Cath Lab Digest - September 2007 - (Page 15)

15 widely. In aortoiliac and femoropopliteal disease, technical success is reported from 71–87%.10,17 Several factors, such as lesion length, calcification, operator experience, and patency of runoff vessels may influence success rates. Reentry catheters. In cases where the true lumen cannot be reentered distally from the subintimal space with the guidewire, reentry devices may be an option. Two devices are available, the Pioneer catheter (Medtronic Vascular) and the Outback (Cordis Corporation, Miami, FL). Both devices are best suited for vessels that are not heavily calcified and have a well-visualized distal vessel. Briefly, the Pioneer has two .014” wire ports, one with a hollow core nitinol needle. The needle is rotated towards the vessel lumen using intravascular ultrasound guidance (Volcano Corp., Rancho Cordova, CA). The needle is advanced into the lumen and a .014” wire is advanced and secures intraluminal position as the device is withdrawn. With the Outback catheter, fluoroscopic imaging is used to direct a 22-gauge cannula for distal vessel entry. Orthogonal angiography and a fluoroscopic marker provide orientation of the tip toward the reentry site and an angled nitinol needle is advanced into the vessel into the true lumen (Figure 3). Early small series showed favorable outcomes with procedural success in the absence of complications for both devices.18–20 A retrospective review of 52 consecutive peripheral CTO cases at a single institution showed that procedural success was 100% with the availability of the Pioneer catheter, compared to 76% prior to having a reentry device with similar complication rates.21 Reentry devices are also very effective for lesions that failed prior guidewire attempts. In a study of 87 previously attempted CTOs (58 iliac and 29 SFA), a reentry device, either Pioneer or Outback, resulted in procedural success in 24 lesions that could not be reentered with a wire on second attempt. No bleeding was reported at the site of lumen reentry, although 4 cases of PTA site bleeding were observed, all in iliac interventions. These were treated with covered stents in 2 cases and uncovered stents in the others.22 In summary, the reentry catheters will allow endovascular specialists to pursue more difficult CTOs. A caveat is that caution must be exercised, particularly in the aortoiliac vessels, due to the possibility Figure 2. A 72-year-old male with chronic stable angina, hypertension, dyslipidemia, and laryngeal cancer had progressive, lifestyle-limiting left calf claudication and an ABI of 0.43. Examination suggested femoropopliteal and infrapopliteal disease. The femoropopliteal lesion by CT angiography was short (see Figure 1). The intervention was performed via the contralateral femoral artery approach using a 7-Fr crossover sheath. The occlusion was well-collateralized (a). The lesion was crossed with an angled Glidewire supported by a glide catheter and a distal injection (b) via the glide catheter (black arrow) confirmed intraluminal position. After balloon angioplasty (c), there was a suboptimal result. The lesion was treated with a self-expanding nitinol stent (d). The mean gradient across the lesion decreased from 29 to 3 mmHg. patients with PAD that was developed by members of multiple specialties, including cardiology, vascular surgery, interventional radiology and vascular medicine, address the endovascular treatment of claudication and critical limb ischemia (CLI).10 For patients with lifestyle- or vocation-limiting claudication and nonresponsive to exercise or pharmacologic therapy, endovascular intervention is the preferred revascularization strategy for TASC type A lesions. No specific recommendations are given based on other TASC types, but intervention is acceptable if there is a favorable riskbenefit ratio. The guidelines, therefore, leave most of the decisions regarding the appropriate revascularization strategy to the treating physicians and endovascular specialists. Many of the approaches and devices discussed in this review can be used to safely and successfully treat TASC type D lesions that were previously in the domain of the surgeon. There remains an issue of durability for long CTOs, particularly infrainguinal; therefore, patient selection and close follow up with reintervention, if needed, are keys to optimal long-term patency. Techniques for Crossing CTOs Standard guidewire manipulation. Standard guidewire recanalization should initially be attempted, even for long, occlusive lesions. Although the inability to remain intraluminal or reenter the true lumen distally are the main reasons for failure of this technique, there is still a relatively high chance of success. For aortoiliac lesions, an ipsilateral retrograde femoral approach is usually the simplest, but an alternative approach from contralateral femoral or brachial access may be needed. For superficial femoral artery (SFA) lesions, a contralateral femoral approach with a crossover sheath is usually needed, but for more distal lesions such as infrapopliteal, an antegrade femoral approach may be preferable, so that device torquability and pushability is optimized. In difficult cases, an alternative access site or bilateral approach to the CTO should be considered.11–15 The most straightforward strategy for approaching CTOs is the use of the combination of a hydrophilic guidewire and a low-profile support catheter, such as a 4-Fr or 5-Fr Glide Catheter (Terumo Medical Corp., Somerset, NJ) or a .035” Quick Cross (Spectranetics, Colorado Springs, CO). A .035” Glidewire® (Terumo Medical Corp.) has a hydrophilic coating and a solid core that can often penetrate the proximal cap of the occlusion. An angled Glidewire is usually preferred, due to its steerability, but a straight Glidewire in a straight or angled support catheter is another option if initial attempts fail. Once the proximal occlusion is penetrated, the wire and support catheter are advanced in a stepwise fashion, with the wire tip straight or in a narrow loop configuration. Angiography can be performed through the sheath if it is required to assess wire position in relation to the vessel distal to the CTO, but often vessel calcification or road map imaging can be used as a landmark. Injections through the support catheter are discouraged, as passage is often partially subintimal, and contrast staining and compression of the lumen can occur. Either an intralumenal or entirely subintimal approach can be used.16 When the wire is at the distal edge of the occlusion, reentry into the true lumen is the next step. The creation of subintimal dissection distal to this point should be minimized, so as to avoid extending the lesion length or compromise collateral flow. If attempts with the .035” guidewire fail, stiff .018” or .014” wire designed for CTOs may be successful. Once the wire is in the distal true lumen, the support catheter is advanced and a contrast injection can be performed through the catheter to confirm location and measure distal pressure (Figure 2). The dilation component of the procedure can be completed with a number of devices, most commonly balloon angioplasty (PTA), with selfexpanding nitinol stents for suboptimal PTA results. Alternatively, laser or atherectomy devices can be used, although this approach does not achieve substantial luminal enlargement in larger arteries. The success rate for crossing CTOs with the guidewire technique varies

Table of Contents Feed for the Digital Edition of Cath Lab Digest - September 2007

St. Dominic Hospital The Genous Bio-engineered R Stent Percutaneous Treatment of Peripheral Arterial Chronic Total Occlusions: Device Options and Clinical Outcomes Contents Clinical Editor’s Corner Percutaneous Revascularization of Peripheral Chronic Total Occlusion — Which Patients, Why, and How? Myocardial Infarction and Syncope: A Manifestation of the “Raynaud-Prinzmetal Syndrome”? Essential Technical Components of the Transradial Approach If You Build It, Will They Come? Evidence-Based Medicine with Drug-Eluting Stents Back to School: The Value of Education in Cardiovascular Services The ACVP Standards and Competencies: Are You Using Them Effectively? What Do You Think? My Experience with Fibromuscular Dysplasia and Stroke A Brief Review of Fibromuscular Dysplasia Letter to the Editor A Look at On-the-Job Training: Perceptions, Reality and Our Profession Doing the Wave: Inventory Management with RFID The Ten-Minute Interview with… Paul Pinsker, RCIS CLD’s Annual Salary Survey Harrisburg Area Community College Volunteer Survey CEU Education Center SICP* Section Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab Clinical & Industry News

Cath Lab Digest - September 2007

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