The “SAFARI” technique1, or subintimal arterial flossing with antegrade-retrograde intervention, is a method for recanalization of chronic total occlusions (CTOs) when subintimal angioplasty fails. Retrograde access is usually obtained via the popliteal, distal anterior tibial artery, dorsalis pedis, or distal posterior tibial artery. We have found that the SAFARI technique offers more options for the treatment of CTO patients. The following case was performed in an outpatient cath lab.
JR is a 71-year-old man with hypertension, dyslipidemia, and chronic renal insufficiency (Cr 1.8), and is a former smoker. He presented with severe, lifestyle-limiting Rutherford class 3 claudication in the right calf, since undergoing a right knee replacement in October 2010.
In October 2011, he underwent an ankle-brachial index (ABI) evaluation revealing values of 0.36 and 1.0 on the right and left sides. Duplex ultrasound showed occlusion of the right mid-superficial femoral artery (SFA) and popliteal arteries, with monophasic flow seen in the tibial vessels. The patient was seen by a vascular surgeon, who recommended conservative management. After medical treatment and a walking program, the patient’s quality of life failed to improve. He still complained of leg pain, so at this point, we decided to proceed with revascularization.
In the past 6 months, the patient’s symptoms progressed to Rutherford class 4 rest pain and he was referred to our practice. The symptoms were crippling and the patient’s quality of life severely affected.
Angiography was performed, confirming a totally occluded right mid-SFA. Collateral flow reconstituted the tibial vessels at the origin of the anterior tibial artery. The posterior tibial artery was occluded proximally, but the peroneal artery and anterior tibial arteries were widely patent.
A discussion of continued medical therapy vs. surgical bypass vs. a percutaneous attempt at revascularization took place. Despite being told that surgical bypass with an autogenous vein might provide better long-term patency, the patient and his wife elected to have a percutaneous intervention.
Access was obtained via the right common femoral artery in an antegrade fashion with a 6 French (Fr) sheath. An S6 Crosser device (Bard Peripheral Vascular) was chosen to cross the CTO, due to the fact that the reconstitution appeared to occur at the bifurcation of the anterior tibial and tibioperoneal trunk. The goal was to avoid a subintimal situation that could potentially dissect past the ostium of the anterior tibial. The catheter crossed the proximal cap, but just above the knee joint behind the prosthesis. It took a very acute angle posteromedially and further progress ceased. We attempted to redirect the catheter towards a more anatomical path, but this led to the patient experiencing pain and most likely resulted in a local perforation.
Dorsalis pedis access (start of SAFARI technique)
Access was then obtained in the dorsalis pedis artery using ultrasound guidance and a pedal sheath placed, which was later exchanged to a 4 Fr sheath. We attempted to wire the popliteal artery in a retrograde fashion, but there was no retrograde stump, and the takeoff of the anterior tibial artery had a greater than 90-degree takeoff. This meant the retrograde wire from the pedal approach kept going into the tibioperoneal trunk, despite the use of multiple wires, including the Whisper (Abbott Vascular) and Fielder XT (Asahi) wires, and directional catheters such as the angled CXI (Cook).
At this point, we again came from the right common femoral approach with a 5 Fr KMP catheter (Cook) and angled, stiff Glidewire (Terumo). We purposely took a subintimal approach and the vessel did indeed take a strange turn behind the prosthetic knee. An extreme amount of resistance was encountered, causing not only the wire to buckle, but also the catheter. Using the prolapsed catheter over the wire, we were able to push past the occlusion behind the prosthetic knee joint. At this point, we exchanged for an 0.014” Whisper wire, placed subintimally into the tibioperoneal trunk, and placed a 2.0 mm balloon over the wire. A second 2.0 mm balloon was placed via the pedal access and was passed from the anterior tibial takeoff into the tibioperoneal trunk, overlapping the subintimal ballon from above. The balloons were inflated simultaneously and then removed. At this point, we were able to wire the true lumen of the tibioperoneal trunk with a 0.014” Whisper wire. The wire was then placed into the posterior tibial artery stump. Attempts at wiring the anterior tibial artery were unsuccessful even after ballooning the reentry site, as the site of reentry was probably distal to the takeoff of the anterior tibial artery.
A 2 mm Amplatz GooseNeck snare (ev3) was placed from the femoral access into the posterior tibial artery, snaring the wire from the pedal sheath and exteriorizing it at the femoral sheath. The wire was reversed and the entire length of the SFA and popliteal occlusion into the anterior tibial vessel was ballooned. A very resistant lesion was seen in the popliteal artery at the superior margin of the prosthesis, but this eventually expanded with high pressure.
Two 5x120 mm Supera stents (IDEV Technologies) were placed from the distal popliteal artery at the takeoff of the anterior tibial artery, back to the distal SFA with good expansion. One additional 7x150 mm Protege stent (ev3) was deployed in the mid SFA. A dissection at the ostium of the anterior tibial artery was treated with prolonged balloon inflation, using a 4x40 mm LP18 balloon (Cook), with only mild, residual stenosis.
The pedal sheath was removed while the anterior tibial artery was ballooned, which assisted with hemostasis.
Completion angiograms were obtained, showing restoration of in-line flow to the peroneal and anterior tibial arteries, with no detrimental effect seen at the site of pedal access. The antegrade femoral sheath was then removed and sealed with a Mynx closure device (AccessClosure). Total contrast use was 110 cc of Visipaque (GE Healthcare). The patient was sent home the same day. A follow-up visit four weeks later confirmed an excellent clinical response, with resolution of rest pain and claudication.
This case demonstrates the benefits of antegrade access for complex CTO intervention. We found that the antegrade technique provided greater steerability and pushability for the wires and equipment utilized in the case. While pedal/tibial access was a beneficial option, a decision to gain pedal access in a patient without tissue loss should always be made with extreme caution and informed consent. This patient had rest pain and severe, lifestyle-limiting symptoms. It is also important to become comfortable in the use of snaring wires, which allow for easy recanalization of the true lumen.
As shown herein, performing popliteal intervention when the patient has a prosthetic knee joint is difficult, but possible. The patient’s iatrogenic injury of the SFA/popliteal vessel possibly occurred during knee replacement, given an atypical pattern of occlusion, reconstitution, and vessel course behind the prosthesis, as well as the lack of significant calcification.
Orlando Marrero can be contacted at email@example.com.
Dr. Arthur Lee can be contacted at firstname.lastname@example.org.
Disclosure: Orlando Marrero, an independent consultant, reports he currently consults for IDEV Technologies as an endovascular specialist.
- Zhuang KD, Tan SG, Tay KH. The “SAFARI” technique using retrograde access via peroneal artery access. Cardiovasc Intervent Radiol 2011 Dec 1. Doi: 10.1007/s00270-011-0297-5.