482
J ENDOVASC THER 2014;21:482–484
^ COMMENTARY
———————————————————————————————
^
Subintimal Angioplasty and Stenting of Chronic Total Femoropopliteal Occlusions: Is Distal Protection Needed? Nicolas W. Shammas, MD, MS Midwest Cardiovascular Research Foundation, Davenport, Iowa, USA.
Distal embolization (DE) during lower extremity arterial interventions is a frequent occurrence with several predictors, including severe calcified disease, total occlusions, long lesions, thrombotic lesions, and the use of atherectomy devices.1–8 The majority of DE are generally asymptomatic and do not require further management, but it remains unknown whether these ‘‘microparticulates’’ are associated with long-term adverse outcomes. On the other hand, DEs large enough to obstruct outflow vessels and impair distal circulation occur in 2% to 3% of infrainguinal arterial interventions.8 They generally lead to additional pharmacological and mechanical interventions and are associated with longer procedure time, higher contrast use, more radiation exposure, 9 and longer hospital stay.10 In this issue of the JEVT, Spiliopoulos et al.11 report that subintimal angioplasty (SIA) with and/or without stenting carries no distal macroembolization potential based on their prospective study. Their observation is in contrast to reported data in treating femoropopliteal chronic total occlusions (CTO) by other operators using different techniques.3,4,6,7 Excluding patients with acute and subacute occlusions and those with intraluminal crossing, the Spider FX filter (Covidien, Mansfield, MA, USA) was used in 40 patients with femoropopliteal CTO following subintimal recanalization and treatment of
the lesions with either angioplasty alone (n¼14) or angioplasty and stenting (n¼26). None of the patients had visible particulate debris in the filters, and no angiographically visible DE occurred. All lesions, however, had evidence of microembolization (less than 100 lm), mostly debris from atherosclerotic plaque and a small amount of fresh thrombus. All patients were treated with clopidogrel and aspirin for 5 days prior to the procedure but a fixed dose of unfractionated heparin was used (5000 units) intraprocedurally, and no activated clotting times (ACT) were reported. This study raises several questions. Does the lack of clinically important DE with SIA make this approach more appealing as a primary modality in treating femoropopliteal CTO? Is there tangible cost savings by not using embolic filters or an embolic capture balloon in treating these lesions? Can these results be reproducible in a larger cohort of patients and among different operators? SIA has been shown to be an effective method to treat femoropopliteal CTO, with good acute and short-term results, including improvement in disabling claudication and a reduced rate of amputation in limb ischemia patients.12–14 However, SIA, particularly in long total occlusions, diabetics, and in patients with critical limb ischemia, has a reduced primary patency rate at 1 year ranging from 45% to 62%.12–14 Furthermore, a routine subintimal approach in treating
Invited commentaries published in the Journal of Endovascular Therapy reflect the opinions of the author(s) and do not necessarily represent the views of the Journal or the INTERNATIONAL SOCIETY OF ENDOVASCULAR SPECIALISTS. Nicolas Shammas receives relevant research and educational grants from Covidien and Abbott. Full disclosure available at www.mcrfmd.com Corresponding author: Nicolas W. Shammas, MS, MD, Research Director, Midwest Cardiovascular Research Foundation, 1236 East Rusholme, Suite 300, Davenport, IA 52803-2468 USA. E-mail: [email protected] Q 2014 INTERNATIONAL SOCIETY
OF
ENDOVASCULAR SPECIALISTS
doi:10.1583/14-4703C.1
Available at www.jevt.org
J ENDOVASC THER 2014;21:482–484
femoropopliteal CTO generally indicates that debulking methods with atherectomy would be more likely eliminated as an option to treat these lesions. Although atherectomy has not been shown to reduce target lesion revascularization compared to plain old balloon angioplasty in de novo femoropopliteal lesions,5 it has the advantage of reducing stenting and dissection rates. Finally, embolic filter protection or embolic capture balloons are user-friendly and safe to use as demonstrated by many operators and adds very little to the time of the procedure. Both the SpiderFX filter and the Proteus embolic protection balloon (Angioslide Inc, Wheat Ridge, CO, USA) have been approved as embolic protection devices in lower extremity interventions. Given the low long-term patency with SIA or stenting, ease of use of embolic protection devices, and the elimination of atherectomy as a viable option with a subintimal approach, the routine application of SIA to treat femoropopliteal CTO despite a reduction in DE is less likely to become a first line treatment for these lesions. Nevertheless, this technique seems to be a viable alternative to bypass surgery for treating