Hemodynamic alterations after stent implantation in 15 cases of intracranial aneurysm

Fusiform versus Saccular Intracranial Aneurysms-Hemodynamic Evaluation of the Pre-Aneurysmal, Pathological, and Post-Interventional State

Minimally-invasive therapies are well-established treatment methods for saccular intracranial aneurysms (SIAs). Knowledge concerning fusiform IAs (FIAs) is low, due to their wide and alternating lumen and their infrequent occurrence. However, FIAs carry risks like ischemia and thus require further in-depth investigation. Six patient-specific IAs, comprising three position-identical FIAs and SIAs, with the FIAs showing a non-typical FIA shape, were compared, respectively. For each model, a healthy counterpart and a treated version with a flow diverting stent were created. Eighteen time-dependent simulations were performed to analyze morphological and hemodynamic parameters focusing on the treatment effect (TE). The stent expansion is higher for FIAs than SIAs. For FIAs, the reduction in vorticity is higher (Δ35-75% case 2/3) and the reduction in the oscillatory velocity index is lower (Δ15-68% case 2/3). Velocity is reduced equally for FIAs and SIAs with a TE of 37-60% in FIAs and of 41-72% in SIAs. Time-averaged wall shear stress (TAWSS) is less reduced within FIAs than SIAs (Δ30-105%). Within this study, the positive TE of FDS deployed in FIAs is shown and a similarity in parameters found due to the non-typical FIA shape. Despite the higher stent expansion, velocity and vorticity are equally reduced compared to identically located SIAs.

Stent-assisted coiling of intracranial carotid ophthalmic segment aneurysm segment aneurysms: Long-term follow-up from a single center

Background

To evaluate the efficacy of stent-assisted coiling (SAC) for the treatment of carotid ophthalmic segment aneurysm segment aneurysms (OSAs) of the internal carotid artery (ICA) through detailed long-term follow-up of a large patient cohort.

Methods

We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 ​at our center. Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale. The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up. The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.

Results

We enrolled 88 patients with 99 OSAs treated with coiling, of whom 76 were treated with SAC. The coiling procedures were successful in all 88 patients. Overall, complications occurred in 8 patients (9.1%). No procedure-related mortality was observed. 67 (76.1%) experienced immediate aneurysm occlusion at the end of the procedure. Long-term angiographic follow-up (18 months) was available in 45/88 aneurysms (51%) (average 18.7 ​± ​5.2 months). Four patients continued their follow-up for 5 years after initial aneurysm treatment. After a clinical follow-up time of 28.7 months (range, 12-51 months), 85 patients (95.5%) achieved favorable clinical outcomes (mRS scores of 0-2).

Conclusions

This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs. The procedural risks are low with relatively long-term effectiveness.

Stent-alone treatment of unruptured vertebral artery fusiform aneurysms: A comparison of flow diverter and conventional stents

Background

Treatment of vertebral artery fusiform aneurysms (VAFAs) is complex and controversial. This study aimed to compare the safety and efficacy between flow diverter and conventional stents in patients with VAFAs undergoing endovascular stent-alone treatment (SAT).

Methods

Thirty-six patients with 36 VAFAs who underwent SAT between January 2014 and December 2018 were retrospectively analyzed. Patient and aneurysm characteristics, procedural details, complications, and angiographic and clinical outcomes were compared between flow diverter stent patients (n = 22) and conventional stent patients (n = 14).

Results

More branches covered with stent were found in the conventional stent group (88.9 vs. 33.3%; p = 0.008). The number of stents placed was significantly higher in the conventional stent group (1.57 ± 0.76 vs. 1.09 ± 0.29; p = 0.016). The proportion of patients with significant or moderate stasis within the aneurysm immediately after stent placement was higher in the flow diverter stent group (95.5 vs. 57.1%; p = 0.004). The proportion of patients with complete obliteration or only a residual neck on follow-up angiography was significantly higher in the flow diverter stent group (86.3 vs 50.0%; p = 0.047). However, the incidence of parent artery stenosis or occlusion was also higher in the flow diverter stent group (27.3% vs. zero; p = 0.032). The rate of complications did not significantly differ between the groups.

Conclusions

SAT was safe and effective in patients with VAFAs. Flow diverter stents are associated with a significantly better complete occlusion rate than conventional stents; however, they are also associated with an increased risk of parent artery stenosis.

