Validation of testicular workup for ischemia and suspected torsion score in patients with acute scrotum.

INTRODUCTION: The Testicular Workup for Ischemia and Suspected Torsion (TWIST) score was created to help physicians in the clinical evaluation of acute scrotum in which testicular torsion (TT) is suspected. There have been only a few reports on validation of the TWIST score since the original study was published.

OBJECTIVES: To validate the TWIST score as a scoring system.

PATIENTS AND METHODS: We reviewed the records of 106 patients with acute scrotum in our prospectively maintained database. The patients were divided into two groups by the final diagnosis: testicular torsion (group TT) or non-testicular torsion (group NTT). We retrospectively calculated the TWIST score of the patients. Patients were divided into low (0-2), intermediate (3-4), or high (5-7) risk groups according to the total score.

RESULTS: Fifteen patients (14%) had TT. The median age at presentation was 13.3 years (range 1.6-16.2) in group TT and 10.4 years (range 0.25-18.9) in group NTT, respectively. The sensitivity of clinical and Color Doppler ultrasonography (CDUS) findings to diagnose TT was 100%, whereas the specificity was 93.4%. Positive predictive value (PPV) and negative predictive value (NPV) were 71.4% and 100%, respectively. According to the calculated TWIST score, 65, 23, and 18 patients belonged to low, intermediate, and high risk groups, respectively. TT was found in 1(1.3%), 3(13%), and 11 (61%) patients of low, intermediate, and high risk groups, respectively. The NPV of the TWIST score for the low risk group was 98.5%, whereas the PPV of the TWIST score for the high risk group was 61.1%. Among the four patients with TT in low risk and intermediate risk groups, three patients presented to our institutions within 6 h after the onset. The torsion was 180° in two of the three patients.

CONCLUSION: The TWIST score can be useful for clinical diagnosis of testicular torsion, but is inferior to clinical findings along with CDUS. We should consider the possibility that a TWIST score could be underestimated when patients present with acute scrotum immediately after onset or the affected testis is mildly twisted.