Free tissue transfer is a commonly performed procedure, especially at tertiary care hospitals. In free tissue transfer, "spare tissue" from one area of the body (donor site) is re-implanted to an area that is need of reconstruction (defect site). When relocated, the "spare tissue" is given vitality and blood supply at its new location by microscopically sewing and connecting its feeding artery and vein to an artery and vein in or near the defect site. Hence, this operation is referred to as "microvascular free tissue transfer" or "free flap". Defect sites most commonly result from tumor or cancer removal and trauma related injuries. Free flaps are frequently used to reconstruct breast tissue after mastectomy, head and neck cancer resections, extremity injuries, and chronically infected wounds. The indications, utilization, and expertise in free flap surgery continue to grow, providing patients with enhanced outcomes of otherwise difficult cancers and wounds.

This is a single-blinded multi-institutional randomized controlled trial to evaluate the effectiveness of Arista hemostatic matrix powder (Arista® AH, C. R. Bard, Inc. Davol, Warwick, RI) in reducing drainage output in anterolateral thigh (ALT) free flap donor sites. Increased drainage from donor sites can lead to seroma formation with possible secondary infection, delayed hospital discharge, and additional home care needs for drain care. Arista is an inert plant based absorbable surgical hemostatic powder that can be easily applied to broad surgical fields to reduce bleeding and seroma rates. Therefore, its application to free flap donor sites may bear significant potential benefit. Specific Aim 1: The main hypothesis of the study is that the use of Arista in anterolateral thigh (ALT) free flap donor sites prior to closure will reduce postoperative drain outputs and time to drain removal compared to ALT donor sites closed without Arista. Specific Aim 2: This study will also evaluate the secondary hypotheses that Arista will reduce postoperative ALT donor site seromas and patient hospital length of stay.