Mechanical Enhancement of AVF Maturation

Abstract

A native arteriovenous fistula (AVF) should be systematically evaluated at 4 to 6 weeks after creation. Any clinical indications of nonmaturation should be promptly followed up and confirmed by detailed duplex ultrasonography looking for a deep vein or inadequate access flow due to stenoses. Once vein depth has been ruled out, a significant stenosis is invariably identified and should therefore be operated on or dilated. Predilation angiography should be performed preferably through the brachial artery. Arterial lesions are frequent causes of nonmaturation of forearm AVFs and should therefore be dilated. The best results are obtained when the juxta-anastomotic vein and the feeding artery are dilated with 6 and 4 mm dilation balloons, respectively. Our opinion is that there is no or only the very rare indication for ligation or embolization of collaterals. Rupture of the weak venous or arterial wall is common (15% of cases), the majority of which can be managed with prolonged balloon tamponade. Nonmaturing AVFs are ideally needled only 7 to 14 days after successful dilation to allow hematomas caused by cannulation and local anesthesia to resorb. Including initial failures, 1-year primary and secondary patency rates reported by interventional radiologists range from 34% to 39% and 68% to 79%, respectively. Results after dilation of diseased radial arteries feeding normal veins are even better, with primary patency rates ranging for 65% to 83%, and secondary patency rates of over 90%. Using an aggressive and multidisciplinary treatment strategy, nonmaturing dialysis fistulas can be identified, evaluated and salvaged with angioplasty.