Page 151 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

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

There are no significant differences in either postopera- Thoracic wall resection and reconstruction
tive pain or wound complication rates between suture and Thoracic wall tumours
VetBooks.ir significantly faster than orthopaedic wire closure, but Thoracic wall resection is most commonly performed in
wire sternotomy closure. Closure with suture material is
dogs for the management of rib tumours and in cats for
orthopaedic wire closure is recommended for large dogs
because sternal stability and osseous healing are superior.
Closure with orthopaedic wire results in less radiographic the management of injection-site sarcomas. The majority
of rib tumours in dogs are primary malignant sarcomas,
evidence of displacement of sternebrae 28 days post with osteosarcoma (OSA) and chondrosarcoma (CSA)
sternotomy. Furthermore, closure with orthopaedic wire being the two most common rib tumours (Baines et al.,
results in better sternal stability because of chondral or 2002; Liptak et al., 2008b).
osteochondral union between the osteotomized stern- Computed tomography (CT) scans are recommended
ebrae, whereas suture closure only results in fibrous union for both local and distant staging of chest wall tumours.
(Pelsue et al., 2002). Following closure of the sternotomy, Local staging assists in surgical planning by determining
the pectoral muscles, subcutaneous tissue and skin are the size and location of the tumour, the extent of rib
closed routinely in separate layers (Figure 11.5h). The thora- involvement (both the number of ribs and the dorsal and
costomy tube is secured with a Chinese fingertrap suture ventral extent of the tumour), and whether there is adhesion
pattern (Figure 11.5i) and the thoracic cavity is evacuated or invasion of the tumour into adjacent structures such as
to re-establish negative intrathoracic pressure. the lungs, pericardium, sternum and vertebrae (Incarbone
and Pastorino, 2001); however, CT is not always sufficiently
sensitive for differentiating between true adhesion and just
Complications contact. Helical CT scans are significantly more sensitive
Overall, complications are reported in 0–78% of cats and for the detection of metastatic pulmonary lesions than
dogs following median sternotomy. Complications are rare survey radio graphs, and this may be more pertinent in
in cats surviving more than 14 days after surgery (Burton dogs with rib tumours because superimposition of the
and White, 1996), and are more common in cats and dogs lungs by the chest wall mass and pleural effusion can make
with pyothorax (Tattersall and Welsh, 2006). Short-term the detection of pulmonary metastasis difficult (Nemanic et
complications are reported in 19–40% of dogs surviving al., 2006). There is a relatively high incidence of bone
longer than 14 days, including haemorrhage, incisional metastasis in dogs with primary rib OSA (16%) and, similar
seroma, wound infection (Figure 11.6), thoracic limb neuro- to appendicular OSA in dogs (Jankowski et al., 2003),
logical deficits and excessive postoperative pain (Burton whole-body bone scans are recommended for the detec-
and White, 1996; Pelsue et al., 2002; Tattersall and Welsh, tion of occult synchronous or metastatic disease and
2006). Heavier dogs are predisposed to short-term compli- possibly determination of dorsal and ventral surgical
cations, but not long-term complications (Burton and margins for rib resection.
White, 1996). Wound complications are significantly more Preoperative incisional biopsy should be considered if a
likely in dogs treated with a median sternotomy compared knowledge of the tumour type will change the willingness of
with a lateral intercostal thoracotomy (Tattersall and the owner to proceed with surgery, because the prognosis
Welsh, 2006). Long-term complications occur in 22% of is significantly worse for dogs with primary rib OSA (median
dogs and include haemorrhage, sternal fracture, sternal survival times of 90–120 days with surgery alone and
osteomyelitis and delayed wound healing (Burton and 240–290 days with surgery and adjuvant chemotherapy)
White, 1996). Sternal osteomyelitis is the most common than for dogs with primary rib CSA (median survival times
long-term complication and causes sternal discomfort, of 1080 to >3820 days) (Pirkey-Ehrhart et al., 1995; Baines
bilateral thoracic limb lameness, recurrent ventral thoracic et al., 2002; Waltman et al., 2007; Liptak et al., 2008b).
oedema, pyrexia, inappetence and depression. Other
reported complications include unstable sternebrae repair, Chest wall resection
transient iatrogenic chylothorax, incisional oedema and Surgical technique: Surgical excision of rib tumours
incisional dehiscence (Burton and White, 1996). should include one rib cranial and one caudal to the
tumour, 3 cm of grossly normal bone dorsal and ventral
to the tumour in the affected rib(s), and 3 cm lateral
margins around all contiguous soft tissues, including
biopsy tracts, pleura, muscle and fascia (Figure 11.7ab).
Non-involved muscle should be preserved for auto genous
reconstruction. The caudal intercostal thoracotomy inci-
sion should be performed first, one rib caudal to the
tumour based on preoperative imaging, to assist in deter-
mining ventral and dorsal margins (Figure 11.7cd). The
intercostal vessels are ligated dorsally, either indivi dually
or with a heavy-gauge circumcostal ligature (Figure 11.7e).
The internal thoracic artery should be identified and
ligated. The ribs are ostectomized dorsally and ventrally
with bone cutters (Figure 11.7fg), a sagittal saw or an oscil-
lating saw. An oscillating saw is preferred if a partial stern-
ectomy is required to achieve adequate ventral margins
(Figure 11.8). In some human and veterinary reports, exci-
sion of the entire affected rib has been recommended
Short-term complications, such as this wound infection, are for treatment of primary malignant sarcomas because
11.6
reported in up to 40% of cases in dogs following median of intramedullary spread of the tumour (Figure 11.9;
sternotomy. Incarbone and Pastorino, 2001; Halfacree et al., 2007). If

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