Urinoma: Saviour of beleaguered kidney

Introduction: Spontaneous extravasation of urine due to High Pressure Chronic Retention is a rare entity. Most cases of urinoma are secondary to ureteric calculi. We present a case of left spontaneous perinephric urinoma with right hydroureteronephrosis with high pressure chronic retentiondue to benign enlargement of prostate. Summary: A 70 years male, with no comorbid illness, presented with left flank pain with overflow incontinence. On radiological evaluation, he was found to have distended urinary bladder, with right hydrouretronephrosis and left perinephric collection. Renal function tests were deranged. Patient was managed with per urethral catheter placement, antibiotics and ultrasound guided aspiration. Retention volume was more than one litre. Creatinine content of aspirated fluid was ten times higher to serum creatinine. Transurethral resection of prostate was done. The patient voided well after surgery. The urinoma resolved completely in 2 weeks. Follow up Contrast study revealed preserved left renal function; however the right hydroureteronephrotic kidney shrank in size. Conclusion: Spontaneous perinephric urinoma formation due to High pressure chronic retention was a blessing in disguise for the patient. It saved the affected kidney from getting knocked out. The other side hydroureternephrotic kidney suffered anatomical and functional loss.