Systematic review of intra‐operative duplex scanning during renal transplantation

Abstract Introduction A systematic review of the value of intra‐operative duplex scanning during renal transplantation was undertaken. Methods Studies assessing intra‐operative renal cortical flow in the arcuate vessels with outcomes of ultrasound directed interventions during the initial procedure, delayed graft function, post‐operative resistive indices, graft losses and early returns to theatre for graft hypoperfusion were reviewed. PROSPERO registration: (https: //www. crd. york. ac. uk/prospero/displayᵣecord. php? ID=CRD42020203873). Results Literature searching identified 2069 articles for screening, with 131 reviewed and 12 selected for analysis comprising 5 individual case reports, one case series of 11 patients and 6 non‐randomised controlled trials. Studies with similar methodologies were pooled because of the low number of studies and outcomes. Outcomes of interest were not reported for all patients. Intra‐operative interventions comprising graft repositioning in 18 (16%) and vascular revision in 2 (2%) were performed in 115 patients undergoing intra‐operative scans. There were no graft losses or returns to theatre for graft hypoperfusion (0 of 108 cases) compared to 7 of 71 (10%) without intraoperative scanning (P = 0. 003). Three of 8 (38%) patients with high intra‐operative resistive indices (RIs) were returned to theatre for hypoperfusion compared to 1 of 110 (1%) patients with normal resistive indices (P = <0. 001). Ten of 13 (77%) patients with high RIs had delayed graft function compared to 10 of 40 (25%) with normal RIs (P = 0. 001). Conclusion Despite the absence of randomised controlled trials, and heterogeneous small studies, adverse outcomes were reduced with intra‐operative scanning. High intraoperative RIs were predictive of both delayed graft function and return to theatre for hypoperfusion.