**8. Clipping of multiple aneurysms**

In the Western population, it is estimated that 10–13% of patients with IAs possess MIAs, and it is sometimes difficult to find the source of SAH, but even more so to treat each lesion [70, 111–114]. A number of cases have been correlated with either congenital or chronic disorders such as Gaucher's disease, Fahr's disease, or Behcet's disease, although whether there is an etiologic correlation or merely a diagnostic coincidence is unknown [115–118]. Mirror aneurysms denote a rare condition in which the multiple aneurysms are placed symmetrically in the cerebral hemispheres. The most common sites are the non-cavernous segments of the ICAs [119, 120]. Mirror aneurysms also display a decreased propensity to rupture and improved outcomes than non-mirror aneurysms. Certain risk factors such as female gender (which also strongly influences the number of IAs), advanced age, smoking, uncontrolled hypertension, and increased body mass have been linked to a heightened chance of developing MIA [121, 122]. However, due to contradictory and inconclusive results, it is currently unknown whether the presence of MIAs implies a greater risk of rupture than that of single IAs [122]. Aneurysm morphology and size are thought to play the most important roles in the risk of rupture [91, 70]. Apparently, endovascular procedures lead to fewer neurologic complications than surgical clipping; however clipping yields higher occlusion rates, fewer total complications, and angiographic recurrence [69]. In theory, hemodynamic alterations occurring in an untreated distal UIA after the treatment of a proximal IA might

**161**

*Preventing Rupture: Clipping of Unruptured Intracranial Aneurysms*

other IAs, it is easier to control bleeding on this side.

compensate for the expenses of two easier interventions (**Figure 4**).

**9. Aneurysm clipping in elderly**

increase the risk of bleeding, underlying the necessity of treating all aneurysms simultaneously and by any means [66]. It is sometimes feasible to treat all aneurysms at the same time during the same sitting and using the same craniotomy, thus lowering hospital stay, surgical exposure, and risk of complications [119, 123–125]. We support the classical pterional approach for tackling multiple aneurysms of the anterior circulation in the same opening. It offers a wide enough opening to approach even the aneurysms of the M1 segment on the opposite side. This is mostly useful for selected patients with simple contralateral UIA with narrow necks and which project inferiorly or anteriorly [119, 123]. The craniotomy should be performed on the side of the most complex aneurysm, or the one which has ruptured. On one hand, this methodology provides the highest visibility of the aneurysm and shortest distance to the dome and hematoma in case of bleeding. On the other hand, because of the hemodynamic changes that might occur during the clipping of the

Clipping the contralateral aneurysms first may prevent a complicated and hard to manage bleeding on this side. After that, clipping the aneurysms more proximal to the surgeon can be performed. There are, however, some drawbacks to this technique [123, 126]. Firstly, it implies a heightened brain retraction compared to that of the same-side craniotomy, yet this can be managed by adequate brain relaxation. The maneuverability is lower, and the vision is reduced on the opposite side. However, a larger craniotomy, wider arachnoid dissection, and brain relaxation can aid in this situation. Contralateral MCA bifurcation and PCoA aneurysms are more difficult to find and clip, requiring maneuvering around thin perforators and fragile veins. Hemostasis is not as easy on the distal side in the case of rupture, which is why these IAs should be clipped first. Lastly, this technique requires an experienced vascular neurosurgical team; however, surgical simulation with 3D reconstructions may alleviate results [127]. However, this surgery should only be performed in selected cases, as the risks associated with a single challenging surgery do not

From our operative experience, we contraindicate performing two surgeries on two separate days, as the risk of rupture of the remaining untreated UIAs during this interval is not negligible. If a single opening is not indicated, we recommend approaching the more complex aneurysms first through one craniotomy, and afterward, during the same anesthesia, performing another craniotomy and clipping the residual UIAs. However, there is no consensus regarding this treatment method [119, 120, 126]. Alternatively, a combined surgical-endovascular approach can be performed, with surgery reserved for the ruptured and more difficult aneurysms [128, 129]. To summarize, deciding the management of multiple aneurysms should take into account the individual characteristics of the patient and of each the aneurysms, as well as the experience of the neurosurgical team involved.

At present, there are no corroborated management guidelines for UIAs in elderly

patients, yet the retrospective reports reveal excellent results for both treatment strategies [130–132]. It has been shown that elderly patients with UIAs are less likely to die following aneurysmal rupture SAH than younger and/or female patients [37, 40, 78, 133, 134]. Therefore, a conservative approach may also be considered especially for small UIAs. Even so, the advanced age in itself supposedly increases the risk of periprocedural complications. Surgical interventions are correlated with larger amounts of blood loss, higher treatment-related costs, and longer hospitalizations than endovascular techniques, though provide a complete and maintainable aneurysmal occlusion

*DOI: http://dx.doi.org/10.5772/intechopen.88038*

#### *Preventing Rupture: Clipping of Unruptured Intracranial Aneurysms DOI: http://dx.doi.org/10.5772/intechopen.88038*

*New Insight into Cerebrovascular Diseases - An Updated Comprehensive Review*

ogy be contended judiciously.

**8. Clipping of multiple aneurysms**

intervention.

