Immediate postoperative sonography of renal transplants: vascular findings and outcomes.

Abstract

The purpose of this study was to determine the frequency and types of significant vascular findings on bedside sonography immediately after renal transplantation and which abnormalities would suggest a benefit from early surgical revision. Five hundred seventy-five renal transplant sonograms obtained within 4 hours of surgery were retrospectively reviewed for major vascular abnormalities: lack of renal artery (RA) or renal vein (RV) flow, elevated peak systolic velocity (PSV)>300 cm/s, parvus tardus waveforms, and markedly decreased or no color parenchymal flow. Clinical outcomes of abnormal cases were reviewed, including reoperations and percutaneous interventions. Thirty-two (5.6%) patients underwent repeat surgery within the first week, 16 for nonvascular causes. Forty-seven (8.2%) patients had positive sonography findings. In 16 patients, sonography impacted the decision for reoperation, with 14 confirmed vascular diagnoses: compartment syndrome (n=7), RV thrombosis (n=3), RA thrombosis (n=1), RA and RV thromboses (n=2), and vascular steal (n=1). All were salvaged except the three RV thromboses. Two patients had no vascular abnormality at surgery. All 16 had markedly decreased color flow and varying abnormalities of PSV and waveforms. Outcomes of the remaining 31 cases were infarct (n=1), renal or iliac artery stenoses eventually requiring stents (n=4), and normalized (n=26). These 26 had elevated PSV with normal or near-normal color flow. Unpaired Student t tests showed no significant difference in PSV between patients requiring surgery or stents and those who normalized (p=0.34). Immediate postoperative sonography has a spectrum of vascular findings, of which markedly decreased color flow is most likely to benefit from immediate reoperation.