Iliocaval Anomaly With Resulting Congestive Nephropathy: A Rare Etiology of Allograft Dysfunction Following Kidney Transplantation

Abstract

Background: Renal allograft dysfunction warrants prompt investigation as the differential diagnosis is often broad. Here, we present a pediatric kidney transplant recipient who experienced suboptimal allograft function due to previously undiagnosed inferior vena cava stenosis with resultant chronic congestive nephropathy.

Methods: We retrospectively reviewed a pediatric kidney transplant case at our own institution, and a literature review of congestive nephropathy was performed.

Results: The patient, a 13-year-old male with end-stage renal disease secondary to congenital renal dysplasia, underwent a preemptive living-related-donor kidney transplant. His postoperative course was complicated by the development of a lymphocele on posttransplant day 9, necessitating percutaneous drainage and the subsequent creation of a peritoneal window. Despite successful treatment of mild acute cellular rejection (as established by biopsy) and comprehensive evaluation to exclude alternative etiologies, his posttransplant kidney function remained suboptimal (calculated glomerular filtration rate around 40 mL/min/1.73 m²). Approximately 93 weeks posttransplant, he was found to have extensive venous thrombosis involving the iliocaval system and bilateral lower extremity deep veins. The patient underwent successful chemical thrombolysis and serial thrombectomy, resulting in a marked improvement in allograft function. Following thrombolysis, allograft function stabilized, suggesting that the underlying cause of persistent allograft dysfunction was chronic congestive nephropathy due to significant infrarenal inferior vena cava stenosis.

Conclusions: Iliocaval anomalies can contribute to unexplained kidney allograft dysfunction by causing chronic congestive nephropathy. Failure to recognize and address these anomalies may jeopardize graft function and heighten the risk of graft failure.

Keywords: allograft dysfunction; congestive nephropathy; inferior vena cava stenosis; kidney transplantation; vascular anomaly.

FIGURE 1

Trends of posttransplant serum creatinine and urine protein/creatinine ratio. No urine sample was collected during the time period denoted by the dashed line. POD, postoperative day.

FIGURE 2

(a–f) Representative images before and after treatment of extensive venous thrombosis. (a) pretreatment CT coronal view showing extensive venous clot burden in the IVC and iliac veins (black arrows) and IVC narrowing at the level right below the native renal veins (white arrow); (b) 3D reconstruction of the vasculature prior to treatment, in which the IVC is absent but showing the entire right external iliac vein and proximal left external iliac vein with extensive lumbar vein collaterals (white arrows) and a patent distal left external iliac vein (white triangles); (c) pretreatment CT coronal view showing transplant renal vein thrombosis extending from hilum to the iliac vein anastomosis (black arrows); (d) patent IVC on venogram, post‐thrombolysis; (e) patent transplant kidney venous vasculature, post‐thrombolysis; (f) patent pelvic vasculatures on follow up magnetic resonance angiography 2 months post‐treatment. CT, computed tomography; IVC, inferior vena cava.