Management
of missile Injuries
Missile
wounds of soft tissue
Management of the soft tissue wound is a formal procedure consisting of
clearly defined stages. This is the part of early management most frequently
neglected by surgeons with limited or no experience of war surgery. The entrance
and exit wounds do not indicate the considerable damage that may have occurred
to deeper structures (Fig. 19.4).
This
can only be detected by full exploration. In limb wounds, exploration is
followed by thorough wound excision, after which, with very few exceptions,
the wound should be left open. Delayed primary closure should follow within
4—7 days after injury. Having followed the Advanced Trauma Life Support (ATLS®)
guidelines, the patient will have been completely undressed prior to surgery,
but it is wise to retain any pressure dressings over a wound until the operation
is due to begin. The operation should consist of the following stages.
1.
After photographing the wound and cleaning it with au antiseptic,
generous longitudinal incisions are made through the skin to allow visualisation
and access to the deeper structures and to facilitate subsequent extension of
the exposure, should this be required. A minimal amount of skin edge (i.e. only
that which has been contaminated)
2. The deep fascia is exposed over the length of the skin incisions, and
must be incised in a longitudinal direction to allow full inspection of the area
damaged by the wounding missile and to decompress the underlying muscle which
will swell subsequently. This is the true meaning of the much misused term débridement
(Fig. 19.5).
3. Neurovascular bundles in the wound track must
be identified and examined, but nerves should not be dissected out at the
initial exploration. Nerves considered to be injured and warranting later
exploration may have their position marked with a nonabsorbable suture marker to
ease subsequent identification. It is important to examine the patient for nerve
injury before the operation if this is possible and to record in the operation
notes the nature of the nerve injury. The majority of nerve injuries is
neuropraxias which do recover.
‘Débridement
(unbridling or unleashing). The term was introduced by Baron Dominique Jean
Larrey, 1766—1842, Surgeon to Napoleon’s Imperial Guard. He used it to
describe the process of laying a wound open to facilitate removal of bullets,
bits of loose cloth, detached pieces of bone and soft tissue. He and his
contemporaries did not excise tissue in the modern sense and his procedure was
much less extensive than the formal wound excision practised today.
4. Foreign matter should be removed from the wound. Pieces of clothing
are especially sought, both in the missile track and in the tissue planes on
either side. It is not necessary to remove every piece of metal seen on a
radiograph. Multiple, very small metal fragments from modern munitions may, in
any case, be very difficult to locate and remove.
5.
Dead muscle that does not bleed
or contract, is mushy in consistency or has an unhealthy colour must be excised.
These criteria comprise is the ‘4 Cs’ for muscle excision
The 4 Cs’
• Colour
• Contractility
• Consistency
• Capillary bleeding
6. Tendon repair should not be performed at this initial procedure.
Tattered ends should be trimmed.
7. Major artery and vein damage must be noted. Where possible, the ends
should be trimmed and sutured. If any tension is likely to develop, a reversed
vein graft may be inserted to bridge the gap and the repair covered by healthy
muscle. The rest of the wound should be left open for delayed primary closure.
Synthetic grafts must not be used. A plastic shunt inserted into an injured
artery can be used to revitalise tissue distal to the site of injury prior to
definitive repair. In combined arterial and venous injury, concomitant shunting
of both vessels may be undertaken. Temporary shunting has a vital role where
major vascular damage is associated with fractures of long bones. In this
instance, blood flow is established via the shunt(s), and the fracture is
reduced and immobilised using an external fixator, after which definitive
vascular repair is undertaken.
8. Bone shattered by high-energy transfer will in many instances still
have attachment to periosteum or muscle. Such fragments must not be discarded.
Loss of bone may result in malunion (e.g. shortening) or nonunion. Contaminated
bone may be cleaned by using that useful instrument of military surgery, the
Volkmann’s spoon or curette.
9. Injured joints need thorough inspection and cleaning by copious
irrigation with saline to remove organic matter. Any exposed articular cartilage
should be covered by at least one layer of healthy tissue, preferably synovium,
otherwise muscle or skin should be used.
10. At the end of the operation the wound should
be irrigated thoroughly with saline to remove any remaining debris.
Haemostasis should be secured with the aid of hot packs and the wound left open
without closure of either fascial layer or skin, even in the presence of exposed
bone. A lightly fluffed gauze dressing should be placed over the wound to allow
free drainage. Packing must be avoided.
11. Immobilisation in a well-padded splint allows
the soft tissues to recover, a principle expounded by Hugh Owen Thomas at the
turn of the century. Split plaster of Paris splints are ideal even in the
absence of a fracture. Femoral shaft fractures should be immobilised in a
traction splint.
