Vertebral Artery-posterior Inferior Cerebellar Artery Research Articles

Far-lateral approach without C1 laminectomy for microsurgical treatment of vertebral artery and proximal posterior inferior cerebellar artery aneurysms: Experience from 48 patients

BackgroundIn the endovascular era, most of vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms were mainly treated with endovascular procedures. This study aimed to demonstrate the microsurgical treatment via the far-lateral approach without C1 laminectomy and its clinical outcomes. MethodsForty-eight patients with VA and proximal PICA aneurysms treated by microsurgery through the far-lateral approach without C1 laminectomy, between January 2016 and June 2021, were retrospectively evaluated. ResultsMost patients (87.5%) presented with subarachnoid hemorrhage. Grading at presentation was poor in 41.7%. The rates of VA dissecting aneurysms, saccular aneurysms of the VA–PICA junction, and true PICA saccular aneurysms were 54.2, 18.7, and 14.6%, respectively. All aneurysms were located above the lower margin of the foramen magnum. The far-lateral approach without C1 laminectomy was successfully used in all patients without residual aneurysms. Various surgical strategies were applied depending on the characteristics of the aneurysm. Good outcomes 3 months postoperatively were achieved in 77.1% and 89.3% for the overall and good-grade groups, respectively. ConclusionsMicrosurgery is a safe and effective treatment of VA and proximal PICA aneurysms. Moreover, the far-lateral approach without C1 laminectomy was adequate and effective for aneurysms located above the lower border of the foramen magnum.

Staged treatment for ruptured wide-neck intracranial aneurysm with intentional partial coiling in the acute phase followed by definitive treatment.

Background: Evidence supports endovascular coiling for ruptured intracranial aneurysms (RIAs). However, in some cases, it is difficult to achieve complete occlusion by coiling, such as with wide-neck aneurysms. We report our experience with intentional staged RIA treatment using targeted endovascular coiling at the rupture point in the acute phase, followed by delayed stent-assisted coiling, flow diverter stenting, or surgical clipping.Methods: Consecutive patients with RIAs treated between April 2015 and June 2021 were retrospectively investigated. Clinical characteristics, treatment complications, and patient outcomes data were collected.Results: Among 108 RIAs treated in our hospital, 60 patients underwent initial coiling; 10 patients underwent staged treatment. The aneurysm locations were the anterior communicating artery (n = 5), internal carotid-posterior communicating artery (n = 3), internal carotid-paraclinoid (n = 1), and vertebral artery-posterior inferior cerebellar artery (n = 1). The mean ± standard deviation aneurysmal diameter was 9.6 ± 5.4 mm and the mean aspect ratio was 1.2 ± 0.7. As the second treatment to obliterate blood flow to the neck area, we performed five stent-assisted coiling, two flow-diverter stentings, and three surgical clippings. Only one minor perioperative complication occurred. The median duration between the first and second treatments was 18 days (range, 14– 42 days). Good clinical outcome (modified Rankin scale score 0–2) at 90 days was achieved in 5 (50%) cases. The median follow-up duration was 6.5 months (range, 3–35 months); no rerupture occurred.Conclusion: Intentional staged treatment with a short time interval for RIA was effective and feasible.

Validity of PETRA-MRA for Stent-Assisted Coil Embolization of Intracranial Aneurysms.

