Several true lumen re entry devices
Several true lumen re-entry devices have been introduced into the market, including the Outback catheter, allowing fluoroscopically controlled true arterial lumen re-entry after subintimal guidewire passage. A recent retrospective review reported a successful re-entry rate of 91% in 11 patients with aortoiliac CTO after traditional methods had failed. Also, the Pioneer catheter, using a built-in, cross-sectional intravascular ultrasound (IVUS7) transducer to guide the puncture into the true lumen. Krishnamurthy et al reported this device to be technically successful in all of their 11 patients with unilateral iliac occlusions. Additionally, the Frontrunner catheter, using blunt microdissections inside the plaque, allows passage of the guidewire through the lesion and adjunctive angioplasty. Mossop et al reported a recanalization success rate of 88% in 24 iliac CTOs, with a true lumen re-entry catheter required in 35% of these cases. Although the overall reported technical success rate of using these re-entry devices is high, it stavudine is limited by a high catheter cost and the need for additional equipment, such as an intravascular ultrasound. Alternative methods of true lumen re-entry without the use of the above-mentioned devices had also been previously reported. Murphy et al described a case report of successful re-entry with the aid of a curved,18-gauge needle to puncture through the subintimal space with an occlusion balloon inflated in the iliac stump via contralateral femoral access. Sharafuddin et al reported the coaxial use of a 21-gauge long Chiba needle in a 14-gauge Rosch–Uchida transjugular intrahepatic portosystemic shunt system to achieve re-entry, demonstrating success in nine of 11 (82%) patients. Gastaldo et al used a modified 18-gauge trans-septal needle with a 21-gauge tip to recanalize the true lumen with success in 13 of 15 (86.6%) patients with chronic iliac artery occlusion. The causes of re-entry failure were primarily attributed to vessel calcification that precluded using a fine needle for through-puncture. Thereafter, Sharafuddin et al suggested the use of a larger needle system such as the 5-F sharp cannula in the Rosch–Uchida kit or using the 16-gauge Colapinto needle itself. In a recent study, Smyth and Hadziomerovic reported the use of a 5-F metal cannula from an 8-F drainage kit with technical success in all of their 12 patients but with a severe complication of vascular perforation at aortic bifurcation in one patient. In our series, we successfully used a 16-gauge needle for re-entry puncture in all 10 of our patients. It appeared that a larger needle can achieve a higher re-entry success rate, but the complication of vascular perforation must be cautioned. Of the above re-entry techniques, all punctures were directed by fluoroscopic guidance. Cho et al considered that fluoroscopy would not be as beneficial if used alone in this kind of complicated intervention for completely occluded aortoiliac disease. Our study showed that the re-entry site of the abdominal aorta in a subintimal angioplasty may be varied and inconsistent, as demonstrated on the cone-beam CT images. The re-entry site can be anywhere from 90° to 180° different from the supposed direction (i.e., left side iliac occlusion with re-entry point at the right lateral wall of the aorta). Although multiview fluoroscopy has been reported to be successful in guiding aortic re-entry, a wrong-direction puncture in the aorta may lead to major complications. Cone-beam CT is now available as standard equipment in many angiographic suites. Although cone-beam CT is not real-time imaging similar to intravascular ultrasound, it does provide an accurate relative position of the needle tip to the aorta, which makes interventionists more capable of accomplishing aortic re-entry, even with the use of a larger needle. In fact, it eliminates the need for expensive commercially available re-entry devices.