Surgical outcome for multiple intracranial aneurysms

The clinical challenge of subarachnoid hemorrhage associated with multiple aneurysms when the bleeding source is not certainly identifiable

BACKGROUND

Multiple intracranial aneurysms (IAs) are encountered in 20-30% of the subarachnoid hemorrhages (SAH). Neuroimaging and clinical examination are usually sufficient to detect the bleeding source, but sometimes it can be misdiagnosed with catastrophic consequences.

METHODS

We reviewed our diagnostic work-up for all patients admitted from January 2016 to December 2020 for SAH with multiple IAs accounting for our rate of diagnostic failure. Then, we grouped the patients into 4 categories according to aneurysms topography and described our operative protocol in case of uncertain bleeding origin.

RESULTS

Sixty-two patients harboring 161 IAs were included. The bleeding source was identified in 56 patients (90.3%), who harbored other 81 bystander aneurysms. In 6 cases (9.7%) with a total of 24 aneurysms we failed the bleeding source identification. According to IAs topography, we grouped the IAs multiplicity in: 1) anterior plus posterior circulation IAs; 2) multiple posterior circulation IAs; 3) bilateral anterior circulation IAs; and 4) multiple ipsilateral anterior circulation IAs. In case of unidentified bleeding source, key-elements favoring the simultaneous multiple IAs treatment were their number, morphology, topography, clinicians' experience, and management modality as endovascular treatment allows a faster exclusion of multiple IAs distant one each other compared with surgery. MCA involvement represented the more frequent reason to prefer multiple clipping rather than multiple coiling.

CONCLUSIONS

In a small percentage of patients with SAH with multiple IAs, bleeding source identification can be difficult. Until the routinely availability of new tools such as vessel wall imaging or computational fluid dynamics, an experienced neurovascular team and strategies aiming to simultaneously exclude multiple IAs remain mandatory.

Single flow diverter to manage multiple intracranial aneurysms in a parent artery

BACKGROUND

Endovascular coil embolization has become an important method in the management of intracranial aneurysm. However, simultaneously coiling multiple intracranial aneurysms (MIAs) in unilateral parent artery in one-stage may fail or insufficient in geographic difficult aneurysm. Flow diverter (FD) has the potential to manage MIAs with nonamenable to coiling. Herein, we report periprocedural morphologic change and outcomes using single FD to manage unruptured MIAs in a parent artery.

METHODS

Over a 3-year period, a total of 63 patients with 126 MIAs successful managed by single FD with complete angiographic follow-up. There were 49 women and 14 men, with ages ranging from 42 to 77 years (mean: 59 years). We retrospectively assessed the clinical data, aneurysm characteristic, angiographic and clinical outcomes of all patients and compared with 171 patients with single aneurysm managed by FD.

RESULTS

Sixty-one patients with 118 aneurysms (94%) located in internal carotid artery or middle cerebral artery (n = 4, 3%), two patients with four aneurysms (4%) were found in the basilar artery. The mean aneurysm size was 5.6 mm (range from 1.8 to 38 mm). Mean angiographic follow-up was 14 months. Complete obliteration of aneurysm was achieved in 102 aneurysms (83%), subtotal or partial aneurysm obliteration was demonstrated in 18 aneurysms (15%), unchanged aneurysm morphology in three (2%). Aneurysm morphology synchronized alteration in 55 patients (87%), other eight patients (13%) with 16 aneurysms showed different morphologic alteration in angiographic follow-up. Four patients (6.3%) had intraprocedural ischemic complication. During the follow-up period, 61 patients (97%) were neurologic stable; there was no hemorrhagic or ischemic event.

CONCLUSION

Single FD was feasible to treat MIAs in a parent artery with both effective and safe in one-stage management. Most aneurysms synchronized alteration of morphology in a mid-term follow-up. The procedure was almost the same with FD managing single aneurysm, but longer FD is needed in MIAs.

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.

