Biomedical subjects

D Lidman

Publications and source records attributed to D Lidman.

23 records · Page 2Linked to original sources

PubMed1984

The morphology and patency of arterial and venous microvascular anastomoses throughout the first post-operative year. A histological study.

End-to-end microvascular suture anastomoses, 40 arterial and 41 venous, from the rabbits carotid artery and posterior facial vein were harvested at 5 different time intervals (1, 2, 3, 6 and 12 months) post surgery and evaluated with light microscopy. A 100% long-term patency was noted both in arteries and veins. Quantitative measurements of the width of the vessel wall components indicated that a statistically significant temporary hypertrophic response occurred in the arterial intima, culminating in the third month when the width of the vessel wall at the anastomotic level almost doubled the normal. After that the width of the vessel wall again declined but it remained thicker than the adjacent vessel wall at one year post surgery. Among the venous anastomoses, however, the wall thickness at the anastomotic level remained thinner than the adjacent vessel wall throughout the evaluation period. The original vessel wall characteristics are not restored at the anastomotic site with intimal hyperplasia compensating for medial necrosis. Despite these events a technically satisfactory microvascular anastomosis should remain patent for years.

Animals↗

PubMed1982

Histopathology of human extremital arteries throughout life. Including measurements of cystolic pressures in ankle and arm.

Specimens from the paired radial, anterior tibial and dorsalis pedis arteries in 30 humans (age 0-82 years) were obtained at autopsy and were assessed histologically. The arterial intima was found to be significantly thickened in the lower extremity in persons older than 15 years. In both arm and leg there was significantly progressive intimal thickening with age. In persons older than 50, the arterial intimal thickening in the leg was sometimes accompanied by medial sclerosis of the Mönckeberg type, whereas the radial arteries were unaffected. The systolic blood pressure was measured simultaneously in radial and posterior tibial arteries in 25 normotensive persons (12 men, 13 women) in supine and in erect position. The ankle pressure was on average 17 mmHg higher than the arm pressure in the supine position. In standing, this difference was increased to 103 mmHg in men and 93 mmHg in women. The corresponding means of absolute systolic pressure at the ankle were, respectively, 238 and 215 mmHg. The rise in the ankle arterial pressure on standing is secondary to the pressure exerted by the hydrostatic column in the arteries between heart and feet level, and thus is dependent on total body height. The intermittent hypertension in the lower extremities in accordance with posture probably is the principal factor for the more pronounced intimal thickening in the leg arteries. This hypothesis and its implications are discussed.

Adolescent↗

PubMed1981

Evaluation of clinical microvascular anastomoses--reasons for failure.

Thrombosis in clinical microvascular anastomoses is attributed to suture errors and utilization of severely damaged recipient arteries. Histopathological specimens from 24 microvascular anastomoses and 77 vessel biopsies from free tissue transfers and replantation cases were analyzed. Suture errors of any note were rare and occurred primarily in replantation cases in which team experience varied and fatigue was common. Recipient artery damage ranged from minimal to severe; clinical analysis confirmed the devastating effect of refractory spasm associated with intramural scarring from previous trauma. Additional studies by microvascular groups are needed to clarify the causes of thrombosis and the healing mechanism of microvascular anastomosis.

Animals↗

PubMed1981

Blood flow and scanning electron microscope study on venous microvascular anastomoses with Nakayamas apparatus and manual suture.

Endothelium repair and blood flow changes after microvascular anastomoses in rabbit neck veins (diameter 1.5-2.5 mm) with either Nakayamas apparatus or manual suture were studied with scanning electron microscope and electromagnetical flowmeter. The healing process, which was very rapid, was examined at varying intervals from the day of surgery to four weeks postoperatively. Complete endothelialization was evident after one week. The blood flow was unimpaired by anastomosis with Nakayama rings, whereas in the suture group reduction in blood flow followed immediately after surgery. This reduction was however transient and blood flow was normalized two hours postoperatively.

Animals↗

PubMed1981

The normal healing process of microvascular anastomoses.

The vessel wall regeneration and the inflammatory response in the rabbit femoral artery and vein the first three months after microvascular end-to-end suture anastomosis was assessed histologically. The initial damage consisted of endothelial loss and partial necrosis of media and adventitia. The luminal surface was reendothelialized and the adventitial layer restored by 20 days, but the necrotized part of the media did not regenerate. Instead, the vessel wall diameter was maintained by an intimal hyperplastic response. At the anastomotic site a characteristic slight dilatation was persistent. Consequently, the vessel wall architecture was not restored to the preoperative state after microvascular anastomosis.

Animals↗