long femoropopliteal CTOs in certain patient subgroups, particularly those who are not good surgical candidates or who refuse surgery or in those who cannot be treated using an intraluminal approach. The number of patients (n¼40) in the Spiliopoulos study is small, and therefore their findings need to be validated in a larger prospective cohort. Published data indicate that DE can still occur when treating femoropopliteal CTO in 1.2% to 3% of lesions and may require further pharmacological or mechanical treatment.15,16 Tatli et al.15 reported on 72 patients with femoropopliteal CTO lesions treated with SIA and stenting. DEinduced limb ischemia occurred in 3% of their patients and was treated with fibrinolysis. Also, Hong et al.16 reported 1.2% DE in the treatment of 161 limbs with femoropopliteal CTO. The true incidence of DE with SIA is therefore unknown and its predictors are unclear. Although, theoretically, a subintimal approach can shield the plaque by the intimal/ subintimal layer created by the wire in the subintimal dissection plane, plaque shifting
COMMENTARY Shammas
483
can still occur after balloon inflation. Also, the authors pointed to the presence of a heightened platelet and thrombin activity with subintimal wire crossing,17 so maintaining intraprocedural optimal anticoagulation is important to prevent in situ thrombus formation and DE. Unfractionated heparin has unpredictable anticoagulation,18 and it is unclear whether fresh thrombotic DE captured in the filter could be attributed to a fluctuating lower level of anticoagulation. Although no optimal ACT has been defined during percutaneous peripheral interventions to prevent thrombus formation, a therapeutic target range of 220 to 240 seconds is currently commonly used. Spiliopoulos et al.11 included more TASC (TransAtlantic Inter-Society Consensus) A and B lesions (over 60%), so their data should be cautiously extrapolated to TASC C and D lesions. Furthermore, the definitions of macroembolization (.100 lm) and microembolization (,100 lm) appear arbitrary and may have no practical clinical application. At this time, it is unknown whether microembolization or macroembolization small enough to not angiographically obstruct a tibial or peroneal vessel would result in an acute or long-term serious adverse event. Finally, the Spider filter can allow particulates up to 200 lm to go through its mesh; thus, ‘‘macroembolization’’ as defined by the authors could have occurred undetected beyond the filter. Despite the shortcomings of this study, I believe it has significant value in understanding the histopathology of embolic particulates generated during the treatment of femoropopliteal CTO using SIA and the role of embolic filter protection in treating these lesions. Whether embolic filter protection will eventually be needed or cost-effective in treating femoropopliteal CTO using SIA will have to await larger prospective registries and/or data from randomized trials.
REFERENCES 1. Siablis D, Karnabatidis D, Katsanos K, et al. Outflow protection filters during percutaneous recanalization of lower extremities’ arterial occlusions: a pilot study. Eur J Radiol. 2005; 55:243–249.
484
COMMENTARY Shammas
2. Suri R, Wholey MH, Postoak D, et al. Distal embolic protection during femoropopliteal atherectomy. Catheter Cardiovasc Interv. 2006;67: 417–422. 3. Karnabatidis D, Katsanos K, Kagadis GC, et al. Distal embolism during percutaneous revascularization of infra-aortic arterial occlusive disease: an underestimated phenomenon. J Endovasc Ther. 2006;13:269–280. 4. Shammas NW, Dippel EJ, Coiner D, et al. Preventing lower extremity distal embolization using embolic filter protection: results of the PROTECT registry. J Endovasc Ther. 2008;15: 270–276. 5. Shammas NW, Coiner D, Shammas GA, et al. Percutaneous lower-extremity arterial interventions with primary balloon angioplasty versus Silverhawk atherectomy and adjunctive balloon angioplasty: randomized trial. J Vasc Interv Radiol. 2011;22:1223–1228. 6. Shammas NW, Coiner D, Shammas GA, et al. Distal embolic event protection using excimer laser ablation in peripheral vascular interventions: results of the DEEP EMBOLI registry. J Endovasc Ther. 2009;16:197–202. 7. Lam RC, Shah S, Faries PL, et al. Incidence and clinical significance of distal embolization during percutaneous interventions involving the superficial femoral artery. J Vasc Surg. 2007;46: 1155–1159. 8. Shammas NW, Shammas GA, Dippel EJ, et al. Predictors of distal embolization in peripheral percutaneous interventions: a report from a large peripheral vascular registry. J Invasive Cardiol. 2009;21:628–631. 9. Shammas NW, Shammas GA, Dippel EJ, et al. Intraprocedural outcomes following distal lower extremity embolization in patients undergoing peripheral percutaneous interventions. Vascular Disease Management. 2009;6:58–61 10. Dippel EJ, Parikh N, Wallace KL. Use of SpiderFX embolic protection device vs. distal
J ENDOVASC THER 2014;21:482–484
11.
