Intradural Anterior Clinoidectomy Research Articles

Commentary: Microsurgical Clipping of a Recurrent Posterior Communicating Artery Aneurysm With Intradural Anterior Clinoidectomy: 2-Dimensional Operative Video.

Bathini, Abhijith MD*; Olson, Vita BS*; Batjer, H. Hunt MD*; Bendok, Bernard R. MD, MSCI*,‡,§,‖,¶ Author Information

Modified intradural anterior clinoidectomy to protect the paraclinoid neurovascular structures: A technical note

ObjectiveAnterior clinoidectomy is effective in creating an adequate working field during surgery for paraclinoid lesions. However, intradural anterior clinoidectomy (iAC) is associated with intraoperative injury to the paraclinoid neurovasular structures because they are exposed in the surgical field. Here we introduce our modified technique in removing the anterior clinoid process (ACP) to compensate the drawbacks of iAC. MethodsThis technical case report is presented by demonstration of cadaver dissection and surgical video. ResultsCadaver dissection study demonstrates the step-by-step procedure. Our technique primarily aims at sectioning of the dura adjacent to the ACP to obtain both intradural and extradural operative fields. With this technique, the ACP can be safely removed without injuring the neurovascular structure, such as the optic nerve and internal carotid artery. As an example of its clinical application, we present a case of a 67-year-old woman with anterior clinoid meningioma and visual deficits. The ACP was safely removed using a high-speed drill without injuring the neurovascular structures. Gross total resection was achieved. Her vision returned to normal postoperatively. ConclusionsUsing our modified technique, the widely reflected dura covers the critical neurovascular structure during the skull base drilling. Therefore, this technique compensates the drawbacks inherent to iAC.

How I do it: management of M2 tear injury caused by drilling during intradural anterior clinoidectomy for microsurgical clipping of intracranial aneurysms.

High-speed drilling is associated with potential injury to neurovascular structures, particularly during intradural drilling of the anterior clinoid process. During an anterior clinoidectomy, a cotton patty and middle cerebral artery branches became inadvertently wrapped around the bit, causing a tear on the inferior M2 trunk. Following temporary clipping of the internal carotid artery, the tear was identified. Temporary clips were placed proximally and distally. The tear was then repaired with interrupted microsutures. Extreme care should be exercised during clinoidectomy. Should small vascular injury occur, direct microsuturing can be a good alternative to sacrificing or implantation anastomosis repair.

Retrograde Suction Decompression for Clipping of a Giant Ophthalmic Internal Carotid Artery Aneurysm: 2-Dimensional Operative Video.

Microsurgical clipping of large paraclinoid aneurysms is challenging because of the complex anatomy of the dural rings, lack of easy proximal control, and wide aneurysm necks. Proximal retrograde suction decompression, or the Dallas technique, can reduce aneurysm turgor and, with aspiration of the trapped cervical and supraclinoid internal carotid arteries (ICAs), can collapse the aneurysm to aid microsurgical clipping.1-5 A woman in her late 30s presented with decreased right-eye visual acuity. Informed written consent was obtained for microsurgical management and publication. Upon cervical exposure of the carotid bifurcation, we performed a standard pterional craniotomy, trans-sylvian exposure, and intradural anterior clinoidectomy. After burst suppression and cross-clamping of the carotid, we inserted an angiocatheter at the common carotid artery (CCA). Distal temporary clips were placed on the posterior communicating artery and C7 ICA. With the cervical ICA unclamped, retrograde suction was continuously applied to deflate the aneurysm. We applied 2 pairs of fenestrated-booster clips to the aneurysm dome and a fifth clip to the aneurysm neck. After restoration of flow, indocyanine green angiography and Doppler assessments were performed. The proximal clip was converted into a curved clip to optimize ICA flow. Postoperative angiography confirmed complete occlusion of the aneurysm. The patient was discharged on postoperative day 3, with stable visual acuity.6 This video demonstrates that retrograde suction decompression via the cervical CCA can be safely performed to facilitate clipping of complex paraclinoid ICA aneurysms. Comprehensive planning of temporary aneurysm trapping for suction decompression and permanent clip construct for aneurysm occlusion are needed for effective aneurysm repair.

Microneurosurgery for Paraclinoid Aneurysms in the Context of Flow Diverters.

