Carotid Cave Research Articles

The Transorbital Approach to the Internal Carotid and Middle Cerebral Arteries. A Dissection Study towards Targeted Access Aneurysm Clipping

BackgroundThe application of the transorbital approach (TO) for vascular lesions has been scarcely explored. In this anatomical experience, we examine the carotid and middle cerebral arteries from the TO perspective and investigate the feasibility for vascular clipping in a pseudo-vascularised model. MethodsThree fixed human cadaveric specimens (six sides) were used for dissection. A sequential TO approach: 1) conventional lateral orbital craniectomy; 2) lateral orbital rim removal; 3) anterior clinoidectomy. The clinoidal, ophthalmic and communicating carotid segments, branches, related cranial nerves and dural attachments were examined. Comparison between the three variations of bone removal determined the minimal necessary steps for each vascular segment. An additional fresh pseudo-vascularised specimen (two sides) was used to test surgical feasibility of clipping. ResultsThe TO approach allowed to expose the carotid C4 to bifurcation. Clinoidectomy and dural rings opening exposed lateral and dorsal aspects of C5/C6 and the ophthalmic, but not medial or ventral aspects, neither the superior hypophyseal artery nor the carotid cave. Posterior communicating artery could be followed from origin to end. The anterior choroidal origin was seen but disappeared behind the uncus. The carotid bifurcation was visible, M1 could be followed to its bifurcation, but A1 lied deep within the field. The corridor permitted arachnoidal dissection, vessel manipulation and clipping of exposed segments. ConclusionThe TO approach provides anatomical access to lateral and dorsal carotid siphon, complete posterior communicating and proximal middle cerebral artery. This preliminary experience suggests potential application in the elective treatment of paraclinoid and posterior communicating aneurysms.

Management of Incidental Carotid Cave Aneurysm.

Incidental diagnosis of saccular aneurysms is more common with the advent of imaging techniques. Because of the severe morbidity and mortality that they can cause, treatment is chased for them, either microsurgical treatment or endovascular, even when they are diagnosed incidentally. Carotid cave aneurysms are rare, and they seem to have a more benign course compared to other intracranial aneurysms, probably related to the physical enveloping effect of the surrounding structures. Yet, their microsurgical treatment is a serious challenge technically for the neurosurgeon, with its severe morbidity and mortality for the patient. Endovascular techniques have their risks, too. In this paper, we analyzed and presented our series of incidentally diagnosed carotid cave aneurysms. The age, gender of patients, the size, laterality, and MR angiographic follow-up of aneurysms were reported. Their clinical results were noted. Fifty-six patients who had incidentally been diagnosed with 59 carotid cave aneurysms were followed up. No patient was microsurgically treated, but 15 patients had endovascular treatment for 15 aneurysms. The mean size of 15 treated aneurysms was 4.6 ± 2.1 (range = 2-10) mm, and it was 3.0 ± 1.5 (range = 1.7-10) mm for the untreated aneurysms (n = 44). There was no significant difference between the follow-up times of the treated and untreated groups (P = 0.487). The median follow-up of 59 aneurysms in 56 patients was 52 (mean = 49.6 ± 27.9, range = 1-124) months, with a total follow-up of 244 aneurysm years. None of the patients had subarachnoid hemorrhage related to carotid cave aneurysms during follow-up, and none of the aneurysms had shown growth. Two patients who had endovascular treatment had ischemic complications with minor neurologic deficits. Follow-up can be a reasonable option for the incidental aneurysms that are located and confined to the carotid cave. Additionally, TOF might be a reliable method for follow-up imaging of carotid cave aneurysms.

The Lateral Supraorbital Approach: 2-Dimensional Operative Video.