Pointwise encoding time reduction with radial acquisition (PETRA) using magnetic resonance angiography (MRA) is a non-enhanced MRA technique employing an ultrashort echo time, and is known to significantly reduce the magnetic susceptibility of coils and stents during post-embolization imaging. We evaluated the quality of PETRA-MRA images for use at the follow-up assessment of stent-assisted coil embolization procedures performed to treat aneurysms. A total of six aneurysm patients who were treated by stent-assisted coil embolization were included. All patients underwent PETRA-MRA, time-of-flight (TOF)-MRA performed with MAGNETOM Skyra (Siemens), and digital subtraction angiography (DSA) performed with Infinix Celeve-i INFX-8000V (Canon Medical Systems) and Allura Clarity FD20/15 (Philips). The PETRA-MRA images were compared with those from DSA and TOF-MRA to validate the aneurysm occlusion status and visually assess the blood flow within the stent. Four independent specialists graded occlusion status and flow visualization through the stent using a four-point scale, where 4 points represented excellent visualization of flow within the stent. The aneurysm was located in the internal carotid artery in two patients, the middle cerebral artery in two patients, the top of the basilar artery in one patient, and the vertebral artery-posterior inferior cerebellar artery (VA-PICA) in one patient. Three patients were treated using a Neuroform Atlas Stent system, one using an Enterprise2 VRD, one using two Neuroform Atlas stents for Y-stenting, and the remaining patient using a Neuroform Atlas and an Enterprise2 VRD for Y-stenting. With DSA, the postoperative aneurysm occlusion status was neck remnant (NR) in five cases and complete obliteration (CO) in one case. DSA and PETRA-MRA evaluations demonstrated an equal occlusion status in five of six cases, whereas DSA and TOF-MRA were equal in two of six cases. The mean visualization score for PETRA-MRA was 3.33 ± 0.82, whereas that for TOF-MRA was 2.17 ± 1.33. On the PETRA-MRA images, blood flow through the stent was well-visualized and produced an aneurysm occlusion status score comparable to DSA, especially in the three cases using the Neuroform Atlas Stent System where the visualization was scored 4 points. In the case of the VA-PICA aneurysm, for which an Enterprise2 VRD was used, PETRA-MRA images were insufficient for postoperative assessment. PETRA-MRA can provide good visualization of the blood flow within a stent and displays a clear blood signal near the coils, barring small magnetic susceptibility artifacts. Therefore, PETRA-MRA may be an effective option for follow-up imaging after stent-assisted coil embolization.

Institutional Experience of Microsurgical Management in Posterior Circulation Aneurysm.

Introduction:Posterior circulation aneurysm constitutes 15%–20% of all intracerebral aneurysms. With the advancement of endovascular techniques, the microsurgery for posterior circulation aneurysms has been pushed back a little. Even the International Subarachnoid Aneurysmal Trial gave support to the concepts of endovascular procedures, but microsurgical modality should not be discouraged. We present our institutional experience of microsurgical techniques on posterior circulation aneurysms.Materials and Methods:We performed a retrospective analysis of 37 patients of posterior circulation aneurysm from 2015 to 2019, referred to Bantane Hospital, Japan. We included all posterior circulation aneurysms such as basilar tip, basilar trunk, and vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms, admitted and treated with clipping or bypass and trapping. We assessed the outcome as measured by modified Rankin Score (mRS), complications, and mortality.Results:Out of 37 patients, 10 cases were a basilar tip, one case was the basilar trunk, and 26 cases were VA-PICA aneurysm. Intraoperatively, neuromonitoring, indocyanine green dye, dual-image videoangiography (DIVA), and neuro endoscope were used. Two patients of basilar tip aneurysm developed third cranial nerve paresis and six patients of VA-PICA aneurysm developed lower cranial nerve paresis which resolved spontaneously. All the patients were discharged with mRS of 0 or 1. No mortality was recorded in our study.Conclusion:Microsurgical clipping of posterior circulation aneurysm is safe in unruptured aneurysm with a very low risk of mortality and morbidity under experienced hands. All postoperative complications in our study were transient and resolved with time with no residual deficits. Preoperative simulation, intraoperative neuromonitoring, DIVA, and neuro endoscope help achieve complete obliteration of aneurysmal sac and avoid complications.

Endovascular sacrifice of the proximal posterior inferior cerebellar artery for treatment of ruptured intracranial aneurysms

BackgroundRuptured aneurysms of the intracranial vertebral artery (VA) or posterior inferior cerebellar artery (PICA) are challenging to treat as they are often dissecting aneurysms necessitating direct sacrifice of the diseased...

Association between Vertebral Artery Hypoplasia and Vertebral Artery Aneurysms: A Case-Control Study.

