Anatomical and technical aspects of the contralateral approach for multiple aneurysms

Clinical Characteristics and Outcome of Patients with Multiple Intracranial Aneurysms from a University Hospital in Nepal

Objective  The risk factors, management strategies, and outcomes of patients with multiple intracranial aneurysms (MIAs) are different compared with that of patients with a single aneurysm. Data are scarce regarding patients with MIAs from developing countries. The objective of this study was to describe the clinical characteristics, management strategies, and outcomes of patients treated microsurgically from Nepal.

Methods  The clinical records of patients confirmed to have MIAs and microsurgically clipped between July 2014 and December 2019 were retrospectively reviewed. Data on demographic and clinical characteristics, computed tomography findings, multiplicity and location of aneurysms, management strategies, and the 1-year outcome were abstracted and analyzed.

Results  Two hundred cerebral aneurysms were microsurgically clipped in 170 consecutive patients during the study period. Twenty-six (13.0%) patients harbored 60 aneurysms. The mean age of the patients was 58.5 (43–73) years. Smoking and hypertension were found in 20 (76.9%) and 16 (61.5%) patients, respectively. The majority of patients [17 (65.4%)] were in good grades at presentation. Twenty-one patients had two aneurysms, four had three aneurysms, and one patient had five aneurysms. The middle cerebral artery was the commonest (20) followed by distal anterior cerebral artery (14) and anterior communicating artery (13) involved in multiplicity. A single-stage surgery was performed on 17 patients. Serial clipping was performed in six patients. In three patients, a single aneurysm on the contralateral side was left untreated for various reasons. The favorable outcome was achieved in 23 (88.5%) patients whereas three (11.5%) patients had an unfavorable outcome. One patient died.

Conclusion  The demographic and clinical characteristics of patients in our series are comparable with those described in the published literature from other countries. With an individualized treatment strategy, an acceptable outcome can be achieved in the majority of the patients.

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.

Treatment outcomes of 1-stage clipping of multiple unruptured intracranial aneurysms via keyhole approaches

OBJECTIVE

Complete exclusion of multiple unruptured intracranial aneurysms (UIAs) in one session of intervention may be ideal. However, such situations are not always feasible in terms of treatment modalities and outcomes. The authors aimed to analyze their experience with 1-stage clipping of multiple UIAs.

METHODS

Medical records between March 2013 and December 2018 were retrospectively reviewed, and 111 1-stage keyhole approaches in 110 patients with 261 multiple UIAs were ultimately included in this study. Clinical and radiological outcomes were analyzed, as well as postoperative complications up to 1 month after the surgery and their risk factors.

RESULTS

Keyhole approaches included unilateral supraorbital in 87 operations (78.4%), bilateral supraorbital in 12 (10.8%), and others in 12. The mean operative duration was 169.6 minutes (range 80-490 minutes). The highest numbers of aneurysms clipped at once were 2 (73.9%) and 3 (18.9%). Complete exclusion and residual neck of the clipped aneurysms were achieved in 89.3% and 7.3%, respectively. There was no significant difference between pre- and postoperative 1-month neurological states (p = 0.14). The permanent morbidity rate was 1.8% (n = 2), and there were no deaths. Postoperative transient neurological deterioration (TND) with no radiological and electrophysiological abnormalities occurred in 8 operations (7.2%). Hypertension was the only significant risk factor for postoperative TND (adjusted odds ratio 17.03, 95% confidence interval 1.99-2232.24, p = 0.01).

CONCLUSIONS

One-stage clipping of multiple UIAs via keyhole approaches showed satisfactory treatment outcomes with a low permanent morbidity. Patients with chronic hypertension had a high risk of postoperative TND.

Microsurgical clipping of multiple cerebral aneurysms in the acute phase of aneurysmal subarachnoid hemorrhage through a minipterional approach: The Chilean experience

OBJECTIVE

The minipterional craniotomy (MPTc) has been widely accepted as a minimally invasive alternative to the pterional approach for the treatment of certain small non-ruptured anterior circulation aneurysms. The aim of this study was to determine the effectiveness and safety of the MPTc in the context of a complex and potentially harmful scenario: acute onset of subarachnoid hemorrhage (SAH) in patients harboring multiple intracranial aneurysms (MIA).

METHODS

Patients harboring MIA clipped through a unilateral MPTc were selected from four retrospective databases of four high-volume neurosurgical centers. Patients with a Hunt & Hess score 4 or 5 were not considered candidates for clipping through a MPTc. Medical records and radiological images were retrospectively reviewed. Epidemiological, clinical and radiological data, as well as short-term outcome (modified Rankin scale at 6 month-follow-up) were analyzed.

RESULTS

16 patients harboring 33 aneurysms (16 ruptured, 17 non ruptured) met the inclusion criteria. Each aneurysm size was 5.7 ± 2.1 mm (range 3-11). 12 out of 33 aneurysms were located in the middle cerebral artery (MCA). Anterior communicating (ACom) and MCA aneurysms were the aneurysm locations most commonly ruptured (5 each, 62 %). Complete occlusion was achieved in 32 aneurysms (97 %) and near-complete occlusion in 1 (3%). 13 patients (93 %) were independent at 6 month-follow-up. Mortality rate was 0%. Complications included 1 cerebrospinal-fluid leakage.

CONCLUSION

When indicated (Hunt Hess < 4), performing a MPTc is safe and effective in aSAH cases with multiple aneurysms.

One-stage Operation with Ipsilateral Two-Piece Craniotomies for a Case of Subarachnoid Hemorrhage with Multiple Intracranial Aneurysms

Subarachnoid hemorrhage (SAH) with multiple intracranial aneurysms is common, but the difficulties often arise in determining treatment strategy in the acute phase. We experienced a case of SAH with distal anterior cerebral artery aneurysm coexisting with middle cerebral artery and anterior communicating artery aneurysms, in which it was difficult to identify the precise rupture site preoperatively, and both pterional approach and interhemispheric approach were required in the acute phase of SAH. However, we could treat whole aneurysms in one stage and obtained an excellent outcome using our surgical procedure with ipsilateral frontotemporal and frontal parasagittal craniotomies through a single skin incision.