The lateral supraorbital approach (LSO), a minimally invasive alternative to the pterional approach, can be used for anterior circulation aneurysms (except distal anterior cerebral artery), some posterior circulation aneurysms, and tumors located around the sellar and suprasellar regions. Performing one-layer myocutaneous flap that is retracted anteriorly, exposure of the superior temporal line, and zygomatic process of the frontal bone and the inferior limit of the craniotomy represent the upper edge of the Sylvian fissure, exposing the anterolateral skull base. Skin incision behind the hairline, one-layer myocutaneous flap retracted anteriorly, minimal detachment of the temporalis muscle, burr hole over the superior temporal line, and craniotomy of 4 cm in diameter (inferior limit of the craniotomy represents the Sylvian fissure). Potential risks include opening of the frontal sinus, entering the orbit and exposure of the orbital fat, wrong craniotomy location, and limited exposure. Inadequate craniotomy size limits instruments maneuverability. To avoid complication, identification of anatomic landmarks, sinus closure, preoperative evaluation of computed tomography scans, and use of neuronavigation are necessary. This requires surgical expertise and familiarity of minimal invasive craniotomies. Anatomic limitations of the LSO include temporomesial region, distal Sylvian +/-, posterior communicating artery aneurysms medial projection, retro carotid space, and carotid cave. For pathologies requiring an additional lateral trajectory, we use an extended LSO, drilling the sphenoid wing through the fronto-pterio-orbital window without drilling of the temporal bone. Additional variations include performing an intradural or extradural clinoidectomy. The patient consented to the procedure and to the publication of their image.

Tailored Surgical Access to the Cavernous Sinus and Parasellar Region: Assessment of Cavernous Sinus Entry Corridors and the Periclinoid and Pericavernous Surgical Maneuvers

Lesions involving the cavernous sinus (CS) represent some of the most challenging pathologies of the skull base owing to the dense traversing and surrounding neurovasculature. Extradural exposure and preparation of this region, whether as initial preparation for a combined intra-extradural approach or as the main avenue of surgical exposure, can enlarge surgical corridors and minimize the need for brain retraction in this very confined space. We provide a detailed assessment of the entry corridors to the CS that are available within each approach, the surgical exposure and freedom provided by each of these corridors, and demonstrate how extradural and intradural preparation of these corridors can be used to widen the available working space and facilitate surgery. Pterional, frontotemporal-orbital, frontotemporal-orbitozygomatic, frontotemporal-zygomatic, perilabyrinthine transtentorial, and endoscopic transnasal transsphenoidal approaches were performed on cadaveric heads to access the perisellar and CS regions. Periclinoid maneuvers (extradural cutting of the meningo-orbital band, anterior clinoidectomy, unroofing of the optic canal, opening of the superior orbital fissure, displacement of the extra-annular structures, opening of the annulus of Zinn, and interdural dissection), pericavernous maneuvers (intradural cutting of the distal dural ring, mobilization of the supraclinoid internal carotid artery, opening of the oculomotor porus, and mobilization of cranial nerve (CN) III), peritrigeminal extensions (extradural mobilization of CN V2 [maxillary] and/or V3 [mandibular]), and other surgical maneuvers were performed and evaluated. The CS was divided into 8 anatomical compartments and 9 entry corridors were described, and exposure and freedom were assessed accordingly. Intradurally, the standard unextended pterional, frontotemporal-orbital, and frontotemporal orbitozygomatic transsylvian approaches provided access solely to the parasellar entry corridor into the superior wall of the CS. Expanding these approaches with extradural periclinoid maneuvers allowed for subsequent application of the intradural pericavernous maneuvers and enlargement of the parasellar corridor and exposure of the carotid cave. Extradurally, the frontotemporal-orbital approach could be expanded via application of periclinoid maneuvers, which provided access to the anterior portions of the main lateral wall entry corridors. The frontotemporal-orbitozygomatic approach could also be expanded with periclinoid maneuvers to provide extradural access to all 6 lateral wall entry corridors. The extradural frontotemporal-zygomatic approach only provided exposure following interdural dissection, which allowed for access to the inferolateral entry corridors into the lateral wall. Extradural peritrigeminal extension in the frontotemporal-orbitozygomatic and frontotemporal-zygomatic approaches allows for enlargement of the supramaxillary and pre- and postmandibular corridors. The perilabyrinthine approach to the posterior wall was enlarged with opening of Dorello's canal and the endoscopic transnasal transsphenoidal approach was enlarged with opening of the optic canal. Targeted extradural preparation optimizes exposure and significantly improves access to deep-seated targets by enhancing surgical maneuverability through the unlocking of neurovascular structures and widening of surgical corridors without the need for additional brain retraction.