The aim of this retrospective case-control study was to determine the association of vertebral artery hypoplasia (VAH) and other anatomical variants with saccular vertebral artery posterior inferior cerebellar artery (VA-PICA) aneurysms. The frequency of VAH, vertebral artery (VA) atresia, VA aplasia, and PICA aplasia was analyzed using computed tomography (CT) angiography in 64 patients with VA-PICA aneurysms (43 ruptured and 21 unruptured) and compared with 128 age- and sex-matched controls. Logistic regression was performed to identify independent risk factors for aneurysm formation. Univariate analysis showed that patients with VA-PICA aneurysms had a significantly higher frequency of VAH (53% versus 17%; odds ratio [OR] 4.8; 95% confidence interval [CI], 2.4-9.4; p < 0.0001) and VA aplasia (14% versus 1%; OR 20.8; 95% CI, 2.5-168.0; p = 0.004) compared with controls. VA-PICA aneurysms are detected significantly more often in the dominant VA, which is contralateral to VAH. Other anatomical variants are not related to aneurysm formation. VAH and VA aplasia are potential risk factors for VA-PICA aneurysms. Altered hemodynamics caused by VAH may result in intracranial aneurysm formation. Additional research should clarify the pathophysiologic association of VAH, VA aplasia, or vascular occlusion with arteriosclerosis and intracranial aneurysm formation.

Association between vertebral artery hypoplasia and vertebral artery aneurysms: A case-control study

BackgroundThe aim of this retrospective case-control study is to determine the association of vertebral artery hypoplasia (VAH) and other anatomical variants with saccular vertebral artery posterior inferior cerebellar artery (VA-PICA) aneurysms. MethodsThe prevalence of VAH, vertebral artery (VA) atresia, VA aplasia, and PICA aplasia was analyzed using CT angiography in 64 patients with VA-PICA aneurysms (43 ruptured and 21 unruptured) and compared to 128 age- and sex-matched controls. Logistic regression was performed to identify independent risk factors for aneurysm formation. ResultsUnivariate analysis showed patients with VA-PICA aneurysms had significantly higher incidence of VAH (53% vs. 17%; odds ratio [OR] 4.8; 95% confidence interval [CI] 2.4–9.4; p < 0.0001) and VA aplasia (14% vs. 1%; OR 20.8; 95% CI 2.5–168.0; p = 0.004) compared with controls. Multivariate analysis identified VAH (odds ratio, 3.6; 95% CI 1.8–7.3; p < 0.0001) as an independent strong risk factor for VA-PICA aneurysm formation. VA-PICA aneurysms are detected significantly more often in the dominant VA, which is contralateral to VAH. Other anatomical variants are not related to aneurysm formation. ConclusionsVAH and VA aplasia are potential risk factors for VA-PICA aneurysms. Altered hemodynamics caused VAH may result in intracranial aneurysm formation. Additional research should clarify the pathophysiological association of VAH, VA aplasia, or vascular occlusion with arteriosclerosis and intracranial aneurysm formation.

Utility of Single Fenestrated Miniclip in Management of Small Cerebral Aneurysm: Technical Report of 2 Cases

Fenestrated miniclips were developed as an effective tool for dog-ear-shaped remnants of aneurysms. However, the special property of these clips may have other applications. Here, we report 2 cases of ruptured small aneurysm and suggest the alternative utility of a single application of a fenestrated miniclip. A 77-year-old woman was admitted to our hospital with subarachnoid hemorrhage due to an anterior communicating aneurysm. The aneurysm was treated with surgical clipping via a right pterional approach. Because dissection of tight adhesion between the aneurysm and ipsilateral A2 might cause intraoperative bleeding, the angled fenestrated miniclip was applied across the ipsilateral A2 without dissection of adhesion and obliterated the aneurysm without complications. In another case, a 60-year-old man presented with subarachnoid hemorrhage due to ruptured vertebral artery-posterior inferior cerebellar artery (PICA) aneurysm and was treated with surgical clipping via a far-lateral approach. Because aneurysm visualization was impeded by PICA even after mobilization of the PICA and vertebral artery, a fenestrated standard-clip was applied across the PICA. However, this clip impeded visualization of the aneurysm and could not be opened in the tight surgical field. In contrast, subsequent application of a fenestrated miniclip allowed better visualization of the aneurysm, even in a tight field, and resulted in successful obliteration of the aneurysm. Single application of fenestrated mini-clips may be suitable in cases of small aneurysms with thin walls adhering to branch vessels or where visualization of the aneurysm is impeded by the parent artery.

