Author/Editor		Geršak, B
Title		Vpliv tlaka žilne prijemalke na kontraktilno in relaksacijsko sposobnost torakalne aorte podgan
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1994
Volume		str. 55
Language		slo
Abstract		In cardiovascular surgery a long term patency of vascular anastomoses is obligatory and also a measure of success. During the last few years more and more interest is put on details of operating technique, which could lead to relatively better long term pooperative results. One of such details is the effect of direct surgical trauma on the small caliber vessels, especially arterial grafts used in coronary surgery. Here the vessel wall is the object and the most important factor, which could easily be damaged by inappropriate surgical technique or by surgical clamping, since every surgical procedure with exposed endothelial layers needs the occlusion of blood flow through this area. We used a novel equipment for measuring the direct tip pressure P of a clamp arm on the vessel wall to test contraction relaxation reactions of rat thoracic aortas to various clamping pressures. A minimal clamping pressure (Pm) which must stop the blood flow and prevent the sliding of cut vessel ends out of clamp arms was defined to be three times of a vascular systolic pressure. A measuring system for in-vivo measurements of forces applied with various clamps on the vessel walls and to test the forces of commonly used surgical clamps was defined. Clamping forces of two clamps commonly used in cardiovascular microsurgery were used in the experiment: clamp A had the tip pressure P approximately equal to Pm (P = O.6O N/mm2), clamp B had the tip pressure almost nine times greater than Pm (P = 5.16 N/mm2). Wistar albino rats, with mass 328 +- 19 g were intubated, artificially ventilated and anesthess sia was obtained with an intraperitoneal injection of pentobarbitalnatrium of 0.1 mg/kg. The thoracic aorta was dissected through the left fourth intercostal space. Prior to clamping, 5000 IU/kg of the heparine was administered intravenously. After 15 minutes of occlusion, the animals were sacrificed and three vascular rings (2 mm wide) were excised.(trunc.)
Descriptors		AORTA, THORACIC MUSCLE, SMOOTH, VASCULAR POTASSIUM CHLORIDE CARBACHOL RATS ANIMALS, LABORATORY VASOMOTOR SYSTEM NOREPINEPHRINE MICROSCOPY, ELECTRON, SCANNING DISSECTION PRESSURE