversed at the distal end of the V4 segment, resulting in compensatory acceleration of the blood flow velocity of the V4 segment of the contralateral vertebral artery.Conclusion:“V4 segment steal of vertebral artery” is a very rare route of vertebral artery steal. When V4 segment of the vertebral artery is occluded, clinicians should pay attention to observe the blood supply of PICA and whether there is such a steal route, to better evaluate the blood flow compensation and prognosis of patients.

Estudio de la prevalencia del nacimiento y de la presencia de bucle caudal extracraneano de arterias cerebelosas posteroinferiores en una población estudiada por angiografía cerebral / Study of the prevalence of origin and the presence of an extracranial caudal loop of the posterior inferior cerebellar arteries in a population studied by cerebral angiography

Introducción. La arteria cerebelosa posteroinferior (ACPI) nace de la arteria vertebral en la cara anterolateral del tronco cerebral, generalmente a la altura de la oliva inferior, transcurriendo en forma rostral a través de las raíces de los nervios glosofaríngeo, vago y accesorio. El objetivo del trabajo es determinar la prevalencia del nacimiento de la arteria cerebelosa postero inferior a nivel extracraneano, la presencia de bucle caudal extracraneano y las relaciones con estructuras oseas adyacentes, en una población estudiada por angiografía de vasos supraaórticos. Material y métodos. Estudio prospectivo, descriptivo, de una muestra consecutiva realizada durante un año (septiembre 2021 a agosto 2022) de todos los pacientes a los que se les realizó un cateterismo de vasos de cuello y cerebrales en Neurointervencionismo del Hospital de Alta Complejidad en Red "El Cruce", Buenos Aires, Argentina.Los estudios se realizaron en dos angiógrafos digitales en forma indistinta en incidencia perfil, con y sin digitalización de imagen, focalizadas en la unión craneo-cervical en todos los pacientes estudiados entre 18 y 80 años. Se objetivó el lugar de nacimiento de las arterias ACPI y la presencia de bucles extracraneanos por visión directa en los estudios sin y con sustracción. Se definió como bucle o loop extracraneano a la presencia de un segmento curvo de la arteria con dirección caudal que se extiende por debajo del foramen magno. Se buscó la concordancia interobservador entre 2 profesionales en forma independiente. Resultados. De los 404 procedimientos realizados en el período estudiado ingresaron 288 pacientes al estudio, de los cuales 152 fueron mujeres. La edad promedio fue de 49,2 años. Se analizaron 422 ACPI, 214 derechas y 208 izquierdas. Se observaron un total de 102 ACPI con bucles extracraneanos, representando un 24,1% del total: 49 derechos (48%) y 53 izquierdos (52%). En relación a arterias con origen extracraneal, se observaron en total 58 (13,7%) de las cuales 29 fueron derechas (50%). En 10 casos se observó en la misma arteria nacimiento y loop extracraneano (10%) y en dos casos nacimiento y loop extracraneano bilateral (3.9%). En 13 casos la arteria vertebral fue terminal en ACPI, de las cuales 5 presentaron un loop extracraneano, representando el 38,5 % de su población, siendo en su totalidad del territorio derecho. Conclusión. La prevalencia del nacimiento extracraneano de la ACPI en la población estudiada por angiografía fue de 13,7% y la prevalencia de bucle extracraneano fue del 24%. Ambos porcentajes se encuentran dentro de los resultados hallados en estudios previos, anatómicos y por imágenes: 0,7 al 20% y 9,5 al 35% respectivamente. La prevalencia de bucle extracraneano en arterias vertebrales con terminación en ACPI fue del 38,5%, siendo significativamente superior a los estudios reportados