Comparison of Clinical and Radiologic Outcomes of Diverse Endovascular Treatments in Vertebral Artery Dissecting Aneurysm Involving the Origin of PICA

To determine clinical and radiologic outcomes of vertebral artery dissecting aneurysms involving posterior inferior cerebellar artery according to different types of endovascular treatment. This study included 18 vertebral artery dissecting aneurysms (6 ruptured and 12 unruptured) involving posterior inferior cerebellar artery treated from January 2009 to December 2016. Treatments were multiple stenting, stent-assisted coil embolization, vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting, and Pipeline embolization. Clinical and radiologic information were obtained from retrospective chart review and radiologic review. Subarachnoid hemorrhage was diagnosed initially in 6 of 18 patients, and infarction was diagnosed initially in 2 patients. Multiple stenting was performed in 4 patients, including 1 (25%) who had cerebellar infarction and 1 (25%) who had recurrence. Stent-assisted coil embolization was performed in 8 patients, including 1 (12.5%) who had postoperative cerebellar infarction and 2 (25%) who had recurrence. Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting was performed in 4 patients, including 1 (25%) who had postoperative cerebellar infarction. There was no recurrence (0%). Pipeline embolization was performed in 2 patients, including 1 (50%) who had recurrence. There was no postoperative infarction (0%). No subarachnoid hemorrhage occurred during follow-up. Deterioration in modified Rankin Scale score was found only in the stent-assisted coil embolization group (1/8; 12.5%). Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting showed the lowest rate of aneurysm recurrence with high rate of minor infarction and favorable neurologic outcome. Stent-assisted coil embolization showed high recurrence rates with possible fatal disabling infarction.

A True Posterior Inferior Cerebellar Artery Aneurysm Forming Kissing Aneurysms with a Ruptured Vertebral Artery-Posterior Inferior Cerebellar Artery Aneurysm: A Case Report

We report a case of an unruptured true posterior inferior cerebellar artery (PICA) aneurysm forming kissing aneurysms with a ruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm in a 49-year-old woman that was successfully treated with direct surgery. Left vertebral angiogram revealed a VA-PICA aneurysm and an adjacent small bulge in the PICA. Intraoperatively, these two aneurysms adhered tightly to one another, necessitating complete dissection and clipping of both aneurysms. This is the first case of kissing aneurysms at the VA-PICA junction to be reported. It is important to remember that we may encounter kissing aneurysms of VA-PICA and PICA. As in the present case, preoperative diagnosis may be difficult.

Far-Lateral Approach Without Drilling the Occipital Condyle for Vertebral Artery-Posterior Inferior Cerebellar Artery Aneurysms.

The far-lateral transcondylar surgical approach is often used to clip vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms. The role of condyle resection during this approach is controversial. To evaluate patient outcomes in patients with VA-PICA aneurysms in whom drilling the occipital condyle was not necessary. Between May 2005 and December 2012, a total of 56 consecutive patients with incidental or ruptured VA-PICA aneurysms underwent surgery with a far-lateral approach without condylar resection. Clinical presentation, surgical reports, presurgery and postsurgery radiological examinations, and clinical follow-up reports were assessed. Anatomic aneurysm location was analyzed through angiography or computed tomography angiography. We compared postsurgical Glasgow Outcome Scale scores, modified Rankin Scale scores, and morbidity in 2 groups: those with aneurysms in the anterior medullary segment and those with aneurysms in the lateral medullary segment. The predominant presentation was subarachnoid hemorrhage in 34 patients (60.7%). Most aneurysms (n = 27 [48.2%]) were located in the lateral medullary segment of the PICA, followed by the anterior medullary segment (n = 25 [44.6%]). Total aneurysm occlusion was achieved in 100% of patients, and bypass techniques were necessary in 3 patients (5.4%). Fifty-two patients (92.8%) had Glasgow Outcome Scale scores of 4 or 5 postsurgery. A far-lateral approach that leaves the occipital condyle intact is adequate for treating most patients with VA-PICA aneurysms.

