[Aneurysm of the ulnar artery in the hypothenar region].

This is a discussion of a rare causative aneurism of the Ulnar Artery in the Hypothenar region. Such aneurisms, according to medical literature are very rare: Smith (1963) collected 35 such cases. According to Smith, Ulnar Aneurism can be of the true or false type. The latter occur following penetrating wounds which damage the arterial wall, and consist of extravasated blood contained in a fibrous capsule. Such aneurism can be micotic, or idiopathic in genesis as well. With chronic trauma, a true aneurism with a fusiform expansion of the arterial wall may be formed. Located within the aneurismatic dilatation are flaky thrombi which could totally occlude the lumen. The author discusses his case of a fifty two year-old chemical worker who sustained trauma eight months prior to the hospitalization. Following the injury, the patient felt pain, and a prickly sensation in the fourth and fifth fingers of his right hand. These symptoms become more pronounced and, with the time the third, fourth, and fifth fingers acquired a pale color. The pain radiated up to the axillary region. A small mass was detected in the hypothenar region immediately distal to the wrist joint. Tinnel's sign was positive. Sensitivity of the palmer aspect of the hypothenar region as well as in the ulnar aspect of the fourth and all of the fifth fingers was impaired. The motor funkcion of the above affected areas remained normal. During the operation, an aneurism of the Ulnar Artery was found in the Canal of Guyon which extended to Arcus Palmaris Superficialis. The aneurism was ligated and resected. The histological finding showed that this was a true aneurysm with a progressive organization of thrombi in one part of its wall. The postoperative course was free of complications. Five months following the operation, the patient felt no pain or prickly sensation. The temperature and color of the area under question had returned to normal.