In aspects to randomized studies comparing endovascular therapy to surgery, the literature is extremely limited. The Collaborative Unruptured Endovascular Versus surgery (CURES) trial, which randomized 104 patients harboring unruptured between 3 and 25 millimeters to either coiling (*n* = 56) or clipping (*n* = 48), showed that there were no significant differences regarding in aneurysm occlusion rate, mortality, and morbidity after 1 year [80, 109]. Nevertheless, there were more patients with perioperative neurological deficit after clipping and with hospitalizations beyond 5 days. Mortality and morbidity rates for CURES were lower than reported in the ISUIA regarding both clipping and coiling [109]. Another prospective study, the trial on endovascular management of unruptured intracranial aneurysms (TEAM), which compared coiling to observational management, was halted less than 3 years after initiation as a result of poor recruitment [110].

Another controversial subject is the management of aneurysm remnant or repermeabilization after clipping or coiling. It has been repeatedly demonstrated that microsurgery leads to fewer such instances [75–82]. Although the issue of hemorrhage after initial treatment and its consequences have been extensively covered for ruptured aneurysms, there is currently no such data for UIAs [39]. Patients should therefore be regularly monitored (we recommend yearly CTA investigations), regardless of the form of treatment and any increase in size or change in morphol-

Currently, the ideal strategy for solitary unruptured aneurysms is elusive. Although of great consequence, an issue seldom considered in these studies is the experience and proficiency of the neurosurgeon [73]. This is expressly observed in high-volume centers with a large number of operated cases, where outcomes are unquestionably much more favorable. Regardless, surgical prophylaxis of rupture via clipping remains a safe, effective, and possibly curative option. It remains to be seen whether the trends will continue to favor endovascular procedures or if an unexpected shift in balance might rejuvenate the popularity of surgical

In the Western population, it is estimated that 10–13% of patients with IAs possess MIAs, and it is sometimes difficult to find the source of SAH, but even more so to treat each lesion [70, 111–114]. A number of cases have been correlated with either congenital or chronic disorders such as Gaucher's disease, Fahr's disease, or Behcet's disease, although whether there is an etiologic correlation or merely a diagnostic coincidence is unknown [115–118]. Mirror aneurysms denote a rare condition in which the multiple aneurysms are placed symmetrically in the cerebral hemispheres. The most common sites are the non-cavernous segments of the ICAs [119, 120]. Mirror aneurysms also display a decreased propensity to rupture and improved outcomes than non-mirror aneurysms. Certain risk factors such as female gender (which also strongly influences the number of IAs), advanced age, smoking, uncontrolled hypertension, and increased body mass have been linked to a heightened chance of developing MIA [121, 122]. However, due to contradictory and inconclusive results, it is currently unknown whether the presence of MIAs implies a greater risk of rupture than that of single IAs [122]. Aneurysm morphology and size are thought to play the most important roles in the risk of rupture [91, 70]. Apparently, endovascular procedures lead to fewer neurologic complications than surgical clipping; however clipping yields higher occlusion rates, fewer total complications, and angiographic recurrence [69]. In theory, hemodynamic alterations occurring in an untreated distal UIA after the treatment of a proximal IA might

**160**

increase the risk of bleeding, underlying the necessity of treating all aneurysms simultaneously and by any means [66]. It is sometimes feasible to treat all aneurysms at the same time during the same sitting and using the same craniotomy, thus lowering hospital stay, surgical exposure, and risk of complications [119, 123–125].

We support the classical pterional approach for tackling multiple aneurysms of the anterior circulation in the same opening. It offers a wide enough opening to approach even the aneurysms of the M1 segment on the opposite side. This is mostly useful for selected patients with simple contralateral UIA with narrow necks and which project inferiorly or anteriorly [119, 123]. The craniotomy should be performed on the side of the most complex aneurysm, or the one which has ruptured. On one hand, this methodology provides the highest visibility of the aneurysm and shortest distance to the dome and hematoma in case of bleeding. On the other hand, because of the hemodynamic changes that might occur during the clipping of the other IAs, it is easier to control bleeding on this side.

Clipping the contralateral aneurysms first may prevent a complicated and hard to manage bleeding on this side. After that, clipping the aneurysms more proximal to the surgeon can be performed. There are, however, some drawbacks to this technique [123, 126]. Firstly, it implies a heightened brain retraction compared to that of the same-side craniotomy, yet this can be managed by adequate brain relaxation. The maneuverability is lower, and the vision is reduced on the opposite side. However, a larger craniotomy, wider arachnoid dissection, and brain relaxation can aid in this situation. Contralateral MCA bifurcation and PCoA aneurysms are more difficult to find and clip, requiring maneuvering around thin perforators and fragile veins. Hemostasis is not as easy on the distal side in the case of rupture, which is why these IAs should be clipped first. Lastly, this technique requires an experienced vascular neurosurgical team; however, surgical simulation with 3D reconstructions may alleviate results [127]. However, this surgery should only be performed in selected cases, as the risks associated with a single challenging surgery do not compensate for the expenses of two easier interventions (**Figure 4**).

From our operative experience, we contraindicate performing two surgeries on two separate days, as the risk of rupture of the remaining untreated UIAs during this interval is not negligible. If a single opening is not indicated, we recommend approaching the more complex aneurysms first through one craniotomy, and afterward, during the same anesthesia, performing another craniotomy and clipping the residual UIAs. However, there is no consensus regarding this treatment method [119, 120, 126]. Alternatively, a combined surgical-endovascular approach can be performed, with surgery reserved for the ruptured and more difficult aneurysms [128, 129]. To summarize, deciding the management of multiple aneurysms should take into account the individual characteristics of the patient and of each the aneurysms, as well as the experience of the neurosurgical team involved.
