New Techniques

Reentry-Catheter Assisted SAFARI Technique

Zaheed Tai, DO1 and Arthur Lee, MD2

Zaheed Tai, DO1 and Arthur Lee, MD2

From 1Winter Haven Hospital, Lakeland, Florida; and 2The Cardiac and Vascular Institute, Lakeland, Florida. 

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 September 15, 2014, provisional acceptance given December 4, 2014, final version accepted January 2, 2015.

Address for correspondence: Zaheed Tai, DO, Winter Haven Hospital, Lakeland, FL. Email:

Abstract: Reentry catheters have become an important tool in the treatment of chronic total occlusion of the peripheral vasculature. Their use has been demonstrated in the treatment of aortoiliac disease as well as femoropopliteal disease. Success rates may vary depending on operator experience and lesion characteristics, but in general are reported to be around 85% in facilitating reentry. In the event of reentry failure, alternative strategies may be required to achieve procedural success. We describe an alternative strategy to achieve success with the use of Outback and Pioneer reentry catheters when initial reentry fails. 

Reprinted with permission from J Invasive Cardiol. 2015;27(7):E146-E152.

Key words: chronic total occlusion, superficial femoral artery, peripheral arterial disease


Chronic total occlusion of the superficial femoral artery (SFA) may occur in 40% of patients with symptomatic peripheral arterial disease (PAD).1 Recent advances in endovascular therapy have resulted in an endovascular-first approach in the majority of these patients. Antegrade recanalization strategies include the true-lumen crossing approach (possibly facilitated by a crossing device) and the subintimal approach. With subintimal recanalization or percutaneous intentional extraluminal recanalization (PIER), true-lumen reentry is achieved with either a hydrophilic guidewire or the use of a reentry device (Pioneer [Volcano Corporation] or Outback [Cordis Corporation]). Despite the utilization of these devices, failure to achieve luminal entry occurs approximately 15% of the time in the femoropopliteal region.2 In these situations, retrograde access utilizing pedal access, popliteal access, or via SFA transcollaterals can facilitate procedural success. Botti et al demonstrated the feasibility of treating critical limb ischemia (CLI) with percutaneous transluminal angioplasty (PTA) alone in a series of 6 patients with direct tibial access; however, disease complexity may warrant additional treatment utilizing a 6 French (Fr) sheath, which may not be feasible in the tibial vessels. When the retrograde wire fails to enter the true lumen, the subintimal arterial flossing with antegrade retrograde intervention (SAFARI) technique may be required. In cases of diffuse disease, long lesions, or heavily calcified lesions, the two subintimal planes may not connect or result in extension of the dissection plane well beyond the intended point of reentry. The double-balloon technique is one alternative to rescue the retrograde wire.3-5 We report an alternative technique utilizing a reentry catheter to “connect” the two subintimal planes in challenging chronic total occlusions (CTOs) that were initially unsuccessfully recanalized through conventional femoral arterial access and use of a reentry catheter. To prevent propagation of the dissection plane or achieve reentry in the infrapopliteal region, we utilized a retrograde access and successful retrograde balloon puncture with the reentry catheter. 

