Chapter 104 Thoracic Wall Flashcards
Where does the diaphragm originate?
L4
What artery does the thoracodorsal artery arise from?
Subscapular
What type of cartilage connects sternebrae?
Fibrocartilage
TAJ says fibrocartilage, anatomy book says hyaline!
Also TAJ says 9 sternebrae but is 8
Where does the lat dorsi originate and insert?
Origin: last few ribs and thoracodorsail fascia (spinous processes of last few thoracic and lumbar vertebrae)
Insertion: Teres major tuberosity of humerus
What is the origin and insertion of serratus ventralis?
Origin: Transverse processes of last 5 cervical vertebrae and lateral surface of first 7/8 ribs
Insertion: Medial/axial serrated surface of scapula
Label diagram
How many intercostal arteries are there? Where do they arise from?
12 intercosatl arteries (none behind rib 13)
Arise from aorta and internal thoracic arteries (first 3-4 are branches of vertebral artery cf aorta)
Where dothe internal thoracic arteries arise from?
R and L subclavian arteries
Which parts of heart are best acesses via:
Left ICT
Right ICT
Med. Sternotomy
Trans-diaphragmatic
Left ICT: L atrium and ventricle, pulmonary artery
Right ICT: R atrium, vena cavae, azygous,
Med. Sternotomy: R ventricular outflow tract, pulmonary artery (or L ICT)
Transdiaphragmatic: Apex i.e. for epicardial pacemaker
What does V0 refer to (in context of thorax)
V0 is volume of thorax when passive elestic structures of the thoracic wall are relaxed
List the layers incised during 4 ICT
Skin
Sc
Cutaneous trunci
Lat dorsi
Scalenus
Serratus ventralis
(+- lateral edge of deep pectoral)
(+- external abdominal oblique)
External intercostal
Internal intercostal
Pleura
Does rib retraction provide better cranial or caudal exposure
Better cranial exposure
(i.e. if unsure which spoace err on caudal side)
Where does the external abdominal oblique muscle originate?
Origin: Lateral aspect of 4/5- 12th rib and along last rib and thoracolumbar fascia.
What does tobias recommend re sternotomy closure?
PDS in patients <10kg
Sternal wire or 0 PDs if >10kg
Alternating figure of 8 pattern
List 7 possible approaches to the thoracic cavity
- ICT
- MS
- Thoracoscopy
- Transdiaphragmatic
- Paracostal
- Xiphoid resection
- Trans-sternal thoracotomy
Breed ‘predilection’ for pectus excvatum?
Bengal and Burmese
List 3 options for pectus excavatum intervention
- External splint
- Internal splint (VCP secured with PDS reported)
- Osteotomy of sternebrae and costochondral junctions + external splint
In a group of cats with traumatic rib fractures, how many had concurrent intra-thoraci injury?
87%
When is exploratory thoracotomy indicated according to Scheepens bite wound paper (3 factors)?
Rib fractures, pulmonary contusions, pneumothorax
Name a method for stabilisation of multiple rib fractures
Basket weave
List 4 most common thoracic wall neoplasias
- Osteosarcoma
- Chondrosarcoma
- Fibrosarcoma
- STS (haemagiopericytoma, PNST, malignant schwannoma)
Others inc haemangiosarc, MCT,
May see other clinical signs eg chylothorax, BUdd0Chiari like syndrome, lameness
What is reported MST for osteosarcoma following curative intent surgery + chemo
and reported MST chondrosarcoma (?if same paper)?
10 months
Chondrosarcoma 5 years!
What are recommended margins for most thoracic wall tumours?
What is considered upper limit for number of ribs removed?
3cm and one normal ribe either side (can preserve skin if tumour is deep and facial layer between it and skin).
6 ribs max
List 4 muscular flaps used in closure of thoracic wall defects
- Lat dorsi
- External abdominal oblique
- Diaphragm
- Transverse abdominis
- (cadaver study suggests deep pectoral may also be an option)
List 3 types of mesh available for closure of thoracic wall defects
What is reported infection rate with polypropylene mesh?
What is most commonly used biologic graft?
- Polypropylene (Marlex (resists stretching) and Prolene)
- PTFE (sheet so occlusive, strong, expensive)
- Polyglactin (absorbable)
Polypropylene mesh infection rate approx 0-6%
Porcine SI submucosa
