Incomplete surgical treatment of intracranial aneurysms and recurrent postsurgical aneurysms are associated with a risk of aneurysm rebleeding, and additional treatment is generally recommended. Surgical retreatment may carry a risk of procedural complications due to technical difficulty.

The largest study to date reported that there were 13 lethal rebleeds from the clipped saccular intracranial aneurysms out of 1440 cases at the median times of 4.9 years ¹⁾.

A successfully applied clip for a ruptured aneurysm keeps the aneurysm's neck closed, preventing rerupture throughout the patient's life. Unfortunately, rebleeding from a clipped aneurysm does occur, but the likelihood declines with time. Since relatively old people suffer from subarachnoid hemorrhage, they die from diseases other than rebleeding, such as cancer. Therefore, rebleeding from a clipped aneurysm after two decades is quite rare.

Ishida et al, report 2 cases of rerupture after an extremely long time since the initial clipping. In both cases, the old clip was removed, and the regrown gourd-shaped aneurysm was successfully obliterated. The clips in both cases were submitted to their manufacturers and inspected thoroughly. They were found to be second-generation, stainless steel clips, and were almost intact, even keeping their closing forces. In both cases, the clip existed on the surface of the newly made dome, and the previous dome completely disappeared.

They experienced 2 cases of rebleeding from the clipped aneurysm after 35 years. In one of the cases, the clip was a Yasargil second generation stainless steel clip that retained its mechanical properties and surface elemental composition in vivo for a long time. These cases should be informative as they show extremely long-term course of a clip applied for a ruptured aneurysm ²⁾.