aneurysm

(an'u-rizm) [G. aneurysm a, a widening.] A blood-containing tumor connecting directly with the lumen of an artery or formed by a circumscribed enlargement, either axial or lateral, of an artery, ampull'aiy a., sacculated a. a. by anastomo's is, (i) cirsoid a.; (2) aneurysmal varix.* arte"riove'nous a., a blood-containing tumor connecting with both an artery and a vein; when a direct communication between the two ve els exists, without any intervening sac, the condition is called aneurysmal varix; when there is a sac between the two it is called varicose aneurysm, ax'ial a.., one involving the entire circumference of a blood-ve el, cir's oid a., Ligations for Aneurysm: A, Anel's: B, Hunter's; C, Brasdor's; D, Wardrop's; E, Antyllus'. active dilatation-a. consec'utive a., diffuse a. cylin'droid a., tubular a. diffuse' a., one which has enlarged its area and spread to the surrounding ti ues in consequence of rupture of its walls, dilata'tion-a., general enlargement of an artery; it may be active, due to an actual growth and dilatation of a ve el, usually of a, group of smaller arteries {cirsoid a.); or pa ive, a simple stretching of the diseased wall of the aorta' or one of its primary branches, di ect'ing a., an a. formed by the escape of blood, through a crack in the intima, into the wall of the aorta or other large artery, leading to a separation of the coats of the ve el, embol'lc a., an a. resulting from softening of the arterial wall at the site of lodgement of an embolus, endog'enous a., ^i simple a. resulting from dilatation of the diseased coats of an artery, exog'enous a., one due to traumatism, false a., a pulsating swelling caused by rupture of all the coats of an artery, with retention of the escaped blood in a sac formed by the surrounding ti ues, fu's ifonn a.., an elongated spindle-shaped dilatation of an artery, her'nial a., the protrusion of the stretched inner coats of an artery through a wound in the adventitia. lat'eral a., peripheral a. (i). med'ical a., an a. of one of the internal arteries inacce ible to surgical measures, mil'iaiy a., one of a number of minute sacculated or fusiform dilatations of the smaller cerebral arteries, the rupture of which is a frequent cause of apoplexy, periph'eral a., (i) a saclike a. springing from one side of an artery; (2) an a. of one of the smaller branches of an artery. rac'emose a., active dilatation-a. re'nal a.| renal epistaxis.* sac'cular a., a sac-like bulging on one side of an artery, formed of the middle and outer coats, ser'pentine a., dilatation and tortuosity of an artery, seen sometimes affecting the temporal artery in the aged, sponta'neo us a., endogenous a. sur'gical a., an a. of one of the external arteries, which is amenable to surgical treatment, trac'tion a., an aortic a. a umed to be due to the pull of a persistent duct us arteriosus. traumat'ic a., exogenous a. tu'bular a., the uniform dilatation of an artery along a considerable distance, var'icose a., a blood-containing sac, communicating with both an artery and a vein.