Extradural anterior clinoidectomy versus endoscopic transplanum-transcavernous approach to the paraclinoid region: quantitative anatomical exposure analysis.

Transcranial anterior clinoidectomy is a conventional microsurgical approach for treatment of paraclinoid aneurysms. The endoscopic endonasal approach (EEA) is an alternative method for clipping intracranial aneurysms. No analysis has been conducted to anatomically compare approaches with respect to treating paraclinoid aneurysms. The surgical anatomical exposures of the paraclinoid region during transcranial extradural anterior clinoidectomy (EAC) and the endoscopic endonasal transplanum-cavernous approach (EETC) are described and quantitatively assessed. Seven cadaveric heads underwent EAC and EETC. Measurements included the area of exposure, volume of surgical freedom, angle of attack, ophthalmic artery (OphA) origin, and coronal exposure angle of the internal carotid artery (ICA). The EETC provided a larger area of exposure than the EAC (100.1±24.9 vs 76.1±12.9 mm2, p = 0.04). The EAC provided a higher volume of surgical freedom and greater angle of attack than the EETC in all neurovascular parameters, including the OphA, superior hypophyseal artery (SHA), distal ICA, and distal dural ring (all p < 0.001). The OphA origin was intradural in 85.7% and extradural in 14.3% of specimens. With regard to the coronal angle of exposure, the EAC exposed the OphA and SHA in the upper lateral quadrant (67.9±7.8° and 80.6±4.5°, respectively) and the distal ICA in the upper medial and upper lateral quadrants (92±7.5°). The EEA exposed the OphA, SHA, and distal ICA in the upper medial and lower medial quadrants (130.4±10.7°, 68.4±10.8°, and 58±11.4°, respectively). The EAC and EETC each offer specific advantages for paraclinoid region exposure. The EAC is appropriate for paraclinoid aneurysms that occur at the dorsolateral surface of the paraclinoid ICA. The EETC is an alternative approach for aneurysms that occur along medial surface of the paraclinoid ICA (e.g., carotid cave and SHA aneurysms). The EETC provides greater surgical exposure to the medial aspect of the paraclinoid ICA.

How I do it: proximal control in parkinson\u2019s triangle for a very large paraclinoid aneurysm

BackgroundParaclinoid aneurysms, especially when they are large, can be quite difficult to treat, both endovascularly and through microsurgical clip reconstruction. There are many possibilities to approach this region surgically, and most hinge on total or partial removal of the anterior clinoid process. Gaining proximal control may be a challenge when space is limited, which is why Parkinson’s triangle may be a viable alternative in some cases.MethodsWe describe in a stepwise fashion the steps used to reconstruct a very large paraclinoid aneurysm. We first attempted to gain proximal control in the carotid cave and later in Parkinson’s triangle because of limited manoeuvrability.ConclusionProximal control in Parkinson’s triangle can be a safe alternative when the post-clinoidal segment of the internal carotid artery (ICA) is short and working space is limited in paraclinoid aneurysm microsurgical clip reconstruction.

English

Cerebral aneurysms are pathological focal dilatations of cerebral vasculature that are prone to rupture1. Pathogenesis involves aberrations of cerebral vasculature resulting in compromised integrity of internal elastic lamina with associated defects in adjacent media and adventia.1 Apart from posterior communicating artery aneurysm, internal carotid artery aneurysms account for 4 % of all cerebral aneurysms.2 Paraclinoid aneurysms are defined as those originating from the ICA between the infra clinoid portion (C3) and proximal of the posterior communicating artery. Their classification is given by Al Rodhan3 is as follows: Type Ia – superior hypophyseal, type Ib – ventral paraclinoid, type II – true ophthalmic, type III – carotid cave, type IV – transitional, type V – intra cavernous. In literature many cases of cerebral aneurysms presenting with visual symptoms have been reported 4 in which, aneurysms were located on internal carotid artery near ophthalmic artery called as paraclinoid aneurysms. The unruptured cerebral aneurysms cause mass effect hence producing symptoms of nausea, vomiting and severe headache and later on by compressing surrounding cranial nerves produce ocular symptoms like ophthalmoplegia and ptosis. The aneurysms may rupture and result in intracranial bleed which again by mass effect can produce the above told symptoms. We report a case of unruptured intracranial aneurysm presenting with total ophthalmoplegia with visual deficit as the primary symptom.

