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.

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 .

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.

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.

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.

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.

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.

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.

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.

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.

Detachable Coil Embolization for Saccular Posterior Inferior Cerebellar Artery Aneurysms

OBJECTIVE: Surgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging due to limited surgical accessibility. Endovascular approach has a benefit of avoiding direct injury to the brainstem or lower cranial nerves. Therefore, it has recently been considered an alternative or primary modality for PICA aneurysms. We retrospectively assessed outcomes following detachable coil embolization of saccular PICA aneurysms. METHODS: From February 1997 to December 2007, we performed endovascular procedures to treat 15 patients with 15 PICA aneurysms. Fourteen patients with 14 PICA aneurysms morphology of which was saccular were reviewed retrospectively. Twelve patients had ruptured aneurysms. The aneurysms arose from the PICA origin site (n = 12), the PICA lateral medullary segment (n = 1), or the PICA tonsilomedullary segment (n = 1). RESULTS: Complete aneurysm occlusion was achieved in 10 patients, residual neck in 3, and residual sac in one. Radiological follow-up was performed in 7 patients with mean duration of 34.7 months (range, 1-97 months) and showed stable or complete occlusion in 6 patients. There were no rebleeding or retreatment after endovascular treatment. Thromboembolism was the only procedure-related complication (n = 4 ; 28.6%). Asymptomatic PICA infarction occurred in two patients and symptomatic PICA infarction in two elderly patients with poor clinical grade. Of these procedural PICA infarction cases, 1 symptomatic PICA infarction patient developed ventriculitis and septic shock leading to death. The clinical outcome was good in 10 patients (71.4%). Conclusions: In the present study, detachable coil embolization has shown as an efficient modality for PICA saccular aneurysms challenging indications of microsurgery. However, thromboembolic complications should be considered, especially in poor clinical elderly patients with ruptured aneurysms.

The Clinical Presentation and Treatment of Distal Posterior Inferior Cerebellar artery Aneurysms: Report on 2 cases / 대한뇌혈관외과학회지

Aneurysms arising from the posterior inferior cerebellar artery (PICA) are uncommon, with a reported incidence ranging between 0.5 and 2% of all the aneurysms in the brain. Most of them arise at the PICA origin from the vertebral artery, whereas distal PICA aneurysms are exceptional. We have experienced two consecutive cases of distal PICA aneurysms. Both patients were female and the first patient was 48 years old and the second patient was 60 years old. Cerebral angiography was performed immediately after admission and it showed an aneurysm located on the distal PICA. One patient was treated by a combined endovascular and surgical approach, and the other patient was treated by a surgical approach only. The former patient expired 8 days from the ictus. The latter patient had a good outcome during admission. Distal PICA aneurysms are exceptionally rare and they may be successfully treated with surgical or endovascular techniques. The therapeutic strategy, either surgical or endovascular, should be selected according to the condition of the patient and the arterial and aneurysmal morphology.

The Endovascular Management of Saccular Posterior Inferior Cerebellar Artery Aneurysms

OBJECTIVE: The purpose of this retrospective study was to report the outcome of the endovascular treatment of eight patients with eight saccular posterior inferior cerebellar artery (PICA) aneurysms. MATERIALS AND METHODS: Over the last seven years (1999-2006), eight consecutive patients with saccular PICA aneurysms were treated by endovascular methods. Five of the aneurysms were presented with subarachnoid hemorrhaging, whereas three were discovered incidentally. Four of the aneurysms (3 ruptured and 1 incidental) were treated by intrasaccular coiling, whereas the remaining four (1 ruptured and 3 incidental) were treated by vertebral artery (VA) occlusion. RESULTS: Of the four aneurysms treated by intrasaccular coiling, three were completely packed with coils and one was partially packed. In three of four patients who underwent vertebral artery occlusions, follow-up digital subtraction angiographies demonstrated thrombosed aneurysms and PICA. No procedure-related morbidity occurred and no re-bleed was encountered during a follow-up examination (mean; 31 months). CONCLUSION: As a result of this study, we found that the endovascular management of saccular PICA aneurysms should be considered as safe and effective.

Aneurysms of Distal Posterior Inferior Cerebellar Artery

OBJECTIVE: Aneurysms are very rarely encountered in the distal posterior inferior cerebellar artery (PICA). The authors experienced 5 cases with a distal PICA aneurysm among 368 cases of intracranial aneurysms during the period from January 2003 to January 2008. Here, the authors describe their clinical and surgical experiences and include a review of the relevant literature. METHODS: Using radiologic findings and charts, we retrospectively reviewed the surgical results of 5 cases with a distal PICA aneurysm treated from January 2003 to January 2008. RESULTS: The current five cases were composed of four cases of 'Good' and one case of 'Fair'. No postoperative complications occurred other than a ventriculo-peritoneal shunt due to hydrocephalus in Case 2. In all five cases, treatment was successful without neurological deficit. CONCLUSION: Surgical outcome of PICA aneurysms have been reported to be excellent because the amount of intraparenchymal injury is limited. More clinical experience, microsurgical technique developments, and endovascular surgery advancements are certain to improve treatment outcomes.