Original Contribution

Ultrasound-Guided Arterial Access: Outcomes Among Patients With Peripheral Artery Disease and Critical Limb Ischemia Undergoing Peripheral Interventions

J.A. Mustapha, MD1;  Larry J. Diaz-Sandoval, MD1;  Michael R. Jaff, DO2;  George Adams, MD3;  Robert Beasley, MD4;  Sara Finton, BSN1;  Theresa McGoff, BSN1;  Larry E. Miller, PhD5;  Mohammad Ansari, MD1;  Fadi Saab, MD1

J.A. Mustapha, MD1;  Larry J. Diaz-Sandoval, MD1;  Michael R. Jaff, DO2;  George Adams, MD3;  Robert Beasley, MD4;  Sara Finton, BSN1;  Theresa McGoff, BSN1;  Larry E. Miller, PhD5;  Mohammad Ansari, MD1;  Fadi Saab, MD1

Abstract: Objective. Arterial cannulation is a vital component of endovascular interventions and often unconventional access approaches are required due to disease complexity. Historically, varying maneuvers have been utilized to obtain arterial access. Lack of consensus exists regarding the safest and most effective method. This study examined the feasibility and immediate outcomes of ultrasound-guided access in traditional and advanced access approaches. Methods. Data were analyzed from a cohort of 407 patients enrolled in the Peripheral RegIstry of Endovascular Clinical OutcoMEs (PRIME). The 407 patients underwent 649 procedures with 896 access sites utilized. Access success, immediate outcomes, complications, and length of hospital stay were analyzed. Results. Mean age was 70 years, and 67% were male. The majority of patients had critical limb ischemia (58%), 39% were Rutherford classification III. Most commonly utilized access sites were common femoral retrograde, common femoral antegrade, posterior tibial, and anterior tibial arteries (34.6%, 33.0%, 12.1%, and 12.1%, respectively). Mean number of attempts was 1.2, 1.2, 1.5, and 1.4, respectively; median time to access was 39, 45, 41, and 59 seconds, respectively; and access success rate was 99.4%, 97.3%, 90.7%, and 92.6%; respectively. Access-site combinations utilized were femoral antegrade (n = 188), femoral retrograde (n = 185), dual femoral/tibio-pedal (n = 130), dual femoral retrograde (n = 44), retrograde tibio-pedal (n = 73), and other (n = 29). Access-related complications were low overall: hematoma (1.2%), bleeding requiring transfusion/intervention (1.7%), pseudoaneurysm (1.7%), arteriovenous fistula (0.3%), aneurysm (0%), compartment syndrome (0%), and death (0%). Conclusion. Utilization of ultrasound-guided arterial access in this complex cohort was shown to be safe and effective regardless of arterial bed and approach. 

J INVASIVE CARDIOL 2016;28(6):259-264

Key words: peripheral interventions, peripheral vascular disease, critical limb ischemia, access-site management


Peripheral artery disease (PAD) is of epidemic proportions, currently affecting approximately 202 million patients worldwide. Its prevalence has increased by approximately 25% from 2000 to 2010 and its global magnitude continues to rise.1 Simultaneously, the evolution of technology has led to the use of endovascular revascularization as a primary strategy for patients with PAD and critical limb ischemia (CLI). One of the most vital components of these procedures is arterial access, and unfortunately it also represents the rate-limiting step, as it is the most commonly associated with complications.2,3 Historically, arterial access has been primarily achieved with the use of palpation, anatomic landmarks, fluoroscopic guidance, and combinations of these maneuvers. However, in current practice, lack of consensus exists regarding which method is the safest and most effective.4

Retrograde common femoral artery (CFA) access is the most frequently utilized approach for endovascular interventions.5 Careful assessment of the target site for retrograde puncture (below the inguinal ligament and above the bifurcation) is essential to avoid anatomically “high” or “low” arterial access, which accounts for up to 71% of vascular access complications.6 Fluoroscopic guidance has been recommended to improve accuracy and reduce complications.7,8 However, randomized trials failed to show superiority of these strategies to palpation of anatomic landmarks.9,10 In an attempt to further improve the technique, the use of ultrasound guidance (USG) has been attempted, as this technique had been previously shown to be safe and effective to guide central venous access.11-13 Arterial access with USG has now been studied in multiple trials comparing this approach to palpation and fluoroscopic guidance.14,15 Use of USG was found to reduce the number of access attempts, time to access, and complication rates for CFA access when compared with standard fluoroscopic guidance.14 However, there was no benefit when compared with palpation, except for patients with a weak arterial pulse and obesity.15 USG has also been recommended for less commonly accessed arterial segments, such as the superficial femoral (SFA), popliteal, and tibial arteries.16-19 Patients with advanced PAD and CLI often require unconventional approaches, including the use of antegrade CFA access and retrograde tibial accesses. There is a paucity of data regarding the safety and efficacy of USG access in these scenarios, and how these approaches compare with conventional retrograde CFA access. This article examines the feasibility and immediate outcomes of using USG in accessing a variety of complex arterial beds in patients with PAD and CLI.

