Pedal bypass surgery after crural endovascular intervention Christian Uhl, MD, Carolin Hock, Thomas Betz, MD, Ingolf Töpel, MD, and Markus Steinbauer, MD, Regensburg, Germany Background: Many centers choose endovascular intervention as their first-line treatment for crural occlusions in patients with critical limb ischemia (Rutherford 4-6). However, unsuccessful interventions often result in major amputation. Therefore, pedal bypass surgery should be considered as an alternative first-line treatment. We reviewed the impact of a prior endovascular intervention on the outcome of our patients’ pedal bypass procedures. Methods: A retrospective analysis was conducted for all patients who had undergone pedal bypass surgery in our department from February 2008 to October 2012. We performed 75 pedal bypass operations in 71 patients (male, 54; female, 17; median age, 72 years; range, 29-90 years). In 36 of those cases, patients had undergone a prior infrapopliteal endovascular intervention (PEI group). In 39 cases, patients underwent bypass surgery as first-line treatment because their prior angiography had resulted in either unsuccessful endovascular intervention, or intervention had been deemed ‘not feasible’ (BSF group). Only autologous vein grafts were used, and no retrograde intervention was done via the pedal arteries. Endpoints of the analysis were primary and secondary patency rates, mortality, and limb salvage at 1 year postoperatively. Results: Overall primary patency at 1 year was 58.3%, and secondary patency was 61.3%. Limb salvage was 76.8% and survival was 80.4%. Graft occlusion within 30 days was 18.7%. Revision in those cases was futile and 78.6% of patients had to undergo major amputation. Primary patency at 1 year was 67.0% in PEI group vs 48.3% in BSF group (P [ .409) and secondary patency was 73.5% vs 48.6% (P [ .100). Prior endovascular intervention had no significant impact on either limb salvage (82.3% vs 71.6% at 1 year; P [ .515) or graft occlusions within 30 days (19.4% vs 17.9%; P [ .547). Survival rate at 1 year was 79.5% in PEI group and 81.3% in BSF group (P [ .765). Risk factors and indications were similar in both groups. Conclusions: Crural endovascular intervention does not seem to have a negative impact on the outcome of subsequent pedal bypass surgery. Requirements are avoiding a destruction of the target vessel and opting for timely bypass surgery whenever endovascular treatment does not achieve a sufficient perfusion for wounds to heal. Early graft occlusions are associated with a higher risk for major amputation. (J Vasc Surg 2014;59:1583-7.)
An aging population, unhealthy lifestyles, and diseases of affluence, such as diabetes, all are risk factors for peripheral arterial occlusive disease. Every 20 seconds, somewhere in the world, a leg is lost to diabetes.1,2 Atherosclerotic lesions frequently involve the crural vessels, and the prevalence of long and multilevel lesions is high.3 This process is known as critical limb ischemia (CLI), and patients frequently present with rest pain, ulcers, and gangrene (Rutherford 4-6). Their substantial comorbidities put them at risk for complications related to open bypass surgery, and morbidity and mortality rates are high. At the same time endovascular treatment (ET) techniques have improved tremendously. Therefore, many centers have adopted an endovascular-first strategy. However, the Bypass vs Angioplasty in Severe Ischaemia of the Leg From the Department of Vascular Surgery, Krankenhaus Barmherzige Brüder Regensburg. Author conflict of interest: none. Reprint requests: Christian Uhl, MD, Krankenhaus Barmherzige Brüder Regensburg, Prüfeningerstraße 86, 93049 Regensburg, Germany (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214/$36.00 Copyright Ó 2014 by the Society for Vascular Surgery. http://dx.doi.org/10.1016/j.jvs.2013.11.071
