From the Guidelines
The annual rupture risk of a 7 mm superior hypophyseal artery (SHA) aneurysm is approximately 0.5% per year, as it falls into the small-sized aneurysm category with no history of subarachnoid hemorrhage (SAH) in the anterior circulation. This risk assessment is based on the natural history data from the International Study of Unruptured Intracranial Aneurysms (ISUIA) 1, which is one of the most rigorous and largest studies of the natural history of unruptured intracranial aneurysms. The ISUIA study found that aneurysm size and location are significant predictors of rupture risk, with smaller aneurysms (<7 mm) in the anterior circulation having a lower rupture risk compared to those in the posterior circulation or posterior communicating artery.
Key factors to consider in the management of a 7 mm SHA aneurysm include:
- Aneurysm size and location: The SHA aneurysm is located in the anterior circulation, which generally carries a lower rupture risk compared to aneurysms in the posterior circulation.
- History of SAH: The absence of a history of SAH from a different aneurysm is associated with a lower rupture risk.
- Patient characteristics: Age, overall health status, and presence of risk factors such as smoking, hypertension, and family history of aneurysmal subarachnoid hemorrhage may influence the decision between observation and intervention.
- Aneurysm morphology: Irregular shape or presence of daughter sacs may increase the rupture potential.
Treatment options for a 7 mm SHA aneurysm typically include observation with regular imaging follow-up (usually annual MRA or CTA) versus interventional treatment (endovascular coiling or surgical clipping) 1. The decision between observation and intervention should be individualized based on patient-specific factors and discussion of the risks of both rupture and treatment complications.
From the Research
Annual Rupture Risk of a 7 mm Superior Hypophyseal Artery (SHA) Aneurysm
- The annual rupture risk of a 7 mm SHA aneurysm is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, a study published in 2025 3 mentions that early intervention is crucial to prevent rupture, especially for larger aneurysms (> 7 mm), but does not provide a specific annual rupture risk.
- Another study published in 2023 5 discusses the correlation factors for SHA aneurysm rupture, including the presence of type IA or IB cavernous internal carotid artery (cICA), but does not provide a specific annual rupture risk for a 7 mm aneurysm.
- The provided studies focus on the treatment and management of SHA aneurysms, including endovascular embolization 2, microsurgical vs. endovascular treatment 3, surgical considerations 4, and long-term outcomes of coil embolization 5, but do not provide a clear answer to the question of annual rupture risk.
Factors Influencing Rupture Risk
- The presence of type IA or IB cavernous internal carotid artery (cICA) is strongly correlated with SHA aneurysm rupture 5.
- Aneurysm size, with larger aneurysms (> 7 mm) being at higher risk of rupture 3.
- The study published in 2025 3 mentions that most aneurysms were smaller than 7 mm, but does not provide a specific annual rupture risk for a 7 mm aneurysm.
Treatment and Management
- Endovascular embolization is a viable treatment option for SHA aneurysms 2.
- Microsurgical clipping is also a viable treatment option, especially for smaller lesions 3.
- Coil embolization is an effective treatment modality for SHA aneurysms, leading to low recurrence and complication rates, especially with stent use 5.