Wide neck cerebral aneurysms are difficult aneurysms to be treated either by surgical or endovascular approach [18]. Endovascular treatment of this type of aneurysm has been challenging for many reasons. Apart from coil protrusion and thrombo-embolic complications due to neck width, several branches arise from the neck, and may cause branch occlusion during coiling. In addition, a wide neck has a higher risk of aneurysm recanalization [19]. To overcome these concerns, various techniques have been developed: BAC, SAC, FD, and intrasaccular flow disruption [19].
We retrospectively reported a series of 40 WNAs to evaluate the safety and efficacy of endovascular treatment. Different techniques were reported in the treatment of cerebral WNAs-like simple coiling, double-microcatheter technique, BAC, SAC, and FD. The clinical and radiological outcomes of these cases were assessed at a 1-year follow-up. We found that the initial angiographic occlusion was significantly related to the type of intervention. The only aneurysm that had residual neck was reported with simple coiling treatment, otherwise complete occlusion was reported in other treatment modalities.
Our results are relatively different from the large study conducted by Chung and colleagues [13] who reported immediate complete occlusion rates of SAC, double-catheter coiling, and BAC embolization were 63.8%, 46.7%, and 63.2%, respectively. The differences could be attributed to our small sample size.
Over the past two decades, the initial results in the literature review showed relatively lower rates of complete occlusion, however, the improvements in neurovascular stent techniques improve the treatment of complex intracranial aneurysms [20, 21]. The Matrix and Platinum Science Trial conducted by Hetts and colleagues [22] reported complete occlusion and subtotal occlusion of SAC and coiling alone, in the treatment of unruptured cerebral aneurysms, of 45.7% and 62.8%, respectively.
King and colleagues [23] also compared two types of SAC and the initial and final complete occlusion were reported in 53% and 69%, respectively. In addition, the Enterprise type showed a higher rate of complete occlusion at follow-up. In a recent multicenter study [24] of SAC including 162 aneurysms (97.5% were wide-necked), the reported initial and long-term complete occlusion rates of 72.8% and 81.5%, respectively. These results are relatively similar to our study as the complete occlusion rate was found in 92.5% of aneurysms.
Our results also agreed with other studies; as in the USA trial [25], using the stent technique, complete and adequate occlusions were obtainable in 12 months 88.2% and 96.1%, respectively. Cagnazzo and colleagues [26] also reported in their study the long-term complete or near-complete aneurysm occlusion of 95.4% [26].
Regarding FD, a recent meta-analysis conducted by Abdel-Tawab and colleagues [27] concluded a complete occlusion rate of 82.4% in posterior circulation aneurysms and 77.5% in the anterior circulation aneurysm. The rate of complete aneurysm occlusion was 82.1% at 12 months, which is relative to what we reported in our results.
We had no mortality in our patients and the peri-procedural complications rate was relatively low (20%). These findings are similar to Gory [9], who reported a low rate of overall peri-procedural complications as they used the Solitaire device and found a complication rate of 12.7%. Another meta-analysis showed the same rate of peri-operative complications as they reported 20.2% and 13.1% in patients treated with SAC and coiling, respectively [28].
In our study, thrombus formation occurred in one patient treated with SAC and was managed with balloon dilatation and stenting. King and colleagues [23] reported near-similar rates of thrombo-embolic events of 6.4%. Thrombo-embolic events are considered the major complications of SAC.
Vasospasm was the main complication encountered in our study during and after endovascular intervention. Delayed cerebral ischemia is considered the worst complication after SAH occurred due to vasospasm [27].
We encountered mechanical vasospasm in three patients treated with SAC during the procedure which required nimodipine infusion and there were no related post-procedure clinical complications. SAH-related vasospasm was reported in six patients pre-intervention and caused contralateral weakness: four of the patients improved with medical treatment, however the other two patients were complicated with stroke which partially improved with physiotherapy. These findings are similar to that in the Matrix and Platinum Science trial [22] that revealed the rate of peri-procedural adverse events of patients with WNAs was similar in the SAC (6.6%) and coiling (4.5%), while at 1-year follow-up, the rate of stroke was higher in the SAC (8.8%) than in the coiling group (2.2%).
In accordance with the present results, a previous systematic review [29] has demonstrated that the overall procedure-related complication rate is 6.5%. Only two patients had intracranial hemorrhage in this study and there were six cases of groin hematomas that did not require any surgical intervention, so the rate of hemorrhagic complications was quite low. However, the risk of thrombo-embolic complications was relatively higher which was 4.9% [29]. There were no hemorrhagic complications in our study.
Several limitations should be considered in the current study. Firstly, the small size of our study sample has WNAs. Secondly, the retrospective nature of the study and the potential patient selection bias for endovascular treatment. Thirdly, the rarity of using some high-cost endovascular modalities in the treatment of WNAs, such as flow diverters.
