High Femoral Artery Bifurcation Predicts Contralateral High Bifurcation: Implications for Complex Percutaneous Cardiovascular Procedures Requiring Large Caliber and/or Dual Access

Abstract: Recent advances in technology have led to an increase in the use of bilateral femoral artery access and the requirement for large-bore access. Optimal access is in the common femoral artery (CFA), rather than higher (in the external iliac artery) or lower (in one of the branches of the CFA). However, there is a paucity of data in the literature about the relationship between bifurcation level of one CFA and the contralateral CFA. To define the prevalence of high bifurcation of the CFA and the relationship between bifurcation level on both sides, we performed a retrospective analysis of all patients with bilateral femoral angiography. From 4880 femoral angiograms performed at UCSF cardiac catheterization laboratory between 2005-2013, a total of 273 patients had bilateral femoral angiograms. The prevalence of low/normal, high, and very-high femoral bifurcations was 70%, 26%, and 4%, respectively, with no difference between sides. A high or very-high bifurcation significantly increased the likelihood of a high bifurcation on the contralateral side (odds ratio >3.0). Multivariable logistic regression analysis revealed age, gender, self-reported race, height, weight, and body mass index were not predictive of high or very-high bifurcations on either side. In conclusion, high femoral artery bifurcations are common and increase the likelihood of a high bifurcation of the contralateral femoral artery.

J INVASIVE CARDIOL 2014;26(9):409-412

Key words: arterial access, femoral access, large-caliber device

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Recently, advances in technology have facilitated the emergence of percutaneous procedures that typically require large-caliber and/or bilateral femoral arterial access, such as transcatheter aortic valve replacement (TAVR), placement of percutaneous ventricular assist devices (such as Impella) for high-risk percutaneous coronary intervention (PCI), and PCI for chronic total occlusion (CTO). Vascular complications following femoral artery cannulation are more common when access is not in the common femoral arterial segment. Anatomical knowledge of the relationship of the femoral artery to the femoral head helps the operator avoid vascular complications while gaining access to the femoral artery. Furthermore, when bilateral femoral arterial access is required, knowledge of the relationship between right and left femoral artery bifurcation levels may help the operator predict the bifurcation level on one side based on the level of the contralateral side. However, there is a paucity of data in the literature to help guide the operators in this aspect. Ideally, puncture of the femoral artery should be performed at the level of the common femoral artery (CFA). If the puncture site is too proximal, the risk of entering the external iliac artery increases, consequently increasing the risk for retroperitoneal hemorrhage. Whereas, if the puncture site is too distal, the risk of entering into one of the 2 branches of the CFA (profunda femoris or superficial femoral artery) increases and therefore increases the risks of vascular complications like pseudoaneurysm or arteriovenous fistula.^1-6 Additionally, due to interpersonal variations in anatomy, the high variability of the CFA bifurcation level with respect to the femoral head can result in an entry point into the femoral artery that is either too low (below the bifurcation) or too high (in the external iliac artery), even though the puncture site in relation to the femoral head may be in the desired zone.⁷ This may result in an access location unsuitable for serial dilatation and insertion of a large-caliber sheath. We therefore compared the bifurcation level of the femoral artery in relationship to the femoral head on each side in patients who have had bilateral femoral angiograms. We describe the likelihood of a high bifurcation on each side and show that high bifurcations on one side are associated with an increased likelihood of a high bifurcation on the contralateral side. This information will help the operators in planning femoral arterial access and predicting the level of femoral artery bifurcation on one side based on the known level of bifurcation on the contralateral side.

Methods

Patient group. All patients undergoing femoral angiograms at UCSF cardiac catheterization laboratory from 2005 to 2013 were included. Out of this patient group, all patients who had bilateral femoral angiograms recorded (either on same or different date) were identified by searching the cardiac catheterization laboratory database. The femoral angiograms of these patients were examined for the level of femoral artery bifurcation with respect to femoral head and compared bilaterally. The study was approved by the UCSF Committee on Human Research.  

Anatomic landmarks. The femoral head was used as the radiologic landmark for adjudicating the level of the femoral artery bifurcation. The common femoral artery distally divides into the profunda femoral artery (PFA) and superficial femoral artery (SFA). Each femoral artery was assigned one of three designations. If the bifurcation level of the femoral artery was inferior to the inferior border of the femoral head, then the bifurcation level of the femoral artery was deemed a “low/normal” level of bifurcation. If the bifurcation level was at, or superior to, the inferior border of femoral head but inferior to the midpoint of the femoral head, it was deemed a “high” bifurcation of the femoral artery. If the bifurcation level was at, or superior to, the midpoint of the femoral head, the bifurcation of femoral artery was deemed a “very high” bifurcation. In the event a patient had hip replacement by prosthesis, two separate cardiologists performed the review of level of bifurcation and came to a consensus. These landmarks are schematically shown in Figure 1 and angiographically in Figure 2. Although these landmarks are different from those used in the past,⁷ for clinical purposes, they are the most useful and well utilized landmarks of the femoral head for adjudication of the femoral arterial relationship anatomically.

Angiography. Femoral angiograms were recorded in the 30-50° ipsilateral anterior oblique view with no cranial or caudal angulation. These angiograms were reviewed for determination of the level of femoral artery bifurcation in respect to the femoral head. Bilateral femoral artery angiogram comparison was recorded. Various demographic variables, which could plausibly be associated with variations in the site of bifurcation, were collected by chart and/or database review.

Statistical analysis. Data are presented as number (%) of patients unless otherwise stated. Multivariate logistic regression analysis was performed to evaluate the association between demographic and angiographic variables with the level of femoral artery bifurcation. All statistical analyses were performed used software STATA version 10.