Surgical treatment of unruptured dissecting intracranial aneurysms of vertebral-posterior inferior cerebellar artery region.

A lack of published surgical experience and higher symptomatic recurrence than previously recognized prompted the authors to present their experience with the surgical treatment of unruptured intracranial dissecting aneurysms (UIDAs). Hospital records, neuroimaging studies, operative reports, and follow-up records were retrospectively reviewed. All patients underwent surgical exploration of the lesion with proximal clipping of the parent artery through a far-lateral suboccipital craniotomy with or without partial condylar resection. The surgical treatment of vertebral artery-posterior inferior cerebellar artery UIDAs has acceptable risk regarding perioperative mortality and morbidity. The incidence of aneurysmal recurrence or the need for retreatment seems to be less than that associated with anticoagulation/antiplatelet therapy or endovascular treatment.

Vertebral artery-posterior inferior cerebellar artery convergence aneurysms treated by endovascular or surgical treatment: Mid- and long-term outcome

IntroductionManagement of vertebral artery-posterior inferior cerebellar artery convergence (VA-PICA) saccular aneurysms requires a specialized neurovascular team. The objective is to preserve the functional outcome while performing a complete and reliable long-term exclusion of the aneurysm. ObjectiveThe aim of our study was to evaluate the outcome of patients with VA-PICA saccular aneurysms after treatment. Materials and methodsThis was a retrospective series of 21 consecutive patients with a VA-PICA saccular aneurysm treated between 2000 and 2012 at our institution. Treatment option (endovascular or microsurgical) was decided for each patient following a multidisciplinary discussion. ResultsTwenty-one patients were treated for a VA-PICA saccular aneurysm including 16 for a ruptured aneurysm and 5 for an asymptomatic aneurysm. Among all patients, 11 underwent endovascular treatment and 10 had microsurgical treatment. Our results showed a major aneurysm recurrence after endovascular treatment in 3 patients that required a further endovascular treatment in 2 cases. These 3 major recurrences occurred after treatment of a ruptured aneurysm when the initial angiography demonstrated the origin of the PICA at the neck of the aneurysm. After microsurgery, angiography showed a remnant neck in 2 patients including 1 treated by further endovascular procedure. ConclusionVA-PICA aneurysms are rare and require multidisciplinary management. Microsurgical treatment should be discussed when the PICA originates from the aneurysmal neck, particularly in patients with a ruptured small aneurysm, in order to obtain a reliable and long-term exclusion of the aneurysm.

Fluid structure interaction analysis reveals facial nerve palsy caused by vertebral-posterior inferior cerebellar artery aneurysm

Cranial nerve palsy caused by aneurysmal compression has not been fully evaluated. The main causes of symptoms are considered to be direct mechanical compression and aneurysm pulsations. Recent studies indicate that nerve dysfunction is mainly induced by pulsation rather than by direct compression, and successful cases of endovascular surgery have been reported. We describe a patient with an unruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm compressing the facial nerve at the root exit zone (REZ). The patient presented with peripheral facial nerve palsy but not hemifacial spasm and was successfully treated by coil embolization. To investigate the mechanisms underlying peripheral facial nerve palsy, fluid structure interaction (FSI) analysis can approximate displacement and the magnitude of aneurysmal wall motion due to hemodynamic forces. In our case, maximum mesh displacement was observed at the aneurysmal wall attached to the facial nerve inside the pons rather than the REZ, which explains the clinical manifestation of facial nerve palsy in the absence of hemifacial spasm. This preliminary report demonstrates the utility of FSI analysis for investigating cranial nerve neuropathy.

