Surgery for paraclinoidal carotid artery aneurysms

Superior hypophyseal artery aneurysm: microsurgical vs. endovascular treatment

This study aimed to provide an updated evidence of superior hypophyseal artery (SHA) aneurysms management, including their clinical implications, predictive factors for rupture, therapeutic approaches, and post-treatment outcomes. This systematic review and meta-analysis, following PRISMA guidelines, assessed the literature on superior hypophyseal artery aneurysms. Studies were selected based on predefined criteria, focusing on coiling and clipping interventions. Data were extracted and analyzed using SPSS and Cochrane RevMan, with assessments of heterogeneity, sensitivity, and publication bias. Study quality was evaluated using the Newcastle-Ottawa Scale and RoB2. A total of 20 studies involving 316 patients were included. The clipping group had a mean age of 53.8 years, while the coiling group had 50.3 years. Most aneurysms were smaller than 7 mm. Aneurysm remnants occurred in 1.1% after clipping and 2.8% after coiling. Clipping was associated with lower recurrence rates (0% vs. 9.3%) and fewer visual disturbances and vasospasms. Mortality was equal (1%) for both groups. The coiling group had better outcomes on the modified Rankin Scale (94% vs. 73% for clipping). Meta-analysis confirmed that clipping had better recurrence and functional outcomes, with no significant differences in aneurysm size or mortality. Surgical clipping is a viable treatment for SHA aneurysms but carries risks, while coil embolization offers a safer, effective alternative. Early intervention, especially for larger aneurysms (> 7 mm), is crucial to prevent rupture. Future research should focus on personalized treatment strategies, as this study's small sample size and study limitations warrant further investigation.

Contralateral vs. Ipsilateral Approach to Superior Hypophyseal Artery Aneurysms: An Anatomical Study and Morphometric Analysis

Introduction

Surgical clipping of superior hypophyseal artery (SHA) aneurysms is a challenging task for neurosurgeons due to their close anatomical relationships. The development of endovascular techniques and the difficulty in surgery have led to a decrease in the number of surgical procedures and thus the experience of neurosurgeons in this region. In this study, we aimed to reveal the microsurgical anatomy of the ipsilateral and contralateral approaches to SHA aneurysms and define their limitations via morphometric analyses of radiological anatomy, three-dimensional (3D) modeling, and surgical illustrations.

Method

Five fixed and injected cadaver heads underwent dissections. In order to make morphometric measurements, 75 cranial MRI scans were reviewed. Cranial scans were rendered with a module and used to produce 3D models of different anatomical structures. In addition, a medical illustration was drawn that shows different sizes of aneurysms and surgical clipping approaches.

Results

For the contralateral approach, pterional craniotomy and sylvian dissection were performed. The contralateral SHA was reached from the prechiasmatic area. The dissected SHA was approached with an aneurysm clip, and maneuverability was evaluated. For the ipsilateral approach, pterional craniotomy and sylvian dissection were performed. The ipsilateral SHA was reached by mobilizing the left optic nerve with left optic nerve unroofing and left anterior clinoidectomy. MRI measurements showed that the area of the prechiasm was 90.4 ± 36.6 mm² (prefixed: 46.9 ± 10.4 mm², normofixed: 84.8 ± 15.7 mm², postfixed: 137.2 ± 19.5 mm², p < 0.001), the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale was 10.0 ± 3.5 mm (prefixed: 5.7 ± 0.8 mm, normofixed: 9.6 ± 1.6 mm, postfixed:14.4 ± 1.6 mm, p < 0.001), and optic nerves’ interneural angle was 65.2° ± 10.0° (prefixed: 77.1° ± 7.3, normofixed: 63.6° ± 7.7°, postfixed: 57.7° ± 5.7°, p: 0.010).

Conclusion

Anatomic dissections along with 3D virtual model simulations and illustrations demonstrated that the contralateral approach would potentially allow for proximal control and neck control/clipping in smaller SHA aneurysm with relatively minimal retraction of the contralateral optic nerve in the setting of pre- or normofixed chiasm, and ipsilateral approach requires anterior clinodectomy and optic unroofing with considerable optic nerve mobilization to control proximal ICA and clip the aneurysm neck effectively.

Ophthalmic Segment Aneurysms: Surgical Treatment and Outcomes

Background  Surgical treatment of ophthalmic segment aneurysms (OSAs) remain challenging because of complex anatomy surrounding the aneurysm and entails extensive drilling of anterior clinoid process to define proximal neck of the aneurysm and carotid exposure in the neck for proximal control. Materials and Methods  Authors present a retrospective analysis of 36 aneurysms in 35 patients with OSAs operated surgically by first author. Surgical clipping was done for the aneurysms as primary modality of treatment along with wrapping and trapping as required. Results  Commonest age group was 40 to 60 years with female preponderance of 3:1. Maximum (23) patients presented with subarachnoid hemorrhage (WFNS Gr 1), followed by asymptomatic patients (six). There were 18 small, 14 large, and four giant aneurysms, 15 dorsal wall, 17 ventral wall, three proximal posterior wall, and one blister aneurysm. Good outcome, as measured by Glasgow Outcome Score (GOS) was achieved in 29 patients. Conclusion  OSAs are technically demanding aneurysms, but with due diligence to surgical principles, good outcomes may be obtained.

Comparative Analysis of Feasibility of the Retrograde Suction Decompression Technique for Microsurgical Treatment of Large and Giant Internal Carotid Artery Aneurysms

Objective

Retrograde suction decompression (RSD) is an adjuvant technique used for the microsurgical treatment of large and giant internal carotid artery (ICA) aneurysms. In this study, we analyzed the efficacy and safety of the RSD technique for the treatment of large and giant ICA aneurysms relative to other conventional microsurgical techniques.

