Ruptured aneurysms and the International Subarachnoid Aneurysm Trial (ISAT): What is known and what remains to be questioned

Understanding the meaning of care trials and why they are essential to good practice: An example from ISAT-2 on ruptured aneurysms

BACKGROUND

The research-care separation encourages clinicians to experiment without methods within the care context and trialists to design studies that may not properly inform practice. Care trials integrated into practice may solve these problems.

METHODS

We first discuss clinical decision-making for SAH patients prior to the ISAT trial which compared surgery with coiling, and how the ISAT results changed practices. We then review the ISAT-2 care trial and its impact on practice in the presence of clinical uncertainty.

RESULTS

Historically, ruptured aneurysms were treated with surgical clipping, with endovascular treatment limited to patients judged difficult to clip. ISAT was a turning point when it showed that many patients routinely treated with surgery would have better outcomes with coiling. With the proliferation of new endovascular devices, practices evolved and more patients could be treated endovascularly, but uncertainty regarding best management remained for numerous ruptured aneurysm patients that were not part of ISAT. Practicing under uncertainty, outside of a trial, is like performing research without methods within care. Without a scientific method of assessment, the notion of good surgical care is impossible to define, so ISAT-2 was designed. After 10 years, ISAT-2 remained inconclusive, but because the trial balanced risks for each patient, practicing within ISAT-2 provided the opportunity to realize that trial methods optimized care in real-time, long before conclusive results could be shown.

CONCLUSION

Care trials are integral to a good clinical practice, whether they provide final results or not. The research-care separation should be revised to encourage care research.

Multidimensional Comparison of Microsurgical Clipping and Endovascular Techniques for Anterior Communicating Artery Aneurysms: Balancing Occlusion Rates and Periprocedural Risks

Background and Objectives: The anterior communicating artery is a common location for intracranial aneurysms. Anterior communicating artery aneurysms (AcomA) pose a significant risk of rupture. Treatment options include microsurgical clipping and endovascular techniques, but the optimal approach remains controversial. This study aims to compare the outcomes of these two treatment modalities in a single-center patient cohort using a comprehensive matching process based on clinical and morphological parameters. Materials and Methods: A retrospective analysis was conducted on 1026 patients with 1496 intracranial aneurysms treated between 2000 and 2018. After excluding cases lacking 3D angiography or aneurysms in other locations or without treatment, 140 AcomA were selected. The study matched 24 surgically treated AcomA cases with 116 endovascularly treated cases based on 21 morphological and clinical criteria, including age, sex, Hunt and Hess score, and Fisher grade. Results: The microsurgical clipping group demonstrated a significantly higher rate of complete aneurysm occlusion compared to the endovascular group (p = 0.007). However, this was associated with a higher incidence of postoperative ischemic complications in the surgical group (13 out of 24 cases) compared to the endovascular group (2 out of 116 cases). Despite these complications, no significant differences were found in clinical outcomes at discharge or follow-up, as measured by the modified Rankin Scale (p > 0.999). Both groups had comparable rates of hydrocephalus, vasospasm, and delayed cerebral ischemia. Conclusions: Microsurgical clipping resulted in higher aneurysm occlusion rates but carried an increased risk of ischemic complications compared to endovascular treatment. Clinical outcomes were comparable between the two modalities, suggesting that treatment decisions should be individualized based on aneurysm characteristics and patient factors. Further prospective studies are warranted to optimize treatment strategies for AcomA.

Surgery or Endovascular Treatment in Patients with Anterior Communicating Artery Aneurysm: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Although randomized controlled trials have compared surgery versus endovascular treatment for intracranial aneurysms, the literature is sparse in terms of subgroup analysis for anterior communicating artery (ACoA) aneurysm management. This systematic review and meta-analysis sought to compare surgical versus endovascular treatment for ACoA aneurysms.

METHODS

Medline, PubMed, and Embase were searched from inception to December 12, 2022. Primary outcomes were post-treatment modified Rankin Scale (mRS) >2 and mortality. Secondary outcomes were aneurysm obliteration, retreatment and recurrence, rebleeding, technical failure, vessel rupture, aneurysmal subarachnoid hemorrhage-related hydrocephalus, symptomatic vasospasm, and stroke.

