Thoracic Surgery Flashcards
most common surgical approach of thorax
lateral thoracotomy
what procedure is seen here
lateral/intercostal thoracotomy
less painful than median sternotomy
how is a lateral thoracotomy closed
circumcostal sutures
indications for median sternotomy
bilateral thoracic exploration
cranial mediastinal masses
cranial thoracic trachea
what should be left intact with median sternotomy
manubrium or xiphoid
can cut both if necessary - be extra careful when closing
minimally invasive approaches
used with lateral approach only
thoracoscopy
video assisted
special considerations for thoracic surgery
positive pressure ventilation
chest tube(s) commonly required post op
24 hour post op monitoring
what is a pneumonectomy
removal of all lobes of one lung
rarely performed, indicated for cases where disease is diffuse through multiple lung lobes (neoplasia, abcess, trauma, infiltrative inflammatory disease)
total lung lobectomy vs partial lobectomy
depends on disease process and location of lesion within the lobe
suture technique for partial lobectomy
suture proximal to clamps - 1-2 rows or continuous suture pattern
guillotine suture may be used for biopsies and very small peripheral masses
suture technique for complete lobectomy
triple ligation of vessels - cut between middle and distal ligatures
pre-place horzontal mattress sutures and tie prior to transection
oversew transected end of bronchus
advantages of stapling technique for partial/complete lobectomy
decreased anesthesia and surgery time
disadvantage to stapling technique for partial/complete lobectomy
standard devices too large for very small patients
prior to closure of pulmonary surgery
check for:
bleeding/hemorrhage
air leakage
chest tube placed vis separate intercostal incision
surgical diseases of pulmonary parenchyma
spontaneous pheumothorax
bronchoesophageal fistulas
lung lobe consolidation and abscessation
bronchiectasis
lung lobe lacerations
lung lobe torsions
neoplasia
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 (often secondary to pulmonary contusions)
cysts, bullae, and blebs
can be secondary to blunt trauma (cysts) or traumatic rupture of alveoli secondary to underlying lung disease
complications or cysts, bullae and blebs
abscessation
rupture
spontaneous pneumothorax (atelectasis)
conservative treatment of cysts, bullae and bleds consists of
thoracostomy tubes for 48-72hrs
high recurrence rate
when is surgical intervention recommended for cysts, bullae, and blebs
when medical management has failed
pre-op CT may be helpful in ID-ing lesions; partial or complete lung lobectomy, pleurodesis?
what breed is the poster child for lung lobe torsion
afgans
- large, deep chested dogs and pugs are most commonly affected*
- large dogs: right middle or left cranial lung lobe*
- pugs: left cranial lung lobes*
clinical signs of lung lobe torsion
acute onset
dsypnea, tachycardia, C+, exercise, intolerance, hemoptysis
pyrexia, pale mm, decreased lung sounds ventrally on PE
diagnostics for lung lobe torsion
thoracocentesis - serosanguinous or chylous effusion
imaging - rads or CT
T/F surgical treatment of lung lobe torsion includes untorsing the lobe
False
DO NOT untorse lung, avoid release of cytokines and endotoxins - REPERFUSION INJURY!
what is the initial treatment at patient stabilization
thoracocentesis
O2 supplementation
IV fluids
post op care for lung lobe torsion
thoracic drainage for 3-5 days
analgesia and antibiotics
T/F the prognosis for pugs with lung lobe torsion is fair to guarded while other breeds have a good prognosis
False
- good prognosis for pugs, fair to guarded for other breeds*
- 50-61% survival rate, second torsion can occur*
survival with primary pulmonary neoplasia is associated with
lack of LN involvement
location
size of mass
lack of clinical signs
most common type of primary pulmonary neoplasia
bronchiolar or alveolar carcinoma
what is the most common cause of thoracic wall trauma
hit by car
most thoracic wall truama requires surgical intervention
false
what should be done before removing a penetrating chest wound
radiographs or CT
thoracotomy for removal of object
what is flail chest
multiple segemental rib fractures
flail segment moves paradoxically with shest wall during respiration
why do you see hypoxemia with flail chest
hypoventilation secondary to pain
V/Q mismatch secondary to pulminary contusions
what is the most common cause of chylothorax
idiopathic
what is a posible long term consequence of chylothorax
fibrosing pleuritis
what is the treatment for idiopathic chylothorax
surgical
- thoracic duct ligation*
- cysterna chyli ablation*
- subtotal pericardectomy*
- +/- omentalization, pleuralpport placement*
what can be done to improve visualization of lymphatic structures
injection of methylene blue into mesenteric LN
surgical correction of thoracic duct ligation
cats: L 10th ICS
dogs: R 10th ICS
