RT Book, Section A1 Doherty, Gerard M. SR Print(0) ID 58098908 T1 Pulmonary Atresia T2 Quick Answers Surgery YR 2010 FD 2010 PB The McGraw-Hill Companies PP New York, NY SN LK accesssurgery.mhmedical.com/content.aspx?aid=58098908 RD 2024/10/04 AB • A congenital heart lesion that decreases pulmonary arterial blood flow resulting in a right-to-left shunt• Cyanosis and decreased oxygen delivery causes compensatory polycythemia (Hct > 70%) and spontaneous thrombosis• Exercise, acidosis, pain worsens cyanosis, can cause hypoxic spells• Squatting increases systemic resistance, causing increased pulmonary flow and oxygen• β-Blockers (decreases spasm), fluid intake, HCO3 administration, norepinephrine (increases systemic resistance) may help decrease hypoxia• Clubbing due to proliferation of capillaries and AV fistulas in extremities• Bronchial and mediastinal arteries enlarge• Ductus arteriosus maintains flow to lungs during fetal development• Alprostadil early can allow time for optimization before definitive treatment• Operative options to increase pulmonary flow: -Blalock-Taussig shunt: Subclavian artery to ipsilateral pulmonary artery (PA) end to side fashion-Modified Blalock-Taussig shunt: Subclavian to PA using PTFE-Glenn: Superior vena cava (SVC) to PA shunt -Fontan: SVC and inferior vena cava (IVC) rerouted to PA-Excision of obstructive muscle, patch enlargement of infundibulum, and valve replacement• Pulmonary valve replaced by diaphragm of tissue, causing obstruction• PA normal size• Atrial septal defect (ASD) or patent ductus arteriosus (PDA) necessary for survival after first few hours of birth• RV and tricuspid annulus typically small• RV: Coronary artery fistulas and coronary artery stenoses are common• Some coronary flow dependent on increased pressures in RV