Timing and outcome of bystanders treatment in patients with subarachnoid hemorrhage associated with multiple aneurysms

In case of subarachnoid hemorrhage (SAH) associated with multiple intracranial aneurysms (MIAs), the main goal of acute treatment is securing the source of bleeding (index aneurysm). Indications and timing of bystanders treatment are instead still debated as the risk of new SAHs in patients harboring MIAs is not yet established. However, even if technically feasible, a simultaneous management of all aneurysms remains questionable, especially for safety issues. We retrospectively reviewed our last 5-year experience with SAH patients harboring MIAs entered in a clinic-radiological monitoring for bystanders follow-up in order to evaluate the occurrence of morphological changes, bleeding events, and safety and efficacy of a delayed treatment. We included 39 patients with mean age of 59.5 ± 12.2 years who survived a SAH. Among them, 14 underwent treatment, whereas 25 continued follow-up. The mean time between index and bystanders treatment was 14.3 ± 19.2 months. Patients undergoing bystanders treatment were mainly female and in general younger than patients undergoing observation. No cases of growth or bleeding were observed among bystanders within the two groups during the follow-up, which was longer than 1 year for the intervention group, and almost 40 months for the observation group. No major complications and mRS modifications were observed after bystanders treatment. Our data seem to suggest that within the short follow-up, intervention and observation seem to be likewise safe for bystander aneurysms, showing at the same time that a delayed management presents a similar risk profile of treating unruptured aneurysms in patients with no previous history of SAH.

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.

HYBRID MICROSURGICAL AND ENDOVASCULAR APPROACH IN THE TREATMENT OF MULTIPLE CEREBRAL ANEURYSMS: AN ILLUSTRATIVE CASE SERIES IN CORRELATION WITH LITERATURE DATA

Contemporary cerebral aneurysm treatment has advanced due to the expansion of microsurgical and endovascular techniques having different advantages and restraints. However, some aneurysms cannot be effectively treated by a single method alone due to their specific anatomy, location, complexity, and/or multiplicity. Subsequently, multiple aneurysms sometimes necessitate a hybrid strategy integrating both methods. The study aims were to discuss indications, possibilities, and challenges of a hybrid strategy in the decision making and treatment of multiple intracranial aneurysms. A single-institution illustrative case series of multiple intracranial aneurysm patients treated by a hybrid approach was analyzed and management outcome discussed and correlated with literature data. Following the treatment, both patients from our case series recovered well, having complete and stable aneurysmal occlusion with no relapse and no postoperative procedure-related complications or long-lasting neurological symptoms. In conclusion, a hybrid approach is advised as a treatment option for multiple cerebral aneurysms when a single modality is insufficient to bring satisfactory results. It may be a suitable and safe addition to an assortment of treatments pledging clinical improvement and enabling positive management outcome in patients with ruptured and non-ruptured multiple cerebral aneurysms.

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.

Outcome of Microsurgical Clipping for Multiple Versus Single Intracranial Aneurysms: A Single-Institution Retrospective Comparative Cohort Study

OBJECTIVE

To evaluate the results of microsurgical clipping for single intracranial aneurysm (SIA) and multiple intracranial aneurysms (MIA) and compare the outcomes.

METHODS

All patients who underwent surgery for intracranial aneurysm (IA) at our institution over a 3-year period (June 2013 to May 2016) were included in this study.

RESULTS

A total of 157 patients with 225 IAs were included. Forty-one of these patients had MIA (109 IAs, mean, 2.7 ± 1.2; range, 2-7), and remaining 116 had SIA. In the patients with MIA, all aneurysms were secured during the same admission whenever possible. Depending on the locations of the IAs and condition of brain during surgery (tense/lax), all aneurysms were secured on same day (in a single session, single or multiple craniotomy in 28 patients) or on different days (multiple sessions in 13 patients). Postoperative control angiography (DSA) before discharge could be done for 216 aneurysms (MIA, n = 105; SIA, n = 111). Successful occlusion of the aneurysm from circulation was noted in 96.2% (101/105) of MIA and 93.7% (104/111) of SIA. Follow-up of 6 months or longer was available for 146 patients. A modified Rankin Scale score ≤2 was considered a good outcome. Univariate analysis of the entire group revealed no significant difference in clinical outcomes between patients with SIA and MIA both at discharge (good outcome: MIA, 82.9%; SIA, 93.1%; P = 0.068) and at a final follow-up of ≥6 months (good outcome: MIA, 87.2%; SIA, 94.4%; P = 0.164). Clipping for MIA was not associated with poor outcome in multivariate analysis.

