Influence of Slippery Pacemaker Leads on Lead-Induced Venous Occlusion Introduction Does lead size matter? Maybe. Small-diameter lead: increased rate of lead failure Simulations show flow stasis is concentrated around leads. What if slippery? Pitcher plant inspired omniphobic surface coating (SLIPS) Computational Approach r · u =0 u k = λn · σ · (I - nn)/μ @⌧ @ t + u · r⌧ -r · r⌧ = H ⇢ ✓ @ u @ t + u · ru ◆ = r · σ where σ = −pI + μ(∇u + ∇(u) T ). Slip boundary conditions: Validation Eccentric Cylinders h h =0.55, 0.41 and 0.26 cm. Patient-specific Simulation A B Q = 16cc/s, R o =0.55cm, R i =0.117cm λ/R 0 = 10 λ/R 0 =1 λ/R 0 =0.1 λ/R 0 =0 V [cm/s] S. Bhatia, D. Obenauf, O. S. Pak Department of Mechanical Engineering Santa Clara University W. Yang, M. Esmaily-Moghadam, J. Feinstein Department of Pediatric Cardiology and Mechanical Engineering Stanford University Pacemakers are used to treat arrhythmias. Pacemaker implantation: between 1993-2009 Pacemaker implantation: Complications: Infection, between 1993-2009, 2.9 M patients in US Venous occlusion: Symptomatic: 15-30% for adults and 20% for children 1-3% Implemented in Simvascular package Slip boundary conditions: Navier-Stokes equations: Residence time: et al.,Phys Fluid Simulation setting: λ/R 0 =0 λ/R 0 =0.2 λ/R 0 =1 No-slip Slippery The influence of a slippery hydrodynamic condition on pacemaker lead surface is evaluated in idealized and patient-specific scenarios. The slippery surface condition reduces the residence time in close proximity of the lead, suggesting its possibility of mitigating risks of lead-induced thrombosis. References: Leslie et al., Nature Biotechnology, 2014 1. National Heart, Lung, and Blood Institute, NIH 2 Leslie et al. (2014).Nature Biotechnol. 32,1134-1140. Image: NHLB, NIH Leslie et al. (2014).Nature Biotechnol. [cm/s]
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Influence of Slippery Pacemaker Leads on Eccentric lead ...€¦ · Influence of Slippery Pacemaker Leads on Lead-Induced Venous Occlusion Introduction Introduction! Pacemakers are
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Influence of Slippery Pacemaker Leads on Lead-Induced Venous Occlusion
Introduction
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
http://www.nhlbi.nih.gov
Stanford University Introduction 2 / 9
Introduction
! Does lead size matter? Maybe.
! Small-diameter lead: increased rate of lead failure
! Simulations show flow stasis is concentrated around leads.! What if slippery?
! Implemented in Simvascular package! Stabilized finite element formulation (SUPG),! Linear finite element for space discretization! Generalized α method for time integration
Stanford University Methods 4 / 9
Validation
Eccentric Cylinders
Eccentric lead
! Three positions are simulated: h = 0.55, 0.41 and 0.26 cm.
! Slippery coating reduces flow stasis between lead and vessel wall.
h
Stanford University Results 7 / 9
Eccentric lead
! Three positions are simulated: h = 0.55, 0.41 and 0.26 cm.
! Slippery coating reduces flow stasis between lead and vessel wall.
h
Stanford University Results 7 / 9
Eccentric lead
! Three positions are simulated: h = 0.55, 0.41 and 0.26 cm.
! Slippery coating reduces flow stasis between lead and vessel wall.
h
Stanford University Results 7 / 9
Eccentric lead
! Three positions are simulated: h = 0.55, 0.41 and 0.26 cm.
! Slippery coating reduces flow stasis between lead and vessel wall.
h
Stanford University Results 7 / 9
Eccentric lead
! Three positions are simulated: h = 0.55, 0.41 and 0.26 cm.
! Slippery coating reduces flow stasis between lead and vessel wall.
h
Stanford University Results 7 / 9
Patient-specific Simulation
Conclusions �
�
Leslie et al., Nature Biotechnology, 2014
1. Slippery surfaces 2. Lead-induced occulsions
3. Simulation and comparison 4. Patient specific modeling
Stanford University Conclusions 9 / 9
Conclusions �
�
Leslie et al., Nature Biotechnology, 2014
1. Slippery surfaces 2. Lead-induced occulsions
3. Simulation and comparison 4. Patient specific modeling
Stanford University Conclusions 9 / 9
Anatomy realistic cases
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
AB
C
noslip slip
noslip slipnoslip slip
Vel
RT
Vel
RT
Vel
RT
Stanford University Results 8 / 9
Anatomy realistic cases
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
AB
C
noslip slip
noslip slipnoslip slip
Vel
RT
Vel
RT
Vel
RT
Stanford University Results 8 / 9
Anatomy realistic cases
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
S. Bhatia, D. Obenauf, O. S. Pak Department of Mechanical Engineering
Santa Clara University
W. Yang, M. Esmaily-Moghadam, J. Feinstein Department of Pediatric Cardiology and Mechanical Engineering
Stanford University
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
http://www.nhlbi.nih.gov
Stanford University Introduction 2 / 9
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
http://www.nhlbi.nih.gov
Stanford University Introduction 2 / 9
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
http://www.nhlbi.nih.gov
Stanford University Introduction 2 / 9
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
http://www.nhlbi.nih.gov
Stanford University Introduction 2 / 9
Introduction
! Pacemakers are used to treat arrhythmias.! Pacemaker implantation: between 1993-2009, 2.9 M patients in US! Complications: Infection, haemothorax, lead dislodgement, lead
failure, venous occlusion...! Venous occlusion: 15-30% for adults and 20% for children
! Symptomatic: 1-3%! Challenges arise with system revision or upgrade.
! Implemented in Simvascular package! Stabilized finite element formulation (SUPG),! Linear finite element for space discretization! Generalized α method for time integration
! Implemented in Simvascular package! Stabilized finite element formulation (SUPG),! Linear finite element for space discretization! Generalized α method for time integration
! Implemented in Simvascular package! Stabilized finite element formulation (SUPG),! Linear finite element for space discretization! Generalized α method for time integration
Stanford University Methods 4 / 9
Anatomy realistic cases
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
AB
C
noslip slip
noslip slipnoslip slip
Vel
RT
Vel
RT
Vel
RT
Stanford University Results 8 / 9
Anatomy realistic cases
! A 3-4 year old patient (pulsatile inflow, resistance outlet)! Residence time: ∂τ
∂t + u · ∇τ − ∇ · κ∇τ = H (Esmaily Moghadamet al.,Phys Fluids, 2013)
AB
C
noslip slip
noslip slipnoslip slip
Vel
RT
Vel
RT
Vel
RT
Stanford University Results 8 / 9
The influence of a slippery hydrodynamic condition on pacemaker lead surface is evaluated in idealized and patient-specific scenarios.
The slippery surface condition reduces the residence time in close proximity of the lead, suggesting its possibility of mitigating risks of lead-induced thrombosis.
References:
Introduction
! Does lead size matter? Maybe.
! Small-diameter lead: increased rate of lead failure
! Simulations show flow stasis is concentrated around leads.! What if slippery?