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/display_record.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.