[Bilateral supraorbital keyhole approach in surgery of multiple cerebral aneurysms: a case report and literature review]

The choice of an approach in surgery of bilateral multiple aneurysms is a complex and topical issue. According to the literature data, the occurrence rate of multiple aneurysms varies between 6.5 and 33%. Many authors have proposed various modern microsurgical approaches to reduce the risk of adverse surgical outcomes. The need for surgery in several vascular territories requires a detailed assessment of the topographo-anatomical relationships upon choosing a surgical approach. An important issue is preliminary planning and personalization of an approach for a particular patient.

MATERIAL AND METHODS

We report a case of clipping of mirror middle cerebral artery aneurysms using a minimally invasive bilateral approach.

RESULTS

The presented case demonstrates successful clipping of middle cerebral artery aneurysms in different vascular territories using the bilateral supraorbital approach: a skin incision along the eyebrow followed by supraorbital keyhole craniotomy. Follow-up CT angiography in the postoperative period demonstrated elimination of aneurysms from the bloodstream. The cosmetic effect after the intervention was evaluated as excellent.

CONCLUSION

The bilateral supraorbital approach in surgery of multiple mirror aneurysms may be recommended as an alternative to the contralateral or bilateral pterional approach. The bilateral supraorbital approach avoids additional traction of the frontal lobes, provides a focused personalized approach, and is a safe and effective approach with excellent cosmetic results.

The approach angle to the interoptic triangle limits surgical workspace when targeting the contralateral internal carotid artery

BACKGROUND

The interoptic triangle (IOT) offers a key access to the contralateral carotid artery's ophthalmic segment (oICA) and its perforating branches (PB), the ophthalmic artery (OA), and the superior hypophyseal artery (SHA). It has been previously reported that the assessment of IOT's size is relevant when attempting approaches to the contralateral oICA. However, previous studies have overseen that, since the oICA is a paramedian structure and a lateralized contralateral approach trajectory is then required, the real access to the oICA is further limited by the approach angle adopted by the surgeon with respect to the IOT's plane. For this reason, we determined the surgical accessibility to the contralateral oICA and its branches though the IOT by characterizing the morphometry of this triangle relative to the optimal contralateral approach angle.

METHODS

We defined the "relative interoptic triangle" (rIOT) as the two-dimensional projection of the IOT to the surgeon's view, when the microscope has been positioned with a certain angle with respect to the midline to allow the maximal contralateral oICA visualization. We correlated the surface of the rIOT to the visualization of oICA, OA, SHA, and PBs on 8 cadavers and 10 clinical datasets, using for the last a 3D-virtual reality system.

RESULTS

A larger rIOT correlated positively with the exposure of the contralateral oICA (R = 0.967, p < 0.001), OA (R = 0.92, p < 0.001), SHA (R = 0.917, p < 0.001), and the number of perforant vessels of the oICA visible (R = 0.862, p < 0.001). The exposed length of oICA, OA, SHA, and number PB observed increased as rIOT's surface enlarged. The correlation patterns observed by virtual 3D-planning matched the anatomical findings closely.

CONCLUSIONS

The exposure of contralateral oICA, OA, SHA, and PB directly correlates to rIOT's surface. Therefore, preoperative assessment of rIOT's surface is helpful when considering contralateral approaches to the oICA. A virtual 3D planning tool greatly facilitates this assessment.

Contralateral approach for the treatment of a distal supraclinoid aneurysm: a technical case report

Background: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm. Case Description: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications. Conclusions: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Comprehensive Anatomic Assessment of Ipsilateral Pterional Versus Contralateral Subfrontal Approaches to the Internal Carotid Ophthalmic Segment: A Cadaveric Study and Three-Dimensional Simulation

OBJECTIVE

Medially pointing aneurysms of the ophthalmic segment of the internal carotid artery (oICA) represent a neurosurgical challenge. Conventional ipsilateral approaches require internal carotid artery and optic nerve (ON) mobilization as well as anterior clinoidectomy (AC), all associated with increased surgical risk. Contralateral approaches could provide a better exposure of the superomedial aspect of the oICA, ophthalmic artery, and superior hypophyseal artery, sparing AC and internal carotid artery or ON mobilization. However, the microsurgical anatomy of this approach has not been systematically studied. In the present work, we exhaustibly analyzed the anatomic and morphometric characteristics of contralateral approaches to the oICA and compared them with those from ipsilateral approaches.

METHODS

We assessed 36 ipsilateral and contralateral approaches to the oICAs in cadaveric specimens and live patients, using for the latter a three-dimensional virtual reality (VR) system.

RESULTS

Contralateral approaches spared sylvian fissure dissection and required only minimal frontal lobe retraction. The ipsilateral and contralateral oICA were found at a depth of 49.2 ± 1.8 mm (VR, 50.1 ± 2.92 mm) and 65.1 ± 1.5 mm (VR, 66.05 ± 3.364 mm) respectively. The exposure of the superomedial aspect of oICA was 7.25 ± 0.86 mm (VR: 6 ± 1 mm) contralaterally without ON mobilization and 2.44 ± 0.51 mm (VR, 2 ± 1 mm) ipsilaterally even after AC. Statistical analysis showed that, for nonprefixed chiasm, contralateral approaches achieved a significantly higher exposure of the ophthalmic artery, superior hypophyseal artery, and the superomedial aspect of the oICA with its perforating branches (all P < 0.01).

CONCLUSIONS

Contralateral approaches may enable successful exposure of the oICA and related vascular structures, reducing the need for AC or ON mobilization. Systematic clinical/surgical studies are needed to further determine the effectiveness and safety of the approach.

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.

