Subset Of Aneurysms Research Articles

Anterior perforated substance region aneurysms: review of a series treated with microsurgical technique.

Aneurysms arising from the distal carotid, proximal A1, and proximal M1 that project posteriorly and superiorly toward the anterior perforated substance (APS) are rare. Their open surgical treatment is particularly difficult due to poorly visualized origin of the aneurysm and the abundance of surrounding perforators. We sought to analyze the anatomical and clinical characteristics of APS aneurysms and discuss surgical nuances that can optimize visualization, complete neck clip obliteration, and preservation of adjacent perforators. Thirty-two patients with 36 APS aneurysms were surgically treated between November 2000 and September 2017. Patients were prospectively enrolled in a cerebral aneurysm database and their clinical, imaging, and surgical records were retrospectively reviewed. Twenty-seven aneurysms originated from the distal ICA, 7 from the proximal A1, and 2 from the proximal M1; 15 patients presented with subarachnoid hemorrhage. Careful intraoperative dissection revealed 4 aneurysms originating at the takeoff of a perforator; another 25 had at least 1 adherent perforator. All aneurysms were clipped except for one that was trapped. Postoperatively, 3 patients had radiographic infarctions in perforator territory with only 1 developing delayed clinical hemiparesis. Good outcome (modified Rankin Scale, 0-2) was achieved in 28 patients (88%). APS aneurysms present a challenging subset of aneurysms due to their complex anatomical relationship with surrounding perforators. These should be identified on preoperative imaging based on location and projection. Successful microsurgical clipping relies on optimization of the surgical view, meticulous clip reconstruction, preservation of all perforators, and electrophysiological monitoring to minimize ischemic complication.

Pipeline embolization device diameter is an important factor determining the efficacy of flow diversion treatment of small intracranial saccular aneurysms

ObjectiveFlow diversion using the Pipeline embolization device (PED) has become a widely used treatment method for intracranial aneurysms. However, a subset of aneurysms will fail to occlude following treatment and...

Effect of aneurysm morphologic parameters on occlusion rates following pipeline embolization

ObjectiveTreatment failures with the use of Pipeline Embolization Device (PED) continue to be observed in up to 18% of patients in large case series. Adjunctive coiling and layering of multiple devices have been shown to improve occlusion rates; however, the optimal treatment strategy with the use of PED has not been established. The purpose of this study is to identify morphological characteristics predictive of treatment failure after PED. Patient and methodsA case control design was used to evaluate the association of aneurysm morphologic parameters with failure after PED placement. Retrospective analysis of patients undergoing PED for elective aneurysm treatment between 2014 and 2017 was performed. Patients who underwent PED placement with at least 12 months follow-up using conventional cerebral angiography were included for further review. Results84 patients met inclusion criteria for further analysis. ten patients (11.9%) experienced treatment failure defined by retained flow within the aneurysm and of those eight patients (9.5%) required additional retreatment. On multivariate analysis decreasing aspect ratio and increasing neck width were significant parameters that predicted treatment failure. ConclusionAneurysms with small aspect ratio and large neck width may be more likely to experience treatment failure after PED embolization. This subset of aneurysms may therefore benefit from adjunctive coiling to improve occlusion rates. Future prospective studies are needed to validate these findings.

Endovascular reconstruction of aneurysms with a complex geometry.

Conventional endovascular coiling remains the mainstay of treatment for most aneurysms; however, it may not be suitable for aneurysms with a complex geometry and there remains the risk of recanalization. Aneurysms with an unfavorable morphology are difficult to treat through both endovascular and surgical means. Progress in endovascular technology has allowed for the emergence of newer strategies to treat aneurysms with a complex geometry. Better packing density in wide-necked and large aneurysms can be achieved through the balloon remodeling technique. Similarly, a self-expanding stent cannot only act as a scaffold that helps to retain coils but also aids in diverting the blood flow away from the aneurysm sac. Lately, focus has shifted from endosaccular occlusion to endoluminal reconstruction; flow diverters are being increasingly used to treat aneurysms with an unfavorable geometry. However, there is no clear consensus on the best endovascular management strategy in certain subset of aneurysms - large and giant internal carotid aneurysms, blister aneurysms, and fusiform/dissecting aneurysms of the vertebrobasilar artery. We present a review of literature and discuss the current evidence for the various endovascular strategies to treat complex aneurysms.