Background. The posteroinferior cerebellar artery (PICA) arises from the vertebral artery on the anterolateral aspect of the brain stem, generally at the level of the inferior olive, running rostrally through the roots of the glossopharyngeal, vagus and accessory nerves. The objective of the work is to determine the prevalence of the origin of the posterior inferior cerebellar artery at the extracranial level, the presence of an extracranial caudal loop and the relationships with adjacent bone structures, in a population studied by angiography of supra-aortic vessels. Methods. Prospective, descriptive study of a consecutive sample carried out for one year (September 2021 to August 2022) of all patients who underwent catheterization of neck and cerebral vessels in the "Hospital de Alta Complejidad en Red El Cruce", Buenos Aires, Argentina. The studies were carried out in two digital angiographers indistinctly in profile incidence, with and without image digitization, focused on the cranio-cervical junction in all patients studied between 18 and 80 years of age. The birthplace of the ACPI arteries and the presence of extracranial loops were observed by direct vision in the studies without and with subtraction. An extracranial loop was defined as the presence of a curved segment of the artery with a caudal direction that extends below the foramen magnum. Interobserver agreement was sought between 2 professionals independently. Results. Of the 404 procedures performed in the studied period, 288 patients entered the study, of which 152 were women. The average age was 49,2 years; 422 PICA were analyzed, 214 right and 208 left. A total of 102 PICA with extracranial loops were observed, representing 24.1% of the total: 49 right (48%) and 53 left (52%). In relation to arteries with extracranial origin, a total of 58 (13.7%) were observed, of which 29 were right (50%). In 10 cases birth and extracranial loop were observed in the same artery (10%) and in two cases birth and bilateral extracranial loop (3.9%). In 13 cases the vertebral artery was terminal in PICA, of which 5 presented an extracranial loop, representing 38.5% of its population, being entirely in the right territory. Conclusions. The prevalence of extracranial origin of the PICA in the population studied by angiography was 13.7% and the prevalence of extracranial loop was 24%. Both percentages are within the results found in previous anatomical and imaging studies: 0.7 to 20% and 9.5 to 35% respectively. The prevalence of extracranial loop in vertebral arteries ending in PICA was 38.5%, being significantly higher than the reported studies

Clinical differences and related factors of Wallenberg syndrome / 中风与神经疾病杂志

@#Objective　To explore the reasons for differences in the clinical manifestations of Wallenberg syndrome，and provid valuable information for clinical work. Methods　A retrospective analysis of 41 cases of Wallenberg syndrome clinical and imaging data. Our patients were grouped according to age，risk factors and vascular lesions. The clinical differences were studied in each group of patients. Results　The most common clinical symptoms and signs of Wallenberg syndrome was vertigo and dizziness，followed dysarthria，ataxia，sensory disturbances，gag reflex diminished or disappeared，difficulty swallowing，nausea or vomiting，Horner syndrome，nystagmus. Age and clinical symptom scores were negatively correlated （P=0.002）. Hypertension，diabetes，hyperlipidemia，and smoking in patients with clinical manifestations were no significant correlation. The vertebral artery and vertebral artery combined cerebellar artery disease patients were statistically significant different with pure posterior inferior cerebellar artery disease patients in the emergence of dysarthria （P=0.029），nausea/vomiting（P=0.033） and dysphagia（P=0.002）. Conclusion　Clinical manifestations of Wallenberg syndrome are varied. Age and clinical symptom scores were negatively correlated. Vertebral artery and vertebral artery joint cerebellar artery disease more easily lead to dysarthria，dysphagia，and nausea/vomiting.

Posterior Inferior Cerebellar Artery Infarction Originating at C1-2 after C1-2 Fusion / 대한신경손상학회지

Vertebral artery injuries associated with C1 lateral mass screw insertion rarely occur during C1-2 fusion. The posterior inferior cerebellar artery (PICA) is uncommonly located at the C1 lateral mass insertion position. A 71-year-old woman with atlanto-axial subluxation and cord compression underwent C1-2 fusion. Sixth nerve palsy and diplopia were detected postoperatively, and decreased consciousness occurred on postoperative day 4. Brain magnetic resonance image (MRI) and computed tomography (CT) revealed PICA infarction. In the preoperative CT angiography, the PICA originated between the C1 and C2 level. In the postoperative CT scan, the PICA was not visible. The patient was treated conservatively for two weeks and recovered. PICA originating between the C1 and C2 level comprises 1.1–1.3% of cases. Therefore, vertebral artery anomalies should be evaluated prior to C1-2 fusion to prevent vessel injuries.

