Torsion of the Testis

Definition

• Incidence: 3.8-4.5 per 100,000 males under 18 years annually
• Accounts for 10-15% of acute scrotal disease in children
• Most common between ages 10 and 25 years

Pathophysiology

Types of Torsion

• Seen almost exclusively in neonates
• Occurs due to increased mobility of the testicle before it descends into the scrotum and becomes attached to the scrotal wall via the tunica vaginalis
• The entire spermatic cord, including the tunica vaginalis, twists

• The predominant type beyond the neonatal period
• Results from one or more anatomical predispositions:

Figure: (a) Normal attachment, (b) Abnormally high attachment (bell-clapper deformity) - the tunica vaginalis investment is too high, allowing free rotation, (c) Separation of testis from epididymis - torsion about the pedicle between them - Bailey & Love, 28th Ed.

Precipitating Factors

• Physical activity (straining, lifting, sport)
• Sexual activity
• Thermal stimulation
• Occasionally occurs during sleep (cremasteric reflex while waking)

Degree of Torsion and Ischaemia

• Twists of 720° cause more rapid ischaemia than twists of 360° or less
• Duration-dependent damage: venous outflow obstructed first, then arterial inflow
• Contralateral testicular biopsy findings are abnormal in 57-88% of males when torsion occurs, suggesting underlying bilateral spermatogenic dysfunction

Consequence of Torsion

• Up to 50% of men develop adverse spermatogenic effects after torsion
• 36-39% will have sperm concentrations below 20 million/mL
• Up to 11% develop antisperm antibodies due to disruption of the blood-testis barrier (tight junctions between Sertoli cells)

Clinical Features

Differential Diagnosis

Investigations

Clinical Priority First

1. Doppler Ultrasound (most commonly used)

• Can confirm absence of blood flow to the affected testis
• Sensitivity 92-100% for confirming epididymitis
• Absence of blood flow = torsion until proven otherwise
• Caveat: False-positive results (apparent flow) can occur, so it is not routinely recommended as a reason to withhold surgery. A positive Doppler (flow present) does not absolutely exclude torsion.

2. Radionuclide Scanning (Technetium-99m scan)

• Uptake of tracer into the centre of the testis rules out torsion
• Less available, rarely used in acute setting

3. Urinalysis

• Normal in testicular torsion (WBCs and bacteria suggest epididymo-orchitis)

4. FBC/Bloods

• Leukocytosis suggests infection rather than torsion
• No specific blood test for torsion

Key principle from Smith & Tanagho's General Urology:

"The presence of blood flow in the testis on Doppler ultrasonography or uptake of tracers into the center of the testis on radionuclide scanning rules out torsion."

Management

Time is Testis - Salvage Rates by Duration

Step 1: Immediate Urological Consultation

Step 2: Manual Detorsion (can be attempted in ED)

• Testis usually rotates medially (inward), so manual detorsion involves rotating it outward (laterally), like opening a book
• If successful, pain relief is immediate and vascular flow restored
• This is a temporising measure only - does not negate need for surgical fixation

Step 3: Emergency Surgical Exploration

• Fix with 3 non-absorbable sutures between the tunica albuginea and the scrotal raphe (orchiopexy)
• Absorbable sutures must NOT be used (risk of recurrent torsion as suture dissolves)
• Fix the contralateral testis as well - the anatomical predisposition is bilateral

• Wrap the testis in a warm swab and observe for several minutes
• Make a small incision in the tunica albuginea - if bright red arterial bleeding is seen, the testis may survive
• Fix as above if viable

• Orchiectomy is performed - the dead testis must be removed
• Counsel the patient about testicular prosthesis later
• Still fix the contralateral testis to prevent future torsion

Step 4: Contralateral Orchiopexy

Step 5: Cases With Prolonged History (Several Days)

• The affected testis will already be infarcted
• Little can be gained (other than pain relief) by immediate exploration of the affected side
• However, urgent contralateral fixation is still necessary

Orchiopexy Techniques (for intermittent/elective cases)

1. Suture fixation - 3-0 non-absorbable sutures fixing tunica albuginea to dartos muscle or scrotal raphe
2. Dartos pouch procedure - testis placed in a subcutaneous pouch between dartos and external spermatic fascia, secured by purse-string suture; preferred by some as it avoids intratesticular vessel injury

Summary Algorithm

Acute Scrotal Pain
      ↓
High clinical suspicion for torsion?
      ↓
YES → Emergency surgical exploration (do not delay)
      ↓
Viable testis? → Bilateral orchiopexy (non-absorbable sutures)
Infarcted?    → Orchiectomy + contralateral orchiopexy

NO / Uncertain → Doppler ultrasound
      ↓
No flow → Emergency exploration
Flow present + confident alternative diagnosis → Treat accordingly

• Bailey and Love's Short Practice of Surgery, 28th Ed., pp. 1582-1584 (Torsion of the Testis)
• Campbell-Walsh-Wein Urology, 3-Volume Set, pp. 1612-1614; 1180-1184 (Testis Torsion; Intermittent Torsion)
• Smith and Tanagho's General Urology, 19th Ed., p. 787 (Distinguishing Torsion)
• Rosen's Emergency Medicine: Concepts and Clinical Practice, p. 1595 (Disposition and Management)