A hernia should always be completely reduced before any operation is
attempted and the size and situation of the external ring definitely
determined. The larger and the longer a hernia has been allowed to go
unreduced the shorter the inguinal canal will be, as the inner margin
of the internal ring is gradually forced toward the median line of the
body, and in very large hernia the external ring is stretched somewhat
outward so that an opening exists directly through the abdominal wall.
This character of hernia is such that three fingers may easily be
pressed directly into the hernial interval and as a rule so much of
the abdominal contents have been outside the abdomen for so long that
the hernia cannot be overcome without decidedly increasing abdominal
pressure. These cases in which hernial contents can be pressed into
the abdomen by force and which markedly increase the intra-abdominal
pressure when reduced are unsuited for any operative treatment which
does not include excision of a quantity of omentum.
The average case.
In the average case the examination of the external ring will not show
a canal so greatly dilated and it may be taken for granted that it has
not been shortened to a considerable extent by the giving of the
internal margin of the internal ring toward the median line. Under
these circumstances the operator may decide that he has a canal of
from two to three inches in length and lying parallel to Poupart's
ligament and slightly above this structure.
The sac of the hernia usually lies above and in front of the cord.
Running closely connected with the cord are the veins which go to make
up the pampiniform plexus. These veins being close to the cord and the
cord itself quite susceptible to pressure it is advisable to pass the
needle along near the roof of the inguinal canal and to attain this
end it is well to locate definitely the external ring and to have a
distinct knowledge of the exact situation of the upper margin of the
ring.
Considerable cellular tissue is found in the inguinal canal so that in
passing the needle through the canal should it meet with considerable
resistance it has no doubt missed the canal and entered some of the
more resistant tissues making up its walls.
The cellular tissue in the canal is to receive the injection of the
operator and it will be his object to facilitate the diffusion of the
various materials injected so that an extensive formation of
connective tissue will be promoted. The plug action of the injection
is not alone to be considered for the operator is then likely to throw
too much into the canal and with the development of the connective
tissue the canal is unduly crowded.
The ill consequences of hyperinjection should not be forgotten. It is
the error to which the beginner is most liable.