surgical approaches to thorax in small animals
TRANSCRIPT
Thoracotomy
surgical incision of the chest wall.
SURGICAL ANATOMYThe thoracic cavity of dogs n cats are compressed laterally so greatest dimension is DV.
Intercostalisexternus
Rectusabdominis
Obliquus externusabdominis
Rectusthoracis
Scalenusdorsalis
Serratusventralis,
Serratus dorsalis cranialisObliquus internusabdominis
Serratus dorsaliscaudalisLongissimus
thoracis
Levator costae
Intercostalis internus
Intercostalisexternus
SURGICAL APPROACHES
Intercostal Thoracotomy
Rib Resection Thoracotomy
Median Sternotomy
Transsternal Thoracotomy
Special Considerations: In animals with respiratory dysfunction, oxygen may be
administered.
All animals with open chest cavities require intermittent positive pressure ventilation (including those with diaphragmatic hernias).
High ventilatory pressures should be avoided in patients with chronically collapsed lung lobes, pneumonia.
Thoracotomy procedures often cause substantial pain, and postoperative analgesic therapy is indicated.
Intercostal Thoracotomy
Standard approach
Excellent access to immediate structures
Complications – uncommon, if airtight closure
3rd to 10th ICS
Lateral radiograph
Finochietto retractors
THORACIC STRUCTURE LEFT RIGHT
Heart and Pericardium
PDA, Persistent Rt Aortic Arch
Pulmonic Valve
4,5
4 (5)
4
4,5
Lungs
Cranial lobe
Intermediate lobe
Caudal lobe
4-6
(4) 5
5 (6)
4-6
(4) 5
5
5 (6)
EsophagusCranial
Caudal 7-9
3,4
7-9
Caudal Venacava (6-7) 7-9
Thoracic DuctDogCat
(8-10)
8-10
8-10
(8-10)
Thoracostomy Tube PlacementMake an incision overthe dorsal third of the intercostalspace.
Tunnel the tube withtrocar - tipped stylet cranioventrally
Tilt the tube perpendicularto the thoracic wall, Hit the end of the tubeto pop it through the intercostal spaceand pleura
advance the tubecranially into the thorax
Clamp the tube once thestylet is partially retracted
Adjust the tube position sothat the tip is at the level of the secondintercostal space before securing it inplace.
Lateral Rib Resection Thoracotomy
A wider exposure of the chest (eg : removal of large masses)
Increased time & less secure closure
Infrequently used in small animals
Median Sternotomy
Entire thorax view
Spontaneous pneumothorax /pericardiectomy/ exploratory thoracotomy
Access to dorsal thoracic cavity is limited
Oscillating bone saw/ chisel/ osteotome
Transsternal Thoracotomy IC thoracotomy extended through sternum and
continued to other side’s ICS
Extensive exposure of specific region
Infrequently used
7th ICS - DH
1. PECTUS EXCAVATUM Inward concave deformation of caudal sternum and
costal cartilages
Retarded growth, dyspnoea, exercise intolerance, vomiting, cyanosis
Sx indicated if Cardio pulmonary effect is v severe
Multiple chondrotomy, excision of malformed costal cartilages, sternum struts, external splinting
2. RIB DEFORMITIES Missing ribs
Fused ribs
Multiple ribs
Malformed Ribs
Sx –if restricted ventilation & paradoxical respiration
3. METABOLIC BONE DISEASES Primary parathyroidism
Hypervitaminosis
Cartilage exostosis
Tx: According to underlying cause
4. INFECTION Bite, lacerations, FB Infection. Check pyothorax
before tx.
Tx: Drainage, Debridement
Osteomyelitis Partial sternectomy
FB Fistulous tract Contrast fistulogram excision
5. TRAUMA Internal injury!
Tx: Small wounds: standard
Open wound upto pleura seal with petroleum based gauze
Open chest wound pleural evacuation & stabilisation
IC muscle rupture -> closure like thoracotomy
IC vessel rupture
Simple non displaced rib # - rest & chest bandage
Unstable rib # : Internal fixation
Flail Chest : stabilisation, circumcostal suture, splint
6. NEOPLASIA Skin / sc benign , lipomas
Osteosarcoma, chondrosarcoma, fibro sarcoma, haemangiosarcoma
Internal thoracic wall –considered malignant
Neoplasms of rib – Primary malignant
Dx- Radiograph – osteolysis, extra thoracic soft tissue masses, mineralization, biopsy
Tx: Resection. Prognosis poor for osteosarcoma