Key-words:
Aneurysm clipping - aneurysm trapping - aneurysmal subarachnoid hemorrhage - ruptured
intracranial aneurysm
Introduction
Clinical outcomes of ruptured intracranial aneurysms vary widely and depend on several
factors.[[1]],[[2]],[[3]],[[4]] Long-term outcome is affected by the severity of initial presentation, amount of
blood on computed tomography (CT) at presentation, initial resuscitation, and patient
management. At our hospital, aneurysmal subarachnoid hemorrhage (aSAH) is treated
with surgical obliteration of the aneurysm by direct clipping, trapping with or without
bypass, or aneurysmal wrapping or coating. This retrospective study aimed to analyze
factors affecting 1-year outcome in aSAH patients who underwent surgical aneurysm
treatment.
Materials and Methods
Patient selection
Two hundred sixty-five patients diagnosed with spontaneous SAH and intracranial aneurysm
who were treated at Vajira Hospital between January 2013 and May 2016 were eligible
for study inclusion. We included only those with ruptured intracranial aneurysms that
were surgically treated. Forty-four patients were excluded because of unruptured or
undetectable intracranial aneurysm or treatment with a modality other than surgical
obliteration. Ruptured aneurysm patients were surgically treated within 24 h after
arrival at our hospital (referral or newly visited). In the patients who needed emergency
ventriculostomy, the procedure was performed before craniotomy in the same operation.
In case that craniotomy could not perform in the same operation due to requirement
of further investigations or under resuscitations, ventriculostomy was performed first.
For unstable or poor-grade patients who were not eligible for surgery or caregiver
refused aggressive treatments, conservative treatments were done.
Direct clipping of aneurysm with preservation of parent artery was attempted in all
cases. If failed, other modalities including proximal parent arterial occlusion, trapping
with bypass, wrapping, or coating were done.” change to “Clipping of aneurysms were
attempted in all cases. If the aneurysm cannot be clipped, other modalities (proximal
parent arterial occlusion, trapping of aneurysm with bypass, wrapping of aneurysm
or coating of aneurysm) were done. Parent arteries and surrounded perforators were
evaluated patency by using intraoperative Doppler ultrasound and indocyanine green
video-angiography. Postoperation, patients were treated within the neurosurgical intensive
care unit. If delayed ischemic neurological deterioration (DIND) is suspected in case
of newly developed of focal neurological deficit, there is a decreased level of consciousness
or new-onset seizure. The imaging and laboratory investigations were done to exclude
possible causes of DIND. Specific treatments were given to patients with the obvious
cause of DIND. If the investigations did not show explainable causes, patients were
treated as clinical vasospasm, blood pressure was elevated by using intravenous inotropic
drugs until symptoms improved or maximal systolic blood pressure (220 mmHg) was reached.”
change to “If there were not obvious causes of deterioration, the patient was treated
as clinical vasospasm. Blood pressure was elevated by intravenous inotropic drugs
until symptoms improved or maximal systolic blood pressure (220 mmHg) was reached.
Finally, 221 patients were included. Clinical data regarding patient and aneurysm
characteristics, clinical status at presentation, treatment, and status at discharge
and 1 year after discharge were recorded.
Outcome assessment
Outcomes 1 year after surgery were assessed using the Glasgow Outcome Scale (GOS).[[5]],[[6]] Patients were divided into two groups according to the GOS score: the favorable
outcome group (GOS scores 4 and 5) and unfavorable outcome group (GOS scores 1–3).
Patient and clinical characteristics were analyzed to assess association with functional
outcome.
Statistical analysis
Statistical analyses were conducted using GNU PSPP version 1.2.0 software. Data between
groups were compared using the unpaired t-test, Fisher's exact test, and Chi-square
test as appropriate. P < 0.05 was considered significant.