(BASIL) trial showed that patients who had undergone bypass surgery after a previously unsuccessful ET demonstrated worse amputation-free survival rates than those who had undergone primary surgical treatment without prior ET.4-6 Various studies present good patency rates for pedal bypasses.7-10 However, they all lack sufficient information on whether the underlying first-line treatment was surgery or endovascular intervention. The purpose of this study was to evaluate the outcome of pedal bypass operations in a center where ET is the first-line treatment. We assessed the impact of a prior crural angioplasty on the outcome of pedal bypass surgery in patients with CLI. Then we compared their outcome with the outcome of patients who underwent bypass surgery as their primary treatment. METHODS This is a retrospective analysis of 75 pedal bypasses between February 2008 and October 2012. During this time, we did 326 cural endovascular interventions as firstline treatment for occlusions. The indication was CLI with rest pain, ulcers, or gangrene (Rutherford 4-6). After an initial postinterventional improvement, 36 cases (prior endovascular intervention [PEI group]) went on to require pedal bypass surgery (with a median of 3 months after the intervention) due to increasing necroses. Their 1583
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Table I. Endovascular procedures
Distal popliteal artery (below knee) Tibial-fibular trunk Anterior tibial artery Posterior tibial artery Peroneal artery
Percutaneous transluminal angioplasty/ atherectomy
All
Stenosis
Long segment occlusion
5
2
3
4/1
5 12 7 11
3 1 1 2
2 11 6 9
5/0 12/0 7/0 11/0
Statistical analysis was done using SPSS 15 (SPSS Inc, Chicago, Ill). Kaplan-Meier life table method evaluated graft patency, limb salvage, and patient survival. Nonparametric Mantel-Cox log-rank test was used to compare the survival curves between the groups. The variables subjected to nonparametric testing were survival, primary patency, secondary patency, and limb salvage. c2 test and Fisher exact test were used to compare patients’ risk factors, indications, bypass characteristics, and morbidity and mortality between the PEI group and BSF group. P < .05 was deemed statistically significant. RESULTS
endovascular intervention sites and further details are shown in Table I. In 39 cases, patients underwent pedal bypass surgery first as their primary treatment without prior successful endovascular intervention (BSF group). We compared primary and secondary patency, limb salvage rates, and survival between the groups. Primary patency was defined as the period between bypass surgery and first occlusion of the bypass. Secondary patency was defined as the period between bypass surgery and second occlusion of the bypass. A limb was deemed salvageable if perfusion could be improved. Necrosis and ulcer of toes and heels were deemed salvageable, as well as multiple locations of necrosis on the foot. Gangrene of the entire foot was deemed not salvageable. Three patients underwent minor amputation before receiving any kind of revascularization treatment because there appeared to be sufficient perfusion for the amputation wounds to heal. However, this turned out not to be the case, and all three patients (PEI group, n ¼ 1; BSF group, n ¼ 2) had to undergo subsequent treatment for revascularization (with a median of 2 weeks after the minor amputation). Four patients in the PEI group underwent minor amputation after their endovascular revascularization but before their bypass operation. In 40% of all patients (PEI group, 47.2%; BSF group, 33.3%; P ¼ .161), planned minor amputations were performed in concert with their bypass operations. The demographics, risk factors, and indications are shown in Table II, and the bypass characteristics are shown in Table III. There was no retrograde intervention via the pedal arteries. Only autologous vein grafts were used, and all bypasses were controlled by angiography to exclude any technical failure. Postoperatively, 74% of patients were managed with statins, and all of patients were put on anticoagulant medication. All received the vitamin K antagonist Phenprocoumon for their anticoagulation therapy. Postoperative graft surveillance follow-ups (at discharge, and at 6, 12, 24, and 36 months postoperation) included pulse examination and duplex ultrasound imaging. Patients whose last duplex scan had been more than 6 months ago were called in for another followup in January 2013 to compile the most up-to-date data. Follow-up was complete with no patients lost during the period of our study. Wound healing and pulsatile bypass perfusion were evaluated. The bypass was considered occluded when no duplex signal could be detected.
