Posterior Clinoidectomy: Dural Tailoring Technique and Clinical Application

ABSTRACT

The posterior clinoid process, a bony prominence at the superolateral aspect of the dorsum sellae, has a strategic importance in a transcavernous approach to basilar tip aneurysms. To further optimize this microsurgical technique during posterior clinoidectomy, we performed a cadaveric study of this regional anatomy, describe a technique called dural tailoring, and report initial results in the surgical treatment of upper basilar artery (BA) aneurysm. After 10 adult cadaver heads (silicone-injected) were prepared for dissection, a posterior clinoidectomy with dural tailoring was performed. The dura overlying the upper clivus was coagulated with bipolar electrocoagulation and incised. Stripping dura off the clivus and lateral reflection then exposed the ipsilateral posterior clinoid process and dorsum sellae, thus creating a dural flap. Posterior clinoidectomy with dural tailoring was then used in seven patients with upper BA aneurysms. Our stepwise modification of the posterior clinoidectomy with dural tailoring created a flap that afforded protection of the cavernous sinus and oculomotor nerve. During surgery, there were no recorded intraoperative injuries to neurovascular structures. One patient died postoperatively from morbidity related to severe-grade subarachnoid hemorrhage. Postoperative oculomotor nerve palsy occurred in 3 patients (43%). In all cases, the nerve was anatomically preserved and partial to complete recovery was recorded during the first postoperative year. This technique effectively provided exposure of retrosellar upper basilar aneurysms in seven patients (basilar tip 43% and superior cerebellar artery aneurysms 57%). Outcomes and safety are at least equivalent to or better than basilar aneurysm surgery performed without surgical adjuncts, presumably a less complex subset.

KEYWORDS

Posterior clinoid - clinoidectomy - dural tailoring - basilar artery - oculomotor nerve

REFERENCES

• 1 Yasargil M G. Microneurosurgery: Clinical Considerations, Surgery of the Intracranial Aneurysms and Results. Stuttgart; Georg Thieme 1984
• 2 Dolenc V V, Skrap M, Sustresic J, Skrbec M, Morina A. A transcavernous-transsellar approach to the basilar tip aneurysms.  Br J Neurosurg. 1987;  1 251-259
• 3 Chanda A, Nanda A. Anatomical study of the orbitozygomatic transsellar-transcavernous-transclinoidal approach to the basilar artery bifurcation.  J Neurosurg. 2002;  97 151-160
• 4 Day J D, Giannotta S L, Fukushima T. Extradural temporopolar approach to lesions of the upper basilar artery and infrachiasmatic region.  J Neurosurg. 1994;  81 230-235
• 5 Lawton M T, Daspit C P, Spetzler R F. Technical aspects and recent trends in the management of large and giant midbasilar artery aneurysms.  Neurosurgery. 1997;  41 513-521
• 6 Seoane E, Tedeschi H, de Oliveira E, Wen H T, Rhoton A L. The pretemporal transcavernous approach to the interpeduncular and prepontine cisterns: microsurgical anatomy and technique application.  Neurosurgery. 2000;  46 891-899
• 7 Yasuda A, Campero A, Martins C, Rhoton Jr A L, Oliveira E, Ribas G C. Microsurgical anatomy and approaches to the cavernous sinus.  Neurosurgery. 2005;  56 4-27 discussion 4-27
• 8 Youssef A S, Abdel Aziz K M, Kim E Y, Keller J T, Zuccarello M, van Loveren H R. The carotid-oculomotor window in exposure of upper basilar artery aneurysms: a cadaveric morphometric study.  Neurosurgery. 2004;  54 1181-1187 discussion 1187-1189
• 9 Dolenc V V. Anatomy and Surgery of the Cavernous Sinus. New York, NY; Springer-Verlag 1989: 196-219
• 10 Dolenc V V. Microsurgical Anatomy and Surgery of the Central Skull Base. New York, NY; Springer-Verlag 2003: 116-133
• 11 Aziz K M, Froelich S C, Cohen P L, Sanan A, Keller J T, van Loveren H R. The one-piece orbitozygomatic approach: the MacCarty burr hole and the inferior orbital fissure as keys to technique and application.  Acta Neurochir (Wien). 2002;  144 15-24
• 12 Youssef A S, van Loveren H R. Microvascular retractor: a new concept of retracting and repositioning cerebral blood vessels.  Neurosurgery. 2005;  57 199-202
• 13 Al-Khayat H, Al-Khayat H, White J, Manner D, Samson D. Upper basilar aneurysms: oculomotor outcomes in 163 cases.  J Neurosurg. 2005;  102 482-488
• 14 Cruciger M P, Hoyt W F, Wilson C B. Peripheral and midbrain oculomotor palsies from operations for basilar bifurcation aneurysm in a series of 31 cases.  Surg Neurol. 1981;  15 215-216
• 15 Horikoshi T, Nukui H, Yagishita T, Nishigaya K, Fukasawa I, Sasaki H. Oculomotor nerve palsy after surgery for the upper basilar artery aneurysms.  Neurosurgery. 1999;  44 705-710
• 16 Sugita K, Kobayashi S, Shintani A, Mutsuga N. Microsurgery for aneurysms of the basilar artery.  J Neurosurg. 1979;  51 615-620
• 17 Dolenc V V, Prestor B P, Sustersic J, Pregelj R. Transclinoid-Transsellar-Transcavernous Approach to Basilar Tip Aneurysms; New trends in Management of Cerebro-Vascular Malformations. New York, NY; Springer-Verlag 1994: 231-237
• 18 Figueiredo E G, Zabramaski J M, Deshmukh P, Crawford N, Preul M C, Spetzler R F. Anatomical and quantitative description of the transcavernous approach to the interpeduncular and prepontine cisterns: technical note.  J Neurosurg. 2006;  104 957-964
• 19 Kawase T, van Loveren H L, Keller J T, Tew J M. Meningeal architecture of the cavernous sinus: clinical and surgical implications.  Neurosurgery. 1996;  39 527-536