Alexis Thomson and Alexander Miles - Manual of Surgery

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When the ulcer has assumed the characters of a healing sore, skin-grafts
may be applied to hasten cicatrisation.

_Ulcers in a callous condition_ call for treatment in three
directions--(1) The infective element must be eliminated. When the ulcer
is foul, relays of charcoal poultices (three parts of linseed meal to
one of charcoal), maintained for thirty-six to forty-eight hours, are
useful as a preliminary step. The base of the ulcer and the thickened
edges should then be freely scraped with a sharp spoon, and the
resulting raw surface sponged over with undiluted carbolic acid or
iodine, after which an antiseptic dressing is applied, and changed daily
till healthy granulations appear. (2) The venous return must be
facilitated by elevation of the limb and massage. (3) The induration of
the surrounding parts must be got rid of before contraction of the sore
is possible. For this purpose the free application of blisters, as first
recommended by Syme, leaves little to be desired. Liquor epispasticus
painted over the parts, or a large fly-blister (emplastrum cantharidis)
applied all round the ulcer, speedily disperses the inflammatory
products which cause the induration. The use of elastic pressure or of
strapping, of hot-air baths, or the making of multiple incisions in the
skin around the ulcer, fulfils the same object.

As soon as the ulcer assumes the characters of a healing sore, it should
be covered with skin-grafts, which furnish a much better cicatrix than
that which forms when the ulcer is allowed to heal without such aid.

A more radical method of treatment consists in excising the whole
ulcer, including its edges and about a quarter of an inch of the
surrounding tissue, as well as the underlying fibrous tissue, and
grafting the raw surface.

_Ambulatory Treatment._--When the circumstances of the patient forbid
his lying up in bed, the healing of the ulcer is much delayed. He should
be instructed to take every possible opportunity of placing the limb in
an elevated position, and must constantly wear a firm bandage of
_elastic webbing_. This webbing is porous and admits of evaporation of
the skin and wound secretions--an advantage it has over Martin's rubber
bandage. The bandage should extend from the toes to well above the knee,
and should always be applied while the patient is in the recumbent
position with the leg elevated, preferably before getting out of bed in
the morning. Additional support is given to the veins if the bandage is
applied as a figure of eight.

We have found the following method satisfactory in out-patient
practice. The patient lying on a couch, the limb is raised about
eighteen inches and kept in this position for five minutes--till the
excess of blood has left it. With the limb still raised, the ulcer with
the surrounding skin is covered with a layer, about half an inch thick,
of finely powdered boracic acid, and the leg, from foot to knee,
excluding the sole, is enveloped in a thick layer of wood-wool wadding.
This is held in position by ordinary cotton bandages, painted over with
liquid starch; while the starch is drying the limb is kept elevated.
With this appliance the patient may continue to work, and the dressing
does not require to be changed oftener than once in three or four weeks
(W. G. Richardson).

When an ulcer becomes acutely _inflamed_ as a result of superadded
infection, antiseptic measures are employed to overcome the infection,
and ichthyol or other soothing applications may be used to allay the
pain.

The _phagedaenic ulcer_ calls for more energetic means of disinfection;
the whole of the affected surface is touched with the actual cautery at
a white heat, or is painted with pure carbolic acid. Relays of charcoal
poultices are then applied until the spread of the disease is arrested.

For the _irritable ulcer_ the most satisfactory treatment is complete
excision and subsequent skin-grafting.

CHAPTER VI

GANGRENE

Definition--Types: _Dry_, _Moist_--Varieties--Gangrene primarily due to
interference with circulation: _Senile gangrene_; _Embolic
gangrene_; _Gangrene following ligation of arteries_; _Gangrene
from mechanical causes_; _Gangrene from heat, chemical agents, and
cold_; _Diabetic gangrene_; _Gangrene associated with spasm of
blood vessels_; _Raynaud's disease_; _Angio-sclerotic gangrene_;
_Gangrene from ergot_. Bacterial varieties of gangrene.
_Pathology_--clinical varieties--_Acute infective gangrene_;
_Malignant oedema_; _Acute emphysematous_ or _gas gangrene_;
_Cancrum oris_, _etc_. Bed-sores: _Acute_; _chronic_.

Gangrene or mortification is the process by which a portion of tissue
dies _en masse_, as distinguished from the molecular or cellular death
which constitutes ulceration. The dead portion is known as a _slough_.

