Ch 104 - Thoracic wall Flashcards
What flaps can be based on the thoracodorsal artery?
- Thoracodorsal axial pattern flap
- Composite musculocutaneous flap incorporating latissimus dorsi
What muscle attaches to the manubrium?
Sternocephalicus muscle
What can be used as landmarks during an intercostal thoracotomy?
- Ribs - finger can be placed uder latissimus to count back from first rib
- Scalenus - attaches cranially to the 5th rib
What muscle is a landmark for the internal thoracic artery?
Transverse thoracic muscle (travels dorsal to muscle)
How many intercostal arteries are present?
12 (ribs 1-12)
Where do the internal thoracic arteries arise from?
Left and right subclavian arteries
What structures can be damaged during a cranial median sternotomy?
- The brachiocephalic truncks and cranial vena cava (Sit right below the sternum and can become collapse during retraction resembling connective tissue)
- Brachiocephalic trunks form from the internal jugular vein and brachial vein. Brachiocephalic trunks then combine to form cranial vena cava in cranial mediastinum
What form of intercostal thoracotomy closure has been associated with less post-op pain?
- Transcostal suture rather than circumcostal
List options for approaching the thorax
- Intercostal thoracotomy
- Rib resection thoracotomy
- Median sternotomy
- Xiphoid resection thoracotomy
- Transsternal thoracotomy
- Transdiaphragmatic thoracotomy
- Paracostal approach
- Thoracoscopy
What vessels will be encountered during approach for a median sternotomy?
- Perforating branches of the internal thoracic artery and vein when seperating the pectoral muscles
What instruments can be used to perform a median sternotomy?
- Reciprocating saw
- Osteotome
- Special sternal saw
- Sternal splitter
- Bone cutters
Where are the sternal LNs located?
Where the internal thoracic arteries meet the transverse thoracic muscle
Why is an alternating figure-of-8 pattern beneficial for closure of the sternum?
- Avoids distraction of the dorsal or ventral edge
- Maximises boney contact
- Reduces pain
- Facilitates healing
What vessels may bleed during a transdiaphragmatic thoracotomy?
Branches of the phrenic artery
What can the paracostal approach be used for?
- Right sided for accessing thoracic duct, cisterna chyli and aorta
- Adrenalectomy
- Migrating FBs for abdominal and thoracic exploration
What are the 2 broad options for thoracoscopy?
- Intercostal
- Paraxyphoid
What breeds are predisposed to pectus excavatum?
- Burmese and Bengal cats
Sternum and caudal ribs fail to grow normally, possible due to shortened or hypoplastic diaphragm, resulting in concave abnormality of the caudal sternebrae
How is pectus excavatum treated?
- External splinting in young animal with compliant sternebrae
- Older animals may need an internal splint (VCP) or osteotomy of deformed sternebrae and costochondral junctions with external splinting
In what breed has a sternal cleft been described?
Along with what other congenital defects?
- GSD
- With PPDH and cranial abdominal hernia
What is a “step” sign on TFAST?
Indicates a discontinuity of the parietal pleura.
Can signify intercostal muscle tear or rib fracture
In what animals with thoracic bite wounds should surgery be recommended?
All those with rib fractures, pulm contusion or pneumothorax (according to a study)
Ongoing haemorrhage, pneumothorax or sepsis are indications for surgical exploration
How can multiple laceration of the intercostal muscles be apposed?
Basket-weave pattern
List the most common thoracic wall neoplasias
- Chondrosarcoma
- OSA
- FSA
- Other spindle cell tumours (haemangiopericytoma, PNST, Schwannoma)
- HSA infrequent
- MST
What are the recommended margins for thoracic wall tumours?
At least 3cm
What is considered the maximum thoracic wall resection for adequate reconstruction?
6 ribs
List options for sternal reconstruction
- Deep pectoral muscle flaps
- Sanwiches of mesh and PMMA
- Kiel bone
What muscle flaps can be used for thoracic wall reconstruction?
- Latissimus dorsi
- External abdominal oblique
- Transversus abdominis
- Diaphragmatic advancement (ribs 8-13) (may require caudal lung lobectomy)
List options for reconstruction with commercial products
- Polypropylene mesh
- PTFE mesh/sheet ($$, strong and occlusive)
- Polyglactin mesh (absorbable, good for infected sites)
- Porcine SIS
Infection rates with polypropylene mesh 0-5.7%. Can be minimised by covering with well vascularised tissue (omentum, muscle)
How often should the thoracostomy tube be suctioned in the post-op period?
When is pleural effusion most common after thoracic wall reconstruction?
- Suctioned every hour until 3 consecutive negative results have been obtained. Then every 4 hours for 12 hours
- Pleural effusion after reconstruction within forst 48hr and then declines sharply within 4-5 days
