Journal for Vascular Ultrasound

—To assess the impact of a structured duplex ultrasound hemodialysis access surveillance program on the frequency of diagnostic fistulograms and endovascular interventions.

—A structured ultrasound hemodialysis access surveillance program was implemented at our institution on March 1, 2010. The access ultrasound comprised the measurement of vessel diameter, velocity, and flow in the feeding artery, anastomosis, and at specific points along the outflow vein (2.5, 5.0, 7.5, and 10 cm beyond anastomosis) along with a waveform pattern in the ipsilateral axillary and internal jugular vein. In this retrospective multicenter study, we compared the frequency of diagnostic contrast fistulograms and endovascular interventions (angioplasty) performed from March 2010 to February 2011 (12 months) by using the implemented ultrasound access surveillance program (postsurveillance) to the preceding 12 month period (March 2009 to February 2010) where no ultrasound access surveillance program was used (pre-surveillance).

—Within our hemodialysis program, there was an average of 119 active fistulae during the presurveillance period versus 141 in the postsurveillance period. There were no significant demographic differences in our study populations across the two time frames (p > 0.05). In the presurveillance period, 59 diagnostic contrast fistulograms were performed, whereas 47 diagnostic contrast fistulograms were performed during the post surveillance period. Using a two-sample test for equality of proportions, we found there was a significant decrease in the proportion of diagnostic contrast fistulograms after implementation of an access ultrasound surveillance program (p = 0.0114). Similarly, 81 endovascular interventions were performed during the presurveillance period, whereas a significantly decreased number of endovascular interventions (n = 50) were performed postsurveillance (p < 0.0001).

—There was a significant decrease in the number of invasive diagnostic contrast fistulograms and endovascular interventions upon implementation of an ultrasound access surveillance program. Such a structured surveillance program has the potential to provide significant reduction in patient discomfort and to minimize unnecessary invasive endovascular procedures.

—High resistive internal carotid artery (ICA) waveforms (high peak systolic velocity >250 cm/sec with low end-diastolic velocity (EDV) <125 cm/sec, having an external carotid artery waveform appearance) are uncommon and present a diagnostic challenge for intervention. Most ICA stenotic classifications rely on a greater EDV to delineate a critical stenosis of 80–99%.

—Review of a multiple-laboratory, single-center, Intersocietal Accreditation Commission-accredited, noninvasive vascular laboratory database for ICA carotid examinations performed from January 1, 2008 to November 1, 2012, with a positive stenotic range >60%. Medical records, archived ultrasound images, and correlative imaging studies were reviewed.

—A total of 843 carotid duplex studies (1,686 arteries) positive for >60% stenoses of at least one side were reviewed. There were 102 duplex studies with high resistive ICA waveforms that were identified. Of these, 35 duplex studies had 40 correlative results, and 67 duplex studies did not have any correlative results. Of the 35 correlated duplex studies, median age was 78 years (range, 53–86 years). Gender distribution was 57% male. The median age of the male subjects was 77 years with a range of 63–82 years and the median age of female subjects was 73 years old with a range of 53–86 years. Seven of the 35 patients presented with symptoms of visual disturbance, transient ischemic attack, or syncope (21% symptomatic). Side distribution was 12 males and 8 females had right-side involvement, and 7 males and 7 females had left-side involvement. There was one female patient who had bilateral involvement. This provides us with 36 duplex ultrasound studies to correlate. Mean PSV was 369 cm/sec (range, 187–492 cm/sec). Mean EDV was 89 cm/sec (range 18–130 cm/sec). Average ICA/common carotid artery ratio was 6.2 (range, 3.2–12.5). Correlative computed tomography angiography was available for 12 of the studies, angiography for 10 of the studies, and surgical findings for 18 of the 35 studies.

—Assessing all Doppler parameter used to categorize an ICA stenotic range may be beneficial in determining the need for patient intervention. Sonographer impression of audible clues and cardiac history is helpful to the interpreting physician reviewing 2D images and waveforms.