Case #1

A 61-year-old male with a history of hypertension, hyperlipidemia, diabetes, type-I aortic dissection with repair, and continued tobacco abuse presented with left lower-extremity gangrene of the 4th and 5th digits. Resting ankle-brachial index (ABI) was 0.33 on the left lower extremity. He was scheduled for amputation; however, there was concern of inadequate wound healing given the resting ABI. Therefore, he was referred for angiography and possible revascularization. Angiography revealed a heavily calcified and tortuous iliac system (Figure 1A) that was patent and 100% occluded left SFA with reconstitution in the peroneal (Figures 1B and 1C). An initial attempt using a contralateral approach with a 7 Fr Destination sheath (Terumo Corporation) and the Crosser device (Bard Peripheral Vascular) was unsuccessful. A stiff Glidewire (Terumo Corporation) and a 0.035-inch Quick-Cross catheter (Spectranetics) were also unsuccessful. Both attempts failed as a result of failure to penetrate the proximal cap. The left brachial approach was also attempted; however, there was tortuosity (secondary to aortic dissection repair) and poor support from this access point as well. A surgical consultation was obtained; however, the patient was not considered an ideal candidate for surgery, secondary to comorbidities and poor run-off. Therefore, he was brought back for another attempt. A contralateral approach was used with a 7 Fr, 45 cm Destination sheath advanced into the left common femoral artery. This time, a Wildcat catheter (Avinger) was used with a Juicebox (Avinger). We were able to penetrate the proximal cap and advance the catheter about 30 mm beyond the cap, but any further attempt to advance the system resulted in the Destination sheath backing out. Using a stiff Glidewire and 0.035-inch Quick-Cross catheter, the wire was advanced slightly further to the mid-SFA, but could not be easily advanced any further secondary to heavy calcification and poor support. Therefore, we utilized a retrograde approach to try and complete the procedure. Using angiographic guidance, the peroneal artery was accessed with a 4 Fr micropuncture sheath. Using a 0.018-inch Quick-Cross and Astato 30 wire (Asahi Intecc), we advanced in a retrograde manner subintimally into the popliteal. The retrograde Quick-Cross was then changed to a CXI support catheter (Cook Medical) with slightly further retrograde advancement. From above, the antegrade Quick-Cross was also changed to a CXI catheter and the stiff Glidewire to a Glidewire Advantage (Terumo Corporation). Unfortunately, there was difficulty advancing into the same plane as the retrograde wire. Leaving the antegrade wire in place, a second wire was advanced into a different plane to the level of the popliteal artery. Initial attempts to use the Outback reentry catheter to cannulate the retrograde subintimal lumen were unsuccessful. We then took a 3.0 x 80 mm Coyote balloon (Boston Scientific) and advanced it in a retrograde fashion to the distal popliteal-tibioperoneal trunk and inflated at high pressure. The Outback was advanced from the antegrade approach to the same level as the retrograde balloon (Figure 1D), and was then used to rupture the balloon (Figure 1E), and the Pilot 200 wire (Abbott Vascular) passed into the balloon (Figure 1F) and then externalized with removal of the retrograde balloon. A series of balloon inflations were then performed with a 3.0 x 220 Coyote, 4.0 x 220 Coyote, 4.0 x 100 AngioSculpt (AngioScore, Inc), and 6.0 x 200 Vascutrak (Bard Peripheral Vascular). Following predilation, multiple stents were placed distal to proximal: 4.0 x 100 Supera (IDev Technologies), 5.0 x 120 Supera, 5.0 x 120 Supera, and 5.0 x 80 Supera. The peroneal sheath was removed after antegrade wiring and a 3.0 x 220 Coyote was inflated to achieve hemostasis with two 3.5-minute inflations (Figure 1F). The patient tolerated the procedure. He underwent removal of the gangrenous digits and had successful wound healing at follow-up (Figures 1H and 1I).

Case #2

 A 53-year-old male with a history of diabetes, hypertension, hyperlipidemia, end-stage renal disease on hemodialysis, and peripheral vascular disease with previous left below-the-knee amputation presented with a chronic ulcer of the right lower-extremity and dry gangrene of the 4th and 5th digits. The patient was scheduled for amputation; however, given concerns about wound healing, he was referred for angiography and possible revascularization. Angiography demonstrated a calcified and occluded anterior tibial and peroneal artery with a focal calcific stenosis of the distal posterior tibial artery (Figures 2A and 2B). The left groin was accessed and a 6 Fr, 90 cm Destination sheath was placed in the right popliteal. After administration of heparin, a Runthrough wire (Terumo Corporation) was passed distally into the posterior tibial and exchanged for a Viper Wire (Cardiovascular Systems, Inc) through a 0.014-inch Quick-Cross. A 1.25 mm crown was then used to perform atherectomy with residual 50% stenosis. A 2.5 x 20 AngioSculpt was then inflated at 6 atm for 3 minutes with brisk flow into the plantar artery and collateral filling of the distal anterior tibial. In order to improve direct flow to the foot, the anterior tibial artery was revascularized. Retrograde access was obtained with a 4 Fr sheath. The vessel was wired initially with a 0.014-inch, 30 g Victory wire (Boston Scientific), then a V18 wire (Boston Scientific). Both were unsuccessful in crossing retrograde into the proximal true lumen. An antegrade approach also resulted in subintimal entry with failure to reenter the same plane as the retrograde wire. A double-balloon technique (confluent balloons or retrograde/antegrade kiss) was unsuccessful using two 2.0 balloons (retrograde and antegrade). A 0.035-inch Glidewire was also attempted from a retrograde approach, but failed to reenter at the proximal cap, and further advancement proximal likely would have resulted in retrograde extension of the dissection plane into the popliteal region or further. We therefore advanced a 2.5 x 100 Coyote balloon from the retrograde sheath to the proximal anterior tibial cap and inflated it to nominal pressure. An Outback catheter was then advanced from the antegrade sheath into the proximal anterior tibial artery (Figure 2C). The retrograde balloon was then punctured and wired from the Outback (Figures 2D and 2E). The balloon with the wire inside was removed, externalizing the wire (SAFARI technique). The vessel was then dilated with a 2.5 x 200 VascuTrack. A Runthrough wire was then advanced from the antegrade sheath distal to the retrograde sheath. A 3.0 x 220 Coyote balloon was advanced and the retrograde sheath removed. Two 4-minute inflations at 4 atm achieved hemostasis (along with light external pressure). A final 4-minute inflation with the 3.0 x 220 Coyote at 6 atm was performed more proximally at the reentry site. The patient had improved flow into the distal vasculature (Figure 2F). He tolerated the procedure well and was discharged. Initial follow-up demonstrated improved wound healing; however, poor compliance (medications and follow-up) and his comorbidities (uncontrolled diabetes) eventually resulted in a below-the-knee amputation.

