The diagnostic accuracy of MRI in determining the relations between paraclinoid aneurysms and the cavernous sinus

Purpose The location of paraclinoid aneurysms is determinant for evaluation of its intradural compartment and risk of SAH after rupture. Advanced MRI techniques have provided clear visualization of the distal dural ring (DDR) to determine whether an aneurysm is intracavernous, transitional or intradural for decision-making. We analyzed the diagnostic accuracy of MRI in predicting whether a paraclinoid aneurysm is intracavernous, transitional or intradural. Methods We conducted a prospective cohort between January 2014 and December 2018. Patients with paraclinoid aneurysms underwent 3D fast spin-echo MRI sequence before surgical treatment. The DDR was the landmark for MRI characterization of the aneurysms as follow: (i) Intradural; (ii) Transitional; and (iii) Intracavernous. The MRI sensitivity, specificity, positive and negative likelihood ratios were determined compared to the intraoperative findings. We also evaluated the intertechnique agreement using the Cohen’s kappa coefficient (κ) for dichotomous classifications (cavernous vs non-cavernous). Results Twenty patients were included in the cohort. The accuracy of MRI showed a sensitivity of 86.7% (95%CI:59.5–98.3) and specificity of 90.0% (95%CI:55.5–99.8). Analyzing only patients without history of SAH, accuracy test improved with a sensitivity of 92.3% (95%CI:63.9–99.8) and specificity reached 100% (95%CI: 63–100). Values of Cohen’s kappa (κ), intertechnique agreement was considered substantial for dichotomous classifications (κ = 0.754; p < 0.001). For patients without previous SAH, intertechnique agreement was even more coincident for the dichotomous classification (κ = 0.901; p < 0.001). Conclusion 3D fast spin-echo MRI sequence is a reliable and useful technique for determining the location of paraclinoid aneurysms in relation to the cavernous sinus, particularly for patients with no history of SAH.

Abstract 1122‐000060: Endovascular Treatment of Large Intracranial Aneurysms Using Large Volume Coils: Safety and Efficacy

Introduction : Large volume coils in the treatment of intracranial aneurysms have demonstrated better packing density, shorter operative times, less number of coils per aneurysm and better cost‐effectiveness. However, most of the studies evaluated these coils in small or medium sized aneurysms. Therefore, our study aimed to determine our experience using large volume coils in the treatment of large intracranial aneurysms and determine its safety and efficacy. Methods : We retrospectively reviewed consecutive cases of intracranial aneurysms treated with Penumbra Coils 400 (PC400) at our institution between May 2016 and September 2019. Aneurysms > 12 mm in maximal diameter were selected according to the ISUIA trial. Clinical and radiological variables were collected. The modified Rankin Scale (mRS) was used to determine the clinical outcome and was dichotomized (good clinical outcome: mRS £2; poor clinical outcome: mRS >2). The Raymond Roy occlusion classification (RROC) was used to determine obliterations rates. An adequate obliteration was defined as RROC 1 or 2. Categorical variables were expressed as percentages and continuous variables as mean ± standard deviation. Stata v14 software was used for the analysis. Results : Eighteen patients harboring 18 intracranial aneurysms were treated. The mean age was 55 ± 12 years and 14 patients (78%) were women. A good preoperative clinical condition was found in 13 patients (72%). Ten aneurysms were unruptured (56%) and eight were dysplastic (44%). Paraclinoid aneurysms were the most frequently treated (61%). The mean number of coils were 6.2/aneurysm. The mean maximal diameter and neck were 18.9 ± 4.3 mm, and 5.7 ± 2.6 mm, respectively. The mean aspect ratio (AR) was 4 ± 1.9. Coiling was used in 10 cases (56%) followed by stent‐assisted coiling in 7 cases (39%) and balloon‐assisted coiling in 1 case. An immediate adequate obliteration rate was found in 8 cases (44%). Intraoperative complications occurred in two patients in which a coil loop migrated to the parent artery and a stent was placed without clinical consequences. In twelve patients (67%), angiographic follow‐up was performed. The mean follow‐up duration was 9.7 months. Nine patients (75%) showed a complete obliteration (RROC 1), whereas in three patients a residual aneurysm was still present. A good postoperative clinical outcome at discharge was found in 14 patients (78%). Procedure‐related morbidity and mortality were not reported. Conclusions : Embolization with large volume coils is a safe and effective alternative to conventional coils, with high obliteration rates at mid‐term follow‐up. Longer duration of angiographic follow‐up are needed in order to confirm the results presented here.