Results

There was a total of 4880 femoral angiograms performed at UCSF cardiac catheterization laboratory between 2005- 2013. Out of these, 273 patients had bilateral femoral angiograms available for review. The baseline characteristics of these patients are listed in Table 1.

The number of patients with low/normal, high, and very high bifurcations of the right common femoral artery were 196 (72%), 68 (25%), and 9 (3%), respectively. The number of patients with low/normal, high, and very high bifurcations of the left common femoral artery were 188 (69%), 74 (27%), and 11 (4%), respectively (Table 2, Figure 3). There was no statistically significant difference in the proportion of patients with high or very high bifurcations on the left compared to the right.

The presence of a high bifurcation on either side increases the likelihood of a high bifurcation on the other side. If the right CFA bifurcates high, the odds ratio [OR] of the left CFA bifurcating high is 3.37 (95% confidence interval [CI], 1.86-6.10; P<.001). If the right CFA bifurcates very high, the OR of the left CFA bifurcating high is 3.22 (95% CI, 0.83-12.6; P=.09). If the left CFA bifurcates high, the OR of the right CFA bifurcating high is 3.95 (95% CI, 2.15-7.26; P<.001). If the left CFA bifurcates very high, the OR of the right CFA bifurcating high is 14.6 (95% CI, 3.7-58.4; P<.001). Multivariable logistic regression analysis revealed that age, gender, self-reported race, height, weight, and body mass index were not predictive of high or very high bifurcations on either side.  

Discussion

The femoral artery is still the most commonly accessed artery for performing both cardiac and peripheral percutaneous vascular procedures. Yet femoral artery vascular access complications are unacceptably high (in the range of 2%-10%).⁷ Our study has several important findings. First, over 40% of patients will have high bifurcation in either of their femoral arteries. Second, if one femoral artery has a high or very high bifurcation, the contralateral side is more likely to also have a high bifurcation. Third, the prevalence of high and very high bifurcations does not differ between the right and left, so choosing one side over the other will not reduce the risk of encountering a high bifurcation. These data will assist the operator in planning contralateral femoral artery access when faced with a high or very high femoral artery bifurcation on one side.

The rates of high femoral bifurcation appear high at first glance. However, our data are consistent with prior literature. In particular, Schnyder et al showed similar, or slightly higher, rates of high and very high arterial bifurcations (Table 3).⁷ The definition of a high CFA bifurcation can be debated. We chose a definition that was previously used in the literature and has an easy, practical applicability. Unfortunately, we found no clinical predictors of high bifurcation that would predict high CFA bifurcation before initial access is attempted. Further, there was a difference in the prevalence of high or very high bifurcation on the left and right sides. Thus, we were only able to address the question of whether one high bifurcation predicts a contralateral high bifurcation.

In recently published data, it was shown that there are approximately 189,836 TAVR candidates (95% CI, 80,281-347,372) in the European countries and 102,558 TAVR candidates (95% CI, 43,612-187,002) in North America. Annually, there are 17,712 new TAVR candidates (95% CI, 7,590-32,691) in the European countries and 9189 new TAVR candidates (95% CI, 3,898-16,682) in North America.⁸ As the prevalence of these patients requiring percutaneous procedures increases, the need for bilateral femoral arterial access will also increase. Another procedure that is increasing in frequency is PCI for CTOs. Frequently, this will require bilateral femoral artery access. With the prevalence of CTOs as high as 89% and 15% of patients with and without prior history of coronary artery bypass graft surgery,⁹ the potential growth of CTO PCI is large. CTOs are commonly found at the time of coronary angiography and account for 5%-10% of total PCIs performed in the United States.¹⁰ Our data will caution the operator in planning contralateral femoral artery access when faced with a high or very high femoral artery bifurcation on one side. In such cases, other techniques like ultrasound guidance could be used to access the femoral artery safely. One study¹¹ showed that routine real-time ultrasound guidance improved CFA cannulation only in patients with high CFA bifurcations. In such cases, an ultrasound will help visualize the femoral arterial bifurcation, which can then be co-related to the femoral head anatomically. Alternate access sites, such as the radial artery, could also be considered.

Procedures like percutaneous left ventricular support device placement or TAVR require the placement of a large-size cannula in the femoral arteries. In these procedures, the overall success is also determined by the safety of femoral arterial access. If the access site is below the bifurcation of the femoral artery, then the size of the artery limits the placement of large sheaths. Furthermore, most vascular closure devices used during these procedures are only approved for use in the common femoral artery, limiting the use of these devices when the arteriotomy is in a branch vessel.

Study limitations. Although definite anatomical markers were used to define the levels of bifurcation of the femoral artery and experienced operators were used to adjudicate the bifurcation levels, subjective error could still not be completely avoided. Also, this is a small retrospective review of angiograms, so the results need to be verified with large, prospective analyses. 

Conclusion

High bifurcation of either femoral artery is common. Bifurcation of the common femoral artery at, or superior to, the inferior border of the femoral head on angiography increases the likelihood that the contralateral femoral artery will also have a high bifurcation. These data may potentially help procedural planning when bilateral femoral arterial access is required.

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From the ¹Department of Medicine, Division of Cardiology, University of California, San Francisco; and ²Department of Cardiology, John Hunter Hospital, University of Newcastle, Australia.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted January 17, 2014, provisional acceptance given February 14, 2014, final version accepted March 24, 2014.

Address for correspondence: Andrew Boyle, MBBS, PhD, FRACP, FAHA, FACC, FSCAI, Professor of Cardiovascular Medicine, John Hunter Hospital, Cardiology Department, Locked Bag No 1, HRMC, Newcastle, NSW 2310, Australia. Email: andrewboyle500@gmail.com