What is Gangrene
Gangrene is defined as a localized death and decomposition of body tissue, resulting
from obstructed circulation or bacterial infection. Foot gangrene, as a part of
diabetes or atherosclerosis, has become a major medical problem. When gangrene sets
in, an amputation needs to be performed.
An amputation, one of the oldest surgical procedures, usually refers to the surgical
removal of the whole or part of a lower or upper extremity - a foot/leg or a hand/arm.
Amputation, however, should be attempted only after all forms of treatment have
been exhausted.
The vast majority of amputations are performed due to vascular disease. Blockages
in the arteries result in insufficient blood supply to the limb.
When narrowing or hardening of the arteries becomes severe, gangrene develops and
amputation may be the only option Because diabetes can cause vascular blockages,
about 30 - 40 percent of amputations are performed in diabetics. The estimated risk
for major amputation in diabetics is 15 to 40 times higher than the general population.
In fact, amputations are an extremely feared complication of diabetes as diabetics
also often loose their protective sensation and may form ulcerative complications,
such as osteomyelitis - an acute or chronic inflammatory process of the bone and
its structures.
If Gangrene is left untreated - depending on the severity of someone's condition
- infection can develop and threaten the life of the patient. If amputation is not
performed, in these circumstances gangrene can be fatal.
How do you prevent gangrene from occurring?
One of the earliest signs of decreased blood supply to the legs is pain or discomfort
in the legs on walking. This pain decreases as soon as the person stops exercise.
This is called intermittent claudication, and is due to an imbalance between the
blood supply to the legs and the demand of the muscles during exercise. As the severity
of the blockages increases, the distance that the person can walk decreases. With
severe degree of narrowing of the blood vessels, the person can develop pain in
the legs even during rest. If the blood vessel closes completely, and there is inadequate
flow via small bypass (collateral) arteries, then the tissue of the legs will die,
resulting in Gangrene.
If diagnosed in the early stages, certain medications such as Pentoxyphylline and
Cilostazol are used, which help to deliver more blood supply to the tissues. In
later stages, with advanced blockages, either Interventional technique such as Balloon
Angioplasty and/or Stent Placement may be used to open up the narrowed and blocked
arteries, and to restore blood supply to the legs. With advances in technology and
newer equipment, even advanced degree of blockages can be opened up by these non
surgical techniques in many instances.
Sometimes, when Interventional techniques are not feasible, then open Vascular Surgery
may be performed using a bypass channel. It is important to note that once gangrene
has developed, then the dead tissue has to be removed surgically. In such cases,
the role of Interventional techniques is to restore the blood supply as far as possible,
and prevent the gangrene from spreading, leading to amputation of a major part of
the limb. For example if the gangrene has already affected the Great toe of the
foot, then the great toe will need to be removed surgically. However, opening up
of the blocked artery below the knee will help to prevent spread of Gangrene further
into the foot; if this occurs, the patient may need either above knee or below knee
amputation. The purpose of treatment is to save as much of the limb as possible.
Blockages of the arteries of the lower limbs, may start right from the Abdominal
aorta to the vessels of the foot.
The cases outlined below will illustrate the type of blockages which can be treated
by Interventional techniques. This treatment is performed in a special laboratory,
called the Digital Subtraction Angiography Suite. Most procedures are conducted
using local anesthetic, although in some cases sedation may be used. In the vast
majority of cases the patient may need hospitalization only for a couple of days,
for opening up of the arteries. However, if the patient has already developed Gangrene,
then treatment of the gangrenous tissue ( if necessary amputation of the affected
part) may take a few days more.
Along with Interventional techniques, Hyperbaric Oxygen treatment is also used to
increase the blood supply to the affected tissues. In this technique, the patient
is placed in a special Hyperbaric Oxygen chamber, and he breathes pure 100% oxygen
under pressure for one hour every day. This increases the oxygen content of the
blood and delivers increased oxygen to the tissues which are supplied by narrowed
or blocked arteries.