Simulation for Colorectal Surgery.

Introduction: Colorectal surgery is a highly specialized field in surgery that deals with the surgical intervention of disease processes of the colon, rectum, and anus. Gaining proficiency in this field requires training both inside and outside of the operating room. Simulation plays a key role in training surgeons in colorectal surgery. The goal of this study is to review the currently available simulators for training in the field of colorectal surgery. Methods: A review of the literature was conducted to identify simulators that are both physical such as benchtop, live animal, and cadaver, as wells as virtual reality (VR) simulators. Any reported validity evidence for these simulators were also presented. Results: There are several benchtop physical models made of silicone for training in basic colorectal tasks, such as hand-sewn and stapled anastomosis. To improve realism, explanted animal and cadaveric specimens were also used for training. To improve repeatability, objective assessment, both commercial and VR simulators also exist for training in both open and laparoscopic colorectal surgery and emerging areas such as endoscopic submucosal dissection. Conclusion: Simulation-based training in colorectal surgery is here to stay and is going to play a significant role in training, credentialing, and quality improvements.

Pediatric in vitro and in silico models of deposition via oral and nasal inhalation.

Respiratory tract deposition models provide a useful method for optimizing the design and administration of inhaled pharmaceutical aerosols, and can be useful for estimating exposure risks to inhaled particulate matter. As aerosol must first pass through the extrathoracic region prior to reaching the lungs, deposition in this region plays an important role in both cases. Compared to adults, much less extrathoracic deposition data are available with pediatric subjects. Recently, progress in magnetic resonance imaging and computed tomography scans to develop pediatric extrathoracic airway replicas has facilitated addressing this issue. Indeed, the use of realistic replicas for benchtop inhaler testing is now relatively common during the development and in vitro evaluation of pediatric respiratory drug delivery devices. Recently, in vitro empirical modeling studies using a moderate number of these realistic replicas have related airway geometry, particle size, fluid properties, and flow rate to extrathoracic deposition. Idealized geometries provide a standardized platform for inhaler testing and exposure risk assessment and have been designed to mimic average in vitro deposition in infants and children by replicating representative average geometrical dimensions. In silico mathematical models have used morphometric data and aerosol physics to illustrate the relative importance of different deposition mechanisms on respiratory tract deposition. Computational fluid dynamics simulations allow for the quantification of local deposition patterns and an in-depth examination of aerosol behavior in the respiratory tract. Recent studies have used both in vitro and in silico deposition measurements in realistic pediatric airway geometries to some success. This article reviews the current understanding of pediatric in vitro and in silico deposition modeling via oral and nasal inhalation.