Abstract Observing graft blood supply post kidney trans- plantation is essential. Compromised graft perfusion must be identified without delay to preserve organ survival. Implantable probes have revolutionised the graft monitoring process in kidney transplantation leading to safe, continuous, and distinct monitoring of blood supply. The Implantable Cook-Swartz Doppler Flow Monitoring System allows immediate salvaging of a compressed kidney. The implantable Doppler probe can easily and effectively identify such cases and save the limited number of organs that are available to today’s patients. Introduction Observing graft blood supply after a kidney transplant is essential. Compromised graft perfusion must be identified without delay to preserve organ survival. With today’s increasing demand for kidneys, postoperative surveillance must evolve to prolong transplant success. Traditional methods (eg, Doppler ultrasound) can be slow and ambiguous. They also must be performed repetitively after kidney transplantation. Implantable probes have revolutionized graft monitoring during kidney transplantation, leading to safe, continuous, and distinct monitoring of vascular anastomoses. By adopting this technique (eg, initially introduced to observe microvascular tissue transplants, 1 free flaps, 2 and pediatric liver transplants 3 ), surgeons have become more effective at monitoring postoperative grafts. Our team has used the probe quickly and effectively to monitor blood flow to the kidney. This technique provides immediate indication of blood flow and, should it be required, allows the surgeon to readjust the position of the kidney to maximize flow before incision closure, reducing the need for postoperative exploration. By adopting this method, we can be assured that the kidney is perfused, and we eliminate the need for ultrasound monitoring. 7 days after surgery the probes are removed. Removal is simple, and is done by gentle traction on the wire (1/10th lb approximately, 50 g pressure) that disengages the crystal from the cuff. Implantation of the probe on the renal artery during transplant can ensure blood flow to the kidney. Venous return can also be monitored using the probe; however, it is costlier. Similarly, multiple probes may be inserted should there be multiple anastomoses; but again, this would increase cost. We use the Implantable Cook-Swartz Doppler Probe (Cook Vascular Inc, Vandergrift, PA, USA) (Figure 1). 4 CASe RePORT Rescue of Transplanted Kidney Thanks to an Implantable Doppler Probe: Is This the Future? David N. Hakim, 1 Maria Abou Nader, 2 Anshuman Sood, 3 Apostolos Kandilis, 4 Nadey S. Hakim 4 Copyright © Başkent University 2016 Printed in Turkey. All Rights Reserved. From the 1 Imperial College London, United Kingdom; 2 the American University of Beirut, Lebanon; 3 the Royal College of Surgeons, Ireland; and the 4 Imperial College Healthcare NHS Trust Acknowledgements: The authors declare that they have no sources of funding for this study, and they have no conflicts of interest to declare. Corresponding author: Professor Nadey S. Hakim, Imperial College Healthcare NHS Trust, Ducane Road, London, United Kingdom Phone: +44 78 5050 3297 E-mail: nadey@globalnet.co.uk Experimental and Clinical Transplantation (2016) 4: 454-455 DOI: 10.6002/ect.2014.0135 Figure 1. The Cook-Swartz Doppler Probe: 20-MHz crystal attached to a cuff, allowing for easy attachment, and safe, continuous monitoring of microvascular anastomoses