Elsevier

World Neurosurgery

Volume 82, Issue 5, November 2014, Pages 714-721
World Neurosurgery

Peer-Review Report
Occipital Artery–Posterior Inferior Cerebellar Artery Bypass for the Treatment of Aneurysms Arising from the Vertebral Artery and Its Branches

https://doi.org/10.1016/j.wneu.2014.06.053Get rights and content

Objective

To report experience with 7 cases of intracranial aneurysms of the vertebral artery (VA) and its branches that were treated with occipital artery (OA)–posterior inferior cerebellar artery (PICA) bypass.

Methods

Over 4 years, 7 cases of intracranial aneurysms arising from the VA and its branches were treated with OA-PICA bypass. The clinical data, characteristics of aneurysms, and results of treatment were analyzed.

Results

There were 4 aneurysms that arose from the VA-PICA junction, 2 aneurysms that occurred at the distal PICA, and 1 aneurysm that occurred at the collateral artery from the distal end of the occluded VA to the ipsilateral PICA. OA-PICA bypass was performed before obliteration of the aneurysms in all patients. Of the 7 aneurysms, 4 were totally obliterated with surgery, 2 were treated with additional endovascular coiling or trapping, and 1 was partially obliterated by surgery and gradually disappeared during the follow-up period. Postoperative angiography revealed that the patency of the grafts was good in 6 patients. In 1 patient with an occluded bypass graft, multiple infarctions developed in the left cerebellum, but the patient had almost fully recovered after rehabilitation.

Conclusions

OA-PICA bypass with obliteration of the aneurysm is one of the optimal treatments for intracranial aneurysms that occur at the VA and its branches because it can preserve the perforators and distal blood flow from the PICA.

Introduction

The vertebral artery (VA) and posterior inferior cerebellar artery (PICA) are uncommon sites for intracranial aneurysms; <0.5%–3% of all intracranial aneurysms occur in this area (38). At the VA and PICA, there is a high incidence of both dissecting and fusiform aneurysms. Yamaura et al. (47) reported that 28% of intracranial aneurysms that occur at the VA and PICA are dissecting aneurysms and 13% are atherosclerotic fusiform aneurysms. Treatment of intracranial aneurysms of the VA and PICA is very difficult because of their location at the skull base near the brainstem and their unusual shapes.

Nonetheless, these difficult cases should be treated for the following reasons. The presenting clinical symptoms of patients who have intracranial aneurysms arising from the VA and PICA are subarachnoid hemorrhage (SAH) and brainstem ischemia 21, 23, 38, 46, 47. In addition, the rupture and rebleeding rates of these nonsaccular posterior circulation aneurysms are high. Mizutani et al. (29) reported that 71% of nonsaccular posterior circulation aneurysms rupture before treatment, and rebleeding occurs within 24 hours in 40.5% of these ruptured aneurysms. Saccular aneurysms of the posterior circulation, including the VA and PICA, tend to rupture more frequently than aneurysms of the anterior circulation 1, 43, 44. Finally, cranial nerve palsy occurs more frequently at the VA and PICA than in other locations 10, 47.

An aneurysm at the VA including the VA-PICA junction and one arising from the PICA have different characteristics. However, both types have a point of similarity in that they can diminish or obstruct the blood flow through the PICA during treatment. Multidisciplinary approaches including bypass surgery may be helpful in the treatment of these aneurysms. In the present study, we report our experience of 7 cases of an intracranial aneurysm located at the VA and its branches, including the PICA and an unusual collateral artery, that were treated with aneurysm trapping combined with distal revascularization.

Section snippets

Materials and Methods

We retrospectively reviewed patients who were treated for intracranial aneurysms arising from the VA and its branches, including the PICA and an unusual collateral artery, at our institution from January 2009 to December 2012. Patients were assessed according to the following inclusion criteria: 1) bypass treatment performed for intracranial aneurysms arising at the VA and its branches; 2) use of the occipital artery (OA) as the donor graft and the PICA as the recipient artery; and 3) all cases

Illustrative Case 1

A 45-year-old man (Case No. 2) was admitted to another hospital with a sudden severe headache. CT showed a diffuse SAH and intraventricular hemorrhage in the fourth ventricle. TFCA revealed a fusiform dissecting aneurysm in the fourth segment of the right VA just below the VA-PICA junction (Figure 1A); its longest length was 16.1 mm, and the largest diameter was 6.0 mm. The patient underwent stent-assisted coil embolization (Figure 1B). However, TFCA revealed coil compaction and recanalization

Revascularization for Treatment of Aneurysms Arising from the VA Involving the VA-PICA junction

Since the development of endovascular techniques, many aneurysms that arise from the VA involving the VA-PICA junction are treated using these methods 2, 11, 36. However, incomplete obliteration after endovascular treatment may occur to try to keep distal PICA flow. In addition, even if a residual aneurysm is not immediately noted after endovascular treatment, hemodynamic stress could induce coil compaction and recanalization of the aneurysm. Lv et al. (27) reported incomplete treatments in

Conclusions

We provide a retrospective review of 7 cases of intracranial aneurysms arising from the VA and its branches. These aneurysms are uncommon, and a standard treatment protocol is not yet fully established. On the basis of our experiences and previous reports, an OA-PICA bypass with trapping of the aneurysm is a viable option for the treatment of complex intracranial aneurysms arising from the VA and its branches. This procedure can result in total obliteration of the aneurysms, preventing

References (50)

  • N. Chalouhi et al.

