Endovascular-first treatment strategies are increasingly becoming the norm for revascularization in patients with peripheral arterial disease (PAD) and critical limb ischemia (CLI). For example, the LIBERTY study results indicated that peripheral endovascular intervention is a viable treatment option for Rutherford class (RC) 2/3, RC 4/5, and RC 6 patients, as evidenced by the high freedom from major amputation, as well as the improvement in quality of life and the RC at 12 months.1 In addition, the important CRITISCH (Registry of First-line Treatments in Patients With Critical Limb Ischemia) study indicated no differences in amputation-free survival rate for those patients undergoing endovascular therapy with those undergoing open surgical approaches as a first-line treatment.2 The less invasive endovascular approach offers several advantages over open surgery, including lower morbidity and mortality, faster functional recovery, and less bleeding. Minimizing bleeding is a critical factor in maintaining the success of this approach.
Major bleeding during endovascular revascularization is an independent predictive factor of adverse outcomes, including major adverse cardiac events (MACE) and mortality, regardless of access site. Interestingly, sheath size is directly correlated with such outcomes, as it has been shown to be an independent predictor of bleeding in these procedures. The larger the sheath size, the greater the risk of bleeding and need for blood transfusions. Considering this, physicians should be aware of approaches and devices that could mitigate bleeding complications in their patients. Usage of smaller sheaths, such as the 4 French size, could significantly improve outcomes of revascularization procedures.
J.A. Mustapha, MD: Before we get started, where do you perform your PAD procedures?
William Julien, MD: Essentially, all are performed in my office interventional suite, which we opened in March of 2005.
Dr. Mustapha: What is your protocol in deciding sheath size and access location?
Dr. Julien: All arterial punctures are performed with ultrasound guidance and 4 French (Fr) micropuncture. We typically have a good idea of the anatomy beforehand with a detailed duplex ultrasound from our vascular lab and sometimes computed tomography angiography (CTA). I particularly like CTAs in patients I suspect of iliac disease, such as proximal claudication, reduced common femoral artery pulses, or reduced waveforms on ultrasound. If iliac disease is suspected, we normally would start in the contralateral groin, and that would allow us to treat the iliac disease and potentially infrainguinal on the opposite leg. More recently, we have adopted radial artery access for treatment of iliac disease and proximal leg disease in some cases. For an infrainguinal case, however, we typically would perform an antegrade common femoral puncture. About 80% of our PAD cases are approached with antegrade common femoral artery (CFA) access or retrograde pedal access.
For all cases, we start with a 4 Fr sheath, and then if needed, we upsize to a larger sheath size to accommodate larger devices, such as placing an iliac stent. In the past year, 80% of our cases have been 4 Fr and 20% have been 6 Fr. If I am remotely concerned about a 4 Fr access site issue, I image first with a 3 Fr inner dilator before committing to the access. Then we can decide whether to continue with the 4 Fr sheath size, use an alternative access site, such as pedal, or upsize the sheath.
Dr. Mustapha: What prompted you to incorporate 4 Fr access for your endovascular procedures?
Dr. Julien: The general notion that larger sheath sizes are associated with increased bleeding and the need for closure devices prompted me to try 4 Fr access. A larger sheath can be occlusive and difficult to move through the vessel. Six French sheaths will often obstruct the flow. On the contrary, a 4 Fr sheath rarely ever obstructs the flow, incurs fewer bleeding issues, and decreases the need for a closure device at the end of the case. The 4-EVER trial (4-F endovascular treatment approach to infrainguinal disease) demonstrated that the 12-month patency rate was similar between 4 Fr and 6 Fr access in stenting femoropopliteal occlusive lesions without a closure device.3
Dr. Mustapha: What are the advantages of 4 Fr access?
Dr. Julien: Patient recovery time is much shorter. The faster ambulation time, decreased bleeding risk, and our ability to end the case with manual compression instead of a closure device are advantages for both the patient and the facility. In addition to maintaining efficacy, the 4-EVER trial showed that the usage of 4 Fr devices resulted in fewer access site complications and shorter manual compression times than usage of 6 Fr devices.3
Dr. Mustapha: What are some of the challenges of incorporating 4 Fr access for endovascular procedures?