Fully Endoscope-Controlled Clipping Bilateral Middle Cerebral Artery Aneurysm Via Unilateral Supraorbital Keyhole Approach

Clipping bilateral middle cerebral artery (bMCA) aneurysms via unilateral approach in a single-stage operation is considered as a challenge procedure. To our knowledge, there is no study in surgical management of patients with bMCA aneurysms by fully endoscope-controlled techniques. The author reported a patient with bMCA aneurysms who underwent aneurysms clipping via a unilateral supraorbital keyhole approach by endoscope-controlled microneurosurgery, and the patient had an uneventful postoperative course without neurologic impairment and complication. Furthermore, the author discussed the advantages and adaptation of endoscope-controlled clipping bMCA aneurysms via unilateral supraorbital keyhole approach.

Contralateral Approach to Middle Cerebral Artery Aneurysms: An Anatomical-Clinical Analysis to Improve Patient Selection

BACKGROUND

A contralateral approach to aneurysm clipping in cases of bilateral middle cerebral artery (MCA) aneurysms reduces surgical time and cost. However, there is a lack of evidence for objective patient selection. In this study, we assessed the change in surgical freedom along the contralateral MCA to provide objective evidence for patient selection.

METHODS

Sixteen cadaveric specimens were studied. Through a pterional approach, the surgical freedom was calculated moving distally along the contralateral MCA in 5-mm increments. In addition, in a series of 19 MCA aneurysms clipped contralaterally by the senior author, the average length of the MCA from its origin to the aneurysm neck was measured on angiography.

RESULTS

In these patients treated via a contralateral approach, the average length of the MCA segment from its origin to the aneurysm neck was 12.4 mm. Starting at the MCA origin, surgical freedom decreased significantly between all adjacent target points except at 5-10 mm from the MCA origin.

CONCLUSIONS

After the proximal 5 mm, there is no significant decrease in surgical maneuverability within the proximal 10 mm of MCA when approached contralaterally. When compared to the average length of the MCA from its origin to the aneurysm neck in the clinical series, it can be concluded that the first 10 mm (average, 12.4 mm) of the contralateral MCA may be considered a surgical comfort zone for a contralateral approach. This criterion may be useful for patient selection for a contralateral approach in cases of multiple bilateral intracranial aneurysms.

Transient Cardiac Arrest Induced by Adenosine: A Tool for Contralateral Clipping of Internal Carotid Artery-Ophthalmic Segment Aneurysms

BACKGROUND

The disadvantages of a contralateral approach (CA) include deep and narrow surgical corridors and inconsistent ability to achieve proximal control of the supraclinoid internal carotid artery (ICA). However, a CA remains as a microsurgical option for selected ICA-ophthalmic (opht) segment aneurysms.

OBJECTIVE

To describe transient cardiac arrest induced by adenosine as an alternative tool to obtain proximal vascular control and soften the aneurysm sac in selected patients while performing a CA.

METHODS

From January 1998 to December 2013, we retrospectively identified 30 patients with ICA-opht segment aneurysms treated through a CA. Of those, 8 patients received an intravenous bolus of adenosine to induce transient cardiac arrest for softening of the aneurysm sac. We reviewed preoperative clinical status, characteristics of the contralateral aneurysm, adenosine doses, asystole time, recovery of normal circulation, outcome, and complications.

RESULTS

No preoperative cardiac or pulmonary pathologies were found in the study population. All contralateral ICA-opht segment aneurysms were unruptured, small, and saccular in shape. Transient cardiac arrest was induced because it was impossible to apply a temporary clip on the parent contralateral supraclinoid ICA. The median dose of adenosine was 22.5 mg (range, 5-50 mg) and the asystole time ranged from 20 to 40 seconds. All patients (n = 8) had good postoperative outcomes. No brain infarction or cardiac complications appeared postoperatively.

CONCLUSIONS

In selected patients, transient cardiac arrest induced by adenosine during a contralateral approach allows a brief flow arrest and softening of the aneurysm for safer exposure and clipping.

Contralateral Approach to Bilateral Middle Cerebral Artery Aneurysms: Comparative Study, Angiographic Analysis, and Surgical Results

BACKGROUND

Bilateral aneurysms located between the 2 middle cerebral artery (MCA) bifurcations may be approachable through a single unilateral approach.

OBJECTIVE

To identify anatomic parameters based on imaging that would favor a contralateral approach.

METHODS

From January 1998 to December 2013, we retrospectively identified 173 patients with bilateral intracranial aneurysms. Fifty-one patients had bilateral MCA aneurysms. A total of 38 patients underwent a single craniotomy with a contralateral microsurgical approach (group 1 or contralateral group) and 13 patients underwent bilateral craniotomies (group 2 or bilateral group). For both groups, we analyzed aneurysm characteristics, morphology, size, projections, and distance to the contralateral corridor, as well as surgical time, outcome, and postoperative complications.

RESULTS

All aneurysms approached contralaterally were unruptured and without wall calcifications. Of the contralaterally approached aneurysms, 97% were smaller than 14 mm. The median length of the contralateral A1 was 13.2 mm (range: 6-19.8 mm) and the median length of the contralateral M1 was 14.2 mm (range: 4.6-21 mm). The contralateral group had a good postoperative outcome (modified Rankin Scale 0-3) in 80% of ruptured cases and 86% of unruptured cases. The median surgical time was 120 minutes (range: 75-255 minutes), 43% shorter than the bilateral group.

CONCLUSION

The contralateral approach for bilateral MCA aneurysms in selected patients is feasible in experienced hands, with acceptable morbidity and mortality. The contralateral approach requires a meticulous preoperative analysis of the characteristics of the aneurysms to be clipped and of the anatomic constraints of the microsurgical operative corridor.

ABBREVIATIONS

A1, anterior cerebral artery proximal segmentbMCA, bilateral middle cerebral arteryCTA, computed tomographic angiographyHH, Hunt-Hess scaleIA, intracranial aneurysmsICA, internal carotid arteryICAbif, internal carotid artery bifurcationMCA, middle cerebral arteryM1, middle cerebral artery proximal segmentmRS, modified Rankin ScaleSAH, subarachnoid hemorrhage.

