Case Report: Early Spontaneous Subcapsular Hematoma in a Transplanted Kidney: The Importance of High Suspicion and Timely Intervention.

Background: Subcapsular hematoma (SH) is a rare but serious complication after renal transplantation, potentially leading to graft dysfunction. Through external compression and activation of the renin-angiotensin-aldosterone system a SH can lead to a serious condition known as Page kidney. Early diagnosis and timely intervention are crucial to prevent graft loss.

Case presentation: We describe a 67-year-old male who underwent kidney transplantation and developed an SH in the immediate postoperative phase. Despite being hemodynamically stable and asymptomatic, the patient exhibited persistent anuria and rising serum creatinine levels (349 μmol/L). Routine ultrasound (US) revealed a SH (2.5 cm × 4.3 cm × 7.8 cm) compressing the graft. Doppler findings showed normal renal arterial resistive indices. A subsequent non-contrast CT scan confirmed the diagnosis. Given the risk of graft ischemia, surgical decompression via longitudinal and transverse capsular incisions was performed. Postoperatively, diuresis resumed, and renal function improved, with a decline in creatinine levels. The patient was discharged on postoperative day 25 with preserved graft function.

Conclusion: SH in transplant recipients is uncommon and often linked to surgical trauma, anticoagulation, or allograft biopsy. While small hematomas may resolve conservatively, larger ones can lead to graft dysfunction. This case highlights the importance of routine postoperative US for early detection, as well as the role of timely surgical intervention in preserving renal function. Given the potential for irreversible ischemia and graft loss, proactive surgical decompression should be favored over conservative management in transplant recipients with significant SH.