Scrotal pain and testicular torsion: Viva

Branch 1: Classification and pathophysiology

The candidate should define testicular torsion as the twisting of the spermatic cord on its long axis that occludes the testicular blood supply and causes ischaemic testicular loss within hours. A strong candidate classifies it by where the twist occurs: intravaginal torsion, the common adolescent form inside the tunica vaginalis on a bell-clapper deformity; extravaginal torsion, the perinatal form where the whole cord and its coverings twist before the tunica fuses; and intermittent torsion, recurrent self-limiting episodes that risk a future complete torsion. [1]

If the examiner presses on the pathophysiology, the candidate should follow the blood. The twist compresses the thin-walled veins and lymphatics first, producing congestion and rising pressure within the inelastic tunica albuginea, and that rising pressure then collapses the artery, converting a congested perfused testis into an ischaemic one. The candidate should name the salvage gradient as the consequence: 90 to 100 percent within 6 hours, about 50 percent from 6 to 12 hours, and less than 20 percent from 12 to 24 hours, which is why time drives every decision. [1]

Branch 2: The TWIST score and the decision between theatre and imaging

If asked how to risk-stratify the acute scrotum, the candidate should describe the TWIST score, which awards one point each for testicular swelling, a hard testis, an absent cremasteric reflex, nausea or vomiting, and a high-riding testis, for a maximum of five. A score of 0 to 2 is low risk, 3 to 4 is intermediate risk, and 5 is high risk. The systematic review and meta-analysis by Qin and Qu confirmed the diagnostic performance of the score across the published cohorts. [5]

The candidate should state that this boy, with the swelling, the absent cremasteric reflex, the vomiting, and the high-riding testis, scores 5 and is high risk, so he goes straight to surgical exploration without imaging. Colour Doppler ultrasound is the imaging test of choice for the intermediate-risk boy, but it must never delay exploration in a high-probability presentation, and it can be falsely reassuring in early or partial torsion. The candidate should emphasise that the diagnosis is clinical and that a low threshold for exploration is the standard of care. [1]

Branch 3: The operation and the long-term outlook

If the examiner moves to the operation, the candidate should describe the urgent scrotal exploration under general anaesthesia. The testis is delivered, detorsed laterally to open the book, wrapped in warm saline, and assessed for viability by colour return and bleeding from an incision in the tunica albuginea. A viable testis undergoes ipsilateral orchidopexy with non-absorbable sutures, and a necrotic testis undergoes orchidectomy, with contralateral orchidopexy in every case because the bell-clapper deformity is bilateral in about 12 percent of boys. [1]

A strong candidate discusses the long-term fertility surveillance. After torsion, the disruption of the blood-testis barrier can trigger antisperm antibody formation and atrophy, and Aggarwal and colleagues documented the long-term impact on semen parameters and gonadal function, so a salvaged boy, and especially a boy who had an orchidectomy, is offered a semen analysis in adulthood with referral to a fertility service if abnormal. The candidate should conclude that a missed or delayed torsion is a lost testis and a preventable complaint, that a negative exploration is accepted, and that the family is counselled honestly at every stage. [7]