Risk factors for repeated recurrence of cerebral aneurysms treated with endovascular embolization

Purpose

To explore the risk factors of recurrence after second endovascular embolization of recurrent aneurysms and the characteristics of recurrent refractory aneurysms to help clinical decision-making.

Materials and methods

Forty-nine patients with recurrent aneurysms who underwent repeated embolization were retrospectively enrolled and divided into the recurrent and non-recurrent group. The risk factors of recurrence, complications and follow-up results of repeated embolization, and characteristics of recurrent refractory aneurysms were analyzed.

Results

Among the 49 patients with the second embolization, 5 were lost to follow-up, 9 recurred, and 35 did not. Univariate analysis showed that aneurysm size (P = 0.022), aneurysm classification (P = 0.014), and Raymond-Roy grade after the second embolization (P = 0.001) were statistically different between the two groups. Multivariate analysis demonstrated the Raymond-Roy grade as an independent risk factor for the recurrence of aneurysms after the second embolization (P = 0.042). The complication rate after the second embolization was 4%. There were five recurrent refractory aneurysms with an average aneurysm size of 23.17 ± 10.45 mm, including three giant aneurysms and two large aneurysms. To achieve complete or near-complete embolization of the recurrent refractory aneurysms, multiple treatment approaches were needed with multiple stents or flow diverting devices.

Conclusion

Aneurysm occlusion status after the second embolization is an independent risk factor for the recurrence of intracranial aneurysms. Compared with near-complete occlusion, complete occlusion can significantly reduce the risk of recurrence after second embolization. In order to achieve complete or near-complete occlusion, recurrent refractory aneurysms need multiple treatments with the use of multiple stents or flow diverting devices.

Numerical Assessment of the Risk of Abnormal Endothelialization for Diverter Devices: Clinical Data Driven Numerical Study

Numerical modeling is an effective tool for preoperative planning. The present work is devoted to a retrospective analysis of neurosurgical treatments for the occlusion of cerebral aneurysms using flow-diverters and hemodynamic factors affecting stent endothelization. Several different geometric approaches have been considered for virtual flow-diverters deployment. A comparative analysis of hemodynamic parameters as a result of computational modeling has been carried out basing on the four clinical cases: one successful treatment, one with no occlusion and two with in stent stenosis. For the first time, a quantitative assessment of both: the limiting magnitude of shear stresses that are necessary for the occurrence of in stent stenosis (MaxWSS > 1.23) and for conditions in which endothelialization is insufficiently active and occlusion of the cervical part of the aneurysm does not occur (MaxWSS < 1.68)—has been statistacally proven (p < 0.01).

Hemodynamic analysis and implantation strategies of delayed intracranial aneurysm rupture after flow diverter treatment

BACKGROUND

Delayed aneurysm rupture after flow diverters (FDs) is a serious complication which mechanism remains unclear. The hemodynamics of FDs with proximal or distal densification implantation strategies have rarely been reported. In this study, we investigated not only the hemodynamic factors involved in postoperative rupture, but also the hemodynamic effects of different FDs implantation strategies on avoiding this complication.

METHODS

We selected 2 internal carotid artery (ICA) aneurysms with similar morphological characteristics, both of which were treated with FDs but had opposite therapeutic outcomes (Case 1, ruptured after FD treatment; Case 2, recovered). The FDs strategies we designed were strategy A [with homogeneous 30% metal coverage ratio (MCR)], strategy B (with distal densification of 40% and proximal 30% MCR) and strategy C (with proximal densification of 40% and distal 30% MCR). Virtually FDs deployment and computational fluid dynamics (CFD) method were performed to simulate FDs implantation strategies and analyze the hemodynamics associated with postoperative rupture.

RESULTS

After FDs implantation, the velocity of blood entering the aneurysm decreased (Case 1, 25.4%; Case 2, 30.6%), but the inflow jet impingement still existed in Case 1. The overall WSS decreased similarly in both cases, but the high WSS region hardly diminished in Case 1. For overall wall pressure, Case 2 decreased slightly but increased in Case 1. Of the three FDs implantation strategies, strategy C had the best hemodynamic effects, including the maximum blood velocity reduction and a tendency to form a more stable flow pattern, the maximum reduction rate of overall WSS and the effective diminish of high WSS area as well as the overall decrease of wall pressure.

