LAUSR

A 53-year-old male with end-stage kidney disease secondary to Alport syndrome and a deceased donor kidney transplant 7 years prior, presented with oliguria and right lower quadrant tenderness over the allograft site. One year previously , the patient had an uneventful kidney allograft biopsy which revealed chronic active antibody-mediated rejection. On presentation, the patient was hypertensive, with a blood pressure of 195/95 mmHg and pulse of 84. Investigations revealed that hemoglobin had decreased from 8.3 to 6.7 g/ dL requiring transfusion and had developed acute on chronic kidney injury, with a serum creatinine (SCr) of 7.06 mg/ dL compared to a baseline of 2.62 mg/dL. An abdominal CT scan, without contrast media, confirmed a spontaneous subcapsular renal hematoma compressing the kidney parenchyma, consistent with Wunderlich syndrome (Fig. 1). Hemodialysis was performed. Following 72 h of bed rest, kidney function improved to 3.40 mg/dL, and the patient was discharged off dialysis. Wunderlich syndrome, or spontaneous perirenal hemorrhage (SPH), refers to spontaneous non-traumatic bleeding in the perinephric or subcapsular space, most commonly caused by renal neoplasms or vascular abnormalities [1]. Patients may present with Lenk’s triad, characterized by acute flank pain, flank mass, and hypovolemic shock. Compression of the renal parenchyma in this case led to a Page kidney phenomenon, in which kidney hypoperfusion stimulates the renin–angiotensin–aldosterone system, resulting in marked hypertension. Management options for SPH include conservative treatment, surgery, and transarterial embolization. Surgical management is recommended for cases secondary to malignancy and includes hematoma evacuation and nephrectomy. Transarterial embolization is increasingly favored over surgery and spares the kidney parenchyma, although there is a low risk of kidney infarction and recanalization [2]. Over the next 6 months the patient experienced two recurrences of Wunderlich syndrome, without any identified precipitant event. The etiology was considered to be most likely secondary to the previous allograft biopsy, having led to arteriovenous fistula formation. However, the patient declined CT angiography, percutaneous hematoma drainage, and transarterial embolization. Following the second recurrence, the patient was discharged with a serum creatinine of 5.41 mg/dL and with a plan to initiate chronic hemodialysis.