Lung Surgery Flashcards
What are 3 indications for median sternotomies? What should be left in place? How is it closed?
- bilateral thoracic exploration
- cranial mediastinal masses - thymoma
- cranial thoracic trachea - stents at inlet
manubrium and xiphoid
closed figure eight polypropylene sutures or orthopedic wire
What portals are used for minimally invasive thoracoscopies?
intercostal and transdiaphragmatic subxiphoid portals
What is the purpose of a transdiaphragmatic approach to thoracic cavity surgery? In what 3 situations is it utilized?
access to thoracic cavity during celiotomies
- thoracic duct ligation
- surgery of the caudal esophagus
- intra-operative CPR/cardiac massage - less painful than splitting ribs and spares lung of trauma
How are rib resections performed?
ribs can be removed or pivoted at costochondral junction —> cranial movement wider
- rarely required, leave periosteum in place
What are some reasons to leave chest tubes in following thoracic surgery?
- allows for monitoring and removal of air and fluid
- provides access to pleura for infusion of local anesthetics
Where are the left and right lung lobes approached upon pulmonary surgery?
LEFT:
- cranial = L 5th ICS
- caudal = L 7th ICS
RIGHT:
- cranial = R 5th ICS
- middle = R 5th ICS
- caudal = R 7th ICS
lateral thoracotomy!
Why aren’t partial lung lobectomies commonly recommended?
risk of air leaking from suture site = pneumothorax
- never used for neoplasia
- blebs, bullae
What access is required for total lung lobectomies?
access to hilus —> 5th-7th ICS even if neoplasia is present in the caudal periphery
- CT or radiographs can help guide approach
What is a pneumonectomy? When is it indicated?
removal of all lobes of one lung, approached by lateral ICS
diffuse disease through multiple lung lobes - neoplasia, abscess, trauma
What is the maximum lung mass that can be acutely removed without being fatal?
50%
What side of the lungs is the safest to be completely removed?
LEFT
- R has more lobes and vasculature
What kind of stapler is used for complete/partial lung lobectomy? How is it used?
thoracoabdominal stapler (TA)
- isolate hilus of affected lobe or affected portion
- staple entire pedicle (vessels and bronchus) or ensure adequate margins for partial lobectomy
- excise lobe distal to staples
What is a major pro and con to using thoracoabdominal staplers for lung lobectomies?
PRO - decreased anesthesia and surgery time
CON - device too large for small patients
How are partial lung lobectomies performed by hand? What can be done with very small and peripheral masses?
- place clamps proximal to the affected portion of the lobe
- suture proximal to clamps: one or two continuous patters
- excise mass and oversew transection site
guillotine suture
How is a complete lung lobectomy performed by hand?
- triple ligate vessels at the hilus
- pre-place horizontal mattress sutures and tie prior to transection
- oversew transected end of bronchus with a continuous pattern
How can the affected lung tissue be handled to avoid contamination? What should be checked for before closing?
isolate with moistened laparotomy sponges
- hemorrhage
- air leakage
How can air leakage be checked for prior to closing?
fill thoracic cavity with saline and look for bubbles during PPV (25-30 cm H2O)
What is the difference between a pulmonary bleb, bullae, and cyst?
BLEB = localized collection of air between internal and external layer of visceral pleura
BULLAE = non-epithelialized cavities produced by disruption of intra-alveolar septae
CYST = closed sacs lined by epithelium filled with fluid or air
What are cysts, bullae, and blebs commonly secondary to? What 4 complications are associated?
blunt trauma or traumatic rupture of alveoli due to underlying lung disease
- abscessation
- rupture
- spontaneous pneumothorax
- atelectasis
What initial treatment is recommended for cysts, bullae, and blebs? What is recommended if this fails?
conservative - thoracostomy tubes 48-72 hrs
surgical intervention - partial/complete lung lobectomy, pleurodesis (pre-op CT may be helpful in identifying lesions)
How does lung lobe torsion affect the lungs?
- venous and lymphatic congestion
- consolidation
- pleural effusion
What are the most common causes of lung lobe torsion? In what 2 species is this most common?
pleural effusion or partial collapse
- large, deep-chested: Afghan (right middle, left cranial)
- Pugs: left cranial
What clinical signs are associated with lung lobe torsion? What 3 things are seen on physical exam?
acute onset dyspnea, tachycardia, cough, exercise intolerance, or hemoptysis
- pyrexia
- pale MM
- decreased lung sounds ventrally
What is most commonly seen on thoracocentesis in cases of lung lobe torsion? What is rare to see?
serosanguinous or chylous effusion
evidence of sepsis on cytology
What initial treatment is performed in cases of lung lobe torsion? How is it completely treated? What is avoided?