CONCLUSIONS

Not significant decrease of blood flow velocity entering the aneurysm adding persistent impact of inflow jet impingement, high WSS area that did not diminish and abnormal increase of pressure on the aneurysm wall may be causative of postoperative rupture and bleeding of ICA aneurysms. In addition, the hemodynamic effects were favorable when the FD was improved to proximal densification, which may reduce the risk of delayed aneurysm rupture following FDs treatment.

KEYWORDS

Delayed rupture; flow diverter (FD); computational fluid dynamics (CFD); intracranial aneurysm (IAs); internal carotid artery (ICA).

Computational Study of Hemodynamic Changes Induced by Overlapping and Compacting of Stents and Flow Diverter in Cerebral Aneurysms

Purpose: The flow diversion effect of an intracranial stent is closely related to its metal coverage rate (MCR). In this study, the flow diversion effects of Enterprise and low-profile visualized intraluminal support (LVIS) stents are compared with those of a Pipeline flow diverter, focusing on the MCR change. Moreover, the changes in the flow diversion effect caused by the additional manipulations of overlapping and compaction are verified using computational fluid dynamics (CFD) analysis. Methods: CFD analysis was performed using virtually generated stents mounted in an idealized aneurysm model. First, the flow diversion effects of single Enterprise, LVIS, and Pipeline devices were analyzed. The Enterprise and LVIS were sequentially overlapped and compared with a Pipeline, to evaluate the effect of stent overlapping. The effect of compacting a stent was evaluated by comparing the flow diversion effects of a single and two compacted LVIS with those of two overlapped, uncompacted LVIS and uncompacted and compacted Pipeline. Quantitative analysis was performed to evaluate the hemodynamic parameters of energy loss, average velocity, and inflow rate. Results: Statistically significant correlations were observed between the reduction rates of the hemodynamic parameters and MCR. The single LVIS without compaction induced a reduction in all the hemodynamic parameters comparable to those of the three overlapped Enterprise. Moreover, the two overlapped, uncompacted LVIS showed a flow diversion effect as large as that induced by the single uncompacted Pipeline. Compacted stents induced a better flow diversion effect than uncompacted stents. The single compacted LVIS induced a flow diversion effect similar to that induced by the two uncompacted LVIS or single uncompacted Pipeline. Conclusions: The MCR of a stent correlates with its flow diversion effect. Overlapping and compaction can increase the MCR of an intracranial stent and achieve a flow diversion effect as large as that observed with a flow diverter.

Overlapping stent-assisted coil embolization for vertebrobasilar dissecting aneurysms: a single-center study

Effective treatment strategies for vertebrobasilar dissecting aneurysms (VBDAs) remain controversial due to their high morbidity and mortality. The aim of the present study was to evaluate the efficacy of overlapping stent-assisted coil embolization (OSCE) in VBDA patients. A total of 42 patients with VBDA were retrospectively examined by OSCE from May 2015 to August 2019. Patients' clinical and radiological parameters were assessed at discharge and during interim follow-up. Safety, technical feasibility and follow-up clinical and imaging observations for therapy were also evaluated retrospectively. The average age of the 42 patients who underwent OSCE was 54 years (range 33 to 74 years). Overlapping stents were successfully implanted in all patients after coil embolism. Overall clinical results were effective (score on a modified Rankin scale from 0 to 2) in all patients. In the meantime, all patients had favorable outcomes when evaluating telephone calls or digital subtractive angiography (DSA) imaging. Among 42 patients, one patient died due to a perioperative rupture. All the remaining 41 patients had a good prognosis during the follow-up telephone call, with a median follow-up of 28 months (range, 2 to 55 months). The total number of DSA recurrences was 20. Subsequent DSA results showed that all aneurysms were completely occluded while in only one case the parent artery of the aneurysm was completely closed. OSCE in VBDAs patients is safe and effective. This technique showed favorable results in clinical and imaging follow-ups for non-ruptured and ruptured VBDAs.

