Acute renal failure due to subcapsular renal hematoma in a solitary kidney: improvement after decompression.

Abstract

Subcapsular renal hematomas occurring in the presence of a normally functioning contralateral kidney generally do not threaten renal function and, therefore, are managed expectantly. However, significant parenchymal compression of a solitary kidney may contribute to functional deterioration.1 We report a case of acute renal failure associated with a subcapsular hematoma in a solitary kidney. The pertinent clinical findings associated with this unusual clinical presentation and its successful management with urgent decompression are discussed. CASE REPORT A 56-year-old man with a remote history of right nephrectomy presented elsewhere with left flank pain. The patient had a history of recurrent left renal pelvic transitional cell carcinoma treated by multiple percutaneous interventions, most recently 1 month previously. At presentation serum creatinine was 4.3 mg./dl. (normal 0.7 to 1.4), which was increased from the baseline of 2.2 mg./dl. Diuretic renogram showed no evidence of obstruction. On physical examination left flank tenderness was noted. There was no evidence of gross or microscopic hematuria. Serum creatinine was 5.7 mg./dl. Urine output was approximately 1,000 ml. during the preceding 24 hours. Noncontrast enhanced computerized tomography revealed a 13 cm. left renal subcapsular hematoma with marked compression of the renal parenchyma and without hydronephrosis (fig. 1). Despite apparently sufficient urine output, the patient became increasingly symptomatic from volume overload and acidosis, and emergent hemodialysis was performed. Angiography demonstrated medial distortion of the renal vessels but failed to identify any source of active bleeding. Hemodialysis was again required on day 4 of hospitalization. Open surgical decompression was undertaken in the hope of salvaging renal function. A small flank incision provided access to the readily palpable, tense renal capsule. Once incised, approximately 1,000 ml. old blood and clot under pressure were decompressed. No active bleeding was identified. Renal function immediately improved with a self-limiting post-decompression diuresis of 5,460 ml. urine in 24 hours (fig. 2). Repeat renal angiography showed a small arteriovenous fistula, which was selectively embolized. Blood pressure did not vary significantly before, during or after intervention. At 6-month followup serum creatinine was 2.7 mg./dl. DISCUSSION