Alexis Thomson and Alexander Miles - Manual of Surgery

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The coughing up of blood from the lungs is known as _haemoptysis_;
vomiting of blood from the stomach, as _haematemesis_; the passage of
black-coloured stools due to the presence of blood altered by digestion,
as _melaena_; and the passage of bloody urine, as _haematuria_.

Haemorrhage is known as arterial, venous, or capillary, according to the
nature of the vessel from which it takes place.

In _arterial_ haemorrhage the blood is bright red in colour, and escapes
from the cardiac end of the divided vessel in pulsating jets
synchronously with the systole of the heart. In vascular parts--for
example the face--both ends of a divided artery bleed freely. The blood
flowing from an artery may be dark in colour if the respiration is
impeded. When the heart's action is weak and the blood tension low the
flow may appear to be continuous and not in jets. The blood from a
divided artery at the bottom of a deep wound, escapes on the surface in
a steady flow.

_Venous_ bleeding is not pulsatile, but occurs in a continuous stream,
which, although both ends of the vessel may bleed, is more copious from
the distal end. The blood is dark red under ordinary conditions, but may
be purplish, or even black, if the respiration is interfered with. When
one of the large veins in the neck is wounded, the effects of
respiration produce a rise and fall in the stream which may resemble
arterial pulsation.

In _capillary_ haemorrhage, red blood escapes from numerous points on the
surface of the wound in a steady ooze. This form of bleeding is serious
in those who are the subjects of haemophilia.

INJURIES OF ARTERIES

The following description of the injuries of arteries refers to the
larger, named trunks. The injuries of smaller, unnamed vessels are
included in the consideration of wounds and contusions.

#Contusion.#--An artery may be contused by a blow or crush, or by the
oblique impact of a bullet. The bruising of the vessel wall, especially
if it is diseased, may result in the formation of a thrombus which
occludes the lumen temporarily or even permanently, and in rare cases
may lead to gangrene of the limb beyond.

#Subcutaneous Rupture.#--An artery may be ruptured subcutaneously by a
blow or crush, or by a displaced fragment of bone. This injury has been
produced also during attempts to reduce dislocations, especially those
of old standing at the shoulder. It is most liable to occur when the
vessels are diseased. The rupture may be incomplete or complete.

_Incomplete Subcutaneous Rupture._--In the majority of cases the rupture
is incomplete--the inner and middle coats being torn, while the outer
remains intact. The middle coat contracts and retracts, and the
internal, because of its elasticity, curls up in the interior of the
vessel, forming a valvular obstruction to the blood-flow. In most cases
this results in the formation of a thrombus which occludes the vessel.
In some cases the blood-pressure gradually distends the injured segment
of the vessel wall and leads to the formation of an aneurysm.

The pulsation in the vessels beyond the seat of rupture is arrested--for
a time at least--owing to the occlusion of the vessel, and the limb
becomes cold and powerless. The pulsation seldom returns within five or
six weeks of the injury, if indeed it is not permanently arrested, but,
as a rule, a collateral circulation is rapidly established, sufficient
to nourish the parts beyond. If the pulsation returns within a week of
the injury, the presumption is that the occlusion was due to pressure
from without--for example, by haemorrhage into the sheath or the pressure
of a fragment of bone.

_Complete Subcutaneous Rupture._--When the rupture is complete, all the
coats of the vessel are torn and the blood escapes into the surrounding
tissues. If the original injury is attended with much shock, the
bleeding may not take place until the period of reaction. Rupture of the
popliteal artery in association with fracture of the femur, or of the
axillary or brachial artery with fracture of the humerus or dislocation
of the shoulder, are familiar examples of this injury.

Like incomplete rupture, this lesion is accompanied by loss of pulsation
and power, and by coldness of the limb beyond; a tense and excessively
painful swelling rapidly appears in the region of the injury, and, where
the cellular tissue is loose, may attain a considerable size. The
pressure of the effused blood occludes the veins and leads to congestion
and oedema of the limb beyond. The interference with the circulation, and
the damage to the tissues, may be so great that gangrene ensues.

_Treatment._--When an artery has been contused or ruptured, the limb
must be placed in the most favourable condition for restoration of the
circulation. The skin is disinfected and the limb wrapped in cotton wool
to conserve its heat, and elevated to such an extent as to promote the
venous return without at the same time interfering with the inflow of
blood. A careful watch must be kept on the state of nutrition of the
limb, lest gangrene occurs.