Methods

The aneurysms were classified into two groups depending on whether the RSD method was used (21 in the RSD group vs. 43 in the non-RSD group). Baseline characteristics, details of the surgical procedure, angiographic outcomes, clinical outcomes, and procedure-related complications of each group were reviewed retrospectively.

Results

There was no significant difference in the rates of complete neck-clipping between the RSD (57.1%) and non-RSD (67.4%) groups. Similarly, there was no difference in the rates of good clinical outcomes (modified Rankin Scale score, 0–2) between the RSD (85.7%) and non-RSD (81.4%) groups. Considering the initial functional status, 19 of 21 (90.5%) patients in the RSD group and 35 of 43 (81.4%) patients in the non-RSD group showed an improvement or no change in functional status, which did not reach statistical significance.

Conclusion

In this study, the microsurgical treatment of large and giant intracranial ICA aneurysms using the RSD technique obtained competitive angiographic and clinical outcomes without increasing the risk of procedure-related complications. The RSD technique might be a useful technical option for the microsurgical treatment of large and giant intracranial ICA aneurysms.

Microsurgical Clipping Techniques and Outcomes for Paraclinoid Internal Carotid Artery Aneurysms

BACKGROUND

Microsurgical clipping of paraclinoid aneurysms presents unique technical challenges because of the anatomical complexity of the paraclinoid region.

OBJECTIVE

To analyze microsurgical clipping techniques, complications, and outcomes associated with paraclinoid aneurysms, with a focus on clip selection and clipping technique according to aneurysm location.

METHODS

From 1997 to 2016, 231 unruptured paraclinoid aneurysms from 216 patients were treated using microsurgical clipping. We retrospectively reviewed patient records to analyze clinical outcomes.

RESULTS

A total of 80 aneurysms (34.6%) were treated with simple clipping. Among them, fenestrated clips were used with superior hypophyseal artery (SHA) aneurysms, but curved clips were used with most other aneurysms. A total of 151 aneurysms (65.6%) were treated using multiple clips, including tandem clipping for ophthalmic artery (OphA) aneurysms, tandem angled-fenestrated clipping for SHA and ventral carotid aneurysms, stacked clipping for dorsal carotid aneurysms, and various techniques for clinoidal segment/carotid cave aneurysms. Postoperative angiography was performed in 214 aneurysms (92.6%), and complete obliteration was confirmed in 195 aneurysms (91.1%). Using the modified Rankin Scale (mRS), overall functional outcome was good (mRS 0-2) in 99.6% of patients, although 30 cases (13.0%) showed new postoperative visual deficits.

CONCLUSION

Surgical clipping of paraclinoid aneurysms is an excellent treatment modality with good clinical outcomes and acceptable complication rates, particularly in centers with large experience in the microsurgical management of cerebrovascular disorders. Appropriate clip selection and clipping techniques are required to perform complete and safe clipping.

Endovascular Temporary Balloon Occlusion for Microsurgical Clipping of Posterior Circulation Aneurysms

Based on the relationship between the posterior clinoid process and the basilar artery (BA) apex it may be difficult to obtain proximal control of the BA using temporary clips. Endovascular BA temporary balloon occlusion (TBO) can reduce aneurysm sac pressure, facilitate dissection/clipping, and finally lower the risk of intraoperative rupture. We present our experience with TBO during aneurysm clipping of posterior circulation aneurysms within the setting of a hybrid operating room (hOR). We report one case each of a basilar tip, posterior cerebral artery, and superior cerebellar artery aneurysm that underwent surgical occlusion under TBO within an hOR. Surgical exposure of the BA was achieved with a pterional approach and selective anterior and posterior clinoidectomy. Intraoperative digital subtraction angiography (iDSA) was performed prior, during, and after aneurysm occlusion. Two patients presented with subarachnoid hemorrhage and one patient presented with an unruptured aneurysm. The intraluminal balloon was inserted through the femoral artery and inflated in the BA after craniotomy to allow further dissection of the parent vessel and branches needed for the preparation of the aneurysm neck. No complications during balloon inflation and aneurysm dissection occurred. Intraoperative aneurysm rupture prior to clipping did not occur. The duration of TBO varied between 9 and 11 min. Small neck aneurysm remnants were present in two cases (BA and PCA). Two patients recovered well with a GOS 5 after surgery and one patient died due to complications unrelated to surgery. Intraoperative TBO within the hOR is a feasible and safe procedure with no additional morbidity when using a standardized protocol and setting. No relevant side effects or intraoperative complications were present in this series. In addition, iDSA in an hOR facilitates the evaluation of the surgical result and 3D reconstructions provide documentation of potential aneurysm remnants for future follow-up.

Visual Outcomes after Surgery for Paraclinoid Aneurysms: A Fujita Experience

INTRODUCTION

The surgical strategies for clipping of paraclinoid aneurysms are diverse. These aneurysms are unique in their location, as they closely abut the anterior clinoid process (ACP) and the optic nerve. The ultimate goal of clipping encompasses the exposure of neck of the aneurysm which is seldom complete without the manipulation of optic nerve and the ACP. This manipulation may result in disturbances of vision postoperatively. We analyze our results of visual outcomes in the surgery for paraclinoid aneurysms in this retrospective study.

MATERIALS AND METHODS

All patients with paraclinoid aneurysms who underwent surgery from June 2014 to June 2019 were included in the study. Surgical procedure was uniform in all patients which included anterior clinoidectomy and clipping of aneurysms as per the Bantane protocol. Glasgow Outcome Scale as well as vision was assessed at discharge and at 1 month and 6 months.

