Ruptured traumatic posterior inferior cerebellar artery pseudoaneurysm: A case report and literature review
- Department of Neurosurgery, Graduate School of Medicine, Kobe University, Chuo-ku, Kobe, Japan.
- Department of Neurosurgery, Toyooka Hospital, Toyooka, Hyogo, Japan.
Yusuke Ikeuchi, Department of Neurosurgery, Graduate School of Medicine, Kobe University, Chuo-ku, Kobe, Japan.
DOI:10.25259/SNI_410_2022Copyright: © 2022 Surgical Neurology International This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, transform, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
How to cite this article: Yusuke Ikeuchi1, Tomoya Shimasaki2, Naoki Nitta2, Yusuke Yamamoto2, Taiji Ishii2. Ruptured traumatic posterior inferior cerebellar artery pseudoaneurysm: A case report and literature review. 17-Jun-2022;13:257
How to cite this URL: Yusuke Ikeuchi1, Tomoya Shimasaki2, Naoki Nitta2, Yusuke Yamamoto2, Taiji Ishii2. Ruptured traumatic posterior inferior cerebellar artery pseudoaneurysm: A case report and literature review. 17-Jun-2022;13:257. Available from: https://surgicalneurologyint.com/surgicalint-articles/11656/
Background: Traumatic intracranial aneurysm (TICA) accounts for approximately 1% of cerebral aneurysms. There are few reports of TICA limited to the posterior inferior cerebellar artery (PICA-TICA).
Case Description: A 69-year-old woman fell into a shallow river, bruising her head and chest, and was admitted to our emergency department with disorientation. Computed tomography (CT) showed subarachnoid hemorrhage (SAH), intraventricular hemorrhage (IVH), left temporal lobe contusion, and fractures of the right temporal bone. A cerebral CT angiogram revealed no vascular abnormalities or aneurysms. The patient was in a semi-comatose state 2 h later, and CT showed worsening SAH. A cerebral angiogram revealed an 11 mm aneurysm of the anterior medullary segment of the right PICA. We attempted intra-aneurysmal embolization intending to preserve the PICA, but the aneurysmal neck was thin, and the microcatheter could not be placed in a stable position. Therefore, n-butyl-2-cyanoacrylate (NBCA) was injected to embolize the aneurysm. When the microcatheter was removed, NBCA was scattered distally in the PICA, and the distal PICA was occluded. The aneurysm could be embolized, but there was an increase in hemorrhagic contusion in the left temporal lobe. Decompression craniectomy was performed, but she died due to hemorrhagic contusion and uncal herniation 6 days after surgery.
Conclusion: PICA-TICA is often accompanied by IVH and SAH, and there are some reports of cases with a vascular anomaly of the posterior circulation. Since TICA is at risk of rapid growth and rupture, an early and appropriate diagnosis is important.
Keywords: Aneurysms, Computed tomography, Microcatheter, Posterior inferior cerebellar artery, Posterior, Traumatic intracranial aneurysm
Traumatic intracranial aneurysms (TICAs) comprise <1% of all cerebral aneurysms[
This case report outlines the steps taken to treat the PICA-TICA, patient outcomes, and lessons learned for effective treatment of future PICA-TICA patients. We also reviewed previous reports on the characteristics and treatment of PICA-TICA.
History and examination
A 69-year-old woman fell 3 m into a shallow river, bruising her head and chest. She was admitted to our hospital as an emergency case with no relevant medical history. In the emergency department, her Glasgow Coma Scale score was determined to be 11. She had a headache, nausea, and amnesia at the time of injury, but no apparent paralysis. She had a bruise on the right side of her head and swelling on the precordium.
Computed tomography (CT) showed SAH in the posterior fossa and left Sylvian fissure, IVH with slight ventriculomegaly, and contusion of the left temporal lobe [
(a and b) Computed tomography (CT) scans showed subarachnoid hemorrhage in the posterior fossa and left Sylvian fissure, intraventricular hemorrhage with slight ventriculomegaly, and contusion of the left temporal lobe. (c) Three-dimensional CT image showed fractures of the right temporal bone and zygoma. (d and e) A cerebral CT angiogram revealed no vascular abnormalities or aneurysms. (d) Three-dimensional CT angiography, (e) sagittal view of CT angiography.
(a) One hour later cerebral computed tomography (CT) images showed increased subarachnoid hemorrhage, intraventricular hemorrhage, and ventricular enlargement. (b) A right vertebral artery (VA) angiography three-dimensional image revealed an 11 mm aneurysm in the right posterior inferior cerebellar artery (PICA) anterior medullary segment (AMS). (c) The enlarged view of B. Green line is 11 mm and the orange line is 9 mm. It was considered a pseudoaneurysm because of its small and unclear aneurysmal neck. (d) The Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA) was approached to the aneurysm from the right VA using the Tenrou 1014 (Kaneka Medics, Kanagawa, Japan). However, with this approach, it was difficult to guide the microcatheter because the direction of the microcatheter and the aneurysm neck was almost at 180° with each other. (e) A Marathon catheter was approached to the aneurysm from the left VA beyond the union using the Tenrou 1014. (f) Microcatheter angiography revealed an aneurysm and backflow to the VA and PICA. The diameter of the small space at the entrance of the aneurysm where the Marathon microcatheter could be placed was approximately 1.5 mm. G: n-butyl-2-cyanoacrylate (NBCA) (12.5%) was injected into the aneurysm while blocking the proximal part of the right VA with a SHOURYU HR balloon (7 mm × 7 mm) (Kaneka Medics, Kanagawa, Japan) and suppressing the backflow to the VA. (h) Using NBCA, we were able to embolize a small part of the aneurysm neck. Although the Marathon microcatheter was carefully removed, its removal from the aneurysm caused NBCA to scatter into the PICA. (i) The right VA angiography revealed that the aneurysm had disappeared, but blood flow in the PICA was very slow.
