Thank you for your inquiry.
Unfortunately, I am afraid I am not going to be able to give definitive answers to your questions because there is actually a dearth of information available regarding the issue of suture rejection. The suture you mentioned, Monocryl (poliglecaprone), is a synthetic fast-absorbing suture composed of glycolide and epsilon-caprolactone copolymer. It has low tissue reactivity (see abstract copied below), but clearly can induce at least a temporary inflammatory reaction (same abstract). It is thought to be non-antigenic and non-pyrogenic. During absorption, characteristically it produces only a slight tissue reaction.
However, it is a foreign body, and no matter how non-antigenic a foreign body may be, it can cause an inflammatory response. It is this inflammatory response that is thought to be responsible for suture reactions and rejection. During suture rejections or “spitting,” biopsies have shown classical foreign body reactions with the presence of giant cells.
Unfortunately, it is not known for sure how long reactions to suture can persist, nor has the exact underlying mechanism been explained. If it is an immunologic reaction, it would be a delayed hypersensitivity response (like a contact dermatitis), and clearly a second exposure would be likely to produce a faster and perhaps more severe response. However, I am not aware of nor could I find in the literature any definitive study dealing with the underlying mechanism(s) of suture rejections and, therefore, to my knowledge, all we can do is hypothesize.
Thank you again for your inquiry and we hope this response is helpful to you.
Vet Surg. 1999 Nov-Dec;28(6):466-71.
Tissue reactivity to poliglecaprone 25 in the feline linea alba.
Runk A, Allen SW, Mahaffey EA.
Department of Small Animal Medicine, College of Veterinary Medicine, The University of Georgia, Athens, USA.
Objective: To use poliglecaprone 25 for all ligations and closure in routine feline ovariohysterectomies and evaluate maintenance of tissue approximation and tissue reaction to the suture.
Study Design: Prospective, descriptive study.
Animals: Twenty four female cats.
Methods: Ovariohysterectomies were performed in all cats. Abdominal incisions were inspected on days 1, 3, 7, 14, and 28 for dehiscence and swelling. All cats were euthanatized postoperatively, group 1 on day 7; group 2 on day 14; and group 3 on day 28. The peritoneal cavity was inspected for adhesions and all abdominal incisions were collected en bloc. Each linea alba was histologically evaluated and the inflammatory reaction was characterized.
Results: Dehiscence did not occur in any of the 24 cats. The incisional swelling on day 1 was significantly smaller than on day 7, and the swelling on day 14 was significantly smaller than on days 1, 3, and 7 (P < .05). Intra-abdominal adhesions were found in all groups with the greatest number associated with the peritoneum at the incision site. Tissue reactions in group 1 were pyogranulomatous or fibromononuclear, group 2 were granulomatous or fibromononuclear, and group 3 were pyogranulomatous, granulomatous, fibromononuclear or fibrous. Eosinophilic infiltration was seen in 3 of the 8 cats in group 1.
Conclusions: Incisional swelling and inflammatory reactions seen with poliglecaprone 25 were consistent with those anticipated after implantation of suture in a surgically created wound.
Clinical Relevance: Poliglecaprone 25 appears to be an acceptable suture for use in feline ovariohysterectomy. It causes a relatively short-lived inflammatory response.
Phil Lieberman, M.D.