Stent-Induced Vascular Remodeling in Two-Step Stent-Assisted Coiling Treatment of Brain Aneurysms: A Closer Look Into the Hemodynamic Changes During the Stent Healing Period

Stenting has become an important adjunctive tool for assisting coil embolization in complex-shaped intracranial aneurysms. However, as a secondary effect, stent deployment has been related to both immediate and delayed remodeling of the local vasculature. Recent studies have demonstrated that this phenomenon may assume different roles depending on the treatment stage. However, the extent of such event on the intra-aneurysmal hemodynamics is still unclear; especially when performing two-step stent-assisted coiling (SAC). Therefore, we performed computational fluid dynamics (CFD) analysis of the blood flow in four bifurcation aneurysms focusing on the stent healing period found in SAC as a two-step maneuver. Our results show that by changing the local vasculature, the intra-aneurysmal hemodynamics changes considerably. However, even though changes do occur, they were not consistent among the cases. Furthermore, by changing the local vasculature not only the shear levels change but also the shear distribution on the aneurysm surface. Additionally, a geometric analysis alone can mislead the estimation of the novel hemodynamic environment after vascular remodeling, especially in the presence of mixing streams. Therefore, although the novel local vasculature might induce an improved hemodynamic environment, it is also plausible to expect that adverse hemodynamic conditions might occur. This could pose a particularly delicate condition since the aneurysm surface remains completely exposed to the novel hemodynamic environment during the stent healing period. Finally, our study emphasizes that vascular remodeling should be considered when assessing the hemodynamics in aneurysms treated with stents, especially when evaluating the earlier stages of the treatment process.

Hemodynamic Effect of the Last Finishing Coils in Packing the Aneurysm Neck

Background: Using the finishing coils to densely pack the aneurysm neck is necessary. However, the exact hemodynamic effect of finishing coils in packing the aneurysm neck is unknown.

Objective: To evaluate the hemodynamic characteristics of finishing coils to densely pack the aneurysm neck, using finite element method simulation.

Methods: A computational study was performed based on a 44-year-old female patient with an unruptured wide-necked carotid-ophthalmic artery aneurysm treated with low-profile visualized intraluminal support stent-assisted coil embolization. Four computational fluid dynamics models including pre-treatment, post-stenting, common stent-assisted coil embolization (SACE), and common SACE with finishing coils were evaluated qualitatively and quantitatively.

Results: Compared with the baseline of pretreatment model (100%), sac-averaged velocity in post-stenting, common SACE, and common SACE with finishing coil models decreased to 95.68%, 24.38%, and 13.20%, respectively; high flow volume (>0.1 m/s) around the aneurysm neck decreased to 92.19%, 9.59%, and 5.57%, respectively; and mean wall shear stress increased or decreased to 107%, 25.94%, and 23.89%, respectively.

Conclusion: Finishing coils to densely pack the aneurysm neck can generate favorable hemodynamic modifications, which may decrease the recurrence.

Hemodynamic differences by increasing low profile visualized intraluminal support (LVIS) stent local compaction across intracranial aneurysm orifice

BACKGROUND

The Low-profile Visualized Intraluminal Support device (LVIS) has been successfully used to treat cerebral aneurysm, and the push-pull technique has been used clinically to compact the stent across aneurysm orifice. Our aim was to exhibit the hemodynamic effect of the compacted LVIS stent.

METHODS

Two patient-specific aneurysm models were constructed from three-dimensional angiographic images. The uniform LVIS stent, compacted LVIS and Pipeline Embolization Device (PED) with or without coil embolization were virtually deployed into aneurysm models to perform hemodynamic analysis. Intra-aneurysmal flow parameters were calculated to assess hemodynamic differences among different models.

RESULTS

The compacted LVIS had the highest metal coverage across the aneurysm orifice (case 1, 46.37%; case 2, 67.01%). However, the PED achieved the highest pore density (case 1, 19.56 pores/mm²; case 2, 18.07 pores/mm²). The compacted LVIS produced a much higher intra-aneurysmal flow reduction than the uniform LVIS. The PED showed a higher intra-aneurysmal flow reduction than the compacted LVIS in case 1, but the results were comparable in case 2. After stent placement, the intra-aneurysmal flow was further reduced as subsequent coil embolization. The compacted LVIS stent with coils produced a similar reduction in intra-aneurysmal flow to that of the PED.

CONCLUSIONS

The combined characteristics of stent metal coverage and pore density should be considered when assessing the flow diversion effects of stents. More intra-aneurysmal flow reductions could be introduced by compacted LVIS stent than the uniform one. Compared with PED, compacted LVIS stent may exhibit a flow-diverting effect comparable to that of the PED.