RESULTS

There were 77 cases of paraclinoid aneurysms operated during the abovementioned period. All patients had no symptoms related to vision preoperatively. Visual deterioration was noted in two patients. All patients were discharged with a good outcome on the Glasgow Outcome Scale.

CONCLUSION

Paraclinoid aneurysm has a good outcome when treated with surgery. The visual deterioration following surgery can be minimized with extradural anterior clinoidectomy and careful handling of the vessels and nerve.

Microsurgical Treatment of Paraclinoid Aneurysms by Extradural Anterior Clinoidectomy: The Fujita Experience

Introduction:

Paraclinoid aneurysms pose technical difficulty in their approach, mainly because of their close proximity to neurovascular structures, deeper location, and a smaller corridor. Extradural anterior clinoidectomy is a highly beneficial technique in such cases, making more space to deal with these aneurysms. We describe our method of performing extradural anterior clinoidectomy in such patients.

Materials and Methods:

A total of 33 cases of paraclinoid internal carotid artery aneurysms presenting to Fujita Health University Banbuntane Hospital, Japan, were included. Females comprised the majority with 32 cases; the mean age was 54.8 years (range: 35–74 years). The mean size of the paraclinoid aneurysm was 5.3 mm (range: 3–12 mm).

Results:

Nine paraclinoid aneurysms were found projecting dorsally, 7 laterally, and 17 medially (Kazuhiko Kyoshim et al's. classification). An immediate complete occlusion rate of 100% was present. Visual disturbance was found in 6.2% of our patients. One of our patients developed permanent loss of vision.

Conclusion:

Extradural anterior clinoidectomy enables a better exposure to paraclinoid aneurysms. Precise anatomical knowledge along with microsurgical tactics is required to prevent and manage potential complications to achieve good outcomes.

A Retrospective Study in Microsurgical Procedures of Large and Giant Intracranial Aneurysms: An Outcome Analysis

OBJECTIVE

Intracranial aneurysms are considered large if >10 mm and giant if >25 mm. The risk of aneurysmal rupture compounds with increase in size of the aneurysm, thus, warranting appropriate intervention. In this study, we have analyzed the outcome and effectiveness of microsurgical procedures in large and giant aneurysms.

METHODS

A retrospective analysis of all the patients who underwent microsurgical procedures for large and giant cerebral aneurysms from 2014-2018 in our institute was conducted. There were a total of 52 patients, in which direct clipping was performed in 42 (80.7%) patients, proximal trapping in 3 (5.7%) patients, trapping with bypass in 3 (5.7%) patients, suction decompression in 3 (5.7%) patients, and 1 (1.9%) patient underwent surgical reconstruction.

RESULTS

Among the 52 patients, in the postoperative period, 1 (1.9%) patient became comatose, 1 (1.9%) patient developed hemiplegia, 1 (1.9%) patient had a transient hemiparesis, and 1 (1.9%) patient had transient lower cranial nerve palsy. Two (3.8%) patients had chronic subdural hematoma during the 3-month follow-up. There was no mortality in our series.

CONCLUSIONS

There are several treatment strategies available to manage large and giant cerebral aneurysms. In this study, we had minimal morbidity (3.8%), favorable outcome (96.1%), and no mortality. Therefore, we would like to conclude that appropriate microsurgical procedures, in experienced hands, can be considered as first line in the management for large and giant intracranial aneurysms, especially those with complex anatomy, wide neck, mass effect, partial thrombosis, and the presence of critical perforating vessels from the aneurysm wall.

The 25th anniversary of the retrograde suction decompression technique (Dallas technique) for the surgical management of paraclinoid aneurysms: historical background, systematic review, and pooled analysis of the literature

OBJECTIVE

Paraclinoid internal carotid artery (ICA) aneurysms frequently require temporary occlusion to facilitate safe clipping. Brisk retrograde flow through the ophthalmic artery and cavernous ICA branches make simple trapping inadequate to soften the aneurysm. The retrograde suction decompression (RSD), or Dallas RSD, technique was described in 1990 in an attempt to overcome some of those treatment limitations. A frequent criticism of the RSD technique is an allegedly high risk of cervical ICA dissection. An endovascular modification was introduced in 1991 (endovascular RSD) but no studies have compared the 2 RSD variations.

METHODS

The authors performed a systematic review of MEDLINE/PubMed and Web of Science and identified all studies from 1990-2016 in which either Dallas RSD or endovascular RSD was used for treatment of paraclinoid aneurysms. A pooled analysis of the data was completed to identify important demographic and treatment-specific variables. The primary outcome measure was defined as successful aneurysm obliteration. Secondary outcome variables were divided into overall and RSD-specific morbidity and mortality rates.

RESULTS

Twenty-six RSD studies met the inclusion criteria (525 patients, 78.9% female). The mean patient age was 53.5 years. Most aneurysms were unruptured (56.6%) and giant (49%). The most common presentations were subarachnoid hemorrhage (43.6%) and vision changes (25.3%). The aneurysm obliteration rate was 95%. The mean temporary occlusion time was 12.7 minutes. Transient or permanent morbidity was seen in 19.9% of the patients. The RSD-specific complication rate was low (1.3%). The overall mortality rate was 4.2%, with 2 deaths (0.4%) attributable to the RSD technique itself. Good or fair outcome were reported in 90.7% of the patients.Aneurysm obliteration rates were similar in the 2 subgroups (Dallas RSD 94.3%, endovascular RSD 96.3%, p = 0.33). Despite a higher frequency of complex (giant or ruptured) aneurysms, Dallas RSD was associated with lower RSD-related morbidity (0.6% vs 2.9%, p = 0.03), compared with the endovascular RSD subgroup. There was a trend toward higher mortality in the endovascular RSD subgroup (6.4% vs 3.1%, p = 0.08). The proportion of patients with poor neurological outcome at last follow-up was significantly higher in the endovascular RSD group (15.4% vs 7.2%, p < 0.01).