Retrospective review of 290 small carotid cave aneurysms over 17 years.

The carotid cave is a unique intradural region located along the medial aspect of the internal carotid artery. Small carotid cave aneurysms confined within this space are bound by the carotid sulcus of the sphenoid bone and are thought to have a low risk of rupture or growth. However, there is a lack of data on the natural history of this subset of aneurysms. The authors present a retrospective case series of 290 small (≤ 4 mm) carotid cave aneurysms evaluated and managed at their institution between January 2000 and June 2017. No patient presented with a subarachnoid hemorrhage attributable to a carotid cave aneurysm, and there were no instances of aneurysm rupture or growth during 911.0 aneurysm-years of clinical follow-up or 726.3 aneurysm-years of imaging follow-up, respectively. This series demonstrates the benign nature of small carotid cave aneurysms.

The Superior Hypophyseal Arteries: Anatomical Study with an Endoscopic Endonasal Perspective.

The use of high-definition endoscopes in extended transsphenoidal approaches to the suprasellar area has significantly improved visualization of its vascularization. To systematically examine the superior hypophyseal arteries (SHAs) anatomy from an endonasal endoscopic perspective. The endoscopic endonasal transsphenoidal trans-tuberculum approach was performed in 19 adult, fresh and latex injected specimens. Dissections recordings were reviewed to analyze SHAs type, number, and branches, as well as internal carotid arteries (ICA) branches that vascularized optic nerves and chiasm. Identification of SHAs was possible in all specimens (37/38 sides). The number of SHAs varied from 1 to 3 per side (mean: 1.7). The anterior superior hypophyseal artery was visible in almost all cases (35/37 sides) and originated at the level of the carotid cave in 18/35 specimens; number of branches ranged from 1 to 6 (mean: 3.5), directed to the optic nerve (86%), chiasm (57%), infundibulum (86%), and/or parallel to the pituitary stalk (74%). The 4 main branches and patterns, originally described by McConnell in 1953, were confirmed. The posterior superior hypophyseal artery was evident in 28/37 sides with number of branches ranging from 0 to 4 (mean: 2.1), directed to the optic chiasm (50%), optic tract (32%), infundibulum (79%), and/or pituitary stalk (36%). The surgical implications of this study, together with anatomical and clinical videos, are also briefly discussed. SHAs constitute a complex of anterior and posterior branches that stem from the medial ICA with different patterns, vascularizing the optic apparatus and pituitary stalk.

Surgical anatomy of the superior hypophyseal artery and its relevance for endoscopic endonasal surgery.

The endoscopic endonasal approach has become a routine corridor to the suprasellar region. The superior hypophyseal arteries (SHAs) are intimately related to lesions in the suprasellar space, such as craniopharyngiomas and meningiomas. Here the authors investigate the surgical anatomy and variations of the SHA from the endoscopic endonasal perspective. Thirty anatomical specimens with vascular injection were used for endoscopic endonasal dissection. The number of SHAs and their origin, course, branching, anastomoses, and areas of supply were collected and analyzed. A total of 110 SHAs arising from 60 internal carotid arteries (ICAs), or 1.83 SHAs per ICA (range 0-3), were found. The most proximal SHA always ran in the preinfundibular space and provided the major blood supply to the infundibulum, optic chiasm, and proximal optic nerve; it was defined as the primary SHA (pSHA). The more distal SHA(s), present in 78.3% of sides, ran in the retroinfundibular space and supplied the stalk and may also supply the tuber cinereum and optic tracts. In the two sides (3.3%) in which no SHA was present, the territory was covered by a pair of infundibular arteries originating from the posterior communicating artery. Two-thirds of the pSHAs originated proximal to the distal dural ring; half of these arose from the carotid cave portion of the ICA, whereas the other half originated proximal to the cave. Four branching patterns of the pSHA were recognized, with the most common pattern (41.7%) consisting of three or more branches with a tree-like pattern. Descending branches were absent in 25% of cases. Preinfundibular anastomoses between pSHAs were found in all specimens. Anastomoses between the pSHA and the secondary SHA (sSHA) or the infundibular arteries were found in 75% cases. The first SHA almost always supplies the infundibulum, optic chiasm, and proximal optic nerve and represents the pSHA. Compromising this artery can cause a visual deficit. Unilateral injury to the pSHA is less likely to cause an endocrine deficit given the artery's abundant anastomoses. A detailed understanding of the surgical anatomy of the SHA and its many variations may help surgeons when approaching challenging lesions in the suprasellar region.

