A Rare Case of an Infectious Pseudoaneurysm due to Aspergillus flavus in the Setting of Renal Transplant

Renal transplant as a treatment option for end-stage renal disease (ESRD) is becoming increasingly prevalent. As with any other surgical intervention, complications may occur, including vascular ones. Pseudoaneurysms are particularly rare, with mycotic aneurysms reported in less than 1% of patients after renal transplant. Here, we present a case of an infected pseudoaneurysm involving the renal artery anastomosis, resulting in the explantation of the transplanted kidney. A 77-year-old man underwent deceased donor renal transplant for ESRD in the setting of diabetes and hypertension. He presented with acute kidney injury; a renal biopsy revealed mild active cellular rejection, treated with high-dose steroids. As renal function continued to deteriorate, a repeat renal biopsy was performed. During ultrasound-guided biopsy of the transplanted kidney, a possible aneurysm proximal to the anastomosis of the renal artery to the right external iliac artery was seen. A pelvic arteriogram showed a large 3 cm x 3.4 cm x 4 cm pseudoaneurysm arising directly off the right external iliac artery with the renal transplant artery filling from the distal side of this aneurysm. The patient was taken to the operation room for a re-exploration of his transplanted kidney and revision of the arterial anastomosis. Intraoperatively, necrotic tissue and purulence within the pseudo-aneurysm were noted with failure to salvage blood supply to the transplanted kidney; both the infected pseudo-aneurysm and renal transplant were resected. A portion of the aneurysm was sent to microbiology for culture; fungal cultures grew Aspergillus flavus. He was treated with isavuconazonium and improved clinically, though he subsequently expired following a sudden cardiac arrest. Given its rarity, most medical professionals will be unfamiliar with this unusual complication in renal transplant patients. Our case highlights the importance of pursuing imaging modalities to help identify vascular complications and discusses how to proceed after diagnosis is made. The importance of knowing this process is paramount in improving future patient outcomes.