This includes epididymo-orchitis, torsion of a testicular appendage, and causes of flank pain with radiation into the groin and testis. From time to time the pain of a ureteric stone may be localised to the ipsilateral testis, but when the testis is palpated, the patient has no tenderness. In such cases a computed tomography urogram (CTU) confirms the presence of a stone.
Clinically, the pain of a twisted appendix testis or appendix epididymis can be difficult to distinguish from that of a testicu-lar torsion. Sometimes, though, a little boy presents with scrotal pain and the area of tenderness on examination of the scrotum is confined almost to a single spot, which can be localised by the
6. SCROTAL AND GENITAL EMERGENCIES 129
tip of the examining finger (Fig. 6.4). We have never felt comfortable relying on this sign to exclude a testicular torsion and have always explored such cases.
Both colour Doppler ultrasound and radionuclide scanning can be used to diagnose testicular torsion (Al Mufti et al. 1995). Colour Doppler ultrasound shows reduced arterial blood flow in the testicular artery. Radionuclide scanning shows decreased uptake of the radioisotope in the affected testis, an indication of absent blood flow to that testis (Melloul et al. 1995). Useful though these tests may be, they are not readily available in many hospitals. In the case of Doppler ultrasound scanning, the testis may be too tender to allow the pressure of the ultrasound probe to be applied.
The mainstay of investigation and treatment of a suspected case of testicular torsion remains, in many hospitals, scrotal exploration. This should be undertaken as a matter of urgency. Delay in relieving the twisted testis can result in permanent ischaemic damage to the testis with subsequent atrophy, loss of hormone production, and loss of sperm production. Furthermore, as the testis undergoes necrosis, the blood-testis barrier breaks down and an autoimmune reaction has been shown to develop (sympathetic orchidopathia), in animal models (Cerasaro et al. 1984, Wallace et al. 1982). Whether this occurs in humans to the extent that spermatogenesis is impaired is uncertain (Anderson and