Contralateral Approach to Internal Carotid Artery Ophthalmic Segment Aneurysms: Angiographic Analysis and Surgical Results for 30 Patients

BACKGROUND

Contralateral aneurysm clipping can be applied to bilateral intracranial aneurysms of the anterior circulation and to selected aneurysms on the medial wall of the internal carotid artery (ICA).

OBJECTIVE

To identify anatomic and radiological parameters that would favor a contralateral microsurgical approach to ICA-ophthalmic segment (ICA-opht) aneurysms.

METHODS

For the period January 1957 to December 2012, we retrospectively analyzed 268 patients with ICA-opht aneurysms treated in our institution. Of these patients, 30 underwent a contralateral approach; 15 patients (50%) had multiple intracranial aneurysms, and 15 patients had a single aneurysm on the contralateral side of the craniotomy.

RESULTS

Thirty saccular aneurysms located on the contralateral ICA were treated. Six aneurysms (20%) were present in patients with a subarachnoid hemorrhage due to associated aneurysms, whereas 24 aneurysms (80%) had no history of bleeding. Contralateral aneurysms were smaller than 14 mm and showed no wall irregularities, calcifications, or secondary pouches. Projections of the aneurysms were superomedial (n = 23, 77%), medial (n = 4, 13%), and superior (n = 3, 10%). The median prechiasmatic distance was 5.7 mm (range, 3.4-8.7 mm), the median interoptic distance was 10.5 mm (range, 7.6-15.9 mm), and the median distance between both ICAs was 14.7 mm (range, 10.4-21.4 mm).

CONCLUSION

The contralateral approach for ICA-opht aneurysms remains a treatment option for intracranial aneurysms. Its feasibility depends on specific anatomic parameters related to the aneurysm itself and to the prechiasmatic distance, interoptic distance, and relationship of the ICA with the anterior clinoid process.

Bilateral middle cerebral artery aneurysms: a comparative study of unilateral and bilateral approaches

The best surgical method for the treatment of patients with bilateral middle cerebral artery (bMCA) aneurysms has not been fully determined yet. The main purpose of this study is to compare the surgical results of unilateral and bilateral approaches to bMCA aneurysms including mean operation time, mean hospital stay, and mean cost, in the experience of the same neurosurgical team. Between January 2001 and June 2010, 22 patients with bMCA aneurysms were surgically treated in our institution. In 12 cases (54.5 %), ipsilateral and contralateral MCA aneurysms were successfully clipped via unilateral approach. In the remaining 10 cases, bilateral approach was necessary because of some technical difficulties. Although the surgical results were almost the same, mean operation time and mean hospital stay were, respectively, 46 and 37 % shorter and mean cost per person was 23 % lower for the patients in the unilateral group. In addition, the severity of brain edema, total length of the contralateral (A1+M1) segment, and the configuration of contralateral aneurysm were found to be the determinant parameters affecting the feasibility of the unilateral approach. To our knowledge, this is the first study in the literature that compares the clinical outcomes of unilateral and bilateral approaches to bMCA aneurysms. The results of surgery for both approaches are almost the same. However, the unilateral approach has certain advantages compared to the bilateral approach. Therefore, the unilateral approach may be a good alternative in surgical management of patients with bMCA aneurysms in selected cases and the abovementioned parameters can help the neurosurgeon in patient selection.

Contralateral clipping of middle cerebral artery aneurysms: rationale, indications, and surgical technique

BACKGROUND

Contralateral clipping of middle cerebral artery (MCA) aneurysms seems dangerous and ill advised but could become an important technique because of the prevalence of MCA aneurysms, the limitations of endovascular therapy, and increasing interest in less invasive techniques.

OBJECTIVE

To define patient selection, surgical technique, and results with contralateral MCA aneurysm clipping.

METHODS

Forty-two patients with bilateral MCA aneurysms were treated either in 1 stage with a single craniotomy and contralateral aneurysm clipping (group 1, 11 patients) or in 2 stages with bilateral craniotomy (group 2, 31 patients). Surgical technique consisted of ipsilateral sylvian fissure split, subfrontal dissection, contralateral sylvian fissure split, mobilization of medial orbital gyrus, and contralateral aneurysm clipping.

RESULTS

Group 1 patients were older than group 2 patients (60.3 vs 55.4 years, respectively). Clinical presentation with subarachnoid hemorrhage was less common in group 1. Nine group 1 patients (82%) had left-sided craniotomies, and the ipsilateral aneurysm was larger than the contralateral aneurysm. All aneurysms were clipped without intraoperative complications (136 aneurysms). Mean neurosurgical charges were decreased by contralateral MCA aneurysm clipping: $39 297 in group 1 vs $57 977 in group 2.

CONCLUSION

Contralateral MCA aneurysm clipping can be viewed as an extreme microsurgical technique or as a less invasive technique that spares patients a second craniotomy in the management of bilateral aneurysms. This technique is acceptable in selected patients with contralateral aneurysms that are unruptured, have simple necks, project inferiorly or anteriorly, are associated with short M1 segments, and reside in older patients with sylvian fissures widened by brain atrophy.

Early surgery of multiple versus single aneurysms after subarachnoid hemorrhage: an increased risk for cerebral vasospasm?

OBJECT

As many as 33% of patients suffering from subarachnoid hemorrhage (SAH) present with multiple intracranial aneurysms (MIAs). It is believed that aneurysm surgery has the potential to increase the risk of cerebral vasospasm due to surgical manipulations of the parent vessels and brain tissue. Consequently, 1-stage surgery of MIAs, which usually takes longer and requires more manipulation, could even further increase the risk of vasospasm. The aim of this study is to define the correlation between vasospasm and the operative treatment of single intracranial aneurysms versus MIAs in a 1-stage operation.