Results
Patient and clinical characteristics are shown in [[Table 1]]. Among the 158 patients (71.4%) of the favorable outcome group, 57 were male (36.1%)
and 101 were female (63.9%). In this group, the mean age was 49.8 years and the mean
Hunt and Hess grade was 2.4. Seventy-five patients (47.7%) were Hunt and Hess Grade
2. Aneurysm distribution [[Table 2]] was as follows: ophthalmic artery aneurysm: 4 (2.5%); superior hypophyseal artery
aneurysm: 1 (0.6%); posterior communicating artery (PcoA) aneurysm: 32 (20.2%); anterior
choroidal artery aneurysm: 5 (3.1%); internal carotid artery bifurcation aneurysm:
4 (2.5%); anterior communicating artery (AcoA) aneurysm: 60 (37.9%); anterior cerebral
artery (ACA) aneurysm: 10 (6.3%); middle cerebral artery (MCA) aneurysm: 27 (17.2%);
posterior–inferior cerebellar artery (PICA) aneurysm, 6 (3.8%); vertebral artery aneurysm
(including aneurysm at the vertebrobasilar junction): 4 (2.5%); superior cerebellar
artery aneurysm: 2 (1.2%); and basilar tip aneurysm: 3 (1.9%). The superficial temporal
artery–MCA bypass with proximal occlusion of MCA was performed in one patient presenting
with unclippable MCA aneurysm.
Table 1: Patient and clinical characteristics and outcome groups
Table 2: Aneurysm characteristics and outcome groups
Among the 63 patients (28.5%) of the unfavorable outcome group, 19 were male (30.1%)
and 44 were female (69.9%). The mean age was 59.7 years and the mean Hunt and Hess
grade was 3.2. An equal number of patients (19) were Hunt and Hess Grades 3 and 4.
Aneurysm distribution was as follows: ophthalmic artery aneurysm: 2 (3.1%); superior
hypophyseal artery aneurysm: 1 (1.5%); PcoA aneurysm: 20 (31.7%); anterior choroidal
artery aneurysm: 1 (1.5%); internal carotid artery bifurcation aneurysm: 2 (3.1%);
AcoA aneurysm: 14 (22.2%); ACA aneurysm: 3 (4.7%); MCA aneurysm: 8 (12.6%); PICA aneurysm:
2 (3.1%); vertebral artery aneurysm (including aneurysm at the vertebrobasilar junction):
4 (6.3%); superior cerebellar artery aneurysm: 2 (3.1%); and basilar tip aneurysm:
4 (6.3%). In case of vertebral artery dissection (one patient) involvement of origin
of PICA, the occipital artery–PICA bypass with proximal occlusion of the vertebral
artery was performed.
Age at presentation and Hunt and Hess grade were significantly higher in the unfavorable
outcome group than the favorable outcome group (P < 0.05). The mean aneurysm size
was significantly smaller in the favorable outcome group (6.3 mm vs. 7.5 mm; P = 0.049).
The proportion of patients who developed clinical vasospasm did not significantly
differ between the favorable and unfavorable outcome groups (10.1% vs. 14.3%; P =
0.48). The mean GOS score at discharge was significantly higher in the favorable outcome
group (4.2 vs. 2.4; P < 0.05). Seventy-three patients (46.2%) in the favorable outcome
group had good recovery status (GOS score 5) at discharge.
Aneurysm locations and characteristics of unfavorable outcome group
As shown in [[Table 3]], aneurysmal characteristics and intraoperative results of unfavorable outcome group
based on aneurysm locations were shown as follows: mean age, mean aneurysm size, mean
date of operation (SAH date), number of patients with intraoperative rupture of aneurysm,
mean intraoperative blood loss, and postoperative complications. The mean age in each
aneurysm location was as follows: internal carotid artery aneurysm: 59 years; PcoA
aneurysm: 67 years; AcoA aneurysm: 52 years; ACA aneurysm: 60 years; MCA aneurysm:
60 years; and posterior circulation: 57 years. Aneurysm size in mean was as follows:
internal carotid artery aneurysm: 7.5 mm; PcoA aneurysm: 8.7 mm; AcoA aneurysm: 6
mm; ACA aneurysm: 9 mm; MCA aneurysm: 5.8 mm; and posterior circulation: 8.0 mm. The
mean operative date after SAH was highest in ACA aneurysm as date 13, equally in ICA
aneurysm and AcoA aneurysm as date 6, and date 6.7, 4.5, and 3 in posterior circulation
aneurysm, PcoA aneurysm, and MCA aneurysm, respectively. The results of intraoperative
rupture of aneurysm during surgery were highest in AcoA aneurysm, followed by PcoA
aneurysm, posterior circulation aneurysm, MCA aneurysm, and ICA aneurysm. None occurred
in ACA aneurysm. Furthermore, [[Table 3]] also shows the mean intraoperative blood loss and postoperative complications in
each aneurysm location.