Variations In Posterior Inferior Cerebellar Artery And Its Clinical Significance In Uttar Pradesh Region: A 64-slice Ct Angiographic Study

Background: Posterior Inferior cerebellar artery (PICA) is the largest and most distal branch of Vertebral artery(VA) arising near the lower end of olive. Variations of PICA are numerous but have been infrequently reported inthis region. Occlusion or blockage of PICA may cause an infarction of the medulla oblongata which plays animportant role in circulatory and respiratory functioning. This may lead to lateral medullary syndrome, alsocalled Wallenberg syndrome. The study focuses on normal and variant anatomy of PICA in Uttar Pradesh regionof North India.Materials and Methods: The study population included 100 subjects, of either sex, who underwent Head and NeckCT Angiography in the Department of Radiodiagnosis, King George’s Medical College, Lucknow, Uttar Pradesh. Thediameters of PICAs of both sides were measured and variations encountered were noted.Results: Mean diameter of PICA was 1.76±0.64 mm on right side and 1.73±0.60 mm on left side. Mean diameter inmales was 1.75±0.62 mm and in females was 1.73±0.62 mm. Variations observed included: Unilateral aplasia ofPICA in 16% with equal prevalence on both sides; bilateral aplasia in 3% cases; hypoplasia of RPICA in10% andhypoplasia of LPICA in 6%. VA-PICA variation where the VA continued as posterior inferior cerebellar artery wasobserved in 8 subjects (4 right, 4 left).Conclusion: The knowledge of normal diameters and variations in PICA supplying the brain can be a useful guideto the surgeons and interventional radiologists for careful pre-operative planning thus helping them in avoidingpotentially life threatening complications.

Technical Consideration for Coiling of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm

OBJECTIVE: Surgical obliteration of ruptured aneurysm of the proximal posterior inferior cerebellar artery (PICA) is challenging because of limited surgical accessibility. In recent years, coil embolization is the first-choice treatment for these lesions. However, coil embolization is not always easy in ruptured PICA aneurysm owing to the variable anatomical diversity of its shapes, its relationship to the parent artery, its low incidence, and accordingly, lesser neurointerventionist experience. METHODS: The parent artery and microcatheter for easier navigation and the embolization technique for stable coiling were identified. RESULTS: This study aimed to identify the more appropriate approach route, microcatheter, and strategies for an easier and safer, and more durable coil embolization in the treatment of lesions in the proximal PICA. CONCLUSION: Coil embolization for aneurysmal subarachnoid hemorrhage due to a ruptured proximal PICA remains a challenge, but with the appropriate coiling plan, it can be treated successfully.

Technical Consideration for Coiling of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm

OBJECTIVE: Surgical obliteration of ruptured aneurysm of the proximal posterior inferior cerebellar artery (PICA) is challenging because of limited surgical accessibility. In recent years, coil embolization is the first-choice treatment for these lesions. However, coil embolization is not always easy in ruptured PICA aneurysm owing to the variable anatomical diversity of its shapes, its relationship to the parent artery, its low incidence, and accordingly, lesser neurointerventionist experience.METHODS: The parent artery and microcatheter for easier navigation and the embolization technique for stable coiling were identified.RESULTS: This study aimed to identify the more appropriate approach route, microcatheter, and strategies for an easier and safer, and more durable coil embolization in the treatment of lesions in the proximal PICA.CONCLUSION: Coil embolization for aneurysmal subarachnoid hemorrhage due to a ruptured proximal PICA remains a challenge, but with the appropriate coiling plan, it can be treated successfully.

Endovascular treatment of vertebral artery dissecting aneurysm involving posterior inferior cerebellar artery / 中国脑血管病杂志

Objective To analyze stenting and dual catheter technique in protection of posterior inferior cerebellar artery and its imaging and clinical follow-up results in the endovascular treatment of vertebral artery dissecting aneurysms. Methods From January 2012 to December 2014,the clinical data of 4 patients with vertebral artery dissecting aneurysm involving posterior inferior cerebellar artery treated with endovascular method and admitted to the Department of Neurosurgery,Xuanwu Hospital,Capital Medical University were enrolled retrospectively. The whole brain DSA examinations were performed at 6 months after procedure. The clinical follow-up period ranged from 12 to 24 months. Results Three of the 4 patients were treated with posterior inferior cerebellar artery-vertebral artery stenting,one patient was treated by using bidirectional dual catheter technique to protect posterior inferior cerebellar artery. The interventional therapy of 4 patients were all successful. Immediately after procedure,angiography revealed that the posterior inferior cerebellar arteries were patent,no ischemic symptoms were observed. The angiography at 6 months after procedure revealed no recurrence of aneurysms;the posterior inferior cerebellar arteries were patent without in-stent stenosis. No new symptoms of neurological deficit were observed during 12 to 24-month follow-up. Conclusion In the interventional treatment of vertebral artery dissecting aneurysms of posterior inferior cerebellar artery,using the posterior inferior cerebellar artery-vertebral artery stenting technique and bidirectional dual catheter technique may safely and effectively protect the posterior inferior cerebellar artery.

