From Big Medical Encyclopedia

MEDIONEKROZ [medionecrosis; lat. (tunica) of media average cover + necrosis; synonym: medionekroz Gzellya — Erdgeyma, a medial degeneration] — the pathological process developing in an average cover of an aorta, arteries of elastic, elastic and muscular and muscular types; contributes to development of aneurisms, including stratifying.

Distinguish laminar and cystous M.

Vpervye laminar M. Gzellem is described in 1928 (O. of Gsell). In 1929 J. Erdheim described laminar and cystous M.'s combination and entered the term «medionekroz».

The m is observed at inborn malformations of cardiovascular system — Marfan's syndrome (see Marfan a syndrome), coarctations of an aorta (see), etc., endocrine diseases, napr, a hypothyroidism (see), inf. diseases, toxic influences, treatment by estrogen (see), pregnancies (see), shock (see), a collapse (see), a stress (see), deficit in an organism of copper, a lathyrism (see) etc.

Microscopically at laminar M. in a wall of an artery reveal the centers of nekrotizirovanny smooth muscle cells. Elastic fibers become straight lines, approach that is caused by a necrosis of smooth foot cells. Shlat-mann and Becker (T. J. M of Schlatmann,

A. E. of Becker, 1977) allocate 3 degrees of laminar M.: the 1st degree — • a focal necrosis in the site making less than 1/3 width of an average cover of a vessel; the 2nd degree — in the site making from 1 / '3 to 2/3;

the 3rd degree — in the site making more than 2/3 width of an average cover of a vessel.

At cystous M. microscopically find various size and a shape of a cavity and a crack, the dividing muscular and elastic elements of an average cover of a vessel. These cavities contain amorphous basphilic main substance, in Krom reveal glikozaminoglikana (see Mucopolysaccharides). Allocate three degrees of cystous M. At the 1st degree small cysts are located in lamellar unit of an average cover of a vessel (lamellar unit consists of two parallel elastic fibrilla with smooth muscle cells, collagenic fibers and amorphous main substance between them). At the 2nd degree of cystous M. the cavity occupies all width of lamellar unit, at the 3rd degree — big cysts occupy more than one lamellar unit.

The m well comes to light at gistol. a research by means of survey colourings, coloring toluidiiovy blue (see), alcian blue, Schiff's reactant (see Schiff a reactant). It is possible to estimate extent of changes of a vascular wall only on sites, in to-rykh all its layers since in the stratified wall there can be disturbances caused by mechanical factors are kept.

See also Aorta, the Aortic aneurysm, Aneurism stratifying. Bibliography: N and to and f about r about in B. I. and

To l e c to and y S. K. Kistovidny an idiopathic necrosis of the interlayer of an aorta (J. Erdheim's Disease), Arkh. patol., t. 43, No. 7, page 76, 1981; Erdheim J. Medionecrosis aortae idiopathica, Arch. path. Anat., v. 273, p. 454, 1929; Hirs t, A. E. a. Gore I. Is cystic medionecrosis the cause of dissecting aortic aneurysm? Circulation, v. 53, p. 915, 1976; To 1 i m a T. o. The morphology of ascending aortic aneurysms, Hum. Path., v. 14, p. 810, 1983; Leonard J. C. a. o. Dissecting aortic aneurysms, clinicopathological study, Quart. J. Med., v. 48, p. 55, 1979; Schlatmann T. J. a «Be-

with to eg And. E. Histologic changes in the normal aging aorta, implications for dissecting aortic aneurysm, Amer. J. Cardiol., v. 39, p. 13, 1977; about N and e, Pathogenesis of dissecting aneurysm of aorta, ibid., p. 21. M. A. Golosovskaya.