Stent-assisted coiling of posterior inferior cerebellar artery aneurysm complicated by arterial avulsion

Abstract

Background

Rapid development of new devices and techniques in endovascular neurosurgery allows treatment of complex intracranial vascular lesions. These treatments, however, are not without risk. We report a case of unusual vascular laceration during stent-assisted coiling of a posterior inferior cerebellar artery (PICA) aneurysm.

Case presentation

A 75-year-old female with a recurrent, previously coiled PICA aneurysm developed avulsion of the parent vessel followed by fatal bleeding while an attempt was made to place a microcatheter across the aneurysmal neck for stent-assisted coiling.

Conclusions

Pathological examination was performed to understand the mechanism of the rupture. The most likely mechanism was straightening of the significant vascular tortuosity, excessive tension on the vessel origin and avulsion upon advancement of the microcatheter over the microguidewire.

Background

Intracranial hemorrhage secondary to intraprocedural rupture is a known potential complication of endovascular aneurysmal treatment. This occurs in approximately 0.5% and 4.1% of ruptured and unruptured aneurysm treatments, respectively. Associated mortality and morbidity is in the range of 29% and 38% in unruptured and ruptured aneurysms, respectively.¹ Most reported ruptures are secondary to punctures by microguidewires/microcatheters and during coil deployment.² With the development of more advanced techniques such as balloon- or stent-assisted coiling, more challenging cases may be attempted by the operators, which may lead to a higher rate of complications. In addition, for procedures in which a stent is thought to be required, the additional preparation with antiplatelets may have devastating effects if there is an intraprocedural hemorrhage.

Case presentation

A 75-year-old female presented with a recurrent posterior inferior cerebellar artery (PICA) aneurysm 18 months after initial coiling for subarachnoid hemorrhage (Figure 1). Past medical history included hypertension, rheumatoid arthritis and abdominal aortic aneurysm repair.

Figure 1.

Initial subarachnoid hemorrhage demonstrated on the unenhanced axial computed tomography brain images (a) and (b) mostly in the posterior fossa, but also supratentorially, with intraventricular hematoma extension. Digital subtracted cerebral angiogram demonstrates the wide-necked right posterior inferior cerebellar artery aneurysm (c) and final result post endovascular coiling (d).

Investigations

After discussing therapeutic options with the neurointerventionalists, and reviewing risks and benefits with the patient, it was decided to randomize the patient in the Stenting in the Treatment of Aneurysm trial, a study comparing stent-assisted coiling with regular coiling with or without balloon assistance.³ The patient was allocated to the stenting arm and was started on aspirin and Plavix preprocedure.

Treatment

The recurrent PICA aneurysm had a wide neck and measured 4.5 × 1.9 mm (Figure 2). The parent vessel was an azygous right PICA supplying both cerebellar hemispheres.

Figure 2.

Digital subtracted cerebral angiogram demonstrating the recurrence of the previously coiled right posterior inferior cerebellar artery (PICA) aneurysm (a). The tortuosity of the PICA (b) is straightened in (c) with placement of the microcatheter and in (d) with the addition of a Traxcess-14 “buddy” microguidewire. The Scepter XC balloon could not be placed in the PICA and after attempting to place a Prowler Select Plus microcatheter in the PICA, tension was felt and check angiography demonstrated contrast extravasation (e). Rupture was managed with balloon inflation; however, there was ongoing contrast extravasation at one hour 30 minutes after initial rupture (f). This was treated with sacrifice of the right vertebral artery by coiling and placement of two Amplatzer vascular plug devices in the proximal vertebral artery (g). Final-check angiogram shows stasis in the distal right vertebral artery and no evidence of ongoing extravasation (h). Computed tomography brain performed in the angiography room demonstrated extensive subarachnoid hemorrhage (i), and this was managed by immediate insertion of bilateral extraventricular drains in the angiography suite (j).

The preprocedural treatment plan was balloon-assisted coiling of the recurrent aneurysm and secondary stent placement across the aneurysmal neck.

