Usefulness of Preoperative Ultrasound for the Evaluation of Testicular Rupture in the Setting of Scrotal Gunshot Wounds.

PURPOSE: A scrotal gunshot wound may result in testicular injury, necessitating urgent scrotal exploration and attempted testicular salvage. Scrotal ultrasound is highly sensitive and specific for testicular rupture in the setting of blunt scrotal trauma but it has been poorly studied in the setting of scrotal gunshot wounds. Our objective was to determine the accuracy of scrotal ultrasound to identify testicular rupture following a scrotal gunshot wound.

MATERIALS AND METHODS: We retrospectively reviewed the records of patients with a scrotal gunshot wound from 2003 to 2014 in whom preoperative ultrasound was done prior to scrotal exploration. A heterogeneous echo pattern of testicular parenchyma with contour loss was considered a positive examination for testicular rupture. Patients underwent scrotal exploration within 24 hours of presentation. The sensitivity and specificity of ultrasound were estimated and compared to operative findings. ROC curve analysis was done.

RESULTS: Of 75 patients who sustained a scrotal gunshot wound ultrasound was positive in 30 and negative in 45. No ultrasound revealed bilateral injuries. Scrotal exploration demonstrated a total of 40 testicular ruptures in 35 patients, of which 30 testicles were salvaged. Ten orchiectomies were performed. The sensitivity and specificity of ultrasound were 60% and 95%, respectively, with 16 missed injuries and 6 false-positive findings. Positive predictive value was 80% and negative predictive value was 87%. The ROC AUC was 0.79. In 6 of the 16 missed injuries there was an ipsilateral hematocele or hematoma.

CONCLUSIONS: The sensitivity of scrotal ultrasound is limited for evaluating testicular rupture after a scrotal gunshot wound. Large coincident hematoceles or hematomas may obscure the diagnosis of testicular rupture. Negative ultrasound should not preclude scrotal exploration after a scrotal gunshot wound is sustained.