Clipping is a surgical procedure, performed by a neurosurgeon, to treat a brain aneurysm.  An incision is made in the skin over the head and through the bone to dissect within the spaces of the brain and place a clip across the aneurysm where it arises from the blood vessel. This prevents the blood flow from entering the aneurysm.

The clip works like a tiny coil-spring clothespin, in which the blades of the clip remain tightly closed until the pressure is applied to open the blades. Clips are made of titanium and remain on the artery permanently.

Animation of virtual aneurysm clipping procedure

Microvascular clipping involves cutting off the flow of blood to the aneurysm. Under anesthesia, a section of the skull is removed and the aneurysm is located. The neurosurgeon uses a microscope to isolate the blood vessel that feeds the aneurysm and places a small, metal, clothespin-like clip on the aneurysm’s neck, halting its blood supply. The clip remains in the patient and prevents the risk of future bleeding. The piece of the skull is then replaced and the scalp is closed. Clipping has been shown to be highly effective, depending on the location, shape, and size of the aneurysm. In general, aneurysms that are completely clipped surgically do not return.

Clipping may be an effective treatment for the following:

Ruptured aneurysms burst open and release blood into the space between the brain and skull, called a subarachnoid hemorrhage (SAH). The risk of repeated bleeding is 35% within the first 14 days after the first bleed. So, timing of surgery is important – usually within 72 hours of the first bleed. Vasospasm is a common complication of SAH, which must be closely managed after treatment to prevent stroke.

Unruptured aneurysms may not cause symptoms and are typically detected during routine testing. People with a family history of brain aneurysms should have a screening test (CT or MR angiogram). The risk of aneurysm rupture is about 1% per year but may be higher or lower depending on the size and location of the aneurysm. However, when rupture occurs, the risk of death is 40%, and the risk of disability is 80%.

Clipping vs. Coiling

Comparing the long-term results of coiling vs. clipping of aneurysms is an area of ongoing study.  Clipping has proven its long-term effectiveness over several decades.  In recent years, coiling has gained acceptance as an alternative to clipping for treatment of ruptured subarachnoid hemorrhage (SAH).  There have been considerable advances in open surgery techniques. Many neurosurgeons can now perform mini craniotomies, or eye brow incisions to clip an aneurysm. In select patients a small incision is made over the eyebrow. A small two inch window is then made in the bone over the eye and through this incision a small clip is placed across the opening of the aneurysm. These patients usually spend 1-2 days in the hospital after surgery and then go home. Patients are usually on light restricted activity for 1-2 months after surgery. However, it is still an invasive procedure and takes longer to recover from than a coiling procedure.

Illustration showing a side by side view of the coiling and the clipping procedure