Optimizing Individual Wound Closure Practice Using Augmented Reality: A Randomized Controlled Study.

Background Suturing requires repeated practice with guidance to prevent skill deterioration; however, guidance is often limited by expert availability. There is evidence that augmented reality (AR) may assist procedural skill acquisition among learners. This study examines the use of an AR suture guidance application to assist the independent practice of suturing. Methodology A novel suture guidance application was designed for the Microsoft HoloLens. The guidance system included a calibration system and holograms that projected over a suture pad in a stepwise manner. To assess the application, 30 medical students were recruited and randomly assigned to two groups. The control group (n = 16) was given 30 minutes of independent suture practice, while the experimental group (n = 14) utilized the suture guidance application. Both groups completed a pre- and post-test wound closure assessment. After the post-test, the control group trialed the suture guidance application. All participants completed a feedback survey on the application. Statistical analysis was completed using Stata (StataCorp., College Station, TX, USA) with paired Student's t-tests and Welch's t-tests with a significance of 95%. Results Both groups demonstrated a significant improvement in total time and time per stitch during the post-test. Additionally, comparing pre- and post-test assessments in the experimental group revealed a significant improvement in the total number of stitches (p = 0.007), the ratio of bisecting stitches (p = 0.02), and the symmetry of stitch bite (p = 0.03). The feedback survey supported the application for guiding suture placement and spacing. Participants identified limitations in the hologram stability and neck positioning. Conclusions This study suggests the potential to use AR to facilitate the independent practice of wound closure within simulation environments.

Proteinase-activated receptor-2 antagonist C391 inhibits Alternaria-induced airway epithelial signalling and asthma indicators in acute exposure mouse models.

BACKGROUND AND PURPOSE: Despite the availability of a variety of treatment options, many asthma patients have poorly controlled disease with frequent exacerbations. Proteinase-activated receptor-2 (PAR2) has been identified in preclinical animal models as important to asthma initiation and progression following allergen exposure. Proteinase activation of PAR2 raises intracellular Ca2+ , inducing MAPK and ß-arrestin signalling in the airway, leading to inflammatory and protective effects. We have developed C391, a potent PAR2 antagonist effective in blocking peptidomimetic- and trypsin-induced PAR2 signalling in vitro as well as reducing inflammatory PAR2-associated pain in vivo. We hypothesized that PAR2 antagonism by C391 would attenuate allergen-induced acutely expressed asthma indicators in murine models. EXPERIMENTAL APPROACH: We evaluated the ability of C391 to alter Alternaria alternata-induced PAR2 signalling pathways in vitro using a human airway epithelial cell line that naturally expresses PAR2 (16HBE14o-) and a transfected embryonic cell line (HEK 293). We next evaluated the ability for C391 to reduce A. alternata-induced acutely expressed asthma indicators in vivo in two murine strains. KEY RESULTS: C391 blocked A. alternata-induced, PAR2-dependent Ca2+ and MAPK signalling in 16HBE14o- cells, as well as ß-arrestin recruitment in HEK 293 cells. C391 effectively attenuated A. alternata-induced inflammation, mucus production, mucus cell hyperplasia and airway hyperresponsiveness in acute allergen-challenged murine models. CONCLUSIONS AND IMPLICATIONS: To our best knowledge, this is the first demonstration of pharmacological intervention of PAR2 to reduce allergen-induced asthma indicators in vivo. These data support further development of PAR2 antagonists as potential first-in-class allergic asthma drugs.

Practicing on the Advanced Training in Laparoscopic Suturing Curriculum (ATLAS): Is Mastery Learning in Residency Feasible to Achieve Expert-Level Performance in Laparoscopic Suturing?

BACKGROUND: Mastery learning assumes that given enough time and appropriate instructional strategies, most trainees will be able to achieve proficiency. Expert-level performance requires numerous hours of intensive and focus practice. We aimed to study whether it was possible for surgical trainees to achieve expert-derived proficiency level in laparoscopic suturing using the Advanced Training in Laparoscopic Suturing (ATLAS) curriculum over a short period of time. STUDY DESIGN: A multicenter IRB approved prospective study included surgery residents and minimally invasive fellows. Participants underwent weekly supervised instruction and assessments of ATLAS skills and self-directed practice between sessions over 12 weeks. Participants were asked to practice until they achieved previously established proficiency benchmarks of expert laparoscopic surgeons. RESULTS: Fifteen participants, PGY2 to PGY6, from 3 institutions practiced on the ATLAS curriculum. Three participants were able to achieve proficiency on the entire curriculum, with a cumulative practice time varying between 3.4 and 7.6 hours. Individual tasks had varying degrees of difficulty ranging from 85% proficiency on task 1 to 33.3% proficiency for task 6. Using a mixed-method model, the mean cumulative hours of practice to reach the benchmark threshold was estimated for each task and varied from 4.5 to 13.2 hours. The improved performance was associated with higher PGY level and proficiency in FLS. CONCLUSIONS: This study demonstrates that it is possible for some senior surgical trainees to achieve proficiency in an expert-level laparoscopic suturing curriculum. This study establishes a learning curve for each ATLAS individual task. Some learners may not be able to achieve proficiency on the entire curriculum over a short period of practice. Additional studies are needed to assess how to shorten the learning curve with effective instructional methods such as expert-guided training with immediate feedback.