Page 235 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

210 Loic Guillevin

manifestations reflect secondary myocardial involvement so noted in up to 5% of patients
with PAN [57]; a frequency that increased to one-third in postmortem series [55].
Supraventricular cardiac arrhythmia and conduction disorders occur in 2 to 19% of PAN
patients [55, 58] due to arteritis of the sinus node and neighboring nerve fibers.

Aortic Dissection and Peripheral Vascular Manifestations

This author has not observed a case of PAN-related aortic dissection, a rare complication
that is attributed to diffuse vasculitis of the vasa vasorum which manifested in one such case
as fatal tamponade [59]. Dissection of proximal aortic branches and Raynaud phenomenon
when present may be complicated by vasonecrosis. Cryoglobulinemia may be found in
patients with cardiac disease and HBV-related PAN.

Gastrointestinal Manifestations

Gastrointestinal manifestations are among the most severe in PAN, affecting 38% of
patients [36], most often associated with HBV infection, so noted respectively in 50.4%
versus 31.1% of patients. While generally reflective of systemic involvement, they may also
be the initial findings of PAN [3]. Gastrointestinal complications are a major cause of death in
the first year of disease ranking third after infection and cardiac disease [60]. Abdominal pain
was the commonest symptom, so noted in 30 to 40% of patients with PAN and overall in 97%
of those with gastrointestinal involvement. The intensity and persistence of abdominal pain
despite corticosteroids treatment, suggests a vascular cause and confer a less favorable
prognosis [61]. Hemorrhage and small intestine perforation are the most feared manifestations
with respective reported frequencies of 20% to 50% and 2% to 40% (mean, 5%) [61]. When
present, ischemic vasculitis affects the small bowel and more rarely the colon and stomach.
Perforation of the esophagus is unusual; and vasculitis of the gallbladder occurs in 2% to 17%
of patients [62-64].

Vasculitic appendicitis may be the first manifestation of PAN or a localized form thereof.
Patients with isolated and histologically-proven vasculitic appendicitis progress to systemic
PAN within five years. The prognosis of closely monitored and surgically treated necrotizing
vasculitis of the gallbladder or appendix is generally favorable without immunosuppressant
treatment. Acute necrotizing and chronic pancreatitis, the latter often accompanied by
pseudocyst formation, were diagnosed in 3.7% of patients [36], however the prognosis is
extremely dismal because of the frequent association with small intestinal ischemia and
perforation. Exploratory surgery should be performed in such patients to detect
underdiagnosed bowel perforation. Digestive malabsorption and exudative enteropathy rarely
occurs. The liver and spleen can be involved with or without hematoma formation [65] that
may be clinically silent. One patient with fibrinoid necrosis of the splenic artery and later
splenic rupture was described [66]. When abdominal pain is present, computed tomography
(CT) and MRI of the abdomen can be useful to detect organ infarction and pancreatitis.
Gastric and colonic endoscopy can detect areas of ischemia and ulceration that precede
perforation. Gastrointestinal tissue biopsy rarely detects vasculitis.

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