Vincent Sier, MSc

Throughout his Bachelor’s degree in Medicine, Vincent Sier discovered the intriguing world of preclinical vascular research at the group of dr. de Vries and prof. Quax. During these years, he focused on the application of ultrasound imaging (Vevo 3100) for murine vein graft and arteriovenous fistula models, while performing morphometrical, velocity-pertaining, and stiffness analyses. His interests are primarily targeted on shedding a light on vascular remodeling, in both a figurative and literal sense. Currently, after finishing his Master’s degree in Biomedical Sciences, he is continuing his research on vascular remodeling within the Leiden University Medical Center MD-PhD program.

Most recent publications

Preclinical evaluation of EpCAM-binding designed ankyrin repeat proteins (DARPins) as targeting moieties for bimodal near-infrared fluorescence and photoacoustic imaging of cancer
Houvast RD, Badr N, March T, de Muynck LDAN, Sier VQ, Schomann T, Bhairosingh S, Baart VM, Peeters JAHM, van Westen GJP, Plückthun A, Burggraaf J, Kuppen PJK, Vahrmeijer AL and Sier CFM
Fluorescence-guided surgery (FGS) can play a key role in improving radical resection rates by assisting surgeons to gain adequate visualization of malignant tissue intraoperatively. Designed ankyrin repeat proteins (DARPins) possess optimal pharmacokinetic and other properties for in vivo imaging. This study aims to evaluate the preclinical potential of epithelial cell adhesion molecule (EpCAM)-binding DARPins as targeting moieties for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of cancer.
Future surgeon: bridging the intergenerational gap
Huizing F, Sier VQ, Tresfon JAS, van der Vorst JR, Liem RSL, Schmitz RF, Schepers A, Houwert RM, Vriens MR, Snijders HS and Blok JJ
Exploring the surgical personality
Sier VQ, Schmitz RF, Schepers A and van der Vorst JR
Surgery is a demanding field, requiring determination and emotional stability. This review explores the surgical personality, addressing international personality differences between surgical and non-surgical specialties. Across the globe, surgically-interested individuals (i.e., medical students, residents, surgeons) generally scored higher on conscientiousness, open mindedness, and extraversion, and lower on neuroticism compared to non-surgically-interested contemporaries. Extraversion was inversely correlated to burnout in surgical residents and open mindedness to reduced competence in giving feedback. Although additional region- and/or country-specific research is warranted, being or becoming a surgeon appears to correlate to personality traits such as high conscientiousness and low neuroticism.
The big five: Studying the surgical personality
Sier VQ, Schmitz RF, Putter H, Schepers A and van der Vorst JR
The challenging nature of performing surgery on a personal and professional level demands specific characteristics. Personality traits play an important role in the nature and behavior of humans, which are studied using the five-factor model. Therefore, we investigated the personality of 3 surgical generations.
Visualization of Murine Vascular Remodeling and Blood Flow Dynamics by Ultra-High-Frequency Ultrasound Imaging
Sier VQ, de Jong A, Quax PHA and de Vries MR
Vein grafts (VGs) are used to bypass atherosclerotic obstructions and arteriovenous fistulas (AVFs) as vascular access for hemodialysis. Vascular remodeling governs post-interventional arterialization, but may also induce VG and AVF failure. Although the endpoint characteristics of vascular remodeling are known, the in vivo process and the role of blood flow dynamics has not been fully studied. Therefore, here we non-invasively quantify vascular remodeling and blood flow alterations over time in murine VG and AVF models. C57BL/6J ( = 7, chow diet) and atherosclerosis-prone ApoE3*Leiden ( = 7) mice underwent VG surgery. Ultrasound imaging was performed at 3, 7, 14, 21, and 28 days post-surgery. C57BL/6J mice ( = 8) received AVF surgery. Ultrasound imaging was performed at 7 and 14 days post-surgery. The luminal volume increased by 42% in the VGs of C57BL/6J and 38% in the VGs of ApoE3*Leiden mice at 28 days relative to 3 days post-surgery. Longitudinally, an 82% increase in wall volume and 76% increase in outward remodeling was found in the ApoE3*Leiden mice, with a constant wall size in C57BL/6J mice. Proximally, the pulsatility index, resistive index, and peak systolic velocity decreased longitudinally in both groups. Distally, the maximum acceleration increased with 56% in C57BL/6J VGs. Among the AVFs, 50% showed maturation after 7 days, based on a novel flow-criterium of 23 mL/min. Distinct flow patterns were observed at the anastomotic site and inflow artery of the AVFs relative to the control carotid arteries. Vascular remodeling can be quantified by ultra-high-frequency ultrasound imaging over time in complex animal models, via three-dimensional structural parameters and site-specific hemodynamic indices.