The advent of flow diverter (FD) stentshas apparently reduced the role of microneurosurgery for paraclinoid aneurysms despite sparse high-quality evidence about their long-term effects.The present study critically reviews the overall results of a microneurosurgical series of 57 paraclinoid aneurysms.Of these aneurysms, 47.4% were regular in size while 19.3 were giant. Barami type I was predominant. In 21 aneurysms a hemorrhagic onset occurred. Pterional approach with intradural anterior clinoidectomy was preferred by far. Clipping was possible in 91.2% of aneurysms and a high-flow bypass was the choice in five cases. An mRS of 0-2 was achieved in 77.3% of patients, typically <50years old.Visual field appeared improved or unchanged in 36.3% and 63.6% of the symptomatic patients, respectively. In 76.1% of incidental aneurysms, campimetry was unaffected by surgery.A complete aneurysm exclusion was achieved in 93% of cases usinga single procedure. No recurrences were documented on an average follow-up of 54.1±34months.Microneurosurgery is still a valuable, definitive, and durable option for Barami type Ia, Ib, or II paraclinoid aneurysm, especially in patients <50years old and visually symptomatic. Conditions other than these areideal candidates for FD stents.

Anterior Clinoidectomy: Intradural Step-by-Step En Bloc Removal Technique

Anterior clinoidectomy is an important and essential skill for skull base and cerebrovascular neurosurgeons. We present a 1-piece intradural anterior clinoidectomy, providing a step-by-step description of the technique, independently of anatomic variations. Between 2014 and 2020, 128 patients (119 women and 9 men; average age, 54.6 years) underwent intradural anterior clinoidectomy during microsurgical clipping of carotid-ophthalmic aneurysms. The anterior clinoid process continues medially with the planum sphenoidale, over the optic nerve, laterally with the lesser wing of the sphenoid bone, and inferiorly with the optic strut, which is always found anteriorly to the clinoid segment of the internal carotid artery, and separates the optic canal from the superior orbital fissure. The proposed anterior clinoidectomy followed, one after the other, these 3 fixation points for the detachment of the anterior clinoid process. The main indication for intradural anterior clinoidectomy was the management of vascular lesions around paraclinoid (clinoidal and ophthalmic) segments of the internal carotid artery. Complications of the procedure included injury to the internal carotid artery or the ophthalmic artery, thermal damage to the optic nerve, and invasion of the sphenoid sinus or a pneumatized anterior clinoid process, which could lead to postoperative cerebrospinal fluid leakage. The anterior clinoidectomy technique described here minimizes the drilling surface for detachment of the anterior clinoid process and reduces operative time as well as the amount of bone dust produced by drilling. It also precisely delineates the localization of the optic strut, preventing carotid or optic nerve damage.

Microsurgical Clipping of a Ruptured Basilar Apex Aneurysm: 3-Dimensional Operative Video.

A 59-yr-old woman presented with a sudden onset of headache with neck pain and stiffness, Hunt and Hess grade 2. Brain computed tomography (CT) showed subarachnoid hemorrhage, Fisher Grade 2. Intra-arterial digital subtraction angiography (IADSA) showed a basilar artery apex aneurysm, dome size 9 mm and neck 3 mm, leaning towards the right, and a dominant right artery of Percheron. Endovascular treatment and microsurgical clipping were both explained to the patient, but she decided to undergo microsurgery due to the durability of treatment. She underwent a right frontotemporal craniotomy and orbital osteotomy. We performed optic nerve decompression and intradural anterior clinoidectomy to enhance the exposure. Working through the carotid-oculomotor space, the posterior communicating artery was traced back to the posterior cerebral artery. The basilar artery was temporarily occluded for aneurysm dissection after burst suppression to protect the brain. The aneurysm was irregular, multilobulated, and projecting upward. The dominant thalamoperforate artery (artery of Percheron) was arising from the right P1, and densely adherent to the sac of the aneurysm. After dissection of the artery of Percheron away from the aneurysm, it was completely occluded by a side-curved titanium clip. The patient had right oculomotor nerve paresis and headache postoperatively, but at discharge 2 wk later the headache and paresis had completely resolved. The postoperative IADSA showed total occlusion of the aneurysm with patency of the artery of Percheron. This 3-dimensional video shows the technical nuances of microsurgical clipping of a ruptured basilar apex aneurysm and intraoperative dissection of the artery of Percheron. Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

Surgical Strategies for Ruptured Complex Aneurysms Using Skull Base Technique and Revascularization Surgeries.