12.
13.
14.
15.
16.
17.
18.
embolic event: hospital length of stay, operating room time, costs and mortality [abstract]. J Am Coll Cardiol. 2013;62(18_S1):B161. Spiliopoulos S, Theodosiadou V, Koukounas V, et al. Distal macro- and microembolization during subintimal recanalization of femoropopliteal chronic total occlusions. J Endovasc Ther. 2014;21:474–481. Scott EC, Biuckians A, Light RE, et al. Subintimal angioplasty for the treatment of claudication and critical limb ischemia: 3-year results. J Vasc Surg. 2007;46:959–964. Flrenes T, Bay D, Sandbaek G, et al. Subintimal angioplasty in the treatment of patients with intermittent claudication: long term results. Eur J Vasc Endovasc Surg. 2004;28:645–650. Met R, Van Lienden KP, Koelemay MJ, et al. Subintimal angioplasty for peripheral arterial occlusive disease: a systematic review. Cardiovasc Intervent Radiol. 2008;31:687–697. Tatli E, Buturak A, Kayapınar O, et al. Subintimal angioplasty and stenting for chronic total femoropopliteal artery occlusions: early and mid-term outcomes. Cardiol J. 2014 May 20 [Epub ahead of print]. Hong SJ, Ko YG, Kim JS, et al. Midterm outcomes of subintimal angioplasty supported by primary proximal stenting for chronic total occlusion of the superficial femoral artery. J Endovasc Ther. 2013;20:782–791. Jenssen EK, Brosstad F, Pedersen T, et al. Thrombin generation and platelet activation related to subintimal percutaneous transluminal angioplasty. Scand J Clin Lab Invest. 2012; 72:23–28. Shammas NW, Lemke JH, Dippel EJ, et al. Inhospital complications of peripheral vascular interventions using unfractionated heparin as the primary anticoagulant. J Invasive Cardiol. 2003;15:242–246.
J ENDOVASC THER 2014;21:482–484
^ COMMENTARY
———————————————————————————————
^
Subintimal Angioplasty and Stenting of Chronic Total Femoropopliteal Occlusions: Is Distal Protection Needed? Nicolas W. Shammas, MD, MS Midwest Cardiovascular Research Foundation, Davenport, Iowa, USA.
Distal embolization (DE) during lower extremity arterial interventions is a frequent occurrence with several predictors, including severe calcified disease, total occlusions, long lesions, thrombotic lesions, and the use of atherectomy devices.1–8 The majority of DE are generally asymptomatic and do not require further management, but it remains unknown whether these ‘‘microparticulates’’ are associated with long-term adverse outcomes. On the other hand, DEs large enough to obstruct outflow vessels and impair distal circulation occur in 2% to 3% of infrainguinal arterial interventions.8 They generally lead to additional pharmacological and mechanical interventions and are associated with longer procedure time, higher contrast use, more radiation exposure, 9 and longer hospital stay.10 In this issue of the JEVT, Spiliopoulos et al.11 report that subintimal angioplasty (SIA) with and/or without stenting carries no distal macroembolization potential based on their prospective study. Their observation is in contrast to reported data in treating femoropopliteal chronic total occlusions (CTO) by other operators using different techniques.3,4,6,7 Excluding patients with acute and subacute occlusions and those with intraluminal crossing, the Spider FX filter (Covidien, Mansfield, MA, USA) was used in 40 patients with femoropopliteal CTO following subintimal recanalization and treatment of
the lesions with either angioplasty alone (n¼14) or angioplasty and stenting (n¼26). None of the patients had visible particulate debris in the filters, and no angiographically visible DE occurred. All lesions, however, had evidence of microembolization (less than 100 lm), mostly debris from atherosclerotic plaque and a small amount of fresh thrombus. All patients were treated with clopidogrel and aspirin for 5 days prior to the procedure but a fixed dose of unfractionated heparin was used (5000 units) intraprocedurally, and no activated clotting times (ACT) were reported. This study raises several questions. Does the lack of clinically important DE with SIA make this approach more appealing as a primary modality in treating femoropopliteal CTO? Is there tangible cost savings by not using embolic filters or an embolic capture balloon in treating these lesions? Can these results be reproducible in a larger cohort of patients and among different operators? SIA has been shown to be an effective method to treat femoropopliteal CTO, with good acute and short-term results, including improvement in disabling claudication and a reduced rate of amputation in limb ischemia patients.12–14 However, SIA, particularly in long total occlusions, diabetics, and in patients with critical limb ischemia, has a reduced primary patency rate at 1 year ranging from 45% to 62%.12–14 Furthermore, a routine subintimal approach in treating