Treatment and posttreatment course
Digital subtraction angiography (DSA) was performed to identify the source of the hemorrhage. Under local anesthesia, a 5-French introducer sheath was placed in the right femoral artery (FA). A six-vessel selective cerebral angiogram was performed using a 5-French JB2 125-cm catheter (Medikit, Tokyo, Japan). A right vertebral artery (VA) angiogram revealed an 11 mm aneurysm in the right PICA anterior medullary segment (AMS). It was considered a pseudoaneurysm because of its small and unclear aneurysmal neck [
Under local anesthesia, 3000 units of heparin were injected intravenously, and activated coagulation time (ACT) was extended to 250 s. A 5-French JB2 125 cm catheter was placed in the left VA for angiography to confirm blood flow. A 6-French introducer sheath was placed in the left FA, and a 6-French FUBUKI guiding catheter of 90 cm (Asahi Intecc, Aichi, Japan) was placed in the right VA. A Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA) was inserted into a 6-French FUBUKI with a Tenrou 1014 (Kaneka Medics, Kanagawa, Japan) to approach the aneurysm. However, with this approach, it was difficult to guide the microcatheter because the direction of the microcatheter and the aneurysm neck was almost at 180° with each other [
Immediately after the surgery, the level of consciousness was somnolent due to sedation, but no anisocoria was observed. Cerebral CT revealed dilated ventricles and contusive hemorrhage in the left temporal lobe with uncal herniation [
(a) Postoperative cerebral computed tomography (CT) image revealed a contusive hemorrhage in the left temporal lobe with uncal herniation. (b and c) External decompression and hematoma removal were performed, but a postoperative CT image showed an enlarged contusive hemorrhage and uncal herniation. (b) 3D image, (c) axial view.
In this case report, we described the diagnosis and treatment of PICA-TICA in a patient with TBI after a fall. Although we embolized the TICA, the patient did not survive. These results demonstrate the importance of early detection and appropriate treatment when treating TICAs due to their unpredictable nature.
The incidence of TICA is rare and accounts for less than 1% of all intracranial aneurysms.[
TICA is more common in the anterior circulation, and less than 10% of TICAs occur in the posterior circulation.[
There are few reports of traumatic PICA aneurysms such as the one described in this case study. A review of the English and Japanese language literature performed on December 3, 2021, revealed 12 reports describing 15 cases of PICA-TICA.[
The timing of TICA diagnosis was after the 7th day in nine cases, and aneurysms in six cases were identified within 1 day. Regarding the location of PICA-TICA, 12 of 15 cases were AMS to lateral medullary segment (LMS) near the brain stem. Direct surgery, such as a trapping bypass, was performed in eight cases, and endovascular treatment was performed in four cases. Overall, 5 patients (33%) had good outcomes (Glasgow Outcome Scales 4 or 5) and seven patients died. The untreated case (two patients) had a poor prognosis. There was no difference in prognosis depending on the time of rupture or the site of the aneurysm. The reason may be that there are only a few reports and publication bias.
In our review of PICA-TICA, there were five cases with vascular anomalies in the posterior fossa. There are also reports of the PICA starting immediately after the dural penetration of VA, as in the present case.[
Our patient also had SAH which was mostly confined to the posterior fossa, IVH, and mild ventriculomegaly on the initial CT. It was suspected that an intrinsic cerebral hemorrhage had occurred or that a traumatic cerebral aneurysm had ruptured. A cerebral CT angiogram was performed, but no vascular abnormality that could be a hemorrhage source of SAH or IVH was detected. Therefore, conservative treatment and imaging follow-up were performed for intracranial hemorrhage, and systemic treatment was administered for complicated pneumothorax, multiple fractures, and hypothermia.
The DSA performed 2 h after the cerebral CT angiogram showed that PICA-TICA had expanded to 11 mm. Because of the dominant PICA, it was likely under hemodynamic stress, and PICA might partially fix to the dura mater; therefore, it is possible that the external force of the trauma was applied to the origin of the PICA, resulting in a pseudoaneurysm.
In general, direct surgery such as clipping and trapping bypass and endovascular treatment such as parent artery occlusion, intra-aneurysm coil embolization, and stent-assisted coil, have been reported for the treatment of PICA-TICA.[
We encountered a case in which a patient with a vascular anomaly in the posterior fossa had IVH and SAH after a fall, and a late PICA-TICA, which was difficult to diagnose and treat.
PICA-TICA is often accompanied by IVH and SAH, and there are some reports of cases with a vascular anomaly of the posterior circulation. Since TICA is at risk of rapid growth and rupture, an early and appropriate diagnosis is important.
Patients’ consent not required as patient’s identity is not disclosed or compromised.
There are no conflicts of interest.
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