[Studies on perfecting Polish-made linen threads for surgical use]

Although many varieties of synthetic surgical threads exist there is still much demand for linen threads, due to their good resistance parameters and surgical suitability. In biological studies there is found, yet, a more increased reaction around linen threads than around synthetic ones, but the reaction is smaller than that around silk or catgut threads. The increase in the reaction around linen threads is mainly due to the differences - characteristic of natural polymers - in their chemical composition, high absorbability and coarseness. These adverse properties many be reduced by proper handling of raw thread and proper selection of the preparations put on their surface. This study was the find cut how to refine linen surgical threads by bettering some parameters of raw material and by replacing the preparations used in Poland, consisting mainly of wax and paraffin, with preparations of synthetic polymers of acknowledged suitability for medical use. For the study 12 varieties of flaxen thread, of surgical thickness "0", were used, including 3 groups of raw thread of various twists, 3 groups of cleaned thread, 2 groups of mercerized thread, 4 groups of threads covered with specially prepared preparations on the basis od silicon polymers and polyurethanes. Linen threads by the Ethicon manufacture were used as the basis for comparison. The investigations concerned: --physical and mechanical properties, including tensile strength, friction coefficient, vettability, and evaluation of surface by scanning electron microscope; --biological study in vitro, including evaluation of haemolitic action on human erythrocytes, and toxic action on bull spermatozoa, using water solutions of the studies threads. The water solutions were also studied laboratorily; --biological study in vivo, including evaluation of surgical suitability for muscle implantation, estimation of durability in tissues and macroscopic and microscopic estimate of tissue reaction around the grafts. The threads were implanted into dorsal muscles of rats and into the peritoneal cavity. The results were estimated and the following conclusions were formed: 1. Thread cleaning by continuous extraction in ethyl alcohol only insignificantly improves their properties in comparison with raw material. 2. The optimum twist for flax surgical threads No "0" is 480 twists/m. 3. Mercerization of linen threads for surgical use does not improve their properties. 4. The selected types of silicon polymer and polyurethane preparations, put on raw linen threads, significantly improved their surgical suitability. Biological properties of such threads were better than those in model threads.(ABSTRACT TRUNCATED AT 400 WORDS)