Selective extradural anterior clinoidectomy for supra- and parasellar processes (original) (raw)
Related papers
Operative Neurosurgery, 2015
BACKGROUND: Drilling of the anterior clinoid process (ACP) is an integral component of surgical approaches for central and paracentral skull base lesions. The technique to drill ACP has evolved from pure intradural to extradural and combined techniques. OBJECTIVE: To describe the computerized morphometric evaluation of exposure of optic nerve and internal carotid artery with proposed tailored intradural (IDAC) and complete extradural (EDAC) anterior clinoidectomy. METHODS: We describe a morphometric subdivision of ACP into 4 quadrangles and 1 triangle on the basis of fixed bony landmarks. Computerized volumetric analysis with 3dimensional laser scanning of dry-drilled bones for respective tailored IDAC and EDAC was performed. Both approaches were compared for the area and length of the optic nerve and internal carotid artery. Five cadaver heads were dissected on alternate sides with intradural and extradural techniques to evaluate exposure, surgical freedom, and angulation of approach. RESULTS: Complete anterior clinoidectomy provides a 2.5-times larger area and 2.7times larger volume of ACP. Complete clinoidectomy deroofed the optic nerve to an equal extent as by proposed the partial tailored clinoidectomy approach. Tailored IDAC exposes only the distal dural ring, whereas complete EDAC exposes both the proximal and distal dural rings with complete exposure of the carotid cave. CONCLUSION: Quantitative comparative evaluation provides details of exposure and surgical ease with both techniques. We promote hybrid/EDAC technique for vascular pathologies because of better anatomic orientation. Extradural clinoidectomy is the preferred technique for midline cranial neoplasia. An awareness of different variations of clinoidectomy can prevent dependency on any particular approach and facilitate flexibility.
Extradural anterior clinoidectomy: Technical nuances from a learner′s perspective
Asian Journal of Neurosurgery, 2014
been debated upon. Extradural anterior clinoidectomy is often perceived as difficult and risky due to the constricted working space and the vulnerability of critical anatomical structures encountered, which includes the clinoidal carotid segment, oculomotor nerve and the optic nerve. However, with proper extradural exposure of the ACP and accurate knowledge of the anatomical relationships in this region, extradural anterior clinoidectomy can be safely accomplished. Illustrating through cadaveric prosection, we intend to describe in this paper the proper technique for extradural clinoidectomy, emphasizing the key steps for optimum exposure and safe removal of the anterior clinoid.
Anterior clinoidectomy using an extradural and intradural 2-step hybrid technique
Journal of neurosurgery, 2018
Anterior clinoidectomy is a difficult yet essential technique in skull base surgery. Two main techniques (extradural and intradural) with multiple modifications have been proposed to increase efficiency and avoid complications. In this study, the authors sought to develop a hybrid technique based on localization of the optic strut (OS) to combine the advantages and avoid the disadvantages of both techniques. Ten cadaveric specimens were prepared for surgical simulation. After a standard pterional craniotomy, the anterior clinoid process (ACP) was resected in 2 steps. The segment anterior to the OS was resected extradurally, while the segment posterior to the OS was resected intradurally. The proposed technique was performed in 6 clinical cases to evaluate its safety and efficiency. Anterior clinoidectomy was successfully performed in all cadaveric specimens and all 6 patients by using the proposed technique. The extradural phase enabled early decompression of the optic nerve while a...
Extradural resection of the anterior clinoid process: How I do it
Neurochirurgie, 2017
Background.-The anterior clinoid process shares a close relationship with the optic canal, the internal carotid artery, the superior orbital fissure and the cavernous sinus. These structures may be involved in diseases whose surgical exposure requires prior clinoid process resection. Method.-Based on operative cases we describe the different steps of this surgical technique and illustrate our surgical procedure with a video. Dividing the orbito-temporal periosteal fold is a key-step in order to optimize the elevation of the periosteal dural layer at the level of the superior orbital fissure to expose the contours of the anterior clinoid process. The clinoid tip is removed after "debulking" the bony content inside the anterior clinoid process in order to leave only a thin shell of bony contour. The bony shell is then detached from the dura, twisted and pulled out. The indications and limitations of the technique are presented. Conclusion.-The extradural approach of the anterior clinoid process totally provides a full resection of the anterior clinoid process and safety for the paraclinoid space structures. Meticulous stepwise bony resection and optimized dura opening contribute to reduce the risk inherent to this technique.
Neurosurgical Review, 2018
To evaluate the safety and efficacy of intradural Blimited drill^technique (ILDT) of anterior clinoidectomy (AC) and optic canal unroofing (OCU) for microneurosurgical management of ophthalmic segment and posterior communicating artery (PCOM) aneurysms. All the patients with ophthalmic segment and PCOM aneurysms who underwent AC and OCU by ILDT for microneurosurgical management of ophthalmic segment and PCOM aneurysms during 4-year period (2013-2016) at our Institute were included in this study. In ILDT of AC and OCU, the use of power drill is restricted to AC only and OCU is done exclusively with 1-mm Kerrison punch. AC and OCU by ILDT were done in 24 patients with 29 ophthalmic segment and 7 PCOM aneurysms. AC and OCU by ILDT helped in mobilization of optic nerve/internal carotid artery (ICA) and provided excellent exposure for all these aneurysms. There was no injury to ICA or optic nerve during drilling. AC and OCU facilitated clip ligation of 34 of these aneurysms. Remaining 2 aneurysms were considered not suitable for clipping. Check angiogram done for 33 aneurysms revealed complete obliteration of 26 aneurysms, very small residual neck in 5 aneurysms, and small residual aneurysm in 2 aneurysms. Deterioration in vision was noted in 1 patient (4.1%). In 6 patients with preoperative visual deficits, significant improvement in vision was noted in 4 patients (4/6-66.6%) after surgery. Good outcome (MRS < 2) was noted in 91.6% (22/ 24) of these patients. ILDT is a safe and effective technique of AC and OCU which provide good exposure for ophthalmic segment and PCOM aneurysms.