Morbidity and mortality rates. Comparative morbidity and mortality information is shown in Table IV. The overall 30-day mortality was 4.0% (PEI group, 2.8%; BSF group, 5.1%; P ¼ .525). There were no procedure-related deaths (one myocardial infarction, one renal failure, one pulmonary failure). There were no significant differences in major complications between both groups. The overall survival rate was 80.4% at 1 year (PEI group, 79.5%; BSF group, 81.3%; P ¼ .765; Fig 1). Graft patency and limb salvage rates. Overall primary patency at 1 year was 58.3% (PEI group, 67.0%; BSF group, 48.3%; P ¼ .409; Fig 2). Overall 1-year secondary patency was 61.3%, without reaching statistical significance (PEI group, 73.5%; BSF group, 48.6%; P ¼ .100; Fig 3). There was a cumulative of 14 graft occlusions within the first 30 postoperative days (18.7%). Again, there was no significant difference between the groups (PEI group, 19.4%; BSF group, 17.9%; P ¼ .551). Limb salvage at 1 year (Fig 4) was 82.3% in PEI group and 71.6% in BSF group (P ¼ .515) with an overall limb salvage of 76.8%. Out of the 14 patients with early graft occlusions, 78.6% underwent major amputation. We did not attempt any further ETs in any of the patients with early graft occlusions before major amputation. A total of 11.1% of patients in the PEI group and 7.7% of patients in the BSF group underwent minor amputation at some point after their bypass surgery (P ¼ .454). Secondary interventions and operations. We performed five graft thrombectomies in five of the 14 patients with early graft occlusions. Unfortunately, none of them were successful, and four of them had to undergo major amputation. Furthermore, five patients successfully underwent ET for graft stenosis. One acute graft occlusion was successfully treated with lytic therapy. Lytic therapy failed in two other patients. Out of the successfully treated patients, three went on to require another intervention. Two of them received ET, and one underwent thrombectomy surgery. All of those interventions were successful. DISCUSSION The purpose of this study was to assess whether an endovascular-first approach to crural occlusions has a negative impact on the outcome of subsequent pedal bypass surgery. Our study shows that a prior endovascular intervention does not affect the outcome of pedal bypass
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Table II. Patient demographics and indications All (n ¼ 75) Median age (range), years Male Diabetes mellitus Coronary artery disease Hypertension Renal failure Smoker/ex-smoker Rest pain Ulcer/gangrene
72 56 58 32 71 35 11 5 70
PEI group (n ¼ 36)
(29-90) (74.6) (77.3) (42.7) (94.7) (46.7) (14.7) (6.7) (93.3)
71.5 26 28 15 33 17 6 1 35
(39-90) (72.2) (77.8) (41.7) (91.7) (47.2) (16.7) (2.8) (97.2)
BSF group (n ¼ 39) 71.5 30 30 17 38 18 5 4 35
P
(59-81) (76.9) (76.9) (43.6) (97.4) (46.2) (12.8) (10.3) (89.7)
.420 .575 .562 .278 .555 .442 .205 .195
BSF group (n ¼ 39), No. (%)
P
BSF, Bypass surgery first; PEI, prior endovascular intervention. Data presented as number (%) unless otherwise indicated.
Table III. Bypass characteristics All (n ¼ 75), No. (%) Level of inflow Distal superficial femoral Above-knee popliteal Below-knee popliteal Anterior tibial Posterior tibial Level of outflow Dorsalis pedis Posterior tibial Plantar arterial arch
5 4 52 11 3
PEI group (n ¼ 36), No. (%)
(6.7) (5.3) (69.3) (14.7) (4.0)
1 2 26 6 1
56 (74.7) 9 (12.0) 10 (13.3)
(2.8) (5.6) (72.2) (16.7) (2.8)
26 (72.2) 6 (16.7) 4 (11.1)
4 2 26 5 2
(10.35) (5.1) (66.7) (12.8) (5.1)
.205 .662 .220 .442 .201
30 (76.9) 3 (7.7) 6 (15.4)
.420 .227 .421
PEI group (n ¼ 36), No. (%)
BSF group (n ¼ 39), No. (%)
P
1 (2.8) 1 (2.8) 0 0 7 (19.4) 6 (16.7) 4 (11.1)
2 (5.1) 0 1 (2.6) 1 (2.6) 7 (17.9) 6 (15.4) 3 (7.7)
.525 .168 .267 .267 .551 .564 .454
BSF, Bypass surgery first; PEI, prior endovascular intervention.
Table IV. Morbidity and mortality All (n ¼ 75), No. (%) 30-day mortality Myocardial infarction Renal failure Pulmonary failure 30-day graft failure 30-day major amputation Minor amputation
3 1 1 1 14 12 7
(4.0) (1.3) (1.3) (1.3) (18.7) (16.0) (9.3)
BSF, Bypass surgery first; PEI, prior endovascular intervention.
