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The patient is a 83-year-old diabetic woman with a non-healing ischemic ulcer of the plantar aspect of her left foot, in spite of aggressive wound care management. Non-invasive vascular tests revealed incompressible ankle vessels and toe pressures less than 25 mm Hg. An angiogram of the left lower extremity showed a long occlusion of the superficial femoral artery, reconstitution of a small but patent popliteal artery, and a single anterior tibial arterial runoff (Figure 1). Attempt at wire traversal of the SFA occlusion was not initially successful, due to subintimal passage of the wire and inability to re-enter the reconstituted true lumen of the popliteal artery.
The Outback® Re-Entry Catheter (LuMend, Inc., Redwood City, CA) (Figures 2A–B) is a single lumen catheter designed to facilitate access and positioning of a guide wire within the peripheral vasculature, from a remote vascular entry site. A control knob, a rotating hemostasis valve (RHV), a catheter shaft with a distal nosecone, and a distal guide tip comprise the major element of the device. The distal curved tip cannula consists of a controllable nitinol sharp needle, activated via the proximal end of the catheter and used to puncture the true lumen of a vessel, under controlled fluoroscopic guidance. Upon proximal retraction, the cannula’s curved tip is positioned coaxially within the nosecone of the catheter. Under this configuration, the catheter may be tracked over a guide wire to the selected vascular target site. The guide wire is then retracted into the cannula, allowing the curved cannula needle tip to be advanced from the nosecone distal end into the target vessel (Figure 3A). Upon proper placement of the cannula tip, the guide wire may be advanced through the cannula and into the desired vascular site (Figure 3B). The cannula tip is subsequently retracted into the nosecone, and the catheter is proximally retracted, leaving the guide wire in place in the vasculature. A 5 French catheter is then tracked over the wire and advanced to the level of the reconstituted popliteal artery, to confirm intraluminal position (Figure 3C). The occlusion was then treated with 3 self-expanding Smart® stents (Cordis Endovascular, Warren, NJ) (Figures 4A-D). At 3 months, the ulcer was healed and the stents were patent by duplex ultrasonography.
Technical success of a percutaneous endovascular procedure is predicated on the successful placement of a guidewire in the true lumen beyond the lesion. Unpredictable sub-intimal passage of a guidewire requires the endovascular specialist to successfully re-enter the true lumen of the artery to treat the occlusion. At times, this re-entry process can be technically challenging, as well as time- and resource-consuming. Gaining rapid and reproducible true lumen access beyond the lesion is one of the keys in achieving high procedural success rates, especially in long femoral popliteal arterial occlusions. The Outback Re-Entry catheter has proven to be an effective, simple and safe device for predictable re-entry into the true lumen of the artery. This advancement in technology should broaden the opportunity to successfully treat patients with peripheral occlusive disease who traditionally are not considered candidates for percutaneous, less invasive catheter interventions.
Dr. Mewissen discloses that he provides consulting services to LuMend, Inc. He can be reached at mark.mewissen@aurora.org
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