Allograft artery mycotic aneurysm after kidney transplantation: A case report and review of literature

Abstract

Background: Allograft artery mycotic aneurysm (MA) represents a rare but life-threatening complication of kidney transplantation. Graftectomy is widely considered the safest option. Due to the rarity of the disease and the substantial risk of fatal consequences, experience with conservative strategies is limited. To date, only a few reports on surgical repair have been published. We describe a case of true MA successfully managed by aneurysm resection and arterial re-anastomosis.

Case summary: An 18-year-old gentleman, on post-operative day 70 after deceased donor kidney transplantation, presented with malaise, low urinary output, and worsening renal function. Screening organ preservation fluid cultures, collected at the time of surgery, were positive for Candida albicans. Doppler ultrasound and contrast-enhanced computer tomography showed a 4-cm-sized, saccular aneurysm of the iuxta-anastomotic segment of the allograft artery, suspicious for MA. The lesion was wide-necked and extended to the distal bifurcation of the main arterial branch, thus preventing endovascular stenting and embolization. After multidisciplinary discussion, the patient underwent surgical exploration, aneurysm excision, and re-anastomosis between the stump of the allograft artery and the internal iliac artery. The procedure was uneventful. Histology and microbiology evaluation of the surgical specimen confirmed the diagnosis of MA caused by Candida infection. Three years after the operation, the patient is doing very well with excellent allograft function and no signs of recurrent disease.

Conclusion: Surgical repair represents a feasible option in carefully selected patients with allograft artery MA. Anti-fungal prophylaxis is advised when preservation fluid cultures are positive.

Keywords: Aneurysm; Candida; Case report; Complication; Infection; Kidney transplant.

Figure 1

Color Doppler ultrasound scan of the transplanted kidney. A: Rounded, 3.8 cm-sized, hypoechoic mass localized between the hilum of the allograft and the iliac vessels (blue arrow); B: Turbulent intra-lesional flow (yin-yang sign) along the renal allograft artery (blue arrow).

Figure 2

Abdominal contrast-enhanced computed tomography scan. A: Saccular dilation of the iuxta-anastomotic segment of the renal allograft artery, measuring 3.2 cm × 3.5 cm × 4.0 cm (white arrow); B: The aneurysm involves the main branch and extends to the bifurcation of the renal allograft artery (white arrow).

Figure 3

Intra-operative finding. A: Large bulging aneurysm causing pressure effects on the transplanted kidney (white arrow); B: The aneurysm is saccular, wide-necked, and involves the main branch of the renal allograft artery (white arrow).

Figure 4

Surgical repair. A: Aneurysm excision (white arrow); B: End-to-end anastomosis between the stump of the renal allograft artery and the internal iliac artery (white arrow).

Figure 5

Post-operative magnetic resonance imaging of the transplanted kidney showing the reconstructed renal allograft artery with no signs of recurrent disease (white arrow).