A "PICA communicating artery" aneurysm: case report.

We present an unusual case of an aneurysm of the distal posterior inferior cerebellar artery (PICA). The aneurysm was associated with a unilateral PICA that supplied both cerebellar hemispheres and arose from an anastomotic vessel to the contralateral circulation, a branch of the contralateral PICA. Such an aneurysm has not been reported previously. The associated of vascular anomalies with aneurysms of the PICA is discussed.     

Development of unusual collateral channel from the posterior meningeal artery after endovascular proximal occlusion of the posterior inferior cerebellar artery

A 38-year-old man presented with a dissecting aneurysm of the left proximal posterior inferior cerebellar artery (PICA) manifesting as Wallenberg's syndrome. The patient was treated by endovascular occlusion of the aneurysm and parent artery. Immediately after the treatment, the PICA territory was supplied by collateral circulation via the ipsilateral anterior inferior cerebellar artery. Seven days later, endogenous revascularization of the distal PICA territory had occurred via collateral circulation from the posterior meningeal artery (PMA). This unusual collateral circulation was thought to occur through a pre-existing anastomotic channel between the primitive vessels of the PICA and the PMA during subclinical hypoperfusion of the distal PICA territory. This unusual case demonstrates the potential for delayed development of collateral circulation from the PMA to the PICA territory.     

Multiple aneurysms of the PICA communicating artery: a case report

A case with unusual type of aneurysms in the distal posterior inferior cerebellar artery (PICA) is reported here. Though only two cases with a single aneurysm of the PICA communicating artery have been reported previously, the present case is the first one with multiple aneurysms in the PICA communicating artery. A 61-year-old woman with a sudden onset of severe headache, vomiting and unconsciousness was transferred to our hospital. CT scan revealed a hematoma in the fourth, third, and lateral ventricles, and a mild subarachnoid hemorrhage at the posterior fossa. Cerebral angiogram showed the right PICA supplying the hypoplastic left PICA territory through an anastomotic vessel. Two small aneurysms were seen at the tips of hairpin curves of an anastomotic vessel, "the PICA communicating artery". Suboccipital craniotomy was performed, and the ruptured aneurysm was clipped and the unruptured one was wrapped with cotton-sheet. After the operation, her clinical recovery went well and she was discharged on foot.     

Bilateral anomalous posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomotic arteries associated with a ruptured cerebral aneurysm--case report

A 50-year-old man presented with subarachnoid hemorrhage from a ruptured cerebral aneurysm arising from a left posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery anastomotic artery manifesting as severe headache, obtundation, and quadriplegia. Conventional and three-dimensional digital subtraction angiography showed that the anastomotic complex was present bilaterally and both vertebral arteries terminated at the origin of the PICA. The identification of this anomalous vascular network allowed coil embolization of the broad-based aneurysm with occlusion of the parent artery. The patient had residual moderate disturbance of consciousness and quadriplegia before transfer for rehabilitation.     

Posterior inferior to posterior inferior cerebellar artery anastomosis combined with trapping for vertebral artery aneurysm. Case report

A case is presented in which a giant intracranial vertebral artery aneurysm gave rise to an associated ipsilateral posterior inferior cerebellar artery (PICA) from its waist. Proximal vertebral artery ligation at C-1 was achieved. The aneurysm filled from the opposite vertebrobasilar junction. Direct intracranial trapping of the right vertebral aneurysm was followed by successful anastomosis of the proximally sectioned right PICA to the adjacent left PICA in an end-to-end fashion.     

