<prompt> The most common cause of acquired aeriovenous fistula isBacterial infectionFungal infectionBlunt traumaPenetrating trauma  <response>: . Trauma is the most common cause of accquired atreiovenous fistulaAV fistula.most common sites involved are femoral region,brachial region,popliteal region,wrist,aoa-vena canal,abdomen.It may be following road traffic accidents,penetrating wounds,cock fight injurycommon in south india.Other causes includes after surgical intervention of major vessels,cimino fistulaAVF created for renal dialysis. Refer page no 219 of SRBs manual of surgery 5th edition. 