In Situ Intersegmental Anastomosis within a Single Artery for Treatment of an Aneurysm at the Posterior Inferior Cerebellar Artery: Closing Omega Bypass

A 74-year-old patient was diagnosed with a subarachnoid hemorrhage suspected from a dissecting aneurysm located at the lateral medullary segment of the posterior inferior cerebellar artery (PICA). Because perforators to the medulla arose both proximal and distal to the dissecting segment, revascularization for distal flow was essential. However, several previously reported methods for anastomosis, such as an occipital artery-PICA bypass or resection with PICA end-to-end anastomosis could not be used. Ultimately, we performed an in situ side-to-side anastomosis of the proximal loop of the PICA with distal caudal loops within a single artery, as a "closing omega," followed by trapping of the dissected segment. The aneurysm was obliterated successfully, with intact patency of the revascularized PICA.

Endovascular Treatment of a Ruptured Posterior Inferior Cerebellar Artery Aneurysm during Pregnancy

Aneurysmal subarachnoid hemorrhage (SAH) during pregnancy is quite rare, however it has a high maternal mortality rate. A pregnant woman in the 16th gestational week was admitted to our hospital with a drowsy level of consciousness. A brain magnetic resonance (MR) image showed hemorrhage on the prepontine cistern, and both sylvian fissures, and MR angiography and cerebral digital subtraction angiography demonstrated an aneurysm at the left posterior inferior cerebellar artery (PICA). We performed endovascular coil embolization attempting to minimize radiation exposure. She was discharged with no neurologic deficit and delivered a healthy baby by cesarean section at the 38th week of gestation. This case study reported the shortest gestational period and this is the first report on an aneurysmal rupture arising from PICA which was treated using an endovascular method. Using an appropriate technique for reduced radiation exposure to the fetus and limited alterations in maternal-fetal physiology, endovascular coil embolization could guarantee good results in treatment of aneurysmal SAH in pregnant women.

High-Resolution Contrast-Enhanced 3D-Spoiled Gradient-Recalled Imaging for Evaluation of Intracranial Vertebral Artery and Posterior Inferior Cerebellar Artery in Lateral Medullary Infarction

PURPOSE: To determine whether high-resolution contrast-enhanced three dimensional imaging with spoiled gradient-recalled sequence (HR-CE 3D-SPGR) plays a meaningful role in the assessment of intracranial vertebral artery (ICVA) and posterior inferior cerebellar artery (PICA) in lateral medullary infarction (LMI). MATERIALS AND METHODS: Twenty-five patients confirmed with LMI were retrospectively enrolled with approval by the IRB of our institute, and 3T MRI with HR-CE 3D-SPGR and contrast-enhanced magnetic resonance angiography (CE-MRA) were performed. Two radiologists who were blinded to clinical information and other brain MR images including diffusion weighted image independently evaluated arterial lesions in ICVA and PICA. The demographic characteristics, the area of LMI and cerebellar involvement were analyzed and compared between patients with arterial lesion in ICVA only and patients with arterial lesions in both ICVA and PICA on HR-CE 3D-SPGR. RESULTS: Twenty-two of twenty-five LMI patients had arterial lesions in ICVA or PICA on HR-CE 3D SPGR. However twelve arterial lesions in PICA were not shown on CE-MRA. Concurrent cerebellar involvement appeared more in LMI patients with arterial lesion in ICVA and PICA than those with arterial lesion in ICVA alone (p = 0.069). CONCLUSION: HR-CE 3D-SPGR can help evaluate arterial lesions in ICVA and PICA for LMI patients.

Diagnosis value of CTA on posterior inferior cerebellar artery aneurysm(report of 2 cases) / 临床神经病学杂志

Objective To explore the diagnosis value of CTA on posterior inferior cerebellar artery ( PICA ) aneurysm.Methods The clinical data of 2 patients with PICA aneurysms were analyzed retrospectively .Results Two patients were elderly,acute onset,CT confirmed subarachnoid hemorrhage ,CTA of the first time were negative within 3 h after the onset .After the treatments of preventing cerebral vasospasm , increasing blood volume , protecting brain cells and etc for 3-7 d, one case improved ,one case were invalid .Given CTA examination again then found 3 aneurysms, one case with 2 aneurysms located on the left side of the PICA , accompanying with hydrocephalus ,and the other case with 1 aneurysm located on the left side of the PICA .Two patients obtained a good image evaluation and rich information .Conclusions In view of the particularity of the PICA aneurysms , CTA can be used as the preferred method of examination , which can provide comprehensive imaging data .When CTA examination of the first time is negative , giving CTA again remains an ideal choice after short-term treatment .

