Society For Pediatric Urology

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Use of the TWIST Score for Risk Stratification of Children with Testicular Torsion: Testicular Firmness Predicts Need for Orchiectomy
Jackson Cabo, BA1, Chevis Shannon, MPH, MBA, DrPH2, Heidi Chen, PhD3, John Thomas, MD4.
1Vanderbilt University School of Medicine, Nashville, TN, USA, 2Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA, 3Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN, USA, 4Department of Urology, Vanderbilt University Medical Center, Nashville, TN, USA.

Background: Testicular torsion is rare, but may cause significant morbidity, such as testicular loss and psychologic trauma. The TWIST (Testicular Workup for Ischemia and Suspected Torsion) score, a clinical tool first described by Barbosa and colleagues in 2013, has been shown to be effective in predicting a diagnosis of torsion with high sensitivity and specificity. However, the use of TWIST score components to predict adverse outcomes has not been investigated. We sought to determine if clinical components of the TWIST score are associated with need for orchiectomy in patients with testicular torsion.
Methods: We performed a retrospective chart review of 133 patients with surgically confirmed testicular torsion treated at our facility from January 2008 to July 2017. Separate TWIST scores were generated based on documentation recorded by emergency department (ED) and urology providers. Each of the five components (testicular swelling, hard testicle, nausea/vomiting, absent cremasteric reflex, and high riding testicle) were reported to be present, absent, or missing from the medical record. Associations with need for orchiectomy were determined using Fisher’s exact and Wilcoxon tests. Multivariable logistic regression was performed to assess for associations with need for orchiectomy after controlling for time from symptom onset and hospital presentation to treatment. All statistical tests were 2-tailed with p<0.05 deemed significant.
Results: Out of the 133 patients included in the study, 60 (45%) required orchiectomy. On assessment by an emergency medicine physician, patients with testicular swelling (93 vs. 77%;p=0.013) and hard testicle were more likely to require orchiectomy (44% vs. 21%;p=0.015). Likewise, patients with testicle loss were significantly more likely to have a hard testis on exam as noted by their urologist (78% vs. 39%;p<0.001) while testicular swelling (90% vs. 77%;p=0.07) also trended toward significance. Of these components, the presence of a hard testis noted by a urologist significantly predicted the likelihood of orchiectomy on multivariable analysis (Table 1; OR 5.75;p=0.03).
Conclusions: The TWIST score is useful in detecting testicular torsion, but it is not widely implemented in many settings, including our own practice. Applying the TWIST score to previously treated patients, we found that the presence of testicular firmness on exam was associated with a higher risk for testicular loss. While confirmatory studies are needed, this association could aid clinicians in providing patients realistic expectations prior to surgery. These findings have prompted a multi-disciplinary quality improvement initiative with the departments of urology and emergency medicine to assess the usefulness of the TWIST score as part of a standardized clinical protocol.
Table 1. Multivariable logistic regression model of orchiectomy predictors. Our model was adjusted for time from presentation to intervention, time from symptom onset, and time to operating room.
OR95%-CIP-value
Urology Consult Exam
Testicular Swelling (yes vs. no)2.240.25-20.380.48
Hard Testicle (yes vs. no)5.751.13-29.140.03
Nausea/Vomiting (yes vs. no)0.550.20-1.510.25
Cremasteric Reflex (no vs. yes)4.230.37-48.190.24
High-Riding Testicle (yes vs. no)1.260.33-4.820.73
ED Exam:
Testicular Swelling (yes vs. no)1.96-0.23-6.850.09
Hard Testicle (yes vs. no)0.31-2.39-5.290.85
Nausea/Vomiting (yes vs. no)0.350.11-1.170.09
Cremasteric Reflect (no vs. yes)4.510.46-43.880.19
High-Riding Testicle (yes vs. no)1.630.16-16.130.68


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