RESUMO
Soft tissue defects involving the distal lower extremity present challenging problems for orthopaedic surgeons to manage. Historically, wounds not amenable to primary closure have necessitated assistance from multidisciplinary teams using plastic surgeons to obtain adequate soft tissue coverage through rotational flap or free tissue transfer procedures. Techniques related to soft tissue rearrangement and local rotational flap coverage have advanced over the years with a growing knowledge of local anatomy and vasculature. The reverse sural flap may be performed to cover soft tissue defects within 10 cm of the foot or ankle region, negating the need for microvascular intervention. The simplistic nature of the reverse sural flap is appealing to orthopaedic surgeons as a means to provide timely patient care without additional support because it does not require microvasculature work or the need for intraoperative microscopes and has been popularized among orthopaedic trauma surgeons as a necessary tool to possess. Here, we discuss the reverse sural flap to include history, relevant anatomy, clinical indications, and a description of the technique for application.
RESUMO
Thrombosis in post-transcatheter aortic valve replacement (TAVR) patients has been correlated with flow stasis in the neo-sinus. This study investigated the effect of the post-TAVR geometry on flow stasis. Computed tomography angiography of 155 patients who underwent TAVR using a SAPIEN 3 were used to identify patients with and without thrombosis, and quantify thrombus volumes. Six patients with 23-mm SAPIEN 3 valves were then selected from the cohort and used to create patient-specific post-TAVR computational fluid dynamic models. Regions of flow stasis (%Volstasis, velocities below 0.05 m/s) were identified. The results showed that all post-TAVR anatomical measurements were significantly different in patients with and without thrombus, but only sinus diameter had a linear correlation with thrombus volume (r = 0.471, p = 0.008). A linear correlation was observed between %Volstasis and thrombus volume (r = 0.821, p = 0.007). The combination of anatomy and valve deployment created a unique geometry in each patient, which when combined with patient-specific cardiac output, resulted in distinct flow patterns. While parametric studies have shown individual anatomical or deployment metrics may relate to flow stasis, the combined effects of these metrics potentially contributes to the biomechanical environment promoting thrombosis, therefore hemodynamic studies of TAVR should account for these patient-specific factors.