Methods

Data collection. Data were obtained from patients enrolled in PRIME (Peripheral RegIstry of Endovascular Clinical OutcoMEs). This prospective clinical registry is exclusively focused on patients with PAD and CLI and is designed to explore all aspects of care from initial patient assessment to treatment and long-term follow-up (through 36 months). PRIME has been approved by the Institutional Review Board of each participating center and all enrolled patients provided written informed consent for registry participation.   

Patient population. The first 407 consecutive PRIME patients who underwent endovascular revascularization between January 2013 and April 2015 were analyzed. All peripheral vascular interventions were performed at a single United States medical center (Metro Health Hospital, Wyoming, Michigan) by four interventional cardiologists specifically trained in CLI therapy.  USG access was performed on all patients per the center’s standard practice.  

Procedural data and outcomes. Demographics, baseline symptoms, access distribution and success, immediate outcomes, and complications (to time of hospital discharge) were evaluated. Common access-site related complications were identified per the PRIME standardized data definitions: arteriovenous fistula (AVF) (abnormal connection between the artery and a vein); hematoma (localized swelling filled with blood resulting in a reduction in hemoglobin of >3.0 gm/dL); thrombosis (development of a blood clot); compartment syndrome (compression within the limb compromising the circulation and function of the tissues in that area); aneurysm (weakness in the wall of the artery that causes an abnormal widening of the vessel); pseudoaneurysm (disruption and dilation of the wall of the artery, resulting in a hematoma); and bleeding (according to the Bleeding Academic Research Consortium [BARC] classification).20 

Arterial access sites were grouped in the following categories: 

(A)    Femoral antegrade (n = 188): single antegrade CFA or proximal SFA access.

(B)    Femoral retrograde (n = 185): single retrograde CFA or proximal SFA access.

(C)    Dual femoral/tibio-pedal (n = 130): >1 access site was utilized, including retrograde contralateral CFA (“up and over”) with retrograde tibio-pedal; or ipsilateral antegrade CFA or proximal SFA with retrograde tibio-pedal access.

(D)    Dual femoral retrograde (n = 44): bilateral retrograde CFA access.

(E)    Tibio-pedal arterial minimally invasive (TAMI)retrograde revascularization (n = 73): exclusive USG tibial access with performance of the entire lower-extremity revascularization via tibial approach only.3

Ultrasound-guided access. Ultrasound-guided retrograde and/or antegrade CFA access was commonly performed by the operator using the Site-Rite Vision system (Bard Peripheral Vascular, Inc). In cases where access was considered complex (obese patients, fibrotic inguinal region, etc), an ultrasound technologist was available to provide assistance with a Philips EPiQ 5 system and an L12-5 MHz transducer (Philips Healthcare). Similarly, in patients with tibio-pedal access, an ultrasound technologist assisted with the Philips EpiQ system and the Philips 7-15 MHz variable frequency hockey stick probe.

Statistical analysis. Continuous variables are reported as mean ± standard deviation or median (minimum-maximum), depending on normality assumptions. Categorical variables are presented as number (%). Comparisons of procedural outcomes by access site were performed with the Wilcoxon-Mann-Whitney test for continuous outcomes and Fisher’s exact test for categorical outcomes. Data were analyzed using SAS 9.4 (SAS Institute, Inc). 

Results

Patient characteristics. A total of 407 patients underwent 649 peripheral arterial interventions between January 2013 and April 2015. As described in Table 1, 67% were men, average age was 70 years, and the majority were overweight (mean body mass index, 29 kg/m2). Prior to their index intervention, 39% of patients were Rutherford classification (RC) III and 58% had CLI (RC >IV). Claudication was the most common presenting symptom (80%), followed by ischemic rest pain (38%), peripheral neuropathy (24%), osteomyelitis (6%), and cellulitis (6%). 