—Current imaging techniques are limited in their ability to quantify thrombus burden, progression, or resolution in patients with acute deep-vein thrombosis (DVT). These assessments are critical measures of therapeutic success when thrombolytic or thrombectomy treatment protocols are used for DVT. We have developed a novel freehand three-dimensional (3D) ultrasound method to measure thrombus volume. In this study, we evaluated the reliability of this new technology.

—We studied consecutive hospital inpatients with a first episode of acute DVT. Treatment decisions were not influenced by the study protocol. A combination of routine imaging in grayscale, color-flow, and power-Doppler modes along-with freehand 3D volumetric imaging with a linear transducer attached to an external tracking sensor was performed using a personal computer–based ultrasound scanner. Image-processing software loaded on the personal computer was used to process and reconstruct the serial cross-sectional images of the affected veins and outlined thrombus into a composite 3D image. Imaging and processing was performed twice by one sonographer, and repeated once by another sonographer.

—The mean age of patients was 56.7 ± 15 years; 40% were women. A total of 70% of DVTs were in the lower extremity and 60% received anticoagulation. Thrombus volume was reliably determined by our protocol. The mean inter- and intraobserver differences in measurements were −0.09 ± 0.59 cm³ and 0.23 ± 0.43 cm³ (mean ± SD), which were well within 2 SD (Bland Altman statistics) of the mean volumes. Measurements of the second sonographer correlated well with those of the first (regression slope = 0.95 ± 0.07, p = 0.001) and those of the first observation correlated with the second observation performed by the same sonographer (regression slope = 0.91 ± 0.03, p = 0.001). Interrater agreement was good between the two sonographers (kappa = 0.71) and between two measurements by the same sonographer (kappa = 0.82).

—We have developed a novel freehand 3D-ultrasound imaging technique and protocol that reliably measures venous thrombus volume. There is good agreement in measurements between two observers and repeated measurements by one observer. The technique can be readily adapted for routine clinical practice. This protocol will be of increasing value as the appreciation for the deleterious effects of residual thrombus after DVT increases; and the use of aggressive thrombus removal treatments for acute DVT increases.

—To describe a case of axillary artery embolus detected by emergency physician- performed bedside ultrasound.

—A patient presented with a possible stroke but was diagnosed correctly with acute axillary artery embolus. The axillary artery embolus was detected by the emergency physician by the use of bedside ultrasound.

—An acute axillary artery embolus was detected rapidly by emergency physician-performed bedside ultrasound. This led to rapid definitive vascular surgical care.

—Rapid bedside emergency ultrasound of the upper extremity arterial system can accurately detect life- and limb-threatening pathology and expedite, as this case demonstrates, definitive limb-saving surgical care.

—Although popliteal vein aneurysms are the most common of all venous aneurysms, they are exceedingly rare. In fact, there have only been approximately 150 reported cases to present. We present a case of a popliteal vein aneurysm found in a patient with right lower-extremity symptoms.

—A 51-year-old woman presented with right lower-extremity pain and swelling and was evaluated for deep venous thrombosis via venous duplex ultrasound.

—Venous duplex ultrasound of the bilateral lower extremities was performed upon presentation to an outside hospital and again after referral to our vascular surgery service.

—Original duplex as well as repeat after referral to our vascular surgery service were found to be negative for deep venous thrombosis but revealed a 2.7 by 2.1-cm fusiform popliteal vein aneurysm on the right (symptomatic) side.

—Although many venous aneurysms are clinically insignificant, popliteal vein aneurysms present a poorly characterized risk for pulmonary embolism (some estimates are as high as 70–80%), which can be potentially fatal. Therefore, surgical repair is generally warranted, especially in cases in which the diameter is greater than 2.0–2.5 cm, as in this case. Our patient, however, declined surgical intervention despite this information. Thus, in addition to presenting our case as well as mentioning standard surgical techniques, we will briefly comment herein on the limited nonsurgical treatment options for popliteal venous aneurysms found in the literature.