If no complications supervene, the swelling subsides, and recovery may
be complete in six or eight weeks. If the extravasation is great and the
skin threatens to give way, or if the vitality of the limb is seriously
endangered, it is advisable to expose the injured vessel, and, after
clearing away the clots, to attempt to suture the rent in the artery,
or, if torn across, to join the ends after paring the bruised edges. If
this is impracticable, a ligature is applied above and below the
rupture. If gangrene ensues, amputation must be performed.

These descriptions apply to the larger arteries of the extremities. A
good illustration of subcutaneous rupture of the arteries of the head is
afforded by the tearing of the middle meningeal artery caused by the
application of blunt violence to the skull; and of the arteries of the
trunk--caused by the tearing of the renal artery in rupture of the
kidney.

#Open Wounds of Arteries--Laceration.#--Laceration of large arteries is
a common complication of machinery and railway accidents. The violence
being usually of a tearing, twisting, or crushing nature, such injuries
are seldom associated with much haemorrhage, as torn or crushed vessels
quickly become occluded by contraction and retraction of their coats and
by the formation of a clot. A whole limb even may be avulsed from the
body with comparatively little loss of blood. The risk in such cases is
secondary haemorrhage resulting from pyogenic infection.

The _treatment_ is that applicable to all wounds, with, in addition, the
ligation of the lacerated vessels.

#Punctured wounds# of blood vessels may result from stabs, or they may
be accidentally inflicted in the course of an operation.

The division of the coats of the vessel being incomplete, the natural
haemostasis that results from curling up of the intima and contraction of
the media, fails to take place, and bleeding goes on into the
surrounding tissues, and externally. If the sheath of the vessel is not
widely damaged, the gradually increasing tension of the extravasated
blood retained within it may ultimately arrest the haemorrhage. A clot
then forms between the lips of the wound in the vessel wall and projects
for a short distance into the lumen, without, however, materially
interfering with the flow through the vessel. The organisation of this
clot results in the healing of the wound in the vessel wall.

In other cases the blood escapes beyond the sheath and collects in the
surrounding tissues, and a traumatic aneurysm results. Secondary
haemorrhage may occur if the wound becomes infected.

The _treatment_ consists in enlarging the external wound to permit of
the damaged vessel being ligated above and below the puncture. In some
cases it may be possible to suture the opening in the vessel wall. When
circumstances prevent these measures being taken, the bleeding may be
arrested by making firm pressure over the wound with a pad; but this
procedure is liable to be followed by the formation of an aneurysm.

_Minute puncture of arteries_ such as frequently occur in the hypodermic
administration of drugs and in the use of exploring needles, are not
attended with any escape of blood, chiefly because of the elastic recoil
of the arterial wall; a tiny thrombus of platelets and thrombus forms at
the point where the intima is punctured.

#Incised Wounds.#--We here refer only to such incised wounds as partly
divide the vessel wall.

Longitudinal wounds show little tendency to gape, and are therefore not
attended with much bleeding. They usually heal rapidly, but, like
punctured wounds, are liable to be followed by the formation of an
aneurysm.

When, however, the incision in the vessel wall is oblique or transverse,
the retraction of the muscular coat causes the opening to gape, with the
result that there is haemorrhage, which, even in comparatively small
arteries, may be so profuse as to prove dangerous. When the associated
wound in the soft parts is valvular the haemorrhage is arrested and an
aneurysm may develop.

When a large arterial trunk, such as the external iliac, the femoral,
the common carotid, the brachial, or the popliteal, has been partly
divided, for example, in the course of an operation, the opening should
be closed with sutures--_arteriorrhaphy_. The circulation being
controlled by a tourniquet, or the artery itself occluded by a clamp,
fine silk or catgut stitches are passed through the outer and middle
coats after the method of Lembert, a fine, round needle being employed.
The sheath of the vessel or an adjacent fascia should be stitched
over the line of suture in the vessel wall. If infection be excluded,
there is little risk of thrombosis or secondary haemorrhage; and even if
thrombosis should develop at the point of suture, the artery is
obstructed gradually, and the establishment of a collateral circulation
takes place better than after ligation. In the case of smaller trunks,
or when suture is impracticable, the artery should be tied above and
below the opening, and divided between the ligatures.

