Surgical nuances of giant paraclinoid aneurysms

The Intersection Between the Oculomotor Nerve and the Internal Carotid Artery to Distinguish Extracavernous and Intracavernous Paraclinoid Aneurysms Using Anatomic Dissections-A New 3T Magnetic Resonance Imaging Protocol Confirmed by Three-Dimensionally Printed Biomodels

OBJECTIVE

To evaluate the relationship between the oculomotor nerve (CNIII) and the internal carotid artery (ICA) as a new anatomic-radiologic landmark for distinguishing the exact location of a paraclinoid intracranial aneurysm (IA).

METHODS

Microanatomic dissections were performed in 20 cavernous sinuses to evaluate the ICA paraclinoid region. Based on anatomic observations, a new magnetic resonance (MRI) protocol to classify paraclinoid aneurysms was proposed. MRI of 42 IAs from 34 patients was independently analyzed and classified as intracavernous, extracavernous, or transitional by 2 neuroradiologists. To validate the proposed MRI protocol, each IA was classified by a three-dimensionally (3D) printed biomodel and agreement with the radiologic classifications was evaluated. Of 42 IAs, 23 undergoing microsurgeries were also classified by direct visualization.

RESULTS

We observed that the true cavernous sinus roof is defined by the carotid-oculomotor membrane, which has an intimate relationship with the intersection between the superior limit of the CNIII and the ICA. Based on this intersection, all 42 IAs were radiologically classified and agreement with the 3D printed biomodels was observed in 95% IAs. Concordance tests showed a statistically significant (P < 0.05) agreement between the classifications. All 23 IAs treated had the radiologic and 3D biomodel classification confirmed.

CONCLUSIONS

The intersection between the ICA and the CNIII, which crosses it transversely in its entire diameter, is a reliable anatomic-radiologic landmark to correctly classify paraclinoid aneurysms. Through a new MRI protocol, it is possible to radiologically identify this intersection and to easily distinguish the intracavernous and extracavernous ICA paraclinoid aneurysms.

Endoscopic Endonasal Supraoptic and Infraoptic Approaches for Complex "Parasuprasellar" Lesions: Surgical Anatomy, Technique Nuances, and Case Series

Objective

The surgical management of lesions involving the lateral area of the suprasellar region, including the lateral aspect of the planum sphenoidale and the tight junction region of the optic canal (OC), anterior clinoid process (ACP), and internal carotid artery (ICA) and its dural rings, is extremely challenging. Here, these regions, namely, the “parasuprasellar” area, are described from the endonasal perspective. Moreover, the authors introduce two novels endoscopic endonasal supraoptic (EESO) and endoscopic endonasal infraoptic (EEIO) approaches to access the parasuprasellar area.

Methods

Surgical simulation of the EESO and EEIO approaches to the parasuprasellar area was conducted in 5 silicon-injected specimens. The same techniques were applied in 12 patients with lesions involving the parasuprasellar area.

Results

The EESO approach provided excellent surgical access to the lateral region of the planum sphenoidale, which corresponds to the orbital gyrus of the frontal lobe. With stepwise bone (OC, optic strut and ACP) removal, dissociation of the ophthalmic artery (OA) and optic nerve (ON), the EEIO approach enables access to the lateral region of the supraclinoidal ICA. These approaches can be used independently or in combination, but are more often employed as a complement to the endoscopic endonasal midline and transcavernous approaches. In clinical application, the EESO and EEIO approaches were successfully performed in 12 patients harboring tumors as well as multiple aneurysms involving the parasuprasellar area. Gross total and subtotal tumor resection were achieved in 9 patients and 1 patient, respectively. For two patients with multiple aneurysms, the lesions were clipped selectively according to location and size. Visual acuity improved in 7 patients, remained stable in 4, and deteriorated in only 1. No postoperative intracranial infection or ICA injury occurred in this series.

Conclusions

The EESO and EEIO approaches offer original treatment options for well-selected lesions involving the parasuprasellar area. They can be combined with the endoscopic endonasal midline and transcavernous approaches to remove extensive pathologies involving the intrasellar, suprasellar, sphenoid, and cavernous sinuses and even the bifurcation of the ICA. This work for the first time pushes the boundary of the endoscopic endonasal approach lateral to the supraclinoidal ICA and ON.