A literature review concerning contralateral approaches to paraclinoid internal carotid artery aneurysms

Ipsilateral approaches remain the standard technique for clipping paraclinoid aneurysms. Surgeons must however be prepared to deal with bony and neural structures restricting accessibility. The application of a contralateral approach has been proposed claiming that some structures in the region can be better exposed from this side. Yet, only few case series have been published evaluating this approach, and there is a lack of systematic reviews assessing its specific advantages and disadvantages. We performed a structured literature search and identified 19 relevant publications summarizing 138 paraclinoid aneurysms operated via a contralateral approach. Patient's age ranged from 19 to 79years. Aneurysm size mainly varied between 2 and 10mm and only three articles reported larger aneurysms. Most aneurysms were located at the origin of the ophthalmic artery, followed by the superior hypophyseal artery and carotid cave. All aneurysm protruded from the medial aspect of the carotid artery. Interestingly, minimal or even no optic nerve mobilization was required during exposure from the contralateral side. Strategies to achieve proximal control of the carotid artery were balloon occlusion and clinoid segment or cervical carotid exposure. Successful aneurysm occlusion was achieved in 135 cases, while 3 ophthalmic aneurysms had to be wrapped only. Complications including visual deterioration, CSF fistula, wound infection, vasospasm, artery dissection, infarction, and anosmia occurred in a low percentage of cases. We conclude that a contralateral approach can be effective and should be considered for clipping carefully selected cases of unruptured aneurysms arising from medial aspects of the above listed vessels.

Case report of 2 Carotid cave aneurysms: Microsurgical anatomy and technical pitfalls

Case report of 2 Carotid cave aneurysms: Microsurgical anatomy and technical pitfalls

Anatomia Microcirúrgica do Segmento Clinóide da Artéria Carótida Interna e do Cavo Carotídeo

Embora a região clinóide seja comumente abordada pelos neurocirurgiões em várias afecções, sua anatomia e extremamente complexa e variável. O segmento clinóide da artéria carótida interna (ACI) se encontra na transição entre o seio cavernoso e o espaço subaracnóide, limitado pelos dois anéis durais. O segmento posteromedial do anel dural distal não tem contato com nenhuma estrutura óssea, esta peculiaridade anatômica facilita a formação do cavo carotídeo. Os anéis proximal e distal tornam-se relevantes por serem os limitesanatômicos. O entendimento do segmento clinóide é importante para o correto diagnóstico e abordagem dos aneurismas desta região. Controle proximal, clinoidectomia anterior, opções de clips fenestrados e auxílio do endoscópio são detalhes técnicos de grande utilidade no manejo dos aneurismas do cavo carotídeo.

Endovascular treatment of unruptured carotid cave aneurysms

Objective To summarize the characteristics of carotid cave aneurysms and to investigate the safety and efficacy of endovascular treatment for this kind of aneurysms. Methods From November 2013 to November 2016, the clinical data of 22 patients with unruptured carotid cave aneurysms undergoing endovascular treatment, at the Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical University, were collected. Among them, 3 patients (14%) were male and 19 patients (86%) were female. Their clinical characteristics, outcomes, complications and follow-up results were analyzed retrospectively. Modified Rankin scale (mRS) was used to assess the outcomes and Raymond Scale was used to assess the safety and efficacy of endovascular treatment. Results All 22 patients were treated by stent assisted coiling. Raymond 1 was reported in 19 patients (86%) and Raymond 2 was achieved in 3 patients (14%). Thrombosis occurred in the stent in 1 patient during the operation who did not develop any neurological deficits after Tirofiban treatment. Ten patients underwent angiographic follow-up after 1 year and 9 patients achieved Raymond 1. The mRs score was 0 in all patients. Conclusions Carotid cave aneurysms seem to be more common in females. Endovascular treatment could be a safe and effective approach for carotid artery aneurysms. Key words: Intracranial aneurysm; Carotid cave; Endovascular procedures; Treatment outcome

