Dear Authors I read with special interest the article by Dr. Shockley et al(1). I noticed that some previous studies performed in humans were omitted. They have essential information about the uterine blood supply, a fact that would make it unlikely to prove his hypothesis. Human uterine blood supply has two main anastomotic pedicles, the upper and the lower one. The upper pedicle is classically well-known and formed by the ovary and the round ligament artery; the lower one, less known, is formed by the colpo-uterine vessels wich arises from the vaginal arteries (2). In terms of collateral blood supply, the lower pedicle is the most important suppletory way to preserve uterine vitality after uterine artery ligature or embolization. In vivo experiences have demonstrated that a simultaneous and bilateral ligature of uterine and ovary arteries has no consequence for uterine vitality (3), this is because the lower anastomotic pedicle (colpo-uterine anastomotic component) is open. Anatomical images of the lower pedicle allow to understand how big it is. Arterial connections within the vaginal and uterine systems are continuously open, which guarantees uterine vitality after bilateral uterine occlusion. The use of a device named FlostatTM, which occludes both uterine arteries and the vaginal anastomotic component (4), can only be used by 6 hs, because the upper pedicles (ovarian and round ligament artery) are unable to maintain uterine vitality. On the contrary, when both uterine and ovary arteries are occluded by clamps, a sample of arterial blood taken from the middle part of the uterine artery has almost identical oxygen partial pressure than a comparative sample taken from the radial artery. Taking into account that this study was performed to be applied in humans, it is remarkable that an update of the uterine blood supply was omitted. Prof. Dr. José Palacios-Jaraquemada School of Medicine, University of Buenos Aires, Argentina 1.- Shockley M, Arnolds K, Beran B, Rivas K, Escobar P, Tzakis A, Falcone T, Sprague ML, Zimberg S. Uterine viability in the baboon after ligation of uterine vasculature: a pilot study to assess alternative perfusion and venous return for uterine transplantation. Fertil Steril. 2017 Apr;107(4):1078-1082 2.- Palacios Jaraquemada JM, García Mónaco R, Barbosa NE, Ferle L, Iriarte H, Conesa HA. Lower uterine blood supply: extrauterine anastomotic system and its application in surgical devascularization techniques. Acta Obstet Gynecol Scand. 2007;86(2):228-34. 3.-Gezginç K, Yazici F, Koyuncu T, Mahmoud AS. Bilateral uterine and ovarian artery ligation in addition to B-lynch suture may be an alternative to hysterectomy for uterine atonic hemorrhage. Clin Exp Obstet Gynecol. 2012;39(2):168-70. 4.- Vilos GA, Vilos EC, Romano W, Abu-Rafea B. Temporary uterine artery occlusion for treatment of menorrhagia and uterine fibroids using an incisionless Doppler-guided transvaginal clamp: case report. Hum Reprod. 2006 Jan;21(1):269-71