Limited Indications for Clipping Surgery of Paraclinoid Aneurysm Based on Long-Term Visual Morbidity

OBJECTIVE

Clipping of paraclinoid aneurysm is still challenging because of poor visual morbidity. The extradural temporopolar approach was applied to clip paraclinoid aneurysms, with the expectation of reducing visual morbidity. Factors related to poor visual morbidity were evaluated, to assess the results for clipping of paraclinoid aneurysms.

METHODS

A series of 40 unruptured paraclinoid aneurysms in 38 patients were clipped via extradural temporopolar approach. Preoperative and postoperative states of visual cognitive function and radiological outcomes were investigated. Aneurysms were classified into dorsal type or non-dorsal type, and small (<9 mm) or not-small (≥9 mm), respectively, to identify factors correlated with visual morbidity.

RESULTS

Complete clipping rate was 90.0% without any recurrence (mean: 5.2 years). Visual morbidity was unexpectedly high at 28.9%, including 2.7% of blindness immediately after the operation, and 23.7% and 2.7% at the final examination (mean: 3.6 years). Multivariate analysis showed aneurysm size was significantly correlated with worse visual outcome. Visual morbidity was 13.3% and 11.1% for dorsal and the non-dorsal small aneurysms, respectively, and all these cases showed visual field defect limited to the nasal quadrant without decreased visual acuity. In contrast, the non-dorsal not-small aneurysms showed significantly worse visual morbidity (60%) with decreased visual acuity.

CONCLUSIONS

Clipping via extradural temporopolar approach can achieve durable treatment for small unruptured paraclinoid aneurysms with acceptable visual morbidity. Visual morbidity of the not-small non-dorsal type, however, was poor. The indications for clipping of paraclinoid aneurysm should be limited to small aneurysms, especially the dorsal type in young patients.

Cavernous carotid artery aneurysms on a single institution: An epidemiological study with 201 patients

OBJECTIVES

Cavernous carotid aneurysms (CCA) represent 2-9% of all intracranial aneurysms. For long considered benign lesions, these entities are unique when it comes to clinical presentation and management. Usually asymptomatic, CCAs can grow and rupture causing different manifestations. The lack of a long-term assessment of both treated and untreated CCAs' natural history justifies why there is no consensus regarding what are the recommended therapeutic measures. While some advocate that an intervention is always necessary, others consider that patients deserve an individualized evaluation.

PATIENTS AND METHODS

We describe our single-institution experience in diagnosis, follow-up, and management of 201 CCAs. In addition, we evaluate the association of giant CCAs with aneurysms in other locations using a Chi-square test.

RESULTS

201 patients had 245 CCAs. 92% of the patients were women. The mean age at diagnosis was 61 years. Concomitant aneurysms were observed in 53.2% of the patients, and the middle cerebral artery was the most affected artery. 66 (30.6%) CCAs were considered "giant", and the follow-up period ranged from 1 to 23 years.The presence of a giant CCA seemed to hinder other aneurysms' formation - RR 0.47 (IC 95% 0.31-0.67), p < 0.0001.

CONCLUSIONS

CCAs should be individually assessed. A conservative approach ought to be adopted for asymptomatic and oligosymptomatic lesions. Finally, a multidisciplinary team must evaluate the other situations, in order to define whether the microsurgical or the endovascular treatment is better option. Presence of a giant lesion within the cavernous sinus is associated with less occurrence of other aneurysms.

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 79 years. Aneurysm size mainly varied between 2 and 10 mm 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.

Entire Orifice Blocking-Assisted Microsurgical Treatment: Clipping of Intracranial Giant Wide-Neck Paraclinoid Aneurysms

OBJECTIVE

Giant wide-neck paraclinoid aneurysms remain a formidable challenge for neurosurgeons due to the brisk retrograde blood flow during surgical clipping. Theoretically, Entire orifice blockade (EOB) by placing a longitudinal intracarotid balloon catheter across the aneurysm neck could achieve a good vascular control in treating cerebral aneurysms, but related studies have been scarce. The aim of this study was to evaluate the safety and efficiency of the EOB-assisted microsurgical technique for treating giant wide-neck paraclinoid aneurysms.

