Guideline sources The following summarized guidelines for the evaluation and management of unRuptured intracranial aneurysm (UIA) are prepared by our editorial team based on guidelines from the European Stroke Organisation (ESO 2022; 2013) and the American Heart Association (AHA/ASA 2015). 1 2 3 Calculator PHASES score for intracranial an Guidelines https://web.pathway.md/diseases/rec01Uw9e21y4uia6 1/6 6/29/23, 3:47 AM Unruptured intracranial aneurysm Pathway 1. Screening and diagnosis Indications for screening: As per AHA 2015 guidelines, offer aneurysmal screening by computed tomographic angiography or MRA in patients with 2 family members with intracranial aneurysms or subarachnoid hemorrhage. View history of hypertension, smoking, and female sex as risk factors predicting a particularly high risk of aneurysm occurrence in such families. B Show 2 more As per ESO 2013 guidelines: Avoid obtaining screening in the presence of only one affected first-degree relative. Consider obtaining screening in the presence of 2 affected first-degree relatives, as the lifetime risk of subarachnoid hemorrhage in the other relatives is considerable. C 2. Classification and risk stratification Risk factors: As per AHA 2015 guidelines: Recognize that cigarette smoking increases the risk of unruptured intracranial aneurysms formations, and hypertension is a risk factor for growth and rupture of intracranial aneurysms. B Consider viewing prior history of aneurysmal subarachnoid hemorrhage as an independent risk factor for future hemorrhage secondary to a different small unruptured aneurysm. C As per ESO 2013 guidelines, recognize that: hypertension is an important risk factor for subarachnoid hemorrhage and possibly for aneurysm formation and fatal aneurysm rupture cigarette smoking is the most important modifiable risk factor for aneurysm formation, growth and rupture alcohol abuse and particularly sudden intake of high quantities is a risk factor for aneurysm rupture. E 3. Diagnostic investigations Diagnostic imaging: As per AHA 2015 guidelines: Consider obtaining computed tomographic angiography and MRA for detection of unruptured intracranial aneurysms. B Consider obtaining digital subtraction angiography over noninvasive imaging for identification and evaluation of cerebral aneurysms, if surgical or endovascular treatment is being considered. C 4. Medical management Antihypertensive therapy: https://web.pathway.md/diseases/rec01Uw9e21y4uia6 2/6 6/29/23, 3:47 AM Unruptured intracranial aneurysm Pathway As per ESO 2022 guidelines, manage hypertension in adult patients with unruptured intracranial aneurysm and increased BP. B As per AHA 2015 guidelines, monitor BP and initiate treatment for hypertension in patients with unruptured intracranial aneurysms to prevent growth and rupture of aneurysms. B Antiplatelet therapy: avoid using aspirin for decreasing the risk of aneurysm growth or rupture in adult patients with unruptured intracranial aneurysms. D Statin therapy: avoid using statins for decreasing the risk of aneurysm growth or rupture in adult patients with unruptured intracranial aneurysms. D 5. Nonpharmacologic interventions Smoking cessation: As per ESO 2022 guidelines, advise smoking cessation in smoker patients with unruptured intracranial aneurysm. B As per AHA 2015 guidelines, counsel patients with unruptured intracranial aneurysms regarding the importance of smoking cessation. B As per ESO 2013 guidelines, advise smoking cessation for the prevention of aneurysm formation, growth and rupture. E Alcohol intake: advise limiting alcohol intake, particularly avoiding sudden intake of high quantities, for the prevention of aneurysm rupture. E 6. Therapeutic procedures Endovascular coiling: As per ESO 2022 guidelines, consider performing placement of flow-diverting stents as a treatment option in adult patients with unruptured intracranial aneurysm only if no other endovascular or microsurgical options to occlude the aneurysm (complete occlusion or neck remnant only) at a risk lower than the expected 5-year risk of rupture are available and if the risk of rupture outweighs the risk of treatment with flow-diverting stents. C As per AHA 2015 guidelines, recognize that endovascular coiling is associated with a reduction in procedural morbidity and mortality over surgical clipping in selected patients but has an overall higher risk of recurrence. B Show 4 more Updated evidence: GREAT In adult patients with untreated small-to-medium-sized intracranial aneurysms, hydrogel coil was superior to bare platinum coil with respect to the percentage of patients with unfavorable angiographic and clinical events. Christian A Taschner et al. Stroke. 