Atherosclerosis Alters Loading-Induced Arterial Damage: Implications for Robotic Surgery

Abstract

BackgroundLack of intra-operative haptic information during robotic surgery increases the risk for unintended tissue overload and damage. Knowledge about the acute and chronic fundamental relationship between force load and induced damage in healthy and diseased arteries is crucial to enable intra-operative haptic feedback or shared autonomy and improve patient safety.MethodsArteries of wildtype and atherosclerotic mice were clamped in vivo for 2 minutes (0.0N, 0.6N or 1.27N). Histological analysis (Verhoeff’s-Van Gieson, Osteopontin, CD45, CD105) was performed immediately, or after 6 hours, 2 weeks or 1 month. Endothelium-dependent and–independent vasodilatation was assessed immediately or 1 month after clamping.ResultsEndothelium dependent vasodilatation is worse after clamping of wildtype arteries, but is restored after one month. Clamping also results in flattening of the innermost elastic membrane of both genotypes, which is reversed over time for wildtype arteries but not for vessels from atherosclerotic mice. Higher osteopontin content in wildtype and LDLR-/- mice after 2 weeks suggests a phenotypic switch of the medial smooth muscle cells (SMCs), an effect that is reversed after 1 month. While inflammation in the intima diminishes, medial CD45 content rises through time in both genotypes. CD105 staining shows that even manipulation without clamping results in endothelial cell loss in both LDLR+/+ and LDLR-/- mice.ConclusionsArterial clamping induces different acute and long-term injury to the vessel wall of atherosclerotic and healthy arteries.

A Chemomechanobiological Model of the Long-Term Healing Response of Arterial Tissue to a Clamping Injury

“…In total, all mice that underwent surgery were divided into eighteen groups corresponding to a particular condition, depending on the clamping force and the healing time, and on the type of assessment, i.e., histology or myograph. More details on these animal experiments are given in Geenens et al ( 2016a ).…”

“…The material, damage and remodeling models explained above are used for an in silico reproduction of the experiments carried out by Geenens et al ( 2016a ). A finite element model is set up in Abaqus/Standard 2017 to represent a mouse aorta.…”

“…For example, endothelial denudation is a widely known effect of clamping (Slayback et al, 1976 ; Barone et al, 1989 ; Margovsky et al, 1997 , 1999 ; Hangler et al, 2008 ; Vural et al, 2008 ; Famaey et al, 2010 ; Geenens et al, 2016a , b ). Several studies also report damage to the extracellular matrix (ECM) in the media with flattened elastic lamellae (Barone et al, 1989 ; Margovsky et al, 1999 ; Famaey et al, 2010 ; Geenens et al, 2016a ). Moreover, healing after arterial clamping usually implies some degree of inflammation and subsequent tissue remodeling (Geenens et al, 2016a ).…”

“…Several studies also report damage to the extracellular matrix (ECM) in the media with flattened elastic lamellae (Barone et al, 1989 ; Margovsky et al, 1999 ; Famaey et al, 2010 ; Geenens et al, 2016a ). Moreover, healing after arterial clamping usually implies some degree of inflammation and subsequent tissue remodeling (Geenens et al, 2016a ).…”

“…The tonicity of vascular smooth muscle cells (SMC) after clamping was also studied extensively (Barone et al, 1989 ; Famaey et al, 2010 ; Geenens et al, 2016b ). Experimental data on the effects of arterial clamping were collected in mice (Geenens et al, 2016a , b ). In this study, descending thoracic aortas were clamped at different levels of loading.…”