A Novel Use of a Tissue Oxygenation Monitor at Time of Uterus Transplantation and Hysterectomy – A Feasibility Study

While thrombosis is the most common indication for graft failure and immediate hysterectomy of a transplanted uterus, there is no optimal method to monitor graft perfusion. In this feasibility study, a near-infrared spectroscopy probe that monitors local tissue oxygenation (StO 2 ) was attached to four uterine cervices and three donor cervices at the time of hysterectomy and transplantation respectively. Real-time StO 2 measurements were gathered at key surgical steps of the hysterectomies and uterus transplantations. The average StO 2 for the sequential steps of a hysterectomy of baseline, ovarian vessel ligation, contralateral ovarian vessel ligation, uterine vessel ligation, contralateral uterine vessel ligation, and colpotomy was 70.2%, 56.7%, 62.1%, 50.5%, 35.8%, and 8.5% respectively. The average StO 2 for the sequential steps of uterus transplantation of iliac vein anastomosis, iliac artery anastomosis, contralateral iliac vein anastomosis, contralateral iliac artery anastomosis, and vaginal anastomosis was 8.9%, 27.9%, 56.9%, 65.9%, and 65.2% respectively. As uterine blood supply decreases in a hysterectomy, the measured StO 2 also decreases, and vice versa for uterus transplantation. Tissue oximetry may be a reliable, non-invasive means of monitoring perfusion of a uterine graft. Additional studies are needed to determine if these devices complement current assessments of uterine graft viability and salvage thrombosed grafts.