CONCLUSIONS

Comparable clinical outcomes and high rates of complete aneurysm occlusion following microsurgical clipping can be expected in patients with SIA and patients with MIA.

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.

Accuracy in Identifying the Source of Subarachnoid Hemorrhage in the Setting of Multiple Intracranial Aneurysms

BACKGROUND

Subarachnoid hemorrhage cases with multiple cerebral aneurysms frequently demonstrate a hemorrhage pattern that does not definitively delineate the source aneurysm. In these cases, rupture site is ascertained from angiographic features of the aneurysm such as size, morphology, and location.

OBJECTIVE

To examine the frequency with which such features lead to misidentification of the ruptured aneurysm.

METHODS : Records of patients who underwent surgical clipping of a ruptured aneurysm at our institution between 2004 and 2014 and had multiple aneurysms were retrospectively reviewed. A blinded neuroendovascular surgeon provided the rupture source based on the initial head computed tomography scans and digital subtraction angiography images. Operative reports were then assessed to confirm or refute the imaging-based determination of the rupture source.

RESULTS

One hundred fifty-one patients had multiple aneurysms. Seventy-one patients had definitive hemorrhage patterns on initial computed tomography scans and 80 patients had nondefinitive hemorrhage patterns. Thirteen (16.2%) of the cases with nondefinitive hemorrhage patterns had discordance between the imaging-based determination of the rupture source and intraoperative findings of the true ruptured aneurysm, yielding an imperfect positive predictive value of 83.8%. Of all multiple aneurysm cases with subarachnoid hemorrhage treated by surgical or endovascular means at our institution, 4.3% (13 of 303) were misidentified.

CONCLUSION

Morphological features cannot reliably be used to determine rupture site in cases with nondefinitive subarachnoid hemorrhage patterns. Microsurgical clipping, confirming obliteration of the ruptured lesion, may be preferentially indicated in these patients unless, alternatively, all lesions can be contemporaneously and safely treated with endovascular embolization.

Influence of morphology and hemodynamic factors on rupture of multiple intracranial aneurysms: matched-pairs of ruptured-unruptured aneurysms located unilaterally on the anterior circulation

BACKGROUND

The authors evaluated the impact of morphological and hemodynamic factors on the rupture of matched-pairs of ruptured-unruptured intracranial aneurysms on one patient's ipsilateral anterior circulation with 3D reconstruction model and computational fluid dynamic method simulation.

METHODS

20 patients with intracranial aneurysms pairs on the same-side of anterior circulation but with different rupture status were retrospectively collected. Each pair was divided into ruptured-unruptured group. Patient-specific models based on their 3D-DSA images were constructed and analyzed. The relative locations, morphologic and hemodynamic factors of these two groups were compared.

RESULTS

There was no significant difference in the relative bleeding location. The morphological factors analysis found that the ruptured aneurysms more often had irregular shape and had significantly higher maximum height and aspect ratio. The hemodynamic factors analysis found lower minimum wall shear stress (WSSmin) and more low-wall shear stress-area (LSA) in the ruptured aneurysms than that of the unruptured ones. The ruptured aneurysms more often had WSSmin on the dome.

CONCLUSIONS

Intracranial aneurysms pairs with different rupture status on unilateral side of anterior circulation may be a good disease model to investigate possible characteristics linked to rupture independent of patient characteristics. Irregular shape, larger size, higher aspect ratio, lower WSSmin and more LSA may indicate a higher risk for their rupture.

Multiple intracranial aneurysms: endovascular treatment and complications

This study evaluated the results of endovascular embolization of multiple intracranial aneurysms. A retrospective hospital chart and radiograph review were made of all patients with multiple intracranial aneurysms seen between March 2010 and January 2011. Ten patients presented with subarachnoid hemorrhage, four with mass effect, two with brain ischemia and twenty were incidental. These 36 patients harbored 84 aneurysms, 63 of which were treated with endovascular techniques, two by surgical clipping, and 19 were left untreated. Of the coil-treated lesions, a complete endovascular occlusion was achieved in 54 aneurysms (85.7%), and eight (12.7%) presented neck remnants with one (1.6%) stented only. Twenty-six patients (72.2%) underwent coil embolization of more than one aneurysm in the first session. Follow-up angiographic studies in 31 patients demonstrated an unchanged or improved result in 93.0% of the aneurysms (53 lesions) and coil compaction in 7.0% (four lesions). The overall clinical outcome was excellent in 33 patients (91.7%), good in one (2.8%) and fair in two (5.5%). Endovascular techniques may be a particularly suitable method for treating multiple intracranial aneurysms.

Clip ligation of unruptured intracranial aneurysms: a prospective midterm outcome study

BACKGROUND

We conducted a prospective study to investigate the clinical and radiological outcome in a surgical case series of 176 patients with 203 unruptured intracranial aneurysms (UIA).

METHODS

The success of aneurysm obliteration was assessed within 2 weeks after surgery by digital subtraction angiography (DSA). Patients also underwent angiography 5 years after surgery. Clinical outcomes were assessed using the modified Rankin Scale (mRS). All predictors of poor surgical outcomes were assessed using an exact logistic regression.

RESULTS

Overall, 83 % of the patients had a good outcome (mRS score 0 or 1); 10.8 % of the patients had a slight disability (mRS score 2), and 6.2 % of the patients had a moderate or moderate-severe disability (mRS score 3 or 4). The mortality rate was 0 % overall. The most important predictors of outcome were presence of history of ischemic cerebrovascular disease and postoperative stroke. Complete aneurysm occlusion was achieved in 93.5 % of all aneurysms. Sixty percent of treated aneurysms were checked with late follow-up DSA. No cases of hemorrhage from a surgically obliterated UIA were documented in this series during the 7.3 ± 1.4 (SD)-year follow-up period.

CONCLUSIONS

If patients are carefully selected and individually assigned to their optimum treatment modality, IUAs can be obliterated by surgery with a low percentage of unfavorable outcomes.

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.

Hemodynamics of small aneurysm pairs at the internal carotid artery

Cerebral aneurysms carry significant risks because rupture-related subarachnoid hemorrhage leads to serious and often fatal consequences. The rupture risk increases considerably for multiple aneurysms. Multiple aneurysms can grow from the same location of an artery, and the interaction between these aneurysms raises the rupture risk even higher. Four aneurysm pair cases at the internal carotid artery are investigated for their hemodynamic behaviors using patient-specific modeling. For each case, aneurysms are separated from the parent artery and three models are reconstructed, one with two aneurysms and the other two models with only one of the two aneurysms. Results show that the relative anatomic location of one aneurysm to the other may determine the hemodynamic environment of an aneurysm. The presence of a proximal aneurysm reduces the intra-aneurysmal flow into the distal aneurysm; the proximal aneurysm and larger aneurysm have a greater area under low wall shear stress. The average intra-aneurysmal inflow ratio ranges from 16% to 41%, and reduction of the inflow ratio by an aneurysm pair varies from 6% to 15%. The maximum wall shear stress increases for serial aneurysms, but decreases for parallel aneurysms. Interaction between parallel aneurysms is not significant; however, the proximal aneurysm in serial aneurysms may be subject to a greater rupture risk.

Management of ruptured aneurysms combined with coexisting aneurysms

In patients suffering from subarachnoid haemorrhage (SAH) and presenting with multiple intracranial aneurysms (MIA) two questions have to be decided on: 1st when is the ideal moment to eliminate the ruptured aneurysm and 2nd when to treat the coexisting aneurysms. In our series we retrospectively analysed 124 SAH-patients presenting with a total of 323 aneurysms. In 57 patients the ruptured aneurysm and all coexisting aneurysms were clipped during the first operation, whereas in 9 patients only some of the coexisting aneurysms (group-A; age in median 55 years) were clipped besides the ruptured one. In 55 patients (group-B; age in median 55 years) the first operation was restricted to clipping the ruptured aneurysm, dealing with the coexisting aneurysm subsequently. Immediately after admission 3 patients passed away. One of the 64 patients waiting (average 60 days, median 14 days) for the subsequent clipping of the not yet secured aneurysms suffered a SAH. Six to 12 months after the initial SAH, 78% of the cases in both groups reached a Glasgow Outcome Score of 4 or 5. Even if in patients with coexisting unruptured intracranial aneurysms the elimination of each and every aneurysm is recommended, the advantages of an unstaged procedure versus the additional strain caused by the prolongation of the procedure, e.g. approach over the midline, 2 or more craniotomies, and the risk of additional ischemic damage to the brain, caused by increased manipulation of cerebral arteries and brain tissue, have to be carefully considered. This is of special importance in dealing with patients in higher Hunt and Hess grades.

Multiple intracranial aneurysms. Angiographic study and endovascular treatment

SUMMARY

We evaluate endovascular treatment (EVT) as an option to deal with multiple intracranial aneurysms(MA). From 1994 to 2001, 24 patients underwent EVT for 59 MA. Patients were followed- up clinically and angiographically in a period ranging from 6 to 93 months (mean time of 22.2) and from 4 to 69 months (mean time of 19.3), respectively. Ten patients (41.6%) were treated either by EVT (n=7, 29,16%) or by mixed treatment (EVT and surgery; n=3, 12.5%). Reasons for treating just ruptured aneurysms: six (25%) had aneurysms smaller than 5 mm; three (12.5%) deaths; two (8.33%) were in the subacute period; two (8.33%) lost to follow-up; one (4.17%) authorised no procedure. No rebleeding was detected at the clinical follow-up, but there were five deaths.At immediate arteriographic control: 28 (85%) aneurysms were fully occluded, four (12%) with neck flow and one (03%) with sac flow. For 20 aneurysms followed-up: stability of occlusion was reached in seven cases (35%) and repermeabilization in 13 (65%). Management of recanalization was close arteriography in seven (54%), re-embolization in five (38%) and surgery in one (08%). When treating MA, EVT is advisable either alone or in mixed therapy. As a high degree of repermeabilization was disclosed, strict arteriographic control is required. The mechanisms underlying aneurysmal formation may be also involved in the recanalization phenomenon , a possible new manifestation of the fragility of the arterial wall.

[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.

[Multiple cerebral aneurysms]

BACKGROUND

To define risk factors for the multiplicity of cerebral aneurysms, as well as clinical and therapeutical characteristics of patients with single aneurysms (SA) and multiple aneurysms (MA).

METHODS

Retrospective study on 95 patients with SA and 22 patients with MA. For patients with SA and MA the following parameters were compared: gender, age, clinical state, aneurysmal localization and size, incidence of rebleeding and vasospasm, manner and outcome of treatment, preoperative interval, intraoperative rupture and postoperative complications.

RESULTS

Aneurysms on anterior communicating artery existed in 37.4% of SA and in 17.8% of all MA (p < 0.05). As much as 44.2% of all aneurysms on middle cerebral artery and only 19% of all aneurysms on anterior communicating artery were associated with some other aneurysm (p < 0.02). The average size of SA was 15.4 +/- 11.8 mm, and 9.8 +/- 9 mm for MA (p < 0.05). Surgery was performed in 77.3% of patients with MA and 78.9% of patients with SA (p > 0.05), but complete surgical clipping was performed in 89.3% of patients with SA and in 47.1% of patients with MA (p < 0.01). Among operated patients with MA and SA, intraoperative rupture occurred in 36% and 17.6% of cases, respectively (p < 0.05) and ischemic postoperative complications were found in 29.4% and 17.3% of the cases (p > 0.05). Among 72.7% of all patients with MA and in 69.5% of all patients with SA the outcome was good, while among surgically treated patients it was good in 76.5% and 70.7% of cases, respectively.

