For vascular anastomosis sutures of choice -

Ans. is 'a' i.e., Polypropylene Vascular anastomoses:* Vascular anastomoses require an extremely accurate closure as they must be immediately watertight at the end of the operation when the vascular clamps are removed.* In many cases, some form of prosthetic material or graft may be used which will never be integrated into the body tissues and so the integrity of the suture line needs to be permanent.* For this reason, polypropylene is one of the best sutures as it is not biodegradable. It is used in its monofilament form, mounted on an atraumatic, curved, roundbodied needle.* Knot security is important, and as polypropylene is monofilament and the anastomosis often depends on one final knot, several throws (between six and eight) of a well-laid reef knot are required.* The suture line must be regular and watertight with a smooth intimal surface to minimise the risk of thrombosis and embolus, as well as to avoid any leakage.* Suture size depends on vessel calibre: 2/0 is suitable for the aorta, 4/0 for the femoral artery and 6/0 for the popliteal to distal arteries.* Micro vascular anastomoses are made using a loupe and an interrupted suture down to 10/0 size.