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E M I N A R S I N
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A S C U L A R
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R G E R Y
27 (2014) 1–2
Available online at www.sciencedirect.com
www.elsevier.com/locate/semvascsurg
Introduction Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD), and carries with it the most grave morbidity and mortality. The term critical limb ischemia should be reserved for conditions in which circulation has dropped to such critically low levels that eventual limb loss is impending. Clinical manifestations of CLI are ischemic pain that occurs at rest, ulceration, or tissue loss/gangrene. This corresponds to Rutherford classes 4 to 6, or Fontaine stages III and IV [1]. The prognosis for patients with CLI is poor if the disease process is left untreated. Major amputation rates in the setting of arterial insufficiency, without revascularization, can be as high as 30% to 40% at 1 year [2,3]. In addition, patients with CLI carry a heavy burden of comorbidities, including smoking, hypertension, hyperlipidemia, coronary artery, and chronic kidney disease. Patients with symptomatic PAD have a 20% to 30% risk of stroke, myocardial infarction, or death, within 5 years [1,4,5]. Those with CLI carry the highest risk among PAD patients, with a greater risk of 5-year mortality than patients with symptomatic coronary artery disease or advanced malignancy [1]. The incidence of CLI in the Western world is estimated to be between 500 and 1,000 new cases/year/million persons [2]. In the United States, CLI is thought to affect 1% of the population over the age of 50 years, and double that rate in people over 70 years. With the aging population, it is thought that the number of people over 65 years of age will double by 2045, to 420% of the overall populous [5]. The incidence and prevalence of PAD and CLI may reach epidemic levels as the US population continues to age. Increasingly, a multidisciplinary approach to limb salvage has been employed in patients with CLI. This approach uses preventative care from primary care providers and endocrinologists to effectively manage diabetes. Podiatrists provide early management of diabetic ulcers and infection, with appropriate orthotic use and offloading techniques. Vascular surgeons and interventionalists offer prompt restitution of circulation when critical ischemia occurs, using traditional surgical bypass and a dizzying array of new endovascular techniques. Orthopedic surgeons contribute to the creation of functional amputations when necessary, and plastic surgeons provide tissue flap coverage to combat advanced tissue loss. This issue of Seminars in Vascular Surgery has been assembled to provide the vascular surgeon and interventionalist some organization to the multidisciplinary approach to limb salvage.
Specifically, we have focused on the issues most germane to the surgical and endovascular treatment of CLI, and the rationale behind these treatments. Experts in these areas have been asked to provide both best clinical evidence, as well as their personal approach to the concepts of limb salvage. Assessment of limb perfusion has always been a vexing problem for vascular surgeons, both assessing the need for revascularization and predicting adequate wound healing. Many of these technologies have not yet made it to the regular armamentarium of the surgeon, despite their potential utility. Drs. Benitez and Sumpio evaluate some of the current and emerging technologies in regional perfusion imaging modalities, such as hyperspectral imaging, fluorescent angiography, and laser Doppler. The many recent advances in limb-salvage techniques necessitate a better classification scheme to accurately predict amputation risks. Older schemes, such as the Fontaine and Rutherford classifications, failed to take into account the significant contribution of diabetic disease and the impact of extent of tissue loss and infection. Dr. Joseph Mills Sr provides an excellent synopsis of the new wound, ischemia, and foot infection (WIfI) classification recently developed by the Society for Vascular Surgery Lower Extremity Guidelines Committee. This system has exciting implications for prediction, as well as application in future clinical trials. As previously mentioned, the prognosis for patients with CLI can be dismal, especially in patients with no traditional revascularization options. This has led to the development of therapeutic angiogenesis, whereby angiogenic growth factors or stem cells can be use to foster new blood vessel growth and improve regional tissue perfusion. Drs. Ko and Bandyk summarize recent clinical trials using these biologic therapies and opine on their potential utility on treating CLI patients. The choice of the tibial target for revascularization has always been of critical importance. This has led to the development of the “angiosome hypothesis,” where the foot is divided into regions based on the feeding tibial arteries. In patients with tissue loss, a correlation is thought to exist between the location of the wound and the optimal vessel to treat. Drs. McCallum and Lane give evidence in favor of and against this hypothesis and its importance in guiding revascularization treatment. One of the most rapidly evolving arenas in the topic of CLI treatment has been in the area of infrapopliteal endovascular intervention. There has been an explosion of “disruptive technology” ranging from long-balloon angioplasty, drug-coated
2
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balloons, bare metal and drug-coated stents, atherectomy, and retrograde tibial access. Many of these techniques have been widely employed without clear clinical benefit. Drs. Huang and Schneider give a very balanced evaluation of these emerging technologies, along with a critical assessment of their utility. Infrainguinal bypass continues to be the gold standard for the treatment of CLI. However, these techniques increasingly become a “lost art,” as technical abilities shift toward endovascular skills. For this reason, Drs. Eichler and Causey offer their “tricks and tips” for infrainguinal bypass from the University of California San Francisco group. Their stepwise approach to the bypass procedure can help to avoid the many pitfalls of the technically challenging tibial bypass. The multidisciplinary approach to limb salvage relies on the podiatrist for treatment of complex diabetic wounds and ulcers. One of their primary techniques, often lost on vascular surgeons, is the concept of loading. Drs. Miller and Armstrong provide their techniques and innovations in offloading various orthotics, including the instant total contact cast. After a successful intervention, a structured surveillance program is critical to maintaining the patency of the target vessel or graft and the durability of limb salvage. This involves clinical evaluation, vascular laboratory testing, and timely radiologic or surgical intervention. Drs. Barleben and Bandyk give their recommendations on current surveillance protocols, critique their limitations, and give insight on when reintervention is necessary. Finally, we are pleased to have an editorial from Drs. Menard and Farber, who are the principal investigators of the ongoing BEST-CLI clinical trial. This trial evaluates best endovascular versus best open surgical management of patients in the setting of CLI. It is the only National Institutes of Health sponsored randomized clinical trial to evaluate the relative effectiveness of these two modalities in CLI in order to gain a rationale approach to their respective applications.