CONCLUSION

The treatment outcome was similar for patients with MA and SA, but complete operative treatment is significantly more frequent for SA. Multiple aneurysms were considerably smaller and with different anatomical distribution in relation to solitary aneurysms.

The surgical management of contralateral anterior circulation intracranial aneurysms

This study reviews the surgical management of contralateral anterior circulation aneurysms in patients with bilateral intracranial aneurysms repaired following a unilateral craniotomy. Between 1993 and 1999, 27 patients had 88 intracranial aneurysms repaired. Eleven patients presented following subarachnoid haemorrhage. Excluding midline aneurysms, 31 anterior circulation aneurysms were contralateral to the craniotomy and all were repaired at the same time that ipsilateral or midline aneurysms were repaired. Morbidity included one death and one case of loss of unilateral vision directly attributable to surgery and two cases of cerebral infarction due to vasospasm. No new neurological deficit or mortality could be directly attributed to the repair of a contralateral aneurysm. The repair of all accessible aneurysms, including those contralateral to the craniotomy, during one session avoids the risk of haemorrhage from incidental or unrecognised ruptured aneurysms (particularly during the aggressive treatment of vasospasm), avoids a second craniotomy, decreases overall hospitalisation and can improve visualisation of carotid-ophthalmic aneurysms.

Functional outcome after repair of unruptured intracranial aneurysms

OBJECT

Repair of unruptured aneurysms is a reasonable course of action if their expected natural history is worse than the predicted risks of treatment. The purpose of this study was to examine the presenting symptoms of unruptured aneurysms and to test the hypothesis that unruptured intracranial aneurysms can be repaired without significant functional worsening. A second hypothesis was also examined--that is, that the experience of the surgeon, the aneurysm size, and the patient age can be used to predict functional outcome.

METHODS

Consecutive patients who underwent repair of an unruptured intracranial aneurysm at a single institution between 1980 and 1998 were studied. Clinical and radiographic data were collected in all patients. Their modified Rankin Scale (mRS) score was determined before treatment (baseline), at 6 weeks, and at 6 months. The primary endpoint for analysis was the mRS score. Four hundred forty-nine aneurysms were repaired in 366 patients by 10 surgeons. The mean size of the primary lesion repaired was 14.6 + 10.4 mm and 27% were judged to be symptomatic. Aneurysm treatment involved either microsurgical clipping (78%), wrapping (4%), trapping with or without bypass (5%), hunterian ligation with or without bypass (9%), or other methods (4%). The mRS scores at 6 weeks were worse than at baseline (p < 0.0001), but there was no significant difference between the baseline and 6-month mRS score. At 6 months, 94% of patients showed no significant functional worsening as a result of treatment. The number of aneurysms treated by a specific surgeon was a strong predictor of better functional outcome (r = 0.99, p = 0.05). Increasing patient age (r = 0.16, p = 0.003) and increasing aneurysm size (r = 0.15, p = 0.004) were predictors of worsened functional outcome.

CONCLUSIONS

Many unruptured aneurysms produce symptoms. Unruptured intracranial aneurysms can be treated without significant permanent functional worsening. The surgeon's experience, aneurysm size, and patient age are predictors of functional outcome.

Double aneurysms at distal basilar artery: report of nine cases

OBJECTIVE

Double aneurysms at the basilar bifurcation and the basilar artery-superior cerebellar artery (BA-SCA) junction have not been well investigated previously. We analyzed nine patients with double basilar aneurysms to evaluate their radiological characteristics and suitable treatment.

