How are unruptured aneurysms treated by surgery?

Unruptured aneurysms can be treated surgically through various methods, depending on the specific characteristics and location of the aneurysm. Here are the main surgical approaches:

1. Clipping: A clip is placed across the neck of the aneurysm, blocking the blood flow into the aneurysm while preserving blood flow to the surrounding healthy arteries. This technique is commonly used for aneurysms located in easily accessible areas, such as the anterior communicating artery (AComA).

2. Surgical Trapping: This involves ligating (tying off) both ends of the aneurysm, effectively isolating it from the main blood flow. Surgical trapping is often performed when the aneurysm is located at the junction of two arteries, making clipping difficult or risky.

3. Endovascular Coiling: Endovascular coiling is a minimally invasive procedure that can be used to treat certain types of unruptured aneurysms. A catheter is inserted into the femoral artery and guided to the aneurysm. Platinum coils are then released into the aneurysm, causing it to clot and thrombose. This technique is especially useful for aneurysms located in more challenging areas, such as the basilar artery or posterior circulation.

4. Flow Diversion: Flow diversion involves placing a stent-like device across the neck of the aneurysm, redirecting blood flow away from the aneurysm. The reduced blood flow promotes thrombosis within the aneurysm and encourages healing. Flow diversion is particularly effective for aneurysms that have a wide neck or are located in complex anatomical areas.

5. Bypass Surgery: In rare cases, unruptured aneurysms may require bypass surgery. During this procedure, a new blood vessel is created to bypass the affected artery, restoring blood flow to the brain while avoiding the aneurysm. Bypass surgery is typically used when the aneurysm is very large or involves multiple arteries.

The decision regarding the most appropriate surgical approach for an unruptured aneurysm is made by a neurosurgeon based on the size, location, and overall condition of the patient, as well as their expertise and experience with different techniques.