Editorial on a paper entitled “Combined suture and clipping for the reconstruction of a ruptured blister-like aneurysm”

Abstract

EditorialBlister-like aneurysms are small, extremely fragile aneurysms at non-branching sites of cerebral blood vessels. The prevalence among all aneurysms is around 0.5% and the prevalence among ruptured aneurysms is 1.2%. In contrast to saccular aneurysms, they consist of only a thin layer of adventitia covered by a platelet plug, which covers a defect in the intima and media of the vessel wall. The underlying pathogenesis has been discussed to be atherosclerosis, hemodynamic stress, or dissection. Often, the vessel wall of the presumably intact blood vessel around the blister-like aneurysm is also affected and fragile. Thus, (re-) rupture of a blister-like aneurysm, both during microsurgical or endovascular treatment, may leave a large defect behind or may even destroy large parts of the circumference of the vessel wall.The most prominent site for blister-like aneurysms is the supraclinoid internal carotid artery, where blister-like aneurysms were first described by Sundt and Murphey [6] and later by Nakagawa et al. [3]. Since then, blister-like aneurysms have been described throughout the cerebral vasculature. Often, their treatment is complicated by the proximity of perforating branches, most importantly the anterior choroidal artery in the case of blister-like aneurysms along the internal carotid artery.Often, treatment is complicated by the fact that the proper diagnosis of a blister-like aneurysm and pre-therapeutic assessment of the extent of the arterial wall involvement may be impossible by conventional imaging modalities. Due to the small size of the blister-like aneurysms, diagnostic angiography still carries the highest diagnostic reliability. However, it only reveals the aneurysm lumen and not the aneurysmal wall, leaving the correct pre-hoc diagnosis to the experience and level of suspicion ('gut feeling') of the treating neurovascular team. Even in the most experienced neurosurgical hands is the rate of failed preoperative diagnosis considerably high [4].The fragility of these lesions and their broad neck make them extremely difficult to treat, both through microsurgical and endovascular techniques. A direct conventional attack of these lesions either from the extravascular side by clipping or from the endovascular side by coiling has been associated with a high risk of intraoperative rupture, resulting in large defects in the vessel wall. These large defects often force the surgeon to sacrifice the affected vessel segment. Treatment becomes most risky if blister-like aneurysms are not diagnosed beforehand and the surgeon-who may assume a straightforward clipping case-unexpectedly faces these malignant lesions without being properly prepared. A recent report from the UCSF group impressively confirmed the difficulty in treating these patients surgically: The intraoperative rupture rate was sixfold higher than that of a saccular aneurysm and intraoperative aneurysm rupture doubled the risk of poor outcome [4]. This is the reason why endovascular techniques seem to be very attractive, especially f...

Endovascular Treatment of Intracranial Aneurysms

“…Stand-alone coiling is feasible for IAs with dome-to-neck ratios > 2.0 (Figure 1), excluding blood blister-like aneurysms, due to the wide neck, small size, and weak wall of these aneurysms, which pose a high risk of perforation [27]. Unassisted coiling is not recommended in large aneurysms with wide neck and low dome-to-neck ratio due to the high risk of poor outcomes [28].…”

Current status of the treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery: A review

“…Because BBAs of the supraclinoid ICA are very fragile and have a tendency to progress in size over a short period, primary coiling may be dangerous, given the lesion's wide neck, small size and weak wall that lacks collagenous tissue, particularly in the acute period 56. Occasionally, when some patients waited for several weeks until the late period, the BBAs were treated with coil embolization because at this time, the ruptured BBAs may become spherical and covered by a thick clot, which eliminates the issue of wall fragility in this false aneurysm.…”