#Gunshot Wounds of Blood Vessels.#--In the majority of cases injuries of
large vessels are associated with an external wound; the profusion of
the bleeding indicates the size of the damaged vessel, and the colour of
the blood and the nature of the flow denote whether an artery or a vein
is implicated.

When an artery is wounded a firm _haematoma_ may form, with an expansile
pulsation and a palpable thrill--whether such a haematoma remains
circumscribed or becomes diffuse depends upon the density or laxity of
the tissues around it. In course of time a _traumatic arterial aneurysm_
may develop from such a haematoma.

When an artery and its companion vein are injured simultaneously an
_arterio-venous aneurysm_ (p. 310) may develop. This frequently takes
place without the formation of a haematoma as the arterial blood finds
its way into the vein and so does not escape into the tissues. Even if a
haematoma forms it seldom assumes a great size. In time a swelling is
recognised, with a palpable thrill and a systolic bruit, loudest at the
level of the communication and accompanied by a continuous venous hum.

If leakage occurs into the tissues, the extravasated blood may occlude
the vein by pressure, and the symptoms of arterial aneurysm replace
those of the arterio-venous form, the systolic bruit persisting, while
the venous hum disappears.

_Gangrene_ may ensue if the blood supply is seriously interfered with,
or the signs of _ischaemia_ may develop; the muscles lose their
elasticity, become hard and paralysed, and anaesthesia of the "glove" or
"stocking" type, with other alterations of sensation ensue. Apart from
ischaemia, _reflex paralysis_ of motion and sensation of a transient kind
may follow injury of a large vessel.

_Treatment_ is carried out on the same lines as for similar injuries due
to other causes.

INJURIES OF VEINS

Veins are subject to the same forms of injury as arteries, and the
results are alike in both, such variations as occur being dependent
partly on the difference in their anatomical structure, and partly on
the conditions of the circulation through them.

#Subcutaneous rupture# of veins occur most frequently in association
with fractures and in the reduction of dislocations. The veins most
commonly ruptured are the popliteal, the axillary, the femoral, and the
subclavian. On account of the smaller amount of elastic and muscular
tissue in the wall of a vein, the contraction and retraction of its
walls are less than in an artery, and so bleeding may continue for a
longer period. On the other hand, owing to the lower blood-pressure the
outflow goes on more slowly, and the gradually increasing pressure
produced by the extravasated blood is usually sufficient to arrest the
haemorrhage before it becomes serious. As an aid in diagnosing the source
of the bleeding, it should be remembered that the rupture of a vein does
not affect the pulsation in the limb beyond. The risks are practically
the same as when an artery is ruptured, excepting that of aneurysm, and
the treatment is carried out on the same lines, but it is seldom
necessary to operate for the purpose of applying a ligature to the
injured vein.

#Wounds# of veins--punctured and incised--frequently occur in the course
of operations; for example, in the removal of tumours or diseased glands
from the neck, the axilla, or the groin. They are also met with as a
result of accidental stabs and of suicidal or homicidal injuries. The
haemorrhage from a large vein so damaged is usually profuse, but it is
more readily controlled by external pressure than that from an artery.
When a vein is merely punctured, the bleeding may be arrested by
pressure with a pad of gauze, or by a lateral ligature--that is, picking
up the margins of the rent in the wall and securing them with a
ligature without occluding the lumen. In the large veins, such as the
internal jugular, the femoral, or the axillary, it is usually possible
to suture the opening in the wall. This does not necessarily result in
thrombosis in the vessel, or in obliteration of its lumen.

When an _artery and vein are simultaneously wounded_, the features
peculiar to each are present in greater or less degree. In the limbs
gangrene may ensue, especially if the wound is infected. Punctured and
gun-shot wounds implicating both artery and vein are liable to be
followed by the development of arterio-venous aneurysm.

