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334 Chest Wall Deformities

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as help to evaluate the thoracic spine (Figures 53.5 and 53.6). A com-
puted tomography (CT) scan of the chest has been considered the gold
standard investigation in PE (Figure 53.7). It allows the calculation of
the Haller index, the ratio of the transverse to the AP diameter at the
lowest point of the depression. Other information obtained includes the
length of the depression, degree of sternal torsion, and presence of chest
5
wall asymmetry. Although recommended by some, we do not routinely
carry out a CT scan of the chest or calculate the Haller index, as they do
not influence the operative technique or outcome.
Indications for Surgery
Surgery for PE is carried out mainly to improve the appearance of the
deformity. However, in some severe cases, two or more of the following
are considered an indication for surgery: 7
Figure 53.7: CT scan showing sternal torsion, asymmetrical chest, and a
• a Haller index of greater than 3.25 plus the presence of cardiac or measure for the Haller index by calculating AB/CD.
pulmonary compression.
• Demonstrable cardiac abnormalities.
• Decreased pulmonary function; and
• Previous failed repair by Ravitch or Nuss procedures.
The Nuss procedure is ideally performed between 10 and 12 years
of age, taking advantage of the pliability of the chest wall. The child
in this age group, however, is often immature and unable to make
an educated decision on whether to undergo such a major procedure
mainly for cosmetic reasons. The patient should be Gillick competent
to give informed consent. A single bar achieves good correction at this
age. Two bars are recommended for the postpubertal patient, long or
extensive depressions, or the presence of connective tissue disorders. 7
Surgical Procedure
The Ravitch procedure was the first widely accepted procedure for treat- Figure 53.8: Markings on the chest wall: lateral transverse incisions
ment of pectus excavatum. As has been described above for pectus cari- perpendicular to midaxillary line, incision for the thoracoport, and the most
elevated point in line with the deepest point of excavatum on the costal ridges.
natum, the cartilages are exposed and removed. The anterior table of the
sternum is divided transversely to flatten the protrusion and the sternum
is stabilized as described for the carinatum, but often with the addition of
a transverse fixation bar, which is removed 6-12 months later.
In the past decade, the minimally invasive repair (MIR), or Nuss
procedure, as described by Dr. Donald Nuss, has become the most
accepted technique for the correction of PE in developed countries. 3,8
The patient is positioned supine with both arms abducted to 70°
to 80° at the shoulder. Prophylactic intravenous antibiotics (e.g.,
cefuroxime) are given. An extensive skin preparation with an alcohol-
based antiseptic solution of the anterior and lateral chest wall is essential.
The distance is measured between the midaxillary points at the
deepest part of the sternal depression. One inch is subtracted from this
measurement to determine the length of the bar. The bar is then bent
symmetrically into a semicircular shape. It is important to have a 2–4
cm flat segment at the centre of the bar to support the sternum. A slight
overcorrection is advisable. 3
The most elevated point in line with the deepest point of excavatum
on the costal ridges is marked (Figure 53.8). Transverse incisions are Figure 53.9: Postoperative chest x-ray showing bar in position.
made across the midaxillary line at the level of the lowest point of the
depression bilaterally. A subcutaneous tunnel is dissected to the top of while the costal margins and flared ribs are pushed down. This corrects
the ridges. A 5-mm thoracoscope is inserted into the interspace inferior the deformity and loosens up the connective tissue around the sternum.
to the proposed site of bar insertion on the right side. A pneumothorax is An umbilical tape is attached to the end of the introducer and
maintained at a pressure of 5 to 7 mm Hg with a flow rate of 1–2 l/min. pulled across the retrosternal space by withdrawing the introducer. The
The rest of the procedure is performed under thoracoscopic visualisation. bent bar is attached to the end of the tape and pulled into the chest,
An introducer is then inserted from the midaxillary incision along the across the mediastinum, and out through the left with the convexity
previously created subcutaneous tunnel, through the marked intercostal facing posteriorly. The bar is then flipped by using bar flippers so that
space (Figure 53.8). This introducer is used to carefully dissect the the convex surface is facing the sternum. This produces an instant
space between the sternum and pericardium under thoracoscopic vision. correction of the depression.
The introducer is brought out through the left symmetrically opposite, A single bar stabiliser is placed on the right side and sutured to
previously marked intercostal space. After passing the introducer through the adjacent muscle with 1/0 polypropylene sutures. In addition, on
to the opposite midaxillary incision, both ends of the introducer are lifted the right side, the bar can be fixed to the adjacent rib with pericostal