METHODS

Between 1978 and 1999, the incidence of double aneurysms was 5.3% in our 169 consecutive surgical cases of distal BA aneurysms. Seven (77.8%) of the nine patients with double aneurysms had associated aneurysms in the anterior circulation. Open surgery was performed in eight patients and coil embolization in one. The patients' radiological findings, choice of treatment, and surgical results were analyzed retrospectively.

RESULTS

The size of the basilar bifurcation aneurysms ranged from 2 to 8 mm (mean, 4.4+/-2.0 mm), and the size of the BA-SCA aneurysms ranged from 2 to 12 mm (mean, 5.6+/-3.6 mm). Diagnosis of double basilar aneurysms was difficult when the basilar trunk had twisted or when size differences between the two aneurysms were apparent. The angle between the posterior cerebral artery and SCA appeared to be wider on the same side as the BA-SCA aneurysms (101+/-42 degrees) than on the opposite side (26+/-24 degrees). The P1 segment of the posterior cerebral artery originated in an upright direction from the basilar bifurcation between the two basilar aneurysms in seven patients. The pterional approach was used in eight patients; 14 basilar aneurysms were successfully clipped and 2 were wrapped. Nonstraight clips with short blades were used frequently. Coil embolization of double aneurysms was required twice in one patient because the initial angiogram was misinterpreted as a single aneurysm and its bleb.

CONCLUSION

Measurement of the posterior cerebral artery-SCA angle is a simple method to estimate the presence of BA-SCA aneurysms and to differentiate double aneurysms from a bilocular aneurysm at the basilar bifurcation. The pterional approach is suitable for clipping double basilar aneurysms because anterior circulation aneurysms often coexist, and the upstanding P1 segment is an obstacle in the subtemporal approach to the basilar bifurcation aneurysm. Nonstraight clips with short blades are convenient to avoid conflicting clips in the narrow surgical space.

False localization of rupture site in patients with multiple cerebral aneurysms and subarachnoid hemorrhage

OBJECTIVE

Patients with subarachnoid hemorrhage and multiple intracranial aneurysms present a unique challenge to the neurosurgeon. Unless all aneurysms can be clipped through a single craniotomy, the surgeon must accurately determine which aneurysm has ruptured. Misjudgment may result in disastrous postoperative rebleeding from the untreated but true ruptured lesion. We assessed the risk of false localization of the rupture site and subsequent rebleeding and documented the problems in predicting the true rupture site when patients have multiple intracranial aneurysms.

METHOD

We reviewed the records of a consecutive series of 93 patients treated over a period of 12 years who presented with their first subarachnoid hemorrhage and who had multiple intracranial aneurysms. The rupture site was determined on the basis of computed tomographic and angiographic findings, and the supposed ruptured aneurysm was clipped within 2 days of hemorrhage in each patient. Additional aneurysms that could not be accessed in the same surgical session were operated on at a later stage. All patients' records were reviewed, and all computed tomographic scans and angiograms, including repeat studies performed in some patients, were retrospectively reevaluated by the authors, who had no knowledge of the patients' clinical information.

RESULTS

The location of the aneurysm that ruptured was verified at the time of surgery or during the autopsy in 76 patients (82%). The aneurysm that ruptured was the one predicted as ruptured by the surgeon before surgery in 69 patients (91%) and in retrospect in 72 patients (95%). Five of the 6 patients in whom the ruptured aneurysm was not correctly identified were thought to have only a single aneurysm. Four patients rebled after surgery, and 2 patients died as a result of the rebleeding.

CONCLUSION

In the reported series, the most common cause of rebleeding soon after aneurysm surgery was failure to obliterate the ruptured aneurysm, usually because it was missed on the initial angiogram. The results support not only meticulous radiological investigation of all intracranial arteries before surgery but also thorough surgical inspection of the target aneurysm in all cases of subarachnoid hemorrhage even after one candidate lesion has been discovered.

Risks of surgery for patients with unruptured intracranial aneurysms

BACKGROUND

With the widespread use of less invasive imaging tools, such as magnetic resonance angiography and computed tomographic angiography, unruptured cerebral aneurysms are found much more often than in the past. This retrospective study was undertaken to determine the risk factors for surgical intervention in a patient with an unruptured intracranial aneurysm.