CONCLUSIONS

The treatment of paraclinoid ICA aneurysms using the RSD technique is associated with high aneurysm obliteration rates, good long-term neurological outcome, and low RSD-related morbidity and mortality. Review of the RSD literature showed no evidence of a higher complication rate associated with the Dallas technique compared with similar endovascular methods. On a subgroup analysis of Dallas RSD and endovascular RSD, both groups achieved similar obliteration rates, but a lower RSD-related morbidity was seen in the Dallas technique subgroup. Twenty-five years after its initial publication, RSD remains a useful neurosurgical technique for the management of large and giant paraclinoid aneurysms.

Comparison between frontolateral approach and pterional approach in the surgical treatment of paraclinoid aneurysms

OBJECTIVE

To compare the pterional and frontolateral approach to determine the most effective route for paraclinoid aneurysm surgery.

METHODS

Between June 2010 and December 2015, a total of 176 patients with paraclinoid aneurysm underwent surgical clipping, 96 through the pterional and 80 through the frontolateral approach. We analyzed the two groups and compared demographic, radiologic, and clinical variables including age, sex, aneurysm type,intraoperative rupture rates, operative time,anatomical obstacles,outcome and postoperative complications.

RESULTS

The 2 groups were comparable with respect to baseline characteristics. The mean operation time was also signifcantly shorter in frontolateral group than in the pterion group (204.3 min vs. 264.1 min, p < 0.05). Furthermore, the mean craniotomy area was much smaller in the frontolateral group (1255.4 mm² vs. 2758.5 mm², p < 0.05). No patient experienced rebleeding in either group. In the frontolateral group, the exploration allows enough room for intracranial manipulation with maximal protection of the brain and other intracranial structures.

CONCLUSION

The frontolateral approach is a simple, reliable, and efficient procedure. The frontolateral approach could be a good alternative to the classic pterional approach for the treatment of paraclinoid aneurysms.

[On the classification of large and giant paraclinoid internal carotid artery aneurysms]

Large and giant intradural ICA aneurysms or the so-called paraclinoid aneurysms are a surgical challenge requiring high qualification of the neurosurgeon. Despite numerous publications on this topic, there is still no generally accepted classification of paraclinoid aneurysms. In this paper, we analyzed the definitions and classifications of paraclinoid aneurysms, which were available in the medical literature. The paper presents our own surgical classification of paraclinoid ICA aneurysms, which has been developed by Prof. Sh.Sh. Eliava and co-authors at the Burdenko Neurosurgical Institute. The classification is based on the aneurysm neck position relative to the ICA wall, aneurysm dome direction, and type of aneurysm clipping.

Microsurgical treatment of carotid-ophthalmic aneurysm associated with multiple anterior and posterior circulation aneurysms: A case report

BACKGROUND

The clipping of multiple intracranial aneurysms in 1 stage is uncommon. In this case, we report clipping of an ophthalmic aneurysm associated with multiple anterior and posterior circulation aneurysms via the Dolenc approach.

METHODS

The main symptoms of the patient are headache, along with nausea and vomiting. The patient's arteriogram revealed a wide-necked aneurysm of the right ophthalmic artery, an irregular aneurysm of the anterior communicating artery, and a basilar artery aneurysm. The surgical intervention for these aneurysms is a challenge because of the complex anatomical relationship with the surrounding structures. The 3 aneurysms, which were not amenable to a single intervention, were successfully clipped in 1 incision.

RESULTS

After surgery, the patient reported feeling well. One year after surgery, the patient had no SAH recurrence.

CONCLUSIONS

Occasionally, surgical treatment was used even for aneurysms of the carotid-ophthalmic artery with aneurysms of anterior communicating artery and basilar artery, which are contraindicated for interventional therapy.

[The modern role of microsurgery in treatment of large and giant aneurysms of the internal carotid artery]

INTRODUCTION

Large (1.5-2.5 cm) and giant (>2.5 cm in diameter) aneurysms of the internal carotid artery (ICA) remain one of the complex neurosurgical pathologies in terms of microsurgery. In recent years, endovascular techniques for treatment of paraclinoid aneurysms, in particular ICA reconstruction using flow-diverting stents, have become a priority. However, surgery of flow stents has a number of limitations, therefore the choice of treatment in each case is individual.

PURPOSE

To analyze the results of direct surgery in patients with large and giant aneurysms of the ICA and to determine the role and place of modern microsurgical techniques in the treatment of this vascular disease.

MATERIAL AND METHODS

The study included 260 patients with large and giant ICA aneurysms who were operated on at the Institute using microsurgical techniques in the period between 2001 and 2015. The mean age of patients was 45.1 years. The male/female ratio was 1:2.5. One hundred sixty four (63.1%) patients were operated on after hemorrhages, of whom 15 (5.7%) patients were operated on in the acute period; 69 (26.5%) patients had a pseudotumoral course of the disease; 9 (3.5%) patients had a mixed course of the disease; aneurysms were incidentally found in 18 (6.9%) patients. The aneurysm localization was as follows: paraclinoid aneurisms in 158 (60.7%) patients, supraclinoid aneurisms in 77 (29.6%) patients, and ICA bifurcation aneurisms in 25 (9.6%) patients. Microsurgical clipping was performed in 228 (87.7%) patients, including 158 (60.7%) patients in whom an intravascular blood aspiration technique was used. Aneurysm trapping using a flowmetry probe was performed in 16 patients, with creating vascular anastomoses in 4 (1.5%) cases. In 16 (6.2%) patients, interventions were completed by gauze strengthening. We performed a comparative analysis of the results of endovascular treatment of paraclinoid aneurysms reported in recent publications and obtained in the present series.

