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336 Chest Wall Deformities
Surgical Procedure
The aim of surgery is to expand the chest wall and increase the thoracic
volume, allowing lung expansion. Multiple surgical procedures have
been described. Using a median sternotomy, the two halves of the
sternum are stented apart by using rib drafts or methyl methacrylate.
Another option is dividing the ribs laterally in a staggered arrangement.
The divided ribs are then fixed by using titanium plates. This allows for
gradual chest expansion. Recently, a form of expansion thoracoplasty
by using a vertical expandable prosthetic titanium rib (VEPTR) has
shown encouraging results. It allows for serial expansion of the thoracic
wall. Despite these techniques, patients have only a modest improve-
ment in respiratory function. The mortality from this condition still
remains high. 11
Sternal Cleft
Introduction
Sternal clefts result from failure of fusion of the mesenchymal plate
during the eighth embryonic week. The defect can be partial (superior
Figure 53.11: Superior sternal U cleft deformity in a neonate.
or inferior) or complete. These rare abnormalities represent 0.15% of
12
all chest wall anomalies.
The superior clefts consist of a U-shaped sternum with a bridge
connecting both halves of the sternum inferiorly (Figure ). There may
be a scar on the overlying skin with varying degrees of herniation of the
great vessels or heart. The inferior cleft consists of an inverted-V defect
with a midline cord-like scar running inferiorly to the umbilicus (Figure
53.12). Inferior clefts may also form part of the pentalogy of Cantrell.
Cardiac pulsation may be seen through the defect. The complete cleft
consists of two separated sternal bars. There is an association with
congenital heart disease and craniofacial haemangioma.
Preoperative investigations should include ECG, echocardiogram, and
a three-dimensional (3D) CT scan for complex defects (Figure 53.13).
Surgical Procedure
The aim of surgery is to provide protection for the mediastinum by
bridging the defect. This also stops the paradoxical mediastinal move-
ment with respiration and improves cosmetic appearance. The surgi-
cal procedure employed depends on the age of the patient. Surgical
correction in the neonatal period is now preferred, as the chest wall is
13
more compliant, allowing for primary closure of the defect. Access
to the sternal bars is obtained by a midline incision and mobilisation Figure 53.12: Inferior sternal cleft with diverification of recti and umbilical hernia.
of the skin and subcutaneous tissue flaps. The medial insertions of the
pectoralis major and rectus abdominis are mobilised and reflected. The
medial perichondrium or periosteum is mobilised and approximated.
For a neonatal repair of the superior sternal cleft, the inferior
sternal bridge is excised converting it to a complete cleft. Multiple
lengths of polydioxanone (PDS) sutures are then placed around both
sternal bars. The sutures are then tied one at a time from inferior to
superior. Collaboration with the anaesthetist is essential at this time,
as respiratory compromise may occur. A retrosternal drain is inserted,
the rectus and pectoralis muscles are reattached, and the subcutaneous
tissues and skin are closed. 14
Older patients, due to a less compliant chest wall, require bridging
the defect with autologous bone or artificial mesh. The defect is
bridged by using a cancellous bone graft from the iliac crest or split
rib grafts. 12,13 For wider defects, a combination of transverse rib struts
covered by synthetic mesh can be used. 12 Figure 53.13: Three-dimensional CT scan of a 9-year-old girl with a complete
The long-term outcomes following sternal reconstruction are good. sternal cleft repaired with a cancellous free bone graft from her iliac crest, with a
Some patients may develop mild pectus excavatum, however. 12 very good result. 13
Evidence-Based Research
Table 53.2 presents a large series (303 patients) by an expert in pectus
excavatum repair.