METHODS

The authors analyzed a database including 1016 patients with SAH, identified retrospectively between 1989 and 1996 and prospectively collected between 1997 and 2004. Exclusion criteria were endovascular treatment, surgery after SAH Day 3, and, in patients with MIAs, undergoing more than 1 operation. Cerebral vasospasm was diagnosed by transcranial Doppler (TCD) ultrasonography and was defined as a maximum mean blood flow velocity > 120 cm/second. The diagnosis of symptomatic vasospasm was made if a new neurological deficit occurred that could not be explained by concomitant complications.

RESULTS

A total of 643 patients who experienced 810 aneurysms were included. Four hundred twenty-four patients were female (65.9%) and 219 were male (34.1%) with an average age of 53.1 years. One hundred twenty-one patients (18.8%) were diagnosed with MIAs. Maximum mean flow velocities measured by TCD were 131 cm/second in patients with MIAs and 129.5 cm/second in patients with single intracranial aneurysms. The incidence of TCD vasospasm (p = 0.561) as well as of symptomatic vasospasm (p = 0.241) was not significantly different in the 2 groups.

CONCLUSIONS

Clipping of more than 1 aneurysm in a 1-stage operation within 72 hours after SAH can be performed without increasing the risk of cerebral (TCD) vasospasm and symptomatic vasospasm.

OLFACTORY DYSFUNCTION AFTER IPSILATERAL AND CONTRALATERAL PTERIONAL APPROACHES FOR CEREBRAL ANEURYSMS

OBJECTIVE

This study investigated olfactory dysfunction after using a contralateral or ipsilateral pterional approach for anterior circulation aneurysms and related risk factors.

METHODS

This study included 189 patients who experienced an aneurysmal subarachnoid hemorrhage and in whom a pterional approach was used, including a contralateral pterional approach (12 patients), a pterional approach for an anterior communicating artery (AComA) aneurysm (70 patients), and an ipsilateral pterional approach for aneurysms of the anterior circulation, excluding the AComA (107 patients). In addition to questionnaires on olfactory function, Sniffin' Sticks tests were performed 12 to 38 months after the operation.

RESULTS

The incidence of olfactory dysfunction was high: 58% (7 of 12) with a contralateral pterional approach, 14% (10 of 70) with a pterional approach for an AComA aneurysm, and 4% (4 of 107) with an ipsilateral pterional approach for aneurysms of the anterior circulation, except for the AComA. In addition, patients 55 years and older had a higher incidence of olfactory dysfunction. Among the 12 patients in whom the contralateral pterional approach was used, 5 (42%) were anosmic and 2 (17%) were hyposmic. The incidence of olfactory dysfunction was also significantly higher at ages 55 years and older. The size and location of the contralateral aneurysm, if small (&lt;1 cm) and located within a 3-cm lateral distance from the midline, were not found to influence the incidence.

CONCLUSION

A higher incidence of olfactory dysfunction was found in those patients in whom a contralateral pterional approach and a pterional approach for an AComA aneurysm were used. Another major risk factor was an age of 55 years and older.

Microsurgical experience with supraorbital keyhole operations on anterior circulation aneurysms

OBJECTIVE

Conventional pterional approach is a commonly used neurosurgical technique for the treatment of cerebral aneurysms. However, this technique requires more extensive brain exposure than other key hole approaches and is sometimes associated with surgical traumatization or cosmetic problems. The aim of this study was to compare the postoperative outcome between pterional and supraorbital keyhole approaches in the patients with anterior circulation aneurysms.

METHODS

The authors reviewed patients with anterior circulation aneurysms who underwent aneurysm clipping via pterional or supraorbital keyhole approach at a single institute over a period of 2 years. Ninety-eight patients harboring 108 aneurysms were included in this study. Various outcomes were recorded, which included clinical grade, cosmetic problems, patients' satisfaction and complications such as chewing discomfort, frontal muscle weakness, hyposmia, infection.

RESULTS

The supraorbital approach exhibited a shorter operation time compared with the pterional approach. Complications such as chewing discomfort occurred less frequently in the supraorbital approach group. Moreover, the cosmetic outcome was significantly better in the supraorbital group than in the pterional group.

CONCLUSION

The supraorbital keyhole approach reduced intra- and postoperative complications, including chewing discomfort and cosmetic disturbances, compared with the conventional pterional approach.

Contralateral approach to a carotid bifurcation aneurysm in a case of multiple intracranial aneurysms: a case report

Background

Traditionally, surgery of the anterior circulation aneurysms of the cerebral vasculature is dictated by the site of the lesion, excluding such midline lesions as anterior communication artery aneurysms. Few reports address the issue of using a single craniotomy to obliterate multiple aneurysms located in both hemispheres.

Case presentation

A 51 year-old Caucasian right handed housewife lady (weight 61 kg, height 159 cm) presented with a headache of acute onset which proved to be caused by acute subarachnoid hemorrhage. Cerebral computed tomographic angiography revealed multiple aneurysms. The patient underwent a right pterional craniotomy to obliterate right middle cerebral, distal basilar and left carotid bifurcation aneurysms. The post-operative course was uneventful.

Conclusion

Despite technical difficulties of approaching cerebral vasculature through a contralateral craniotomy, this policy is advised in selected cases in which the benefits of unilateral craniotomy outweigh the risks of brain retraction.

Posterior projecting carotid-A1 junctional aneurysms

The authors report on two types of carotid-A(1) junctional aneurysms projecting backwards. In the two A(1)-type examples, the aneurysm originated at the posterior wall of the proximal A(1) joining the carotid termination and could be clipped using an ipsilateral pterional approach. However, in the carotid-type example, the aneurysm originated at the posterior wall of the carotid termination just below the A(1) origin, and required a contralateral pterional approach to expose the aneurysm. Although the carotid-A(1) junctional aneurysms are rare, their exact location and size can affect the side of the operative approach.

Microneurosurgical management of middle cerebral artery bifurcation aneurysms

BACKGROUND

Of the MCA aneurysms, those located at the main bifurcation of the MCA (MbifA) are by far the most frequent. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MbifAs.

