Rare Vascular Complications in a Kidney Allograft

Introduction: The occurrence of vascular complications in kidney transplant ranges 6-30% and has a significant impact on allograft and patient outcomes. Case Description: Case 1: A 54-year-old male with ESKD from hypertension received a DDKT. He developed an AKI 5 weeks later. Ultrasound showed a 3 cm large extrarenal pseudoaneurysm (EPSA) at the site of anastomosis of the renal artery to the right external iliac artery. Endovascular intervention with occlusion of the pseudoaneurysm and intentional exclusion of transplant renal arteries was performed to prevent rupture and leak with eventual allograft failure. Case 2: A 25-year-old with ESKD from Alport’s syndrome and LUKT had an AKI, proteinuria, microscopic hematuria with ipsilateral leg edema 3 weeks later. Biopsy negative. External compression of the right common iliac vein by a 6 cm hilar lymphocele causing renal vein congestion was seen on imaging. Aspiration of the lymphocele resolved the findings. Discussion: EPSAs occur in 1% of transplants. Infections commonly cause EPSAs and can cause irreversible arterial damage. EPSA in our case was due to complex vasculature with 3 renal arteries on 2 aortic patches. Infected ESPAs or larger than 2.5 cm are at high risk for rupture and need intervention, usually allograft nephrectomy. Iliac vein stenosis is a rare, reversible cause of allograft AKI, ipsilateral leg edema, proteinuria and microscopic hematuria. This can be due to perihilar fluid collections or hematomas, surgical clamp injury and faulty suturing. In our case, a lymphocele led to a nutcracker-like phenomenon and renal vein congestion. Evolution and standardization of surgical techniques may have contributed to a decrease in vascular complications but the incidence remains substantial.