To access the aneurysm, a coaxial system was used with a 7 Fr BALT (Balt, France) guiding catheter in the right subclavian artery and a 6 Fr FargoMax (Balt, France) in the right V2 segment. An attempt was made to place a Scepter XC balloon (Balt, France) over a Traxcess microguidewire (Microvention, USA) into the right PICA without success because of marked PICA tortuosity. The balloon was repositioned in the distal vertebral artery. An SL-10 microcatheter (Stryker, USA) on a Traxcess 14 microguidewire was used to engage the PICA and used as a “buddy system” to attempt positioning the balloon in the PICA. The microguidewire was navigated into the PICA, but the balloon could not be positioned and was repeatedly bulging into the vertebral artery. The microguidewire could not be advanced further for more robust support because of vessel tortuosity.

The balloon was removed and a Prowler Select Plus microcatheter (Microvention, USA) was used with the intention to place it in the PICA to deliver the stent. The microcatheter could not advance into the PICA with resistance felt by the operator. Check angiography depicted contrast extravasation, and the patient developed hemodynamic changes compatible with rupture (Figure 3).

Figure 3.

Magnetic resonance scan at 24 hours postprocedure demonstrates high diffusion-weighted imaging (a) and (b) foci with corresponding low apparent diffusion coefficient signal (not shown) affecting both cerebellums in keeping with acute infarctions.

The balloon was immediately inflated in the right vertebral artery and the heparin reversed. An extraventricular drain was inserted immediately and angiography demonstrated ongoing extravasation upon balloon deflation at one hour 30 minutes from rupture. It was decided to sacrifice the right vertebral artery with coils positioned across the PICA origin and two Amplatzer vascular plug devices (St. Jude Medical, Belgium) in the right cervical vertebral artery. Final angiography confirmed stasis in the right vertebral artery and no further extravasation. The patient was kept intubated and transferred to the intensive care unit (ICU).

Outcome and follow-up

Immediate computed tomography scan demonstrated extensive subarachnoid hemorrhage and hydrocephalus. Follow-up MRI at 24 hours showed additional acute, bilateral inferior cerebellar and vermian ischemic infarctions. After discussion with the family, a do-not-resuscitate form was signed and the patient died of cardiac decompensation two days later.

An autopsy was performed, showing a transmural defect at the origin of the right PICA that was directly opposite the origin of the aneurysm (Figure 4). The elongated vessel laceration suggested a tractional mechanism leading to rupture, rather than a direct puncture of the artery.

Figure 4.

Postmortem examination was performed with evidence of acute subarachnoid hemorrhage in (a); more detailed images depicting the right vertebral artery, posterior inferior cerebellar artery (PICA) and the coiled aneurysm in (b) and (c). The site of rupture (d) is seen directly opposite the origin of the aneurysm and together with the elongated shape led us to believe that this was due to excessive traction on the PICA with straightening causing avulsion at its origin and leading to rupture.

Discussion

Intraprocedural perforations during endovascular aneurysmal treatment have been previously reported; however, only one case of vessel avulsion has been described in which the tip of the microguidewire was stuck within the vessel and the avulsion caused when pulling back on the wire.⁴ To our knowledge, partial avulsion secondary to straightening and traction of a tortuous vessel as in this case report has not been described. It is very important to understand the mechanism, distinguish this from other causes and use it as a learning experience to avoid it in the future. In our judgment, what led to the rupture is the fact that the patient had a tortuous PICA vessel and we distorted its anatomy by using a higher-profile microcatheter in an attempt to place the stent. This resulted in increased traction at the origin of the vessel and when we tried to advance the Prowler catheter over the microguidewire, there was further increased tension and stretch on the vessel wall that led to the rupture.

Management of intraprocedural hemorrhage is important, and there have been previous papers describing this as well as a checklist.⁵ The acute rupture management in this case was within accepted international standards.

Learning points

• The usual cause of intraprocedural hemorrhage during embolization is vessel perforation caused by microguidewires, microcatheters and during coil deployment (usually the first framing coil).

• Intraprocedural hemorrhage can also be caused via a traction and straightening mechanism leading to partial avulsion at the origin of an artery, as shown in this case.

• It is important to not distort the normal anatomy when attempting to place devices, especially if attempting a “buddy” technique, a higher profile microcatheter, a balloon or a stent, which is stiffer, as they may cause increased traction at the vessel origin, stretch on the vessel wall and cause rupture.

• Acute management of intraprocedural rupture is important, and pertinent points to consider are hemorrhage control with balloon inflation, continued aneurysm packing, anticoagulation reversal, clinical examination, and neurosurgical and ICU team involvement.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.