Assessment of endovascular coil configuration for embolization of intracranial aneurysms using computational fluid dynamics.

Endovascular coil embolization of arterial aneurysms is often complicated by reduced blood flow to branching arteries. To determine the optimal coil configuration for safe embolization of endovascular aneurysms without compromising blood flow in branching arteries. A 3-dimensional voxel model, built based on an unruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm, predicted to show impairment of flow in the PICA during endovascular coil embolization (Case 0). Six different models of final coil configuration were generated and applied to this aneurysm. Case 1 was a round coil mass. Case 2 was designed with a stent assist. Cases 3, and 4 were designed with a neck remnant and Cases 5 and 6 incorporated a balloon neck remodeling technique. Computational fluid dynamics was used to analyze the flow in the PICA in each model. The average outflow to the PICA was highest in Case 0 and lowest in Case 2 (in descending order, Case 0, 5, 4, 6, 1, 3, and 2). There was better preservation of outflow to the PICA in the balloon neck remodeling models than in the neck remnant models. In a model of endovascular coil embolization, we found considerable differences in outflow to the branching artery with small changes in coil configuration. Careful preoperative planning is important to minimize the risk of thromboembolic events during and after endovascular coil embolization.

Anatomical features of the vertebral artery for transbrachial direct cannulation of a guiding catheter to perform coil embolization of cerebral aneurysms in the posterior cerebral circulation.

Transbrachial approach is an alternative technique for coil embolization of posterior circulation aneurysms. The purpose of our study was to investigate the anatomical features of the vertebral artery (VA) for transbrachial direct VA cannulation of a guiding catheter (GC) to perform coil embolization of posterior circulation aneurysms. Included in retrospective analysis were patients who underwent transbrachial coil embolization of cerebral aneurysms in the posterior cerebral circulation by direct VA cannulation of a GC from 2007 to 2013. Investigated were patient characteristics, preoperative sizes of aneurysms, aneurysms location, the angle formed by the target VA and the subclavian artery (AVS), and the VA diameter at the level of the fourth cervical vertebral body (VAD) in the side of the transbrachial access route. Thirty-one patients with 32 aneurysms met our criteria. The locations of aneurysms were the VA (n = 16), basilar artery (BA) tip (n = 10), BA trunk (n = 3), BA superior cerebellar artery (n = 1), BA anterior inferior cerebellar artery (n = 1), and VA posterior inferior cerebellar artery (n = 1). The right brachial artery was punctured in 27 cases with 28 aneurysms as transbrachial direct cannulation of a GC, and left was in 4 cases with 4 aneurysms. The average AVS, ranging from 45° to 95°, was 77°, and the average VAD, ranging from 3.18 to 4.45 mm, was 3.97 mm. For transbrachial direct cannulation of a GC, it seems required that the AVS is about 45° or more and the VAD is about 3.18 mm or more.

Long-term outcomes of trapping vertebral artery-posterior inferior cerebellar artery dissecting aneurysms after revascularization

This study is designed to evaluate the long-term outcome of trapping vertebral artery-posterior inferior cerebellar artery (VA-PICA) dissecting aneurysms after revascularization. Five patients with VA-PICA dissecting aneurysms were treated surgically between 2007 and 2010. All the aneurysms were trapped through a far-lateral approach after revascularization of the PICAs by occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass. All patients were scheduled for clinical follow-up in the out-patient department at 3 months, 6 months, then annually. Computed tomography (CT) scan and CT angiography, or magnetic resonance (MR) imaging and MR angiography were performed to assess the anastomosis and cerebral blood supply. Among the five patients, two of them did not have any neurological deficit after surgery, the other three had post-operative lower cranial nerve palsy but recovered completely within 6 months. Post-operative cerebral angiography (received by two patients) and CT angiography (received by the other three patients) showed patent bypasses in all patients and there was no reappearance of the aneurysms. After following-up from 47 to 74 months (61 month is the median follow-up period), all patients showed excellent outcomes. Trapping the aneurysms after revascularization of PICAs by OA-PICA bypass is a safe method to treat the VA-PICA dissecting aneurysms.