Surgical clipping for large and giant unruptured paraclinoid aneurysms in hybrid operation theater

Objective To evaluate the clinical value and outcomes of surgical clipping for large and giant unruptured paraclinoid aneurysms. Methods A retrospective analysis was conducted on 8 patients (11 aneurysms) who underwent aneurysm clipping assisted with balloon occlusion in hybrid operation theatre at Neurosurgery Department of Xuanwu Hospital, Capital Medical University, from January 2014 to March 2017. All patients were females whose average age was 54.9±5.7 years. Results Among 11 aneurysms in this series, a total of 9 aneurysms were treated and included 8 large or giant paraclinoid aneurysms and 1 carotid cave aneurysm. Intraoperative radiography demonstrated that all 9 aneurysms were successfully obliterated, 1 patient developed occlusion of parent artery and 1 had severe stenosis of parent artery. Three patients encountered ischemic events postoperatively. The assessment at discharge indicated a Glasgow Outcome Score (GOS) of 5 in 5 patients, 4 in 1 case and 3 in 2 cases. At the follow-up which was conducted 1.5-39.5 [average: 10.7 (P25: 3.2, P75: 32.3)] months post operation, a GOS of 5 was reported 7 patients and 4 in 1 case. Vision acuity was improved in 7 patients and remained stable in 1 case. Conclusion Hybrid surgery seems to be able to facilitate clipping of large and giant unruptured paraclinoid aneurysms, but more studies are needed for exploration of proper interventional devices and methods. Key words: Intracranial aneurysm; Carotid artery, internal; Paraclinoid; Hybrid operation; Balloon occlusion; Surgical clipping

Risk Factors for Visual Impairments in Patients with Unruptured Intradural Paraclinoid Aneurysms Treated by Neck Clipping without Bypass Surgery

Although paraclinoid aneurysms are now frequently referred for endovascular treatment, the durability of obliteration is still to be determined. Therefore, direct surgery for paraclinoid aneurysms still remains indispensable. The present study aimed to evaluate the risk factors for the visual impairments in patients with unruptured intradural paraclinoid aneurysms. The data of 133 patients with 136 aneurysms treated by neck clipping without bypass surgery was evaluated. Visual impairments included decreased visual acuity and visual field defect. The aneurysm was classified into superior projecting aneurysm, ventral projecting aneurysm, and carotid cave aneurysm. Plug-in method was defined as filling interspace, which was formed between the internal carotid artery and the sutured dura in case of detachment of the dural ring. Postoperative new visual impairments were observed in 30 aneurysms (22%). During the follow-up period (median, 600 days), postoperative new visual impairments continued in 23 aneurysms (17%). Multivariate analysis showed that carotid cave location and plug-in method were related to new visual impairments at 30 days (odds ratio [OR], 2.6; 95% confidence interval [CI] 1.1-6.1; P= 0.031 and OR, 4.1; 95% CI 1.4-12; P= 0.008) and at 6 months (OR, 4.1; 95% CI 1.5-11; P= 0.005 and OR, 3.3; 95% CI 1.1-11; P= 0.045). The present study showed that carotid cave location and plug-in method during dural closures were related to postoperative continued visual impairments. Neurosurgeons should carefully consider the surgical indication for unruptured carotid cave aneurysms and avoid plug-in methods.