RESULTS

Treatment outcomes (Glasgow Outcome Scale) were favorable (Grade 4-5) in 224 (86.2%) patients and satisfactory in 29 (11.1%) patients. Two patients (0.7%) developed diencephalic (electrolyte) disturbances that were successfully corrected using replacement therapy. The mortality was 2.7% (7 patients); the treatment completeness was 94.3%. Comparison with the literature data demonstrated comparable results for both treatment techniques.

CONCLUSION

Microsurgical techniques in treatment of large and giant ICA aneurysms are the methods of choice in complex non-standard cases where endovascular treatment is ineffective or contraindicated. Planning of microsurgical treatment should include the possibility of revascularization surgery. Treatment of these patients should be carried out at large dedicated centers having appropriate expertise and facilities.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Endoscopic Endonasal Clipping of Intracranial Aneurysms: Surgical Technique and Results

OBJECTIVE

Microsurgical clipping of intracranial aneurysms requires meticulous technique and is usually performed through open approaches. Endoscopic endonasal clipping of intracranial aneurysms may use the same techniques through an alternative corridor. The aim of this article is to report a series of patients who underwent an endoscopic endonasal approach (EEA) for microsurgical clipping of intracranial aneurysms.

METHODS

We conducted a retrospective chart review. Surgical outcome and complications were noted. The conceptual application and the technical nuances of these procedures are discussed.

RESULTS

Ten patients underwent EEA for clipping of 11 intracranial aneurysms arising from the paraclinoidal internal carotid artery (n = 9) and vertebrobasilar system (n = 2). The internal carotid artery aneurysms projected medially, whereas the vertebrobasilar artery aneurysms were directly ventral to the brainstem with low-lying basilar apices. One patient required craniotomy for distal control given the size and thrombosed nature of the aneurysm. Proximal and distal vascular control with direct visualization of the aneurysm was obtained in all patients. In all cases, aneurysms were completely occluded. Among complications, 3 patients had postoperative cerebrospinal fluid leakage and 2 other patients had meningitis. Two patients suffered lacunar strokes. One recovered completely and the other remains with mild disabling symptoms.

CONCLUSIONS

EEAs can provide direct access for microsurgical clipping of rare and carefully selected intracranial aneurysms. The basic principles of cerebrovascular surgery have to be followed throughout the procedure. These surgeries require a skull base team with a neurosurgeon well versed in both endoscopic endonasal and cerebrovascular surgery, working in concert with an otolaryngologist experienced in skull base endoscopy and reconstruction.

A trapping-evacuation technique for giant carotid-ophthalmic segment aneurysm clipping in a hybrid operating theater

It is essential to collapse giant carotid-ophthalmic (OA) segment aneurysms for successful microsurgical clipping. We present a trapping-evacuation technique utilising hybrid operating theater capabilities to soften OA aneurysms. The patients were prepared for both microsurgical and endovascular procedures. After the majority of the aneurysm was exposed, a balloon was placed at the orifice of the aneurysm to fully block the blood flow. When the balloon was inflated, blood was evacuated from the aneurysm sac to eliminate the space occupying effect. Subsequently, the aneurysm neck was clearly exposed which greatly facilitated clip placement. A control angiogram was obtained prior to closing the wound to ensure complete aneurysm obliteration. After the establishment of a hybrid operating theater in our hospital, two aneurysms were successfully clipped using this technique. Although postoperative complications occurred in both patients, none of the events were related to the endovascular procedure or the trapping-evacuation technique. As a well-organized procedure designed for use in a hybrid operating theater, the current trapping-evacuation technique is an option for the surgical clipping of giant OA aneurysms.

Role of superior hypophyseal artery in visual function impairment after paraclinoid carotid artery aneurysm surgery

OBJECT

Although a number of studies have assessed the surgical treatment of paraclinoid-segment carotid artery aneurysms and resulting visual complications, less attention has been given to the results with respect to the superior hypophyseal artery (SHA). The authors evaluated the relationship between the aneurysm, the SHA itself, and postoperative visual function in patients with ruptured and unruptured SHA aneurysms.

METHODS

From January 1991 through December 2013, 181 patients with 190 paraclinoid carotid artery aneurysms received treatment at Shinshu University Hospital and its affiliated hospitals. The authors retrospectively analyzed charts, operative records, operative videos, and neuroimaging findings for these patients with or without postoperative visual complications.

RESULTS

The authors identified 72 SHA aneurysms in 70 patients (mean age 58 years). Of 69 patients (1 patient died) evaluated, postoperative visual complications occurred in 9 (13.0%). Although the aneurysm size and SHA sacrifice did not lead to postoperative visual impairment, simultaneous treatment of bilateral aneurysms was a risk factor for postoperative visual complications.

CONCLUSIONS

Unilateral SHA impairment may be safe (i.e., it may not induce ischemia of the optic pathway) for many, but not all, patients with SHA aneurysm.

Visual outcomes of endovascular and microsurgical treatment for large or giant paraclinoid aneurysms

BACKGROUND

The optimal treatment for large or giant paraclinoid aneurysms is still controversial. The present study evaluated the results of endovascular coiling and microsurgical clipping with special reference to visual outcomes.

