question: Which of the following is not true about use of graft in vascular surgery
opa: Autologus saphenous vein achieves superior patency rates to prosthetic materials especially in femorodistal bypass
opb: The patency of the PTFE grafts may be improved by interposition of a vein cuff at proximal anastomosis
opc: Doppler ultrasound assessment is the method of choice for quality assuarance on completion of operative procedure
opd: In the absence of specific contraindications aspirin should be prescribed for all the patients of peripheral vascular disease