Prevention of Visual Function in the Operation of Paraclinoid Aneurysms

Objective: Paraclinoid aneurysms are aneurysms of the internal carotid artery (ICA) around the anterior clinoid process (ACP), including carotid cave and IC-ophthalmic aneurysms. To treat those aneurysms by direct clipping, it would need the removal of ACP and opening of the external dural ring, which might harm the optic nerves and their function. Then, the endovascular surgery is sometimes recommended especially in the case with carotid cave aneurysm. However, the recent paper reported that the complication and recurrence rates of endovascular surgery are relatively high. This direct surgery is useful, but difficult for the young and middle surgeon because those aneurysms are rare and dangerous lesion. We reviewed our recent cases and assessed the pitfall for prevention of visual function. Method: A total of eight cases with paraclinoid aneurysms treated in our hospital since December 2012 are assessed. Result: One case was treated by endovascular and seven were treated by direct surgery. Five cases were completely clipped with the removal of ACP, however, one of five showed visual impairment after surgery. In this case with right carotid cave aneurysm, ICG-VA during the surgery had shown disappearance of aneurysm and patency of ICA and perforators, however, her right vision gradually worsened 2days after surgery. Right ophthalmic artery was patent on her MRI/MRA and 3D-CTA, and her right optic disc was normal. Operative video was assessed, and showed that her right optic was contracted to ICA during the dissection of aneurysm and ophthalmic artery because of incomplete cutting of falcifalm fold, suggesting that this physiological compression to the optic nerve might cause the visual function. Conclusion: For prevention of visual function in the surgery of paraclinoid aneurysms, the complete opening of dural ring, the removal of optic strut, and the appropriate cutting of falcifalm fold are important as well as the removal of ACP. We emphasize that those techniques are essential as well as the removal of ACP to mobilize the optic nerve and perform the safe surgery.

Pyoderma gangrenosum granulomateux profond : une forme originale de pyoderma gangrenosum ?

We report an extremely rare case of pyoderma gangrenosum with the clinical features of pyoderma gangrenosum but with unusual histopathological findings and deep massive granulomatous infiltration through the dermis. A 15-year-old girl presented with a two-month history of deep ulcers on the lower legs and forehead. She also presented abdominal pain with diarrhea and vomiting that disappeared after symptomatic treatment. Histology showed extensive granulomatous infiltration in the dermis and hypodermis and a micro-abscess in the dermis. An abdominopelvic CT scan revealed peritoneal fluid and tissue formation in a lateral carotid cave (6.56 cm/4.56 cm). Colonoscopy was normal. The patient was treated with oral prednisone, resulting in resolution of the problems of cutaneous lesions, peritoneal fluid and tissue formation. Our case involves a rare presentation of pyoderma gangrenosum (PG) inconsistent with any of the four clinical variants of PG and characterized histologically by the presence of deep granulomas in the dermis and hypodermis. Despite the atypical clinical presentation and unusual histopathological findings, PG seemed the most likely diagnosis after infectious diseases had been ruled out; the good outcome achieved with oral corticosteroids supported our diagnosis.

Quantitative analysis of variable extent of anterior clinoidectomy with intradural and extradural approaches: 3-dimensional analysis and cadaver dissection.

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 clinoidectomy provides a 2.5-times larger area and 2.7-times 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. 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.

Prevention of Visual Function in the Direct Surgery of Paraclinoid Aneurysms

Objective: For paraclinoid aneurysms, especially carotid cave aneurysm, endovascular intervention is recommendable. However, recent publication revealed that its rates of complication and recurrence are relatively high. Direct surgery, which could be useful, might be difficult for the young surgeon because those aneurysms are rare. One of seven cases with paraclinoid aneurysm treated at our department in 2013 deteriorated her vision 2 days after surgery. The problems are evaluated and discussed. Patient: A 54-year-old female patient with right carotid cave aneurysm had received the direct surgery with intradural ACP removal. Aneurysm had completely been closed with curved fenestrate clip. Intraoperative ICG showed disappearance of aneurysm and patency of arteries. Her right vision suddenly deteriorated 2 days later, although her MRI, MRA, and 3D-CTA showed patency of arteries including right opthalmic artery. Results: Operative video revealed that optic nerve had been contracted toward to ICA during dissection of aneurysm and opthalmic artery. It is suggested that this physical contraction could cause the optic nerve injury. Hence, the complete excision of distal dural ring, removal of optic strut and appropriate dissection of falcifalm fold might be important to easily mobilize ICA and prevent injury. Conclusions: Importance of other procedures including dural ring excision should be emphasized as well as ACP removal to complete safe surgery and prevent visual function.