Retrograde Stent Placement for Coil Embolization of a Wide-Necked Posterior Inferior Cerebellar Artery Aneurysm

Wide-necked aneurysms of the posterior inferior cerebellar artery (PICA) are infrequently encountered in cerebrovascular practice, and endovascular treatment is difficult or impossible even with the use of several neck remodeling techniques. We present the case of a patient with a wide-necked aneurysm of the PICA, which was treated by the retrograde stenting through the contralateral vertebral artery and vertebrobasilar junction with antegrade coil embolization.

Dissecting Aneurysm Associated with a Double Origin of the Posterior Inferior Cerebellar Artery Causing Subarachnoid Hemorrhage

Two cases of the posterior fossa dissecting aneurysm associated with a double origin of the posterior inferior cerebellar artery (DOPICA) causing subarachnoid hemorrhage are presented. After observing a relationship between the aneurysm and DOPICA on a three dimensional rotational angiogram (3DRA), the dissecting aneurysms were successfully obliterated by surgical trapping and endovascular internal trapping, respectively. This report warrants suspecting DOPICA of an associating anomaly predisposing to dissecting aneurysm in the vertebral artery-posterior inferior cerebellar artery territory and highlights the role of 3DRA in pretreatment evaluation of unusual aneurysms accompanying a particular anatomical variation.

Simultaneous Vertebral Artery Dissection and Contralateral Posterior Inferior Cerebellar Artery Dissecting Aneurysm

The optimal treatment and appropriate follow-up period for an unruptured vertebral artery (VA) and/or posterior inferior cerebellar artery (PICA) dissection have not been established. Decisions regarding treatment of these vascular lesions are usually based on the manifesting symptoms and changes in radiologic findings during the follow-up period. We experienced a patient who had a simultaneous unruptured VA dissection and a contralateral PICA dissecting aneurysm. We did not find such a case in other literature.

Bilateral Approach for Stent-assisted Coiling of Posterior Inferior Cerebellar Artery Aneurysms: Two Cases

Aneurysms of the posterior inferior cerebellar artery (PICA) are rarely encountered. In particular, due to frequent anatomic complexity and the presence of nearby critical structures, PICA origin aneurysms are difficult to treat. However, recent reports of anecdotal cases using advanced endovascular instruments and skills have made the results of endovascular treatment rather outstanding. PICA preservation is the key to a successful endovascular treatment, based on the premise that a PICA origin aneurysm is well occluded. To secure PICA flow, stenting into the PICA would be the best method, however, it is nearly impossible technically via the ipsilateral vertebral artery (VA) if the PICA arose at an acute angle from the sac. In such a case, a bilateral approach for stent-assisted coiling can be a creative method for achievement of two goals of both aneurysm occlusion and PICA preservation: ipsilateral approach for coil delivery and contralateral cross-over approach for stent delivery via a retrograde smooth path into the PICA.

Resection of the fourth ventricle tumors through lateral wall type of the cerebellomedullary fissure approach under endoscope / 中华显微外科杂志

Objective To investigate the therapeutic effect of the fourth ventricle tumors through lateral wall type of the transcerebellomedullary fissure approach under endoscope.Methods Clinical data of 14 cases with the fourth ventricle lesions were analyzed retrospectively.All the patients were treated by lateral wall type of the transcerebellomedullary fissure approach surgery.The endoscope was used if the lesions develop to the aqueduct and hard to be exposed.Both neurophysiological monitoring and intraoperative ultrasound were used regularly.Results Tumors were totally removed in 12 cases,subtotally in 1,and partially in 1.All the patients were diagnosed in postoperative histopathology,including 4 medulloblastoma,three epidermoid cyst,two ependymoma,two hemangioblastoma,one meningioma,one cavernous hemangioma and 1 astrocytoma.Hypopnea occurred immediate after operation in 1 patient.Ventilatory support was performed by Ventilator,and the respiration was restored 1 day later.Normal cerebrospinal fluid circulation was return in all cases.Neither aggravation of preoperative symptoms nor nuclei injury related complication had been found.The follow-up interval between 3 months to 28 months,one patient was dead with unexplained,and 1 medulloblastoma patient was relapse.Conclusion Lateral wall type of the transeerebellomedullary fissure approach,under endoscope,combined with the usage of neurophysiological monitoring and intraoperative ultrasound,can degrade the surgical related complications such as facial palsy and amblyacousia.