RESULTS

Eighteen studies yielded 2368 patients, from which 1196 (50.5%) and 1172 (49.4%) patients underwent surgery and endovascular treatment, respectively. The odds ratio (OR) of mortality was similar in total (OR = 0.92 [0.63-1.37], P = 0.69), ruptured (OR = 0.92 [0.62-1.36], P = 0.66), and unruptured cohorts (OR = 1.58 [0.06-39.60], P = 0.78). The OR of mRS > 2 was similar in total (OR = 0.75 [0.50-1.13], P = 0.17), ruptured (OR = 0.77 [0.49-1.20], P = 0.25), and unruptured cohorts (OR = 0.64 [0.21-1.96], P = 0.44). The OR of obliteration was higher with surgery in the total (OR = 2.52 [1.49-4.27], P = 0.0008) and ruptured cohorts (OR = 2.61 [1.33-5.10], P = 0.005) and unruptured group (OR = 3.46 [1.30-9.20], P = 0.01). The OR of retreatment was lower with surgery in the total (OR = 0.37 [0.17-0.76], P = 0.007) and ruptured cohorts (OR = 0.31 [0.11-0.89], P = 0.03), thought it was similar in the unruptured group (OR = 0.51 [0.08-3.03], P = 0.46). The OR of recurrence was lower with surgery in the total (OR = 0.22 [0.10, 0.47], P = 0.0001), ruptured (OR = 0.16 [0.03, 0.90], P = 0.04), and mixed (un) ruptured cohorts (OR = 0.22 [0.09-0.53], P = 0.0009). The OR of rebleeding in ruptured group was similar (OR = 0.66 [0.29-1.52], P = 0.33). The ORs of other outcomes were similar.

CONCLUSIONS

ACoA aneurysms may be safely treated with either surgery or endovascular treatment, although microsurgical clipping demonstrates higher obliteration rates and lower rates of retreatment and recurrence.

Ten-year analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial

OBJECTIVE

The authors present the 10-year results of the Barrow Ruptured Aneurysm Trial (BRAT) for saccular aneurysms. The 1-, 3-, and 6-year results of the trial have been previously reported, as have the 6-year results with respect to saccular aneurysms. This final report comparing the safety and efficacy of clipping versus coiling is limited to an analysis of those patients presenting with subarachnoid hemorrhage (SAH) from a ruptured saccular aneurysm.

METHODS

In the study, 362 patients had saccular aneurysms and were randomized equally to the clipping and the coiling cohorts (181 each). The primary outcome analysis was based on the assigned treatment group; poor outcome was defined as a modified Rankin Scale (mRS) score > 2 and was independently adjudicated. The extent of aneurysm obliteration was adjudicated by a nontreating neuroradiologist.

RESULTS

There was no statistically significant difference in poor outcome (mRS score > 2) or deaths between these 2 treatment arms during the 10 years of follow-up. Of 178 clip-assigned patients with saccular aneurysms, 1 (< 1%) was crossed over to coiling, and 64 (36%) of the 178 coil-assigned patients were crossed over to clipping. After the initial hospitalization, 2 of 241 (0.8%) clipped saccular aneurysms and 23 of 115 (20%) coiled saccular aneurysms required retreatment (p < 0.001). At the 10-year follow-up, 93% (50/54) of the clipped aneurysms were completely obliterated, compared with only 22% (5/23) of the coiled aneurysms (p < 0.001). Two patients had documented rebleeding, both died, and both were in the assigned and treated coiled cohort (2/83); no patient in the clipped cohort (0/175) died (p = 0.04). In 1 of these 2 patients, the hemorrhage was not from the target aneurysm but from an incidental basilar artery aneurysm, which was coiled at the same time.

CONCLUSIONS

There was no significant difference in clinical outcomes between the 2 assigned treatment groups as measured by mRS outcomes or deaths. Clinical outcomes in the patients with posterior circulation aneurysms were better in the coiling group at 1 year, but after 1 year this difference was no longer statistically significant. Rates of complete aneurysm obliteration and rates of retreatment favored patients who actually underwent clipping compared with those who underwent coiling.Clinical trial registration no.: NCT01593267 (clinicaltrials.gov).

Clinical Efficacy Between Microsurgical Clipping and Endovascular Coiling in the Treatment of Ruptured Poor-Grade Anterior Circulation Aneurysms

BACKGROUND

The treatment for patients with poor-grade aneurysms defined as World Federation of Neurosurgical Societies (WFNS) grade IV-V is still unclear and controversial. In this research, we compared the clinical efficacy and safety between clipping and coiling in the treatment of ruptured poor-grade anterior circulation aneurysms.