METHODS

Clinical data and treatment summaries of patients with giant wide-neck paraclinoid aneurysms who underwent EOB-assisted microsurgical clipping were retrospectively reviewed.

RESULTS

A total of 26 patients were analyzed. All but 3 patients harbored unruptured aneurysms. The mean largest diameter of the aneurysms was 26.8±2.0 mm, and the mean neck size was 12.5±2.4 mm. All lesions were successfully clipped without residual aneurysms. Post-operative images revealed no major branch occlusion due to thromboembolic complications. Four patients presented neurologic deficits caused by vasospasm, 3 of which were completely resolved by postoperative treatment. At a mean follow-up time of 1.86 ± 0.95 years (range, 0.5-3.5 years), none of the patients died, and 96.2% (n = 25) of the patients had favorable clinical outcomes with modified Rankin Scale values of 0-2.

CONCLUSIONS

For patients with giant wide-neck paraclinoid aneurysms, EOB-assisted microsurgical clipping is a safe and useful procedure for obtaining vascular control, for softening and shrinking the aneurysm sac and for providing a wide and clean operative field that allows the clip to be effectively placed.

Challenges in a case of ophthalmic artery aneurysm associated with abnormal internal carotid arteries

Ophthalmic artery aneurysms account for 5% of all cerebral aneurysms and are an important cause of morbidity and mortality related to subarachnoid hemorrhage. The diagnosis is often made only when the aneurysm is large enough to become symptomatic. They remain technically challenging for both neurosurgeon and interventional radiologist. We present the case of a 62-year-old woman admitted for transient loss of consciousness, followed by generalized tonic-clonic seizures. Computed tomography (CT) showed a subarachnoid hemorrhage (SAH), clinically graded as Hunt and Hess III. Magnetic resonance imaging (angioMR) and the four-vessel digital subtraction angiography (DSA) identified a ruptured, 8 mm left ophthalmic artery aneurysm. Embolization was the first therapeutic choice. Nevertheless, the attempt had to be aborted due to a combination of a hypoplastic right internal carotid artery (ICA) and an irregular atheromatous plaque on the left ICA, rendering the procedure unduly hazardous. Therefore, microsurgical clipping of the aneurysm became the procedure of choice. Postoperatively, the patient was in good condition, with no visual and neurological deficits. At 6 months follow up, she was assigned maximum scores of 5 and 8 on the Glasgow Outcome Scale (GOS) and Extended GOS (GOS-E), respectively. Aneurysm rupture represents a neurosurgical emergency and an early intervention (less than 48 h) is recommended to maximize the chances of deficit-free survival. The peculiarities of this case consisted in the combination between the size and the location of the aneurysm, abrupt presentation, and the impossibility of embolization due to bilateral ICA abnormalities, congenital (hypoplastic right ICA) and acquired (extensively atherosclerotic left ICA).

Surgical Treatment of 127 Paraclinoid Aneurysms with Multifarious Strategy: Factors Related with Outcome

BACKGROUND

Few reports have been published discussing surgical outcomes of paraclinoid aneurysms using multifarious treatments such as high-flow bypass.

MATERIAL AND METHODS

We retrospectively analyzed findings from 127 consecutive patients (19 males, mean age at surgery: 56.8 years, range: 19-81 years) at our hospital. The size of aneurysms ranged from 2.7-43.2 mm (mean: 6.9 mm). Extradural anterior clinoidectomy was used to clip small aneurysms. As large or giant aneurysms required a longer temporal occlusion period and often could not undergo simple clipping, high-flow bypass with anterior clinoidectomy or cervical internal carotid ligation was performed to reduce aneurysm blood flow and induce thrombosis. We reviewed a postoperative modified Rankin Scale (mRS), radiographic outcomes, cerebral infarction, and visual disturbance. In addition, we analyzed factors relating to the outcomes and complications, with focus on the aneurysm size, location, and type of surgical treatment.

RESULTS

Good outcomes were achieved in all patients, as follows: mRS 0:100, mRS 1:16, mRS 2:11, and mRS 3-6:0. Among the 127 patients, complete exclusion of aneurysm was achieved in 119 cases (93.7%). Postoperative morbidity included ischemic lesions in 11 (8.6%) and visual disturbance in 24 (18.8%). Significant statistical differences were observed between ischemic complication and aneurysm size and location (P = 0.0001) and surgical treatment (P < 0.0001).