Safety, efficacy, and cost of surgery for patients with unruptured aneurysms deemed unsuitable for endovascular therapy.

Open surgery is a frequent option given to patients with unruptured intracranial aneurysms (UIAs) unsuitable for endovascular repair. Since the risk of rupture of UIAs is generally low, we determined whether the risks and costs of surgery in this patient subset are warranted. The safety, efficacy, and costs of minimally invasive surgery by minicraniotomy were evaluated in 102 consecutive patients with anterior circulation UIAs deemed unsuitable for endovascular repair by an interdisciplinary conference of surgeons and neurointerventionalists. Data from 107 UIA patients treated by endovascular means in the same period were used as the standard. Surgical patients comprised a different subset of aneurysms, with more MCA and fewer paraophthalmic aneurysms (54 vs. 6, p < 0.0001 and 4 vs. 60, p < 0.0001, for minicraniotomy and endovascular, respectively). However, surgery incurred shorter anesthesia time (197.7 vs. 149.3 min, p < 0.0001), higher rates of complete aneurysm obliteration (94.57 vs. 66.67 %, p < 0.0001), and lower overall hospital costs ($8,287 CAD vs. $17,732 CAD, p < 0.0001) than the endovascular cohort. There were no treatment-related surgical deaths, but one patient had an mRS of 3 after 6 months due to temporal lobe epilepsy and memory problems. This compared favorably with the endovascular cohort in which two patients died due to treatment (mRS = 6) and one suffered a severe stroke (mRS = 5 at 6 months). For patients counseled to undergo treatment but have UIAs unsuitable for endovascular repair, surgery is safe, effective, and cost-efficient.

Clinical, radiological, and flow-related risk factors for growth of untreated, unruptured intracranial aneurysms.

Unruptured intracranial aneurysms are frequently followed to monitor aneurysm growth. We studied the yield of follow-up imaging and analyzed risk factors for aneurysm growth. We included patients with untreated, unruptured intracranial aneurysms and ≥6 months of follow-up imaging from 2 large prospectively collected databases. We assessed the proportion of patients with aneurysm growth and performed univariable and multivariable Cox regression analyses to calculate hazard ratios with corresponding 95% confidence intervals (CI) for clinical and radiological risk factors for aneurysm growth. We repeated these analyses for the subset of small (<7 mm) aneurysms. Fifty-seven (12%) of 468 aneurysms in 363 patients grew during a median follow-up of 2.1 years (total follow-up, 1372 patient-years). In multivariable analysis, hazard ratios for aneurysm growth were as follows: 1.1 (95% CI, 1.0-1.2) per each additional mm of initial aneurysm size; 2.7 (95% CI, 1.2-6.4) for dome > neck ratio; 2.1 (95% CI, 0.9-4.9) for location in the posterior circulation; and 2.0 (95% CI, 0.8-4.8) for multilobarity. In the subset of aneurysms <7 mm, 37 of 403 (9%) enlarged. In multivariable analysis, hazard ratios for aneurysm growth were 1.1 (95% CI, 0.8-1.5) per each additional mm of initial aneurysm size, 2.2 (95% CI, 1.0-4.8) for smoking, 2.9 (95% CI, 1.0-8.5) for multilobarity, 2.4 (95% CI, 1.0-5.8) for dome/neck ratio, and 2.0 (95% CI, 0.6-7.0) for location in the posterior circulation. Initial aneurysm size, dome/neck ratio, and multilobarity are risk factors for aneurysm growth. Cessation of smoking is pivotal because smoking is a modifiable risk factor for growth of small aneurysms.