Access sites. Throughout the 649 procedures, a total of 896 access sites were utilized. The most common arterial access segment was the common femoral artery for either retrograde (34.6%) or antegrade approach (33%), followed by the posterior tibial (12.1%), anterior tibial (12.1%), antegrade SFA (2.8%), and dorsalis pedis (1.6%). Retrograde tibial access was obtained in the distal portion of the arteries below the gastrocnemius muscle head in the calf. Antegrade SFA access was obtained at no further than 1 cm from the origin of the artery. Other arterial locations (brachial, radial, retrograde SFA, peroneal) represented less than 4% of access sites (Table 2).

As reported in Table 3, the success rates for USG retrograde and antegrade CFA access exceeded 97% (99.4% and 97.3%, respectively) and retrograde posterior and anterior tibial access success exceeded 90% (90.7% and 92.6%, respectively). The median time to USG arterial access in the most commonly utilized anatomic location and approach (retrograde CFA) was 39 seconds. Time to obtain antegrade CFA, posterior tibial, and anterior tibial access was only seconds longer (45, 41, and 59 seconds, respectively). The average number of attempts was 1.2 for both retrograde and antegrade femoral access, whereas it was 1.4 and 1.5 for anterior and posterior tibial access, respectively (Figure 1).

There was no statistically significant difference between access sites when comparing number of attempts, time to access, and access success for retrograde vs antegrade CFA. However, when contrasting tibial (posterior and anterior tibial combined) with retrograde CFA access, the findings were statistically significant in favor of retrograde CFA access (number of attempts, P<.001; time to access, P<.01; access success, P<.001).   

Although less commonly utilized, antegrade SFA had the shortest median access time (20 seconds). As reflected by the highest number of attempts and lowest success rate, retrograde peroneal artery access was the most difficult. Sonographic visualization of the peroneal artery is challenging due to the artery’s depth. In CLI patients, this challenge is amplified by the typically diffuse medial and intimal calcification, which induces a “drop out” US artifact. 

Various closure techniques were utilized depending upon access site. For common femoral retrograde, manual compression was used in 61% of cases and closure devices in 44% of cases. Rarely, a combination of these methods was required to ensure hemostasis was achieved. Comparatively, closure devices were more commonly utilized than manual compression for common femoral antegrade access (67% and 51%, respectively), with dual techniques required more frequently for the antegrade approach. The Boa tibial compression device (Lakeshore Medical Innovations) and vascular band radial compression device (Vascular Solutions, Inc) were primarily utilized for tibial access-site hemostasis. For posterior tibial sites, the radial band was used in 21% of cases and Boa device was used in 55% of cases. Similarly, the radial band was utilized 28% of the time and Boa device 43% of the time for anterior tibial access closure. The Boa compression device was also applied 57% of the time for closure of peroneal access sites.   

Access-site combinations and outcomes. The access-site combinations were grouped into the following main procedural categories: single femoral antegrade (n = 188); single femoral retrograde (n = 185); dual femoral/tibio-pedal (n = 130); dual femoral retrograde (n = 44); TAMI (n = 73); and other (n = 29) (Table 4). For single and dual femoral retrograde procedures, USG arterial access was primarily performed by the physician alone. An ultrasound technologist was utilized 35% of the time for interventions with single femoral antegrade arterial access. Alternatively, due to the complexity of the cases, an ultrasound technologist was present in 99% of dual femoral/tibio-pedal and TAMI cases to assist with arterial access.     

Overall, regardless of arterial conduit utilized, access-related complication rates were low (arteriovenous fistula, 0.3%; hematoma, 1.2%; pseudoaneurysm, 1.7%; bleeding requiring intervention, 1.7%). No patients experienced access-related thrombosis, aneurysm, compartment syndrome, or death. When comparing retrograde vs antegrade femoral access, no significant difference was observed in complication rates, fluoroscopy time (25 minutes vs 22 minutes, respectively), procedure time (81 minutes vs 84 minutes, respectively), or hospital stay (1.3 days vs 1.5 days, respectively). Antegrade CFA did result in significantly less contrast use (196 cc vs 163 cc; P<.001).  

