Page 310 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

284 Dimitri Chanouzas and Matthew David Morgan

Treatment
The mainstay of treatment in GCA is high dose corticosteroids to induce remission.

Methotrexate is recommended as an adjunctive therapy, while TNF- and interleukin (IL)-6
inhibitors may have a role in the treatment of relapsing and refractory disease [33, 47; 48]. A
comparison of the outcomes of 15 patients undergoing open revascularization for occlusive
mesenteric vasculitis secondary to TAK, polyarteritis nodosa (PAN), GCA and indeterminate
vasculitis compared to 163 patients undergoing open operations for atherosclerotic disease
[10] showed that both groups had similar freedom from mesenteric symptoms and primary
graft patency.

Medium Vessel Vasculitides

Ischemia and infarction in dependent organs associated with bleeding in the GIT and
within the abdominal cavity, and aneurysm formation occurs in the vasculitic involvement of
medium size vessels typified by PAN and KD.

Polyarteritis Nodosa

Epidemiology
This systemic necrotizing vasculitis is characterized by fibrinoid necrosis that typically

involves medium sized arteries [49]. It typically affects middle-age and older individuals with
a peak onset in the 6th decade of life. Hepatitis B virus (HBV) infection is associated in up to
one third of patients with PAN and is an important consideration with regards to treatment
and prognosis [50].

Classification and Diagnosis
Diagnosis of PAN entails the integration of clinical, angiographic and biopsy findings.

Angiographic evaluation is very helpful in the diagnosis and management of PAN. The gold
standard is conventional arteriography, with increasing utilization of body CT and MRI. The
typical findings are multiple aneurysms less than 1 cm in diameter that are most often found
in the distribution of the renal and mesenteric arteries, the superior mesenteric artery being
the commonest vessel involved in some series [15, 51]. The lesions classically affect branch
points and the bifurcation of arteries due to segmental erosion and inflammation that weakens
the arterial wall [3]. These aneurysms are not pathognomonic for the condition as they can
found in granulomatosis with polyangiitis (GPA) as well as in systemic lupus
erythematosus (SLE).

Clinical Features
Clinical features of PAN include constitutional symptoms such as malaise, weight loss

and fever as well as specific symptoms and signs reflecting the extent of multi-system
involvement [52] (Table 6).

Complimentary Contributor Copy