This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
Potts surgery: 
Select and explain. 
A. Left pulmonary artery and descending aorta, B. Left pulmonary artery and ascending aorta, C. Main pulmonary artery and aorta, D. Left pulmonary artery and subclavian artery
A: Left pulmonary artery and descending aorta
Answer: A: Left pulmonary artery and descending aorta 
Explanation: Ans. A. Left pulmonary artery and descending aorta Ref: Park's Pediatric Cardiology for Practitioners 6th/ed pl29Explanation1. Classic Blalock-Taussig (BT) shunt, anastomosed between the subclavian artery and the ipsi- lateral PA, is usually performed for infants older than 3 months because the shunt is often thrombozed in young infants.2. Modified BT shunt, a Gore-Tex interposition shunt is placed between the subclavian artery and the ipsilateral PA. This is the most popular procedure for any age. The surgical mortality rate is 1% or less.3. The Waterston shunt, anastomosed between the ascending aorta and the right PA, is no longer performed because of a high incidence of surgical complications.4. The Potts operation, anastomosed between the descending aorta and the left PA, is no longer performed.