These arise usually by extension of the infective process to the arteries, and are generally part of a larger and more pronounced lesion.

Syphilitic affections of the arteries occur in the neighbourhood of gummata, more especially of the brain and its membranes. There is an extension of the specific inflammation to the walls of the artery, so that the coats are infiltrated with round cells. The internal coat may undergo great thickening, so that the condition resembles that in obliterating endarteritis (see Fig. 126, p. 302). A more unusual syphilitic lesion is a localized inflammation of an artery without the presence of a gumma in the neighbourhood. The artery is thickened and has a cartilaginous consistence, while the calibre is greatly reduced. This condition, which occurs chiefly in the arteries of the brain, resembles, atheroma of these vessels, but is more limited in its distribution.

There is considerable doubt as to the existence of a special gummatous endarteritis as described by Heubner, and the influence of syphilis in affecting the arteries has been exaggerated. A lesion of an artery is not to be regarded as syphilitic unless it be either directly connected with a syphilitic lesion, or, in the absence of a general atheroma, is associated with syphilitic disease elsewhere.

Tuberculosis of organs not infrequently extends to their arteries. The wall of the artery is infiltrated with round cells and its tissue opened out and softened. There may result aneurysm or even haemorrhage, although the advancing tuberculosis usually closes the artery by thrombosis. (See under Tuberculosis of the lungs).

Literature

Crisp., Treatise on structure, diseases and injuries of blood-vessels, 1847; Koster, Pathogenese d. Endarteritis, 1874; Friedlander (Arteritis obliterans) Virch. Arch., lxiii., 355; Stilling, Heilung durchschlungener Gefasse, 1834; Thoma (Arteries in stumps), Virch. Arch., xciii., also (Atheroma) Virch. Arch., civ., cv., cvi.; Weber, Pitha and Bilroth's Handb., Bd. L, Abth. 1; Cornil et Ranvier,. 2nd ed., 1881, i., 598; Paget, Lect. on surg.; Paul (Ossification) Path, trans., 1886; Coats, (do.) Glasg. Med. Jour., Ap., 1887; Cohn, (do.) Virch. Arch.,cvi.r 378. Aneurysm - BIZOT, Mem. de la Soc. med. d'observation, vol. i., 1836; Hodgson, Lect. on dis. of art. and veins, 1815; Crisp, 1. c.; Broca, Des aneurysmes,. 1856; Koster, Berl. klin. Wochenschr., 1879; Coats and Auld, Brit. Med. Jour., 1893, ii., p. 456, and Journ. of Path. 1895; Gairdner, Allbutt's System of medicine, vol. vi., 1899. Syphilis - Allbutt, St. Geo. Hosp. Rep., iii., iv.; Heubner, Die luetische Erkrankung der Hirnarterien, 1874; Baumgarten, Virch.. Arch., lxxiii.; Huber, do., lxxix.