Transscrotal Near Infrared Spectroscopy as a Diagnostic Test for Testis Torsion in Pediatric Acute Scrotum: A Prospective Comparison to Gold Standard Diagnostic Test Study.

PURPOSE: A rapid test for testicular torsion in children may obviate the delay for testicular ultrasound. In this study we assessed testicular tissue percent oxygen saturation (%StO2) measured by transscrotal near infrared spectroscopy as a diagnostic test for pediatric testicular torsion. MATERIALS AND METHODS: This was a prospective comparison to a gold standard diagnostic test study that evaluated near infrared spectroscopy %StO2 readings to diagnose testicular torsion. The gold standard for torsion diagnosis was standard clinical care. From 2013 to 2015 males with acute scrotum for more than 1 month and who were less than 18 years old were recruited. Near infrared spectroscopy %StO2 readings were obtained for affected and unaffected testes. Near infrared spectroscopy Δ%StO2 was calculated as unaffected minus affected reading. The utility of near infrared spectroscopy Δ%StO2 to diagnose testis torsion was described with ROC curves. RESULTS: Of 154 eligible patients 121 had near infrared spectroscopy readings. Median near infrared spectroscopy Δ%StO2 in the 36 patients with torsion was 2.0 (IQR -4.2 to 9.8) vs -1.7 (IQR -8.7 to 2.0) in the 85 without torsion (p=0.004). AUC for near infrared spectroscopy as a diagnostic test was 0.66 (95% CI 0.55-0.78). Near infrared spectroscopy Δ%StO2 of 20 or greater had a positive predictive value of 100% and a sensitivity of 22.2%. Tanner stage 3-5 cases without scrotal edema or with pain for 12 hours or less had an AUC of 0.91 (95% CI 0.86-1.0) and 0.80 (95% CI 0.62-0.99), respectively. CONCLUSIONS: In all children near infrared spectroscopy readings had limited utility in diagnosing torsion. However, in Tanner 3-5 cases without scrotal edema or with pain 12 hours or less, near infrared spectroscopy discriminated well between torsion and nontorsion.

Diagnosing Testicular Torsion before Urological Consultation and Imaging: Validation of the TWIST Score.

PURPOSE: The TWIST (Testicular Workup for Ischemia and Suspected Torsion) score uses urological history and physical examination to assess risk of testis torsion. Parameters include testis swelling (2 points), hard testis (2), absent cremasteric reflex (1), nausea/vomiting (1) and high riding testis (1). While TWIST has been validated when scored by urologists, its diagnostic accuracy among nonurological providers is unknown. We assessed the usefulness of the TWIST score when determined by nonurological nonphysician providers, mirroring emergency room evaluation of acute scrotal pain. MATERIALS AND METHODS: Children with unilateral acute scrotum were prospectively enrolled in a National Institutes of Health clinical trial. After undergoing basic history and physical examination training, emergency medical technicians calculated TWIST score and determined Tanner stage per pictorial diagram. Clinical torsion was confirmed by surgical exploration. All data were captured into REDCap™ and ROC curves were used to evaluate the diagnostic usefulness of TWIST. RESULTS: Of 128 patients (mean age 11.3 years) 44 (13.0 years) had torsion. TWIST score cutoff values of 0 and 6 derived from ROC analysis identified 31 high, 57 intermediate and 40 low risk cases (positive predictive value 93.5%, negative predictive value 100%). CONCLUSIONS: TWIST score assessed by nonurologists, such as emergency medical technicians, is accurate. Low risk patients do not require ultrasound to rule out torsion. High risk patients can proceed directly to surgery, with more than 50% avoiding ultrasound. In the future emergency medical technicians and/or emergency room triage personnel may be able to calculate TWIST score to guide radiological evaluation and immediate surgical intervention at initial assessment long before urological consultation.

DNA copy number variations in patients with 46,XY disorders of sex development.

PURPOSE: Less than 50% of cases of 46,XY disorders of sex development are genetically defined after karyotyping and/or sequencing of known causal genes. Since copy number variations are often missed by karyotyping and sequencing, we assessed patients with unexplained 46,XY disorders of sex development using array comparative genomic hybridization for possible disease causing genomic variants. MATERIALS AND METHODS: DNA from unexplained cases of 46,XY disorders of sex development were tested by whole genome array comparative genomic hybridization. In cases where novel copy number variations were detected parental testing was performed to identify whether copy number variations were de novo or inherited. RESULTS: Of the 12 patients who underwent array comparative genomic hybridization testing 2 had possible copy number variations causing disorders of sex development, both maternally inherited microdeletions. One case, with a maternal history of premature ovarian failure, had a cosegregating microdeletion on 9q33.3 involving NR5A1. The other case, with a maternal family history of congenital heart disease, had a cosegregating microdeletion on 8p23.1 upstream of GATA4. CONCLUSIONS: In this cohort copy number variations involving or adjacent to known causal genes led to 46,XY disorders of sex development in 2 of 12 previously unexplained cases (17%). Copy number variation testing is clinically indicated for unexplained cases of 46,XY disorders of sex development to aid in genetic counseling for family planning.

Prospective Evaluation of Predictors of Testis Atrophy After Surgery for Testis Torsion in Children.

OBJECTIVE: To prospectively correlate pain duration, red scrotal skin, ultrasound appearance of testis, and intraoperative testis color to future testis atrophy after acute testicular torsion. METHODS: Patients 2 months-18 years old with unilateral acute scrotum were consecutively enrolled in a National Institutes of Health transcutaneous near-infrared spectroscopy study, with a subgroup analysis of the true torsion group. Presence or absence of red scrotal skin, pain duration, testicular heterogeneity on preoperative ultrasound, and intraoperative testis color based on a novel visual chart 5 minutes after detorsion were recorded. All testes underwent orchiopexy regardless of appearance. Percent volume difference between normal and torsed testicles on follow-up ultrasound was compared between patients with and without risk factors. RESULTS: Thirty of 56 patients who had surgical detorsion underwent scrotal ultrasound at a mean of 117 days after surgery. A color of black or hemorrhagic 5 minutes after detorsion, pain duration >12 hours, and heterogeneous parenchyma on preoperative ultrasound were associated with significant testis volume loss in follow-up compared with normal testis. All patients with a black or hemorrhagic testis had >80% volume loss. Erythematous scrotal skin was not significantly associated with smaller affected testis volume in follow-up. CONCLUSION: Based on the high atrophy rate, orchiectomy can be considered for testes that are black or hemorrhagic 5 minutes after detorsion. Pain duration >12 hours and parenchymal heterogeneity on preoperative ultrasound were also associated with testis atrophy. Red scrotal skin was not a reliable predictor of atrophy and should not delay exploration.