SU
R G E R Y
27 (2014) 1–2
It is my hope that this issue of the Seminars of Vascular Surgery will provide an up-to-date education in the management of CLI for the vascular specialist. There is little doubt that this field will continue to evolve and provide new techniques for improved limb salvage and quality of life for our patients.
re fe r en ces
[1] Norgren L, Hiatt WR, Dormandy JA, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg 2007;45(Suppl. S):S5 67. [2] Marston WA, Davies SW, Armstrong B, et al. Natural history of limbs with arterial insufficiency and chronic ulceration treated without revascularization. J Vasc Surg 2006;44:108–14. [3] Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection, awareness, and treatment in primary care. JAMA 2001;286:1317–24. [4] Selvin E, Erlinger TP. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 19992000. Circulation 2004;110:738 43. [5] Projections of the Population by Age and Sex for the United States: 2010-2050 (NP2008-T12). Table 12. Washington, DC: US Census Bureau Population Division; 2008.
Guest Editor John S. Lane III, MD, FACS Professor of Vascular and Endovascular Surgery University of California San Diego Chief of Vascular Surgery La Jolla VA Hospital La Jolla, CA
0895-7967/$ - see front matter & 2015 Published by Elsevier Inc. http://dx.doi.org/10.1053/j.semvascsurg.2015.01.005
E M I N A R S I N
V
A S C U L A R
SU
R G E R Y
27 (2014) 1–2
Available online at www.sciencedirect.com
www.elsevier.com/locate/semvascsurg
Introduction Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD), and carries with it the most grave morbidity and mortality. The term critical limb ischemia should be reserved for conditions in which circulation has dropped to such critically low levels that eventual limb loss is impending. Clinical manifestations of CLI are ischemic pain that occurs at rest, ulceration, or tissue loss/gangrene. This corresponds to Rutherford classes 4 to 6, or Fontaine stages III and IV [1]. The prognosis for patients with CLI is poor if the disease process is left untreated. Major amputation rates in the setting of arterial insufficiency, without revascularization, can be as high as 30% to 40% at 1 year [2,3]. In addition, patients with CLI carry a heavy burden of comorbidities, including smoking, hypertension, hyperlipidemia, coronary artery, and chronic kidney disease. Patients with symptomatic PAD have a 20% to 30% risk of stroke, myocardial infarction, or death, within 5 years [1,4,5]. Those with CLI carry the highest risk among PAD patients, with a greater risk of 5-year mortality than patients with symptomatic coronary artery disease or advanced malignancy [1]. The incidence of CLI in the Western world is estimated to be between 500 and 1,000 new cases/year/million persons [2]. In the United States, CLI is thought to affect 1% of the population over the age of 50 years, and double that rate in people over 70 years. With the aging population, it is thought that the number of people over 65 years of age will double by 2045, to 420% of the overall populous [5]. The incidence and prevalence of PAD and CLI may reach epidemic levels as the US population continues to age. Increasingly, a multidisciplinary approach to limb salvage has been employed in patients with CLI. This approach uses preventative care from primary care providers and endocrinologists to effectively manage diabetes. Podiatrists provide early management of diabetic ulcers and infection, with appropriate orthotic use and offloading techniques. Vascular surgeons and interventionalists offer prompt restitution of circulation when critical ischemia occurs, using traditional surgical bypass and a dizzying array of new endovascular techniques. Orthopedic surgeons contribute to the creation of functional amputations when necessary, and plastic surgeons provide tissue flap coverage to combat advanced tissue loss. This issue of Seminars in Vascular Surgery has been assembled to provide the vascular surgeon and interventionalist some organization to the multidisciplinary approach to limb salvage.
