Cath Lab Digest - September 2007 - (Page 18)

CLINICAL REVIEW SEPTEMBER lesions vary depending on several factors, such as location. In iliac occlusions with a mean length of approximately 9 cm and treated with excimer laser and stenting, primary patency rates were 84% at 1 year and 76% at 4 years.40 Evaluations of drug-eluting stents in the peripheral arterial circulation have been performed but are limited. In the SIROCCO I and II trials comparing bare metal to sirolimus-eluting stents in obstructive SFA disease, 57% and 66.7% of patients had occlusions. The bare-metal nitinol self-expanding stent arm had a binary restenosis rate of 7.7% at 6 months and overall no benefit was observed with the drugeluting stent.41,42 Late follow-up of TASC type C lesions in these studies showed binary restenosis of 21.1% by duplex ultrasound in the bare metal stent arm and again, no benefit in the sirolimus stent arm.43 Another option in the future may be the use of stent grafts. The Hemobahn stent-graft was prospectively evaluated in 52 patients with mainly occlusions of the SFA. The mean length of vessel segments covered was 10.9 cm. Technical success was 100%, but distal embolization was observed in 4 patients and an arteriovenous fistula in one. Primary patency rates at 24 months were favorable at 74.1%, with an assisted patency of 80.3%.44 Further data are needed to determine if stent grafts offer an advantage over uncovered stents. Excimer laser. The excimer laser was discussed above as an alternative technique for crossing CTOs. The laser can also be used for debulking. As a stand-alone therapy for SFA CTOs, the excimer laser resulted in a 1-year primary patency of 33.6% in one study, with assisted primary patency of 65.1%.28 In the randomized controlled Peripheral Excimer Laser Angioplasty (PELA) trial, laser debulking followed by PTA was compared to PTA alone for the treatment of long SFA occlusions. The laser group less often underwent stenting and had lower complication rates with less embolization; however, 1-year patency rates were equivalent. Overall, use of the excimer laser does not appear to improve procedural durability over PTA and stenting. Excision atherectomy. Debulking can also be accomplished with the SilverHawk atherectomy catheter (FoxHollow, Redwood City, CA). The SilverHawk is a monorail catheter requiring a .014” guidewire, with a forward-cutting carbide cutting blade that rotates at 8,000 rpm when turned on. As the catheter is advanced through the lesion, plaque is excised and collected into a nose cone. The SilverHawk can remove a large amount of tissue, but long lesions may be time-consuming to treat, as they require multiple passes across the lesion with intermittent clearing of the nosecone. The potential for distal embolization has also been recognized. Atherectomy alone can be performed with this device. To date, there are no randomized trials comparing a temperature of -10°C. Following a brief treatment, the gas is removed and the balloon is warmed prior to removal. Limited data are available on the use of cryoplasty for CTOs at this time, but in a prospective registry of 102 patients with SFA PAD, 14.7% had total occlusions (< 10 cm). Overall, 85.3% were treated with cryoplasty alone (67% of CTO patients) and the remainder received stents. The clinical patency rate at 9 months was 82.2%, with primary assisted patency of 94%.46 A 3-year follow up of a subset of these patients showed main- References 1. National Center for Health Statistics, National Hospital Discharge Survey, http://www.cdc.gov/nchs/about/major /hdasd/nhds.htm. 2. Dormandy JA, Rutherford RB. Management of peripheral arterial disease (PAD). TASC Working Group. TransAtlantic Inter-Society Consensus (TASC). J Vasc Surg 2000;31:S1–S296. 3. Smith FB, Lee AJ, Fowkes FG, et al. Variation in cardiovascular risk factors by angiographic site of lower limb atherosclerosis. Eur J Vasc Endovasc Surg 1996;11:340–346. 4. Barretto S, Ballman KV, Rooke TW, Kullo IJ. Early-onset peripheral arterial occlusive disease: Clinical features and determinants of disease severity and location. Vasc Med 2003;8:95–100. 5. Scotland RS, Vallance PJ, Ahluwalia A. Endogenous factors involved in regulation of tone of arterial vasa vasorum: Implications for conduit vessel physiology. Cardiovasc Res 2000;46:403–411. 