surgery in patients with CLI. A negative predictive value of any sort could not be detected. The data demonstrated no significant difference in primary and secondary patency, limb salvage, or survival. This is where our results differ from the results of other studies. So far, the BASIL trial is the only randomized trial that compared the outcomes of bypass surgery with and without prior endovascular therapy. In the BASIL trial, amputation-free survival at 1 year was 40% for post-angioplasty bypass surgery vs 70% for primary bypass surgery.5 Nolan et al described a significantly different 1-year amputation-free survival for patients with postangioplasty bypass surgery and patients with primary bypass surgery (53% vs 76%; P ¼ .03).6 One explanation for this could be an impaired runoff caused by complications of endovascular intervention, such as embolization
or thrombosis.11 Prior studies by Joels et al indicate that endovascular interventions alter the location and level of the future bypass.11 However, when we analyzed prior angiographies, we could not detect such altered levels of in-flow or a changed distal target vessel that was caused by prior ET. There are three possible explanations for our results. First, our study only includes prior crural endovascular interventions. So we only compared the outcomes of pedal bypass surgeries with and without prior ET below the knee. Prior endovascular interventions that involved the superficial artery were not included. Second, we did not perform any retrograde endovascular interventions via the pedal arteries. We are confident that therefore the risk of embolization or thrombosis in the pedal runoff vessels was reduced to a minimum. Third, we opted for timely
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90
90
80
80
70
70
60
60
Percent
100
Percent
100
50
50
40
40
30
30
20
20
10
10
PEI – Group ----BSF – Group ____
0 0
6
PEI – Group ----BSF – Group ____
0 12
18
0
24
6
Number at risk PEI 36 BSF 39
31(SE 0.05) 29(SE 0.06)
25 (SE 0.07) 27 (SE 0.06)
22 (SE 0.07) 24 (SE 0.08)
16 (SE 0.07) 20 (SE 0.08)
Fig 1. Survival rate for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
Number at risk PEI 36 BSF 39
90
80
80
70
70
60
60
Percent
90
Percent
100
40
30
30
20
20 10
PEI – Group ----BSF – Group ____
0 0
Number at risk PEI 36 BSF 39
PEI – Group ----BSF – Group ____
0 6
12
Months 22 (SE 0.07) 19 (SE 0.08)
19 (SE 0.08) 13 (SE 0.09)
16 (SE 0.08) 10 (SE 0.09)
50
40
10
20 (SE 0.08) 16 (SE 0.09)
Fig 2. Primary patency for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
100
50
12
Months
Months
0
Number at risk PEI 36 BSF 39
6
24 (SE 0.07) 23 (SE 0.08)
12
18
24
22 (SE 0.07) 21 (SE 0.08)
18 (SE 0.08) 19 (SE 0.08)
13 (SE 0.08) 15 (SE 0.08)
Months
Fig 3. Secondary patency for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
Fig 4. Limb salvage for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
bypass surgery whenever ET did not achieve a sufficient perfusion. This strategy minimized the time that tissue was exposed to insufficient perfusion. Medical literature puts the average primary patency at 1 year somewhere between 60% and 80% and the secondary patency somewhere between 67% and 87%.7-10,12 However, there is no information on whether endovascular intervention or bypass surgery was the underlying first-line treatment.
Interestingly, patency rates are lower in more recent studies than in older ones.7,9,10,13,14 A possible explanation for this trend is the increase of ETs in the last years. Successful endovascular intervention often makes pedal bypass surgery redundant. Our study demonstrates an overall primary patency of 58.3% at 1 year and a secondary patency of 61.3%. To our knowledge, this is the first paper that presents data for pedal bypasses in the context of an endovascular-first strategy.
