Page 158 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 11 · Thoracic wall anatomy and surgical approaches

has ideal characteristics; however, it is very expensive. Wound problems are the most common complications
Marlex and Prolene meshes, whilst not impervious to air following chest wall resection in dogs. Incisional seromas
VetBooks.ir reconstruction (Incarbone and Pastorino, 2001). because of the aggressive resection and the amount of
are reported in up to 40% of dogs; seromas are common
and fluids, are just as effective as PTFE for chest wall
When performing chest wall reconstruction, the size of
dead space following reconstruction. Seroma formation
the prosthetic mesh is tailored to the size of the chest wall
defect so that the edges are doubled over to provide a may also indicate partial failure of the latissimus dorsi
muscle flap, and distal flap necrosis should be suspected
double layer for suturing to adjacent host tissue. The mesh if the seroma does not resolve spontaneously within 2
is sutured under mild tension to either the pleural or the weeks (Liptak et al., 2008a). The incidence of incisional
lateral surface of the defect using either absorbable or seromas may be decreased with the use of either active or
non-absorbable monofilament suture material (Figure passive drains, and bandaging the chest postoperatively.
11.19). If possible, the mesh should be sutured to the ribs. Early wound infection, incisional wound dehiscence and
Although it is rarely required, prosthetic mesh can be muscle flap necrosis and failure are rare (Figure 11.20).
supported with autogenous split rib grafts, allogeneic free Some surgeons avoid the use of non-absorbable
rib grafts or plastic spinal plates between the ends of the meshes because of the perception that the risk of infection
resected ribs following extensive resections. If a compo- is increased with prosthetic material. However, Marlex
site reconstruction is planned, then omental pedicle grafts mesh is considered an ideal material for chest wall recon-
should cover the pleural surface of the mesh and auto- struction partly because of its resistance to infections and
genous muscle flaps should be sutured over the lateral this is supported by retrospective clinical studies in dogs
surface of the mesh (see Figure 11.16). and humans, which show that prosthetic meshes used for
chest wall reconstruction are associated with very low
rates of infection. Infection rates of 0% and 2.3% have
been reported in two retrospective studies with long-term
follow-up of chest wall reconstruction with prosthetic
mesh (Liptak et al., 2008a). The majority of these infections
are deep seated and they usually occur late in the post-
operative period, with infection reported in one dog 767
days postoperatively (Liptak et al., 2008a). In humans,
infected meshes are managed with surgical removal and
culture-directed antimicrobial therapy. Fibrous ingrowth
into Marlex mesh results in a stable fibrous wall within 6
weeks, and removal of the mesh does not compromise the
integrity or strength of the reconstructed chest wall
(Skoracki and Chang, 2006).

Prosthetic polypropylene (Marlex) mesh has been used to
11.19
reconstruct a chest wall defect following resection of a
primary rib osteosarcoma. The edges of the mesh are doubled over and
sutured to the chest wall defect using either an interrupted (depicted) or
continuous suture pattern under mild tension.

Complications: Complications following chest wall resec-
tion and reconstruction are reported in up to 50% of dogs;
however, the majority of these complications are minor
and require no to minimal intervention. Respiratory compli-
cations are common in humans and include prolonged
mechanical ventilation, pneumonia, acute respiratory
distress syndrome and pulmonary hypofunction. In
contrast, respiratory complications are very rare in dogs
(Halfacree et al., 2007; Liptak et al., 2008a). Pulmonary
function is normal, respiratory pattern and blood gas
analyses are typical of dogs treated with any type of open-
chest surgical pro cedure (including thoracotomy), and no
dog has been reported to require postoperative mechan-
ical ventilation following chest wall resection and recon-
struction (Halfacree et al., 2007; Liptak et al., 2008a).
Paradoxical motion of the reconstructed chest wall is com-
mon for 3–7 days post surgery, but paradoxical motion in
the absence of under ying pulmonary trauma does not
l
result in pulmonary hypofunction in dogs in either experi-
mental or clinical studies (Halfacree et al., 2007; Liptak
et al., 2008a). As a result, more rigid chest wall reconstruc-
tion techniques, such as mesh–methylmethacrylate sand-
wiches and rib replacement with spinal Lubra plates, are istal necrosis of a latissimus dorsi L muscle flap resulting
probably unnecessary. 11.20 in a chest wall defect (arrowed).

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