6. Bull PG, Mendel H, Hold M, et al. Distal popliteal and tibioperoneal transluminal angioplasty: Long-term follow-up. J Vasc Interven Radiol 1992;3:45–53. 7. Dorros G, Jaff MR, Dorros AM, et al. Tibioperoneal (outflow lesion) angioplasty can be used as primary treatment in 235 patients with critical limb ischemia: Five-year follow-up. Circulation 2001;104: 2057–2062. 8. Soder HK, Manninen HI, Jaakkola P, et al. Prospective trial of infrapopliteal artery balloon angioplasty for critical limb ischemia. J Vasc Interven Radiol 2000;11:1021–1031. 9. Perazella MA, Rodby RA. Nephrogenic systemic fibrosis: A devastating complication of gadolinium in patients with severe renal impairment. Vascular Disease Management 2007;4:45–47. 10. Hirsch AT, Haskal ZJ, Hertzer NR, et al. ACC/AHA Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): A collaborative report from the American Associations for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (writing committee to develop guidelines for the management of patients with peripheral arterial disease) — summary of recommendations. J Vasc Interven Radiol 2006;17:1383–1397. 11. Cutress ML, Blanshard K, Shaw M, et al. Retrograde subintimal angioplasty via a popliteal artery approach. Eur J Vasc Endovasc Surg 2002;23:275–276. 12. Saha S, Gibson M, Magee TR, et al. Early results of retrograde transpopliteal angioplasty of iliofemoral lesions. Cardiovasc Interven Radiol 2001;24:378–382. 13. Spinosa DJ, Leung DA, Harthun NL, et al. Simultaneous antegrade and retrograde access for subintimal recanalization of peripheral arterial occlusion. J Vasc Interven Radiol Although treatment of CTOs remains challenging and requires patience and knowledge of many devices, clinical success leads to significant improvement in the quality of life and for some, limb salvage, and is therefore rewarding. atherectomy alone or with adjunctive PTA to PTA and/or stenting. Data are available from the Treating Peripherals with SilverHawk Outcomes Collection (TALON) registry, which is a multicenter, prospective observational database of 601 consecutive patients (748 limbs) with symptomatic lowerextremity PAD treated by plaque excision with the SilverHawk catheter. Mean lesion lengths above and below the knee were 62.5 ± 68.5 mm and 33.4 ± 42.7 mm, respectively. Procedural success was 97.6%, 73.3% of lesions were treated with atherectomy alone, and only 6.3% were stented. The 12-month rate of survival free of TLR was 80%. Increasing lesion length predicted higher TLR rates.45 tained durability.47 It is unclear if cryotherapy is effective at treating longer or more complex CTOs and how it compares to therapy with PTA and/or stenting. Conclusion In summary, peripheral CTOs remain one of the most challenging lesions for the endovascular specialist. The device armamentarium continues to expand with the availability of reentry devices, microdissection catheters, excimer lasers, and potential additions, such as ultrasound therapy. In addition to devices, subintimal angioplasty and utilization of multiple arterial access sites have continued to increase the rate of crossing a CTO. Although durability remains an issue, particularly in the SFA, we need to design trials that will determine optimal therapy, including the possible use of debulking with laser or atherectomy or vascular remodeling with cryoplasty. The roles of drug-eluting and covered stents are also unknown at this time. Although treatment of CTOs remains challenging and requires patience and knowledge of many devices, clinical success leads to significant improvement in the quality of life and for some, limb salvage, and is therefore rewarding. Cryoplasty Cryoplasty, a combination of angioplasty and cold therapy, was developed to target mechanical injuryinduced arterial restenosis. The potential advantages are a less medial injury and the stimulation of smooth muscle cell apoptosis, which may lead to positive vessel remodeling. Cryotherapy with liquid nitrous oxide is delivered via the PolarCath balloon (Boston Scientific, Maple Grove, MN). During balloon inflation, the liquid nitrous oxide expands into gas and the balloon surface temperature is lowered to http://www.cdc.gov/nchs/about/major/hdasd/nhds.htm

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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