Case #3

 A 58-year-old smoker with a prior cerebrovascular accident developed right lower-extremity rest pain and a shallow ulceration on the lateral malleolus. He underwent initial evaluation at another institution. Angiography demonstrated a mid-SFA occlusion, with “no distal reconstitution” reported. Above-the-knee amputation was recommended for pain management and he was referred for a second opinion regarding revascularization.

Antegrade access was obtained in the right common femoral artery with ultrasound guidance. Initially, a 5 Fr Terumo sheath was placed for the diagnostic portion of the procedure. This was later exchanged for a 6 Fr, 45 cm Raabe sheath (Cook Medical). Delayed digital subtraction angiography demonstrated mid-SFA occlusion with late reconstitution of the anterior tibial origin and peroneal origin (Figures 3A and 3B).

The occlusion was approached with a 0.018-inch CXI catheter and a Treasure 12 wire (Asahi Intecc). We were able to penetrate the cap and advance through the SFA and popliteal occlusion, but went subintimal advancing in the peroneal artery. Ultrasound-guided retrograde access was obtained first in the peroneal artery and then the anterior tibial artery after the initial access was inadvertently lost. A 0.018-inch CXI catheter with a V18 wire (Boston Scientific) was advanced via the retrograde approach, but would not advance beyond the P1 segment of the popliteal artery. The wires were in close proximity, but clearly in different subintimal planes.

A 4.0 x 60 mm 18 LP balloon (Cook Medical) was advanced retrograde into the popliteal artery and a Pioneer Plus reentry catheter was positioned in the same segment from an antegrade approach (Figure 3C). The retrograde balloon was inflated and the Pioneer catheter was positioned axially using intravascular ultrasound guidance to allow puncture of the balloon with the reentry needle (Figure 3D). A Roadrunner wire (Cook Medical) was advanced into the ruptured balloon and advanced down the anterior tibial artery as the punctured balloon was withdrawn. Both were removed as a unit from the anterior tibial artery, resulting in externalization of the antegrade wire. Angioplasty and stenting of the distal SFA and popliteal artery were performed with restoration of two-vessel run-off (Figure 3E). The patient’s ulceration and rest pain resolved quickly.

Case #4

A 58-year-old male with hypertension, poorly controlled diabetes, peripheral neuropathy, chronic kidney disease, and tobacco use presented with a large deep ulcer on the right plantar surface wrapping around to the lateral aspect of the 5th metatarsal with exposed bone. He had long occlusions of the anterior tibial and posterior tibial arteries, with a patent peroneal artery that collateralized the dorsalis pedis and plantar arteries (Figures 4A and 4B). He had intervention of an occluded right posterior tibial artery (Figure 4C) with directional atherectomy 1 month prior, but with extension of the ulcer to the anterolateral aspect of the 5th metatarsal, anterior tibial artery revascularization to maximize blood flow to the foot was attempted.

