Interim results of 4F and 6F access site complications advocate for an ambulatory approach for treatment of PAD

Marianne Brodmann presenting at LINC in 2017

The results of a study seeking to compare access site complications in 4F and 6F devices for treatment of peripheral arterial disease (PAD) report that ambulatory treatment presents a valid option for endovascular procedures in lower limb arteries, with the additional benefit of both the 4F and 6F devices negating the need for a vascular closure device.

These interim data were presented by Marianne Brodmann from Medizinische Universtität Graz, Graz, Austria, at the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) annual meeting (22–25 September, Lisbon, Portugal).

According to Brodmann, ambulatory treatment is becoming more frequent, with peripheral vascular interventions as well as coronary interventions—now carried out using radial access—becoming more commonplace in outpatient settings. Brodmann acknowledged this trend, suggesting that ambulatory treatment is growing not only for vascular interventions, but in every medical field.

However, she reported that the main concern related to ambulatory treatment is access site complications. Previous data from the 4 EVER trial that used a 4F puncture system reported a puncture site complication rate of 3.3%, indicating that it is possible to achieve such low rates.

Therefore, Brodmann and colleagues sought to compare the rate of access site complications in 4F versus 6F femoral access devices for endovascular treatment of lower-extremity PAD in an ambulatory setting. The investigators conducted a multicentre, prospective, controlled trial aimed at demonstrating non-inferiority of the primary endpoint (access site complications) with a non-inferiority margin of 2%; assuming an access site complication rate of 5% in 6F and 3% in 4F.

In total, 792 patients suffering from infrainguinal PAD are to be treated; with 388 patients so far assigned to either the 4F or 6F device, per physician’s discretion. The primary endpoint includes both peri- and post-procedural access site complications (including homeostasis strategy failure), with post-procedural outcomes defined as within 30-days post-intervention. Secondary endpoints include procedural success, sub-evaluation of access site complications according to severity, ambulatory failures, time to haemostasis, and time to discharge. The endpoints reported so far have been adjudicated by a clinical event committee.

Regarding the preliminary results, a total of 576 lesions have so far been treated, covering all kinds of lesions, including: common femoral, superficial femoral artery, popliteal artery and below-the-knee lesions, using an ambulatory approach. More below-the-knee procedures were carried out using the 4F system (19.5%) compared to the 6F (12.1%), while more SFA procedures were carried out using the 6F system (54.1% vs. 45.8% for 4F).

The main difference between the cohorts was that a vascular closure device was used in 6.6% of the 4F patients, but in over 80% of the 6F patients. Further differences include that a compression device was used in 48% of the 4F patients compared to the 29.9% of 6F patients, while both manual compression time and time to haemostasis was doubled in the 4F patients when compared with the 6F (from 4.8±8.437 to 10.92±9.718mins, and 7.17±10.301 to 13.49±13.66mins, respectively). Brodmann attributed this finding to the predominant use of vascular closer devices in the 6F patient cohort. Additionally, the diameter of common femoral artery at the puncture site was slightly lower in the 4F cohort (6.51±1.81 vs. 6.9±1.169mm2 for the 6F cohort).

Time to patient discharge (8.15±11.006 hours for 4F and 8.57±14.147 hours for 6F) and procedural success (95.1% for 4F and 95.5% for 6F) was similar in both cohorts. Furthermore, discharge that occurred the same day as the procedure occurred at a similar rate for both cohorts.

Although Brodmann acknowledged that further evaluation of the full cohort is needed to draw more concrete conclusions, she concluded that within the range of the current study, ambulatory treatment is a valid option for endovascular procedures in lower limb arteries. Elaborating, she maintained that 4F compatible products show similar results when compared to the already well-established 6F devices—and so remain a valid alterative based on patient need and physician reference—with the additional benefit in that they negate the need of a vascular closure device.


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