Real-World Outcomes of Endovascular Management of Intracranial Aneurysms: Insights from a Tertiary Care Hospital in Central India

Keywords

coiling - aneurysm - endovascular

Introduction

Endovascular coiling has emerged as the preferred treatment for intracranial aneurysms (IAs) in many countries, particularly following the landmark findings of the International Subarachnoid Aneurysm Trial (ISAT).[1] This pivotal study demonstrated that endovascular coiling, compared with surgical clipping, reduced the absolute risk of death or dependency by 7.4% at 1 year. Furthermore, coiling was associated with significantly better functional outcomes, with fewer patients experiencing mortality or dependency. These findings firmly established coiling as the standard treatment for ruptured aneurysms in many clinical settings, driving the widespread adoption of endovascular techniques for aneurysm management.

Since the Food and Drug Administration approval of Guglielmi detachable coils in 1995, endovascular treatment for IAs has advanced rapidly.[2] Innovations in catheter and guidewire technology, coupled with the refinement of digital angiography, have significantly improved the precision and safety of these procedures. Once considered an alternative or adjunct to surgical intervention for treating complex or inaccessible lesions, endovascular coiling is now the frontline treatment for a broad range of aneurysms. It is particularly advantageous for patients with medical comorbidities, poor clinical grades, or aneurysms with favorable characteristics, such as narrow necks, high fundus-to-neck ratios, posterior circulation locations, and multiple aneurysms.[3]

Establishing neurointervention services in a Tier-2 city within a publicly funded hospital posed several challenges. These included a shortage of trained technicians to operate the biplane Digital Subtraction Angiography (DSA) laboratory, limited availability of nursing staff experienced in stroke care and cath laboratory procedures, and significant difficulties in setting up a reliable supply chain for neurointervention hardware. These challenges have been discussed in detail in our previous publication on developing neurointervention services at our center based on our initial experience.[4]

There is often a significant delay in patient referrals from peripheral centers, primarily due to a lack of awareness about appropriate treatment options. This has led to delays in timely management. However, with sustained efforts and targeted awareness campaigns, we have begun receiving referrals more promptly.

In this study, we present our experience with the endovascular management of IAs at a publicly funded hospital in Central India. Our primary objectives were to provide a detailed analysis of the demographic and clinical profiles of patients with IAs in our cohort, including aneurysm subtypes, locations, and sizes. Additionally, we aimed to evaluate the success rates of various endovascular treatment modalities and document complications encountered in routine clinical practice. By conducting this real-world analysis, we aim to contribute valuable insights into the effectiveness and challenges of endovascular treatment for managing IAs, particularly in resource-constrained settings.

Materials and Methods

This retrospective study included patients who underwent endovascular treatment for IAs at the Neuroradiology Department of our institute between March 2021 and December 2023. Demographic, clinical, and imaging data were collected and analyzed retrospectively. The study protocol was reviewed and approved by the local ethics committee.

Data related to aneurysms, including size, shape, neck size, aspect ratio, rupture status, and location, were meticulously documented. For ruptured aneurysms, the severity of subarachnoid hemorrhage (SAH) was assessed using the modified Fisher grade, while the World Federation of Neurosurgical Societies (WFNS) grading scale was used to evaluate clinical status at presentation. Any incidents of re-rupture following the initial rupture were recorded, along with the presence or absence of co-existing aneurysms.

Endovascular procedures were performed under general anesthesia. Following catheterization of the vertebral or internal carotid artery, a contrast agent was injected to establish a navigational roadmap. Using a coiling microcatheter and appropriate guidewires, the aneurysm was cannulated. The treatment approach—whether simple coiling, balloon-assisted coiling, stent-assisted coiling, flow diverter placement, or braided stent monotherapy—was selected based on the aneurysm's size, morphology, and location. The number of coils and/or stents deployed was tailored to the specific characteristics of each aneurysm.

Patient outcomes at discharge were classified using the modified Rankin Scale (mRS) as follows: good outcome (mRS 0–2), poor outcome (mRS 3–5), or death. Procedure-related complications were thoroughly recorded. For ruptured aneurysms, particular attention was given to the occurrence of vasospasm and hydrocephalus during the hospital stay.