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Medical literature reports the 30-day graft failure rate to be between 4.2% and 11%.7-9 Panneton et al describe a 30-day graft failure of 19% in a subgroup analysis of nondiabetic patients.13 Our study yields a failure rate of 18.7% (n ¼ 14). A possible explanation for this relatively high failure rate is that we always tried a bypass procedure before major amputation. Five of those patients underwent bypass thrombectomy, which unfortunately turned out to be unsuccessful. We identified a bad runoff to be the reason for these early occlusions. All bypasses were controlled by angiography. Therefore, we were able to exclude technical failure. These results show that any reoperation for early graft failure has to be considered carefully and its indication has to be confirmed properly. This study also has its limitations. It remains unclear how a retrograde intervention via the pedal arteries would have influenced the outcome. Moreover, the monitoring time was limited, and the cohort was small. Nevertheless our study is able to give some guidance on how to best treat patients with CLI. It answers a previously unacknowledged question on the impact of an endovascular-first strategy. CONCLUSIONS An endovascular-first approach to crural occlusions does not seem to affect the outcome of subsequent pedal bypass surgery. Therefore, endovascular-first strategy seems to be justified in this special type of CLI. We were also able to show that early graft occlusions are associated with a higher risk for major amputation. AUTHOR CONTRIBUTIONS Conception and design: CU, IT, MS, TB, CH Analysis and interpretation: CU Data collection: CU, CH Writing the article: CU Critical revision of the article: CH, TB, IT, MS, CU Final approval of the article: IT, MS, CU, CH, TB Statistical analysis: CU Obtained funding: CU Overall responsibility: CU
Uhl et al 1587
REFERENCES 1. Schaper NC, Apelqvist J, Bakker K. The international consensus and practical guidelines on the management and prevention of the diabetic foot. Curr Diab Rep 2003;3:475-9. 2. Boulton AJ, Vileikyte L, Ragnarson-Tennvall G, Apelqvist J. The global burden of diabetic foot disease. Lancet 2005;366:1719-24. 3. Graziant L, Silvestro A, Bertone V, Manara E, Andreini R, Sigala A, et al. Vascular involvement in diabetic subjects with ischemic foot ulcer: a new morphologic categorization of disease severity. Eur J Vasc Endovasc Surg 2007;33:453-60. 4. Nolan BW, De Martino RR, Stone DH, Schanzer A, Goodney PP, Walsh DW, et al. Prior failed ipsilateral percutaneous endovascular intervention in patients with critical limb ischemia predicts poor outcome after lower extremity bypass. J Vasc Surg 2011;54:730-6. 5. Bradbury AW, Adam DJ, Bell J, Forbes JF, Fowkes FG, Gillespie I, et al. Bypass versus angioplasty in severe ischemia of the leg (BASIL) trial: analysis of amputation free and overall survival by treatment received. J VASC Surg 2010;51:18S-31S. 6. Böckler D, Blaurock P, Mansmann U, Schwarzbach M, Seelos R, Schuhmacher H, et al. Early surgical outcome after failed stenting for lower limb occlusion disease. J Endovasc Ther 2005;12:13-21. 7. Kalra M, Gloviczki P, Bower T, Panneton JM, Harmsen WS, Jenkins GD, et al. Limb salvage after successful pedal bypass grafting is associated with improved long-term survival. J Vasc Surg 2001;33:6-16. 8. Pomposelli FB, Kansal N, Hamdan AD, Belfield A, Sheahan M, Campbell DR, et al. A decade of experience with dorsalis pedis artery bypass: analysis of outcome in more than 1000 cases. J Vasc Surg 2003;37:307-15. 9. Huges K, Domenig CM, Hamdan AD, Schermerhorn M, Aulivola B, Blattman S, et al. Bypass to plantar and tarsal arteries: an acceptable approach to limb salvage. J Vasc Surg 2004;40:1149-57. 10. Slim H, Tiwari A, Ahmed A, Ritter JC, Zayed H, Rashid H. Distal versus ultradistal bypass grafts: amputation-free survival and patency rates in patients with critical leg ischaemia. Eur J Vasc Endovasc Surg 2011;42:83-8. 11. Joels CS, York JW, Kalbaugh CA, Cull DL, Langan EM III, Taylor SM, et al. Surgical implications of early failed endovascular intervention of the superficial femoral artery. J Vasc Surg 2008;47:562-5. 12. Brochado Neto FC, Cury MVM, Costa VS, Casella IB, Matielo MF, Nakamura ET, et al. Inframalleolar bypass grafts for limb salvage. Eur J Vasc Endovasc Surg 2010;40:747-53. 13. Panneton JM, Gloviczki P, Bower TC, Rhodes JM, Canton LG, Toomey BJ. Pedal bypass for limb salvage: impact of diabetes on longterm outcome. Ann Vasc Surg 2000;14:640-7. 14. Davidson JD, Callis T. Arterial reconstruction of vessels in the foot and ancle. Ann Surg 1993;6:699-710.
Submitted Oct 9, 2013; accepted Nov 17, 2013.
