Subarachnoid hemorrhage after aneurysm surgery.

The surgical treatment of intracranial aneurysms by clipping is recognized as effective and definitive. However some cases that suffered a new subarachnoid hemorrhage (SAH) some time after they were submitted to aneurysm clipping have raised doubts about the concept of "cure" after this treatment. Eleven patients previously submitted to aneurysm clipping who presented a new SAH were analyzed. The time elapsed from surgery to SAH varied from 3 to 10 years. After SAH four patients had a poor outcome. The new episode of SAH occurred due to intrinsic factors of the cerebral vasculature: 1. a weak point of the vessel wall near the previous aneurysm, 2. a weak point of another vessel far from the previous aneurysm, 3. a previous infundibular dilation of the posterior communicating artery; and due to technical problems: 1. aneurysm not identified during the previous treatment, 2. aneurysm deliberately left untreated, 3. persistence of the aneurysm due to inappropriate surgery, 4. persistency of part of the aneurysm neck after clipping and 5. slipping of the clip from the neck of the aneurysm. The measures to prevent new SAH after surgery start with adequate preoperative angiographic studies, a careful inspection of the position of the clip and emptying of the aneurysm. Early angiography studies may reveal a persistent neck and later ones may reveal newly developed aneurysms. In conclusion, SAH after aneurysm clipping is a late and severe phenomenon and the concept of "cure" after this surgery should be interpreted with caution.