Microsurgical Management of Intracranial Aneurysms in Côte d’Ivoire: A Series of 128 Cases

Introduction: The management of intracranial aneurysms in sub-Saharan Africa is essentially surgical. In this retrospective study, the authors report their experience in surgical management of intracranial aneurysm in Côte d’Ivoire. Methods: We carried out a retrospective study on patients operated for a ruptured or unruptured intracranial aneurysm between January 1st, 2012 and December 31st, 2018. Data on epidemiological characteristics of patients and aneurysms, treatments and patient outcomes were analyzed. Results: One hundred twenty eight aneurysms were operated. Sixty-six percent of the patients were female. According to the World Federation of Neurosurgical Societies (WFNS) scale, 58, 5% of patients were in grade I. Fisher scale showed 29% of Fisher 2 and 49% of Fisher 4. The aneurysms were mainly located on the internal carotid artery in 38% and anterior complex in 36%. The average size of aneurysms was 6.5 mm. In 81.4% the size of the aneurysms was less than 10 mm. Most aneurysms (90%) were treated at late stage. According to the modified Rankin Scale, 92 patients (83%) had good outcome, 7 patients (6%) had poor outcome, and the mortality rate was 11%. Conclusions: This study shows encouraging results if we refer to the overall postoperative results. However, there is a sub-diagnosis and low treatment rate of ruptured intracranial aneurysms. The improvement of intracranial aneurysms management requires improving the standard of health in the country.


Introduction
Microsurgery which has been for a long time the only treatment of intracranial aneurysms has been supplanted by endovascular treatment since the results of the International Subarachnoid Aneurysm Trial (ISAT) [1]. Currently endovascular treatment has become by far the first-line treatment of the great majority of ruptured and unruptured intracranial aneurysms. Some authors mention the end of surgical treatment of intracranial aneurysms [2].
In most sub-Saharan African countries, microsurgery remains the main treatment of intracranial aneurysms because of the unavailability of endovascular treatment. In most time, this microsurgery involves clipping or wrapping.
Rarely other techniques including trapping or proximal artery occlusion by surgical ligation are performed. The timing of microsurgery after aneurismal subarachnoid haemorrhage is controversial.
In Côte d'Ivoire, a developing country in West Africa, surgery remained the only treatment of intracranial aneurysms until 2018, when endovascular treatment became part of the therapeutic arsenal in treatment of intracranial aneurysms in the country.
In this paper, authors reported the epidemiological characteristics of their patients, the characteristics of aneurysms and the result of their management.

Patients and Methods
We carried out a retrospective study on patients operated for one or more rup-

Results
According to the protocol, 111 patients with 128 operated aneurysms were selected.

Age and sex
Men accounted for 34% of patients versus 66% for women. The age of the patients ranged between 13 and 78 years old with a mean age and a median age of 46 years ( Figure 1).

Aneurysms characteristics
A total of 128 aneurysms were diagnosed including 107 ruptured aneurysms and 21 unruptured aneurysms. These aneurysms were multiple in 15 patients (13.5%). Aneurysms were present in the anterior cerebral circulation in 98.5% and in the posterior cerebral circulation in 1.5% (Table 1).   CT angiography after microsurgery was performed in 61 patients with clipped aneurysms and revealed complete exclusion in all cases.
No case of rebleeding occurred after at least 1 year follow-up.

Discussion
Although there are very few publications about intracranial aneurysms in Africa, particularly in sub-Saharan countries, intracranial aneurysms are not uncom-   [13]. According to Okamoto et al. [13] the occurrence of menopause at a relatively low age and/or nulliparity are associated with an increased risk of subarachnoid haemorrhage, including aneurysmal rupture, in contrast a high number of pregnancies and multiparity would be protective factors. This phenomenon is explained by the high level of progesterone during pregnancy, which causes progesterone-oestrogen ratio in favour of progesterone. Early menopause and nulliparity are associated with elevated estradiol levels. Oestrogen promotes elevated blood pressure and decreased vascular resistance. It is clear therefore that progesterone is a protective element against the risk of vascular injury. It is thus understood that the drop in her rate after menopause exposes the woman to vascular lesions in general and particularly to subarachnoid haemorrhages by aneurismal rupture. This explains the female predominance of subarachnoid haemorrhage by aneurysmal rupture after the age of menopause.
Aneurysm Characteristics

Aneurysm locations
The international subarachnoid aneurysm trial (ISAT) found that 95% of aneurysms were located in the anterior cerebral circulation [1]. In our series 98.5% of the operated aneurysms were located in the anterior cerebral circulation. This could be explained by the fact that the aneurysms of the posterior cerebral circulation, which are easily amenable to endovascular treatment, have been rejected by surgery. The distribution of ruptured aneurysms according to their location varies according to the studies. In our series, the ruptured aneurysms that we operated were as much found in the anterior communicating artery as in the internal carotid artery. The predominant seat of ruptured aneurysms varies according to studies. However, most studies like ISAT [1] and Thioub study [3] report a predilection at the anterior communicating artery.

Form of aneurysms
We observed a high prevalence of sacciform aneurysms 96% against only 4% for fusiform aneurysms. Thioub et al. reported 92.3% of sacciform aneurysms and 7.7% fusiform aneurysm in their series [3].

Size of aneurysms
Many studies have attempted to determine a critical size at which an aneurysm is likely to rupture and thus justify its treatment.
In our series, the average size of aneurysms was 6.5 mm. The sizes of the aneurysms were less than 10 mm in 81.4%. Thioub et al. observed that 73% of operated aneurysms were smaller than 10 mm [3].

Preoperative condition
The major clinical manifestation of intracranial aneurysms is subarachnoid haemorrhage, which is the first manifestation in more than 90% of cases [14]. This aneurysmal rupture with onset of intracranial haemorrhage was the most common finding (96.5%) in our series.

Timing of surgery and overall surgical result
Despite the progress made in the surgery of intracranial aneurysms, there is no consensus about the optimal time for performing this surgery in order to obtain the best results in ruptured aneurysm. The work of Nieuwakamp, D.J. et al. [15] and Zhao, C. et al. [16] failed to prove the influence of surgical timing on patient outcomes. Yao, Z. et al. [17] in their study observed that early surgery was superior to late surgery in reducing a poor outcome and death rate when patients were in good condition on admission, and decreased the incidence of poor outcome when patients were in poor condition on admission.
The majority of our patients were operated at the late stage for several reasons: • delayed diagnosis especially for late consultation, • financial difficulty because there is no national social security and care is in most cases the responsibility of the patient, • the current protocol in our service recommends to operate the patient either within 3 days following the rupture or beyond the 15th day.
We recommend early surgery to prevent early rebleeding especially since it does not seem harmful to the patient.

Aneurysm surgery
Most authors, like Lafuente [6] and Thioub [3], report that clipping is by far the most commonly surgical technique used in intracranial aneurysm surgery.
This technique was used in 92% of the aneurysms we treated.

Conclusions
This study shows encouraging results if we refer to the overall postoperative results. However, there is a sub-diagnosis and a low treatment rate of ruptured intracranial aneurysms because of the weakness of the country's health system.
The improvement of intracranial aneurysms management requires the establishment of national social coverage and improvement of the technical platform of the health structures in the country.

Conflicts of Interest
The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.