In this chapter we shall confine our attention to the process as it
affects the limbs and superficial parts, leaving gangrene of the viscera
to be described in regional surgery.

TYPES OF GANGRENE

Two distinct types of gangrene are met with, which, from their most
obvious point of difference, are known respectively as _dry_ and
_moist_, and there are several clinical varieties of each type.

Speaking generally, it may be said that dry gangrene is essentially due
to a simple _interference with the blood supply_ of a part; while the
main factor in the production of moist gangrene is _bacterial
infection_.

The cardinal signs of gangrene are: change in the colour of the part,
coldness, loss of sensation and motor power, and, lastly, loss of
pulsation in the arteries.

#Dry Gangrene# or #Mummification# is a comparatively slow form of local
death due, as a rule, to a diminution in the arterial blood supply of
the affected part, resulting from such causes as the gradual narrowing
of the lumen of the arteries by disease of their coats, or the blocking
of the main vessel by an embolus.

As the fluids in the tissues are lost by evaporation the part becomes
dry and shrivelled, and as the skin is usually intact, infection does
not take place, or if it does, the want of moisture renders the part an
unsuitable soil, and the organisms do not readily find a footing. Any
spread of the process that may take place is chiefly influenced by the
anatomical distribution of the blocked arteries, and is arrested as soon
as it reaches an area rich in anastomotic vessels. The dead portion is
then cast off, the irritation resulting from the contact of the dead
with the still living tissue inducing the formation of granulations on
the proximal side of the junction, and these by slowly eating into the
dead portion produce a furrow--the _line of demarcation_--which
gradually deepens until complete separation is effected. As the muscles
and bones have a richer blood supply than the integument, the death of
skin and subcutaneous tissues extends higher than that of muscles and
bone, with the result that the stump left after spontaneous separation
is conical, the end of the bone projecting beyond the soft parts.

_Clinical Features._--The part undergoing mortification becomes colder
than normal, the temperature falling to that of the surrounding
atmosphere. In many instances, but not in all, the onset of the process
is accompanied by severe neuralgic pain in the part, probably due to
anaemia of the nerves, to neuritis, or to the irritation of the exposed
axis cylinders by the dead and dying tissues around them. This pain soon
ceases and gives place to a complete loss of sensation. The dead part
becomes dry, horny, shrivelled, and semi-transparent--at first of a dark
brown, but finally of a black colour, from the dissemination of blood
pigment throughout the tissues. There is no putrefaction, and therefore
no putrid odour; and the condition being non-infective, there is not
necessarily any constitutional disturbance. In itself, therefore, dry
gangrene does not involve immediate risk to life; the danger lies in the
fact that the breach of surface at the line of demarcation furnishes a
possible means of entrance for bacteria, which may lead to infective
complications.

#Moist Gangrene# is an acute process, the dead part retaining its fluids
and so affording a favourable soil for the development of bacteria. The
action of the organisms and their toxins on the adjacent tissues leads
to a rapid and wide spread of the process. The skin becomes moist and
macerated, and bullae, containing dark-coloured fluid or gases, form
under the epidermis. The putrefactive gases evolved cause the skin to
become emphysematous and crepitant and produce an offensive odour. The
tissues assume a greenish-black colour from the formation in them of a
sulphide of iron resulting from decomposition of the blood pigment.
Under certain conditions the dead part may undergo changes resembling
more closely those of ordinary post-mortem decomposition. Owing to its
nature the spread of the gangrene is seldom arrested by the natural
protective processes, and it usually continues until the condition
proves fatal from the absorption of toxins into the circulation.

The _clinical features_ vary in the different varieties of moist
gangrene, but the local results of bacterial action and the
constitutional disturbance associated with toxin absorption are present
in all; the prognosis therefore is grave in the extreme.

From what has been said, it will be gathered that in dry gangrene there
is no urgent call for operation to save the patient's life, the primary
indication being to prevent the access of bacteria to the dead part, and
especially to the surface exposed at the line of demarcation. In moist
gangrene, on the contrary, organisms having already obtained a footing,
immediate removal of the dead and dying tissues, as a rule, offers the
only hope of saving life.

