Читать книгу Surgery of Exotic Animals - Группа авторов - Страница 59

Like rats, rabbits have been used as a model to evaluate biomaterials and techniques for use in human surgery. Several studies comparing suture materials in the rabbit urogenital tract have been performed. Comparison of polyglactin 910, polyethylene, and nylon in rabbit uteri showed that polyglactin 910 had a lower inflammation score at 24 days, and 80% of samples were absorbed by 80 days with little residual inflammation. The nonabsorbable sutures were present at 80 days and caused a persistent inflammatory response (Gomel et al. 1980). A similar study comparing polyglactin 910, polyglycolic acid, polypropylene, nylon, and chromic gut in rabbit uterine tissue found that polyglactin 910 had the lowest short‐term (16 days) and long‐term (42 days) tissue reaction. Like other studies, the nonabsorbable sutures remained in the tissues and caused a persistent inflammatory response (Beauchamp et al. 1988). Another study showed that there was no difference in histologic reaction or pregnancy rates between polyglactin 910 and polypropylene in microsurgical anastomoses in rabbit oviducts (Scheidel et al. 1986). Comparison of chromic gut, polyglactin 910, polydioxanone, and polyglyconate in rabbit pyeloureterotomies show that chromic gut caused the most severe inflammatory reaction. The reactions of the synthetic absorbable sutures were similar, but there was persistence of suture in 50% and 100% of pyeloureterotomies closed with polydioxanone and polyglyconate 12 weeks following implantation (Wainstein et al. 1997).

A study comparing gut, chromic gut, polyglactin 910, and polypropylene in rabbit bladder tissue found that the gut and chromic gut had the highest inflammation scores followed by polyglactin 910 and polypropylene. Fifteen weeks following implantation, the gut sutures and polyglactin 910 were almost completely absorbed with little residual inflammation compared to polypropylene (Hanke et al. 1994). Another study evaluating suture material in rabbit bladders compared chromic gut, polydioxanone, and polypropylene. Bladders were evaluated for calculi at 15, 30, 60, and 90 days and calculi formed on all sutures. The persistence of the calculi was dependent on the longevity of the suture material (Morris et al. 1986).

The studies performed in rodents and rabbits show that in most cases, chromic gut is more reactive than synthetic absorbable sutures. Nonabsorbable suture materials tend to cause chronic inflammatory responses where absorbable suture materials leave little residual inflammation after they are broken down. These studies and others on domestic species demonstrate the importance of choosing suture material that will retain tensile strength only long enough for the tissues to heal. Any suture that remains after the tissue has healed can lead to granulomas, calculi, or possibly malignant transformation of the tissues.