Multiscale spatial mapping of cell populations across anatomical sites in healthy human skin and basal cell carcinoma

Our understanding of how human skin cells differ according to anatomical site and tumour formation is limited. To address this, we have created a multiscale spatial atlas of healthy skin and basal cell carcinoma (BCC), incorporating in vivo optical coherence tomography, single-cell RNA sequencing, spatial global transcriptional profiling, and in situ sequencing. Computational spatial deconvolution and projection revealed the localisation of distinct cell populations to specific tissue contexts. Although cell populations were conserved between healthy anatomical sites and in BCC, mesenchymal cell populations including fibroblasts and pericytes retained signatures of developmental origin. Spatial profiling and in silico lineage tracing support a hair follicle origin for BCC and demonstrate that cancer-associated fibroblasts are an expansion of a POSTN+ subpopulation associated with hair follicles in healthy skin. RGS5+ pericytes are also expanded in BCC suggesting a role in vascular remodelling. We propose that the identity of mesenchymal cell populations is regulated by signals emanating from adjacent structures and that these signals are repurposed to promote the expansion of skin cancer stroma. The resource we have created is publicly available in an interactive format for the research community.

A Systematic Review of Simulation-Based Training in Vascular Surgery

Introduction

Recent advancements in surgical technology, reduced working hours, and training opportunities exacerbated by the COVID-19 pandemic have led to an increase in simulation-based training. Furthermore, a rise in endovascular procedures has led to a requirement for high-fidelity simulators that offer comprehensive feedback. This review aims to identify vascular surgery simulation models and assess their validity and levels of effectiveness (LoE) for each model in order to successfully implement them into current training curricula.

Methods

PubMed and EMBASE were searched on January 1, 2021, for full-text English studies on vascular surgery simulators. Eligible articles were given validity ratings based on Messick’s modern concept of validity alongside an LoE score according to McGaghie’s translational outcomes.

Results

Overall 76 eligible articles validated 34 vascular surgery simulators and training courses for open and endovascular procedures. High validity ratings were achieved across studies for: content (35), response processes (12), the internal structure (5), relations to other variables (57), and consequences (2). Only seven studies achieved an LoE greater than 3/5. Overall, ANGIO Mentor was the most highly validated and effective simulator and was the only simulator to achieve an LoE of 5/5.

Conclusions

Simulation-based training in vascular surgery is a continuously developing field with exciting future prospects, demonstrated by the vast number of models and training courses. To effectively integrate simulation models into current vascular surgery curricula and assessments, there is a need for studies to look at trainee skill retention over a longer period of time. A more detailed discussion on cost-effectiveness is also needed.