Page 157 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery

volume for lung expansion following diaphragmatic Non-absorbable polypropylene mesh (Marlex) is the
advancement (Figure 11.18). The resultant abdominal wall most commonly used mesh for chest wall reconstruction
VetBooks.ir autogenous muscle flaps (e.g. latissimus dorsi and/or Vicryl meshes are also used in humans (Skoracki
defect can be repaired primarily, or reconstructed with
in dogs, but Prolene, polytetrafluoroethylene (PTFE), and
and Chang, 2006). The ideal material characteristics for
external abdominal oblique muscle flaps) or prosthetic
chest wall reconstruction include rigidity, malleability,
mesh (see Figure 11.16).
inertness, radiolucency and resistance to infection. Marlex
Prosthetic mesh: Prosthetic meshes are commonly used mesh is constructed of knitted non-absorbable monofila-
to reconstruct chest wall defects, either alone or in com- ment polypropylene; it has a high tensile strength and
bination with muscle flaps and/or omental pedicle flaps. low perme ability to liquids and gases. The pore size of
Composite autogenous–prosthetic reconstruction tech- 200–800 µm permits rapid ingrowth of vascularized tissue
niques are used if the chest wall defect is too large to be and, by 6 weeks, Marlex mesh is infiltrated with 3–4 mm
reconstructed with an autogenous muscle flap alone or to thick fibrous tissue (Trostle and Rosin, 1994); by 6 months
decrease the perceived risks of complications associated it is incorporated, with no loss of tensile strength or frag-
with prosthetic meshes, such as infection (see Figure mentation. Prolene mesh is often preferred to Marlex mesh
11.14bc). Prosthetic meshes are used for reconstruction in humans, despite both being constructed from polypro-
of larger chest wall defects in humans because they pylene, because Prolene mesh is constructed from
provide additional rigidity when sutured under tension double-knitted polypropylene and thus resists stretching in
and as a result are associated with a significantly all directions. Vicryl is an absorbable mesh and is indi-
decreased rate of respiratory complications and shorter cated for reconstruction of contaminated wounds
hospital stays when compared with autogenous muscle (Skoracki and Chang, 2006). PTFE is strong, resistant to
flap reconstructions (Losken et al., 2004). infection and impervious to air and fluids, and therefore

(a) (b)

(c) (d)
(a) A chest wall defect following resection of seven ribs (ribs 7–13) for excision of an injection-site sarcoma in a cat. The diaphragm will be
11.18
advanced to reconstruct the thoracic cavity, but it is likely that diaphragmatic advancement will decrease intrathoracic volume and restrict
lung expansion, resulting in hypoxaemia and respiratory distress. In these cases, lobectomy of the caudal lung lobe should be considered. (b) A caudal
lung lobectomy is being performed ith a thoracoabdominal stapler to permit su cient intrathoracic volume for normal e pansion of the remaining
lung lobes follo ing diaphragmatic advancement. c Follo ing caudal lung lobectomy there is su cient intrathoracic volume for normal e pansion of
the remaining lung lobes. (d) The diaphragm is being advanced to restore normal thoracic function and physiology. Note the temporary thoracostomy
tube hich is used to evacuate air and fluid from the thoracic cavity intraoperatively and is removed once negative intrathoracic pressure has been
established. The resultant abdominal wall defect is then reconstructed using autogenous and/or prosthetic techniques (see Figure 11.16).

148

Ch11 HNT.indd 148 31/08/2018 11:52