Effect of Structural Remodeling (Retraction and Recoil) of the Pipeline Embolization Device on Aneurysm Occlusion Rate

Jou, Liang Der; Mitchell, Bartley D.; Shaltoni, Hashem; Mawad, Michel E.

doi:10.3174/ajnr.a3920

Cited by 16 publications

(8 citation statements)

References 24 publications

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“…This phenomenon usually is referred to as ''fish-mouthing'' and describes tapering of one or both ends of an FDS. 23 The finding can be visualized best in either DSA or FD-CT. In our survey, we found fish-mouthing in three cases (6.9%).…”

Section: Occlusion Rates and Patient Outcomementioning

confidence: 99%

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device

et al. 2019

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Background and purpose Flow-diverter stents are well-established for the treatment of cerebral aneurysms. Flow Redirection Endoluminal Device differs from other flow-diverter stents by its dual-layer design and has proved equality to other devices in numerous short-term surveys. However, follow-up data covering substantially more than one year are still limited for this device. We present our long-term experience with Flow Redirection Endoluminal Device. Materials and methods Seventy-eight patients harboring distal internal carotid artery (91%) or vertebrobasilar (9%) cerebral aneurysms treated with Flow Redirection Endoluminal Device with or without adjunctive coiling met the inclusion criteria. All cases were evaluated for aneurysm occlusion (according to Modified Raymond Roy Classification, MRRC), for flow-diverter stents patency and configuration and for procedure- and device-related morbidity and mortality. Results Mean follow-up interval was 36.9 ± 9.5 months (<30 months: n = 18; 31–42 months: n = 31; >42 months: n = 24). Total and subtotal aneurysm occlusion after six months was assessed in 92.0% (MRRC1 = 77.3%, MRRC2 = 14.7%, MRRC3a =2.7%, MRRC3b = 4.1%) and increased to 95.9% (MRRC1 = 90.5%, MRRC2 = 5.4%, MRRC3a = 2.7%). There was one case of aneurysm growth requiring early re-treatment. Procedure-related morbidity was observed in three cases (3.8%; one transient hemiparesis, one suspected foreign-body reaction, and one micro-wire perforation). There was no procedure- or device-related mortality. In-stent stenosis due to intimal hyperplasia was observed in two cases and fish-mouthing in three cases. Conclusions Our long-term data covering two to five years after flow diversion confirm that Flow Redirection Endoluminal Device is a safe and effective device for the treatment of cerebral aneurysms with progressive high aneurysm occlusion rates; recurrence rates were very low. Overall device-related morbidity was low and was not observed later than six months after intervention.

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Section: Occlusion Rates and Patient Outcomementioning

confidence: 99%

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device

et al. 2019

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“…5 The nominal MCR for the pipeline embolization device (PED) is 30 $ 35%; 6 that is, nearly one-third of ostium is covered by the device. The true MCR of a deployed PED may differ from the nominal MCR due to device oversize, 7 manipulation of device, 8 deformation caused by vessel curvature, 7 or aneurysm location. At the curved or dilated section of an artery, where intracranial aneurysms are often located, wires of the PED are farther apart, and the MCR is lower than those at other regions.…”

Section: Background and Purposementioning

confidence: 99%

Metal coverage ratio of pipeline embolization device for treatment of unruptured aneurysms: Reality check

Jou

Chintalapani²,

Mawad

2015

Interv Neuroradiol

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Background and purpose The metal coverage ratio (MCR) of a flow diverter influences the intra-aneurysmal hemodynamics; a high MCR will occlude an aneurysm early, while a low MCR may delay aneurysm occlusion. The true MCR of a pipeline embolization device (PED) could be lower due to oversize, device deformation, or aneurysm location. In this study deviation of the true MCR from the nominal MCR is assessed and whether their difference affects aneurysm occlusion rate is determined. Methods A total of 40 consecutive patients, each of them treated by one PED for their aneurysms at the internal carotid artery (ICA), were retrospectively analyzed. The DynaCT images of these deployed PEDs were used to determine their true dimensions and estimate three MCRs (local, mean, and nominal). These data were compared in two groups of patients who had different aneurysm outcomes at six months. Results The difference in the local MCR between two groups is small, but statistically significant (24.5% vs 21.6%, p = 05). The local MCR is consistently lower than the nominal MCRs (23.2% vs 30.2%, p < 0.001); however, the difference between the mean and local MCRs is small (23.9% vs 23.2%). Conclusions An expectation that a PED can achieve a MCR of 30% may not be reasonable. Device oversize and deformation during deployment lower the local MCR by 5–7%. A lowered MCR affects the aneurysm occlusion rate at six months.

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“…Moreover, Jou et al and Mut et al focused only on the stent oversizing and increasing flow [10,21]. However, in the study by Jou et al, 50% of the cases showed that the occlusion occurred at an oversizing of less than 1 mm.…”

Section: Clinical Aspect From the Results In Comparison With Those Ofmentioning

confidence: 99%

“…Jou et al, using the data from 14 aneurysms, statistically described that oversized artery by stenting may lead to the incomplete occlusion [21]. They showed that artery oversized by 1 mm did not yield occlusion.…”

Section: Clinical Aspect From the Results In Comparison With Those Ofmentioning

confidence: 99%

Changes in blood flow due to stented parent artery expansion in an intracranial aneurysm

Mori

Ohta

Matsuzawa

2014

THC

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BACKGROUND: Stent placement is thought to obstruct the inflow of blood to an aneurysm. However, we introduced parent artery expansion and demonstrated that this may reduce the blood flow by the stent. In our previous study using idealized shapes, the results showed that flow reduction was greater than 22.2%, even if the expansion rate was only 6%. Furthermore, the parent artery expansion is predominantly caused by the effect of flow reduction as compared to that of flow reduction due to the obstruction of flow under stent placement. However, a realistic shape is complex and the blood flow also becomes complex flow. It is not understood whether the results of flow in the idealized shape are reflective of flow from a realistic 3D model. Therefore, we examined the effect of parent artery expansion using a realistic model. OBJECTIVE: The aim is to clarify the effects of parent artery expansion on inflow rate, wall shear stress, and oscillatory shear index. METHODS: We used a patient-specific geometry of a human internal carotid artery with an aneurysm. The geometry of parent artery expansion due to oversized stent constructed based on the voronoi diagram. We performed calculations in the unsteady-state situations using constructed models. RESULTS: The complexity of the flow in the aneurysm decreases in case of expanded parent artery. The inflow rate decreases by 33.6% immediately after parent artery expansion alone without a stent. The effect of the parent artery expansion on flow reduction is larger than that of the obstruction flow by stent placement. In addition, wall shear stress and oscillatory shear index on the aneurysm wall decrease by change in blood flow due to the parent artery expansion. CONCLUSION: The effects of the parent artery expansion in a realistic aneurysm model with different stent lengths were evaluated on the basis of a numerical simulation. Although the flow was complex, the parent artery expansion with stent reduces the inflow to the aneurysm and wall shear stress and oscillatory shear index on the aneurysm. Therefore, we suggest that changes in the blood flow because of the parent artery expansion may be identified and, sometimes, is more effective than the obstruction flow due to the stent placement.

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Effect of Structural Remodeling (Retraction and Recoil) of the Pipeline Embolization Device on Aneurysm Occlusion Rate

Cited by 16 publications

References 24 publications

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device

Metal coverage ratio of pipeline embolization device for treatment of unruptured aneurysms: Reality check

Changes in blood flow due to stented parent artery expansion in an intracranial aneurysm

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