The
chest wall
Tumours
of the chest wall
These can be tumours of any component of the chest wall, i.e. bone,
cartilage and soft tissue. They are treated similarly to those that occur in
other sites and only require specialist input if major resection and chest
wall’ reconstruction are contemplated.
Most
lesions may be seen on a chest radiograph but occasionally CT or isotope bone
scanning is required. Excision biopsy is often the best way to deal with a rib
neoplasm because the differentiation between benign and malignant growths may be
difficult. This avoids the risk of ‘spillage’ and tumour seeding in the
wound of an incision biopsy. If a major resection is to be planned, it may be
preferable to know the nature of the lesion before surgery. The principle of
surgery .s to remove the rib along with the rib immediately above and below, and
a length well past the margins of the tumour. Reconstruction is possible using a
prosthetic material Marlex or acrylic plates) to provide some stability to the
:hest wall. Myocutaneous flaps are occasionally employed to over extensive
tissue defects and therefore prior discussion with a plastic and reconstructive
surgeon may be useful.
For
lesions that are not amenable to resection, chemotherapy or radiotherapy,
although unlikely to be curative, may provide symptomatic relief.
Other
diseases of the chest wall
Congenital abnormalities are often incidental findings on chest
radiography (bifid rib) but there are some important exceptions.
Cervical
rib
This rib is usually represented by a fibrous band originating from the
seventh cervical vertebra and inserting on to the first thoracic rib. It may be
asymptomatic but because the axillary artery and brachial plexus course over it
a variety of symptoms may occur. The lower trunk of the plexus (mainly T1)
is compressed, leading to wasting of the interossei and altered sensation in the
T1 distribution. Compression of the axillary artery may result in a
post stenotic dilatation with thrombus and embolus formation. Treatment is by
division or removal of the rib by a supraclavicular or an axillary approach.
Pectus
excavatum
The sternum is depressed, with a dish-shaped deformity of the anterior
portions of the ribs on one or both sides. It is probably never a cause of
respiratory problems but may coexist with asthma, which is a common condition of
children and young people. It may come to light during the growth spurt at
adolescence when, of course, the teenager is particularly sensitive about
appearance. Most patients are asymptomatic and the only justification for
treatment is on cosmetic grounds. Some surgeons, and their referring doctors,
make a very good case for this but the risk of morbidity and of a less than
perfect result must be clearly spelt out to the patients and their parents.
The
operation involves mobilising the sternum with the costal cartilages and holding
this central panel anteriorly with a steel bar. Surgery is best left until the
late ‘teens when further growth of the chest wall is unlikely. It is worth
recommending some body-building exercises because muscle development not only
masks the skeletal deformity but boosts confidence.
Pectus
carinatum (pigeon chest)
In this condition the sternum is elevated above the level of the ribs
and treatment is offered for cosmetic reasons. The sternum is mobilised and
allowed to fall back into place.
Pulmonary
sepsis
Infections
of the chest wall
These are unusual but may occur following osteomyelitis of the
underlying rib. An empyema of the underlying thoracic cavity may discharge
through the chest wall (empyema necessitans) leaving a chronic sinus. Sterile
pus should alert
Empyema
This is the end point of a number of conditions that result in the
presence of pus in the pleural space, pleural thickening surrounding the
walled-off infection and finally restricted lung movement on the affected side
as a result of fibrosis. The presence of white cells and organisms is not
sufficient to make the diagnosis of empyema.
The
classic aetiology and still probably the most common is postpneumonic. A
‘syn-pneumonic effusion’ becomes colonised by bacteria and, at this stage,
there is turbid but thin fluid, minimal pleural thickening and a mobile
underlying lung. This is nor properly called an empyema, an important point
because the old-fashioned methods of rib resection would be fatal if applied to
this condition and simpler treatments are effective. Untreated, this infected
effusion develops into an empyema with thick pus in the pleural space surrounded
by inflamed pleura thickened by deposition of fibrin. Finally, the cortex
organises to form dense scar tissue or a ‘fibrothorax’. Any cause of fluid
collection, once contaminated, can evolve to reach this same end point (Table
47.6). Once established, any contaminated collection in the chest can result in
empyema.
