A novel treatment of a patient with a giant ruptured middle cerebral artery aneurysm by acute coiling followed by scheduled Pipeline flex placement

Abstract

Objective

Flow diversion in the acute phase of aneurysm rupture or giant aneurysm is limited by the need for dual antiplatelet therapy and the risk of delayed aneurysm rupture. Here, the authors report a scheduled flow-diversion concept for the endovascular treatment of a giant intra-dural aneurysm.

Methods

A 54-year-old female patient with a ruptured giant middle cerebral artery aneurysm underwent coiling in the acute phase following 1-month scheduled Pipeline flex placement.

Results

The acutely ruptured giant middle cerebral artery aneurysm was treated by flow diversion scheduled at 1 month after conventional coiling. The patient tolerated this treatment strategy well without any neurological deficits after the procedure and during the 3-month follow-up. The aneurysm showed nearly complete obliteration on 3-month follow-up angiogram, and a 6- to 12-month follow-up was scheduled.

Conclusions

This strategy may be considered as an option in patients presenting with ruptured or unruptured giant intra-dural aneurysms.

Introduction

Flow-diversion treatment has been shown to be a curative method for giant aneurysms with parent artery preservation.¹ However, flow diversion in the acute phase of aneurysm rupture or giant aneurysm is limited by the need for dual antiplatelet therapy and the risk of delayed aneurysm rupture.² One potential treatment paradigm is staged flow diversion after coiling in the acute phase to reduce early rebleeding risk and shrink the aneurysm volume. The aneurysm will then be able to tolerate dual antiplatelet therapy and flow diversion treatment. We treated an acutely ruptured giant middle cerebral artery (MCA) aneurysm by flow diversion scheduled at 1 month after conventional coiling because most of the active healing of the post-coiled intracranial aneurysm occurs within the first month (Figures 1 and 2). This is the first proposal of a 1-month scheduled flow-diversion concept, which is based on our greater understanding of delayed bleeding mechanisms of giant aneurysms.^3,4

Figure 1.

(a) Computed tomography (CT) scan shows a subarachnoid haemorrhage and a giant mass in the right Sylvian fissure (arrowhead). (b) Frontal view of right internal carotid artery (ICA) angiogram shows a giant aneurysm of the right middle cerebral artery bifurcation (arrow). (c) Frontal view of the right ICA angiogram shows the aneurysm coiled using the ‘double-catheter technique’, with special attention to the medial side of the aneurysm, where the rupture site was according to CT examination (arrow). (d) Lateral view of the right ICA angiogram after embolization shows that more than half of the aneurysm was coiled (arrow).

Figure 2.

(a) Lateral view of the right ICA angiogram 1 month later shows more than half the aneurysm has been thrombosed (arrowhead). (b) Road map of working angle shows the Pipeline advanced to the target zone (arrowhead). (c) Unsubtracted image shows the Pipeline device (arrowhead) and coil mass. (d) Frontal view of the right ICA angiogram at 3-month follow-up after Pipeline placement shows the subtotal occlusion of the aneurysm (arrow) and patency of the middle cerebral artery branches.

Case presentation

A 54-year-old female patient presented with severe headache and vomiting for 1 day. A computed tomography (CT) scan confirmed a subarachnoid haemorrhage (SAH) and a mass at the Sylvian fissure (Figure 1(a)). On presentation, the Hunt and Hess grade was I. A CT angiogram showed a giant aneurysm (24 mm × 24 mm in size) locating in the MCA bifurcation. We decided to coil the aneurysm partially in the acute phase, followed by a scheduled Pipeline flex placement 1 month later. The patient’s consent and approval of the ethics committee of our hospital were obtained for this treatment.

During the initial coiling procedure, the aneurysm was successfully treated with the ‘double-catheter technique’ under general anaesthesia (Figure 1(b)–(d). The intention was not to achieve complete occlusion but to provide short-term protection from rebleeding and to shrink the volume of the aneurysm. Angiographic occlusion immediately after coiling showed incomplete occlusion. During the 1-month interval, the patient’s course was uneventful.

