Preoperative exercise training for adults undergoing elective major vascular surgery: A systematic review

Patients undergoing major vascular surgery may have an increased risk of postoperative complications due to poor ‘fitness for surgery’. Prehabilitation aims to optimise physical fitness and risk factors before surgery to improve outcomes. The role of exercise-based prehabilitation in vascular surgery is currently unclear. Therefore, the aim of this systematic review was to assess the benefits and harms of preoperative exercise training in adults undergoing elective vascular surgery. We searched MEDLINE, Embase, CINAHL, and CENTRAL databases, trial registries, and forward and backward citations for studies published between January 2008 and April 2021. We included randomised trials that compared patients receiving exercise training with those receiving usual care or no training before vascular surgery. Outcomes included mortality, complications, and health-related quality of life (HRQOL). Three trials with 197 participants were included. All studies involved people undergoing abdominal aortic aneurysm (AAA) repair. Low-certainty evidence could not differentiate between rates of all-cause mortality. Moderate-certainty evidence indicated that postoperative cardiac and renal complications were less likely to occur in people who participated in preoperative exercise training compared with those who did not. Low-certainty evidence also indicated better postoperative HRQOL outcomes in people who undertook prehabilitation. There were no serious exercise-related adverse events. The evidence on preoperative exercise training for AAA patients is promising, but currently insufficiently robust for this intervention to be recommended in clinical guidelines. High quality trials are needed to establish its clinical and cost-effectiveness. Research is also needed to determine the feasibility and effects of prehabilitation before lower-limb revascularisation

Preoperative exercise training for adults undergoing elective major vascular surgery: A systematic review

Patients undergoing major vascular surgery may have an increased risk of postoperative complications due to poor ‘fitness for surgery’. Prehabilitation aims to optimise physical fitness and risk factors before surgery to improve outcomes. The role of exercise-based prehabilitation in vascular surgery is currently unclear. Therefore, the aim of this systematic review was to assess the benefits and harms of preoperative exercise training in adults undergoing elective vascular surgery. We searched MEDLINE, Embase, CINAHL, and CENTRAL databases, trial registries, and forward and backward citations for studies published between January 2008 and April 2021. We included randomised trials that compared patients receiving exercise training with those receiving usual care or no training before vascular surgery. Outcomes included mortality, complications, and health-related quality of life (HRQOL). Three trials with 197 participants were included. All studies involved people undergoing abdominal aortic aneurysm (AAA) repair. Low-certainty evidence could not differentiate between rates of all-cause mortality. Moderate-certainty evidence indicated that postoperative cardiac and renal complications were less likely to occur in people who participated in preoperative exercise training compared with those who did not. Low-certainty evidence also indicated better postoperative HRQOL outcomes in people who undertook prehabilitation. There were no serious exercise-related adverse events. The evidence on preoperative exercise training for AAA patients is promising, but currently insufficiently robust for this intervention to be recommended in clinical guidelines. High-quality trials are needed to establish its clinical and cost-effectiveness. Research is also needed to determine the feasibility and effects of prehabilitation before lower-limb revascularisation

Numerical analysis of hydraulic jumps using OpenFOAM

[EN] The present paper deals with a hydraulic jump study, characterization and numerical modeling. Hydraulic jumps constitute a common phenomenon in the hydraulics of open channels that increases the shear stress on streambeds, so promoting their erosion. A three-dimensional computational fluid dynamics model is proposed to analyze hydraulic jumps in horizontal smooth rectangular prismatic open-air channels (i.e., the so-called classical hydraulic jump). Turbulence is modeled using three widely used Reynolds-averaged Navier Stokes (RANS) models, namely: Standard k ε, RNG k ε, and SST k ω. The coexistence of two fluids and the definition of an interface between them are treated using a volume method in Cartesian grids of several element sizes. An innovative way to deal with the outlet boundary condition that allows the size of the simulated domain to be reduced is presented. A case study is conducted for validation purposes (FR1 ∼ 6.10, Re1 ∼ 3.5·105): several variables of interest are computed (sequent depths, efficiency, roller length, free surface profile, etc.) and compared to previous studies, achieving accuracies above 98% in all cases. In the light of the results, the model can be applied to real-life cases of design of hydraulic structures.This research was conducted thanks to the funding provided by the VALi + D R&D Program of the Generalitat Valenciana (Spain). It would not have been possible without the contribution of Daniel Valero and Beatriz Nacher of the Hydraulics Laboratory of the School of Civil Engineering (Universitat Politecnica de Valencia).Bayón Barrachina, A.; López Jiménez, PA. (2015). Numerical analysis of hydraulic jumps using OpenFOAM. Journal of Hydroinformatics. 17(4):662-678. https://doi.org/10.2166/hydro.2015.041S66267817