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.

Case of step-by-step combined treatment of a patient with a ruptured aneurysm of the ophthalmic segment of the internal carotid artery

Aneurysms of the internal carotid artery are the second most common among cerebral aneurysms. When an aneurysm is located in the ophthalmic segment of the internal carotid artery (ICA), the intravascular treatment method is a priority. At the same time, the treatment of recurrent and non-radially switched-off aneurysms of this localization remains a subject of discussion.Case report. We present a 42-year-old patient with a ruptured ICA aneurysm who was admitted in a serious condition. Initially, the patient underwent partial occlusion of the aneurysm cavity with endovascular coiling. In the control cerebral angiography 3 months after the haemorrhage, the recanalization of the aneurysm was verified, which served as an indication for repeated surgical intervention. We preferred the microsurgical method of treatment. A control angiographic study 1 year after the second operation confirmed the radical shutdown of the aneurysm.Discussion. The presented case illustrates the need for a flexible approach in the treatment of complex paraclinoid aneurysms. The choice of endovascular treatment of such aneurysms in the acute period of haemorrhage is justified as the most sparing, although less radical. Depending on the nature of the embolization performed, the timing of the control angiographic examination should be selected individually and can be reduced to 2 months. If there are indications for repeated surgical intervention, it should be performed by the safest method, providing total shutdown of the aneurysm and reducing the volumetric impact of the aneurysm dome on the optic nerve.

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

Background Paraclinoid 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. Methods We 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. Conclusion Proximal 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.

Simpson Grade I Resection of Type II Clinoidal Meningiomal Through Cranio-orbital Zygomatic Approach: 2-Dimensional Operative Video

Clinoidal meningiomas have been considered as a separate entity with distinguishing clinical, radiological, and surgical considerations.1–2 Surgical mortality and morbidity associated with anterior clinoidal meningiomas has remained high in the past, with radical resection considered unattainable.3 However, the extent of surgical removal is clearly the most determining factor in tumor recurrence and progression. Clinoidal meningiomas have been classified into 3 types according to their origin from the dura surface of the anterior clinoid and subsequent arachnoidal rearrangement around the parasellar neurovascular structures.1 In type II, there is an arachnoidal plane that allows the tumor dissection from the encased carotid artery and its branches and the optic nerve. In this type, the involvement of the cavernous sinus is limited to the external wall, which can also be removed. Hence, these tumors are amenable to Simpson grade I resection (tumor, dura, and bone). Approaching through the multidirectional axis provided by the cranio-orbital zygomatic approach allows safe exposure of the tumor and vascular control.4-5 Proximal carotid control is obtained in the petrous carotid canal, the invaded anterior clinoid is removed by and large extradurally, and the Sylvian fissure is split wide open to establish dissecting planes with the middle cerebral artery branches. The optic canal is opened, and tumor extension is removed.6 The invaded outer wall of the cavernous sinus and superior orbital fissure is removed. We demonstrate this technique in a 48-yr-old patient who consented for surgery and publication of images. All images at 2:27, center and right images at 2:46, and all images at 2:58, reused with permission from LWW, from Al-Mefty, Operative Atlas of Meningiomas. Left image at 2:46 reprinted from Surg Neurol, Vol 60/issue 6, Arnautović KI, Al-Mefty O, Angtuaco E, A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms, pp. 504–520, Copyright 1998, with permission from Elsevier. Image at 8:21 reprinted from Al-Mefty,1 Clinoidal meningiomas, by permission from JNSPG.