Invited commentaries published in the Journal of Endovascular Therapy reflect the opinions of the author(s) and do not necessarily represent the views of the Journal or the INTERNATIONAL SOCIETY OF ENDOVASCULAR SPECIALISTS. Nicolas Shammas receives relevant research and educational grants from Covidien and Abbott. Full disclosure available at www.mcrfmd.com Corresponding author: Nicolas W. Shammas, MS, MD, Research Director, Midwest Cardiovascular Research Foundation, 1236 East Rusholme, Suite 300, Davenport, IA 52803-2468 USA. E-mail: [email protected] Q 2014 INTERNATIONAL SOCIETY
OF
ENDOVASCULAR SPECIALISTS
doi:10.1583/14-4703C.1
Available at www.jevt.org
J ENDOVASC THER 2014;21:482–484
femoropopliteal CTO generally indicates that debulking methods with atherectomy would be more likely eliminated as an option to treat these lesions. Although atherectomy has not been shown to reduce target lesion revascularization compared to plain old balloon angioplasty in de novo femoropopliteal lesions,5 it has the advantage of reducing stenting and dissection rates. Finally, embolic filter protection or embolic capture balloons are user-friendly and safe to use as demonstrated by many operators and adds very little to the time of the procedure. Both the SpiderFX filter and the Proteus embolic protection balloon (Angioslide Inc, Wheat Ridge, CO, USA) have been approved as embolic protection devices in lower extremity interventions. Given the low long-term patency with SIA or stenting, ease of use of embolic protection devices, and the elimination of atherectomy as a viable option with a subintimal approach, the routine application of SIA to treat femoropopliteal CTO despite a reduction in DE is less likely to become a first line treatment for these lesions. Nevertheless, this technique seems to be a viable alternative to bypass surgery for treating long femoropopliteal CTOs in certain patient subgroups, particularly those who are not good surgical candidates or who refuse surgery or in those who cannot be treated using an intraluminal approach. The number of patients (n¼40) in the Spiliopoulos study is small, and therefore their findings need to be validated in a larger prospective cohort. Published data indicate that DE can still occur when treating femoropopliteal CTO in 1.2% to 3% of lesions and may require further pharmacological or mechanical treatment.15,16 Tatli et al.15 reported on 72 patients with femoropopliteal CTO lesions treated with SIA and stenting. DEinduced limb ischemia occurred in 3% of their patients and was treated with fibrinolysis. Also, Hong et al.16 reported 1.2% DE in the treatment of 161 limbs with femoropopliteal CTO. The true incidence of DE with SIA is therefore unknown and its predictors are unclear. Although, theoretically, a subintimal approach can shield the plaque by the intimal/ subintimal layer created by the wire in the subintimal dissection plane, plaque shifting
COMMENTARY Shammas
483
can still occur after balloon inflation. Also, the authors pointed to the presence of a heightened platelet and thrombin activity with subintimal wire crossing,17 so maintaining intraprocedural optimal anticoagulation is important to prevent in situ thrombus formation and DE. Unfractionated heparin has unpredictable anticoagulation,18 and it is unclear whether fresh thrombotic DE captured in the filter could be attributed to a fluctuating lower level of anticoagulation. Although no optimal ACT has been defined during percutaneous peripheral interventions to prevent thrombus formation, a therapeutic target range of 220 to 240 seconds is currently commonly used. Spiliopoulos et al.11 included more TASC (TransAtlantic Inter-Society Consensus) A and B lesions (over 60%), so their data should be cautiously extrapolated to TASC C and D lesions. Furthermore, the definitions of macroembolization (.100 lm) and microembolization (,100 lm) appear arbitrary and may have no practical clinical application. At this time, it is unknown whether microembolization or macroembolization small enough to not angiographically obstruct a tibial or peroneal vessel would result in an acute or long-term serious adverse event. Finally, the Spider filter can allow particulates up to 200 lm to go through its mesh; thus, ‘‘macroembolization’’ as defined by the authors could have occurred undetected beyond the filter. Despite the shortcomings of this study, I believe it has significant value in understanding the histopathology of embolic particulates generated during the treatment of femoropopliteal CTO using SIA and the role of embolic filter protection in treating these lesions. Whether embolic filter protection will eventually be needed or cost-effective in treating femoropopliteal CTO using SIA will have to await larger prospective registries and/or data from randomized trials.