METHODS

We conducted a retrospective analysis of a hospital database. From January 2013 to May 2018, 94 patients who presented with poor-grade anterior circulation aneurysms were included. Preoperative baseline, postprocedure complications, and outcome (3-month and 6-month modified Rankin Scale scores) were analyzed. Multivariate logistic regression analysis was conducted to identify risk factors of short-term (in-hospital, 30-day) mortality.

RESULTS

A total of 21 (22%) patients died during short-term follow-up; there was a greater short-term mortality in coiling group (38% vs. 15%, P = 0.015). The incidence of delayed cerebral ischemia and intracranial infection in the clipping group was significantly greater than the coiling group: (33% vs. 14%, P = 0.045) and (68% vs. 41%, P = 0.016). However, coiling group had a greater rate of shunt-dependent hydrocephalus (21% vs. 6%, P = 0.035). Multivariate logistic regression analysis revealed cerebral vasospasm (odds ratio [OR], 9.22; P < 0.01), admission WFNS grade V (OR, 15.43; P < 0.01), coiling (OR, 5.92; P = 0.013), and postoperative aneurysm rebleeding (OR, 40.04; P = 0.01) would influence the mortality.

CONCLUSIONS

Patients with ruptured poor-grade anterior circulation aneurysms who undergo microsurgical clipping seem to have a lower short-term mortality. Cerebral vasospasm, WFNS grade V, and postoperative aneurysm rebleeding are associated with short-term mortality.

Practical Incidence of Complications and Degree of Patient Satisfaction After Endovascular Coil Embolization for Unruptured Intracranial Saccular Aneurysm Based on Patients' Surveys

OBJECTIVE

Endovascular treatment for unruptured intracranial aneurysms (UIAs) has been regarded as second to none management nowadays as the result of its proven efficacy and need for less-invasive treatment. Most researchers have focused on the anatomical outcome after endovascular treatment, so in this study we estimated the real incidence of untoward effect and degree of patients' satisfaction based on s survey.

METHODS

This retrospective study was approved by the institutional review board, and 112 patients treated for saccular UIAs were evaluated among a total of 135 patients. After informed consent was obtained, these patients were sent a questionnaire regarding treatment effectiveness, complications, and patient satisfaction. These data were collected and compared with angiographic and clinical outcome.

RESULTS

The response rate was 87.5% (98/112). Intracranial complications occurred in 10 aneurysms (10.2%): 7 ischemic and 3 hemorrhagic strokes. Other complications occurred in 30 patients (30.6%): 17 alopecia, 15 bleeding tendency, and 3 puncture-site complications. Overall, 89 (90.8%) patients reported being satisfied with their treatment. Patient satisfaction was closely correlated with clinically successful outcome of treatment.

CONCLUSIONS

Ninety percent of patients were satisfied with the results after endovascular treatment of UIAs. Endovascular coil embolization was effective and safe procedure, with high clinical success rate and degree of satisfaction.

Surgical or endovascular management of ruptured intracranial aneurysms: an agreement study

OBJECTIVE

Ruptured intracranial aneurysms (RIAs) can be managed surgically or endovascularly. In this study, the authors aimed to measure the interobserver agreement in selecting the best management option for various patients with an RIA.

METHODS

The authors constructed an electronic portfolio of 42 cases of RIA in which an angiographic image along with a brief clinical vignette for each patient were displayed. Undisclosed to the responders was that the RIAs had been categorized as International Subarachnoid Aneurysm Trial (ISAT) (small, anterior-circulation, non-middle cerebral artery location, n = 18) and non-ISAT (n = 22) aneurysms; the non-ISAT group also included 2 basilar apex aneurysms for which a high number of endovascular choices was expected. The portfolio was sent to 132 clinicians who manage patients with RIAs and circulated to members of an American surgical association. Judges were asked to choose between surgical and endovascular management, to indicate their level of confidence in the choice of treatment on a quantitative 0-10 scale, and to determine whether they would include the patient in a randomized trial in which both treatments are compared. Eleven clinicians were asked to respond twice at least 1 month apart. Responses were analyzed using kappa statistics.

