Vasitis

Vasitis (plural: vasitides), also known as deferentitis (plural: deferentitides) , is an uncommon inflammatory disorder of the vas deferens and spermatic cord. It is classified as either the generally asymptomatic vasitis nodosa (seen after vasectomy) or acutely painful infectious vasitis. This article refers to the acute infective form as imaging is usually not undertaken in the chronic form, with very sparsely described radiologic findings.

Clinical presentation

Symptoms of acute vasitis are relatively non-specific and may include a painful swelling in the groin, symptoms of a urinary tract infection, or a dull ache in the pelvis. The infection may be severe with systemic signs of sepsis, and it may be misdiagnosed as other related acute urinary tract disorders such as epididymitis, orchitis, testicular torsion or prostatitis. It also mimics an acute inguinal hernia .

Pathology

The causative organism may be sexually transmitted infections such as Neisseria gonorrhea and Chlamydia sp., or a uropathogen such as Escherichia coli. Tuberculous vasitis has been described. Infections of the vas deferens may be associated with epididymo-orchitis and prostatitis or may be primary. It may be associated with urogenital surgery such as vasectomy, prostatectomy and hernia repairs.

Blood tests in vasitis usually show a leukocytosis. A urine culture may be negative.

Radiographic features

Ultrasound

Swelling of the inguinal canal with increased echogenicity of the fat may be seen. The region may appear hyperemic on color Doppler imaging, and there may be fluid within the canal. However, it is difficult to distinguish between an incarcerated inguinal hernia and vasitis using ultrasound alone .

CT

Swelling of the inguinal canal with increased density of fat both within and adjacent to the inguinal canal is seen . There may be hyperenhancement of the spermatic cord, extending to involve the vas deferens. An associated seminal vesicle abscess or seminal vesiculitis may be present, alongside a hydrocoele.

MRI

The edema of the inguinal canal and spermatic cord will be shown exquisitely on fluid-sensitive sequences .

Treatment and prognosis

Treatment is usually conservative with a course of oral antibiotics. Recovery is usually complete. No follow-up is required in uncomplicated cases. Surgical or radiologically guided drainage of abscesses may be required in severe cases.

Differential diagnosis

Due to the presentation with a painful inguinal swelling, the differential includes an incarcerated inguinal or femoral hernia. Imaging finding of a tubular structure within the inguinal canal in the setting of an acute presentation and a history of an orchiectomy may lead to a misdiagnosis of an Amyand hernia. This is postulated to occur due to distension of the vas deferens following an orchiectomy .

Practical points

Making a positive diagnosis of vasitis enables conservative management to be followed and avoids unnecessary surgery. Ultrasound may exclude mimics such as epidydmo-orchitis, but CT will be helpful in differentiating an acute inguinal hernia from vasitis. If MRI is available, it is the preferred modality as it avoids radiation and depicts the inflammatory changes very well.