Delayed-Onset Renal Allograft Compartment Syndrome in a Pediatric Kidney Transplant Recipient: The Role of Surgical Re-Evaluation

Background: Renal allograft compartment syndrome (RACS) represents a rare and potentially underdiagnosed cause of allograft dysfunction, typically occurring in the immediate post-transplant period. However, delayed-onset RACS remains underrecognized. Methods: We present a case of a 14.5-year-old girl with nephronophthisis, who received a kidney transplant from her father and who was diagnosed with late-onset renal allograft compartment syndrome on post-transplant day 20. Results: In the post-transplant follow-up of this patient, the serum creatinine level increased from the 2nd day. On day 5, surgical re-evaluation was performed as she did not respond to acute rejection therapy with prednisolone, anti-human T-lymphocyte immunoglobulin, and plasmapheresis. Although macroscopic examination of the allograft did not reveal any abnormalities, serum creatinine levels rapidly returned to normal after surgery. However, on the 20th day, serum creatinine started to rise again. Calcineurin toxicity and infectious causes have been ruled out. She received treatment with immunoadsorption and intravenous immunoglobulin as the second biopsy showed glomerulitis and tubulitis. Despite these treatments, the serum creatinine level increased to 6 mg/dL, and she was reassessed surgically. Although the allograft appeared normal, there was edema in the surrounding tissue. Serum creatinine levels returned to normal (0.9 mg/dL) spontaneously after surgery. So, she was diagnosed with late-onset renal allograft compartment syndrome due to the edema surrounding the allograft and improvement observed in serum creatinine levels after fascia opening. Conclusions: RACS should be considered beyond the immediate post-transplant period, particularly when standard interventions fail to improve graft function. Surgical exploration remains a critical diagnostic and therapeutic tool in such cases.