Aneurysm of the distal posterior inferior cerebellar artery originating from the extracranial and extradural vertebral artery

A 42-year-old woman presented with a ruptured aneurysm of the distal posterior inferior cerebellar artery (PICA), which had a rare extracranial and extradural origin. Medial suboccipital craniectomy and C-1 laminectomy were performed. The aneurysm had adhered to the right cerebellar tonsil, but was successfully clipped without difficulty. Intraoperatively, the PICA origin was recognized in the extracranial and extradural space between the dorsal roots of the C-1 and C-2 nerves. The origin of the PICA from the vertebral artery (VA) may occur at any portion of the VA from the site of penetration of the dura to the vertebrobasilar junction, but an extradural origin is uncommon. A ruptured aneurysm of the PICA branching from the VA at a site proximal to the vertebrobasilar junction and below the foramen magnum may be overlooked by three-vessel angiography if the contrast medium cannot reflux to the contralateral PICA origin.     

Peripheral aneurysms of the posterior inferior cerebellar artery

Nonmycotic peripheral posterior inferior cerebellar artery (PICA) aneurysms are rare. The authors report six cases of peripheral PICA aneurysm. Two of these are unusual; one was fusiform and another was a double aneurysm arising from the peripheral PICA. The previously reported 40 cases of peripheral PICA aneurysm are reviewed.     

Vertebral artery occlusion with vertebral artery-to-posterior inferior cerebellar artery stenting for preservation of the PICA in treating ruptured vertebral artery dissection

We report a patient with a right vertebral artery (VA) dissecting aneurysm who was treated by placing an Enterprise stent (Cordis Neurovascular, Miami Lakes, FL) from the proximal VA to the posterior inferior cerebellar artery (PICA) in order to save the patency of the PICA. A 47-year-old man was admitted with a ruptured right VA dissecting aneurysm that involved the origin of the PICA. A 4.5 × 37-mm Enterprise stent was then placed through the proximal VA to the PICA. The dissected segment of the VA was completely occluded by coil embolization. The 1-year follow-up angiography showed that the dissected segment was completely occluded and the diameter of the PICA was slightly increased, and the PICA’s patency was good.     

A growing aneurysm of the posterior inferior cerebellar artery complicated with cerebellar infarction: A case report

Introduction and importanceHereby we describe an instructive patient with cerebellar infarction and a growing aneurysm at the posterior inferior cerebellar artery (PICA), which was not a true cause of infarction.Case presentationA 50-year-old female presented with dizziness and posterior neck pain at our hospital (Mitaka city, Tokyo, Japan). Diffusion weighted magnetic resonance (MR) images showed cerebellar infarction in the left PICA territory and MR angiography study showed an aneurysm at the origin of the left PICA, which grew in 2 weeks. Since we considered cerebellar infarction was caused by thrombosis from the aneurysm, trapping of the PICA and occipital artery-PICA bypass was performed to prevent recurrent cerebellar infarction and rupture of the aneurysm by neurosurgeons. During the operation, dissection was observed at the distal PICA, which was diagnosed to be the true cause of cerebellar infarction. By the follow-up for 12 months at an outpatient, there was no recurrence of cerebral infarction.Clinical discussionA specimen of the artery showing the findings of dissection was not obtained, and the pathological diagnosis could not be made. It would be controversial whether a surgical procedure presented here was the most optimal.ConclusionThis is a first reported case of growing aneurysms and cerebral infarction due to arterial dissection. Even if cerebral infarction is accompanied by growing aneurysms, arterial dissection should be included in the differential diagnoses of a cause of infarction. Posterior cervical pain can be a clue for early appropriate diagnosis in such a case.     

Ruptured aneurysm of a posterior inferior cerebellar artery communicating artery. Case report and histological findings

A hypertensive 60-year-old man presented with a rare aneurysm arising from the posterior inferior cerebellar artery (PICA) communicating artery, manifesting as subarachnoid hemorrhage with intraventricular hemorrhage. Angiography showed a small aneurysm arising from a fine and tortuous artery interconnecting the bilateral vermian branches of distal PICAs. The right PICA was absent and its vermian territory was supplied by the left PICA through this communicating artery. The right anterior inferior cerebellar artery was also connected to the vermian branch of the right PICA. At surgery, a reddish and apparent fusiform aneurysm was noted at the top of the arterial loop under the cerebellar vermis. Microsurgical trapping and removal of the aneurysm was performed without complication. Histological examination demonstrated typical findings of a true aneurysm. Only four previous cases of aneurysm of the communicating artery between the bilateral distal PICAs have been reported. In all five reported cases including ours, the PICA communicating artery contributed to the collateral blood supply of the contralateral vermian territory based on vascular anomalies. Hemodynamic stress and congenital vulnerability may have caused this aneurysm. Trapping is suitable to treat this precarious aneurysm if other collateral vessels supply the contralateral vermian territory.     