TAMI represented 11.2% of access types and had the shortest hospital stay (mean stay, 0.9 days), 1 access-related pseudoaneurysm, no arteriovenous fistula, no hematoma, no access-site thrombus formation, no compartment syndrome, and no bleeding complications. Comparing patients who underwent TAMI vs those who had the traditional single retrograde femoral access, there was no significant difference in procedure time (81-83 minutes), but there was significantly less contrast use (57 cc vs 196 cc, respectively; P<.001), less fluoroscopy time (17 minutes vs 25 minutes, respectively; P<.001), and shorter hospital stay (0.9 days vs 1.3 days, respectively; P<.001).

Discussion

This is the first modern large-scale study to analyze the safety, efficacy, and outcomes of various arterial access approaches performed under USG to treat patients with PAD and CLI. This study confirms our previous findings supporting the use of US to obtain CFA and tibio-pedal access among patients with advanced PAD and CLI,2,3 and further confirms the utility of this imaging modality as previously reported in the FAUST trial.14 Seto et al investigated the use of US vs fluoroscopic guidance to obtain retrograde CFA access among patients undergoing cardiac catheterization. Their findings revealed that USG access improved the first-pass success rate, while decreasing number of attempts, risk of venipuncture, median time to access (136 seconds), and vascular complications. Our analysis supported these findings while revealing a superior median access time of 39 seconds when using the retrograde CFA approach. 

Dudeck et al15 compared US vs palpation-guided retrograde CFA access, and concluded that USG was only advantageous among patients who were obese or who had a weak arterial pulse, reporting a decreased number of attempts (1.8) and time to access (190 seconds), both of which compare unfavorably with our findings (1.2 attempts and 39 seconds). Based on our analysis, the claim of the limited advantages of US is not valid, since favorable outcomes were noted regardless of body habitus or vessel calcification.   

Gutzeit et al16 previously reported on the use of US to obtain antegrade SFA access, concluding that it was “feasible and fast,” despite reporting a 10.2% rate of pseudoaneurysm formation and a median access time of 210 seconds. Although the numbers were limited (n = 25), our findings were superior because antegrade SFA access resulted in no pseudoaneurysms and the median time to access was 20 seconds (the fastest access type). A potential explanation for the short time to obtain USG antegrade SFA access is based on the fact that less time is spent trying to guarantee a puncture that will not be “too high” (above the inguinal ligament) and therefore increase the risk of retroperitoneal hemorrhage. Moreover, the angle of the needle relative to the skin can be kept at the usual 45 to 60°. When accessing the CFA, the needle angle is shallower to avoid puncture into the profunda femoris artery (which is difficult to do in patients who are morbidly obese, as the pannus forces the operator to use a steeper puncture angle). 

Our analysis suggests that utilization of USG arterial access for complex peripheral vascular interventions is safe and feasible, with success and complication rates that are comparable to the conventional and widely utilized retrograde common femoral arterial access method. It is relevant to note that among patients undergoing USG antegrade CFA access, the median time to access was only 6 seconds longer than the time required to obtain retrograde CFA access and, correspondingly, there was no statistical difference in mean number of attempts or access success. Moreover, when comparing procedures where single antegrade vs retrograde femoral access was utilized, no significant difference was observed in complication rates, fluoroscopy time, procedure time, or hospital length of stay. Interestingly, the only statistical difference noted was in favor of antegrade femoral artery access with less contrast use (196 cc vs 163 cc; P<.001). These findings suggest that antegrade CFA access has results equivocal to retrograde access, which is the more commonly employed method in the United States. 

Among patients undergoing tibial artery access, statistically significant differences were noted in access attempts, time, and success when compared with conventional retrograde CFA access. Despite these differences, the results were comparable regardless of the fact that these vessels were smaller (access obtained in the distal segments), typically calcified, and had a low perfusion pressure (due to the presence of proximal occlusions), which makes them likely to collapse while being accessed. In the TAMI group, only one complication was noted (pseudoaneurysm, 1.4%), comparing favorably with previous studies on the use of retrograde tibio-pedal access, which have reported complications rates of 9.1% with US guidance21 and 9.8% without22 US guidance. In contrasting patients undergoing TAMI vs those undergoing retrograde femoral access, there was no significant difference in complication rates or procedural time, but there was significantly less contrast use (57 ml vs 196 ml, respectively; P<.001), fluoroscopy time (17 minutes vs 25 minutes, respectively; P<.001), and shorter hospital stay (0.9 days vs 1.3 days, respectively; P<.001). It is worth noting that these results were achieved despite the fact that TAMI patients had more complex anatomy and comorbidities, which typically would be associated with increased procedure times, contrast use, and length of stay, as well as lower success rates. This observation could be used to hypothesize that the use of minimally invasive techniques with USG access could result in higher success rates and lower complication rates, leading to shorter hospital stays, which in turn could translate into cost savings. 

