AUTOMATED PRE-PROCESSING FOR HIGH QUALITY MULTIPLE VARIANT CFD MODELS OF A CITY-CLASS CAR
CFD Analysis for Automated Distal Anastomosis in Coronary
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Toe Heel Anvil Inser.on hole DeBakey Heart & Vascular Center (Houston, TX, USA) Operator: Cardiac Resident (100 case/ year) Model: Silicone vascular model, Wall thickness 0.5mm, D in =2.0mm Anastomosis at non-beating condition Apparatus TDM1300-IS (Yamato Kagaku, Japan) Resolution 50μm Voltage 70 kV Current 18μA Measurement Materials Analysis Steady flow analysis (ANSYS FLUENT) Working fluid Density：1160 kg/m 3 Viscosity ：0.0053 Pa・s Vessel Wall Solid (No Slip) Boundary conditions Evaluation Energy loss (μW), Cross-sectional area (mm 2 ) Graft：Flow volume 100 ml /min Proximal：100% Occlusion Distal：0 Pa ( ) ∫ ⋅ − ⋅ = T out out in in loss dt Q P Q P E 7.80 mm 2 1.6 mm 2 Energy loss 489.8 μW Velocity (m/s) 489.8 93.1 111.7 63.2 0 100 200 300 400 500 600 1st 2nd 1st 2nd Energy loss uW Auto suture Hand suture CFD Analysis for Automated Distal Anastomosis in Coronary Bypass Grafting: Need of In-vitro Training with Quantitative anastomotic Quality Assessment Young-Kwang Park, PhD 1 , Tadashi Motomura, MD, PhD 2 , Daisuke Ogawa 1 , Naohiko Kanemitsu, MS 1 , Gustavo Guajardo Salinas, MD 2 , Basel Ramlawi, MD, MMSc 2 , Mitsuo Umezu, PhD 1 , Mahesh Ramchandani, MD 2 1: TWIns, Waseda University, Tokyo, Japan 2: Cardiovascular Surgery & Thoracic Transplant, The Methodist Hospital Debakey Heart & Vascular Center, Houston, TX, United States, 77030 International Society for Minimally Invasive Cardiothoracic Surgery, Annual Scientific Meeting 2013 in Czech Republic Abstract Objective: Proximal automated suture devices are clinically used for off-pump coronary bypass grafting (OPCAB). Beyond standard OPCAB methods, an even less invasive approach has been applied, so-called “minimally invasive coronary artery bypass (MICS-CAB).” Due to the small surgical field in MICS-CAB, distal anastomoses in the circumflex or right coronary artery territory are technically challenging. Distal coronary automated anastomosis devices are clinically available and offer a promising option for the MICS-CAB operation. However, in vitro imaging analysis and the need for device deployment training are not well investigated. This study aims to assess morphological and hemodynamic characteristics of automated distal coronary artery anastomotic device compared with hand-sewn anastomoses using rapid computational fluid dynamics (CFD) analysis and multiple quantitative analyses. Materials and Methods: A tissue-mimicking silicone-rubber coronary model was used by a cardiac surgeon to create 2 hand-sewn models and 2 automated suture models each. For morphological assessment, minimum cross-sectional area (CSA) was measured by Micro CT scan with a special 50 µm resolution. Energy loss value was calculated using CFD techniques to assess the degree of anastomotic stenosis (where high energy loss represents high stenosis). These parameters were compared for the first and second automated suture models. Results: Inadequate installation of automated device encompassed poor anastomosis with high energy loss (489.8 µW) and a narrowed anastomosis (1.64 mm 2 ), as opposed to hand suture group (mean energy loss of 87.5 µW and mean CAS of 9.4 mm 2 ). In contrast, properly installed graft to the automated device significantly improved energy loss (93.1 µW, 81% improvement) and a CSA (7.80 mm 2 , 475% improvement). This result was comparable with hand sewn group and suggested importance of graft installation training as well as final deployment techniques. Conclusions: Automated suturing of distal anastomoses showed equivalent anastomotic qualities compared with conventional hand suture anastomosis. As well as hand sewing skills, it is equally important to maintain consistent anastomosis quality for automated device. Particularly, graft installation and automated clip deployment maneuvering may require systematic in-vitro training and imaging/quantitative assessment prior to device clinical implementation. Introduction Conclusions Methods Results Beating heart simulator Fat tissue Graft vessel Coronary artery Coronary artery model Auto suture n=2 Hand suture n=2 1mm 14.4 mm 2 1mm 4.5 mm 2 1mm 7.8mm 2 1mm 93.1 μW 111.7 μW 63.2 μW Cross Sectional Area Auto suture Hand suture Micro focus CT scanner Scan 3D Rendering Mesh CFD Analysis Automated suturing of distal anastomoses showed equivalent anastomotic qualities compared with conventional hand suture anastomosis. As well as hand sewing skills, it is equally important to maintain consistent anastomosis quality for automated device. Particularly, graft installation and automated clip deployment maneuvering may require systematic in-vitro training and imaging/quantitative assessment prior to device clinical implementation. This study aims to assess morphological and hemodynamic characteristics of automated distal coronary artery anastomotic device compared with hand-sewn anastomoses using rapid computational fluid dynamics (CFD) analysis and multiple quantitative analyses.
