The most common complications after renal trauma include prolonged urinary extravasation, delayed bleeding, arterial pseudoaneurysm, abscess, urinary fistula, and hydronephrosis. Renovascular hypertension may occur after renal trauma but is almost always transient. A rare, sustained hypertension is usually seen with subcapsular hematomas that exert significant parenchymal compression, causing decreased renal perfusion and subsequent release of renin (a phenomenon known as Page kidney).