12. Antibiotic cover is advised for all wounds;
third-generation cephalosporins or agents with an equivalent spectrum being
ideal. In all abdominal, pelvic and perineal wounds, metranidazole is given in
addition (see Chapter 7).
Traumatic
amputations
Traumatic amputations should be surgically tidied, completed at the
lowest level possible and the skin left open for delayed primary closure. If
there is much skin loss or if a limb is very swollen, split skin grafting may be
used to effect wound closure in order to avoid skin tension. If, at the time of
delayed primary closure, dead muscle is found, which is not uncommon in
traumatic amputation due to antipersonnel mines, the muscle is excised and the
wound left open for a further period before closure.
Missile
wounds of the abdomen
Every penetrating and perforating missile wound of the abdomen should be
explored by laparotomy. Before surgery, a nasogastric tube should be passed into
the stomach and a urinary catheter into the bladder. Bladder catheterisation
must be preceded by a digital rectal examination. Timing of exploration will
vary. In some cases, operation will be undertaken as part of resuscitation
leaving little or no time for planning (see the section on ‘Damage control’
in Chapter 18). In others, preoperative stabilisation is possible and time is
available for investigation, including haematology, biochemistry and
radiology. In all cases blood in realistic quantities must be available.
A
full midline incision from xiphisternum to pubis is recommended. It has the
advantage of facilitating rapid access and extension laterally or into the chest
where required. The commonest source of bleeding in survivors is from the small
bowel mesentery, but major haemorrhage may come from the solid organs, such as
liver or spleen, or from the major vessels. Haemorrhage must be controlled and
careful examination is then made of all the abdominal contents.
In
all wounds of the stomach, the lesser sac must be opened to inspect the
posterior gastric wall. Retroperitoneal haematoma in the region of the duodenum
requires inspection of its posterior wall by Kocher’s method (Chapter 51). Haematoma
surrounding the retroperitoneal parts of the ascending and descending colon may
also necessitate exploration, but nonexpanding retroperitoneal haematomas over
the kidneys are best left undisturbed.
Small
intestinal perforations are either
excised and closed transversely, or the damaged section is resected if there are
multiple holes in a short length (Fig. 19.6) Mesenteric tears may also require
bowel resection (see Chapter 56).
Colon
and rectal wounds (see also Chapter 57)
For most injuries of the right side of the colon, primary repair
or primary resection is satisfactory. Occasionally, where severe wounding with
extensive contamination has occurred, a vented ileotransverse anastomosts is
warranted. Rarely, the two ends are brought to the surface as proximal ileostomy
and distal mucous fistula, respectively.
On
the left side a one-stage procedure may be undertaken if favourable
circumstances pertain, i.e. minimal peritoneal contamination, limited blood
loss, and a time interval between injury and operation of less than 8 hours.
However, if injury is associated with high-risk factors, the injured colon is
resected and the proximal end brought out as a colostomy and the distal end as a
mucous fistula. If the distal end cannot be brought to the surface, as in low
sigmoid or rectal injuries, it may be closed off as in a Hartmann procedure
(Chapter 60). Subsequent restoration of bowel continuity will be required.
Extraperitoneal
rectal injuries are repaired if
feasible and defunctioned by establishing a sigmoid end colostomy.Good
Rectal
in jury
Renal injury is best treated conservatively if this is possible.
Fortunately, immediate nephrectomy is rarely indicated. A divided ureter may be
brought to the surface or may be repaired over a ‘pigtail’ stent.
Bladder
and urethral injuries
Bladder and urethral injuries are treated by suprapubic cystostomy with
placement of a suprapubic drain after wound excision.
Liver
injuries
In 50 per cent of cases of hepatic injury surviving to reach a surgical
centre, bleeding has stopped and is not a problem at laparotomy, a reassuring
statistic for the youthful surgeons usually faced with such cases. Where
bleeding is still occurring, damage control techniques are particularly
appropriate in a warfare setting (see section on ‘Damage control’ in Chapter
18). Manual compression and perihepatic packing are recommended, and may allow a
patient to survive to reach a more sophisticated surgical facility in the rear
of the fighting area, If these simple measures do not work, and provided that
the operator is experienced, finger fracture with exposure of bleeding points
followed by individual ligation, or more formal resection procedures, will be
needed (see also Chapter 52). These are rare eventualities. In all cases, generous
drainage of the spaces surrounding the liver is important.
Damage
to the spleen and pancreas
Damage to the spleen and tail of pancreas may require resection,
although in some cases splenorrhaphy may be feasible. Missile injury of the head
of the pancreas is seldom seen in the operating room because injury to it and
surrounding structures is usually fatal. In a very few cases it may be possible
to apply a Roux loop of jejenum to create an internal fistula.
Peritoneal
toilet
Using warm saline, it is important to assist the removal of all spilled
bowel contents and blood clot.