Transcript of CFD Analysis for Automated Distal Anastomosis in Coronary
Toe
Heel Anvil
Inser.on hole
DeBakey Heart & Vascular Center !(Houston, TX, USA)!Operator: Cardiac Resident (100 case/ year)!Model: Silicone vascular model, Wall thickness 0.5mm, Din=2.0mm !Anastomosis at non-beating condition!
Apparatus TDM1300-IS!(Yamato Kagaku, Japan)
Resolution 50μm Voltage 70 kV Current 18μA!
Measurement
Materials
Analysis ! Steady flow analysis (ANSYS FLUENT)!Working fluid Density：1160 kg/m3 Viscosity ：0.0053 Pa・s!Vessel Wall Solid (No Slip) Boundary conditions
!
Evaluation Energy loss (μW), Cross-sectional area (mm2)!
Graft：Flow volume 100 ml /min
Proximal：100% Occlusion Distal：0 Pa
( )∫ ⋅−⋅=T outoutininloss dtQPQPE
7.80 mm2
1.6 mm2
Energy loss
489.8 μW
Velocity (m/s)
489.8
93.1 111.7 63.2
0
100
200
300
400
500
600
1st 2nd 1st 2nd
Energy loss uW
Energy loss
Auto suture
Hand suture
CFD Analysis for Automated Distal Anastomosis in Coronary Bypass Grafting: Need of In-vitro Training with Quantitative anastomotic Quality Assessment
Young-Kwang Park, PhD1, Tadashi Motomura, MD, PhD2, Daisuke Ogawa1, Naohiko Kanemitsu, MS1, Gustavo Guajardo Salinas, MD2, Basel Ramlawi, MD, MMSc2, Mitsuo Umezu, PhD1, Mahesh Ramchandani, MD2 1: TWIns, Waseda University, Tokyo, Japan
2: Cardiovascular Surgery & Thoracic Transplant, The Methodist Hospital Debakey Heart & Vascular Center, Houston, TX, United States, 77030
International Society for Minimally Invasive Cardiothoracic Surgery, Annual Scientific Meeting 2013 in Czech Republic!
Abstract!Objective: Proximal automated suture devices are clinically used for off-pump coronary bypass grafting (OPCAB). Beyond standard OPCAB methods, an even less invasive approach has been applied, so-called “minimally invasive coronary artery bypass (MICS-CAB).” Due to the small surgical field in MICS-CAB, distal anastomoses in the circumflex or right coronary artery territory are technically challenging. Distal coronary automated anastomosis devices are clinically available and offer a promising option for the MICS-CAB operation. However, in vitro imaging analysis and the need for device deployment training are not well investigated. This study aims to assess morphological and hemodynamic characteristics of automated distal coronary artery anastomotic device compared with hand-sewn anastomoses using rapid computational fluid dynamics (CFD) analysis and multiple quantitative analyses. Materials and Methods: A tissue-mimicking silicone-rubber coronary model was used by a cardiac surgeon to create 2 hand-sewn models and 2 automated suture models each. For morphological assessment, minimum cross-sectional area (CSA) was measured by Micro CT scan with a special 50 µm resolution. Energy loss value was calculated using CFD techniques to assess the degree of anastomotic stenosis (where high energy loss represents high stenosis). These parameters were compared for the first and second automated suture models. Results: Inadequate installation of automated device encompassed poor anastomosis with high energy loss (489.8 µW) and a narrowed anastomosis (1.64 mm2), as opposed to hand suture group (mean energy loss of 87.5 µW and mean CAS of 9.4 mm2). In contrast, properly installed graft to the automated device significantly improved energy loss (93.1 µW, 81% improvement) and a CSA (7.80 mm2, 475% improvement). This result was comparable with hand sewn group and suggested importance of graft installation training as well as final deployment techniques. Conclusions: Automated suturing of distal anastomoses showed equivalent anastomotic qualities compared with conventional hand suture anastomosis. As well as hand sewing skills, it is equally important to maintain consistent anastomosis quality for automated device. Particularly, graft installation and automated clip deployment maneuvering may require systematic in-vitro training and imaging/quantitative assessment prior to device clinical implementation.
Introduction!
Conclusions!
Methods! Results!
Beating heart simulator
Fat tissue
Graft vessel
Coronary artery
Coronary artery model
Auto suture n=2 Hand suture n=2
1mm
14.4 mm2
1mm
4.5 mm2
1mm
7.8mm2
1mm
93.1 μW 111.7 μW 63.2 μW
Cross!Sectional!Area
Auto suture Hand suture
Micro focus CT scanner
Scan 3D Rendering Mesh CFD Analysis
Automated suturing of distal anastomoses showed equivalent anastomotic qualities compared with conventional hand suture anastomosis. As well as hand sewing skills, it is equally important to maintain consistent anastomosis quality for automated device. Particularly, graft installation and automated clip deployment maneuvering may require systematic in-vitro training and imaging/quantitative assessment prior to device clinical implementation.
This study aims to assess morphological and hemodynamic characteristics of automated d i s t a l c o r o n a r y a r t e r y anastomotic device compared with hand-sewn anastomoses using rapid computational fluid dynamics (CFD) analysis and multiple quantitative analyses.
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