椎骨動脈─後下小脳動脈分岐部囊状動脈瘤に対するコイル塞栓術の治療成積

There are technical difficulties that may be encountered during endovascular coiling for saccular vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms because some have unfavorable morphology such as a side branch arising from the aneurysm neck and a shallow aneurysm dome. We analyzed the clinical and radiological outcomes of endovascular coiling for saccular VA-PICA aneurysms. We also investigated morphological factors associated with coiling success and failure to evaluate the safety and feasibility of this treatment. Between March 1997 and September 2012, we treated 24 cases (19 ruptured and five unruptured aneurysm cases) of saccular VA-PICA aneurysms with endovascular coiling. All 24 aneurysms demonstrated a side-branch arising from the neck on digital subtraction angiography. Twenty cases with VA-PICA aneurysms were successfully embolized with coiling while there were four failures. One ruptured case experienced symptomatic ischemic complication that resulted from delayed distal coil migration. An aspect ratio of ＜1.2 and an aneurysm-parent artery angle of ＜90° were associated with failure of endovascular coiling. Of the 20 coil-treated aneurysms, immediate angiographic results showed near-complete aneurysm occlusion in 12/20 (60.0%) cases, neck remnant in five (25.0%), and residual aneurysm in three (15.0%). One patient (5%) had a major aneurysm recurrence that was uneventfully reembolized. Thirteen of 19 ruptured cases (68.4%) cases had good outcomes (modified Rankin Scale 0–2), two (10.5%) had moderate disability (mRS 3), and one (5.3%) had severe disability (mRS 4–5) at three months after treatment. The results of this study suggest that endovascular coiling is safe and feasible for saccular VA-PICA aneurysms. However, surgical clipping can be expected to benefit younger patients and/or cases of unfavorable morphology such as low aspect ratio. In addition, adverse angulation between aneurysm and parent artery can be another morphological factor for which an endovascular procedure is technically demanding.

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.

Endovascular Treatment of Ruptured and Unruptured Vertebral Artery Aneurysms

This paper analyzes the success of endovascular management of ruptured and unruptured vertebral artery aneurysms. Sixty-three patients with 65 vertebral (both acute dissection and chronic larger aneurysms are included) treated at our hospital form the basis of the analysis. Clinical outcome was evaluated using the modified Rankin Scale. Angiographic follow-up data was obtained for 44 patients (69.8%) for periods ranging from three to 16 months (mean, eight months). Based on the Hunt and Hess grading scale, the patient population included 34 patients (54.0%) with unruptured aneurysms, 28 (44.4%) with Grade 1 aneurysms, one (1.6%) with Grade 2 aneurysms. The locations of the aneurysms included 25 (38.5%) at the distal to posterior inferior cerebellar artery (PICA), 22 (33.8%) at the proximal to PICA and 18 (27.7%) at the vertebral artery-posterior inferior cerebellar artery (VA-PICA). Of the 63 patients, 12 (19%) were women and 51 (81%) were men. The mean age at treatment was 41.7 years (range, six-77 yrs). Follow-up angiograms were obtained in 44 (69.8%) out of 63 patients. Complete or virtually complete thrombosis was confirmed on early posttreatment angiography in 39 (88.6%) out of 44 patients. A slight reduction in the size of the lesion was noted in three patients and there was a significant residual lesion in two (4.5%) patients. Clinical follow-up revealed 90.5% patients in the mRS 0-2 category, 4.8% patients in the mRS>2 category, and 4.8% patients had died (mRS 6). Three patients died of rebleeding (n=1) or progressive mass effect/brainstem ischemia (n=2). Ruptured and unruptured aneurysms of the vertebral artery can be well treated using endovascular techniques, overall long-term results were good in 90.5% of patients.