VARIETIES OF GANGRENE

#Varieties of Gangrene essentially due to Interference with the
Circulation#

While the varieties of gangrene included in this group depend primarily
on interference with the circulation, it is to be borne in mind that the
clinical course of the affection may be profoundly influenced by
superadded infection with micro-organisms. Although the bacteria do not
play the most important part in producing tissue necrosis, their
subsequent introduction is an accident of such importance that it may
change the whole aspect of affairs and convert a dry form of gangrene
into one of the moist type. Moreover, the low state of vitality of the
tissues, and the extreme difficulty of securing and maintaining asepsis,
make it a sequel of great frequency.

#Senile Gangrene.#--Senile gangrene is the commonest example of local
death produced by a _gradual_ diminution in the quantity of blood
passing through the parts, as a result of arterio-sclerosis or other
chronic disease of the arteries leading to diminution of their calibre.
It is the most characteristic example of the dry type of gangrene. As
the term indicates, it occurs in old persons, but the patient's age is
to be reckoned by the condition of his arteries rather than by the
number of his years. Thus the vessels of a comparatively young man who
has suffered from syphilis and been addicted to alcohol are more liable
to atheromatous degeneration leading to this form of gangrene than are
those of a much older man who has lived a regular and abstemious life.
This form of gangrene is much more common in men than in women. While it
usually attacks only one foot, it is not uncommon for the other foot to
be affected after an interval, and in some cases it is bilateral from
the outset. It must clearly be understood that any form of gangrene may
occur in old persons, the term senile being here restricted to that
variety which results from arterio-sclerosis.

[Illustration: FIG. 20.--Senile Gangrene of the Foot, showing line of
demarcation.]

_Clinical Features._--The commonest seat of the disease is in the toes,
especially the great toe, whence it spreads up the foot to the heel, or
even to the leg (Fig. 20). There is often a history of some slight
injury preceding its onset. The vitality of the tissues is so low that
the balance between life and death may be turned by the most trivial
injury, such as a cut while paring a toe-nail or a corn, a blister
caused by an ill-fitting shoe or the contact of a hot-bottle. In some
cases the actual gangrene is determined by thrombosis of the popliteal
or tibial arteries, which are already narrowed by obliterating
endarteritis.

It is common to find that the patient has been troubled for a long time
before the onset of definite signs of gangrene, with cold feet, with
tingling and loss of feeling, or a peculiar sensation as if walking on
cotton wool.

The first evidence of the death of the part varies in different cases.
Sometimes a dark-blue spot appears on the medial side of the great toe
and gradually increases in size; or a blister containing blood-stained
fluid may form. Streaks or patches of dark-blue mottling appear higher
up on the foot or leg. In other cases a small sore surrounded by a
congested areola forms in relation to the nail and refuses to heal. Such
sores on the toes of old persons are always to be looked upon with
suspicion and treated with the greatest care; and the urine should be
examined for sugar. There is often severe, deep-seated pain of a
neuralgic character, with cramps in the limb, and these may persist long
after a line of demarcation has formed. The dying part loses sensibility
to touch and becomes cold and shrivelled.

All the physical appearances and clinical symptoms associated with dry
gangrene supervene, and the dead portion is delimited by a line of
demarcation. If this forms slowly and irregularly it indicates a very
unsatisfactory condition of the circulation; while, if it forms quickly
and decidedly, the presumption is that the circulation in the parts
above is fairly good. The separation of the dead part is always attended
with the risk of infection taking place, and should this occur, the
temperature rises and other evidences of toxaemia appear.

_Prophylaxis._--The toes and feet of old people, the condition of whose
circulation predisposes them to gangrene, should be protected from
slight injuries such as may be received while paring nails, cutting
corns, or wearing ill-fitting boots. The patient should also be warned
of the risk of exposure to cold, the use of hot-bottles, and of placing
the feet near a fire. Attempts have been made to improve the peripheral
circulation by establishing an anastomosis between the main artery of a
limb and its companion vein, so that arterial blood may reach the
peripheral capillaries--reversal of the circulation--but the clinical
results have proved disappointing. (See _Op. Surg._, p. 29.)