Follow-up angiographic outcomes were evaluated using the Modified Raymond–Roy Classification (MRRC) grading scale to assess the degree of aneurysm occlusion. Long-term functional outcomes were measured by mRS scores during follow-up. Linear regression analysis was conducted to identify factors associated with clinical outcomes.

Results

A total of 103 IAs were treated in 100 patients, aged 2 to 75 years. The cohort comprised 59 females and 41 males. [Table 1] shows distributions across age groups for females and males. Clinical presentation and known co-morbidities are summarized in [Table 2].

Table 1 Distributions across age groups for females and males

Age group	Female	Male
0–20 years	1	1
20–40 years	4	8
40–60 years	35	26
60–80 years	19	6
>80 years	0	0
Total	59	41

Table 2 Clinical presentation and known comorbidities of patients

Presentation ruptured/unruptured	Symptoms	Frequency
Ruptured	Headache	92
	Vomiting	32
	Loss of consciousness at time of ictus	32
	Epistaxis	1
	Altered sensorium	26
	Hemiparesis	11
	Monoparesis	1
	Aphasia	3
	Seizures	3
Unruptured	Headache	3
	Diplopia (giant cavernous ICA aneurysm)	1
	Vision loss (giant supraclinoid ICA aneurysm compressing chiasma)	1
	Ptosis (posterior communicating artery aneurysm)	1
	Vertigo, quadriparesis (mass effect due to giant V4 segment aneurysm with brainstem compression)	1
	Seizures (associated insular AVM)	1
	Incidental detection with another ruptured aneurysm (patient included in ruptured presentation also)	1
Known comorbidities	Hypertension	35
	Diabetes mellitus type 2	5
	Chronic obstructive pulmonary disease (COPD)	1
	Hypothyroidism	1
	Coronary artery disease	1
	Retropositive status	1

Abbreviations: AVM, arteriovenous malformation; ICA, internal carotid artery.

Aneurysms were categorized by size as follows: tiny (<3 mm): 11; small (3–7 mm): 67; medium (7–10 mm): 19; large (10–25 mm): 5; giant (>25 mm): 1.

Of the 103 aneurysms, 86 were located in the anterior circulation and 17 in the posterior circulation. The anterior communicating artery was the most common site (n = 42/103; 42.7%). Aneurysm morphology included 94 saccular aneurysms, 7 dissecting aneurysms, 1 blister aneurysm, and 1 fusiform aneurysm. Among saccular aneurysms, 73 had a narrow neck, while 21 had a wide neck. Aneurysm size and locations are summarized in [Table 3].

Table 3 Size and location of aneurysms

Size of aneurysms	Number
Tiny (<3 mm)	11
Small (3–7 mm)	67
Medium (7–10 mm)	19
Large (10–25 mm)	5
Giant (>25 mm)	1
Total aneurysms	103
Location of aneurysm	Number
Anterior circulation
Anterior communicating artery	44
Middle cerebral artery bifurcation	3
M1 segment	3
Distal anterior cerebral artery	10
A1 segment of anterior cerebral artery	4
Posterior communicating artery	8
Supraclinoid internal carotid artery	5
Superior hypophyseal	1
Cavernous paraclinoid segment	4
Terminal ICA	2
Choroidal segment	1
Supraclinoid ICA pseudoaneurysm	1
Total anterior circulation	86
Posterior circulation
Posterior inferior cerebellar artery	3
Vertebral artery V4 segment	7
P1 segment of posterior cerebral artery	1
Basilar top	5
Superior cerebellar artery	1
Total posterior circulation	17
Total aneurysms	103

Abbreviation: ICA, internal carotid artery.

Ninety-two patients presented with SAH. In some cases, the exact rupture site could not be determined due to the presence of multiple aneurysms in the same vessel or on the ipsilateral side of dense SAH. There were two such patients (one with anterior communicating aneurysm and anterior choroidal aneurysm, and another patient with two aneurysms in A1 segment of anterior cerebral artery) and in both patients all these aneurysms were coiled at the same time. Vessel-wall magnetic resonance imaging could not be done as the vessel-wall imaging/black blood imaging sequence is not available in our hospital. A total of 94 ruptured aneurysms and 9 unruptured aneurysms were treated. The time from ictus to presentation ranged from 1 day to 1 month.

