CV surgery Flashcards
How many rib pairs are there in the dog and cat?
13
What needs to be avoided during surgical approach of the heart?
neurovascular bundle caudal to each adjacent rib
What are the different thoracic surgical approaches?
- lateral thoracotomy (intercostal most common)
- median sternotomy
- transsternal
- thoracoscopy (minimally invasive)
Most conditions require which approach to the heart?
left approach
PDA, persistent right aortic arch, pulmonic valve) (between ribs 4 and 5
What is a patent ductus arteriosus (PDA)?
- failure of closure of normal embryonic ductus arteriosus after birth
- blood shunts from high to low pressure system
What are the hemodynamic effects of PDA?
- blood recirculated to right heart/lungs and back to left ventricle
- over-circulation of lungs
- LV hypertrophy
- RA dilation can lead to atrial fibrillation
What are the clinical signs of PDA?
- exercise intolerance
- dyspnea
- stunted growth
- machinery murmur
- hyperkinetic pulse
What is the objective of surgery for PDA?
occlusion of patent ductus
What are some preoperative considerations for PDA surgery?
- detect right to left shunting
- evaluate for concurrent congenital abnormalities
- treat for preexisting sequelae
- administer fluids with caution
- pain management
- anesthesia
When should surgery be performed for PDA?
- sooner diagnosis if patient is asymptomatic
- if symptomatic, treat accordingly prior to anesthesia
How is surgery performed for PDA?
- left fourth intercostal thoracotomy
- PDA located between aorta and pulmonary artery
- dissect around PDA and ligate with silk suture
- be sure to dissect dorsally to ventrally on right side of aorta
What kind of suture is used to ligate a PDA?
circumferential suture (pulled up against the medial aspect of PDA from behind aorta)
What is the prognosis for PDA?
excellent if performed at early stage
What are some complications of PDA surgery?
- hemorrhage
- recanalization
What are vascular ring anomalies?
- congenital malformation of the aortic arch system
- results in entrapment and constriction of esophagus
- most common is persistent right aortic arch (PRAA)
What are the clinical signs of PRAA?
- persistent regurgitation
- aspiration pneumonia
- thin, emaciated animal
(all signs associated with megaesophagus)
What is seen in radiographs of PRAA?
- esophageal dilation
- ventral tracheal displacement
- wide mediastinum
- aspiration pneumonia
What is the goal of PRAA surgery?
relieve esophageal constriction by transecting the ligamentum arteriosum
What is the surgical approach for PRAA?
left fourth intercostal thoracotomy
How is surgery performed for PRAA?
- ligamentum arteriosum located between aorta and pulmonary trunk
- dissected free
- transected
What is an important complication of PRAA surgery?
persistent megaesophagus
What is involved with postoperative care following PRAA surgery?
- elevated feedings
- small, frequent meals
- monitor for aspiration pneumonia
- gradually begin feeding normally after 2 weeks
What is pericardial effusion?
fluid within pericardial sac causes cardiac tamponade
How do you diagnose pericardial effusion?
- clinical signs associated with tamponade
- electrical alternanes on ECG
- globoid cardiac silhouette
- pericardiocentesis