Dr. Julien: We can’t place standard iliac stents or traditional, nitinol self-expanding stents, or interwoven nitinol stents. However, we are now able to place select nitinol stents since Biotronik AG’s 4 Fr-compatible nitinol peripheral stents have been approved by the FDA.4 It would be nice to see a broader range of choices from other manufacturers.
We are also limited in that we cannot use specialty balloons such as the Cutting (Boston Scientific), Chocolate (Medtronic), and drug-coated balloons. Use of a 4 Fr access may limit the balloon size that can be used, particularly for larger balloons. The operator may encounter a lack of sufficient support from the sheath or find it necessary to upsize later in the procedure, especially if the need to place a 6 Fr-compatible stent arises.
Dr. Mustapha: What specialty devices do you use for your 4 Fr access procedures?
Dr. Julien: For atherectomy devices, we use the Diamondback 360 orbital atherectomy system (Cardiovascular Systems, Inc. [CSI]), up to 1.25 mm solid and micro crown, or laser (Philips), up to 1.4 mm over the wire. Technically, the 1.4 mm catheter is labeled as 5 Fr-compatible, but we use it in a 4 Fr sheath. So, between these two devices, we can basically treat the whole spectrum — from soft plaque, restenotic lesions, to calcified vessels — with 4 Fr sheath access.
The short Flexor sheath and Check-Flo catheter introducer (both Cook Medical) are helpful 4 Fr devices. You can use standard, low-cost 13 cm and 23 cm 4 Fr sheaths (Merit) and 45 cm, 55 cm, 70 cm, 100 cm, and 110 cm 4 Fr sheaths (Cook Medical). There are a wide variety of .014-inch, .018-inch, and .035-inch wires and catheters that are 4 Fr-compatible. There are also many balloons available in this size (Table 1); for example, one could use a 5 mm x 200 mm balloon over the wire. For stenting, a coronary drug-eluting stent (DES) would be appropriate, albeit off label. All coronary drug-eluting stents are 4 Fr-compatible, and regularly used in the proximal tibial arteries. Biotronik now has the 4 Fr-compatible nitinol peripheral stent.
Dr. Mustapha: Do you feel you are getting adequate treatment in the superficial femoral artery (SFA) with a 1.25 mm solid device?
Dr. Julien: The Diamondback 1.25 mm device is ideal for tibials. For SFAs, sometimes my goal is to simply get a channel to allow passage of devices, such as a balloon. Other times, my goal is to create a larger channel. Increased lumen diameter can be gained by increasing the orbital speed and by increasing the number of passes (Figure 1).5 There may be cases where a larger device may be needed.
Dr. Mustapha: Which vessels do you access with 4 Fr sheaths? Under what circumstances do you have to upsize to a larger sheath and how often do you have to upsize your sheath in order to complete the procedure?
Dr. Julien: I am extremely comfortable puncturing radial, brachial and common femoral arteries, and pedal vessels with a 4 Fr sheath. Occasionally, I access the SFA or profunda femoral.
Upsizing may be necessary in the following circumstances: use of a 9 mm or greater balloon, specialty balloons (e.g. Kevlar, drug-coated, Chocolate, scoring, Cutting), iliac interventions, and placing a stent without the use of the bareback technique. It is also done when the operator wants or needs to upsize to larger atherectomy devices. The need to upsize is uncommon, less than 20% of the time, in my experience.
Dr. Mustapha: Why do you think 4 Fr access has not become standard of care for endovascular procedures? Are there advances in technology that would be helpful to facilitate 4 Fr access?
Dr. Julien: There could be a number of reasons. Many operators reflexively use a 6 Fr access because they are simply taught to use larger sheaths and are unaware of the viability to perform procedures via 4 Fr. Most operators do not think they can accomplish everything they may need to with the 4 Fr, so they start with a sheath that will accommodate every possible scenario.