Closure
The laparotomy wound is closed using the mass closure technique. The
missile entrance and exit wounds should be excised as described earlier and left
open initially with a view to delayed primary closure at 4—6 days.
Missile
wounds of the chest
(See also Chapter 47.) Penetrating missile wounds of the chest are
common in war and are associated with a high mortality if simple life-saving
measures are neglected. Iris important to secure an airtight seal of open
wounds of the chest to prevent a potentially fatal open pneumothorax. This is
immediately followed by tube thoracostomy. This should been done during the
primary survey. Failure to do so will result in collapse of the lung on the
affected side with alteration of the ventilation/perfusion ratio and, in
addition, will progressively decrease the quantity and quality of air entering
the affected lung. As dyspnoea increases due to anoxia, the mediastinum shifts
on respiration and decreases venous return to the heart — the clinical picture
in the later stages is identical to a tension pneumothorax.
All
penetrating wounds of the chest require adequate venting of the pleura by
formal tube thoracostomy. This simple procedure will prevent the accumulation of
blood or air under tension. The position of the tube should be confirmed by
chest radiography. Once pulmonary function has been stabilised, missile entry
and exit wounds are excised. During the excision of a large chest wall wound,
the pleural cavity is often entered; this need not cause concern. The
opportunity should be taken to remove any retained foreign material, arrest
haemorrhage (usually from an intercostal or internal mammary vessel) and to
oversew or staple holes in the adjacent lung. On completion the pleural
opening must be sealed either by direct pleural closure (often difficult) or by
utilising overlying healthy soft tissue, and the wound(s) left open for
subsequent delayed primary closure.
These
simple measures will suffice for more than 80 per cent of chest wounds. The
remainder will require formal thoracotomy, often urgently. The usual indications
are listed below.
Indications for formal thoracotomy
• More than 1.5 litres initial blood loss
• Continuing loss of > 200 mI/hour
• Cardiac tamponade
• Other mediastinal injuries
• Persistent air leak
• Retained foreign bodies > 1.5 cm in diameter
Even
in cases where thoracotomy is indicated, considerable delay can often be
tolerated provided adequate resuscitation is initiated quickly. Thoracotomy for
retained foreign bodies is often a late and planned procedure.
In
thoracoabdominal injuries, the thoracic component is treated by tube
thoracostomy and the abdominal component by laparotomy through a midline
incision. Formal thoracoabdominal incisions risk contamination of the chest
cavity by faeces and should be avoided.
Missile
wounds of the head
The penetrating high-energy transfer missile wound of the head is
usually lethal. The management of penetrating low-
energy transfer and tangential wounds depends initially on measures
described in the primary survey and resuscitation phases (see Chapter 18). These
will ensure a protected airway, adequate ventilation, and maintenance of blood
pressure and perfusion pressure to permit oxygenation of the brain. Good
radiographs are mandatory to localise foreign bodies and bone fragments.
Computerised tomography (CT) images are invaluable in planning surgical
exploration. Wound excision should be carried out using gentle irrigation and
suction to remove devitalised brain and bony fragments. Every effort, including
the use of temporalis fascia or fascia lata, should be made to close overlying
dura. The skin overlying the head and face is an exception to the delayed
primary closure rule. Blood supply is excellent, allowing primary closure which
also serves to control blood loss from the scalp.
Intermittent
positive pressure ventilation (IPPV) assists in the reduction of intracranial
pressure by reducing brain swelling. Intracranial pressure transducers inserted
through burr holes may be employed to monitor intracranial pressure in the
postoperative phase.
Shotgun
injuries
Accidents from large-bore shotguns are common and often lethal when
injury is sustained at close range. It is never possible to retrieve all the
shot and, indeed, to do so would result in unacceptable damage to uninjured soft
tissues. Wound excision should be carried out on the major wound, particularly
looking for indniven wadding and plugs of clothing. Laparotomy is essential if
it is thought that any of the shot has traversed an abdominal viscus. The
retention of lead shot in the body can result in a dangerously high lead
oncentration, which should be monitored. After a time, this 2oncentration will
fall as a result of encapsulation of the lead pellets by fibrous tissue.
Summary:
dos and don’ts of missile injuries
Do:
•incise skin generously;
•incise
fascia widely;
• identify neurovascular bundles; excise all devitalised tissue;
•remove all indriven
clothing;
• leave wound open at end of surgery;
•dress wounds with fluffed
gauze;
•record all injuries in
the notes.
Don’t:
•excise
too much skin;
•practise
keyhole surgery; repair tendons or nerves;
•remove
attached pieces of bone; close the deep fascia;
•insert
synthetic prostheses;
•pack
the wound;
•close
the skin.