METHODS

This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in southern and eastern Finland.

RESULTS

These 2 centers have treated more than 10,000 patients with intracranial aneurysm's since 1951. In the Kuopio Cerebral Aneurysm Data Base of 3005 patients with 4253 aneurysms, MbifAs formed 30% of all ruptured aneurysms, 36% of all unruptured aneurysms, 35% of all giant aneurysms, and 89% of all MCA aneurysms. Importantly, in 45%, rupture of MbifA caused an ICH.

CONCLUSIONS

Middle cerebral artery bifurcation aneurysms are often broad necked and may involve one or both branches of the bifurcation (M2s). The anatomical and hemodynamic features of MbifAs make them usually more favorable for microneurosurgical treatment. In population-based services, MbifAs are frequent targets of elective surgery (unruptured), acute surgery (ruptured), and emergency surgery (large ICH), even advanced approaches (giant). The challenge is to clip the neck adequately, without neck remnants, while preserving the bifurcational flow.

Unilateral pterional approach to bilateral aneurysms of the middle cerebral artery

BACKGROUND

The aim of the present study was to evaluate the technical viability of the unilateral pterional approach to simultaneously treat symmetrical bilateral aneurysm (mirror image) of the middle cerebral arteries (SBAMCA) and to determine the morbidity and mortality rates of this approach.

METHODS

Forty-six patients with SBAMCA underwent unilateral pterional craniotomy within a period of 9 years. Most patients were women (24, 80.0%) and mean age was 40.7 years.

RESULTS

Obliteration of the contralateral aneurysm was not possible in 16 patients (34.8%) because of brain edema in 8 patients operated on during the acute phase, lateral projection of the aneurysm in 3, a very long contralateral M1 segment in 4, and the presence of atheromatous plaques at the MCA bifurcation and aneurysm neck in 1. The remaining 30 patients (65.2%) were submitted to the proposed treatment. Final evaluation showed that 26 patients (86.7%) were Glasgow Outcome Scale (GOS) V, 1 patient (3.3%) was GOS IV, 2 patients (6.6%) were GOS III, and 1 patient (3.3%) was GOS I.

CONCLUSIONS

The unilateral pterional surgical approach to treat SBAMCA is a technically viable procedure associated with low morbidity and mortality. However, it requires a neurosurgeon experienced in cerebral aneurysm surgery and the appropriate technical conditions.

[Surgical treatment of múltiple intracraneal aneurysms]

INTRODUCTION

Surgical treatment of multiple intracranial aneurysms is always a complex task.

OBJECTIVE

To analyze aneurysms characteristics, therapeutic possibilities and surgical outcomes in a series of patients with multiple intracranial aneurysms.

PATIENTS AND METHOD

Among 514 patients with intracranial aneurysms, there were 113 with multiple aneurysms (21.5%) and 256 sacs: 244 located at the carotid system and 12 in the vertebrobasilar system. Patients were classified in three groups according to Orz criteria. Surgical treatment was performed in one or two stage operations. Patients were at I or II Grades of the World Federation Scale. The Glasgow Outcome Scale was used for evaluating surgical results.

RESULTS

Patients sacs rate was 2.3. The location of aneurysms was high in the posterior communicating artery and very low at the middle cerebral artery. 100% of the lesions in Orz group 1, 82% in group 2 and 33% in group 3 were operated on in one stage operation. Postoperative follow-up showed that 79 % of the patients made a completely recovery. Mortality rate was 4.4%.

CONCLUSIONS

Results were determined by the peculiar characteristics of this series, good preoperative condition and high proportion of one-stage operations.

Correlation of cephalic anthropometric parameters and microsurgical anatomy of the optic nerves: a cadaveric morphometric study

BACKGROUND

This study was designed to elucidate the possible correlation of cranial anthropometric measurements with the chiasm to limbus sphenoidale distance to facilitate preoperative estimation of this distance and to choose a better surgical approach.

METHODS

Thirty-three fresh adult cadaver heads (22 males and 11 females) were evaluated for cranial anthropometric measurements. The precraniotomy anthropometric measurements included (A) inion to nasion distance and (B) the longest intermeatal meridian. Subsequently, with a standard craniotomy, the following intervals were measured: (C) optic chiasm to falciform ligament, (D) anterior aspect of optic chiasm to limbus sphenoidale, and (E) limbus sphenoidale to inner nasion. A combined ratio parameter, labeled as (F), was calculated from the following equation: F = B/E x 10.

RESULTS

The mean values and standard errors of the mean of parameters A to F were 195.8 +/- 14.53 mm, 374.7 +/- 25.29 mm, 10.47 +/- 1.89 mm, 9.93 +/- 2.01 mm, 38.46 +/- 3.17 mm, and 9.81 +/- 1.11, respectively. The parameter D had significant correlation to the parameters B, C, E, and F. The most significant correlation was seen between parameters D and F (p < 0.001). According to linear regression assessment between parameters D and F, the following regression equation was obtained: D = 4.24 + 0.58F.

CONCLUSIONS

Optic nerve topography and dimensions show inter-personal variations that may be anticipated to some extent with cranial anthropometric data. Calculating of F ratio gives us an acceptable estimation of the actual distance of chiasm to limbus sphenoidale, which in turn can help the surgeon to select the approach to tumors of intrasellar region. However, the role of meticulous imaging studies cannot be overemphasized to confirm the anticipated estimations.

Progression of an arterial infundibulum to aneurysm: case report

In this case an aneurysm of the right posterior communicating artery developed 11 months after an infundibular dilation of this artery had been angiographycally and surgically demonstrated. In the best of the authors' knowledge, there are only eleven such cases reported in the literature. This report brings about diagnostic and therapeutic questions regarding arterial infundibula and the need of a better understanding of those lesions.