It would be helpful to have smaller sheath stent delivery systems and smaller drug-coated balloons. Also, the ability to use larger atherectomy devices in 4 Fr would be a great advancement. Devices for 4 Fr treatment of iliac arteries would be very helpful as well. Finally, devices that would allow us to reach the tibials from a radial artery puncture would be useful, so we could do more 4 Fr radial access to treat CLI.
Dr. Mustapha: Do you believe a clinical study is warranted to demonstrate the safety and efficacy of endovascular procedures via 4 Fr access?
Dr. Julien: I do, especially to convince those who have not adopted a 4 Fr approach. I would suggest a registry of perhaps 100 patients where 4 Fr endovascular procedures are performed in an office interventional suite. The BIO4AMB trial was recently completed in France, which is Biotronik’s 4French for AMBulatory Peripheral Intervention trial.4 It is a multicenter, controlled trial comparing 4 Fr vs 6 Fr femoral access for endovascular treatment of lower-extremity peripheral artery disease in an ambulatory setting.
In my clinical practice, I have had great success with the 4 Fr approach, with minimal adverse outcomes and minimal bleeding complications. I have also had success with low-profile laser (0.9 and 1.4 mm) and orbital atherectomy devices. We have been doing 4 Fr access for approximately 6 years, and usage has gradually increased to the point we now complete over 80% of our cases using 4 Fr access. We have a very high portion of patients, around 80%, with CLI, so we see lots of tibial disease. Therefore, we have a disproportionately high percentage of our population that is 4 Fr-compatible. We are currently in the process of finalizing the design of a 100 consecutive case 4 Fr prospective registry.
Dr. Mustapha: Are there any other recent access site changes that you are excited about?
Dr. Julien: I think radial access offers an interesting alternative to treat PAD with minimal access site complications. We use it with regularity for iliac, common femoral, and profunda femoral interventions. However, it is a developing area, with only limited treatment options below the groin at this time.
Another helpful area is thin-walled sheath design (Slender sheaths [Terumo]), which allows standard SFA stenting and larger atherectomy devices to be performed from pedal access through 6 Fr-compatible sheaths that are equal in outer diameter to older 5 Fr sheaths.
*Note for Figure 1: The IFU can be found online at https://csi360.com/products/diamondback-360-peripheral-orbital-atherectomy-system/
Disclosure: Dr. William Julien reports he is a Past President and co-Founder of the Outpatient Endovascular and Interventional Society, and that he is a consultant and gives in-office courses for Cook Medical and CSI, Inc.
Dr. Julien can be contacted at firstname.lastname@example.org.
Dr. Mustapha can be contacted at email@example.com.
- Mustapha J, Gray W, Martinsen BJ, Bolduan RW, Adams GL, Ansel G, Jaff MR. One-year results of the LIBERTY 360 study: evaluation of acute and midterm clinical outcomes of peripheral endovascular device interventions. J Endovasc Ther. 2019; 26(2): 143-154.
- Stavroulakis K, Borowski M, Torsello G, Bisdas T; CRITISCH Collaborators. One-year results of first-line treatment strategies in patients with critical limb ischemia (CRITISCH Registry). J Endovasc Ther. 2018; 25: 320-329.
- Bosiers M, Deloose K, Callaert J, et al. 4-French-compatible endovascular material is safe and effective in the treatment of femoropopliteal occlusive disease: results of the 4-EVER trial. J Endovasc Ther. 2013; 20(6): 746-756.
- BIOTRONIK 4French for AMBulatory Peripheral Intervention (BIO4AMB). Sponsor: Biotronik AG. ClinicalTrials.gov. Available at: https://clinicaltrials.gov/ct2/show/NCT03044002. Accessed July 16, 2019.
- Diamondback 360 Peripheral Orbital Atherectomy System. CSI360. Available at: Available online at https://csi360.com/products/diamondback-360-peripheral-orbital-atherectomy-system/. Accessed April 30, 2019.