Object:Surgical clipping of paraclinoid aneurysm, thrombosed large aneurysm, and/or vertebral-basilar dissecting aneurysms can be very difficult and has relatively high morbidity. We describe our experience using skull base and bypass technique and discuss the advantages and its pitfalls.Patients and Methods:We retrospectively reviewed medical charts of 22 consecutive patients with complex aneurysmal lesions underwent skull base and/or bypass techniques between March 2012 and April 2017.Results:There were 5 patients with paraclinoid or internal carotid artery (ICA) aneurysm underwent modified extradural temporopolar approach with mini-peeling of the dura propria with suction decompression, 3 patients with ICA aneurysm underwent intradural anterior clinoidectomy, 12 patients with vertebral dissecting aneurysm through transcondylar fossa approach (6 patients underwent occipital artery-posterior inferior cerebellar artery [OA-PICA] bypass), 1 patients with vertebral artery dissection underwent superficial temporal artery-superior cerebellar artery and OA-PICA bypass through posterior transpetrosal approach, 1 patient with arteriovenous fistula at the ventral side of the craniovertebral junction through extremely far lateral approach. Surgical outcome was good recovery in 10 patients, moderate disability in 4, severe disability in 4, vegetative state in 2, and dead is 2 patients. The favorable outcome was 63.6%, and poor outcome was 36.4%, which showed poor grade subarachnoid hemorrhagic patients. No patient suffered any complication related to re-rupture and/or incomplete clipping.Conclusion:Skull base technique, which can create a wide and shallow operative space, allowed us to improve surgical outcome and to reduce the risk of intraoperative neurovascular injury for surgical treatment of deeply located complex aneurysms.

Anterior clinoidectomy for paraclinoid aneurysms in Helsinki Neurosurgery.

Background:In this video abstract, we present an intradural anterior clinoidectomy for management of some paraclinoid aneurysms. Quick adenosine cardiac arrest performed instead of an anterior clinoidectomy and proximal temporary clipping usually allows us a proximal control of aneurysms in Helsinki Neurosurgery. However, when the neck of the aneurysm remains hidden under the anterior clinoid process, or when some complex aneurysms have reduced space for placing temporary clips obstructing the definitive clipping, anterior clinoidectomy is the most available option.Technique:The patient with multiple intracranial aneurysms had a ruptured anterior cerebral artery aneurysm associated with a right middle cerebral artery aneurysm and a right small paraclinoid aneurysm. The patient underwent surgical clipping of all aneurysms by a right lateral supraorbital approach at one-stage surgery. After the associated aneurysms were clipped, the hidden paraclinoid aneurysm required an anterior clinoidectomy for definitive clipping. A small durotomy over the anterior clinoid process was made with microscissors after bipolar coagulation. Subsequently, the anterior clinoidectomy was performed under visual control with the use of an electric high-speed diamond drill (3 mm diameter). The direction and size of the drilling were performed according to the anatomical configuration and exact location of the aneurysm determined by the preoperative radiological analysis of the case. A definitive clip was applied after complete visualization of aneurysm. Postoperative computed tomography angiography demonstrated absence of complications.Conclusion:Anterior clinoidectomy is a useful procedure aiming at a proper definitive clipping of paraclinoid aneurysms with challenging locations and configurations.Videolink:http://surgicalneurologyint.com/videogallery/right-clinoidectomy/

Superficial Temporal Artery-Sparing Mini-Pterional Approach for Cerebral Aneurysm Surgery.

ObjectiveThe purposes of this study were to introduce a superficial temporal artery (STA)-sparing mini-pterional approach for the treatment of cerebral aneurysms and review the surgical results of this approach.MethodsBetween June 2010 and December 2015, we performed the STA-sparing mini-pterional approach for 117 patients with 141 unruptured intracranial aneurysms. We analyzed demographic, radiologic, and clinical variables including age, sex, craniotomy size, aneurysm location, height of STA bifurcation, and postoperative complications.ResultsThe mean age of patients was 58.4 years. The height of STA bifurcation from the superior border of the zygomatic arch was 20.5 mm±10.0 (standard deviation [SD]). The craniotomy size was 1051.6 mm2±206.5 (SD). Aneurysm neck clipping was possible in all cases. Intradural anterior clinoidectomy was performed in four cases. Contralateral approaches to aneurysms were adopted for four cases. Surgery-related complications occurred in two cases. Permanent morbidity occurred in one case.ConclusionOur STA-sparing mini-pterional approach for surgical treatment of cerebral aneurysms is easy to learn and has the advantages of small incision, STA sparing, and a relatively wide surgical field. It may be a good alternative to the conventional pterional approach for treating cerebral aneurysms.