RESULTS

Eighty-five clinicians (58 cerebrovascular surgeons, 21 interventional neuroradiologists, and 6 interventional neurologists) answered the questionnaire. Overall, endovascular management was chosen more frequently (n = 2136 [59.8%] of 3570 answers). The proportions of decisions to clip were significantly higher for non-ISAT (50.8%) than for ISAT (26.2%) aneurysms (p = 0.0003). Interjudge agreement was only fair (kappa 0.210, 95% CI 0.158-0.276) for all cases and judges, despite high confidence levels (mean score > 8 for all cases). Agreement was no better within subgroups of clinicians with the same specialty, years of experience, or location of practice or across capability groups (ability to clip or coil, or both). When agreement was defined as > 80% of responders choosing the same option, agreement occurred for only 7 of 40 cases, all of which were ISAT aneurysms, for which coiling was preferred.

CONCLUSIONS

Agreement between clinicians regarding the best management option was infrequent but centered around coiling for some ISAT aneurysms. Surgical clipping was chosen more frequently for non-ISAT aneurysms than for ISAT aneurysms. Patients with such an aneurysm might be candidates for inclusion in randomized trials.

Aneurysm treatment practice patterns for newly appointed dual-trained cerebrovascular/endovascular neurosurgeons: Comparison of open surgical to neuroendovascular procedures in the first 2 years of academic practice

Background:

The practice patterns of a hybrid open cerebrovascular/neuroendovascular (CVNV) neurosurgeon in early academic practice is unknown.

Methods:

We performed a multi-institutional retrospective cohort study of patients with cerebral aneurysms that were treated within the first 24 months of the neurosurgeon’s practice.

Results:

A total of 533 aneurysms were treated by the three senior authors within the first 24 months of their academic practice. Of these aneurysms, 172 were treated with microsurgical clipping, 191 with coiling, and 170 with flow diversion. Treatment in the setting of acute subarachnoid hemorrhage (SAH) occurred in 23% (122/533) of the aneurysms. Majority of the clipped aneurysms (70%, 121/172) were anterior cerebral artery (ACA), anterior communicating artery (ACOM), or middle cerebral artery (MCA) in location. In comparison, only 23% (82/361) of aneurysms treated with coiling or flow diversion therapy were ACA, ACOM, or MCA in location (P < 0.05). Additionally, majority of the flow diverted aneurysm (65%, 111/170) were cavernous or ophthalmic/paraophthalmic in location. During the second year of practice, there appeared to be a trend towards more aneurysms treated with neuroendovascular techniques (22% increase), particularly in flow diversion.

Conclusion:

Although the CVNV neurosurgeon treats cerebral aneurysms more commonly with neuroendovascular techniques, a third of the cerebral aneurysms are still selected for microsurgical clipping. Aneurysms located along the ACA/ACOM or MCA are the most frequent aneurysms reserved for microsurgical clipping. The CVNV neurosurgeon must be prepared to manage a high percentage of ACA/ACOM or MCA aneurysms microsurgically.

Treatment of Intracranial Aneurysms: Clipping Versus Coiling

Intracranial aneurysms (IAs) have an estimated incidence of up to 10 % and can lead to serious morbidity and mortality. Because of this, the natural history of IAs has been studied extensively, with rupture rates ranging from 0.5 to 7 %, depending on aneurysm characteristics. The spectrum of presentation of IAs ranges from incidental detection to devastating subarachnoid hemorrhage. Although the gold standard imaging technique is intra-arterial digital subtraction angiography, other modalities such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are being increasingly used for screening and treatment planning. Management of these patients depends upon a number of factors including aneurysmal, patient, institutional, and operator factors. The ultimate goal of treating patients with IAs is complete and permanent occlusion of the aneurysm sac in order to eliminate future hemorrhagic risk, while preserving or restoring the patient's neurological function. The most common treatment approaches include microsurgical clipping and endovascular coiling, and multiple studies have compared these two techniques. To date, three large prospective, randomized studies have been done: a study from Finland, International Subarachnoid Aneurysm Trial (ISAT), and the Barrow Ruptured Aneurysm Trial (BRAT). Despite differences in methodology, the results were similar: in patients undergoing coiling, although rates of rebleeding and retreatment are higher, the overall rate of poor outcomes at 12 months was significantly lower. As minimally invasive procedures and devices continue to be refined, endovascular strategies are likely to increase in popularity. However, as long-term outcome studies become available, it is increasingly apparent that they are complementary treatment strategies, with patient selection of critical importance.

Eleven Year's Single Center Experience of Endovascular Treatment of Anterior Communicating Artery Aneurysms: Focused on Digital Subtraction Angiography Follow-Up Results

Objective

Anterior communicating artery (AcomA) aneurysms represent the most common intracranial aneurysms and challenging to treat due to complex vascularity. The purpose of this study was to report our experience of endovascular treatment of AcomA aneurysms.