STABILIZATION: thoracocentesis, oxygen supplementation, IV fluids
lung lobectomy - TA stapler
untorsing the lobe - causes the release of cytokines and endotoxins that can cause reperfusion injury
What is required post-op in cases of lung lobe torsion? What is prognosis like?
- thoracic drainage for 3-5 days
- analgesia
- antibiotics
good prognosis for pugs; fair to guarded for other breeds where recurrence is common
What are the most common indications for complete and partial lung lobectomies?
COMPLETE - disease processes that involve the enitre lobe or areas near the hilus, like lung lobe torsion, neoplasia, trauma, contamination, or infection
PARTIAL - focal lesions in the distal lobe not involving major bronchus (still associated with air leakage and not as commonly done)
When are lateral thoracotomies and median sternotomies recommended for lung lobectomies?
LATERAL - removal of one lobe (difficult to remove more than one lobe or examine opposite lung field)
MEDIAN - entire lung field must be examined or when lesions are present in multiple lobes (difficult to remove an entire lobe)
How can large and small leaks in the lung lobes be corrected following a lobectomy?
LARGE - interrupted sutures
SMALL - seal spontaneously within 24-48 hrs, maintain thoracostomy tube
What is associated with spontaneous pneumothorax? In what animals is this most common?
animals with no history of trauma, but history of chronic obstructive lung disease
medium and large dogs
Where do pulmonary blebs develop? Why are they dangerous?
on the surface of the lung
can rupture spontaneously, causing pneumothorax
What initial treatment is recommended for pulmonary blebs What should be done if it does not resolve within 5-7 days?
thoracostomy tube drainage for pneumothorax
exploratory thoracotomy
What surgical treatment is not recommended for pulmonary blebs? Why?
pleurodesis - difficult to achieve complete adhesion of pulmonary and parietal pleura
What is a lung lobe torsion?
rotation of lung lobe on its hilus, resulting in venous congestion, consolidation, and pleural effusion
What are 4 common things seen on history in animals with lung lobe torsion?
- respiratory distress
- anorexia and depression
- previous history of pleural space disease, pneumonia, or trauma
- previous thoracic surgery
What are 2 common clinical findings in patients with lung lobe torsion? What is seen on radiography?
- muffled heart and lung sounds
- hydrothorax (pseudochylothorax)
opacity of affected lobe, most commonly the right middle (left cranial in pugs)
What is the recommended treatment for lung lobe torsion? What are 2 reasons?
total lobectomy without untwisting the hilus (prevents reperfusion injury)
- extensive adhesions and edema make it difficult to return lung to normal position
- rapid necrosis secondary to venous congestion occurs quickly
What should be done if dyspnea or persistence of effusion occurs following lung lobe torsion treatment?
radiograph to rule out torsion of a second lung lobe
What is avoided when inducing a patient with respiratory distress?
oxygen mask or chamber = adds to distress
(don’t wait, intubate!)
What is a common sign of pneumothorax on radiographs?
- elevated heart from sternum
- lungs retracted from body wall
What are the most common pulmonary neoplasias?
bronchogenic carcinoma (primary)
- metastasis common!!
What are the 2 most common chest wall neoplasias?
- osteosarcoma
- chondrosarcoma
What is the pathophysiology of pneumothorax?
- air accumulates in the pleural cavity, leading to loss of normal negative pleural pressure
- lungs undergo elastic recoil and collapse
What treatments are recommended for mild, moderate, and severe pneumothorax?
MILD - no severe hyperventilation, hypoxemia, or respiratory acidosis = cage rest and observation
MOD - respiratory distress = thoracocentesis, thoracostomy tube with recurrence
SEVERE - marked respiratory distress = tube thoracostomy with continous suction drainage, exploratory thoracotomy if leakage is significant and persists 5-7 days
What is the most common cause of open pneumothroax?
impalement
- bite/stab/gunshot wounds, inadequate thoracotomy closure
What causes pneumomediastinum?
esophageal or tracheal perforation
- can burst and progress to pneumothorax
What is the size difference between bullae and blebs?
bullae = > 1 cm
blebs = < 1 cm