An aging population, unhealthy lifestyles, and diseases of affluence, such as diabetes, all are risk factors for peripheral arterial occlusive disease. Every 20 seconds, somewhere in the world, a leg is lost to diabetes.1,2 Atherosclerotic lesions frequently involve the crural vessels, and the prevalence of long and multilevel lesions is high.3 This process is known as critical limb ischemia (CLI), and patients frequently present with rest pain, ulcers, and gangrene (Rutherford 4-6). Their substantial comorbidities put them at risk for complications related to open bypass surgery, and morbidity and mortality rates are high. At the same time endovascular treatment (ET) techniques have improved tremendously. Therefore, many centers have adopted an endovascular-first strategy. However, the Bypass vs Angioplasty in Severe Ischaemia of the Leg From the Department of Vascular Surgery, Krankenhaus Barmherzige Brüder Regensburg. Author conflict of interest: none. Reprint requests: Christian Uhl, MD, Krankenhaus Barmherzige Brüder Regensburg, Prüfeningerstraße 86, 93049 Regensburg, Germany (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214/$36.00 Copyright Ó 2014 by the Society for Vascular Surgery. http://dx.doi.org/10.1016/j.jvs.2013.11.071
(BASIL) trial showed that patients who had undergone bypass surgery after a previously unsuccessful ET demonstrated worse amputation-free survival rates than those who had undergone primary surgical treatment without prior ET.4-6 Various studies present good patency rates for pedal bypasses.7-10 However, they all lack sufficient information on whether the underlying first-line treatment was surgery or endovascular intervention. The purpose of this study was to evaluate the outcome of pedal bypass operations in a center where ET is the first-line treatment. We assessed the impact of a prior crural angioplasty on the outcome of pedal bypass surgery in patients with CLI. Then we compared their outcome with the outcome of patients who underwent bypass surgery as their primary treatment. METHODS This is a retrospective analysis of 75 pedal bypasses between February 2008 and October 2012. During this time, we did 326 cural endovascular interventions as firstline treatment for occlusions. The indication was CLI with rest pain, ulcers, or gangrene (Rutherford 4-6). After an initial postinterventional improvement, 36 cases (prior endovascular intervention [PEI group]) went on to require pedal bypass surgery (with a median of 3 months after the intervention) due to increasing necroses. Their 1583
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1584 Uhl et al
Table I. Endovascular procedures
Distal popliteal artery (below knee) Tibial-fibular trunk Anterior tibial artery Posterior tibial artery Peroneal artery
Percutaneous transluminal angioplasty/ atherectomy
All
Stenosis
Long segment occlusion
5
2
3
4/1
5 12 7 11
3 1 1 2
2 11 6 9
5/0 12/0 7/0 11/0
Statistical analysis was done using SPSS 15 (SPSS Inc, Chicago, Ill). Kaplan-Meier life table method evaluated graft patency, limb salvage, and patient survival. Nonparametric Mantel-Cox log-rank test was used to compare the survival curves between the groups. The variables subjected to nonparametric testing were survival, primary patency, secondary patency, and limb salvage. c2 test and Fisher exact test were used to compare patients’ risk factors, indications, bypass characteristics, and morbidity and mortality between the PEI group and BSF group. P < .05 was deemed statistically significant. RESULTS
endovascular intervention sites and further details are shown in Table I. In 39 cases, patients underwent pedal bypass surgery first as their primary treatment without prior successful endovascular intervention (BSF group). We compared primary and secondary patency, limb salvage rates, and survival between the groups. Primary patency was defined as the period between bypass surgery and first occlusion of the bypass. Secondary patency was defined as the period between bypass surgery and second occlusion of the bypass. A limb was deemed salvageable if perfusion could be improved. Necrosis and ulcer of toes and heels were deemed salvageable, as well as multiple locations of necrosis on the foot. Gangrene of the entire foot was deemed not salvageable. Three patients underwent minor amputation before receiving any kind of revascularization treatment because there appeared to be sufficient perfusion for the amputation wounds to heal. However, this turned out not to be the case, and all three patients (PEI group, n ¼ 1; BSF group, n ¼ 2) had to undergo subsequent treatment for revascularization (with a median of 2 weeks after the minor amputation). Four patients in the PEI group underwent minor amputation after their endovascular revascularization but before their bypass operation. In 40% of all patients (PEI group, 47.2%; BSF group, 33.3%; P ¼ .161), planned minor amputations were performed in concert with their bypass operations. The demographics, risk factors, and indications are shown in Table II, and the bypass characteristics are shown in Table III. There was no retrograde intervention via the pedal arteries. Only autologous vein grafts were used, and all bypasses were controlled by angiography to exclude any technical failure. Postoperatively, 74% of patients were managed with statins, and all of patients were put on anticoagulant medication. All received the vitamin K antagonist Phenprocoumon for their anticoagulation therapy. Postoperative graft surveillance follow-ups (at discharge, and at 6, 12, 24, and 36 months postoperation) included pulse examination and duplex ultrasound imaging. Patients whose last duplex scan had been more than 6 months ago were called in for another followup in January 2013 to compile the most up-to-date data. Follow-up was complete with no patients lost during the period of our study. Wound healing and pulsatile bypass perfusion were evaluated. The bypass was considered occluded when no duplex signal could be detected.