Study limitations. Overall, this is a clinical registry with the inherent limitations of such a report. The patient population examined was from a single center with experienced operators and ultrasound technologists specifically trained in CLI therapy, and USG access was utilized for all patients as per standard practice. As a result, outcomes may have been influenced by the operator’s level of comfort and experience with USG access. PRIME currently includes other centers that do not routinely use US in obtaining access. A comparison of the outcomes of the various approaches would be beneficial once the number of patients enrolled allows such analysis. In addition, certain arterial conduits had small cohorts, limiting the overall significance of the findings. Larger scale, multicenter, randomized studies of less commonly utilized access sites may be warranted to support the generalizability of these findings.      

Conclusion

Based on this analysis of the largest contemporary cohort of patients with PAD and CLI studied to evaluate the role of US, the use of USG access was shown to be safe and effective regardless of arterial bed and approach (antegrade or retrograde). The use of US should be considered as one of several initiatives directed at quality improvement. Once mastered, it may contribute to lower complication rates, reduced radiation exposure and use of contrast, and shortened length of hospital stay. Multicenter studies with prespecified endpoints addressing these hypotheses are needed in order to confirm the potential clinical and economic impact of this strategy. In this complex patient population where advanced access approaches are required, use of US is instrumental in decreasing the access-related complication rate. 

References

1.    Fowkes FG, Rudan D, Rudan I, et al. Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis. Lancet. 2013;382:1329-1340.

2.    Mustapha JA, Saab F, Diaz L, et al. Utility and feasibility of ultrasound-guided access in patients with critical limb ischemia. Catheter Cardiovasc Interv. 2013;81:1204-1211.

3.    Mustapha JA, Saab F, McGoff T, et al. Tibio-pedal arterial minimally invasive retrograde revascularization in patients with advanced peripheral vascular disease: the TAMI technique, original case series. Catheter Cardiovasc Interv. 2014;83:987-994.

4.    Sobolev M, Slovut DP, Chang AL, Shiloh AL, Eisen LA. Ultrasound-guided catheterization of the femoral artery: a systematic review and meta-analysis of randomized controlled trials. J Invasive Cardiol. 2015;27:318-323.

5.    Narins CR. Access strategies for peripheral arterial intervention. Cardiol J. 2009;16:88-97.

6.    Sherev DA, Shaw RE, Brent BN. Angiographic predictors of femoral access site complications: implication for planned percutaneous coronary intervention. Catheter Cardiovasc Interv. 2005;65:196-202.

7.    Dotter CT, Rosch J, Robinson M. Fluoroscopic guidance in femoral artery puncture. Radiology. 1978;127:266-267.

8.    Bersin, RM. Avoiding access site and closure complications. Endovascular Today. January 2015:2.

9.    Abu-Fadel MS, Sparling JM, Zacharias SJ, et al. Fluoroscopy vs traditional guided femoral arterial access and the use of closure devices: a randomized controlled trial. Catheter Cardiovasc Interv. 2009;74:533-539.

10.    Huggins CE, Gillespie MJ, Tan WA, et al. A prospective randomized clinical trial of the use of fluoroscopy in obtaining femoral arterial access. J Invasive Cardiol. 2009;21:105-109.

11.    Hind D, Calvert N, McWilliams R, et al. Ultrasonic locating devices for central venous cannulation: meta-analysis. BMJ. 2003;327:361.

12.    Milling TJ Jr, Rose J, Briggs WM, et al. Randomized, controlled clinical trial of point-of-care limited ultrasonography assistance of central venous cannulation: the Third Sonography Outcomes Assessment Program (SOAP-3) trial. Crit Care Med. 2005;33:1764-769.

13.    Randolph AG, Cook DJ, Gonzales CA, Pribble CG. Ultrasound guidance for placement of central venous catheters: a meta-analysis of the literature. Crit Care Med. 1996;24:2053-2058.

