Page 236 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Polyarteritis Nodosa 211

Angiography, which images areas of organ infarction, hematoma and microaneurysm
formation measuring 5 mm in diameter, identifies suggestive areas of arterial stenosis in up to
90% of patients with PAN. Angiography also depicts vascular lesions in renal, celiac, and
mesenteric vessels respectively in 54%, 24%, and 14% of patients, although even more often
in hepatic and splenic arteries [36, 67] without prognostic significance. While not rapidly
fatal, intraperitoneal ruptures of such aneurysms are treatable with selective arterial
embolization. Severe GI manifestations, like bowel perforations and ischemia, peritonitis and
intestinal occlusion, confer a poor prognosis [52]. Effective treatment combines prompt
surgical intervention and medical therapy with corticosteroid and immunosuppressive
treatment.

Testicular Manifestations

Unilateral orchitis and testicular tenderness due to testicular artery ischemia were
common findings in PAN, so noted in 17% of patients, although rarely the first manifestation
of disease [36, 69]. Indeed, orchitis was included in the 1990 ACR classification criteria of
PAN [4]; and although it typically improves with a prompt course of corticosteroids, however
in some instances it can be irreversible. Guillevin and coworkers [3] noted orchitis in
association with HBV-related PAN however an etiologic relation between viral infection and
testicular manifestations was not discerned.

Ureteral and Urogenital Manifestations

Ureteral manifestations are rare and ureteral stenoses appear to be more characteristic of
small-sized-vessel vasculitis SVV. Urodynamic and electrophysiological studies may
demonstrate detrusor hypoactivity in patients with voiding difficulty when the cause is
vasculitis of vasa nervorum supplying the bladder. It is unusual to discern a vasculitic spinal
cord etiology for bladder disturbances.

Pulmonary Manifestations

Unlike MPA, GPA and EGPA, pulmonary involvement in PAN is either asymptomatic or
subclinical, even when histopathologic involvement in found at postmortem examination.

Bone Manifestations

Periosteal involvement resulting from PAN develops mainly in the legs with associated
pain and localized edema, tissue biopsy of which may reveal underlying necrotizing
vasculitis [70].

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