Among the 92 patients with ruptured aneurysms, WFNS grading and modified Fisher grade of SAH at presentation are summarized in [Table 4]. Poor neurological grade at presentation (WFNS grades 4 and 5) were observed in 27.1% of patients (n = 25/92). Furthermore, fifty patients (n = 50, 54.3%) had Modified Fisher grade 4 SAH, indicating severe hemorrhage.

Table 4 WFNS grade and Modified Fisher Grade at presentation for patients presenting with subarachnoid hemorrhage (n = 92)

Grade at presentation	Number
WFNS grade
WFNS grade 1	56
WFNS grade 2	6
WFNS grade 3	5
WFNS grade 4	21
WFNS grade 5	4
Modified Fisher grade
Modified Fisher grade 1	15
Modified Fisher grade 2	6
Modified Fisher grade 3	21
Modified Fisher grade 4	50

Abbreviation: WFNS, World Federation of Neurosurgical Societies.

Out of total 103 aneurysms in 100 patients, two aneurysms (unruptured) spontaneously closed, and 6 patients died before any intervention. Total 92 patients underwent endovascular procedure for 95 aneurysms and the following procedures were performed: simple coiling: 60 cases, balloon-assisted coiling: 18 cases, double micro-coiling: 4 cases, flow diverter placement: 7 cases, braided stent monotherapy: 4 cases, and balloon occlusion followed by vascular sacrifice: 2 cases. Examples of few procedures are given in [Fig. 1].

Fig. 1 (A–C) Simple coiling of left superior hypophyseal aneurysm. Left ICA injection AP view shows left superior hypophyseal aneurysm. Panel (B) shows coil mass; (C) shows post-coiling subtracted image showing complete occlusion. (D–F) Balloon-assisted coiling of left ICA communicating segment aneurysm. (D) Left ICA injection lateral view shows left ICA communicating segment aneurysm. Panel (E) shows coil mass with balloon inflation across neck of aneurysm; (F) shows post-coiling subtracted image showing occlusion with minimal filling near neck of aneurysm (MRRC grade IIIa). (G–I) Flow diverter stenting for left MCA M1 segment aneurysm. (G) Left ICA injection AP view shows left MCA M1 segment aneurysm. Panel (H) shows flow diverter stent in situ. (I) Follow-up image 10 months following intervention, Intravenous DynaCT image showing complete occlusion of aneurysm with patent flow diverter stent in situ. AP, antero-posterior; ICA, internal carotid artery; MCA, middle cerebral artery; MRRC, Modified Raymond–Roy Classification.

There were six deaths due to preintervention re-rupture of aneurysm. Seven patients experienced aneurysm re-rupture before endovascular treatment, with intervals of 6 to 20 days after ictus. Of these, six patients died, and one survived with an mRS score of 1.

For coiled aneurysms, postprocedure occlusion rates were: complete occlusion (RR1): 73.2% (n = 60), near-complete occlusion (RR2): 24.4% (n = 20), partial occlusion (RR3): 2.4% (n = 2).

Procedural complications included thromboembolic events: 6 cases, intraoperative aneurysm rupture: 2 cases, and coil migration requiring craniotomy: 1 case. Hydrocephalus developed in 15 patients, and angiographic vasospasm occurred in 48 patients. Vasospasm-related infarcts were observed in four patients, and transient neurological deficits in two.

At discharge following endovascular intervention (n = 92), 81.5% (n = 75) achieved favorable outcomes (mRS 0–2), indicating functional independence. Poor outcomes (mRS 3–5) were noted in 10 patients (10.8%), while 7 patients (7.6%) died. Two patients with spontaneous aneurysm closure remained stable. Types of endovascular procedures, outcome at discharge, and complications encountered are summarized in [Table 5].