Methods

Between January 2003 and December 2013, we retrospectively reviewed the medical records of 134 AcomA aneurysm patients available more than 6 months conventional angiographic and clinical follow-up results. We focused on aneurismal or AcomA vascular characters, angiographic and clinical follow-up results, and retreatment.

Results

The rate of ruptured cases was 75.4%, and the small (<10 mm) aneurysms were 96.3%. Based on the subtypes defined by dominance of A1, 79 patients (59%) had contralateral A1 hypoplasia or agenesis. The immediate post-procedural angiography confirmed complete occlusion in 75.4%, partial occlusion in 24.6%. Procedure related complications were observed in 25 (18.6%) patients. Most of the adverse events were asymptomatic. Follow-up conventional angiography at ≥6 months was performed in all patients (mean 16.3 months) and major recanalization was noted in 6.7% and regrowth in one case. The aneurysm size (p=0.016), and initial treatment results (p=0.00) were statistically significant risk factors related to aneurysm recurrence. An overall improvement in mRS was observed during the clinical follow-up period and no rebleeding episode occurred.

Conclusion

This study demonstrated that endovascular treatment is an effective treatment modality for AcomA aneurysms with low morbidity. Patients should take long term clinical and angiographic follow-up in order to assess the recurrence and warrant retreatment, especially ruptured, large, and initially incomplete occluded aneurysms.

French collaborative group series on giant intracranial aneurysms: Current management

OBJECTIVES

Giant intracranial aneurysms represent a major therapeutic challenge for each surgical team. The aim of our study was to extensively review the French contemporary experience in treating giant intracranial aneurysms in order to assess the current management.

PATIENTS AND METHODS

This retrospective multicenter study concerned consecutive patients treated for giant intracranial aneurysms (2004-2008) in different French university hospitals (Bordeaux, Caen, Clermont-Ferrand, Lille, Lyon, Nice, Paris-Lariboisière, Rouen et Toulouse). Different variables were analyzed: the diagnostic circumstances, the initial clinical status based on the WFNS scale, aneurysmal features and exclusion procedure. At 6 months, the outcome was evaluated according to the modified Rankin Scale (mRS): favorable (mRS 0-2) and unfavorable (mRS 3-6). A multivariate logistic regression model included all the independent variables with P<0.25 in the univariate analysis (P<0.05).

RESULTS

A total of 79 patients with a mean age of 51.5 ± 1.6 years (median: 52 years; range: 16-79) were divided into two groups, with the ruptured group (n=26, 32.9%) significantly younger (P<0.05, Student's-t-test) than the unruptured group (n=53, 67.1%). After SAH, the initial clinical status was good in 12 patients (46.2%), and in the unruptured group, the predominant diagnosis circumstance was a pseudo-tumor syndrome occurring in 22 (41.5%). The first procedure of aneurysm treatment in the global population was endovascular in 42 patients (53.1%), microsurgical in 29 (36.7%) and conservative in 8 (10.2). An immediate neurological deterioration was reported in 38 patients (48.1%) after endovascular treatment in 19 (45.2% of endovascular procedures), after miscrosurgical in 15 (51.7% of microsurgical procedures) and after conservative in 4 (the half). At 6 months, the outcome was favorable in 45 patients (57%) and after multivariate analysis, the predictive factors of favorable outcome after management of giant cerebral aneurysm were the initial good clinical status in cases of SAH (P<0.002), the endovascular treatment (P<0.005), and the absence of neurological deterioration (P<0.006). The endovascular procedure was obtained as a predictive factor because of the low risk efficacy of indirect procedures, in particular a parent vessel occlusion.

CONCLUSION

The overall favorable outcome rate concerned 57% of patients at 6 months despite 53.8% of poor initial clinical status in cases of rupture. The predictive factors for favorable outcome were good clinical status, endovascular treatment and the absence of postoperative neurological deterioration. Endovascular treatment should be integrated into the therapeutic armenmatarium against giant cerebral aneurysms but the durability of exclusion should be taken into account during the multidisciplinary discussion by the neurovascular team.

