Diagnostic Ultrasound - Abdomen and Pelvis

Testicular Torsion/Infarction
Diagnoses: Scrotum
PATHOLOGY
General Features
• Etiology
○ Most occur spontaneously; rarely occurs due to
traumatic etiology
• Varying degrees of ischemic necrosis & fibrosis depending
on duration of symptoms
• Undescended testes have increased risk of torsion
• Exocrine and endocrine function is substandard in men with
history of unilateral torsion; the following 3 theories explain
the contralateral disease noted in torsion
○ Unrecognized or unreported repeated injury to both
testes
○ Preexisting pathologic condition predisposing both
testes to abnormal spermatogenesis and torsion of
spermatic cord
○ Induction of pathologic changes in contralateral testis by
retention of injured testis
Staging, Grading, & Classification
• Intravaginal torsion: Common type, most frequently occurs
at puberty
○ Torsion occurs within tunica vaginalis
○ 2 predisposing conditions
– Long stalk of mesentery or spermatic cord leading to
anomalous suspension of testis
– Bell clapper deformity where tunica vaginalis
completely encircles epididymis, distal spermatic cord,
and testis rather than attaching to posterolateral
aspect of testis
○ Anomalous testicular suspension is bilateral in 50-80%
○ 10-fold increased incidence of torsion in undescended
testis after orchiopexy
• Extravaginal torsion: Exclusively in newborns
○ No bell clapper deformity
○ Torsion occurs outside tunica vaginalis when testes and
gubernacula are not fixed and are free to rotate
○ Infarcted and necrotic testis at birth
Gross Pathologic & Surgical Features
• Purple, edematous, ischemic testicle, may rapidly reperfuse
when manually detorsed
Microscopic Features
• Hemorrhagic, interstitial edema; necrosis
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Acute scrotal/inguinal pain; swollen, erythematous
hemiscrotum without recognized trauma
○ Pain not relieved by elevation of scrotum
○ Absent cremasteric reflex
• Clinical profile
○ Young male with acute scrotal pain
Demographics
• Epidemiology
○ Infant & adolescent boys most often affected
Natural History & Prognosis
• Testis usually turns medially up to 1,080°, 3 full revolutions
○ Venous obstruction occurs 1st, followed by obstruction
of arterial flow, which leads to testicular ischemia
○ Diminished blood flow in testis with twist of 180° or less
○ Testicular viability depends on degree of torsion and
duration of symptoms
• Surgical emergency: Testicular infarction if not treated
promptly
Treatment
• Surgical exploration; detorsion; bilateral orchidopexy if
viable testicle
○ Nonviable testicle usually removed; higher risk of
subsequent torsion on contralateral side
• Delaying surgical intervention worsens intraoperative
testicular salvage rate and extent of subsequent testicular
atrophy
• Reducing time lag between onset of symptoms and time of
surgical or manual detorsion is of utmost importance in
preserving viable testis
• Salvage rate of testis vs. time interval between onset of
pain and surgery
○ 80-100% → < 6 hours
○ 76% → 6-12 hours
○ 20% → 12-24 hours
○ 0% → > 24 hours
DIAGNOSTIC CHECKLIST
Consider
• Normal US (grayscale & Doppler) does not exclude early or
partial torsion
○ Repeat examination at 1-4 hour intervals if
conservatively managed
Image Interpretation Pearls
• Decreased or absent flow on Doppler ultrasound
SELECTED REFERENCES
1. Esposito F et al: The "whirlpool sign", a US finding in partial torsion of the
spermatic cord: 4 cases. J Ultrasound. 17(4):313-5, 2014
2. Yusuf GT et al: A review of ultrasound imaging in scrotal emergencies. J
Ultrasound. 16(4):171-8, 2013
3. Yagil Y et al: Role of Doppler ultrasonography in the triage of acute scrotum
in the emergency department. J Ultrasound Med. 29(1):11-21, 2010
4. Schalamon J et al: Management of acute scrotum in children--the impact of
Doppler ultrasound. J Pediatr Surg. 41(8):1377-80, 2006
5. Vijayaraghavan SB: Sonographic differential diagnosis of acute scrotum: realtime
whirlpool sign, a key sign of torsion. J Ultrasound Med. 25(5):563-74,
2006
6. Dogra V et al: Acute painful scrotum. Radiol Clin North Am. 42(2):349-63,
2004
7. Dogra VS et al: Torsion and beyond: new twists in spectral Doppler
evaluation of the scrotum. J Ultrasound Med. 23(8):1077-85, 2004
8. Dogra VS et al: Sonography of the scrotum. Radiology. 227(1):18-36, 2003
9. Arce JD et al: Sonographic diagnosis of acute spermatic cord torsion.
Rotation of the cord: a key to the diagnosis. Pediatr Radiol. 32(7):485-91,
2002
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