Numerical studies of hemodynamic alterations in pre- and post-stenting cerebral aneurysms using a multiscale modeling

The aim of this work was to use a multiscale modeling to study the influence of stent deployment, with generic stents, on flow distributions within the vascular network and the hemodynamic alterations within the cerebral aneurysms pre- and post-stenting. To achieve this goal, two image-based anatomical cerebral aneurysm models were reconstructed along with the respective aneurysms post-stenting models after deploying a 16- or 24-wire stent. The investigation results revealed that the stent may increase the local pressure resistance resulting in flow alterations. The hemodynamic parameters demonstrated stent placement can reduce the intra-aneurysmal pressure, decrease wall shear stress (WSS) at the neck region, and increase blood turnover time for aneurysm case I (sidewall aneurysm). These findings are consistent with the trends of hemodynamic changes reported previously. However, aneurysm case II (bifurcation aneurysm) showed gradually increased intra-aneurysmal pressure and the pressure at the neck region, decreased WSS over the sac surface, and enhanced flow vortices within the aneurysm. When simulating the hemodynamics of pre- and post-stenting aneurysms for a patient using measured flow waveforms, the flow alteration induced by the stent deployment may affect the hemodynamic predictions for the post-stenting aneurysm. Thus, the remeasurement of boundary conditions once the morphology of the aneurysm is deformed is needed in follow-up studies with a focus on aneurysm growth and stent deployment.

Evidence for non-Newtonian behavior of intracranial blood flow from Doppler ultrasonography measurements

Computational fluid dynamics (CFD) studies of intracranial hemodynamics often use Newtonian viscosity model to close the shear rate term in the Navier-Stokes equation. This is based on a commonly accepted hypothesis which state that non-Newtonian effects can be neglected in intracranial blood flow. This study aims to examine the validity of such hypothesis to guide future CFD studies of intracranial hemodynamics. Doppler ultrasonography (DUS) measurements of systolic and diastolic vessel diameter and blood velocity were conducted on 16 subjects (mean age 50.6). The measurements were conducted on the internal carotid (ICA), middle cerebral (MCA), and anterior communicating (AComA) arteries. Systolic and diastolic wall shear stress (WSS) values were calculated via the Hagen-Poiseuille exact solution using Newtonian and three different non-Newtonian models: namely Carreau, power-law and Herschel-Bulkley models. The Weissenberg-Rabinowitsch correction for blood shear-thinning viscosity was applied to the non-Newtonian models. The error percentage between the two sets of models was calculated and discussed. The Newtonian hypothesis was tested statistically and discussed using paired t tests. Significant differences (P < 0.0001) were found between the Newtonian and non-Newtonian WSS in ICA. In MCA and AComA, similar differences were found except in the systole and diastole for the Herschel-Bulkley and power-law models (P = 0.0669, P = 0.7298), respectively. The error between the Newtonian and non-Newtonian models ranged from - 27 to 30% (0.2 to 2.2 Pa). These values could affect the physical interpretation of IA CFD studies. Evidence suggests that the Newtonian assumption may be inappropriate to investigate intracranial hemodynamics. Graphical abstract The WSS estimation error resulting from using the Newtonian assumption compared to three non-Newtonian models for ICA, MCA, and AComA in systole and diastole conditions, based on TCCD measurements of 16 subjects. The error due to the Newtonian assumption ranged from 0.2 to 2.2 Pa (- 27 to 30%). These values could affect the physical interpretation of IA CFD studies.

Endovascular stent-induced alterations in host artery mechanical environments and their roles in stent restenosis and late thrombosis

Cardiovascular stent restenosis remains a major challenge in interventional treatment of cardiovascular occlusive disease. Although the changes in arterial mechanical environment due to stent implantation are the main causes of the initiation of restenosis and thrombosis, the mechanisms that cause this initiation are still not fully understood. In this article, we reviewed the studies on the issue of stent-induced alterations in arterial mechanical environment and discussed their roles in stent restenosis and late thrombosis from three aspects: (i) the interaction of the stent with host blood vessel, involve the response of vascular wall, the mechanism of mechanical signal transmission, the process of re-endothelialization and late thrombosis; (ii) the changes of hemodynamics in the lumen of the vascular segment and (iii) the changes of mechanical microenvironment within the vascular segment wall due to stent implantation. This review has summarized and analyzed current work in order to better solve the two main problems after stent implantation, namely in stent restenosis and late thrombosis, meanwhile propose the deficiencies of current work for future reference.

A New Imaging Tool for Realtime Measurement of Flow Velocity in Intracranial Aneurysms

With modern imaging modalities of the brain a significant number of unruptured aneurysms are detected. However, not every aneurysm is prone to rupture. Because treatment morbidity is about 10% it is crucial to identify unstable aneurysms for which treatment should be discussed. Recently, new imaging tools allow analysis of flow dynamics and wall stability have become available. It seems that they might provide additional data for better risk profiling. In this study we present a new imaging tool for analysis of flow dynamics, which calculates fluid velocity in an aneurysm (Phillips Electronics, N.V.). It may identify regions with high flow and calculate flow reduction after stenting of aneurysms. Contrast is injected with a stable injection speed of 2 mL/sec for 3 sec. Two clinical cases are illustrated. Velocity in aneurysms and areas of instability can be identified and calculated during angiography in real-time. After stenting and flow diverter deployment flow reduction in the internal carotid aneurysm was reduced by 60% and there was a reduction of about 65% in the posterior cerebral artery in the second case we are reporting. The dynamic flow software calculates the flow profile in the aneurysm immediately after contrast injection. It is a real-time, patient specific tool taking into account systole, diastole and flexibility of the vasculature. These factors are an improvement as compared to current models of computational flow dynamics. We think it is a highly efficient, user friendly tool. Further clinical studies are on their way.

Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters

Treatment of intracranial aneurysms (IAs) has been revolutionized by the advent of endovascular Flow Diverters (FDs), which disrupt blood flow within the aneurysm to induce pro-thrombotic conditions, and serves as a scaffold for endothelial ingrowth and arterial remodeling. Despite good clinical success of FDs, complications like incomplete occlusion and post-treatment rupture leading to subarachnoid hemorrhage have been reported. In silico computational fluid dynamic analysis of the pre- and post-treated geometries of IA patients can shed light on the contrasting blood hemodynamics associated with different clinical outcomes. In this study, we analyzed hemodynamic modifications in 15 IA patients treated using a single FD; 10 IAs were completely occluded (successful) and 5 were partially occluded (unsuccessful) at 12-month follow-up. An in-house virtual stenting workflow was used to recapitulate the clinical intervention on these cases, followed by CFD to obtain pre- and post-treatment hemodynamics. Bulk hemodynamic parameters showed comparable reductions in both groups with average inflow rate and aneurysmal velocity reduction of 40.3% and 52.4% in successful cases, and 34.4% and 49.2% in unsuccessful cases. There was a substantial reduction in localized parameter like vortex coreline length and Energy Loss for successful cases, 38.2% and 42.9% compared to 10.1% and 10.5% for unsuccessful cases. This suggest that for successfully treated IAs, the localized complex blood flow is disrupted more prominently by the FD as compared to unsuccessful cases. These localized hemodynamic parameters can be potentially used in prediction of treatment outcome, thus aiding the clinicians in a priori assessment of different treatment strategies.

Combined use of a pCONus and a Solitaire stent: Report of two cases

Objective The aim of this study was to report our initial experience of the use of the pCONus neck protection device in conjunction with the Solitaire AB stent to assist in the endovascular management of complex intracranial aneurysms with arteries arising from both the neck and the dome of the aneurysm. Methods Two patients with unruptured aneurysms underwent elective endovascular management of their aneurysms, one arising from the middle cerebral artery bifurcation and one from the anterior communicating artery. Both aneurysms had vessels arising from the neck and dome of the aneurysm. We present the strategy involved to protect all the arterial branches and coil occlude the aneurysm, the angiographic appearances and clinical status of the patients. Results Both cases involved the combined use of a pCONus and Solitaire stent. The parent vessel and efferent branches were all preserved with exclusion of the aneurysm from the circulation. There were no intraoperative complications. One patient developed mild transient symptoms 24 hours post procedure, which had resolved completely on discharge. Conclusion The use of the pCONus in conjunction with the Solitaire stent is a useful combination when dealing with complex wide-necked aneurysms with arteries derived from the fundus of the aneurysm.