14.    Seto AH, Abu-Fadel MS, Sparling JM, et al. Real-time ultrasound guidance facilitates femoral arterial access and reduces vascular complications: FAUST (Femoral Arterial Access With Ultrasound Trial). JACC Cardiovasc Interv. 2010;3:751-758.

15.    Dudeck O, Teichgraeber U, Podrabsky P, Haenninen EL, Soerensen R, Ricke J. A randomized trial assessing the value of ultrasound-guided puncture of the femoral artery for interventional investigations. Int J Cardiovasc Imaging. 2004;20:363-368.

16.    Gutzeit A, Schoch E, Sautter T, Jenelten R, Graf N, Binkert CA. Antegrade access to the superficial femoral artery with ultrasound guidance: feasibility and safety. J Vasc Interv Radiol. 2010;21:1495-1500.

17.    Yeh KH, Tsai YJ, Huang HL, Chou HH, Chang HJ, Ko YL. Dual vascular access for critical limb ischemia: immediate and follow-up results. Catheter Cardiovasc Interv. 2011;77:296-302.

18.    Fanelli F, Lucatelli P, Allegritti M, Corona M, Rossi P, Passariello R. Retrograde popliteal access in the supine patient for recanalization of the superficial femoral artery: initial results. J Endovasc Ther. 2011;18:503-509.

19.    Glasby MJ, Bolia A. Subintimal angioplasty of a crural vessel via an antegrade popliteal artery puncture. Eur J Vasc Endovasc Surg. 2007;34:347-349.

20.    Mehran R, Rao SV, Bhatt DL, et al. Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the Bleeding Academic Research Consortium. Circulation. 2011;123:2736-2747.

21.    Gur S, Oguzkurt L, Gurel K, Tekbas G, Onder H. US-guided retrograde tibial artery puncture for recanalization of complex infrainguinal arterial occlusions. Diagn Interv Radiol. 2013;19:134-140.

22.    Montero-Baker M, Schmidt A, Braunlich S, et al. Retrograde approach for complex popliteal and tibioperoneal occlusions. J Endovasc Ther. 2008;15:594-604.


From the 1Metro Health Hospital, Wyoming, Michigan; 2Massachusetts General Hospital, Boston, Massachusetts; 3University of North Carolina REX Healthcare, Raleigh, North Carolina; 4Mount Sinai Medical Center, Miami, Florida; and 5Miller Scientific Consulting, Inc, Asheville, North Carolina.

Funding: The authors report unrestricted research grants to Metro Health to support the PRIME registry from Bard Peripheral Vascular, Terumo Interventional Systems, Cardiovascular Systems, Access Closure, Medtronic, Boston Scientific, and Spectranetics.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Mustapha reports personal fees from Bard Peripheral Vascular, Terumo Interventional Systems, Cardiovascular Systems, Inc, Medtronic, Boston Scientific, and Spectranetics. Dr Diaz-Sandoval reports personal fees from Bard Peripheral Vascular, Terumo Corporation, and Cardiovascular Systems, Inc. Dr Jaff reports non-financial support (non-compensated advisor) from Medtronic, Boston Scientific, Abbott Vascular, and Cordis; non-financial support from the Society for Cardiovascular Angiography and Intervention (non-compensated board member); personal fees from Cardinal Health, Volcano, VIVA Physicians, a 501c3 not-for-profit education and research organization (board member), and the Association of Orthotics and Prosthetics of America (advisor); equity investment in PQ Bypass. Dr Adams reports personal fees from Bard Peripheral Vascular, Terumo Interventional Systems, Cardiovascular Systems, Inc, Medtronic, Boston Scientific, and Spectranetics. Dr Beasley reports personal fees from Bard Peripheral Vascular, Cardiovascular Systems, Inc, Medtronic, Boston Scientific, and Spectranetics. Dr Miller reports personal fees from Metro Health Hospital and Spectranetics. Dr Fadi reports personal fees from Bard Peripheral Vascular, Terumo Interventional Systems, Cardiovascular Systems, Inc, Medtronic, Boston Scientific, and Spectranetics..

Manuscript submitted March 23, 2016, provisional acceptance given March 24, 2016, final version accepted April 4, 2016.

Address for correspondence: J.A. Mustapha, MD, Metro Health Hospital, 5900 Byron Center SW, PO Box 9490, Wyoming, MI 49519. Email: jihad.mustapha@metrogr.org

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