METHODS

The clinical data and treatment outcomes of 39 cases of large (>15 mm) paraclinoid aneurysms were retrospectively reviewed. Presenting symptoms were subarachnoid hemorrhage in 16 aneurysms and visual impairment in 18. Twenty-one aneurysms were treated by endovascular therapy and 18 were treated by direct surgery.

RESULTS

Maximal aneurysm diameter ≥25 mm and preoperative visual acuity <20/100 were significantly related to poor visual outcome in univariate analysis. However, preoperative visual acuity was the only significant prognostic factor in multivariate analysis (odds ratio [OR] 0.12, 95 % confidence interval [CI] 0.01-0.95, p = 0.04). Although patients treated with endovascular coiling tended to have more favorable outcome than those with surgical clipping, adjustment for other confounding factors reduced the OR of favorable outcome following each treatment modality to nearly one (OR 1.14, 95 % CI 0.17-7.46, p = 0.89). Deteriorations in the visual field showed different patterns: upper visual field deficit after endovascular coiling, and inferior nasal quadrantanopia after microsurgical clipping.

CONCLUSIONS

Preoperative visual acuity was the only independent predictor of visual outcome in patients with large paraclinoid aneurysms. Although adjusted visual outcomes with microsurgical clipping and endovascular coiling were almost the same, selection of the optimal treatment for each aneurysm is essential with recognition of the potential risks and mechanisms of visual impairment.

Management strategy of surgical and endovascular treatment of unruptured paraclinoid aneurysms based on the location of aneurysms

OBJECTIVE

Advances in endovascular treatment (EVT) have greatly improved the treatment outcomes of paraclinoid aneurysms. However, EVT had the shortcoming of durability and thromboembolic complications. As well, surgical treatment of paraclinoid aneurysms is still challenging due to the complexity of adjacent structures. The objective of this study is to report our experience with a combined surgical and endovascular treatment of unruptured paraclinoid aneurysms based on the location of aneurysms.

METHODS

A retrospective review was conducted of 185 cases of unruptured paraclinoid aneurysms that underwent surgical or endovascular treatment between September 2008 and August 2012. Thirty-one aneurysms (16.8%) were treated by microsurgery and 154 (83.2%) were treated by EVT. Fifty aneurysms (27.0%) were classified to the dorsal group and 135 (73%) were classified to the non-dorsal group.

RESULTS

Twenty of 50 dorsal group aneurysms (40%) were treated by microsurgery while 124 of 135 non-dorsal group aneurysms (91.9%) underwent an EVT. The rate of complete occlusion was 96.8% in surgical series and 60.4% in EVT (P < 0.001). Recanalization occurred in 9 aneurysms (5.8%) of EVT and 1 aneurysm (3.2%) of surgical series (P = 0.360). In non-dorsal group, transient complications (10 aneurysms (5.4%), P = 0.018) and morbidity at last visiting (6 aneurysms (3.2%), P = 0.021) were more present in surgically treated cases rather than in EVT cases. Diplopia and visual field defect occurred in the non-dorsal group only; in 2 of 11 surgical cases (18.2%) and in 1 of 124 EVT series (0.8%) (P = 0.017). The overall rate of excellent or good clinical outcomes (Glasgow outcome scale 5 or 4) was 98.9%.

CONCLUSION

EVT is a safe and effective treatment for the non-dorsal group. Based on angiographic and clinical aspects, microsurgical clipping has prior efficacy with better outcomes in the dorsal group under proper individualized selection.

Clinical outcome of paraclinoid internal carotid artery aneurysms after microsurgical neck clipping in comparison with endovascular embolization

OBJECTIVE

Because of the complex anatomical association among vascular, dural, and bony structures, paraclinoid internal carotid artery (ICA) aneurysms remain a major challenge for vascular neurosurgeons. We studied the clinical outcomes of 61 paraclinoid ICA aneurysms after microsurgical clipping in comparison with endovascular coiling.

MATERIALS AND METHODS

Between January 2008 and December 2012, we treated 61 paraclinoid ICA aneurysms created by surgical clipping or endovascular coiling. Preoperative neurologic status and postoperative outcome were evaluated using the Glasgow coma scale (GCS) and the modified Rankin scale (mRS). Postoperative hydrocephalus and vasospasm were reviewed using the patients' medical charts.

RESULTS

Most patients were in good clinical condition before the operations and had good treatment outcomes. Clinical vasospasm was observed after the operation in five patients, and hydrocephalus occurred in six patients. No statistically significant difference regarding aneurysm size, sex, GCS score, H-H grade, and mRS was observed between the surgical clipping group and the endovascular coiling group. In addition, the treatment results and complications did not show statistically significant difference in either group.

CONCLUSION

Surgical occlusion of paraclinoid ICA aneurysms is difficult; however, no significant differences were observed in the treatment results or complications when compared with coil embolization. In particular, use of an adequate surgical technique may lead to better outcomes than those for coil embolization in the treatment of large and/or wide-neck paraclinoid ICA aneurysms.

A retrospective analysis on the natural history of incidental small paraclinoid unruptured aneurysm

OBJECTIVE

The optimal consensus concerning treatment of incidental small paraclinoid unruptured intracranial aneurysms (UIAs) remains controversial. The aim of this retrospective study was to reveal the natural history of small paraclinoid UIAs with the goal of informing the treatment plan.

METHODS

524 patients harbouring 568 paraclinoid UIAs (≤5 mm) were retrospectively evaluated during the mean follow-up of 35.4 months. The aneurysms were divided into two groups with respect to arterial branch: related (ophthalmic and superior hypophyseal artery), and non-related. Medical records were reviewed concerning multiple variables, such as sex, age, hypertension (HTN), diabetes mellitus, smoking and aneurysmal factors (size, arterial relationship, multiplicity and the occurrence of rupture and growth). The cumulative risk and the risk factors of aneurysmal rupture and growth were analysed.