Specifically, we have focused on the issues most germane to the surgical and endovascular treatment of CLI, and the rationale behind these treatments. Experts in these areas have been asked to provide both best clinical evidence, as well as their personal approach to the concepts of limb salvage. Assessment of limb perfusion has always been a vexing problem for vascular surgeons, both assessing the need for revascularization and predicting adequate wound healing. Many of these technologies have not yet made it to the regular armamentarium of the surgeon, despite their potential utility. Drs. Benitez and Sumpio evaluate some of the current and emerging technologies in regional perfusion imaging modalities, such as hyperspectral imaging, fluorescent angiography, and laser Doppler. The many recent advances in limb-salvage techniques necessitate a better classification scheme to accurately predict amputation risks. Older schemes, such as the Fontaine and Rutherford classifications, failed to take into account the significant contribution of diabetic disease and the impact of extent of tissue loss and infection. Dr. Joseph Mills Sr provides an excellent synopsis of the new wound, ischemia, and foot infection (WIfI) classification recently developed by the Society for Vascular Surgery Lower Extremity Guidelines Committee. This system has exciting implications for prediction, as well as application in future clinical trials. As previously mentioned, the prognosis for patients with CLI can be dismal, especially in patients with no traditional revascularization options. This has led to the development of therapeutic angiogenesis, whereby angiogenic growth factors or stem cells can be use to foster new blood vessel growth and improve regional tissue perfusion. Drs. Ko and Bandyk summarize recent clinical trials using these biologic therapies and opine on their potential utility on treating CLI patients. The choice of the tibial target for revascularization has always been of critical importance. This has led to the development of the “angiosome hypothesis,” where the foot is divided into regions based on the feeding tibial arteries. In patients with tissue loss, a correlation is thought to exist between the location of the wound and the optimal vessel to treat. Drs. McCallum and Lane give evidence in favor of and against this hypothesis and its importance in guiding revascularization treatment. One of the most rapidly evolving arenas in the topic of CLI treatment has been in the area of infrapopliteal endovascular intervention. There has been an explosion of “disruptive technology” ranging from long-balloon angioplasty, drug-coated
2
SE
M I N A R S I N
V
A S C U L A R
balloons, bare metal and drug-coated stents, atherectomy, and retrograde tibial access. Many of these techniques have been widely employed without clear clinical benefit. Drs. Huang and Schneider give a very balanced evaluation of these emerging technologies, along with a critical assessment of their utility. Infrainguinal bypass continues to be the gold standard for the treatment of CLI. However, these techniques increasingly become a “lost art,” as technical abilities shift toward endovascular skills. For this reason, Drs. Eichler and Causey offer their “tricks and tips” for infrainguinal bypass from the University of California San Francisco group. Their stepwise approach to the bypass procedure can help to avoid the many pitfalls of the technically challenging tibial bypass. The multidisciplinary approach to limb salvage relies on the podiatrist for treatment of complex diabetic wounds and ulcers. One of their primary techniques, often lost on vascular surgeons, is the concept of loading. Drs. Miller and Armstrong provide their techniques and innovations in offloading various orthotics, including the instant total contact cast. After a successful intervention, a structured surveillance program is critical to maintaining the patency of the target vessel or graft and the durability of limb salvage. This involves clinical evaluation, vascular laboratory testing, and timely radiologic or surgical intervention. Drs. Barleben and Bandyk give their recommendations on current surveillance protocols, critique their limitations, and give insight on when reintervention is necessary. Finally, we are pleased to have an editorial from Drs. Menard and Farber, who are the principal investigators of the ongoing BEST-CLI clinical trial. This trial evaluates best endovascular versus best open surgical management of patients in the setting of CLI. It is the only National Institutes of Health sponsored randomized clinical trial to evaluate the relative effectiveness of these two modalities in CLI in order to gain a rationale approach to their respective applications.
SU
R G E R Y
27 (2014) 1–2
It is my hope that this issue of the Seminars of Vascular Surgery will provide an up-to-date education in the management of CLI for the vascular specialist. There is little doubt that this field will continue to evolve and provide new techniques for improved limb salvage and quality of life for our patients.
re fe r en ces
[1] Norgren L, Hiatt WR, Dormandy JA, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg 2007;45(Suppl. S):S5 67. [2] Marston WA, Davies SW, Armstrong B, et al. Natural history of limbs with arterial insufficiency and chronic ulceration treated without revascularization. J Vasc Surg 2006;44:108–14. [3] Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection, awareness, and treatment in primary care. JAMA 2001;286:1317–24. [4] Selvin E, Erlinger TP. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 19992000. Circulation 2004;110:738 43. [5] Projections of the Population by Age and Sex for the United States: 2010-2050 (NP2008-T12). Table 12. Washington, DC: US Census Bureau Population Division; 2008.
Guest Editor John S. Lane III, MD, FACS Professor of Vascular and Endovascular Surgery University of California San Diego Chief of Vascular Surgery La Jolla VA Hospital La Jolla, CA
0895-7967/$ - see front matter & 2015 Published by Elsevier Inc. http://dx.doi.org/10.1053/j.semvascsurg.2015.01.005
