Recent Vascular Guidelines with a Focus on Imaging

Two important guidelines published in late 2011 impact the use of noninvasive vascular imaging. I have summarized the recommendations with an emphasis on the imaging components.

Ultrasound Guided Vascular Access Guidelines. Guidelines for Performing Ultrasound Guided Vascular Cannulation: Recommendations of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists was published in December 2011 in JASE. The Agency for Healthcare Research and Quality recommended in 2001 that ultrasound be used in the placement of all central venous catheters. The guideline includes a comprehensive review of the methodology for ultrasound guided line insertion and discusses the supporting evidence. Specific recommendations include: (1) Real-time ultrasound be used during internal jugular vein cannulation whenever possible (category A supportive, level 1 evidence multiple randomized trials); (2) High-risk patients may benefit from ultrasound screening of the subclavian vein before attempted cannulation (Category A, level 3 evidence single randomized trial); (3) Real-time ultrasound be used only for examining the femoral vein to identify vessel overlap and patency when feasible (category C equivocal); (4) Real-time ultrasound imaging should be used to confirm vessel cannulation by imaging the guide wire in the target vessel. The council does not recommend the routine use of real-time ultrasound imaging for arterial access or peripheral venous catheter placement. For training, the council recommends formalized education with lectures, demonstrations and supervision. Prior to independent practice, the council recommends a minimum of 10 supervised ultrasound-guided vascular catheter placements that can include the use of simulators. The publication also includes a video demonstration that can be downloaded from the Website. The full text, including many useful diagrams, is available at asecho.org/guidelines .

2011 ACCF/AHA Focused Update of the Guideline for the Management of Patients with Peripheral Artery Disease was released in September 2011. For vascular testing, the most important change from the 2005 guideline regards the expanded use of ankle-brachial index (ABI) measurements. The updated recommendation is to perform a resting ABI on individuals suspected PAD including those with exertional leg symptoms, non-healing wounds, age 65 or older (changed from 70), or those age 50 or older with a history of smoking or diabetes. The level of evidence is now B (from C) based on multiple recent large studies showing improved risk prediction for cardiovascular events with the inclusion of ABI results. The new guideline also created recommendations for uniform reporting of ABI results: (1) non-compressible ABI >1.4, (2) normal 1.00 to 1.40, (3) borderline 0.91-0.99 and (4) abnormal (diagnostic for PAD) ≤0.90.