The application of the endovascular distal parent artery occlusion in vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery / 中国医师进修杂志

Objective To investigate the application of endovascular distal parent artery occlusion in vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery.Methods The clinical and follow-up data of 5 patients with vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery who received the endovascular distal parent artery occlusion were retrospectively analyzed.Results Complete occlusion of dissected arterial and aneurysm segments was achieved in 4 patients.After followed up 6-12 months,angiography showed no recurrence or neurological deficit.Continued filling of the dissected aneurysm was observed in 1 patient's follow-up angiography,but without rehaemorrhagia or neurological deficit.Conclusions The endovascular distal parent artery occlusion is a safe and efficient choice for treating vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery,which keeps the posterior inferior cerebellar artery flowing unobstructed while clipping the dissecting aneurysm.

Predicting Factors Affecting Clinical Outcomes for Saccular Aneurysms of Posterior Inferior Cerebellar Artery with Subarachnoid Hemorrhage

OBJECTIVE: The aim of this study is to investigate the clinical outcomes of surgery and coiling and analyze the predicting factors affecting the clinical outcomes of ruptured posterior inferior cerebellar artery (PICA) aneurysms. METHODS: During the last 15 years, 20 consecutive patients with ruptured PICA aneurysms were treated and these patients were included in this study. The Fisher's exact test was used for the statistical significance of Glasgow Outcome Scale (GOS) according to initial Hunt-Hess (H-H) grade, treatment modalities, and the presence of acute hydrocephalus. RESULTS: Eleven (55%) and nine (45%) patients were treated with surgical clipping and endovascular treatment, respectively. Among 20 patients, thirteen (65.0%) patients had good outcomes (GOS 4 or 5). There was the statistical significance between initial poor H-H grade, the presence of acute hydrocephalus and poor GOS. CONCLUSION: In our study, we suggest that initial H-H grade and the presence of acute hydrocephalus may affect the clinical outcome rather than treatment modalities in the ruptured PICA aneurysms.

Microanatomy of intracranial segment of vertebral artery and its main branches in surgery adopt far lateral approach / 中华神经医学杂志

Objective To discuss how to protect the intracranial vertebral artery and posterior inferior cerebellar artery by observing and measuring the intracranial vertebral artery in the surgery adopt far lateral approach. Methods Mimicking far lateral approach, 20 adult cadaveric heads connected to neck fixed with 10% formalin were dissected. Intracranial segment of the vertebral arteries and their main branches were exposed and measured under operating microscope. Results The intracranial vertebral artery joined with the contralateral one into the basilar artery after traveling through the atlanto-occipital sulcus. The relationship between the vertebral artery and the hypoglossal nerve is close. Thirty sides (75%) of the vertebral arteries traveled to pons medulla sulcus in front of the hypoglossal nerve roots and 2 sides (5%) behind the hypoglossal nerve roots, while 8 sides (20%) traveled among the hypoglossal nerve roots; 70% of the vertebral arteries were contacted to the hypoglossal nerve roots, 30% of which compressed the hypoglossal nerve. The main branches of intracranial segment of the vertebral arteries were the posterior inferior cerebellar arteries, the anterior spinal arteries, the posterior meningeal arteries,and some perforating arteries. Posterior inferior cerebellar arteries all originated from the intracranial vertebral artery were the largest vertebral artery's branches; their trip was mostly loop-shaped and they had close relationship with Ⅸ, Ⅹ, Ⅺ cranial nerves. The starting points of the posterior inferior cerebellar arteries were different, even in the same specimen, but most of them originated from the upper 1/3intracranial vertebral artery. No anterior inferior cerebellar artery was noted originated from the vertebral artery in our specimen. Anterior spinal arteries originated from the vertebral arteries joined with the branches of the bilateral vertebral arteries and traveled down through the tortuous anterior median fissure to supply the spinal cord. Conclusion Being familiar with the characteristics and anatomic vertebral arteries variations of the intracranial vertebral artery and its branches can contribute to identify and protect the intracranial segment of the vertebral artery and its main branches in the surgery adopt far-lateral approach.