2018 Mar. https://web.pathway.md/diseases/rec01Uw9e21y4uia6 3/6 6/29/23, 3:47 AM Unruptured intracranial aneurysm Pathway 7. Perioperative care Post-intervention imaging: obtain imaging after surgical intervention to document aneurysm obliteration given the differential risk of growth and hemorrhage for completely versus incompletely obliterated aneurysms. B 8. Surgical interventions Indications for aneurysm repair: As per ESO 2022 guidelines: Consider performing preventive aneurysm repair in adult patients with an estimated 5-year risk of aneurysm rupture higher than the risk of the preventive treatment modality. C Consider performing preventive aneurysm repair in adult patients with a unruptured intracranial aneurysm showing growth on follow-up imaging, weighing the risk of rupture against the risk of treatment complications. C As per AHA 2015 guidelines, consider offering treatment of unruptured intracranial aneurysms in patients with a family history of intracranial aneurysms even in aneurysms at smaller sizes than spontaneously occurring intracranial aneurysms. C Show 4 more Choice of repair technique: As per ESO 2022 guidelines: Insufficient evidence to recommend in preference of a specific treatment modality (either endovascular or microsurgical) in adult patients with unruptured intracranial aneurysm. I Consider taking into account the following factors impacting the risk/benefit profile of the procedures when deciding between endovascular and microsurgical treatment in adult patients with unruptured intracranial aneurysm: increasing age (increased risk of complications for microsurgical treatment) female gender (slightly increased risk for endovascular therapy, strongly decreased risk for microsurgical treatment) indication for anticoagulation (strongly increased for microsurgical treatment) a broad neck of the aneurysm (increased risk for endovascular treatment), aneurysm calcification (increased risk for microsurgical treatment) location on the posterior circulation (slightly increased risk for endovascular therapy and strongly increased risk for microsurgical treatment). C As per AHA 2015 guidelines: Take into account patient age, aneurysm location and size when considering surgical clipping as the mode of treatment for unruptured intracranial aneurysms. B Consider using specialized intraoperative tools and techniques for avoiding vessel compromise or residual aneurysms to reduce the adverse outcomes seen with operative management of unruptured intracranial aneurysms. C 9. Patient education https://web.pathway.md/diseases/rec01Uw9e21y4uia6 4/6 6/29/23, 3:47 AM Unruptured intracranial aneurysm Pathway General counseling: inform patients with unruptured intracranial aneurysms considered for treatment about the risks and benefits of both endovascular and microsurgical aneurysm clipping. B 10. Follow-up and surveillance Follow-up imaging, managed conservatively: As per ESO 2022 guidelines: Obtain radiological monitoring to detect future unruptured intracranial aneurysm growth or morphological change in adult patients with unruptured intracranial aneurysms if the risk of treatment complications is higher than the 5-year risk of rupture and if treatment remains an option. B Consider performing preventive aneurysm repair in adult patients with a unruptured intracranial aneurysm showing growth on follow-up imaging, weighing the risk of rupture against the risk of treatment complications. C As per ASA/AHA 2015 guidelines, consider obtaining intermittent imaging to follow patients with unruptured intracranial aneurysms managed conservatively, as aneurysmal growth may increase the risk of rupture. B Show 3 more Follow-up imaging, managed invasively: As per ESO 2022 guidelines: Consider obtaining initial radiological follow-up 3-12 months after unruptured intracranial aneurysm repair to detect potential unruptured intracranial aneurysm remnants or recurrence in adult patients if aneurysm retreatment remains an option. C Discuss the pros and cons of retreatment in the short-term versus a future radiological follow-up in adult patients with a treated unruptured intracranial aneurysm and recurrence of the aneurysm, agreed upon in a shared decision-making process between the physician and patient based on the recommendation by the multidisciplinary team and patient-related psychosociological factors. B As per ASA/AHA 2015 guidelines, obtain follow-up evaluation in patients with coiled aneurysms, especially with wider neck or dome diameters or having residual filling. B Show 4 more 11. Quality improvement Hospital requirements: Treat patients with unrupted intracranial aneurysm, either with endovascular or surgical approach, at higher-volume centers. B Perform surgical treatment of unruptured intracranial aneurysms at higher-volume centers, such as performing > 20 cases annually). B Clinical findings https://web.pathway.md/diseases/rec01Uw9e21y4uia6 5/6 6/29/23, 3:47 AM Unruptured intracranial aneurysm Pathway Symptoms Past medical history Dizziness Aortic aneurysm Eye pain Cerebral AVMs Facial pain Coarctation of aorta Headache Hypertension Social history Neurological exam Cigarette smoking Cranial nerve palsy Mydriasis Ocular exam Amaurosis fugax References 1. B Gregory Thompson, Robert D Brown Jr, Sepideh Amin-Hanjani et al. Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2015 Aug;46 8 2368 400. Open 2. Nima Etminan, Diana Aguiar de Sousa, Cindy Tiseo et al. European Stroke Organisation ESO guidelines on management of unruptured intracranial aneurysms. Eur Stroke J. 2022 Sep;7 3 V. Open 3. Thorsten Steiner, Seppo Juvela, Andreas Unterberg et al. European Stroke Organization guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage. Cerebrovasc Dis. 2013;35 2 93 112. Open https://web.pathway.md/diseases/rec01Uw9e21y4uia6 6/6