Morbidity and mortality rates. Comparative morbidity and mortality information is shown in Table IV. The overall 30-day mortality was 4.0% (PEI group, 2.8%; BSF group, 5.1%; P ¼ .525). There were no procedure-related deaths (one myocardial infarction, one renal failure, one pulmonary failure). There were no significant differences in major complications between both groups. The overall survival rate was 80.4% at 1 year (PEI group, 79.5%; BSF group, 81.3%; P ¼ .765; Fig 1). Graft patency and limb salvage rates. Overall primary patency at 1 year was 58.3% (PEI group, 67.0%; BSF group, 48.3%; P ¼ .409; Fig 2). Overall 1-year secondary patency was 61.3%, without reaching statistical significance (PEI group, 73.5%; BSF group, 48.6%; P ¼ .100; Fig 3). There was a cumulative of 14 graft occlusions within the first 30 postoperative days (18.7%). Again, there was no significant difference between the groups (PEI group, 19.4%; BSF group, 17.9%; P ¼ .551). Limb salvage at 1 year (Fig 4) was 82.3% in PEI group and 71.6% in BSF group (P ¼ .515) with an overall limb salvage of 76.8%. Out of the 14 patients with early graft occlusions, 78.6% underwent major amputation. We did not attempt any further ETs in any of the patients with early graft occlusions before major amputation. A total of 11.1% of patients in the PEI group and 7.7% of patients in the BSF group underwent minor amputation at some point after their bypass surgery (P ¼ .454). Secondary interventions and operations. We performed five graft thrombectomies in five of the 14 patients with early graft occlusions. Unfortunately, none of them were successful, and four of them had to undergo major amputation. Furthermore, five patients successfully underwent ET for graft stenosis. One acute graft occlusion was successfully treated with lytic therapy. Lytic therapy failed in two other patients. Out of the successfully treated patients, three went on to require another intervention. Two of them received ET, and one underwent thrombectomy surgery. All of those interventions were successful. DISCUSSION The purpose of this study was to assess whether an endovascular-first approach to crural occlusions has a negative impact on the outcome of subsequent pedal bypass surgery. Our study shows that a prior endovascular intervention does not affect the outcome of pedal bypass
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Table II. Patient demographics and indications All (n ¼ 75) Median age (range), years Male Diabetes mellitus Coronary artery disease Hypertension Renal failure Smoker/ex-smoker Rest pain Ulcer/gangrene
72 56 58 32 71 35 11 5 70
PEI group (n ¼ 36)
(29-90) (74.6) (77.3) (42.7) (94.7) (46.7) (14.7) (6.7) (93.3)
71.5 26 28 15 33 17 6 1 35
(39-90) (72.2) (77.8) (41.7) (91.7) (47.2) (16.7) (2.8) (97.2)
BSF group (n ¼ 39) 71.5 30 30 17 38 18 5 4 35
P
(59-81) (76.9) (76.9) (43.6) (97.4) (46.2) (12.8) (10.3) (89.7)
.420 .575 .562 .278 .555 .442 .205 .195
BSF group (n ¼ 39), No. (%)
P
BSF, Bypass surgery first; PEI, prior endovascular intervention. Data presented as number (%) unless otherwise indicated.
Table III. Bypass characteristics All (n ¼ 75), No. (%) Level of inflow Distal superficial femoral Above-knee popliteal Below-knee popliteal Anterior tibial Posterior tibial Level of outflow Dorsalis pedis Posterior tibial Plantar arterial arch
5 4 52 11 3
PEI group (n ¼ 36), No. (%)
(6.7) (5.3) (69.3) (14.7) (4.0)
1 2 26 6 1
56 (74.7) 9 (12.0) 10 (13.3)
(2.8) (5.6) (72.2) (16.7) (2.8)
26 (72.2) 6 (16.7) 4 (11.1)
4 2 26 5 2
(10.35) (5.1) (66.7) (12.8) (5.1)
.205 .662 .220 .442 .201
30 (76.9) 3 (7.7) 6 (15.4)
.420 .227 .421
PEI group (n ¼ 36), No. (%)
BSF group (n ¼ 39), No. (%)
P
1 (2.8) 1 (2.8) 0 0 7 (19.4) 6 (16.7) 4 (11.1)
2 (5.1) 0 1 (2.6) 1 (2.6) 7 (17.9) 6 (15.4) 3 (7.7)
.525 .168 .267 .267 .551 .564 .454
BSF, Bypass surgery first; PEI, prior endovascular intervention.
