Results of microsurgical treatment of paraclinoid carotid aneurysms

The term "paraclinoid aneurysms", has been used for aneurysms of the internal carotid artery (ICA) between the cavernous sinus and the posterior communicating artery. Due to their complex anatomical relationship at the skull base and because they are frequently large/giant, their surgical treatment remains a challenge. Ninety-five patients harboring 106 paraclinoid aneurysms underwent surgery (1990-2010). Age, 11-72 years old. Sex, 74:21 female/male. Follow-up; 1-192 months (mean = 51.7 months). Eighty-six patients had single and 9 had multiple paraclinoid aneurysms. Sixty-six were ophthalmic, 14 were in the ICA superior wall, 13 in the inferior, 10 in the medial, and 3 in the ICA lateral wall. Eleven were giant, 29 were large, and 66 were small. Sixty-three patients had ruptured and 32 had unruptured aneurysms. Two patients with bilateral aneurysms had bilateral approaches, totaling 97 procedures. A total of 98.2 % of aneurysms were clipped (complete exclusion in 93.8 %). ICA occlusion occurred in 10 (5.6 %). There was no patient rebleeding during the follow-up period. A good outcome was achieved in 76.8 %, with better results for unruptured aneurysms, worse results for patients with vasospasm, and with no difference according to size. Thirty-six (37.9 %) patients had transient/permanent postoperative neurological deficits (25.4 % ruptured vs. 62.5 % unruptured aneurysms). The most frequent deficits were visual impairment and third cranial nerve palsies. Operative mortality was 11.6 %, all in patients presenting with ruptured aneurysms. Despite relatively high morbidity/mortality, especially for patients with ruptured aneurysms, microsurgical treatment of paraclinoid aneurysm has high efficacy, with better outcome for unruptured aneurysms and worse outcome for patients with vasospasm.