Page 73 - Virtual Vascular Vol 15

Size

Suture sizes are designated by the USP (United States
Pharmacopeia) system. Suture sizes run from sizes 11-0 to
7. From 0 to 11-0, an addition of a zero signifies a further
decrease in diameter. “6-0” refers to a size of #000000.
The smallest suture available now is the 11-0 suture. It is
0.01mm in diameter (for your reference, human hair has
an average diameter of 0.075mm!), and it is mostly used in
ophthalmic surgeries. Some smaller sized sutures are dyed
to enhance visibility. The larger the suture diameter, the
relatively stronger it is.

When choosing a suture size, it is important to choose the
smallest size of suture that can hold both ends of tissue
together without it breaking, and without it being too
small that it would “cheese-wire” cut through the tissue.

Needle

Needles are used to guide a suture into tissue with
minimal trauma. Different types of needles include
- Round bodied needles, used in friable tissues such as
intestinal and vascular anastomosis, muscle and
peritoneum.
- Cutting needles. A conventional cutting needle has a
triangular point with the cutting edge on the inner
curvature, while a reverse cutting needle has the
cutting edge on the outer curvature. They are used in
skin, subcutaneous, or fibrous tissues.

Different needle curvatures are also made to address
different needs. Straight cutting needles are available for
suturing of easily accessible tissue allowing direct finger
manipulation. Curvatures are available in 1/4, 1/8, 3/8, ½
and 5/8 circle. J shaped needles are also available. The
deeper the tissue, the larger the circle arc required.

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