Initial attempt with the Trupath wire (Boston Scientific) was unsuccessful, resulting in an arteriovenous fistula at the proximal anterior tibial bend (Figure 4D). Therefore, retrograde access was obtained via the dorsalis pedis artery using ultrasound guidance. A Treasure 12 wire with a support catheter was initially used to perform retrograde recanalization; the wire was then changed to a Hydro ST wire (Cook Medical) after intial attempts proved unsuccessful. Despite the use of different wires, retrograde attempts failed to cross into the true lumen and continued to find the subintimal space at the proximal anterior tibial bend.

A rendezvous technique was then attempted. A 2.0 x 4 cm, 14 LP was advanced from the antegrade access and a 3.0 x 2 cm, 14 LP was advanced from the retrograde approach. The balloons were inflated in an attempt to connect the two dissection planes (Figure 4E); however, this failed to connect the two subintimal planes. At this point, a Pioneer Plus reentry catheter was advanced over a Spartacore wire in an antegrade fashion and used to puncture the 3.0 x 2 cm, 14 LP balloon (Figure 4F). A Roadrunner wire was then advanced into the ruptured balloon and both were withdrawn simultaneously (advancing the wire as the balloon was withdrawn) as a unit from the dorsalis pedis access externalizing the antegrade wire (Figure 4G). A 3.0 x 20 cm, 14 LP balloon was placed from the antegrade direction and PTA was performed on the anterior tibial artery. Because of significant recoil after PTA, directional atherectomy was performed using a Turbohawk SXC catheter (Covidien) throughout much of the anterior tibial artery, while avoiding the one spot that previously had the arteriovenous fistula (Figure 4H). Final angioplasty was performed using a 4.0 x 16 cm, 14 LP with an excellent final result and brisk flow in the anterior tibial artery (Figures 4I, 4J, and 4K). Initially, the patient did well and eventually underwent a free flap, but several months later, he underwent below-the-knee amputation due to advanced osteomyelitis.


First described by Bolia et al in 1990,6 subintimal recanalization or percutaneous extraluminal recanalization is a well-established technique in the treatment of vascular occlusions. However, failure to reenter, which occurs approximately 20% of the time utilizing this approach, has been a limiting factor. In fact, the inability to reenter the true lumen after subintimal passage of the occluded segment has been reported as the primary reason for failure of the subintimal recanalization technique.7 Reentry devices are designed to function in situations in which the guidewire passes through the occlusion, but fails to reenter the true lumen distally. Although they work well, failure rates have been reported between 15%-35% of the time.2,8,9 Several factors may prevent procedural success, such as failure to cross the occlusion, heavy calcification, and inability to track the devices to the reentry point. There may also be concern about extending the subintimal space beyond the reconstitution point, which may result in compromise of a significant collateral or possible compromise of a future surgical option. Lipsitz et al reported that up to 47% of the collaterals distal to and 26% of the collaterals proximal to subintimally treated CTOs of the lower extremity are lost after angioplasty.10

When failure to reenter occurs from an antegrade approach, the retrograde approach may be utilized to achieve procedural success. The transpopliteal approach is the standard approach utilized in this situation; however, this approach can be time consuming, and limited by patient body habitus, concern about excess bleeding if utilized mid procedure (with anticoagulation on board), and the fact that repositioning of the patient into a prone position may limit the intervention to a single direction at any one time. Techniques have been described to obtain popliteal access in the prone position.11,12 Tibial access is another alternative, particularly if there is diffuse popliteal disease. This approach may be limited by utilization of a smaller sheath size and limited use of crossing devices or support catheters. Retrograde access has been shown to be a safe and effective approach to facilitate procedural success.13 However, in the event that the retrograde and antegrade lumen do not communicate, additional techniques may be required to facilitate lumen communication.

Although this technique has been described at the Leipzig interventional course (presentation by A. Schmidt, MD), cases reports in the literature involved the iliac and common femoral arteries and did not involve two subintimal planes (instead one true lumen and one subintimal plane) or utilization in the tibial vessels.14,15 In addition, some of the technical aspects and considerations have not been discussed in detail.