RESULTS

Two aneurysmal (0.35%) ruptures and 17 growths (3.0%) were observed during the follow-up of 1675.5 aneurysm-years with an annual rupture of 0.12% and an annual growth of 1.01%. The cumulative survival without aneurysmal growth reached a significant difference in aneurysms ≥4 mm (p=0.001), HTN (p=0.002), and arterial branch-related location (p=0.001). Multivariate analysis disclosed that aneurysm ≥4 mm (HR, 4.41; p=0.003), HTN (HR, 5.74; p=0.003), arterial branch-related location (HR, 6.04; p=0.002), and multiplicity (HR, 0.27; p=0.042) were significant predictive factors for aneurysm growth.

CONCLUSIONS

Although incidental small paraclinoid UIAs have a relatively lower rupture and growth risk, patients with high-risk factors, including aneurysm ≥4 mm, HTN, arterial branch-related aneurysms, and multiple aneurysms must be monitored closely. The limitation of the retrospective nature of this study should be taken into consideration.

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.

Safety of drilling for clinoidectomy and optic canal unroofing in anterior skull base surgery

BACKGROUND

Skull base drilling is a necessary and important element of skull base surgery; however, drilling around vulnerable neurovascular structures has certain risks. We aimed to assess the frequency of complications related to drilling the anterior skull base in the area of the optic nerve (ON) and internal carotid artery (ICA), in a large series of patients.

METHODS

We included anterior skull base surgeries performed from 2000 to 2012 that demanded unroofing of the optic canal, with extra- or intradural clinoidectomy and/or drilling of the clinoidal process and lateral aspect of the tuberculum sella. Data was retrieved from a prospective database and supplementary retrospective file review. Our IRB waived the requirement for informed consent. The nature and location of pathology, clinical presentation, surgical techniques, surgical morbidity and mortality, pre- and postoperative vision, and neurological outcomes were reviewed.

RESULTS

There were 205 surgeries, including 22 procedures with bilateral optic canal unroofing (227 optic canals unroofed). There was no mortality, drilling-related vascular damage, or brain trauma. Complications possibly related to drilling included CSF leak (6 patients, 2.9 %), new ipsilateral blindness (3 patients, 1.5 %), visual deterioration (3 patients, 1.5 %), and transient oculomotor palsy (5 patients, 2.4 %). In all patients with new neuropathies, the optic and oculomotor nerves were manipulated during tumor removal; thus, new deficits could have resulted from drilling, or tumor dissection, or both.

CONCLUSION

Drilling of the clinoid process and tuberculum sella, and optic canal unroofing are important surgical techniques, which may be performed relatively safely by a skilled neurosurgeon.

Visual outcomes for surgical treatment of large and giant carotid ophthalmic segment aneurysms: a case series utilizing retrograde suction decompression (the “Dallas technique”)

Object

The authors report their results in a series of large or giant carotid ophthalmic segment aneurysms clipped using retrograde suction decompression.

Methods

A retrospective review of clinical data and treatment summaries was performed for 18 patients with large or giant carotid artery ophthalmic segment aneurysms managed operatively via retrograde suction decompression. Visual outcomes, Glasgow Outcome Scale (GOS) scores, and operative complications were determined. Postoperative angiography was assessed.

Results

During a 17-year period, 18 patients underwent surgery performed using retrograde suction decompression. The mean aneurysm size was 26 mm. Three patients presented with subarachnoid hemorrhage. Fourteen of 18 patients presented with visual symptoms. Eleven (79%) of these 14 patients experienced visual improvement and the remaining 3 (21%) experienced worsened vision after surgery. Of 3 patients without visual symptoms and a complete visual examination before and after surgery, 1 had visual worsening postoperatively. One aneurysm required trapping and bypass, and all others could be clipped. Postoperative angiography demonstrated complete occlusion in 9 of 17 clipped aneurysms and neck remnants in the other 8 clipped aneurysms. One (5.5%) of 18 patients experienced a stroke. Eighteen patients had a GOS score of 5 (good outcome), and 1 patient had a GOS score of 4 (moderately disabled). There were no deaths. There was no morbidity related to the second incision or decompression procedure. Prolonged improvement did occur, and even in some cases of visual worsening in 1 eye, the overall vision did improve enough to allow driving.

Conclusions

Retrograde suction decompression greatly facilitates surgical clipping for large and giant aneurysms of the ophthalmic segment. Visual preservation and improvement occur in the majority of these cases and is an important outcome measure. Developing endovascular technology must show equivalence or superiority to surgery for this specific outcome.

Visual sequelae after consensus-based treatment of ophthalmic artery segment aneurysms: the Johns Hopkins experience

BACKGROUND

To determine the anatomic and visual outcomes of patients with ophthalmic artery segment aneurysms treated at The Johns Hopkins Hospital using a consensus-based treatment algorithm.

METHODS

Retrospective record review of a prospectively accrued case series of 88 patients (101 aneurysms) treated between January 2004 and July 2009. Presenting symptoms and aneurysm parameters were recorded for all subjects. Treatment strategy for all patients was determined by consensus among neurosurgeons, neurointerventionalists, neurologists, and neuroophthalmologists meeting to review the clinical cases on a weekly basis. Final clinical outcomes (aneurysm control, functional status, and vision) were ascertained from in-house examinations, medical records, telephone interviews, or a combination of these methods. Risk factors for visual or other complications were evaluated.