REFERENCES 1. Siablis D, Karnabatidis D, Katsanos K, et al. Outflow protection filters during percutaneous recanalization of lower extremities’ arterial occlusions: a pilot study. Eur J Radiol. 2005; 55:243–249.
484
COMMENTARY Shammas
2. Suri R, Wholey MH, Postoak D, et al. Distal embolic protection during femoropopliteal atherectomy. Catheter Cardiovasc Interv. 2006;67: 417–422. 3. Karnabatidis D, Katsanos K, Kagadis GC, et al. Distal embolism during percutaneous revascularization of infra-aortic arterial occlusive disease: an underestimated phenomenon. J Endovasc Ther. 2006;13:269–280. 4. Shammas NW, Dippel EJ, Coiner D, et al. Preventing lower extremity distal embolization using embolic filter protection: results of the PROTECT registry. J Endovasc Ther. 2008;15: 270–276. 5. Shammas NW, Coiner D, Shammas GA, et al. Percutaneous lower-extremity arterial interventions with primary balloon angioplasty versus Silverhawk atherectomy and adjunctive balloon angioplasty: randomized trial. J Vasc Interv Radiol. 2011;22:1223–1228. 6. Shammas NW, Coiner D, Shammas GA, et al. Distal embolic event protection using excimer laser ablation in peripheral vascular interventions: results of the DEEP EMBOLI registry. J Endovasc Ther. 2009;16:197–202. 7. Lam RC, Shah S, Faries PL, et al. Incidence and clinical significance of distal embolization during percutaneous interventions involving the superficial femoral artery. J Vasc Surg. 2007;46: 1155–1159. 8. Shammas NW, Shammas GA, Dippel EJ, et al. Predictors of distal embolization in peripheral percutaneous interventions: a report from a large peripheral vascular registry. J Invasive Cardiol. 2009;21:628–631. 9. Shammas NW, Shammas GA, Dippel EJ, et al. Intraprocedural outcomes following distal lower extremity embolization in patients undergoing peripheral percutaneous interventions. Vascular Disease Management. 2009;6:58–61 10. Dippel EJ, Parikh N, Wallace KL. Use of SpiderFX embolic protection device vs. distal
J ENDOVASC THER 2014;21:482–484
11.
12.
13.
14.
15.
16.
17.
18.
embolic event: hospital length of stay, operating room time, costs and mortality [abstract]. J Am Coll Cardiol. 2013;62(18_S1):B161. Spiliopoulos S, Theodosiadou V, Koukounas V, et al. Distal macro- and microembolization during subintimal recanalization of femoropopliteal chronic total occlusions. J Endovasc Ther. 2014;21:474–481. Scott EC, Biuckians A, Light RE, et al. Subintimal angioplasty for the treatment of claudication and critical limb ischemia: 3-year results. J Vasc Surg. 2007;46:959–964. Flrenes T, Bay D, Sandbaek G, et al. Subintimal angioplasty in the treatment of patients with intermittent claudication: long term results. Eur J Vasc Endovasc Surg. 2004;28:645–650. Met R, Van Lienden KP, Koelemay MJ, et al. Subintimal angioplasty for peripheral arterial occlusive disease: a systematic review. Cardiovasc Intervent Radiol. 2008;31:687–697. Tatli E, Buturak A, Kayapınar O, et al. Subintimal angioplasty and stenting for chronic total femoropopliteal artery occlusions: early and mid-term outcomes. Cardiol J. 2014 May 20 [Epub ahead of print]. Hong SJ, Ko YG, Kim JS, et al. Midterm outcomes of subintimal angioplasty supported by primary proximal stenting for chronic total occlusion of the superficial femoral artery. J Endovasc Ther. 2013;20:782–791. Jenssen EK, Brosstad F, Pedersen T, et al. Thrombin generation and platelet activation related to subintimal percutaneous transluminal angioplasty. Scand J Clin Lab Invest. 2012; 72:23–28. Shammas NW, Lemke JH, Dippel EJ, et al. Inhospital complications of peripheral vascular interventions using unfractionated heparin as the primary anticoagulant. J Invasive Cardiol. 2003;15:242–246.