METHODS

Over a 5-year period, 1,558 patients with intracranial aneurysms underwent surgery at our center. Of these, 310 patients (20%) with unruptured aneurysms were included in this study.

RESULTS

Out of 310 patients with unruptured aneurysms, 292 (95%) had a favorable outcome, and only one patient (0.3%) with a giant vertebral artery aneurysm died. Aneurysm size larger than 15 mm and location of the aneurysm in the posterior circulation were independent risk factors associated with less favorable outcomes. Patients with a single aneurysm had a better outcome than did patients with multiple aneurysms.

CONCLUSION

Our results support the contention that surgical treatment of unruptured intracranial aneurysms carries a low risk of morbidity and mortality and may improve the outcome in patients harboring cerebral aneurysms by preventing the devastating effects of subarachnoid hemorrhage. Aneurysm size, location, and number were risk predictors for surgical morbidity in patients with unruptured aneurysms.

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.

Mortality and morbidity of surgery for unruptured intracranial aneurysms: a meta-analysis

BACKGROUND AND PURPOSE

Greater availability and improvement of neuroradiological techniques have resulted in more frequent detection of unruptured aneurysms. Because prognosis of subarachnoid hemorrhage is still poor, preventive surgery is increasingly considered as a therapeutic option. Elective surgery requires reliable data on its risks. Therefore, we performed a meta-analysis on the mortality and morbidity of surgery for unruptured intracranial aneurysms.

METHODS

Through Medline and additional searches by hand, we retrieved studies on clipping of unruptured (additional, symptomatic, or incidental) aneurysms published from 1966 through June 1996. Two authors independently extracted data. We used weighted linear regression for data analysis.

RESULTS

We included 61 studies that involved 2460 patients (57% female; mean age, 50 years) and at least 2568 unruptured aneurysms (27% >25 mm, 30% located in the posterior circulation). Mortality was 2.6% (95% confidence interval [CI], 2.0% to 3.3%). Permanent morbidity occurred in 10.9% (95% CI, 9.6% to 12.2%) of patients. Postoperative mortality was significantly lower in more recent years for nongiant aneurysms and aneurysms with an anterior location; the last 2 characteristics were also associated with a significantly lower morbidity.

CONCLUSIONS

In studies published between 1966 and 1996 on clipping of unruptured aneurysms, mortality was 2.6% and morbidity was 10.9%. In calculating the pros and cons of preventive surgery, these proportions should be taken into account.

Aneurysm size: a prognostic factor for rupture

For effective management of patients with unruptured intracranial aneurysms, prognostic criteria for rupture are needed, of which aneurysm size is a key factor. However, the critical size at which an aneurysm becomes hazardous is not known. During the last 5 years, 1558 aneurysm patients have been operated on in our centre. Of these 1248 presented with a subarachnoid haemorrhage (ruptured aneurysms) and 310 without a subarachnoid haemorrhage (unruptured aneurysms). Of the ruptured aneurysms 475 (38%) were small in size with a maximum diameter < 6 mm. Most of these small ruptured aneurysms were located on the anterior communicating artery. Of the 310 patients with unruptured aneurysms 253 (81.6%) had single aneurysms; 113 (44.7%) of those were small in size. Most of these small unruptured aneurysms were located on the middle cerebral artery. The remaining 57 patients with unruptured aneurysms harboured multiple aneurysms totalling 116 aneurysms; 50% of them were small in size. Our of 160 patients with multiple aneurysms presenting with subarachnoid haemorrhage, 34 patients had small aneurysm(s) accompanied with medium or large sized aneurysm(s); in nine (26.5%) of these 34 patients the small aneurysm was the ruptured one. These data suggest that small aneurysms < 6 mm in diameter are not innocuous and hazardous, and surgical treatment should be considered for small unruptured aneurysms even if they are less than 6 mm in diameter.