_Treatment._--When there is evidence that gangrene has occurred, the
first indication is to prevent infection by purifying the part, and
after careful drying to wrap it in a thick layer of absorbent and
antiseptic wool, retained in place by a loosely applied bandage. A
slight degree of elevation of the limb is an advantage, but it must not
be sufficient to diminish the amount of blood entering the part.
Hot-bottles are to be used with the utmost caution. As absolute dryness
is essential, ointments or other greasy dressings are to be avoided, as
they tend to prevent evaporation from the skin. Opium should be given
freely to alleviate pain. Stimulation is to be avoided, and the patient
should be carefully dieted.

When the gangrene is limited to the toes in old and feeble patients,
some surgeons advocate the expectant method of treatment, waiting for a
line of demarcation to form and allowing the dead part to be separated.
This takes place so slowly, however, that it necessitates the patient
being laid up for many weeks, or even months; and we agree with the
majority in advising early amputation.

In this connection it is worthy of note that there are certain points at
which gangrene naturally tends to become arrested--namely, at the highly
vascular areas in the neighbourhood of joints. Thus gangrene of the
great toe often stops when it reaches the metatarso-phalangeal joint; or
if it trespasses this limit it may be arrested either at the
tarso-metatarsal or at the ankle joint. If these be passed, it usually
spreads up the leg to just below the knee before signs of arrestment
appear. Further, it is seen from pathological specimens that the spread
is greater on the dorsal than on the plantar aspect, and that the death
of skin and subcutaneous tissues extends higher than that of bone and
muscle.

These facts furnish us with indications as to the seat and method of
amputation. Experience has proved that in senile gangrene of the lower
extremity the most reliable and satisfactory results are obtained by
amputating in the region of the knee, care being taken to perform the
operation so as to leave the prepatellar anastomosis intact by retaining
the patella in the anterior flap. The most satisfactory operation in
these cases is Gritti's supra-condylar amputation. Haemorrhage is easily
controlled by digital pressure, and the use of a tourniquet should be
dispensed with, as the constriction of the limb is liable to interfere
with the vitality of the flaps.

When the tibial vessels can be felt pulsating at the ankle it may be
justifiable, if the patient urgently desires it, to amputate lower than
the knee; but there is considerable risk of gangrene recurring in the
stump and necessitating a second operation.

That amputation for senile gangrene performed between the ankle and the
knee seldom succeeds, is explained by the fact that the vascular
obstruction is usually in the upper part of the posterior tibial artery,
and the operation is therefore performed through tissues with an
inadequate blood supply. It is not uncommon, indeed, on amputating above
the knee, to find even the popliteal artery plugged by a clot. This
should be removed at the amputation by squeezing the vessel from above
downward by a "milking" movement, or by "catheterising the artery" with
the aid of a cannula with a terminal aperture.

It is to be borne in mind that the object of amputation in these cases
is merely to remove the gangrenous part, and so relieve the patient of
the discomfort and the risks from infection which its presence involves.
While it is true that in many of these patients the operation is borne
remarkably well, it must be borne in mind that those who suffer from
senile gangrene are of necessity bad lives, and a guarded opinion should
be expressed as to the prospects of survival. The possibility of the
disease developing in the other limb has already been referred to.

[Illustration: FIG. 21.--Embolic Gangrene of Hand and Arm.]

#Embolic Gangrene# (Fig. 21).--This is the most typical form of gangrene
resulting from the _sudden_ occlusion of the main artery of a part,
whether by the impaction of an embolus or the formation of a thrombus in
its lumen, when the collateral circulation is not sufficiently free to
maintain the vitality of the tissues.

There is sudden pain at the site of impaction of the embolus, and the
pulses beyond are lost. The limb becomes cold, numb, insensitive, and
powerless. It is often pale at first--hence the term "white gangrene"
sometimes applicable to the early appearances, which closely resemble
those presented by the limb of a corpse.

If the part is aseptic it shrivels, and presents the ordinary features
of dry gangrene. It is liable, however, especially in the lower
extremity and when the veins also are obstructed, to become infected and
to assume the characters of the moist type.

The extent of the gangrene depends upon the site of impaction of the
embolus, thus if the _abdominal aorta_ becomes suddenly occluded by an
embolus at its bifurcation, the obstruction of the iliacs and femorals
induces symmetrical gangrene of both extremities as high as the inguinal
ligaments. When gangrene follows occlusion of the _external iliac_ or of
the _femoral artery_ above the origin of its deep branch, the death of
the limb extends as high as the middle or upper third of the thigh. When
the _femoral_ below the origin of its deep branch or the _popliteal
artery_ is obstructed, the veins remaining pervious, the anastomosis
through the profunda is sufficient to maintain the vascular supply, and
gangrene does not necessarily follow. The rupture of a popliteal
aneurysm, however, by compressing the vein and the articular branches,
usually determines gangrene. When an embolus becomes impacted at the
_bifurcation of the popliteal_, if gangrene ensues it usually spreads
well up the leg.