transdiaphragmatic approach, dorsal to aorta ventral to sympathetic trunk, ligation/clip individual branches or perform en bloc ligation
ligate/ clip as close to diaphragm as possible
what is performed with thoracic duct ligation to maximaize success of surgery
subtotal pericardectomy
what can be done with a TD ligation or TD ligation + pericardectomy
cisterna chyli ablation
cisterna chyli ablation results in
re-routing of abdominal lymphatic drainage to major abdominal vessles
dogs have a ______outcome compares to cats
improved
~ 80-90% effusion free > 15 months post-op
what is the most common cause of diaphragmatic hernia
trauma
acute diaphragmatic hernia presentation
respiratory distress (tachypnea, dyspnea, cyanosis)
shock
other injusies may be present (fractures, wounds, etc)
chronic presentation of diagraphmatic hernias
respiratory and GI signs most common
dyspnea, exercise intollerance, lethargy
V+, regurgitation, inappetance
pleural/peritoneal effusion
what is the most accurate diagnostic imaging modality for diagnosing diaphragmatic hernias
Ultrasound (93% accurate)
rads - 66% accurate
when is surgery emergent with diaphragmatic hernias
if the stomach is herniated
complications with diaphragmatic herniorrhaphy
re-expansion pulmonary edema - close control of PPV during Sx is nesscesary! associated with rapid expansion of perviously atelectic lung
persistent pneumothorax
hemorrhage
failure of repair and re-herniation
loss of domain
prognosis for diaphragmatic hernia
excellent if patient survive 24 hours post-op
peritoneopericardial diaphragmatic hernia (PPDH)
congenital communication between pericardium and peritoneal cavity
commonly associated with other congenital defects
presentation of PPDH
may be incidental finding
presentation at middle age
signs can be respiratory, GI, cardiac or neurologic system
breeds predisposed to PPDH
weimaraners
cocker spaniels
DLHs
Himalayans
pentology of defects: congential cranial abdominal wall and diaphragmatic defects
cranial abdominal wall defect
caudal sternal fusion defect
pericardial defect
diaphragmatic defect
intracardial defects (VSD most common)
breeds predisposed to pentalogy of defects
cocker spaniels
weimeraners
dachshunds
collies
exam findings with pentology defects
muffled heart sounds
ascites
murmur
+/- concurrent ventral abdominal wall defect
radiographic findings with PPDH
enlarged cardiac silhouette
dorsal elevation of trachea
overlap of heart and diaphragmatic hernias
gas filled structures in pericardial sac
sternal defects
when should surgery be performed with PPDH
ASAP - between 8-16 weeks ideally
T/F the pericardial sac should be closed separately with PPDH repair
False
does not need to be closed separately - use simple continuous pattern
what is the most common congenital cardiac defect in dogs
patent ductus arteriosus
a patent ductus arteriosus is present when the ductus remains patent _______ after parturition
> 3 days
PDA shunts bood from _____ to _____ side of the heart
PDA shunts bood from left to right side of the heart
severe volume overload of L heart that progresses to left sided failure
what is a reverse PDA
Eisenmenger’s syndrome
right to left shunting, occurs in face of severe pulmonary hypertension
what clinical signs can be seen with reverse PDA
differential cyanosis
exercise intollerance
pelvic limb collapse
polycythemia
PE findings with PDA
continuous murmur
hyperkinetic pulses (BB shot, waterhammer)
+/- stunted growth
T/F occluding of the defect is recommended in all PDA cases because most die before 1 year if not treated
False
occluding of R→L shunting is contraindicated
complications with surgical ligation of PDA
severe hemorrhage secondary to PDA rupture
bradycardia (branham reflex)
residual ductal flow
long term: recanalization
prognosis for PDA
excellant for animals < 6 months at time of surgery
poor to grave for reverse PDA
what is the most common cardiac neoplasia in dogs
HSA of right auricle
which course of treatment offers the best prognosis with right auricular HSA
excision of right auricular mass
followed by pericardiectomy followed by chemotherapy
thickening of pericardium or rapid raise in pericardial pressure results in _______
cardiac tamponade
pericardial diseases
pericardial rupture and secondary pericardial contraction and scarring
pericardial effusion
comstrictive pericarditis
PE findings with pericardial disease
muffled heart sounds
weak femoral pulses +/- pulsus paridoxicus
+/- cardiogenic shock
diagnostics for pericardial disease
thoracic imaging
complete database
electrocardiogram
pericardiocentesis
+/- abdominal imaging
T/F pericardectomy can be curative or palliative depending on underlying disease process
True
what is the most common type of PRAA
PRAA with left ligamentum arteriosum
what is the most common breed with PRAA
german shepards
diagnosed via imaging between 2-6 months of age
what do you have to be aware of when isolating ligamentum arteriosum
dont penetrate the esophagus!