Symptoms.
There are symptoms of pus at any site, namely swinging pyrexia with general
malaise. Finger clubbing and weight loss are signs of chronicity. Progressive
dyspnoea occurs as the hemithorax becomes more rigid. There may also be signs
and symptoms of various predisposing conditions (see above). Pus may discharge
into the overlying skin (empyema necessitans). Since the introduction of
antibiotics, chronic empyema is not often seen but it is still a serious problem
when it occurs.
Treatment.
The management depends on the stage of the empyema.
Early
empyema (thin pus, mobile lung and
thin pleura). At this stage a brief period of pleural drainage, with underwater
seal and adequate dosage of appropriate antibiotics, should result in resolution
but inadequate treatment or no treatment will lead to a chronic empyema — a
much more serious problem. Complete drainage and re-expansion of the lung should
be achieved before the drains are removed. This need not take more than 2—3
days. Pus should be sent for microscopy and culture before antibiotic therapy.
Established
empyema (adherent lung caused by inflamed and thickened pleura with thick pus in
the empyema space). At this stage the old treatment of rib resection with open
drainage is safe in that the lung is tethered. However, it is inelegant,
protracted and incomplete in its results. It is better to insert drains, through
a small thoracotomy (with resection of rib) if practical. This is best done
under a general anaesthetic, except in desperate circumstances, and all the
loculi are broken down, ensuring free drainage and the siring of one or two
carefully situated tubes. The drains should span the cavity, have the last side
hole just within the ribs, and be tracked to lie anterior to the midaxillary
line so that they are comfortable and do not kink as the patient lies back.
Video-assisted
thoracoscopic placement of drains is an increasingly appropriate alternative
approach. Suction drainage is employed on chest closure and this is continued
until the patient is ready for mobilisation. Provided there is no air leak (and
there is usually none) portable vacuum drains, which the patient is able to
manage at home, are inserted. Appropriate antibiotics are also given. A daily
record of the amount drained is kept by the patient and, once the drainage is
less than 25—5 0 ml/24 hours of serous fluid (it never becomes zero),
the drain is removed.
Chronic
empyema. If progression to a chronic fibrothorax has occurred, aspiration or
drainage of pus will not lead to expansion of the lung because there is
considerable fibrosis constricting the lung parenchyma.
Thoracotomy
and decortication. A formal
thoracotomy is performed and the thickened parietal pleura and the fibrin peel
overlying the lung are painstakingly removed, piecemeal if necessary. This
allows the lung to expand but theme is often considerable blood loss from the
raw surfaces. Wide bore drains are inserted and connected to an underwater
drainage system. Protracted air leak is common. When the leak has stopped (often
up to 10 days later), the drains are removed. Antibiotics are given to cover
organisms grown from the pus.
Postpneumonectomy
empyema
This is discussed in the section concerning lung resections.
Lung
abscess
Abscesses in the lung do not occur unless the underlying infection has
caused thrombosis of the segmental artery and vein leading to infection with
tissue necrosis. The most common causes are secondary to a chronic upper
respiratory
Diagnosis
and treatment. The chest radiograph usually demonstrates a cavitating shadow
which is similar in appearance to a necrotic bronchial carcinoma or less
commonly a fungal infection. The diagnosis is confirmed with a combination of
sputum culture, bronchoscopy and radiography. Most acute abscesses resolve with
appropriate antibiotic therapy and postural drainage. The course of antibiotics
is usually the highest permitted dose for a prolonged period. The virulent
organism may change with such a prolonged antibiotic assault and the sputum must
therefore be regularly monitored. Surgery is not usually part of the treatment.
It is better for a lung abscess to drain via the bronchus and the contents are
coughed up. Inserting a percutaneous drain creates a particularly difficult form
of bronchopleural fistula.