When the _axillary artery_ is the seat of embolic impaction, and
gangrene ensues, the process usually reaches the middle of the upper
arm. Gangrene following the blocking of the _brachial_ at its
bifurcation usually extends as far as the junction of the lower and
middle thirds of the forearm.

Gangrene due to thrombosis or embolism is sometimes met with in patients
recovering from typhus, typhoid, or other fevers, such as that
associated with child-bed. It occurs in peripheral parts, such as the
toes, fingers, nose, or ears.

_Treatment._--The general treatment of embolic gangrene is the same as
that for the senile form. Success has followed opening the artery and
removing the embolus. The artery is exposed at the seat of impaction
and, having been clamped above and below, a longitudinal opening is made
and the clot carefully extracted with the aid of forceps; it is
sometimes unexpectedly long (one recorded from the femoral artery
measured nearly 34 inches); the wound in the artery is then sewn up with
fine silk soaked in paraffin. When amputation is indicated, it must be
performed sufficiently high to ensure a free vascular supply to the
flaps.

#Gangrene following Ligation of Arteries.#--After the ligation of an
artery in its continuity--for example, in the treatment of aneurysm--the
limb may for some days remain in a condition verging on gangrene, the
distal parts being cold, devoid of sensation, and powerless. As the
collateral circulation is established, the vitality of the tissues is
gradually restored and these symptoms pass off. In some cases,
however,--and especially in the lower extremity--gangrene ensues and
presents the same characters as those resulting from embolism. It tends
to be of the dry type. The occlusion of the vein as well as the artery
is not found to increase the risk of gangrene.

#Gangrene from Mechanical Constriction of the Vessels of the part.#--The
application of a bandage or plaster-of-Paris case too tightly, or of a
tourniquet for too long a time, has been known to lead to death of the
part beyond; but such cases are rare, as are also those due to the
pressure of a fractured bone or of a tumour on a large artery or vein.
When gangrene occurs from such causes, it tends to be of the moist type.

Much commoner is it to meet with localised areas of necrosis due to the
excessive _pressure of splints_ over bony prominences, such as the
lateral malleolus, the medial condyle of the humerus, or femur, or over
the dorsum of the foot. This is especially liable to occur when the
nutrition of the skin is depressed by any interference with its
nerve-supply, such as follows injuries to the spine or peripheral
nerves, disease of the brain, or acute anterior poliomyelitis. When the
splint is removed the skin pressed upon is found to be of a pale yellow
or grey colour, and is surrounded by a ring of hyperaemia. If protected
from infection, the clinical course is that of dry gangrene.

Bed-sores, which are closely allied to pressure sores, will be described
at the end of this chapter.

When a localised portion of tissue, for example, a piece of skin, is so
severely _crushed_ or _bruised_ that its blood vessels are occluded and
its structure destroyed, it dies, and, if not infected with bacteria,
dries up, and the shrivelled brown skin is slowly separated by the
growth of granulation tissue beneath and around it.

Fingers, toes, or even considerable portions of limbs may in the same
way be suddenly destroyed by severe trauma, and undergo mummification.
If organisms gain access, typical moist gangrene may ensue, or changes
similar to those of ordinary post-mortem decomposition may take place.

_Treatment._--The first indication is to exclude bacteria by purifying
the damaged part and its surroundings, and applying dry, non-irritating
dressings.

When these measures are successful, dry gangrene ensues. The raw surface
left after the separation of the dead skin may be allowed to heal by
granulation, or may be covered by skin-grafts. In the case of a finger
or a limb it is not necessary to wait until spontaneous separation takes
place, as this is often a slow process. When a well-marked line of
demarcation has formed, amputation may be performed just sufficiently
far above it to enable suitable flaps to be made.

The end of a stump, after spontaneous separation of the gangrenous
portion, requires to be trimmed, sufficient bone being removed to permit
of the soft parts coming together.