Microcatheter Stabilization Technique Using Partially Inflated Balloon for Coil Embolization of Paraclinoid Aneurysms

Purpose: Coil embolization of paraclinoid aneurysms should be simple, safe, and effective considering the benign nature of the aneurysm. Here, we present a microcatheter stabilization technique using a partially inflated balloon for the treatment of paraclinoid aneurysms.Materials and Methods: This retrospective study included 58 patients who underwent balloon-assisted coiling (BAC) for unruptured paraclinoid aneurysms at a tertiary neuro-intervention center between January 2019 and March 2020. We applied a technique to stabilize the microcatheter’s position using the modified BAC technique in paraclinoid aneurysms showing various projections around the ophthalmic curve of the internal carotid artery. The basic concept of the technique is to place a partially inflated balloon just distal to the aneurysm neck and support the distal curve of the microcatheter using the proximal bottom of the balloon. Immediate radiological outcomes were analyzed, and clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.Results: The BAC was successfully performed in 51 of 58 patients (88%). We treated the remaining seven patients by switching to stent-assisted coiling. We obtained a 37% mean packing density resulting in favorable occlusion in all 58 aneurysms (complete occlusion in 35 and residual neck in 23). There were no intraprocedural thromboembolic or hemorrhagic events except one that revealed an asymptomatic infarction after the procedure (1.7%). Magnetic resonance angiography follow-up was performed in 37 patients at an average of 11.8 months, in which 11 minor recurrences (29.7%) were found. There was no major recurrence nor retreatment. The mRS score was 0 in all patients during a mean follow-up of 17.7 months (range, 12–25 months).Conclusion: The modified balloon-assisted coiling technique using a partially inflated balloon was safe and effective and could serve as an option for treating paraclinoid aneurysms.

Direct Clipping of Paraclinoid Aneurysm in Conjunction with Extradural Anterior Clinoidectomy: Technical Nuance and Functional Outcome

Objective Because of their anatomical features, treatment for paraclinoid aneurysms has remained to be challenging. Thus, the aim of this report is to prove the validity of our surgical method for unruptured paraclinoid aneurysms, together with surgical videos. Study Design Between August 2017 and November 2019, we were able to perform surgical clipping for 11 patients with unruptured paraclinoid aneurysm using a completely unified method. This study investigated the effect of surgery on multiple measures, including visual impairment, brain contusion, temporalis muscle atrophy, and multiple neurocognitive functions. Results Of the 67 unruptured aneurysms treated at our hospital, 17 were identified to be paraclinoid aneurysm, and 11 of them were treated by direct clipping using anterior clinoidectomy. Three were ophthalmic artery aneurysms, three were superior hypophyseal artery aneurysms, and five were anterior carotid wall aneurysms without branch projection. Only one patient had asymptomatic mild enlargement of the Marriott blind spots postoperatively. No brain contusion and temporalis muscle atrophy were observed in any cases. Only the Trail Making test (TMT) showed a significant worsening in the acute postoperative period: mean pre- and postoperative TMT scores were 59.1 ± 29.1 and 72.7 ± 37.3 for Part A (p = 0.018) and 80.5 ± 35.5 and 93.8 ± 39.9 for Part B (p = 0.030), respectively. However, it improved in the chronic phase. Conclusion We can conclude that our surgical method is safe and can be considered an acceptable treatment. Although surgical stress can cause temporary executive dysfunction shortly after surgery, this decline is temporary.

Unruptured Paraclinoid Carotid Aneurysms Occur More Frequently in Younger Ages

Purpose: We investigated the age distribution of cerebral saccular aneurysms in various locations to clarify the differences by location and discuss the mechanism of formation.Materials and Methods: We retrospectively assessed clinical material obtained from 1,252 unruptured aneurysms treated with endovascular embolization between 2004 and 2019. Age, sex, laterality, and size were investigated by the location of aneurysms, classified as cavernous internal carotid artery (ICA), paraclinoid ICA, supraclinoid ICA, anterior communicating artery, anterior cerebral artery, middle cerebral artery, basilar artery complex, and posterior inferior cerebellar artery. Paraclinoid aneurysms were subclassified into 3 patterns according to their projecting direction: S-type, with superior protrusion; M-type, with medial protrusion; and P-type, with posteroinferior protrusion.Results: There was no significant difference by location for sex, laterality, and size. The mean age of patients with paraclinoid aneurysms (56.5 years old) was significantly lower than that of other aneurysm patients (64.3 years old). Notably, 40% of the patients with M-type aneurysms were <50 years old. This percentage was significantly higher than that of aneurysms at other locations (P<0.05).Conclusion: We found a young female predominance for patients with paraclinoid carotid aneurysms. This study may suggest that congenital factors contribute to paraclinoid aneurysm formation as well acquired factors, such as hemodynamic stress, atherosclerotic wall damage, and local inflammation.