Evolution of catgut ligatures: the endeavours and success of Joseph Lister and William Macewen.

Lister's product was superior to Macewen's. Lister, however, had started bis experiments ,,'ith ligatures while Macewen was still a medical student and, to begin with at least, Macewen had simply followed bis master's lead. With bis continuing success with carbolic acid and the antiseptic method of wound healing, it must have seemed to Lister that, if he were to sterilize the material then in use with carbolic acid, a permanently buried ligature might be achieved. It would not be absorbed but might remain inert as some bullets and other foreign bodies occasionally did. He chose silk because its smooth surface made it unlikely to cause physical irritation in the tissues. At first he had some success (see Lancel 1869: 451) but he and others had later problems. At best the si.lk ligature would be encapsulated with fibrous tissue but ibis was unusual; more often, sooner or later, it was extruded or had to be removed because of pus formation. There was, however, another strong flexible material, catgut, which had attracted some surgeons but had given disappointing results. When, in the dry sta te, it was imbedded in the tissues it rapidly absorbed fluid and within 24 h or so it had become soft, pulpy and the knot no longer held. Yet it had many advantages. It was readily available and used, among other things, to string a variety of musical instruments because of its resistance to large breaking strains and its relative lack of stretching when under tension. It was cheap; a gross of hanks (i.e. skeins) cost 12 pence (perhaps f4 or so today) and a single hank cost 1 penny. It seemed to have everything required ora ligature except for the excessive rapidity of its absorption. If ibis process could be slowed down to an acceptable 2-3 weeks, a usefulligature material would have been found. Lister visited a catgut manufacturer and was impressed not only by the crudity of catgut preparation but by the beauty of the final producto He is worth quoting: