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In addition to understanding specific characteristics of available suture materials, it is important to understand tissue healing. Although tissues heal through the same basic phases of wound healing, there are significant differences in the healing times. This affects the amount of time the sutures are required to support the tissue during the healing process. Table 2.1 summarizes tissue healing times and suture absorption profiles.

Compared with other tissues, the bladder heals very quickly and regains normal tensile strength in 14–21 days (Cornell 2012). When choosing a suture material to use for bladder repair, Monocryl, Biosyn, Dexon, or Vicryl may be recommended based on the amount of time these suture materials retain sufficient tensile strength, thus allowing the bladder tissue to heal. Longer‐lasting absorbable sutures such as Maxon or PDS are probably not appropriate for bladder surgery unless delayed healing is anticipated. Nonabsorbable sutures may promote calculus formation. Conversely, sutures that are absorbed very rapidly (e.g. Caprosyn, Vicryl Rapide) probably do not retain sufficient tensile strength long enough and may increase the risk of dehiscence.

The gastrointestinal tract also heals at a relatively rapid rate, with the strength of the repair site approximating the original tissue strength in 10–17 days for the small intestine and up to 30 days for the large intestine (Durdey and Bucknall 1984; Hedlund 2002). The maturation phase in gastrointestinal tract healing occurs between 10 and 180 days after surgery. Polydioxanone, Monocryl, Biosyn, or Maxon provide sufficient tissue support for the gastrointestinal tract to allow for adequate healing.

Healing time for fascia is longer than for the gastrointestinal tract or urinary tract; therefore, fascia requires prolonged tissue support. Twenty days after surgery, the body wall has only regained 20% of its original tensile strength (Cornell 2012). Because fascia has a slower healing time, suture materials that will provide longer support of the tissues (e.g. PDS, Maxon) are recommended. Tissues such as tendons can take six weeks to a year to completely heal and require long‐term support with orthopedic implants or external coaptation in addition to sutures (Montgomery and Fitch 2003). When repairing tissues that take an extended period of time to heal, longer‐lasting sutures such as PDS or Maxon, or nonabsorbable sutures like Prolene or nylon should be used.

In many cases, tissue‐healing times were determined using animal models to assess healing in mammalian tissues. Studies have shown differences in healing times between mammalian species (Cornell 2012), and these will vary significantly from reptile or amphibian tissues. The healing times presented here are to demonstrate the relationship between loss of tensile strength, time to complete absorption, and tissue healing. Veterinarians must consider the specifics of the species and tissues they are operating on to determine the best suture choice.

Table 2.1 Percentage of retained tensile strength following implantation and number of days required for complete absorption for commonly available suture materials.

Suture material	7 d	14 d	21 d	28 d	42 d	Complete absorption (d)
Chromic gut				0		60–90
Polydioxanone (PDS)		70		50	25	180–210
Polyglyconate (Maxon)	80	75	65	50	25	180
Glycomer 631 (Biosyn)		75	40			90–110
Polyglecaprone 25 (Monocryl)	60–70	30–40				90–120
Polyglycolic acid (Dexon)		20				60
Polyglactin 910 (Vicryl)		75	50	25		56–70
Lactomer (Polysorb)		80	30			56–70
Polyglytone 6211 (Caprosyn)	50–60	20–30	0			56
Polyglactin 910 (Vicryl Rapide)	50	0				42
Oral mucosa	X‐‐‐‐X
Skin	X‐‐‐‐‐‐‐‐‐‐‐‐‐‐X
Subcutaneous tissue	X‐‐‐‐‐‐‐‐‐‐‐‐‐‐X
Bladder	X‐‐‐‐‐‐‐‐‐‐‐‐‐X
Gastrointestinal tract	X‐‐‐‐‐‐‐‐‐‐‐X (SI) X‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐X (LI)
Fascia	X‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐X

Ranges in healing times are shown for different tissues. SI, small intestine; LI, large intestine.