International Subarachnoid Aneurysm Trial - ISAT part II: study protocol for a randomized controlled trial

BACKGROUND

The International Subarachnoid Aneurysm Trial (ISAT) demonstrated improved one-year clinical outcomes for patients with ruptured intracranial aneurysms treated with endovascular coiling compared to surgical clipping. Patients included in ISAT were mostly good grade subarachnoid hemorrhage (SAH) patients with small anterior circulation aneurysms. The purported superiority of coiling is commonly extrapolated to patients not studied in the original trial or to those treated using new devices not available at the time. Conversely, many patients are treated by clipping despite ISAT, because they are thought either to be better candidates for surgery, or to offer more durable protection from aneurysm recurrences. These practices have never been formally validated. Thus, for many ruptured aneurysm patients the question of which treatment modality leads to a superior clinical outcome remains unclear. METHODS/TRIAL DESIGN: ISAT II is a pragmatic, multicenter, randomized trial comparing clinical outcomes for non-ISAT patients with subarachnoid hemorrhage allocated to coiling or clipping. Inclusion criteria are broad. The primary end-point is the incidence of poor clinical outcome (defined as mRS >2) at one year, just as in ISAT. Secondary end-points include measures of treatment safety for a number of pre-specified subgroups, with efficacy end-points including the presence of a major recurrence at one year; 1,896 patients (862 each arm plus 10% losses) are required to demonstrate a significant difference between coiling and clipping, hypothesizing 23% and 30% poor clinical outcome rates, for coiling and clipping, respectively. The trial should involve at least 50 international centers, and will take approximately 12 years to complete. Analysis will be by intention-to-treat.

Endovascular therapeutic strategies in ruptured intracranial aneurysms

The aim of the present study was to evaluate endovascular techniques used currently which were not available at the time of ISAT inclusion period, such as balloon remodelling and flow-divertion, in order to assess whether these new technologies have improved the endovascular approach outcomes. We present a review of articles, published in major journals, with the aim to evaluate the efficacy and the safety of coiling with balloon remodelling for the treatment of ruptured aneurysms in comparison to coiling performed without such coadjutant techniques. Furthermore, we reviewed publications reporting on the treatment of ruptured aneurysms in the acute phase with the one of the most recent technologies available nowadays: the flow diverting stent. Looking at the recent literature the results regarding ruptured aneurysms treated with balloon assisted coiling (BAC) have shown an improvement in terms of anatomical results and morbi-mortality rates. Case series of ruptured middle cerebral artery (MCA) aneurysms treated by EVT report results similar to those obtained by surgical clipping. Several articles recently report encouraging results in treating ruptured dissecting and blister aneurysms with flow diverters. Questions regarding the best treatment available for ruptured aneurysms are yet to be answered. Hence there is a need for a subsequent trial aiming to answer these unresolved issues.

Clipping versus coiling for ruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Endovascular treatment has increasingly been used for aneurismal subarachnoid aneurismal hemorrhage. The aim of this analysis is to assess the current evidence regarding safety and efficiency of clipping compared with coiling.

METHODS

We conducted a meta-analysis of studies that compared clipping with coiling between January 1999 and July 2012. Comparison of binary outcomes between treatment groups was described using odds ratios (OR; clip versus coil).

RESULTS

Four randomized controlled trials and 23 observational studies were included. Randomized controlled trials showed that coiling reduced the 1-year unfavorable outcome rate (OR, 1.48; 95% confidence interval [CI], 1.24-1.76). However, there was no statistical deference in nonrandomized controlled trials (OR, 1.11; 95% CI, 0.96-1.28). Subgroup analysis revealed coiling yielded better outcomes for patients with good preoperative grade (OR, 1.51; 95% CI, 1.24-1.84) than for poor preoperative patients (OR, 0.88; 95% CI 0.56-1.38). Additionally, the incidence of rebleeding is higher after coiling (OR, 0.43; 95% CI, 0.28-0.66), corresponding to a better complete occlusion rate of clipping (OR, 2.43; 95% CI, 1.88-3.13). The 1-year mortality showed no significant difference (OR, 1.07; 95% CI, 0.88-1.30). Vasospasm was more common after clipping (OR, 1.43; 95% CI, 1.07-1.91), whereas the ischemic infarct (OR, 0.74; 95% CI, 0.52-1.06), shunt-dependent hydrocephalus (OR, 0.84; 95% CI, 0.66-1.07), and procedural complication rates (OR, 1.19; 95% CI, 0.67-2.11) did not differ significantly between techniques.

CONCLUSIONS

Coiling yields a better clinical outcome, the benefit being greater in those with a good preoperative grade than those with a poor preoperative grade. However, coiling leads to a greater risk of rebleeding. Well-designed randomized trials with special considerations to the aspect are needed.