Clip reconstruction for a case of peripheral posterior inferior cerebellar artery aneurysm: case report.

The authors report an unusual surgical treatment for an aneurysm on the left peripheral posterior inferior cerebellar artery (PICA). The computed tomographic scan showed subarachnoid haemorrhage and a haematoma in the left cerebellar region close to the fourth ventricle. The 3D CT angiography demonstrated an aneurysm on the left peripheral PICA which was confirmed on four-vessel angiography. The aneurysm was approached through a posterior suboccipital craniotomy and the PICA was reconstructed with multiple clips. The literature concerning peripheral PICA aneurysms and their treatment is reviewed and discussed.     

Treatment of unruptured saccular vertebral artery aneurysm for preservation of the parent artery for advanced age people: a case report

A 79-year-old female was referred to our hospital presenting with occipital headache. Her unruptured aneurysm was incidentally found by magnetic resonance angiography. Three dimensional computed tomographic angiography showed a saccular aneurysm located at the junction of the left vertebral artery (VA) and posterior inferior cerebellar artery (PICA) that originated from the aneurysm itself. Firstly, surgical clipping of the left PICA just distal to the aneurysm and occipital artery (OA)-PICA bypass was carried out and, secondly, endovascular treatment was performed for preservation of the parent artery.     

Dissecting Aneurysm of the Peripheral Posterior Inferior Cerebellar Artery

Dissecting aneurysms of intracranial posterior circulation have recently been shown to be less uncommon than previously thought. However, those involving the posterior inferior cerebellar artery (PICA) and not vertebral artery at all are extremely rare. We report here a case of a patient with a dissecting aneurysm of the lateral medullary segment of PICA which presented as subarachnoid haemorrhage. The aneurysm was treated by trapping surgery and the distant PICA was anastomosed to the occipital artery. The patient showed a slight ataxia immediately after surgery but recovered fully. Recovery from immediately postoperative cerebellar symptoms due to intra-operative ischemia seemed to be due largely to recovery of flow in the region of cortical branches of PICA.     

Treatment of vertebral artery aneurysms with transposition of the posterior inferior cerebellar artery to the vertebral artery combined with parent artery occlusion. Technical note

The authors describe transposition of the posterior inferior cerebellar artery (PICA) to the vertebral artery (VA) combined with parent artery occlusion for the treatment of VA aneurysms in cases in which a clip could not be applied because of the origin of the ipsilateral PICA. The aneurysm is trapped through a lower lateral suboccipital craniectomy. The PICA is then cut just distal to the aneurysm, and the PICA and VA proximal to the aneurysm are anastomosed in an end-to-end or end-to-side fashion. The surgical procedure was successfully performed in two patients, each of whom had hypoplastic occipital arteries (OAs). The PICA contralateral to the lesion was hypoplastic in one patient and distant to the ipsilateral PICA in the other patient. Mild transient dysphagia developed postoperatively in one patient due to glossopharyngeal and vagus nerve palsy, and the other patient had an uneventful postoperative course. In both patients, postoperative cerebral angiography demonstrated good patency of the transposed PICA. These results show that transposition of the PICA to the VA is a useful procedure for the reconstruction of the PICA when parent artery occlusion is necessary to exclude a VA aneurysm involving the origin of the PICA and when OA-PICA anastomosis or PICA-PICA anastomosis cannot be performed.     