#Entrance of Air into Veins--Air Embolism.#--This serious, though
fortunately rare, accident is apt to occur in the course of operations
in the region of the thorax, neck, or axilla, if a large vein is opened
and fails to collapse on account of the rigidity of its walls, its
incorporation in a dense fascia, or from traction being made upon it. If
the wound in a vein is thus held open, the negative pressure during
inspiration sucks air into the right side of the heart. This is
accompanied by a hissing or gurgling sound, and with the next expiration
some frothy blood escapes from the wound. The patient instantly becomes
pale, the pupils dilate, respiration becomes laboured, and although the
heart may continue to beat forcibly, the peripheral pulse is weak, and
may even be imperceptible. On auscultating the heart, a churning sound
may be heard. Death may result in a few minutes; or the heart may slowly
regain its power and recovery take place.

_Prevention._--In operations in the "dangerous area"--as the region of
the root of the neck is called in this connection--care must be taken
not to cut or divide any vein before it has been secured by forceps, and
to apply ligatures securely and at once. Deep wounds in this region
should be kept filled with normal salt solution. Immediately a cut is
recognised in a vein, a finger should be placed over the vessel on the
cardiac side of the wound, and kept there until the opening is secured.

_Treatment._--Little can be done after the air has actually entered the
vein beyond endeavouring to maintain the heart's action by hypodermic
injections of ether or strychnin and the application of mustard or hot
cloths over the chest. The head at the same time should be lowered to
prevent syncope. Attempts to withdraw the air by suction, and the
employment of artificial respiration, have proved futile, and are, by
some, considered dangerous. In a desperate case massage of the heart
might be tried.

THE NATURAL ARREST OF HAEMORRHAGE AND THE REPAIR OF BLOOD
VESSELS

#Primary Haemorrhage.#--The term primary haemorrhage is applied to the
bleeding which follows immediately on the wounding of a blood vessel.
The natural process by which such haemorrhage is arrested varies with the
character of the wound in the vessel and may be modified by accidental
circumstances.

(a) _Repair of completely divided Artery._--When an artery is
_completely_ divided, the circular fibres of the muscular coat contract,
so that the lumen of the cut ends is diminished, and at the same time
each segment retracts within its sheath in virtue of the recoil of the
elastic elements in its walls, the tunica intima curls up in the
interior of the vessel, and the tunica externa collapses over the cut
ends. The blood that escapes from the injured vessel fills the
interstices of the tissues, and, coagulating, forms a clot which
temporarily arrests the bleeding. That part of the clot which lies
between the divided ends of the vessel and in the cellular tissue
outside, is known as the _external clot_, while the portion which
projects into the lumen of the vessel is known as the _internal clot_,
and it usually extends as far as the nearest collateral branch. These
processes constitute what is known as the _temporary arrest of
haemorrhage_, which, it will be observed, is effected by the contraction
and retraction of the divided artery and by clotting.

The _permanent arrest_ takes place by the transformation of the clot
into scar tissue. The internal clot plays the most important part in the
process; it becomes invaded by leucocytes and proliferating endothelial
and connective-tissue cells, and new blood vessels permeate the mass,
which is thus converted into granulation tissue. This is ultimately
replaced by fibrous tissue, which permanently occludes the end of the
vessel. Concurrently and by the same process the external clot is
converted into scar tissue.

If a divided artery is _ligated at its cut end_, the tension of the
ligature is usually sufficient to rupture the inner and middle coats,
which curl up within the lumen, the outer coat alone being held in the
grasp of the ligature. An internal clot forms and, becoming organised,
permanently occludes the vessel as above described. The ligature and the
small portion of vessel beyond it are subsequently absorbed.

In course of time the collateral branches of the vessel above and below
the level of section enlarge and their inter-communication becomes more
free, so that even when large trunks have been divided the vascular
supply of the parts beyond may be completely restored. This is known as
the development of the _collateral circulation_.

_Imperfect Collateral Circulation._--While the development of the
collateral circulation after the ligation or obstruction from other
cause of a main arterial trunk may be sufficient to prevent gangrene of
the limb, it may be insufficient for its adequate nourishment; it may be
cold, bluish in colour, and there may be necrosis of the skin over bony
points; this is notably the case in the lower extremity after ligation
of the femoral or popliteal artery, when patches of skin may die over
the prominence of the heel, the balls of the toes, the projecting base
of the fifth metatarsal and the external malleolus.

If, during the period of reaction, the blood-pressure rises
considerably, the occluding clot at the divided end of the vessel may be
washed away or the ligature displaced, permitting of fresh bleeding
taking place--_reactionary_ or _intermediary haemorrhage_ (p. 272).