CONCLUSION

Surgical treatment of unruptured paraclinoid aneurysm has high efficacy with good outcomes and a high rate of complete exclusion. However, the rate of visual disturbance is relatively high. Careful surgical techniques and intraoperative monitoring are therefore required.

Cavernous carotid artery aneurysms: epidemiology, natural history, diagnostic and treatment. An experience of a single institution

BACKGROUND

Cavernous carotid aneurysms (CCA) account for 2-9% of all intracranial aneurysms. They have been considered benign lesions, most often asymptomatic, and to have a natural history with a low risk of life-threatening complications. These aneurysms are unique, their rupture can present in many different forms, they can suffer spontaneous thrombotic changes and the symptomatology related to the mass effect involves the neuro-ophthalmologic system. In this scenario the natural history and clinical presentation are largely different from other intracranial aneurysms. Some investigators advocate treatment of both symptomatic and asymptomatic CCAs, others recommend no treatment. The reason for this controversy relates to a lack of information on the long term natural history of these aneurysms, as well as on the long term results of treatment.

METHODS

In this article the authors discuss their single institution experience in diagnosis, natural history and management of 123 asymptomatic and oligosympotomatic aneurysms located in the cavernous portion of internal carotid artery.

CONCLUSIONS

According to our results asymptomatic or olygosymptomatic (pain) CCAs should be conservatively managed with serial images while the others presentations should be analyzed by a multidisciplinary team, involving the neuroendovascular and microsurgical services.

French collaborative group series on giant intracranial aneurysms: Current management

OBJECTIVES

Giant intracranial aneurysms represent a major therapeutic challenge for each surgical team. The aim of our study was to extensively review the French contemporary experience in treating giant intracranial aneurysms in order to assess the current management.

PATIENTS AND METHODS

This retrospective multicenter study concerned consecutive patients treated for giant intracranial aneurysms (2004-2008) in different French university hospitals (Bordeaux, Caen, Clermont-Ferrand, Lille, Lyon, Nice, Paris-Lariboisière, Rouen et Toulouse). Different variables were analyzed: the diagnostic circumstances, the initial clinical status based on the WFNS scale, aneurysmal features and exclusion procedure. At 6 months, the outcome was evaluated according to the modified Rankin Scale (mRS): favorable (mRS 0-2) and unfavorable (mRS 3-6). A multivariate logistic regression model included all the independent variables with P<0.25 in the univariate analysis (P<0.05).

RESULTS

A total of 79 patients with a mean age of 51.5 ± 1.6 years (median: 52 years; range: 16-79) were divided into two groups, with the ruptured group (n=26, 32.9%) significantly younger (P<0.05, Student's-t-test) than the unruptured group (n=53, 67.1%). After SAH, the initial clinical status was good in 12 patients (46.2%), and in the unruptured group, the predominant diagnosis circumstance was a pseudo-tumor syndrome occurring in 22 (41.5%). The first procedure of aneurysm treatment in the global population was endovascular in 42 patients (53.1%), microsurgical in 29 (36.7%) and conservative in 8 (10.2). An immediate neurological deterioration was reported in 38 patients (48.1%) after endovascular treatment in 19 (45.2% of endovascular procedures), after miscrosurgical in 15 (51.7% of microsurgical procedures) and after conservative in 4 (the half). At 6 months, the outcome was favorable in 45 patients (57%) and after multivariate analysis, the predictive factors of favorable outcome after management of giant cerebral aneurysm were the initial good clinical status in cases of SAH (P<0.002), the endovascular treatment (P<0.005), and the absence of neurological deterioration (P<0.006). The endovascular procedure was obtained as a predictive factor because of the low risk efficacy of indirect procedures, in particular a parent vessel occlusion.

CONCLUSION

The overall favorable outcome rate concerned 57% of patients at 6 months despite 53.8% of poor initial clinical status in cases of rupture. The predictive factors for favorable outcome were good clinical status, endovascular treatment and the absence of postoperative neurological deterioration. Endovascular treatment should be integrated into the therapeutic armenmatarium against giant cerebral aneurysms but the durability of exclusion should be taken into account during the multidisciplinary discussion by the neurovascular team.