Neurosurgery, 2015
Drilling of the anterior clinoid process (ACP) is an integral component of surgical approaches for central and paracentral skull base lesions. The technique to drill ACP has evolved from pure intradural to extradural and combined techniques. To describe the computerized morphometric evaluation of exposure of optic nerve and internal carotid artery with proposed tailored intradural (IDAC) and complete extradural (EDAC) anterior clinoidectomy. We describe a morphometric subdivision of ACP into 4 quadrangles and 1 triangle on the basis of fixed bony landmarks. Computerized volumetric analysis with 3-dimensional laser scanning of dry-drilled bones for respective tailored IDAC and EDAC was performed. Both approaches were compared for the area and length of the optic nerve and internal carotid artery. Five cadaver heads were dissected on alternate sides with intradural and extradural techniques to evaluate exposure, surgical freedom, and angulation of approach. Complete anterior clinoidec...
Extradural anterior clinoidectomy in surgical management of clinoidal meningiomas
The Egyptian Journal of Neurology, Psychiatry and Neurosurgery, 2021
Background Despite the recent advances in skull base surgery, microsurgical techniques, and neuroimaging, yet surgical resection of clinoidal meningiomas is still a major challenge. In this study, we present our institution experience in the surgical treatment of anterior clinoidal meningiomas highlighting the role of extradural anterior clinoidectomy in improving the visual outcome and the extent of tumor resection. This is a prospective observational study conducted on 33 consecutive patients with clinoidal meningiomas. The surgical approach utilized consisted of extradural anterior clinoidectomy, optic canal deroofing with falciform ligament opening in all patients. The primary outcome assessment was visual improvement and secondary outcomes were extent of tumor resection, recurrence, and postoperative complications. Results The study included 5 males and 28 females with mean age 49.48 ± 11.41 years. Preoperative visual deficit was present in 30 (90.9%) patients. Optic canal invo...
Fronto-temporo-orbitozygomatic craniotomy and "half-and-half" approach for basilar apex aneurysms
Neurology India, 2009
Background: Basilar apex aneurysms (BAA) are located in interpeduncular cistern surrounded by eloquent neurovascular structures. Surgical access is difficult due to narrow surgical corridors and requires traversing through a depth of 6-8 cm of subarachnoid space. Aim: Surgical management of BAAs clipped using frontotemporal craniotomy, orbitozygomatic osteotomy with combined subtemporal and transylvian (half and half) approach is discussed. Setting and Design: Tertiary care referral institute; prospective study. Materials and Methods: Five patients with BAA rupture causing subarachnoid hemorrhage presented in modified Hunt and Hess (Hand H) grades II (n 5 1), III (n 5 1) and IV (n 5 3), respectively. In 4 patients, the aneurysms were 0.8-1.2 cm in diameter, situated 7 mm-1 cm above dorsum sellae. Two of them had posteriorly projecting aneurysms. One patient had a giant, high BAA with a left parietooccipital arteriovenous malformation. Vasospasm of posterior cerebral/proximal basilar artery was seen in 2 patients. In one patient, internal carotid artery was mobilized by intradural anterior clinoid drilling with carotid collar division. Triple-H therapy was administered following surgery. Results: There was no intraoperative rupture or temporary clipping. Follow up angiography showed complete aneurysmal obliteration with preservation of posterior cerebral and superior cerebellar arteries. Follow up (mean: 8.7 6 3.5 months) H and H grades were II (n 5 2) and III (n 5 3), respectively. The morbidity include caudate and thalamic region infarct, transient III rd nerve palsy and cerebrospinal fluid otorrhoea (n 5 1, respectively). Conclusions: This simple approach provides a wide surgical corridor from 5 mm below to greater than 1 cm above dorsum sellae with adequate proximal control of basilar artery. It is an option to endovascular embolization especially with large and giant, or wide-necked BAA, vertebrobasilar tortuosity, coil compaction or postcoiling re-rupture and an associated large haematoma.
Surgical clipping is still a good choice for the treatment of paraclinoid aneurysms
Arquivos de Neuro-Psiquiatria, 2016
Paraclinoid aneurysms are lesions located adjacent to the clinoid and ophthalmic segments of the internal carotid artery. In recent years, flow diverter stents have been introduced as a better endovascular technique for treatment of these aneurysms. Method From 2009 to 2014, a total of 43 paraclinoid aneurysms in 43 patients were surgically clipped. We retrospectively reviewed the records of these patients to analyze clinical outcomes. Results Twenty-six aneurysms (60.5%) were ophthalmic artery aneurysms, while 17 were superior hypophyseal artery aneurysms (39.5%). The extradural approach to the clinoid process was used to clip these aneurysms. One hundred percent of aneurysms were clipped (complete exclusion in 100% on follow-up angiography). The length of follow-up ranged from 1 to 60 months (mean, 29.82 months). Conclusion Surgical clipping continues to be a good option for the treatment of paraclinoid aneurysms.