One month later, the patient was premedicated with aspirin 100 mg/day and clopidogrel 75 mg/day for 5 days. Under general anaesthesia, a 5 F Navien catheter (Medtronic Neurovascular, USA) was advanced to M1 through an 8 F envoy guiding catheter (Cordis, Santa Clara, CA). A headway duo microcatheter (MicroVention, Inc., Aliso Viejo, CA) was navigated through the aneurysm to the distal MCA. A 150 cm Maskman catheter (Medtronic) was exchanged using a 300 cm 0.014in Transend microguidewire (Boston Scientific, Marlborough, MA). A 3.0 mm × 35 mm Pipeline Flex (Medtronic Neurovascular, USA) was placed to cover the aneurysm neck (Figure 2(a)–(c)). The patient’s course was uneventful, and she discharged on day 3 post procedure. A 3-month follow-up angiogram showed subtotal occlusion of the aneurysm, and the patient was doing well (Figure 2(d)). A 6- to 12-month follow-up angiogram was scheduled.

Discussion

Our study demonstrates that a 1-month scheduled flow-diversion treatment for a giant MCA aneurysm after coiled embolization in acute SAH is a safe and effective strategy. We consider this a remarkable achievement, given the giant ruptured MCA aneurysm. This strategy is valuable for ruptured and unruptured intra-dural giant aneurysms, as it allows for transitioning from the acute phase to the subacute phase, from a giant aneurysm to a small or large aneurysm, where dual antiplatelet and flow-diversion therapy are safer. McAuliffe et al. reported that two aneurysms treated with the Pipeline alone re-ruptured in the acute phase, leading to death in both cases.² Other studies have reported the use of staged flow diversion for the treatment of acutely ruptured aneurysms. Chalouhi et al. reported that four patients had staged coiling followed by Pipeline treatment for ruptured aneurysms.⁵ Nossek et al. reported the use of staged coiling followed by Pipeline treatment of two ruptured aneurysms with good results.⁶ Brinjikji et al. reported staged treatment of ruptured complex and giant intracranial aneurysms with coiling and flow-diverter treatment during 16 weeks.⁷ In these studies, they failed to establish a set protocol. This is first report to provide a standard technique of scheduled flow-diversion therapy where the goal was protection from rebleeding.

In our experience, it is important that the goal of this combined approach is to achieve just enough packing density to prevent early rebleeding and to shrink the aneurysm volume by more than a half. We paid special attention to identifying the most likely point of rupture, and targeted coiling with special emphasis in packing, thus protecting the rupture site. The ‘double-catheter technique’ can distribute coils evenly in aneurysms without confining the coils to one part of the aneurysms or risking coil prolapse. The risk of coil prolapse was demonstrated in Brinjikji et al.’s patient who suffered an internal carotid artery (ICA) occlusion, most likely related to overpacking the aneurysm, which compromised the parent artery.⁷

We defined the interval between coiling and flow diversion as 1 month. Histolopathological studies in coiled human and experimental aneurysms suggest that during the first month post coiling, thrombus formation and active inflammation occur within the aneurysm dome.⁸ Recanalization of intracranial aneurysms following endovascular coiling remains a frustratingly common occurrence. The rate of complete obliteration with coils is low in large and giant aneurysms treated with coils.⁹ Prior studies have demonstrated that aneurysm recanalization often occurs early, within 6 months of aneurysm coiling.¹⁰ Brinjikji et al. observed one case of rebleeding of an 11 mm supraclinoid ICA aneurysm 9 months after coil embolization.⁷ In Lv et al.’s study, delayed aneurismal bleeding complications usually occurred within the first month after giant aneurysm flow-diversion treatment.³ These are the reasons why we scheduled flow diversion at 1 month after coiling embolization.

Limitation

This is a single report, and so it is difficult to determine whether our treatment strategy would be superior to a single-session strategy that involved either concomitant coiling or flow diversion only for giant intra-dural aneurysms. On the other hand, we did not perform routine platelet testing prior to flow-diversion treatment. However, in a subgroup analysis of the International Retrospective Study of Pipeline Embolization Device registry, the use of platelet testing had been reported to be associated with higher odds of morbidity and mortality.¹¹ There is no evidence to prove that preoperative platelet testing can improve outcomes in patients treated by Pipeline flow-diversion therapy.

Conclusions

One-month scheduled flow diversion following coil embolization of ruptured or unruptured giant aneurysms may be safe and effective. Further studies are needed to evaluate if this is an ideal treatment strategy for giant intra-dural aneurysms.