Bilateral supraorbital keyhole approach for multiple aneurysms via superciliary skin incisions

BACKGROUND

Considering that multiple aneurysms carry a high risk for fatal rupture, there is a need for complete treatment of all lesions in one surgical session using either unilateral-contralateral or bilateral approaches. Contralateral approaches have been used mainly for small anteriorly projecting middle cerebral and medially expanding ophthalmic types of aneurysms. They are limited by the narrow space for surgical manipulation, forced elevation of frontal lobes, and stretching of the olfactory nerves. These problems might result in damage to structures along the unusually long intracranial way of the approach. The complications associated with the unnecessarily large conventional fronto-temporal and bifrontal craniotomies, and the developments in visualization, neuroanaesthesia, microneurosurgery, cerebrospinal fluid (CSF) drainage, and brain protection have led to less invasive methods in cerebral base surgery. These achievements have supplied the background for the supraorbital keyhole approach to aneurysms of the anterior circulation or basilar tip. Because the supraorbital keyhole approach offers several advantages over the classic fronto-temporal craniotomies to the anterior skull base, it was extended for both sides in one surgical session to treat bilateral multiple aneurysms as well.

METHODS

Out of a series of 150 patients harboring 188 saccular aneurysms operated on via a supraorbital keyhole approach with a superciliar skin incision, 36 had multiple aneurysms. Thirty patients with multiple aneurysms underwent surgery for their ruptured aneurysms (17 cases in the acute phase and 13 patients during the chronic stage); in 6 cases silent aneurysms were operated on. The multiple aneurysms were managed from one side in 18 cases. A bilateral supraorbital keyhole approach was performed during one surgical session in 11 patients, and in 7 cases the unilateral supraorbital keyhole approach was combined with contralateral fronto-temporal (3 cases), suboccipital (2 cases), or frontal-parasagittal (2 cases) exploration. The operations were carried out through an approximately 2.5 x 3 cm supraorbital keyhole craniotomy following a skin incision just above the eyebrow. The roughly 4 cm superciliar skin incision begins medial to the supraorbital nerve and ends 3 to 10 mm beyond the lateral edge of the eyebrow. The technical details of the method are presented, and the benefits, limitations, and complications are discussed.

RESULTS

In the 36 patients operated on via the supraorbital keyhole approach 74 aneurysms were clipped successfully. In 2 cases premature intraoperative rupture of the aneurysms occurred, but these events were managed successfully. Despite the small size of the craniotomy the approach allows enough room for intracranial manipulation with maximal protection of the brain and other intracranial structures. One patient died because of pulmonary embolism. There were no craniotomy-related complications in the present series.

CONCLUSION

The supraorbital keyhole approach together with the advent of the modern neuroanaesthesia, CSF drainage, and microsurgical techniques is a safe approach in the hands of experienced neurosurgeons for the treatment of supratentorial or basilar tip aneurysms. Because the approach is simple and swift, the bilateral single-session craniotomy does not have any disadvantages compared to two-stage procedures. However, the one-sitting surgery reduces the high risk of fatal rupture in the perioperative period associated with multiple aneurysms.

Endoscope-assisted clipping of a superior hypophyseal artery aneurysm without removal of the anterior clinoid process. Case report

A 47-year-old man presented with a superior hypophyseal artery aneurysm and an ipsilateral posterior communicating artery aneurysm. Both lesions were successfully clipped without removal of the anterior clinoid process or retraction of the optic nerve by using endoscopic guidance. The endoscope was introduced into the prechiasmatic cistern and provided a clear visual field around the aneurysm that could not be seen via the operating microscope. The endoscope was useful in the identification of the medially projecting lesion and the small perforating branches of the ophthalmic segment of the internal carotid artery. A fenestrated clip could be introduced around the neck of the aneurysm and placed in the best position under endoscopic guidance. Endoscopy-assisted clipping is potentially a very useful procedure for aneurysm surgery.

Contralateral pterional approach to a giant internal carotid-ophthalmic artery aneruysm: technical case report

OBJECTIVE AND IMPORTANCE

The contralateral approach to internal carotid-ophthalmic artery aneurysms has been used in selected cases but has rarely been described for a giant internal carotid artery aneurysm. We report a case of giant aneurysm that was successfully clipped via the contralateral pterional approach.

CLINICAL PRESENTATION

A 69-year-old woman was found to have two aneurysms: a small aneurysm at the left internal carotid-posterior communicating artery and a giant aneurysm at the right internal carotid-ophthalmic artery.

INTERVENTION

A direct clipping operation was performed via the left pterional approach. After the small left internal carotid artery aneurysm was clipped, the contralateral giant aneurysm was further exposed and successfully clipped by use of the same approach via the prechiasmatic space.

CONCLUSION

The contralateral pterional approach can be applied even for a giant aneurysm of the carotid-ophthalmic artery aneurysm when the neck of the aneurysm is small and when there is a space between the anterior wall of the aneurysm and the tuberculum sellae. Furthermore, such a giant aneurysm can be clipped more easily and safely via the contralateral approach without compromising visual functions. To our knowledge, this is the first reported case of a giant internal carotid-ophthalmic artery aneurysm approached contralaterally. The feasibility of this approach can be assessed preoperatively by three-dimensional computed tomographic angiography as well as by conventional cerebral angiography.

Parameters for contralateral approach to ophthalmic segment aneurysms of the internal carotid artery

OBJECTIVE

This study was undertaken to define more accurately the feasibility and indications of the contralateral pterional approach to ophthalmic segment aneurysms of the internal carotid artery (ICA).

METHODS

Between 1995 and 1999, 46 patients with ophthalmic segment aneurysms of the ICA were surgically treated in our institution. Eleven of the 46 aneurysms were operated using the contralateral pterional approach. All aneurysms were successfully clipped without complications; three patients required bone resection around the aneurysm neck. We studied the 11 patients who were treated with the contralateral approach by defining six parameters to assess the feasibility of the approach and to predict the necessity for bone resection: 1) Parameter A, the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale; 2) Parameter B, the distance between the bilateral optic nerves at the entrance to the optic canal; 3) Parameter C, the interrelation of the optic nerve and the ICA, expressed as a/b in which a is the length from the midline to the optic nerve and b is the length from the midline to the ICA; 4) Parameter D, the size of the aneurysm neck; 5) Parameter E, the direction of the aneurysm from the ICA wall on the anteroposterior angiogram; and 6) Parameter F, the distance from the medial side of the estimated distal dural ring to the proximal aneurysm neck on the lateral angiogram.

