Early major recurrence of cerebral aneurysms after satisfactory initial coiling

Abstract

Background and purpose: Early major recurrence (EMR) of cerebral aneurysms treated by coiling has not been investigated. The purpose of this study is to characterize the frequency and risk factors of this phenomenon.

Materials and methods: A retrospective review was performed of consecutive patients who presented with ruptured and unruptured cerebral aneurysms and underwent coiling from July 2009 to June 2019 at a university hospital. We defined EMR as recurrence of the aneurysm greater than its initial size within the first 6 months of an initial satisfactory coil embolization. Patient demographics, clinical information, aneurysm characteristics, angiographic and technical details were reviewed.

Results: From July 2009 to June 2019, 338 aneurysms (190 unruptured aneurysms and 148 ruptured cerebral aneurysms) underwent coiling and satisfied our study criteria. Among these patients, 23 patients (19 ruptured and 4 unruptured aneurysms) were found to have recurrent aneurysm. Of those, 4 were found to have early major aneurysm regrowth occurring within 6 months after coiling (1.2%). The detection of the EMR was as early as 4 weeks and as late as 20 weeks after the initial coil embolization. The average detection time was 10 ± 7.2 weeks (mean ± SD, range:4-20 weeks). In each case, the recurrent aneurysm cavity was more than twice the initial size of presentation. All aneurysms with major recurrence were ruptured with low aspect ratios (dome height to neck ratio) and involved a communicating segment. All patients underwent successful retreatment of the recurrent aneurysm with good outcome.

Conclusions: Early major recurrence of treated aneurysms is a rare but important complication that harbors an impending risk of re-rupture. Early control angiography after endovascular coiling may be warranted for small ruptured aneurysms, even in cases in which the initial result seems technically satisfactory.

Keywords: Recurrence; endovascular coiling; ruptured aneurysm; subarachnoid hemorrhage.

Figure 1.

A flow chart of the study population (*: Recurrent aneurysms not meeting the criteria of early major recurrence).

Figure 2.

Coronal CT angiogram (a), 3D volume-rendered angiogram reconstruction (b) and 2D anteroposterior angiogram (c) showing a ruptured 8 × 5 mm posterior communicating artery aneurysm with 5 mm neck. The aneurysm was treated with balloon assisted coiling. A small remnant was left at the inferior neck due to difficulty of recannulating this pocket (d). The plan was for elective flow diversion after the patient’s acute hospitalization phase. While recovering in the rehabilitation center, the patient developed transient right face and arm weakness 1 month after her initial hemorrhage. CT angiogram revealed major recurrence of the coiled aneurysm, measuring approximately 17 × 9 mm with multiple lobulations that was confirmed by angiography (e). The patient was retreated with coils and flow diversion across the aneurysm (d).

Figure 3.

Coronal CT angiogram (a), 3 D volume-rendered angiogram reconstruction (b) and 2 D anteroposterior angiogram (c) showing a ruptured left posterior communicating artery aneurysm of 3.5 × 2 mm and 1.5 mm neck. Using balloon assisted coiling, the aneurysm was coiled with good occlusion (d). Repeat angiogram 6 weeks after the embolization in the setting of oculomotor nerve palsy showed major recurrence of the treated aneurysm, measuring 8 × 7 mm with a neck of 1.5 mm. The initial coil mass is noted displace postero-inferiorly by the coil mass (white arrow) (e). The recurrent aneurysm was treated using balloon assisted coiling with complete occlusion (f).

Figure 4.

Coronal CT angiogram (a), 3D volume rendered angiogram reconstruction (b) and 2D anteroposterior angiogram (c) showing a ruptured anterior communicating artery aneurysm measuring 3 × 2 mm with a 2 mm neck. Using balloon assisted coiling, the aneurysm was coiled with complete occlusion (d). Attempts to deploy further coils were unsuccessful because of coil herniation as well as dislodgment of the microcatheter from the aneurysm. Angiogram 3 months after embolization showed major recurrence of the previously treated aneurysm measuring 8 × 7 mm (e). The patient was retreated with balloon assisted coiling with complete occlusion of the aneurysm (f).

Figure 5.

Sagittal CT angiogram (a), 3D volume-rendered angiogram reconstruction (b) and 2D oblique angiogram (c) showing a ruptured 2 × 2 mm left posterior communicating artery aneurysm (white arrow in (a) and (b)). The aneurysm was coiled using balloon assisted coiling with satisfactory occlusion (d). Routine cerebral angiogram done at 20 weeks showed recurrent 4 × 3 mm posterior communicating artery aneurysm (white arrow) with a 1.2 mm neck (e) that was retreated with balloon assisted coiling (f).