Technical considerations. Retrograde access. This approach is predicated on obtaining retrograde access, and may prove effective when there is a poor landing zone, diffuse calcification, or failed reentry attempts. When obtaining retrograde access, it is suggested to sedate the patient to a greater degree to avoid movement, especially if using fluoroscopic guidance. Minimize use of local anesthesia to avoid compression of the distal artery. Fluoroscopy (roadmap) or Doppler guidance is most often used to gain retrograde access to the artery, but surgical exposure has been utilized on occasion. The Doppler probe may prove cumbersome in relation to the small caliber of the artery and hinder access. Multiple sticks may result in vessel spasm, so once access is obtained and the sheath is placed, we often administer a cocktail (heparin, verapamil, and nitroglycerin). Failure to achieve access and restore flow may result in limb loss, which should be discussed with the patient prior to utilizing this approach. 

Use of the reentry catheter. Use of the reentry catheters requires a learning curve, and subtle maneuvers may increase the probability of success. First, minimize the size of the knuckle on the subintimal wire as you approximate the reconstituted vessel. Too large a subintimal space may result in the catheter “floating” in the subintimal space. Predilating the subintimal track may be necessary to facilitate catheter delivery (particularly the Pioneer, as this will avoid damage to the intravascular ultrasound crystals); avoid using a balloon larger than 2 mm. Also, use of a supportive wire with a quick taper such as the Spartacore wire will aid catheter delivery, especially for the anterior tibial bend. Otherwise, it may prolapse into the tibioperoneal trunk. Second, the retrograde balloon should be sized to the distal vessel and inflated to at least nominal pressure or higher. Use of an undersized balloon or low-pressure inflation may result in the needle deflecting off the vessel and failure to penetrate the retrograde balloon. Third, external pressure to approximate the balloon and catheter may increase the chance of balloon rupture, particularly if the subintimal space is large. Fourth, use of a longer retrograde balloon will allow advancement of a significant amount of wire, which will be easier to externalize upon withdrawal of the retrograde balloon. Fifth, if the catheter punctures the balloon but the wire fails to pass, it is possible the needle went through the balloon and contralateral vessel wall, particularly in the tibial vessels. In this case, it may be necessary to retract the needle slowly while advancing the wire until it passes easily. Once the wire is externalized with the SAFARI technique, the procedure is completed on the antegrade wire. Although safety has been demonstrated in treatment of infrapopliteal lesion,16 the most likely complication from this approach may be possible vessel perforation with the potential to develop compartment syndrome. Treatment to avoid this may include use of covered stents (JoMed stent [Abbott Vascular]), coil embolization, or external compression. 

Management of retrograde access. Do not give up distal access site until a balloon has been dilated across the reentry point, as this can be an area of difficulty in passing the balloon and is much easier if you have the wire exteriorized distally. The retrograde sheath is removed on the table with a low-pressure balloon inflation (3-5 minutes) and light external pressure to tamponade the access site. Intraarterial nitroglycerin is usually given before final angiography to minimize any spasm that may have occurred from the presence of the retrograde sheath. Retrograde access is a relatively safe approach, but must be used with caution, particularly in patients with single-vessel run-off. Procedural success will vary with operator experience, with low reported complication rates.13 These may include vessel dissection, hematoma, and occlusion. Retrograde sheath removal during the procedure allows angiographic assessment and immediate control of hemostasis.


Subintimal recanalization has provided a safe and efficacious option for patients who are poor surgical candidates with chronic critical limb ischemia. Many of these patients may have had prior surgical revascularization of some type, with scarring, diffuse disease, or heavy calcification, which may result in failure of an antegrade approach. Additional techniques such as pedal access may be required. If retrograde access is not successful in achieving the SAFARI technique, methods such as the one described here will hopefully increase the chances of success. This technique can be used in patients who may not be able to lay prone or even when disease extends to the infrapopliteal region. It allows retrograde access to the SFA while allowing the patient to remain supine. This technique is not a default approach to CTO recanalization. We utilize the reentry-assisted SAFARI as a salvage technique when retrograde access fails to enter the true lumen or the confluent balloon technique fails. These patients went on to some form of amputation, but not as a result of procedural complications. These patients had already been slated for amputation and successful revascularization resulted in limited amputations and attempts at limb preservation, at least initially. This approach may be considered when initial reentry failure occurs despite the use of dedicated catheters and dual access. 


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