These fragile broad-based aneurysms have a propensity to rupture with minimal manipulation during surgical or endovascular explorations because, unlike saccular aneurysms, they lack all layers of the arterial wall. Aneurysm trapping with Extra intracranial bypass surgery is a safe and durable treatment 1).
His grim prognosis is based on results that indiscriminately group all blister aneurysms together without taking into account the heterogeneous appearance of these lesions.
Owing to their peculiar features and rare occurrence, ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery are challenging by both surgical and endovascular approaches and their proper management is uncertain.
Szumuda et al aimed to define the currently optimal treatment of ruptured BBAs in terms of mortality, outcome, rebleeding, and recurrence.
An in-depth search of electronic databases, gray literature and internet resources for ruptured BBAs was performed and complemented by data retrieval during neurosurgical congresses. Clinical and radiological characteristics, intervention details, outcomes, and the impact factor of the source journal were pooled.
The pooled cohort comprised 311 patients. Neither surgical nor endovascular methods had an impact on clinical outcome, aneurysm regrowth, remote bleeding, or complication rate. By contrast, aneurysm clipping was a predictor of intraoperative bleeding (OR 6.5; 95% CI 1.2 to 34.3), and stent-assisted coiling increased the likelihood of a second treatment (OR 4.1; 95% CI 1.3 to 13.1), its conversion to another modality (OR 4.7; 95% CI 1.4 to 16.0), and incomplete aneurysm obliteration (OR 2.6; 95% CI 1.0 to 6.6). Higher impact journals were more likely to publish papers on endovascular techniques, particularly flow diverter stents.
None of the methods is unequivocally superior. Considering its inefficiency, stent-assisted coiling should be undertaken with caution. A time-delimited systematic review is needed to establish the most accurate treatment for ruptured BBAs 2).
A retrospective review of 10 patients allowed a division into 4 distinct subtypes: Type I (classic), Type II (berry-like), Type III (longitudinal), and Type IV (circumferential). These subtypes may at times be progressive stages in the arterial anomaly, and could represent a continuum. Each subtype described in this paper presented its own pitfalls and required specific surgical adaptations. Upon reviewing the literature the authors retained 35 studies involving a total of 61 cases of blister aneurysms, and all cases were able to be classified into 1 of these 4 distinct subtypes.
Although they share some common characteristics, blister aneurysms may be divided into distinct subtypes, suggestive of a continuum. Such a classification with a detailed description of each type of blister aneurysm would allow for better recognition to anticipate complications during intervention and better assess the different treatment strategies according to the subtypes 3).
A 29-year-old man presented with subarachnoid hemorrhage and a ruptured dorsal variant internal carotid artery aneurysm. Despite a technically successful treatment with a single FDS, a second catastrophic hemorrhage occurred during the course of his hospitalization.
This case highlights the risk of hemorrhage during the period after deployment of a single FDS. Ruptured aneurysms, especially of the blister type, are at risk for rehemorrhage while the occlusion remains incomplete after flow diversion 4).