Expanding Endovascular Therapy of Very Small Ruptured Aneurysms with the 1.5-mm Coil

Abstract

Background: Very small ruptured aneurysms (≤3 mm) demonstrate a significant risk for procedural rupture with endovascular therapy. Since 2007, 1.5-mm-diameter coils have been available (Micrus, Microvention, and ev3), allowing neurointerventionalists the opportunity to offer patients with very small aneurysms endovascular treatment. In this study, we review the clinical and angiographic outcome of patients with very small ruptured aneurysms treated with the 1.5-mm coil. Methods: This is a retrospective cohort study in which we examined consecutive ruptured very small aneurysms treated with coil embolization at a single institution. The longest linear aneurysm was recorded, even if the first coil was sized to a smaller transverse diameter. Very small aneurysms were defined as ≤3 mm. Descriptive results are presented. Results: From July 2007 to March 2015, 81 aneurysms were treated acutely with coils in 78 patients presenting with subarachnoid hemorrhage. There were 5 patients with 3-mm aneurysms, of which the transverse diameter was ≤2 mm in 3 patients. In all 5 patients, a balloon was placed for hemostatic prophylaxis in case of rupture, and a single 1.5-mm coil was inserted for aneurysm treatment without complication. Complete aneurysm occlusion was achieved in 1 patient, residual neck in 2, and residual aneurysm in 2 patients. Aneurysm recanalization was present in 2 patients with an anterior communicating artery aneurysm; a recoiling attempt was unsuccessful in 1 of these 2 patients due to inadvertent displacement and distal coil embolization, but subsequent surgical clipping was successful. Another patient was retreated by surgical clipping for a residual wide-neck carotid terminus aneurysm. One patient died of ventriculitis 3 weeks after presentation; all 4 other patients had an excellent outcome with no rebleed at follow-up (mean 21 months, range 1-62). Conclusion: The advent of the 1.5-mm coil may be used in the endovascular treatment of patients with very small ruptured aneurysms, providing a temporary protection to the site of rupture in the acute phase. If necessary, bridging with elective clipping may provide definitive aneurysm treatment.

Coil migration during or after endovascular coiling of cerebral aneurysms

“…The use of small coils, undersizing coils relative to the maximal aneurysm size, and inserting or removing the first or last coil were associated with migration in our series. Although the increasing availability of small coils has allowed treatment of small aneurysms, use of these smaller coils could explain the increased migration risk as a result of the challenges of small aneurysm catheterization, and less purchase and stability of the microcatheter when treating smaller aneurysms 23 24. The size, type, and configuration of coils deployed at the neck of the aneurysm, as well as instances of very short and exceptionally soft coils, may be an important factor in determining the risk of migration.…”

Early major recurrence of cerebral aneurysms after satisfactory initial coiling

“…17 , 18 However, in contrast to what is commonly known that larger aneurysms, wide necks and bifurcations aneurysms have higher risk of recurrence, 16 most aneurysms with early major recurrence in our series were small and had small necks and were located at a communicating segment. These factors are generally associated with greater technical difficulty to treat and higher complication rates 19–21 (Figures 2 to 5).…”

History of Neurointervention

“…52 Since ISAT, a wide variety of coils have come to market, each with different properties that render them advantageous in specific scenarios. 20,[53][54][55] Although coiling would eventually replace clipping as the standard of care for certain intracranial aneurysms, aneurysms with complex morphology such as terminal, wide necked, and large aneurysms remained a problem. Balloon-assisted coiling (BAC) and stent-assisted coiling (SAC) were developed to improve outcomes in this group.…”