Surgically treated aneurysms previously coiled: lessons learned

OBJECTIVE: Intravascular coil embolization of cerebral aneurysms has proved to be a safe and effective treatment in certain patient groups; however, this treatment is relatively new, and the long-term outcomes are unknown. One of the known complications is refilling of the aneurysm dome, which is seen in follow-up studies. This patient population poses unique technical difficulties for the neurosurgeon. We present a series of 18 patients who underwent surgery for residual aneurysms after coil remobilization. METHODS: During a 5-year period, we performed surgery in 18 patients who had previously undergone coil embolization for their aneurysms. Of these aneurysms, four were in the anterior communicating artery, five were in the posterior communicating artery, three were in the internal carotid artery, three were in the posteroinferior cerebellar artery, and three were in the middle cerebral artery. One patient presented with rupture, one presented with acute IIIrd cranial nerve palsy, and the rest of the aneurysms were found on routine follow-up angiograms. Fifteen aneurysms were clipped, and in three patients, they were wrapped because the clip could not be placed adequately. RESULTS: There were no major complications in any of the patients, and all had uneventful recoveries. The presence of coils in the aneurysm dome and/or neck made clipping and exposure of the aneurysm neck difficult, resulting in incomplete neck obliteration in three patients. CONCLUSION: Operative clipping after previous coil embolization in aneurysms poses a unique problem for neurosurgeons. With the increasing use of coil embolization, this patient population will undoubtedly increase. The neurosurgeon should be aware of the difficulties and pitfalls encountered in these patients.