RESULTS

Parameters A to F were 8.8 mm (range, 5.4-11.1 mm), 14.5 mm (range, 10.4-22.2 mm), 0.9 mm (range, 0.6-1.3 mm), and 3.0 mm (range, 2.3-4.7 mm), 5 to 160 degrees, and 1.3 mm (range, 0.3-2.4 mm), respectively. All patients had excellent operative outcomes without visual dysfunction. Three patients required drilling of the bone around the optic canal on the craniotomy side; bone drilling was not required when Parameter E was between 30 and 160 degrees and Parameter F was more than 1 mm.

CONCLUSION

Parameters A to D are important for assessing the feasibility of the contralateral approach to ICA-ophthalmic segment aneurysms, and Parameters E and F are most useful for calculating the difficulty of this approach.

Contralateral approach to junctional C2-C3 and proximal C4 aneurysms of the internal carotid artery: microsurgical anatomic study

OBJECTIVE

To evaluate a contralateral approach to aneurysms located in the internal carotid artery cave and proximal C4 segments.

METHODS

In six adult cadaveric head sides, proposed aneurysms in the carotid cave or proximal C4 segments were approached via contralateral craniotomies. We summarize the approach in the following steps: 1) frontotemporal orbital craniotomy, 2) drilling of the lateral sphenoid wing and opening of the dura along the frontotemporal base, 3) drilling of the planum sphenoidale and the tuberculum sellae more extensively toward the aneurysm side and opening of the sphenoid sinus, 4) drilling of the medial part of the anterior clinoid process on the side of the aneurysm and removal of the superior, medial, and inferior walls of the optic canal, 5) opening of the optic sleeve, and 6) opening of the space between the medial wall of the internal carotid artery C2-C3 segments and the lateral edge of the pituitary gland.

RESULTS

The contralateral approach to expose the opposite internal carotid artery cave and proximal C4 segments provided excellent views of the region, without mobilization or retraction of either the optic nerve or the carotid artery.

CONCLUSION

We recommend that this approach be used only for selected aneurysms, which are small and directed medially, anteriorly, or inferiorly, in the defined locations.

Endovascular treatment of multiple intracranial aneurysms by using Guglielmi detachable coils

OBJECT

The purpose of this paper is to present the authors' experience with Guglielmi detachable coil (GDC) embolization of multiple intracranial aneurysms and to evaluate the results of this therapy in single-stage procedures.

METHODS

Clinical and angiographic evaluations were performed in 38 consecutive patients with multiple intracranial aneurysms treated by GDC embolization between March 1990 and October 1997. Twenty-nine patients presented with subarachnoid hemorrhage (SAH), four with mass effect, and five were asymptomatic. These 38 patients harbored 101 aneurysms, 79 of which were treated with GDCs, 14 by surgical clipping, and eight were left untreated. Of the GDC-treated lesions, a complete endovascular occlusion was achieved in 55 aneurysms (70%), and 24 (30%) presented neck remnants. Twenty-five patients (66%) underwent GDC embolization of more than one aneurysm in the first session. Eighteen (86%) of 21 patients with acute SAH underwent treatment for all aneurysms within 3 days after admission (15 of 21 in one session). Follow-up angiographic studies in 30 patients demonstrated an unchanged or improved result in 94% of the aneurysms (59 lesions) and coil compaction in 6% (four lesions). The overall clinical outcome was excellent in 34 patients (89%), good in one (3%), fair in one (3%), and death in two (5%).

CONCLUSIONS

Endovascular treatment of multiple intracranial aneurysms, regardless of their location, with GDCs was performed safely in one session, even during the acute phase of SAH. Treatment of all aneurysms in one session protected the patient from rebleeding and eliminated the risk of mistakenly treating only the unruptured aneurysms.

Surgical outcome for multiple intracranial aneurysms

The surgical outcome of 221 cases with multiple intracranial aneurysms operated upon during the years 1988 to 1994 were reviewed. The patients were classified into three groups according to the locations of the aneurysms; group 1: multiple aneurysms located unilaterally in the anterior circulation only (147 cases); group 2: multiple aneurysms located bilaterally in the anterior circulation only (44 cases) and group 3: multiple aneurysms located in both anterior and posterior circulation or in the posterior circulation alone (30 cases). In 132 cases of group 1 (89.8%) all aneurysms were treated in one-stage operations. Twenty-eight patients from group 2 (63.6%) received partial treatment, where only the ruptured or the symptomatic aneurysms were treated. In 12 other cases from group 2 (27.3%) all multiple aneurysms were treated in two-stage operations. In group 3 patients, one-stage operations were performed in 18 cases (60%), while 9 patients (30%) received partial treatment only. Of the 221 multiple aneurysm cases, 162 (73.3%) presented with manifestations of subarachnoid haemorrhage (SAH). The remaining 59 multiple aneurysms cases (26.7%) presented with manifestations other than SAH (unruptured aneurysms). In the postoperative follow-up, of the 221 multiple aneurysms cases, 113 (51.1%) were free of neurological deficit (excellent), 48 cases (21.7%) were capable of leading an independent life (good), 32 cases (14.5%) were not independent and needed to be assisted (fair), and 28 patients (12.7%) died. These results were comparable to the results of patients with single aneurysms operated on during the same period. Based on our results, we recommend that whenever possible all multiple aneurysms should be treated in one-stage operations. In unruptured multiple aneurysm cases surgical management is the recommended treatment. In poor grade SAH patients or unruptured multiple aneurysms in old patients, two-stage operations or partial treatment of only the ruptured or the symptomatic aneurysms may be adopted.