Clinical suspicion for IPA should follow any percutaneous intervention resulting in a swollen groin or soft tissue hematoma. Hard signs of persistent bleeding include pulsatile bleeding at the access site or expanding hematoma. The presence of a femoral bruit or thrill may also indicate an IPA; however, their absence does not exclude it. Most commonly, IPA is associated with a painful access site with associated hematoma and ecchymosis of varying size. Unfortunately, physical examination alone is notoriously inaccurate in identifying IPA. Angiography was historically the gold standard for diagnosis of IPA, until Mitchell et al. reported successful diagnosis by color duplex ultrasound in 1987 [5]. Since that time, arterial duplex evaluation has emerged as the gold standard and initial modality for diagnosing an IPA, with nearly 100% diagnostic accuracy. We typically use a 5- to 7-mHz probe in longitudinal orientation with vessel sampling and velocity measurements of the femoral artery and its branches. Changing orientation to the transverse plane allows diagnostic confirmation, sac size measurement, and evaluation for presence of thrombus within the pseudoaneurysm (Fig. 27.1). Duplex evaluation should include views of the inflow, distal external iliac, common femoral, deep femoral, and proximal superficial femoral arteries. Visualization of the common femoral vein is particularly important to exclude the presence of an associated arteriovenous fistula. IPA anatomic features to be reported should include maximum sac size, diameter of sac with flow, sac shape, neck diameter, and length. The sac size of the pseudoaneurysm should be measured in maximum squared centimeters, which is the most important parameter for determining treatment options. However, the length and width of the neck are also important to record. Larger neck widths often directly correlate with larger arterial defects that are generally more refractory to treatment with minimally invasive techniques. Multilobed IPA(s) likewise may be more difficult to treat. In our previous series, up to 20% of IPA(s) were multilobed. Typical characteristics noted on duplex imaging include a swirling of color flow within a hematoma outside of the underlying artery, color flow signal in a tract leading to a sac, and classic to-and-fro color flow in the pseudoaneurysm sac (Fig. 27.2).

Until the early 1990s, femoral cutdown with suture repair of the femoral defect was the standard treatment for those not managed conservatively. In 1991, Fellmeth et al. described a nonoperative technique for thromboses of IPAs and arteriovenous fistulas. With an overall success rate of 93%, this noninvasive alternative to surgical repair was welcomed [8]. Following this initial report, the use of ultrasound-guided compression (UGC) became the first-line treatment for those who were hemodynamically stable and without associated infection or skin necrosis. This technique includes a linear or curvilinear probe (5 or 7 MHz) to compress the IPA and arrest IPA blood flow. Real time, duplex, and color Doppler are used to identify the neck of the pseudoaneurysm. Manual compression is subsequently applied by the technologist to the neck of the aneurysm with the transducer, permitting flow through the native artery while preventing flow into the pseudoaneurysm sac. Continuous evaluation during compression is essential to arrest flow in the pseudoaneurysm sac and ensure flow in the native artery. Pressure is maintained for 10-min intervals, at the end of which pressure is slowly released and flow into the pseudoaneurysm reassessed. This is continued until thrombosis, operator fatigue, or patient discomfort occurs. Success with this treatment modality generally ranges from 60% to 90% [9–11]. Despite this acceptable success rate, compression times in excess of 1 h can be required and multiple compression sessions may be required to induce thrombosis of >10% of IPA(s). Factors associated with failed compression have been evaluated in previous publications. Ongoing anticoagulation has been shown in several series to significantly reduce successful compression, as reported by Coley et al. [10] and Eisenburg et al. [12]. They describe failure rates of 38% and 70%, respectively, in anticoagulated patients, whereas failure rates in the groups without concurrent anticoagulation were 5% and 26%. In addition, 75% of those in Coley’s series ultimately had their anticoagulation stopped and underwent repeat UGC with successful thrombosis. Also a series by Dean et al. reported a 73% success rate of UGC in 77 patients with uninterrupted anticoagulation, with seven patients requiring multiple sessions (12.5%) to obtain sustained thrombosis. Maximum aneurysm diameter appeared to be the best predictor of successful treatment with UGC [13]. With increasing pseudoaneurysm sac size, the technical success of ultrasound-guided compression decreases. Coley et al. achieved a 100% success rate in pseudoaneurysms <2 cm but only a 67% success with UGC in those 4–6 cm. Although it seems intuitive that a shorter tract length and larger neck diameter would have less success with compression, this has not been widely reported. Limited data is available on neck length or diameter on success of ultrasound-guided compression. A small series reported a short tract length (<5 mm) had unfavorable compression outcomes; however, this study was limited by a small sample size of only 12 patients [14].

Complications following UGC include arterial or venous thrombosis. Also, several cases of pseudoaneurysm rupture have also been reported. Successful thrombosis occurs at an acceptable rate, but there are several limitations to this technique. These include the requirement at some facilities for a physician to be present during the entire procedure, potential long procedures times, local patient discomfort that often requires conscious sedation, and newer techniques with higher success rates now being available.