Effect of polyhydroxybutyrate coating on the characteristics of surgical knots in lavsan sutures

Abstract

A comparative study of the characteristics of surgical knots in the initial lavsan thread and sutures with a coating of the biocompatible and biodegradable polymer polyhydroxybutyrate showed that modification did not reduce the holding power, effectiveness, and degree of reliability of the knots. Increasing these characteristics of some knots in modified sutures allows using less complex knots in them and consequently reducing suture consumption and the risk of infection of the surgical wound.The current requirements for suture materials have now increased significantly. In generalizing the information from different sources, they can be formulated as follows: biocompatibility, surface atraumaticity, absence of wicking, good manipulation properties, high strength, ability to reliably hold knots, in many cases resorbability and prophylactic antimicrobial or other effects [1, p. 18]. Of all these requirements, knot reliability is assigned first place by surgeons [2].In continuing our studies [3-5] on creation of surgical sutures with a biocompatible and biodegradable polymer coating of polyhydroxybutyrate (PHB) [6], we investigated the properties of surgical knots in modified lavsan sutures No. 1 and 2 with PHB and PHB + stearic acid coating used as a plasticizer. Stearic acid (SA) is incorporated because crystallizable polymer coating increases the rigidity of the sutures by approximately two times [4].Polyes-PMD lavsan sutures (TU 9393-003-17328911-2004) of metric sizes (MS) 1.5 and 3 (0.19 and 0.34 mm in diameter, respectively) were used as the initial sutures. A pilot industrial sample of PHB of microbiological origin with a molecular weight of ~900 kDa was provided by the Institute of Biochemistry, Russian Academy of Sciences. The coating was applied on the suture from a solution of the polymer in chloroform in the laboratory setup in [4]. The coating content was 6.2±0.3% of the weight of the suture and the stearic acid content was 5% of the weight of the PHB. The properties of the surgical knots were investigated by the method described in [7].Surgical knots consist of several loops bound in a certain way (Table 1). The reliability of surgical knots is a function of many factors, including the chemical nature and textile structure of the suture, the functional properties of its surface, and the type of knot. Knot reliability is to some degree also a function of the length of the ends of the suture cut near the knot: the longer the ends are, the lower the probability that the knot will become untied. At the same time, excessively long ends, especially in internal sutures, increase the probability of suppuration and development of ligature fistulas.Formation of very complicated knots usually does not significantly increase the reliability of the suture but significantly increases consumption of suture material and makes the surgeons job more difficult. After suturing, successfully healing of the wound is directly dependent on the knot reliability. If an inadequate knot is selected, it can spontaneously come unt...

Retained intrauterine sutures for 6 years

“…The surgical suture “Lavsan” is made by twisting of white or green polyester multifilament yarns and characterized by high strength and elasticity, good manipulation properties, and reliable surgeon's knot. [ 5 ]…”

“…found that coating of the initial Lavsan sutures with a biocompatible and biodegradable polymer (polyhydroxybutyrate) did not reduce the holding power and degree of reliability of the knots. [ 5 ]…”