Table 5 Types of endovascular procedures, outcome at discharge, and complications encountered

Grade at presentation	Number
Type of procedure
Simple coiling	60
Balloon-assisted coiling	18
Double microcatheter coiling	4
Flow diverter	7
Braided stent monotherapy	4
Balloon occlusion test followed by vascular sacrifice	2
Spontaneous closure	2
Conservative (death before any procedure could be performed)	6
Total aneurysms	103
Outcomes at discharge for 92 patients who underwent endovascular procedure
Favorable outcome mRS 0–2	75
Poor outcome mRS 3–5	10
Death mRS 6	7
Complications following endovascular procedure
Thromboembolic events	6
Intraoperative rupture	2
Coil migration requiring craniotomy	1
Complications due to subarachnoid hemorrhage
Hydrocephalus	15
Angiographic vasospasm	48
Vasospasm-related infarcts	4
Vasospasm-related transient neurological deficits	2

Abbreviation: modified Rankin Scale.

Linear regression analysis identified the following significant correlations: poor outcomes associated with high WFNS grade SAH (p = 0.0007), presence of spasm (p = 0.0007), and thromboembolic events (p = 0.0011). Hydrocephalus correlated with poor WFNS grade (p = 0.0001) and posterior circulation aneurysms (p = 0.0381). Spasm was significantly linked to high Fisher grade SAH (p < 0.0001), poor WFNS grade SAH (p = 0.006), and wide-neck aneurysms (p = 0.0011). Linear regression analysis tables are summarized in [Tables 6] to [9].

Table 6 Linear regression analysis table for factors associated with poor patient outcomes

Variable	95% CI	p-Value	Significance
Neck size [wide]	−0.4224 to 0.06889	0.1558	Not significant
Aspect ratio	−0.1674 to 0.06322	0.3710	Not significant
WFNS grade [poor]	−0.5476 to −0.1520	0.0007	Significant[a]
Location [posterior]	−0.1463 to 0.3692	0.3915	Not significant
Fisher grade	−0.03584 to 0.1100	0.3142	Not significant
Size	−0.02989 to 0.2659	0.1161	Not significant
Spasm [yes]	−0.5096 to −0.1411	0.0007	Significant[a]
Hydrocephalus [yes]	−0.3903 to 0.05760	0.1431	Not significant
Thromboembolic event [yes]	−0.9253 to −0.2407	0.0011	Significant[a]

Abbreviations: CI, confidence interval; WFNS, World Federation of Neurosurgical Societies.

^a Statistically significant.

Table 7 Linear regression analysis table for factors associated with development of hydrocephalus

Variable	95% CI	p-Value	Significance
Neck size [wide]	−0.4680 to 0.01273	0.0631	Not significant
Aspect ratio	−0.1629 to 0.06855	0.4195	Not significant
Location [posterior]	0.01501 to 0.5186	0.0381	Significant[a]
WFNS grade [poor]	0.2538 to 0.6021	<0.0001	Significant[a]
Fisher grade	−0.02988 to 0.1162	0.2429	Not significant
Size	−0.05186 to 0.2409	0.2024	Not significant
Thromboembolic event [yes]	−0.1765 to 0.4853	0.3558	Not significant
Spasm [yes]	−0.3161 to 0.04651	0.1429	Not significant

Abbreviations: CI, confidence interval; WFNS, World Federation of Neurosurgical Societies.

^a Statistically significant.

Table 8 Linear regression analysis table for factors associated with development of vasospasm

Variable	95% CI	p-Value	Significance
Neck size [wide]	−0.7648 to −0.1986	0.0011	Significant[a]
Aspect ratio	−0.2457 to 0.03722	0.1463	Not significant
Location [posterior]	−0.2900 to 0.3491	0.8544	Not significant
WFNS grade [poor]	0.09817 to 0.5667	0.0060	Significant[a]
Fisher grade	0.1162 to 0.2750	<0.0001	Significant[a]
Size	−0.03754 to 0.3219	0.1193	Not significant
Hydrocephalus [yes]	−0.4815 to 0.07086	0.1429	Not significant
Thromboembolic event [yes]	−0.3379 to 0.4828	0.7261	Not significant

Abbreviations: CI, confidence interval; WFNS, World Federation of Neurosurgical Societies.

^a Statistically significant.

Table 9 Linear regression analysis table for factors associated with thromboembolic event

Variable	95% CI	p-Value	Significance
Neck size [narrow]	−0.2886 to 0.04201	0.1416	Not significant
Aspect ratio	−0.04377 to 0.1139	0.3784	Not significant
Location [posterior]	−0.2332 to 0.1191	0.5211	Not significant
WFNS grade [poor]	−0.2031 to 0.06713	0.3196	Not significant
Fisher grade	−0.04421 to 0.05628	0.8117	Not significant
Size	−0.09327 to 0.1085	0.8810	Not significant
Spasm [yes]	−0.1032 to 0.1474	0.7261	Not significant
Hydrocephalus [yes]	−0.08210 to 0.2257	0.3558	Not significant

Abbreviations: CI, confidence interval; WFNS, World Federation of Neurosurgical Societies.

At follow-up (3 months to 2 years) of 85 surviving patients: 91.7% (n = 78) had an mRS score of 0 to 2, one patient had mRS score of 4. Six patients died due to causes including liver failure and myocardial infarction; the remaining deaths had incomplete records. All four of these patients had poor mRS at discharge. At 2 years posttreatment, among 92 patients who underwent endovascular treatment of some form, 84.7% (n = 78) of patients were functionally independent, and 14.1% (n = 13) had died.

Angiographic data for coiled aneurysms were available for 43 patients, which showed: complete occlusion (RR1): 74.4% (n = 32), near-complete occlusion (MRRC grade 2): 4 patients, and partial occlusion (MRRC 3A/3B): 3 patients (2 required repeat interventions). Spontaneous resolution on follow-up angiography was noted in one patient. Among four patients with flow diverters, three achieved occlusion (O'Kelly–Marotta [OKM] grade D), and one had a patent aneurysm at follow-up (OKM grade A2).

Discussion

The ISAT established endovascular coiling as a superior alternative to surgical clipping for ruptured aneurysms amenable to both treatment modalities. ISAT reported that 23.5% of patients treated with endovascular coiling were dead or dependent at 1 year, compared with 30.9% in the surgical group, yielding an absolute risk reduction of 7.4%.[1] Similarly, the Brain Aneurysm Treatment (BRAT) study demonstrated better outcomes with coiling, with 23.2% of patients in the endovascular group experiencing poor outcomes (mRS > 2), compared with 33.7% in the surgical group.[5]

A meta-analysis further confirmed these findings, showing that although coiling carries a slightly higher risk of early rebleeding, it remains associated with better functional outcomes compared with surgical clipping.[6] At our institution, the advent of neurointerventional facilities has allowed endovascular coiling to become the first-line treatment for ruptured aneurysms. Surgical clipping is reserved for patients requiring hematoma evacuation, those with complex middle cerebral artery aneurysms, or wide-neck aneurysms where stent-assisted coiling may not be economically feasible for all patients. Decision for type of endovascular modality was based on aneurysm morphology with narrow neck aneurysm (<4 mm) and aspect ratio >1.6 treated by simple coiling, and wide neck aneurysms treated by balloon/double microcatheter-assisted coiling. Flow diverter was chosen for blister aneurysm, fusiform/dissecting and giant aneurysms, and braided stent was chosen for dissecting aneurysm.

Angiographic outcomes revealed that 62% of aneurysms in our cohort achieved complete occlusion, while 33% showed small neck remnants, which is similar to findings reported in ISAT (66% complete occlusion, 26% neck remnant).[1] These findings highlight the potential for recurrence and the need for vigilant follow-up and occasional retreatment. ISAT similarly reported a retreatment rate of 17.4% due to residual or recurrent aneurysms following coiling.[7]

Thromboembolic complications occurred in 6.5% of our patients, consistent with rates reported in the literature (4.7–12.5%).[8] [9] [10] [11] [12] [13] Factors contributing to thromboembolic events include large aneurysm size, wide necks, and smoking.[9] Intraoperative rupture, a known risk during coiling procedures, was observed in two cases in our cohort, falling within the reported range of 0.7 to 7.5%, depending on aneurysm complexity and location.[8] [9] [14] [15] [16] [17]