    Endovascular treatment of proximal and distal posterior inferior cerebellar artery aneurysms

    J Neurosurg

    (2013)
  • N. Chalouhi et al.

    Treatment of posterior circulation aneurysms with the pipeline embolization device

    Neurosurgery

    (2013)
  • S.W. Chang et al.

    Posterior inferior cerebellar artery origin thrombosis with aneurysm of collateralized posterior meningeal artery presenting as subarachnoid hemorrhage: case report

    Neurosurgery

    (2009)
  • I.Y. Cho et al.

    A case of lateral medullary infarction after endovascular trapping of the vertebral artery dissecting aneurysm

    J Korean Neurosurg Soc

    (2012)
  • B.A. Coert et al.

    Surgical and endovascular management of symptomatic posterior circulation fusiform aneurysms

    J Neurosurg

    (2007)
  • R.W. Crowley et al.

    Operative nuances of an occipital artery to posterior inferior cerebellar artery bypass

    Neurosurg Focus

    (2009)
  • M. Czabanka et al.

    Vertebral artery-posterior inferior cerebellar artery bypass using a radial artery graft for hemorrhagic dissecting vertebral artery aneurysms: surgical technique and report of 2 cases

    J Neurosurg

    (2011)
  • A.L. D'Ambrosio et al.

    Far lateral suboccipital approach for the treatment of proximal posteroinferior cerebellar artery aneurysms: surgical results and long-term outcome

    Neurosurgery

    (2004)
  • J.D. Day et al.

    Cranial base approaches to posterior circulation aneurysms

    J Neurosurg

    (1997)
  • A.F. Ducruet et al.

    Reconstructive endovascular treatment of a ruptured vertebral artery dissecting aneurysm using the Pipeline embolization device

    J Neurointerv Surgery

    (2013)
  • G. Gacs et al.

    Peripheral aneurysms of the cerebellar arteries. Review of 16 cases

    J Neurosurg

    (1983)
  • J.-I. Hamada et al.

    Multimodal treatment of ruptured dissecting aneurysms of the vertebral artery during the acute stage

    J Neurosurg

    (2003)
  • J. Hamada et al.

    Reconstruction of the posterior inferior cerebellar artery in the treatment of giant aneurysms. Report of two cases

    J Neurosurg

    (1996)
  • K. Iihara et al.

    Dissecting aneurysms of the vertebral artery: a management strategy

    J Neurosurg

    (2002)
  • B.M. Kim et al.

    Incidence and risk factors of recurrence after endovascular treatment of intracranial vertebrobasilar dissecting aneurysms

    Stroke

    (2011)
  • Cited by (28)

    • The Intersection Between the Sternocleidomastoid and Splenius Capitis as the Anatomical Landmark to Facilitate Occipital Artery Harvest: A Retrospective Clinical Study

      2022, World Neurosurgery
      Citation Excerpt :

      The PICA-PICA bypass was more commonly used because an OA graft was not required. The complex course of the OA through the suboccipital muscles makes the harvest more complicated.1-7 Several techniques of OA harvest were proposed.

    • Subarachnoid Hemorrhage Due to Rupture of Vertebral Artery Dissecting Aneurysms: Treatments, Outcomes, and Prognostic Factors

      2021, World Neurosurgery
      Citation Excerpt :

      When the contralateral VA is hypoplastic and when the dissected segment contains the posterior inferior cerebellar artery (PICA) origin or the anterior spinal artery, neither internal nor surgical trapping is appropriate because the parent artery must be preserved. Such VADAs have been treated with surgical VA trapping with an occipital artery (OA)–PICA bypass,11,12 coil embolization with a neck-bridging stent,13-16 overlapping multiple stents,17 or flow diverter.18-20 Treatment decisions must take into account the positional relationship between the VADA and the PICA and the morphology of the contralateral VA or the posterior communicating artery.

    • Rerupture Following Flow Diversion of a Dissecting Aneurysm of the Vertebral Artery: Case Report and Review of the Literature

      2020, World Neurosurgery
      Citation Excerpt :

      The construct demonstrated compaction with recanalization of the aneurysm after 9 months, so the authors performed an OA-PICA bypass with proximal clip occlusion of the right PICA using a far lateral approach followed by endovascular trapping of the dissected segment of the VA 2 days after surgery. This technique resulted in a good outcome at 6-month follow-up.38 Czabanka et al39 introduced a VA-PICA bypass with radial artery interposition graft and trapping of the aneurysm as an alternative to PICA-PICA and OA-PICA bypass for hemorrhagic dissecting aneurysms that cannot be treated with endovascular occlusion.

    View all citing articles on Scopus

    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    View full text