Subarachnoid hemorrhage caused by posterior inferior cerebellar artery aneurysm with an anomalous course of the atlantoaxial segment of the vertebral artery. Case report and review of literature

Various anatomical courses of the vertebral artery (VA) and posterior inferior cerebellar artery (PICA) have been described. The authors present a unique case of a subarachnoid hemorrhage resulting from an aneurysm in a patient with an anatomical variation of the extracranial portion of the VA and cervical origin of the PICA. The surgical implications of this variant are discussed, and the pertinent literature reviewed. Subarachnoid hemorrhage caused by rupture of a PICA aneurysm is reported for the first time in association with a rare variation of the course of the VA.     

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion

BACKGROUND: In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion. METHODS: After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm. RESULTS: Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits. CONCLUSION: PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.     

Giant peripheral aneurysm of the posterior inferior cerebellar artery treated with excision and end-to-end anastomosis

A patient with a giant aneurysm arising from the tonsillomedullary segment of the posterior inferior cerebellar artery (PICA) presented with clinical and computed tomography findings suggestive of spontaneous cerebellar hemorrhage. Magnetic resonance imaging led to arteriography and the correct diagnosis. Lack of a clippable neck on the aneurysm and its location proximal to the choroidal point prompted treatment by excision of the aneurysm and end-to-end anastomosis of the PICA. No neurological deficit resulted from the procedure.     

Successful clipping of a distal posterior inferior cerebellar artery aneurysm located on the anterior surface of the medulla oblongata--case report

A 55-year-old male presented with a ruptured distal posterior inferior cerebellar artery (PICA) aneurysm manifesting as subarachnoid hemorrhage. Angiography demonstrated a saccular aneurysm arising from the lateral medullary segment of the left PICA and located on the medial side of the left vertebral artery (VA) and the anterior surface of the medulla oblongata. A transcondylar fossa approach was used to ensure a sufficient operating field and to obtain adequate visualization of the aneurysm, the parent artery, and the perforating arteries to the medulla oblongata. The aneurysm dome protruded medially at the hairpin curve, and was located on the medial side of the left VA and on the anterior surface of the medulla oblongata. There was no vessel branches in the vicinity of the aneurysm. The aneurysm was successfully clipped with minimum retraction of the cerebellar hemisphere and medulla oblongata. Distal PICA aneurysms can be located at various sites in the posterior fossa. The exact location of the aneurysm must be established to select the best surgical approach.     

Persistent primitive hypoglossal artery associated with proximal posterior inferior cerebellar artery aneurysm

BACKGROUND: A persistent primitive hypoglossal artery (PPHA) is a rare anomaly. The association of PPHA with intracranial aneurysms of the artery has also been rarely reported. We surgically treated a case of PPHA associated with a ruptured saccular aneurysm at the proximal posterior inferior cerebellar artery (PICA). CASE DESCRIPTION: The patient was admitted because of subarachnoid hemorrhaging. Angiography and three-dimensional computed tomography (CT) angiography (3D-CTA) demonstrated a left PPHA entering the posterior fossa through the left large hypoglossal canal. The left vertebral artery was absent. A saccular aneurysm was found at the junction of the PPHA and the proximal PICA. 3D-CTA showed not only the aneurysm itself but also the anatomical relationship between the aneurysm and the surrounding structures. Therefore, 3D-CTA was very useful in planning the surgery. The neck of the aneurysm was clipped through a far lateral approach associated with a C1 laminectomy, because this case had a large posterior condylar emissary vein and the aneurysm was located just posteroinferior to the hypoglossal canal. CONCLUSIONS: A case of PPHA associated with an aneurysm at the proximal PICA is reported. This case not only had a large hypoglossal canal but also had a huge posterior condylar emissary vein in the large posterior condylar canal. Anomalous structures associated with PPHA are also discussed. Finally, 3D-CTA proved to be very useful in planning the optimal surgical modality around the lateral portion of the foramen magnum.