Posteroinferior Cerebellar Artery (PICA) Fusiform Aneurysm Ruptured Related with a Pure Arterial Malformation: Case Report and Technical Note (NBCA Embolization under Roadmap-Fluoroscopy)

Background: The pure arterial malformation (PAM) lesion has been recently described as a vascular pathology characterized by the sole presence of coiled, sometimes ectatic, arterial loops. 2% of the fusiform aneurysms are located in the vertebral-posterior inferior cerebellar arteries. Case Presentation: A 60 years old female with subarachnoid hemorrhage was diagnosed with a fusiform aneurysm in the right PICA related with a PAM in the digital subtraction angiography (DSA). With a negative super-selective Wada test, the patient was treated with embolization of the two lesions and the PICA for being in the same arterial territory with adhesive embolic liquid under roadmap fluoroscopy technique. The patient had a satisfactory clinical evolution and no added neurological deficit, so she was discharged 3 days after the treatment. Conclusion: These two vascular lesions located in the same artery are very rare and more in the PICA territory. It is important to make the best decision to treat them because of the potential complications; that’s why the procedure was supported with super-selective Wada test and neuromonitoring of the PICA territory. The injection of the mixture of NBCA and Lipiodol® under roadmap fluoroscopy is very safe.


Background
The pure arterial malformation (PAM) lesion has been recently described as a vascular pathology characterized by the sole presence of coiled, sometimes ectatic or arterial loops [1]. These lesions are commonly mistaken for aneurysms or arteriovenous malformations [2].
Dolichoectatic arteries and fusiform aneurysms are related to arteriopathies and connective tissue diseases, and just 2% of the intracranial aneurysms are located in the vertebral-posterior inferior cerebellar arteries (PICAs) [3].
N-butyl cyanoacrylate (NBCA) is commonly used liquid embolic agent in the endovascular treatment of cerebrovascular and peripheral vascular pathologies.
Although NBCA is most commonly known as an endovascular treatment option for cerebral arteriovenous malformation, neurointerventionalist has begun to utilize cyanoacrylate glues for several vascular brain pathologies [4] [5].
Our objective is to present two rare types of arterial malformations in the same artery and their successful treatment with endovascular therapy by using a mixture of NBCA and Lipiodol® , guided with roadmap fluoroscopy to achieve the proper embolization with good visualization and safe injection.   The procedure was performed as follows: with the patient awake, analgesia and local anesthesia, neurophysiologic monitoring, super-selective Wada test with 1cc propofol injected in the right PICA obtaining as result, no neurophysiological deficit and clinically did not develop a Wallenberg syndrome.

Case Report
We proceeded to embolize both lesions and the right PICA with NBCA and Lipiodol®. The patient returned to the ICU and she had a satisfactory clinical evolution and no added neurological deficit, so she was discharged 3 days after the treatment. In the follow up as outpatient 5 months after the procedure she had a grade 2 mRS.

Management
We approached the right femoral artery with a 6F sheath. For the right vertebral hypoplastic artery was used a 5F Chaperon® for the coaxial system with a 1.5 Headway Duo® microcatheter and a Xpedion TM 10 microwire for the super-selective catheterization of the right PICA under roadmap fluoroscopy and done a super-selective angiogram (Figure 2(a)) provocative Wada test was performed with 1 cc of propofol injected in the right PICA supported with neuromonitoring and physical exploration of the patient. The result of the test was negative for a neurological deficit. A load dose of dexamethasone was given intravenously, the microcatheter in optimal position was flushed with 10 cc of 5% glucose solution, the embolization was done with a dilution 1:8 of NBCA and Lipiodol® under roadmap fluoroscopy technique in a Philips Allura. In Figure 3: we see the microcatheter tip in the second segment of the PICA and the beginning of the embolization as well as the radiopacity, of the NBCA + Lipiodol® with this technique and finally the detached of the microcatheter.
In the ending rounds of the DSA showed total exclusion of the aneurysm, PAM and the right PICA occlusion (Figure 4(a)); the parenchymogram demonstrated no vascular defects (Figure 4(b)).
The femoral artery was closed with Angioseal® 6F and the control non contrast CT scan did not demonstrate hemorrhage or ischemic stroke, the liquid embolic material with no artifact ( Figure 5).

Discussion
In pure arterial malformations the overlapping, dilated and tortuous trajectory are coil-like appearance in all population ages and may have genetic, infectious, inflammatory, immunological o degenerative predisposing factors that may cause or contribute to the formation and/or progression of the arteriopathy. The appropriate characterization of the vasculopathy architecture is paramount important for choosing the best treatment and prognosis varies depending on the type of the vascular anomalies [6].
Aneurysms arising from the PICA distal to the origin from the vertebral artery are rare, represent 0.5% -3% of all intracranial aneurysms. The fusiform geometry is considered when they had no discernible neck [7]. And PICA aneurysms are most commonly discovered when patients present a subarachnoid hemorr- The glue composition depends on the hemodynamic characteristics of the targeted lesion to calculate the viscosity of the embolic [12] and the radiopacity adding tantalum or tungsten powder to increase the visibility of the mixture in the conventional fluoroscopy technique [13] [14] [15].

Conclusions
There is a low incidence of a fusiform and a pure arterial malformation in the same intracranial arterial territory. The endovascular technique is a secure procedure, because during the treatment you can do neurological provocative test and decide the most suitable management.
The utilization of the roadmap fluoroscopy technique during the injection of the mixture of NBCA and Lipiodol®, gives the operator the visibility of the radiopacity, advance and penetration of the glue as well the reflux at the microcatheter tip without adding tantalum and tungsten.