1 Lindsay E. Janes, BS Helen G. Hui-Chou, MD Jamil A. Matthews, MD, MS Jennifer Sabino, MD Devinder P. Singh, MD Division of Plastic Surgery University of Maryland Medical Center Baltimore, Md. Sir: I angiography, a technique recently used to assess blood supply in free flaps, has been used in breast reconstruction to assist in evaluation of arterial perfusion and ischemic debridement.1,2 We present a technique to extend the use of this technology to assess venous outflow, the predominant form of flap failure,3–5 taking advantage of the 2 properties of ICG dye: its short 2to 3-minute halflife and tight binding to plasma proteins which keeps it intravascular. The patient was a 56-year-old woman who presented with a history of invasive ductal carcinoma of the right breast and subsequently underwent modified radical mastectomy and reconstruction with free flap. ICG angiography (SPY Intraoperative Imaging Systems; Novadaq Technologies Inc., Mississauga, ON, Canada) was used to assess both immediate and delayed venous outflow of the free flap before division from the external iliac vein and after reanastomosis with the internal mammillary vein. For immediate assessment, image acquisition occurred from the time of injection of the 2.5 mg/ml ICG dye solution until 5 minutes post injection with the artery and vein in clear view. For delayed assessment, the laser-assisted fluorescence imaging was used to analyze the flap fluorescence 25 minutes after injection of the dye. Venous outflow of the skin flap imaged before division and after anastomosis of vessels revealed similar patterns in both immediate and delayed venous assessment. Evaluation of the free flap after elevation but before division from the external iliac vein using the delayed technique revealed that the deep venous system was sufficient to drain the entire flap. After anastomosis of vessels with the recipient site, imaging using the immediate technique revealed visualization of the arterial inflow followed by illumination of the tissue flap indicating arterial sufficiency Copyright © 2014 The Authors. Published by Lippincott Williams & Wilkins on behalf of The American Society of Plastic Surgeons. PRS Global Open is a publication of the American Society of Plastic Surgeons. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. Plast Reconstr Surg Glob Open 2014;2:e100; doi:10.1097/ GOX.0000000000000050; Published online 28 January 2014 Utilization of Near-infrared Indocyanine Green Angiography for Immediate and Delayed Venous Outflow Assessment in Breast Reconstruction: A Case Report