Cerebral vasospasm is a frequent and serious complication following SAH, affecting up to 50% of patients, with angiographic spasm rate as high as 70%.[18] [19] In our cohort, angiographic vasospasm was present in 52.1% of patients, aligning with the literature. Vasospasm can be asymptomatic, but in 20 to 30% of cases, it leads to significant neurological deficits, contributing to morbidity and mortality.[19] Risk factors include SAH severity, patient age, clinical grade, aneurysm size and location, and the presence of intraventricular hemorrhage.[19] In our study, spasm was significantly linked to high Fisher grade SAH (p < 0.0001), poor WFNS grade SAH (p = 0.006), and wide-neck aneurysms (p = 0.0011).

Although delayed rebleeding rates are higher with coiling than clipping, especially within the first year, long-term rebleeding risks remain low. At end of follow-up, the cumulative risk of a rebleed from the target aneurysm was 0.0216 (95% confidence interval: 0.0121–0.0383) for patients in the endovascular group and 0.0064 (0.0024–0.0173) for patients in the neurosurgery group.[20] Thus, according to the literature, despite the higher early rebleeding risk, coiling is associated with better long-term functional outcomes. We did not document any evidence of rebleed post-procedure during the duration of follow-up. However, four patients died on follow-up for whom cause of death is not known. All these patients had poor mRS at discharge.

In our study, 84.7% of patients who underwent endovascular treatment achieved functional independence (mRS 0–2) at discharge, aligning closely with outcomes reported in ISAT.[1] However, the mortality rate in our cohort was 14.1%, slightly higher than ISAT's 8% at 1 year. This difference may be explained by the higher proportion of poor-grade SAH cases in our cohort (27.1%, compared with 12% in ISAT).[1]

Our findings are comparable to those from the BRAT study, which reported 87.2% of patients in the endovascular group achieving independence at 1 year.[5] Encouragingly, 91.7% of surviving patients in our cohort maintained functional independence at follow-up (3 months to 2 years), suggesting that long-term outcomes remain consistent with larger, multicenter trials.

In addition to larger studies, our findings are also comparable to other single-center experiences. For instance, Klompenhouwer et al reported outcomes from endovascular management of 230 patients, with good outcomes (mRS 0–2) observed in 87.2% of surviving patients.[21] Similarly, Gudelj et al documented favorable outcomes (mRS 0–1) in 79% of 33 treated patients.[22] Elewa reported outcomes in 31 patients who underwent endovascular treatment, with favorable outcomes (mRS 0–2) at discharge observed in 74.3% of cases, while 25.7% had unfavorable outcomes (mRS 3–6).[23]

Our study has several limitations. Follow-up irregularities remain a challenge, with angiographic follow-up data available for only 43 patients. Additionally, the dataset is heterogeneous in terms of aneurysm location, size, morphology, rupture status, and the type of endovascular treatment administered. Nonetheless, this analysis was conducted using the entirety of the dataset currently available to us. Future studies with larger, more homogeneous cohorts are warranted to enable more statistically robust conclusions.

Conclusion

Our findings align with the results of landmark studies such as ISAT and BRAT, reaffirming that endovascular coiling offers superior functional outcomes compared with surgical clipping, despite an elevated risk of early rebleeding and occasional need for retreatment. While the mortality rate in our cohort was slightly higher—likely attributable to the greater proportion of poor-grade SAH cases—the majority of patients treated with endovascular coiling achieved favorable outcomes, consistent with those reported in larger, multicenter trials.

Challenges such as vasospasm, thromboembolic complications, and aneurysm recurrence remain significant factors impacting patient outcomes. These underscore the importance of close monitoring, individualized patient management, and the refinement of treatment strategies.

As endovascular techniques continue to advance, further research is essential to enhance procedural safety, reduce complications, and optimize long-term outcomes for patients with ruptured IAs. A continued focus on innovation and evidence-based practice will further solidify the role of endovascular coiling as the preferred treatment modality.

• References

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