Optic Nerve Surface Temperature during Intradural Anterior Clinoidectomy: A Comparison Between High-Speed Diamond Burr and Ultrasonic Bone Curette

Background: Ultrasonic bone curettes are increasingly used in cranial base surgery. The heat generated by these devices during anterior clinoidectomy has not been evaluated.

Microsurgical treatment of ophthalmic segment aneurysms

Ophthalmic segment aneurysms refer to superior hypophyseal artery aneurysms, true ophthalmic artery aneurysms, and their dorsal variant. Indications for treatment of these aneurysms include concerning morphological features, large size, visual loss, or rupture. Although narrow-necked aneurysms are ideal endovascular targets, more complex and larger lesions necessitating adjunctive stent or flow-diversion techniques may be suitably treated with long-lasting, effective clip ligation instead. This is particularly relevant in the consideration of ruptured ophthalmic segment aneurysms. This article provides a depiction of microsurgical treatment of ophthalmic segment aneurysms with an accompanying video demonstration. Emphasis is placed on microsurgical anatomy, the intradural anterior clinoidectomy and clipping technique. The intradural anterior clinoidectomy, demonstrated in detail in our Supplementary video, provides significant added exposure of the ophthalmic segment of the internal carotid artery, allowing for improved aneurysm visualization. In the management of superior hypophyseal artery aneurysms, emphasis is placed on identifying and preserving superior hypophyseal artery perforators, using serial fenestrated straight clips rather than a single right-angled fenestrated clip to obliterate the aneurysm. Post-clipping indocyanine green dye angiography is a crucial tool to confirm aneurysm obliteration and the preservation of the parent vasculature and adjacent superior hypophyseal artery perforators. With careful attention to the nuances of microsurgical clipping of ophthalmic segment aneurysms, rewarding results can be obtained.

Clinoidectomía anterior intradural: Estudio anatomo-clínico y utilidad en el tratamiento de los aneurismas paraclinoideos trans-segmentarios C5-C6

To present an anatomoclinical study of the intradural anterior clinoidectomy and to evaluate the usefulness of this procedure in the microsurgical management of paraclinoid aneurysms. To describe two cases of a subtype of paraclinoid aneurysms arising from and with their fundus growing both in the clinoidal and subarachnoidal segments of the internal carotid artery (paraclinoid trans-segmentary C5-C6 aneurysms). The microanatomy of the clinodal region has been studied in dried and fixed specimens. The steps of the intradural anterior clinoidectomy are showed. The imaging and microsurgical findings in two cases of trans-segmentary C5-C6 aneurysms are also described. The C5 clinoid segment of the internal carotid artery is exposed intradurally after anterior intradural clinoidectomy. The transtion between the C5 clinoid and C6 ophthalmic is also exposed and it is movilized only after the section of the carotid distal ring. These manoeuvres allows the microsurgical management and dipping of the trans-segmentary C5-05 aneurysms. The nomenclature of the internal carotid artery segments and paraclinoid aneurysms remains confuse. Therefore, each lesion should be idetified by the location of the neck (extradural: C4 and C5 segments; intradural: C6 segment), fundus projection and location (intradural / extradural). The microsurgical clipping of the paraclinoid aneurysms is made easier after intradural anterior clinoidectomy, but this manoeuvre is mandatory for trans-segmentary C5-C6 lesions.

Ultrasonic bone curettage for optic canal unroofing and anterior clinoidectomy

Extradural unroofing of the optic canal and subsequent mobilization of the optic nerve is a useful technique in the surgical treatment of parasellar tumors; however, the drilling procedure itself is associated with the risk of optic nerve damage. A safer technique would certainly be beneficial. The ultrasonic bone curette is a device developed in Japan for safer bone removal. Its use in intradural anterior clinoidectomy and opening of the internal auditory meatus has been reported before. In this article the authors describe their experience in using this device for extradural unroofing of the optic canal in patients with parasellar tumors. Between March 2002 and November 2004, the aforementioned technique was used in the treatment of eight patients with parasellar tumors. After undertaking a frontotemporal craniotomy and orbital osteotomy, an ultrasonic bone curette was used to unroof the optic canal via an epidural approach; in five cases anterior clinoidectomy was added subsequently. Using an ultrasonic bone curette, unroofing of the optic canal was completed safely and required much less expertise than that required for standard drilling. The mortality and major morbidity rates were 0%. The visual function outcome was satisfactory, with the overall visual status improving in all seven patients in whom this symptom was present preoperatively. The ultrasonic bone curette makes the unroofing of the optic canal safer and easier, possibly improving the visual outcome of patients undergoing surgery for parasellar tumors.