Suture

In surgery, a suture is the strand of material used to close wounds or to join tissues, and also the stitch made with it; to suture means to sew tissue together. Sutures keep cut edges lined up until healing gives the tissue enough strength of its own. Surgeons also use them to tie off bleeding vessels and to join hollow structures such as bowel or arteries.

Suture materials are grouped in several ways. Absorbable sutures, such as polyglactin and polydioxanone, are gradually broken down by the body, mostly by hydrolysis, and suit deep layers where removal would require another procedure. Nonabsorbable sutures, such as nylon, polypropylene and silk, keep their strength far longer and are used for skin stitches that are removed later or for tissues needing permanent support. Natural materials such as silk and surgical gut provoke more inflammation than synthetic ones. A single smooth strand (monofilament) passes easily and gives bacteria fewer hiding places, while a braided strand is easier to handle and knot. Thickness follows a numbered scale in which more zeros mean a finer thread, so 6-0 is finer than 3-0.

In anatomy, a suture is also a fixed, fibrous joint between bones of the skull, such as the coronal or sagittal suture.