Computational Simulation of Flow at the Bleb of Aneurysms and Confirmation by Clinical Angiogram Fukasaku K, Negoro M, Konishi Y, Noda S, Himeno R, Yokota Y, Fukui K, Nara I and Shiokawa Y Computational Biomechanics, RIKEN Department of Neurosurgery, Fujita Health University Department of Neurosurgery, Korin University Department of Neurosurgery, Himon’ya Hospital Department of Neurosurgery, Fukui Neurosurgical Clinic

Time Consuming Calculation Steady Flow 3D Data: Single Helical CTA Segmentation: few weeks Calculation: few weeks Total: 2 Months Pulsatile Flow 3D Data: 3D DSA or MRA Segmentation: less than an hour Calculation: 20 hours/cycle Total: One Week (10 Cycles)

CFD for Clinical Use Which Imaging Modalities? Same results from the same data Immediate Result for Ruptured Cases Results within 2 or 4 weeks for Unruptured Cases (or a few days?) Detect Common Risky Finding by CFD. Visualize the Findings by DSA or Others. Validation for the Results of CFD

Risky Aneurysms Large Irregular Shape Bleb Location Gender, smoking, hypertension, family history, multiple....

Risky Aneurysms What is the Common Risky Findings from CFD? How to Validate?? Bled and Slow Flow DSA

CFD for a Lethal AC Aneurysm with Bleb

CFD for a Lethal AC Aneurysm

Current System without Surface polygon

Voxcel Model Use Medical Images Directly after Cleaning No Need for Mesh Generation Medical ImagesLaminated Images VOF Parameter

DICOM or RAW Noise Reduction Preprocessor Boundary Condition Solver Visualisation (Visio)

Approximation Voxcel (Approximation Level 0) VOF (Approximation Level 1) VOF+AOF (Approximation Level 2) Volume Ratio in the Voxcel Surface Area Ratio

Image Data Acquisition Clinical Necessity 20 min hr Noise Reduction30 min ?? Preprocessing30 min ?? Solver pixcels ^3 Visualization as you like （ 2 hrs? ）

CDF for MC Aneurysm with Double Blebs

CFD for IC Aneurysm with Blebs

Common Characteristic Slow or Poor Flow at Bleb Slow Flow Visualisation by DSA? or Other Modalities

Poor Flow at Bleb

Flow at Bleb

Visualization by DSA 10 ml at 2 ml/sec, 7.5 Fr 10 sec, Integris Allura (II), Philips

Visualization Flow at Bleb by DSA 10 ml at 2 ml/sec, 7.5 Fr 10 sec, Integris Allura (II), Philips

Visualization Flow at Bleb by CFD

Visualization Flow at Bleb by DSA

Characteristic Flow Pattern at the Bleb/Risky Part Slow Inflow, Slow Wash Out Flow Pattern at Bleb Slow Flow, Low Shear Visualized by Proper DSA (7.5 fr/sec)

at bleb Slow flow degenerate wall middle cerebral aneurysm Visible blood flow through thin vessel wall. May be high speed flow destroy arterial wall.... Soon rupture

A Com Aneurysm High Risk of Rupture Possible Miss Diagnosis without “Matas” Maneuver = Poor Flow Inflow from both A1s Balanced Pressure to Decrease Flow.... Poor Flow, High Pressure

Incidental ACom Aneurysm

Case of Flow Diverter

Conflict of Flow Diverting Stent VISC09, Ohta M, Tohoku Univ Bery Naeurysm at Fenestrated Basilar Trunk. Flow Diverting Stent Remarkable Decrese of Flow Degeration of Aneurysm Wall Rupture ??? Induce Thrombosis CURE Low Share

Conclusion Slow/Poor Flow at Bleb as the Result of CFD Validated by DSA Flow at Bleb Slow Flow Low Shear Leads to Degeneration and then Rupture

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