Application of endovascular coiling and subsequent Onyx 34 embolization in anterior communicating artery aneurysms with adjacent hematoma

ObjectiveSmall anterior communicating artery aneurysms with recurrent bleeding and adjacent hematoma may have a high risk of post-operative rebleeding. This clinical study summarizes our preliminary experience with this subset of aneurysms, which were treated with endovascular coiling and subsequent Onyx 34 embolization. MethodsWe retrospectively reviewed the data of 9 patients suffering from small anterior communicating artery aneurysms treated with the combination of coils and Onyx. The clinical characteristics, angiographic outcomes, and follow-up results are reviewed. ResultsEndovascular coiling and Onyx embolization were successfully accomplished in all 9 cases. The Raymond scale ratings of the treatments are all class I with the parent arteries kept patent. One patient died of severe brain edema on the 5th post-operative day. The modified Rankin scale (mRS) score for the other 8 patients at follow-ups (6m to 26m, 15.8m on average) was 0 in 5 cases, 1 in 2 cases, and 3 in 1 case. Seven of 8 patients (87.5%) underwent angiographic follow-up that demonstrated persistent durable occlusion with no recanalization. ConclusionsEndovascular coiling and subsequent Onyx 34 embolization may be effective in treating anterior communicating artery aneurysms with adjacent hematoma. Further studies with larger sample size and adequate follow-up are required to verify its safety and efficacy as well as to evaluate the long-term outcome.

False-negative indocyanine green videoangiography among complex unruptured middle cerebral artery aneurysms: The importance of further aneurysm inspection

Successful surgical treatment of cerebral aneurysms requires complete occlusion of the aneurysm lumen while maintaining patency of the adjacent branching and perforating arteries. Intraoperative flow assessment allows aneurysm clip repositioning in the event these requirements are not met, avoiding the risk of postoperative rehemorrhage or infarction. A number of modalities have been proposed for primarily intraoperative qualitative blood flow assessment, including microdoppler ultrasonography, intraoperative digital subtraction angiography (DSA), and more recently noninvasive fluorescent angiography including indocyanine green (ICG) fluorescent imaging. Puncture of the aneurysm dome to exclude aneurysm sac filling may also assess the efficacy of clip placement. Although a high concordance between ICG and DSA has been reported, there remains an important subset of aneurysms for which negative ICG study may erroneously suggest aneurysm occlusion. A high-risk situation for such a false-negative study is an atherosclerotic middle cerebral artery (MCA) aneurysm in which vessel wall plaque interferes with the ICG signal. Furthermore, a decreased flow within the aneurysm may not allow enough emission light for detection under the current technology. In this report, we describe our experience with cases of MCA aneurysms with false-negative ICG-VA studies requiring clip adjustment for optimal surgical treatment and discuss two illustrative cases of MCA aneurysms with intraoperative fluorescence studies that were falsely negative, requiring puncture of the aneurysm to correctly identify incomplete aneurysm occlusion.

Surgical strategies for aneurysms deemed unclippable and uncoilable

Although most cerebral aneurysms can nowadays be successfully treated either by standard clipping or sole coiling, a subset of aneurysms may not be amenable to standard clipping or coiling and require alternative treatment options. Surgical options, other than clipping and/or endovascular options other than sole coiling, may be the optimal treatment plan for some complex aneurysms. Surgical strategies for such complex aneurysms include parent artery occlusion, revascularization procedures and flow redirection. In this article, we review which factors are predictive of failure of conventional aneurysm treatment options; summarize key information needed to orient treatment decision; and discuss surgical options for unclippable and uncoilable aneurysms.

Surgical management of intracranial aneurysms previously treated with endovascular therapy

Endovascular treatment with coils of cerebral aneurysm is being increasingly used for definitive treatment. An increasing number of patients are coming for surgical intervention either for recurrences, incomplete coil embolization or its complications. Our objective was to assess the surgical management in such patients. This was a retrospective analysis of the patients who were initially treated with endovascular embolization and later managed surgically with clipping either for unsuccessful coiling, recurrence of aneurysm or post-procedural complication, between 2003 and 2007. Anatomical results were excellent in all five patients, and all the aneurysms were totally excluded from the circulation. All patients had good recovery. None of the patients suffered any major intraoperative or postoperative complication. Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy is an emerging challenge, but with proper patient selection and careful planning, this subset of aneurysms can be managed with good results.