Table 3: Aneurysm characteristics of unfavorable outcome group
Relationship of shunt dependency to 1-year functional outcome
The proportion of patients who underwent shunt placement was significantly higher
in the unfavorable outcome group than the favorable outcome group (36.5% vs. 17.1%;
P = 0.0039).
Discussion
In this study of 221 patients who underwent surgical treatment of ruptured intracranial
aneurysms, multiple factors were associated with 1-year outcome. Previous studies
and meta-analyses have shown that neurological status is the strongest predictor of
outcome after aSAH; other predictors include age, aneurysm repair modality, Fisher
grade, hypertension, and aneurysm size and location.[[7]],[[8]],[[9]],[[10]] Cognitive decline and memory deficit persist in patients with aSAH, even in those
with good functional outcomes.[[11]],[[12]],[[13]],[[14]] Clinical vasospasm is more frequent in poor-grade SAH patients; however, some studies
could not demonstrate a significant relationship with outcome up to the individualized
collateral flow of patients.[[15]],[[16]]
Our analysis of patient and clinical characteristics according to the outcome group
showed significant group differences in age, neurological status (Hunt and Hess grade),
and aneurysm size. Patients in the favorable outcome group were younger, had smaller
aneurysms, and lower Hunt and Hess grade. Patients in the favorable outcome group
were predominantly Grades 2 and 3, whereas those in the unfavorable outcome group
were predominantly Grades 3 and 4.
Aneurysm location also differed between the groups. The AcoA was the most common location
in the favorable outcome group, whereas the PcoA was the most common in the unfavorable
outcome group. Moreover, the proportion of patients with posterior circulation aneurysms,
which may be associated with worse long-term outcome, was higher in the latter.
Furthermore, the unfavorable outcome group was analyzed, as shown in [[Table 3]]. The PcoA aneurysms were highest in this group, also carry the highest patients'
mean age. The mean aneurysm size was highest in ACA aneurysm, followed by PcoA aneurysm,
but the difference in each group showed no statistically significant. Other factors
(operation date after symptomatic SAH, number of aneurysms with intraoperative rupture,
intraoperative blood loss, and postoperative complications) were also analyzed but
did not show any statistically significant difference.
The proportion of patients who developed clinical vasospasm and shunt dependency was
lower in the favorable outcome group. Previous studies have found that poor neurological
status is associated with a higher amount of blood on CT at presentation and development
of chronic hydrocephalus. In our institution, one of the neurosurgeons uses irrigation
of Vitamin C solution (1000 mg in 0.5 L of normal saline) into the subarachnoid space
intraoperatively; the proportion of patients who received Vitamin C irrigation was
significantly higher in the favorable outcome group. The literature has shown mixed
results of usage of Vitamin C in aSAH patients. In vitro studies found ascorbic acid
(Vitamin C) suppressed the ability of Oxy-Hb to constrict cerebral arteries by conversion
of oxyhemoglobin (Oxy-Hb) to verdoheme-like products.[[17]] However, some study shown significant reduction of clinical vasospasm in high grade
subarachnoid hemorrhage (Fisher grading 3 and more) by using continuous irrigation
of urokinase and ascorbic acid into subarachnoid space.[[18]],[[19]] Our study used intraoperative irrigation of Vitamin C into subarachnoid space without
thrombolytic agents. A better study design should be further evaluated the significance
of Vitamin C irrigation to the outcome of aSAH patients.
Limitations
Several limitations of this study should be noted. First, the study was retrospective
in design. Second, we did not evaluate cognitive and memory function, only GOS score.
Although ruptured AcoA aneurysms are associated with worse functional outcome, particularly
decreased cognitive and memory function, we found that these aneurysms were more common
in the favorable outcome group. Third, we did not record data regarding vasospasm
treatment and treatment outcome, which is associated with overall outcome and morbidity.
However, the proportion of patients who developed clinical vasospasm did not significantly
differ between the favorable and unfavorable outcome groups. Finally, subarachnoid
space irrigation with Vitamin C solution was only performed by a single surgeon. Further
study of Vitamin C irrigation is warranted.
Conclusions
Numerous factors analyzed in this study were significantly associated with 1-year
outcome in surgically treated aSAH patients. Most are similar to those found in previous
studies. Subarachnoid space irrigation with Vitamin C solution was significantly associated
with favorable outcomes. However, due to the design limitations of this study, future
prospective studies including various treatment interventions are required.
