Page 673 - Carrahers_Polymer_Chemistry,_Eighth_Edition

636 Carraher’s Polymer Chemistry

19.6 SUTURES

Since surgery begun, about 5,000 BC, tying together the surgical site required a stitching material
we now call sutures. Surgery, combat, accidents, and hunting could result in wounds requiring clo-
sure with sutures.
As time progressed, various suture materials were used, essentially all polymeric, and initially
all natural. Early materials included linen strips, grasses, mandibles of pincher ants, silk, animal
hair, and parts of animals, including muscles, tendons, and intestines. The earliest use of so-called
cat gut was by the ancient Greek physician Galen. The eighteenth century brought along the use
of animal hide and silver wire. By the twentieth century, synthetic sutures began to dominate as
sutures of choice. The introduction of polyglactin structures in the 1970s started the transition from
natural to more synthetic adsorbable sutures.
Sutures are the largest group of devices implanted into humans. There is a wide variety of mate-
rials today available, each with known advantages and limitations.
Today, sutures come in a variety of kinds and sizes. The standard sizes of sutures (with diameters
in inches) follow a system set by the United States Pharmacopeia. The scale originally was 0–3 with
zero being the smallest. As the ability to make strong thin sutures increased, smaller suture diam-
eters were indicated by additional zeros, thus a 00 was smaller than 0. Today, suture size is given by
a number representing the diameter ranging in general order from 10 to 1 and then 1/0–12/0 with
1/0 being the largest and 12/0 being the smallest with a diameter smaller than a human hair strain.
A 4/0 corresponds to a 0000-sized suture and a 6/0 corresponds to a 000000 suture. Thus, in the x/0

series, the x corresponds to the number of zeros that reflect suture diameter.
Table 19.1 contains a listing of suture sizes and typical uses.
As expected, smaller sutures of the same material generally exhibit lower tensile strengths and
can break more easily.
Suture size has some correspondence to the tissue being bound together with thinner tissues like
the face requiring thinner sutures. Thinner sutures are also required for facial surgery to limit scar
formation.
A surgeon considers many factors in choosing which suture to use. These considerations include
(a) knot security, (b) tensile strength and tensile strength lifetime, (c) minimal tissue drag and infl am-
mation, (d) handling, (e) size, (f) inhibition of infection, and (g) potential of allergenic reaction.
Other less obvious factors come into play when choosing a suture. For instance, the age and
health of the patient should be considered. An older person in poor health generally requires a
longer time to heal, thus for absorbate sutures, the required degradation time needs to be increased.
Conversely, for an active child, while the degradation time may be less, the suture may be exposed
to more frequent sudden stresses and the body tissues are generally thinner. The presence of immu-

nodeficiency is also an important factor since they are more susceptible to infection. Patients who
have taken steroids, undergone chemotherapy, infected with human immunovirus (HIV) and so on

TABLE 19.1
Suture Sizes and Typical Uses
Size Typical Uses
0 and larger Abdominal wall closure, drain sites, arterial
lines, fascia, orthopaedic uses
2/0 Blood vessels, viscera, fascia
3/0 Trunk, limbs, gut
4/0 Neck, hands, tendons, mucosa
5/0 Face, neck, blood vessels
6/0 Face
7/0 and smaller Microsurgery, ophthalmology

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