Internal carotid artery reconstruction using multiple fenestrated clips for complete occlusion of large paraclinoid aneurysms

Objective

Although surgical techniques for clipping paraclinoid aneurysms have evolved significantly in recent times, direct microsurgical clipping of large and giant paraclinoid aneurysms remains a formidable surgical challenge. We review here our surgical experiences in direct surgical clipping of large and giant paraclinoid aneurysms, especially in dealing with anterior clinoidectomy, distal dural ring resection, optic canal unroofing, clipping techniques, and surgical complications.

Methods

Between September 2001 and February 2012, we directly obliterated ten large and giant paraclinoid aneurysms. In all cases, tailored orbito-zygomatic craniotomies with extradural and/or intradural clinoidectomy were performed. The efficacy of surgical clipping was evaluated with postoperative digital subtraction angiography and computed tomographic angiography.

Results

Of the ten cases reported, five each were of ruptured and unruptured aneurysms. Five aneurysms occurred in the carotid cave, two in the superior hypophyseal artery, two in the intracavernous, and one in the posterior wall. The mean diameter of the aneurysms sac was 18.8 mm in the greatest dimension. All large and giant paraclinoid aneurysms were obliterated with direct neck clipping without bypass. With the exception of the one intracavenous aneurysm, all large and giant paraclinoid aneurysms were occluded completely.

Conclusion

The key features of successful surgical clipping of large and giant paraclinoid aneurysms include enhancing exposure of proximal neck of aneurysms, establishing proximal control, and completely obliterating aneurysms with minimal manipulation of the optic nerve. Our results suggest that internal carotid artery reconstruction using multiple fenestrated clips without bypass may potentially achieve complete occlusion of large paraclinoid aneurysms.

Exclusively intradural exposure and clip reconstruction in complex paraclinoid aneurysms

BACKGROUND

The management of complex paraclinoid aneurysms is still challenging. In this article we describe our approach to paraclinoid aneurysms, which has evolved over several years, using an exclusively intradural approach.

METHOD

All procedures are done under continuous electrophysiological monitoring. A standard pterional approach is used to access the paraclinoid region exclusively intraduraly. After optic nerve unroofing and tailored clinoidectomy, the aneurysm neck is visualized and clipped using the tandem clipping technique and suction decompression if necessary. Aneurysm occlusion is verified using intraoperative ICG angiography and postoperative 3D DSA.

CONCLUSION

The exclusively intradural approach to complex paraclinoid aneurysms with tailored clinoidectomy offers an excellent surgical corridor for the treatment of these challenging lesions.

Microneurosurgical Management of Ophthalmic Segment of the Internal Carotid Artery Aneurysms

BACKGROUND:

Surgical clipping of ophthalmic segment aneurysms is more technically challenging than other anterior circulation aneurysms.

OBJECTIVE:

To analyze whether surgical clipping is an effective treatment for ophthalmic segment aneurysms with good clinical outcomes and acceptable complication rates.

METHODS:

From 1994 to 2009, a total of 86 aneurysms of the ophthalmic segment of the internal carotid artery were surgically clipped in 80 patients. We retrospectively reviewed the records of these patients to analyze the clinical outcome.

RESULTS:

Of the 86 aneurysms, 68 (79%) were large or giant. Cranial base modification was required in 28 operations. Drilling of the anterior clinoid process was performed in 49 operations. The mean follow-up was 27.38 months. Of the 80 patients, 76 were assessable for clinical outcome. At the last follow-up, 5 patients had a Glasgow Outcome Scale (GOS) score of 1, 4 had a GOS score of 3, 10 had a GOS score of 4, and 57 had a GOS score of 5. Thus, the clinical outcome was good (GOS scores of 5 and 4) in the majority (88%) of patients. Of the 15 patients who presented with visual problems before surgery, 77% showed improvement after surgical clipping. The overall visual morbidity rate was 2.5%. Outcome assessment indicated that infarcts (P = .000), hydrocephalus (P = .001), and poor grade (P = .000) were significant negative predictors of outcome.

CONCLUSION:

Surgical clipping is an effective treatment for ophthalmic segment of the internal carotid artery aneurysms with excellent or good clinical outcome. Infarcts, hydrocephalus, and poor grade were significant negative predictors of outcome. Surgical clipping may facilitate improvement in vision by decompression of the visual apparatus.