Testicular torsion is a urological emergency requiring surgical intervention. It occurs when there is twisting of the spermatic cord with rotation of the testicle. It is an emergency due to the compromised blood supply which leads to ischaemia and ultimately necrosis.
It has a peak incidence in teenagers aged 13-15 years old but can occur at any age.
Pathophysiology
The testicle descends through the inguinal canal to enter into the scrotum. It has a layer of the peritoneum attached (known as the tunica vaginalis). The attachment points for the tunica vaginalis are normally at the superior and inferior regions of the spermatic cord. However, if both attachment sites are at the superior end this may lead to a bell clapper deformity which is associated with an increased likelihood of testicular torsion due to its increased mobility.
Torsion leads to ischaemia as the blood vessels become compromised with the twisting nature. This ischaemia can lead to germ cell death on the affected side. The contralateral testicle also has been shown to have issues relating to spermatogenesis. This may be due to inflammation and free radical formation but the mechanism is not as clear.
Once ischaemia has set in there is a period of 4-6 hours in which the testicle may still be viable if de-torsion occurs beforehand. If de-torsion is delayed until after this timeframe (more than 10-12 hours) we will see irreversible testicular damage and necrosis. This may be variable as the number of rotations may also affect how viable the tissue is.
The spermatic cord is a collection of vessels, nerves and ducts that are surrounded by fascia. It runs from the inferior abdomen (deep inguinal ring) → scrotum (entering via the superficial inguinal ring).
It’s contents include:
- Vessels
- Testicular artery
- Cremasteric artery and vein
- Artery to the vas deferens
- Pampiniform venous plexus
- Nerves
- Genital branch of the genitofemoral nerve
- Parasympathetic and sympathetic fibers
- Other contents include:
- Lymphatic vessels
- Vas deferens
- Processus vaginalis - a projection of the peritoneum that allows for testicular descent in the developing embryo. This closes as an adult (usually).
🔢 Classification
We can classify testicular torsion in 3 ways based on how it occurs:
- Intra-vaginal torsion
- Extra-vaginal torsion
- Torsion due to long mesorchium
This occurs due to the tunica vaginalis attaching too high on the spermatic cord which allows more opportunity for rotation of the testicle with the bell clapper deformity.
This is also known as neonatal testicular torsion as it mainly affects neonates. This is because the tunica vaginalis’ attachment to the scrotum is not fully formed and therefore the testis and tunica vaginalis may undergo torsion. This is why we have to assess for cryptorchidism (undescended testes).
The mesorchium is a band of connective tissue attaches to efferent ductules of the epididymis. If they are elongated the testes may twist upon a fixed epididymis.
⚠️ Risk factors
- Age 12-25 years
- Previous testicular torsion
- Family history of testicular torsion
- Cryptorchidism
😷 Presentation
- Suden onset of severe unilateral testicular pain
- Referred abdominal pain
- High riding testis - this is when the affected testis is positioned higher than the unaffected side.
- Erythematous scrotum
- Horizontal laying testis - the affected testis may be lying on the horizontal axis.
- Negative Prehn’s test - the pain will not diminish when elevating the scrotum (unlike in epididymitis where the pain may diminish with elevation).
- Absent cremasteric reflex - this reflex occurs when striking the inner upper thigh. It results in contraction of the cremaster muscle → elevation of the scrotum. The contraction usually occurs due to sensory afferents from the ilioinguinal nerve travelling up the spinal cord and activating the efferent motor fibres of the genital branch of the genitofemoral nerve (which innervated the cremaster muscle).
The hydatid of Morgagni is an appendage that is a vestigial remnant of the Müllerian duct (the embryonic structure that develops into the female reproductive tract). This appendage may also become torted).
It may present similarly with sudden onset of pain with a normal lie and less erythema. There may be blue dot sign that is present in the upper half of the hemiscrotum (due to visible infarction of the hydatid).
🔍 Investigations
The diagnosis of testicular torsion primarily relies on clinical diagnosis based on the clinical features. We can do further investigations to confirm the diagnosis and rule out other differentials.
Certain things we may do to rule in/out torsion include:
- Cremasteric reflex - this is not always absent in torsion but it is a feature that is suggestive of testicular torsion if absent.
- Doppler ultrasound - may show reduced blood flow to the affected testicle (as opposed to increased blood flow in epididymitis). We may also see a whirlpool sign which is a spiral twist in the course of the spermatic cord that is seen on ultrasound.
- Urinalysis - may rule out infection or UTI.
🧰 Management
As mentioned previously, we need to fix the ischaemia within 4-6 hours to keep the testis viable. Torsion lasting more than 10-12 hours is likely to lead to irreversible damage.
- Urgent surgical exploration - this is warranted. It involves assessing the testis and spermatic cord for evidence of torsion. Analgesia and anti-emetics are provided pre-operatively.
Surgical management may be provided if torsion is confirmed:
- De-torsion with bilateral orchidopexy - this means the testis will be untwisted and both testicles will be fixed to the scrotum.
- In the cases where the testis is non-viable → orchidectomy will be done. A prosthesis may be inserted at the time of surgery or at a later stage.
🚨 Complications
- Testicular atrophy - this may still occur after surgery.
- Chronic pain
- Infertility
- Palpable suture
- Psychological implication and cosmetic deformity - this may be mitigated with a prosthetic.
- Recurrent torsion