RESULTS

An optic neuropathy was present in at least 30 (34%) of 88 patients after treatment. Presumed new visual loss occurred in 24 (27%) of these patients. The remaining 6 patients had preexisting optic neuropathy-related visual loss that worsened after treatment. No patient with a preexisting optic neuropathy improved following treatment.

CONCLUSION

Ophthalmic artery segment aneurysms present a treatment challenge because of their anatomic complexity and relationship to critical neural structures, particularly the visual sensory pathway. We have adopted a consensus-based treatment approach in an effort to optimize patient outcomes and aneurysm control. Although our approach resulted in durable treatment of the aneurysm, a sizable proportion of patients experienced new vision loss after treatment, and no patient with preexisting visual loss related to their aneurysm experienced visual improvement after treatment. We recommend that all patients with ophthalmic artery aneurysms receive careful and thorough preprocedural counseling to ensure they are aware of the risks and benefits of treatment regardless of the method used.

Superior hypophyseal artery aneurysms have the lowest recurrence rate with endovascular therapy

BACKGROUND AND PURPOSE

Given the challenges posed by surgical clipping, endovascular techniques have been increasingly used to treat SHA aneurysms. The purpose of this study was to assess the safety and efficacy of endovascular techniques in the treatment of SHA aneurysms.

MATERIALS AND METHODS

Medical charts and initial and follow-up angiograms were reviewed retrospectively for all patients treated with endovascular procedures at our institution between January 2006 and February 2011.

RESULTS

We identified 87 patients with SHA aneurysms who were treated with endovascular techniques. Of these patients, 79 were women and only 8 were men (90.8% female predominance). Thirty-five patients were treated with coil embolization; 45, with stent-assisted coiling; 4, with balloon-assisted coil embolization; and 3, with a flow-diversion technique. Minor complications occurred in 2 patients (2.2%). None of the patients had a major complication. The mortality and permanent morbidity rates related to the procedure were 0%. Imaging follow-up was available for 89.4% of patients (DSA in 65, MRA in 11 patients) at a mean time point of 10.4 months (range, 6-60 months). Of the 76 patients with available follow-up, 3 patients had a recurrence (3.9%) and only 1 required further intervention (1.3%). Stent-assisted coiling was associated with lower recurrence rates than simple coil embolization.

CONCLUSIONS

SHA aneurysms have the lowest recurrence rate with endovascular treatment compared with aneurysms in other locations by using historical data. Because of its safety and efficacy, endovascular therapy should be considered the procedure of choice for the treatment of SHA aneurysms.

Long-term visual outcome and aneurysm obliteration rate for very large and giant ophthalmic segment aneurysms: assessment of surgical treatment

BACKGROUND

Standard endovascular therapy has shown little success in treatment of very large and giant ophthalmic segment aneurysms. We hypothesize that surgical treatment of these aneurysms yields better results in terms of visual function and aneurysm obliteration.

METHODS

The Toronto Brain Vascular Malformation Study Group database was analyzed to retrieve patients treated surgically for very large (>15 mm) and giant aneurysms of the ophthalmic segment of the carotid artery. Preoperative data and postoperative long-term outcomes with specific consideration for visual function and aneurysm obliteration were evaluated.

RESULTS

Of the 257 patients with ophthalmic and paraophthalmic aneurysms, 38 patients had very large or giant aneurysms. Twenty-one underwent surgical treatment; 19 had direct clipping; 1 had trapping, and 1 underwent trapping and bypass. Fifteen patients had unruptured and six had ruptured aneurysms. The mean follow-up period was 88 months. Six (28%) aneurysms had a small residual neck remnant. Of the 12 patients with documented preoperative visual deficit, 9 (75%) improved, 2 (16%) remained stable, and 1 (8%) worsened. Two patients had mild to moderate new visual deficit. Thus, the surgery-related visual complications were 14%. Eighteen patients (86%) had a good or excellent outcome (GOS IV and V). Presentation with prior visual deficit and poor neurological function were predictors of worse visual and clinical outcome, respectively (P = 0.02 and 0.01).

CONCLUSIONS

There is considerable surgery-related risk for optic pathways during treatment of very large and giant ophthalmic segment aneurysms. Surgery, however, seems to be the treatment of choice in terms of overall visual outcome and aneurysm obliteration as compared to the current endovascular results in this subset of patients.

Association of Intracranial Aneurysm and Loeys-Dietz Syndrome: Case Illustration, Management, and Literature Review

BACKGROUND AND IMPORTANCE:

Loeys-Dietz syndrome (LDS) is a newly described connective tissue disease associated with aortic aneurysms. A strong association between LDS and intracranial aneurysms has not yet been documented in the literature. We present the first detailed report of an intracranial aneurysm finding in an LDS patient.

CLINICAL PRESENTATION:

The patient is a 20-year-old female recently diagnosed with LDS and found to harbor 2 incidental intracranial aneurysms on a screening magnetic resonance angiography: a 3-mm right carotid ophthalmic aneurysm and an 8-mm partially fusiform paraclinoid carotid artery aneurysm. A standard left pterional craniotomy was performed. Intraoperative adenosine was used instead of temporary clipping because her vessels were extremely friable. After reconstruction, an intraoperative indocyanine green angiogram was obtained, confirming complete aneurysmal obliteration and internal carotid artery patency.

CONCLUSION:

This is the first detailed report of a clear association between intracranial aneurysms and LDS. An association between LDS and intracranial aneurysms, if substantiated in a larger study, has implications for aneurysm screening in this population. Such an association may shed light on mechanisms of aneurysm formation, growth, and rupture.

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.