sing, _Brit. Med. Jour._ 1900, vol. ii. p. 668.

CHAPTER IV

INJURIES TO THE BLOOD VESSELS

The small calibre of the modern bullet, and its tendency to take a
direct course, naturally favour the occurrence of more or less
uncomplicated wounds of the large vascular trunks, and both the nature
of these wounds and the results which follow them are in some respects
most characteristic.

NATURE OF THE LESIONS

1. _Contusion or laceration without perforation._--(_a_)The vessel may
be struck laterally, the injured portion then forming a part of the
bounding wall of the wound track, or (_b_) one or more layers of the
vessel wall may be destroyed over a limited area. Given primary union,
these conditions are only of importance in so far as subsequent
contraction of the lumen of the vessel may result from implication in
the neighbouring cicatrix. One of the most striking features of the
wounds as a whole was seen in the hair-breadth escapes of the large limb
vessels with no subsequent ill effects, and such injuries were seen in
every situation.

In a certain proportion of wounds in close proximity to large vessels,
however, a diminution of the normal calibre of the arteries was
observed, either shortly after the injury or later in the advanced
stages of cicatrisation. As an example of early obstruction, the
following may be related. A Mauser bullet passed from the inner side of
the thigh across the neck and great trochanter of the femur beneath the
femoral vessels, and probably struck and grooved the bone, since the
aperture of exit was large and irregular, some 3/4 of an inch in
diameter. One week later no pulse was palpable in either anterior or
posterior tibial arteries at the ankle, and pulsation which was strong
in the common femoral artery was very weak in the superficial femoral.
Slight fulness existed in the hollow of Scarpa's triangle, but not
sufficient to make any serious difference in the contour of the two
limbs. No thrill or abnormal murmur was discoverable. There was no
oedema of the limb, which was also normal in temperature. The patient
was kept at rest in the supine position for three weeks, during which
time the tibial pulses gradually returned. Three weeks later he was
invalided home, the pulses, however, still remaining considerably
smaller than normal.

In the advanced stages of cicatrisation narrowing of the lumen of the
trunk vessels was far from uncommon, especially in cases of wounds o