In the event of the wound becoming infected with pyogenic organisms, the
occluding blood-clot or the young fibrous tissue may become
disintegrated in the suppurative process, and the bleeding start
afresh--_secondary haemorrhage_ (p. 273).

(b) If an artery is only _partly cut across_, the divided fibres of
the tunica muscularis contract and those of the tunica externa retract,
with the result that a more or less circular hole is formed in the wall
of the vessel, from which free bleeding takes place, as the conditions
are unfavourable for the formation of an occluding clot. Even if a clot
does form, when the blood-pressure rises it is readily displaced,
leading to reactionary haemorrhage. Should the wound become infected,
secondary haemorrhage is specially liable to occur. A further risk
attends this form of injury, in that the intra-vascular tension may in
time lead to gradual stretching of the scar tissue which closes the gap
in the vessel wall, with the result that a localised dilatation or
diverticulum forms, constituting a _traumatic aneurysm_.

(c) When the injury merely takes the form of a _puncture_ or _small
incision_ a blood-clot forms between the edges, becomes organised, and
is converted into cicatricial tissue which seals the aperture. Such
wounds may also be followed by reactionary or secondary haemorrhage, or
later by the formation of a traumatic aneurysm.

_Conditions which influence the Natural Arrest of Haemorrhage._--The
natural arrest of bleeding is favoured by tearing or crushing of the
vessel walls, owing to the contraction and retraction of the coats and
the tendency of blood to coagulate when in contact with damaged tissue.
Hence the primary haemorrhage following lacerated wounds is seldom
copious. The occurrence of syncope or of profound shock also helps to
stop bleeding by reducing the force of the heart's action.

On the other hand, there are conditions which retard the natural arrest.
When, for example, a vessel is only partly divided, the contraction and
retraction of the muscular coat, instead of diminishing the calibre of
the artery, causes the wound in the vessel to gape; by completing the
division of the vessel under these circumstances the bleeding can often
be arrested. In certain situations, also, the arteries are so intimately
connected with their sheaths, that when cut across they were unable to
retract and contract--for example, in the scalp, in the penis, and in
bones--and copious bleeding may take place from comparatively small
vessels. This inability of the vessels to contract and retract is met
with also in inflamed and oedematous parts and in scar tissue. Arteries
divided in the substance of a muscle also sometimes bleed unduly. Any
increase in the force of the heart's action, such as may result from
exertion, excitement, or over-stimulation, also interferes with the
natural arrest. Lastly, in bleeders, there are conditions which
interfere with the natural arrest of haemorrhage.

#Repair of a Vessel ligated in its Continuity.#--When a ligature is
applied to an artery it should be pulled sufficiently tight to occlude
the lumen without causing rupture of its coats. It often happens,
however, that the compression causes rupture of the inner and middle
coats, so that only the outer coat remains in the grasp of the ligature.
While this weakens the wall of the vessel, it has the advantage of
hastening coagulation, by bringing the blood into contact with damaged
tissue. Whether the inner and middle coats are ruptured or not, blood
coagulates both above and below the ligature, the proximal clot being
longer and broader than that on the distal side. In small arteries these
clots extend as far as the nearest collateral branch, but in the larger
trunks their length varies. The permanent occlusion of those portions of
the vessel occupied by clot is brought about by the formation of
granulation tissue, and its replacement by cicatricial tissue, so that
the occluded segment of the vessel is represented by a fibrous cord. In
this process the coagulum only plays a passive role by forming a
scaffolding on which the granulation tissue is built up. The ligature
surrounding the vessel, and the elements of the clot, are ultimately
absorbed.

#Repair of Veins.#--The process of repair in veins is the same as that
in arteries, but the thrombosed area may become canalised and the
circulation through the vessel be re-established.

HAEMORRHAGE IN SURGICAL OPERATIONS

The management of the haemorrhage which accompanies an operation includes
(a) preventive measures, and (b) the arrest of the bleeding.

#Prevention of Haemorrhage.#--Whenever possible, haemorrhage should be
controlled by _digital compression_ of the main artery supplying the
limb rather than by a tourniquet. If efficiently applied compression
reduces the immediate loss of blood to a minimum, and the bleeding from
small vessels that follows the removal of the tourniquet is avoided.
Further, the pressure of a tourniquet has been shown to be a material
factor in producing shock.