Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1893
RT Hydrocele
RT Testis
LT Testis
A
RT Testis
Trv
Sag B
FIG. 54.35 Extravaginal Testicular Torsion. Newborn with hard, nontender, left testicular mass. (A) Sagittal sonogram of the scrotum reveals
an enlarged, heterogeneous left testis with dilated rete testes. There are multiple foci of bright echogenicity surrounding the left testis, suggesting
an intrauterine torsion—“missed” torsion. Note the normal right testis with surrounding hydrocele. (B) Normal low is shown in the normal-appearing
right testis. However, a surrounding rim of color Doppler low can be seen around the avascular, swollen left testis.
A B C
FIG. 54.36 Types of Testicular Torsion. (A) Intravaginal torsion above the epididymis. (B) Extravaginal torsion. (C) Torsion of the testis below
the epididymis. (With permission from Leape LL. Torsion of the testis. In: Welch KJ, Randolph JG, Ravitch MM, editors. Pediatric surgery. St.
Louis, 1986, Mosby. 123 )
times, obstructing blood low. Torsion of the testis has the highest
prevalence during two age peaks—infancy and adolescence. 89
Two types of torsion have been described—extravaginal and
intravaginal, with the latter being more common. Extravaginal
torsion is generally found in neonates at the level of the spermatic
cord, which is poorly ixed in the inguinal canal. All the scrotal
contents are strangulated in this type of torsion. 89,100,118 Extravaginal
torsion is thought to occur in utero. 119 he loose attachment
of the spermatic cord and testes to surrounding structures
may account for increased mobility and may predispose to the
extravaginal type of torsion seen in neonates (Fig. 54.35). he
scrotum is swollen and red with a irm, painless enlarged testicle,
which is generally unilateral. Surgical salvage at birth is unlikely
because the testis is already necrotic, but occurrence of extravaginal
torsion ater birth demands emergency surgery. 120 he
ultrasound indings vary according to the duration of the torsion.
In more recent torsion, the testis is heterogeneously enlarged
with hypoechoic and hyperechoic areas. When the torsion is less
acute, the testis may be normal or slightly enlarged, with peripheral
echogenicity corresponding to calciications in the tunica
albuginea. Oten, associated scrotal skin thickening and hydroceles
are present. 118,119 here is no Doppler signal in the spermatic
cord or the testis. Chronic torsion ultimately leads to small
testicular size. Contralateral compensatory hypertrophy may be
seen. 121 Other conditions that mimic extravaginal torsion in
patients with a swollen scrotum in the neonatal period include
meconium peritonitis, intraperitoneal bleeding tracking through
the patent processus vaginalis, and tumor.
With intravaginal torsion the tunica vaginalis completely
surrounds the testis and inserts high on the spermatic cord,
preventing ixation of the testis to the scrotum and allowing the
testis to rotate freely on its vascular pedicle, known as the belland-clapper
deformity. 122 Another, less frequently encountered
type of intravaginal torsion is torsion of the mesorchium, the
tissue attachment between the testis and epididymis 89,97,123 (Fig.
54.36). In this situation, the testis twists within the tunica vaginalis
without torsion of the epididymis. Torsion within the scrotal
sac, or intravaginal torsion, may occur in any age group but is
seen more oten in adolescents and young adults. 89 he boys
develop sudden onset of scrotal or lower abdominal pain. here