Table IV. Morbidity and mortality All (n ¼ 75), No. (%) 30-day mortality Myocardial infarction Renal failure Pulmonary failure 30-day graft failure 30-day major amputation Minor amputation
3 1 1 1 14 12 7
(4.0) (1.3) (1.3) (1.3) (18.7) (16.0) (9.3)
BSF, Bypass surgery first; PEI, prior endovascular intervention.
surgery in patients with CLI. A negative predictive value of any sort could not be detected. The data demonstrated no significant difference in primary and secondary patency, limb salvage, or survival. This is where our results differ from the results of other studies. So far, the BASIL trial is the only randomized trial that compared the outcomes of bypass surgery with and without prior endovascular therapy. In the BASIL trial, amputation-free survival at 1 year was 40% for post-angioplasty bypass surgery vs 70% for primary bypass surgery.5 Nolan et al described a significantly different 1-year amputation-free survival for patients with postangioplasty bypass surgery and patients with primary bypass surgery (53% vs 76%; P ¼ .03).6 One explanation for this could be an impaired runoff caused by complications of endovascular intervention, such as embolization
or thrombosis.11 Prior studies by Joels et al indicate that endovascular interventions alter the location and level of the future bypass.11 However, when we analyzed prior angiographies, we could not detect such altered levels of in-flow or a changed distal target vessel that was caused by prior ET. There are three possible explanations for our results. First, our study only includes prior crural endovascular interventions. So we only compared the outcomes of pedal bypass surgeries with and without prior ET below the knee. Prior endovascular interventions that involved the superficial artery were not included. Second, we did not perform any retrograde endovascular interventions via the pedal arteries. We are confident that therefore the risk of embolization or thrombosis in the pedal runoff vessels was reduced to a minimum. Third, we opted for timely
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1586 Uhl et al
90
90
80
80
70
70
60
60
Percent
100
Percent
100
50
50
40
40
30
30
20
20
10
10
PEI – Group ----BSF – Group ____
0 0
6
PEI – Group ----BSF – Group ____
0 12
18
0
24
6
Number at risk PEI 36 BSF 39
31(SE 0.05) 29(SE 0.06)
25 (SE 0.07) 27 (SE 0.06)
22 (SE 0.07) 24 (SE 0.08)
16 (SE 0.07) 20 (SE 0.08)
Fig 1. Survival rate for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
Number at risk PEI 36 BSF 39
90
80
80
70
70
60
60
Percent
90
Percent
100
40
30
30
20
20 10
PEI – Group ----BSF – Group ____
0 0
Number at risk PEI 36 BSF 39
PEI – Group ----BSF – Group ____
0 6
12
Months 22 (SE 0.07) 19 (SE 0.08)
19 (SE 0.08) 13 (SE 0.09)
16 (SE 0.08) 10 (SE 0.09)
50
40
10
20 (SE 0.08) 16 (SE 0.09)
Fig 2. Primary patency for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
100
50
12
Months
Months
0
Number at risk PEI 36 BSF 39
6
24 (SE 0.07) 23 (SE 0.08)
12
18
24
22 (SE 0.07) 21 (SE 0.08)
18 (SE 0.08) 19 (SE 0.08)
13 (SE 0.08) 15 (SE 0.08)
Months
Fig 3. Secondary patency for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
Fig 4. Limb salvage for prior endovascular intervention (PEI) group and bypass surgery first (BSF) group. SE, Standard error.
bypass surgery whenever ET did not achieve a sufficient perfusion. This strategy minimized the time that tissue was exposed to insufficient perfusion. Medical literature puts the average primary patency at 1 year somewhere between 60% and 80% and the secondary patency somewhere between 67% and 87%.7-10,12 However, there is no information on whether endovascular intervention or bypass surgery was the underlying first-line treatment.
Interestingly, patency rates are lower in more recent studies than in older ones.7,9,10,13,14 A possible explanation for this trend is the increase of ETs in the last years. Successful endovascular intervention often makes pedal bypass surgery redundant. Our study demonstrates an overall primary patency of 58.3% at 1 year and a secondary patency of 61.3%. To our knowledge, this is the first paper that presents data for pedal bypasses in the context of an endovascular-first strategy.
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Medical literature reports the 30-day graft failure rate to be between 4.2% and 11%.7-9 Panneton et al describe a 30-day graft failure of 19% in a subgroup analysis of nondiabetic patients.13 Our study yields a failure rate of 18.7% (n ¼ 14). A possible explanation for this relatively high failure rate is that we always tried a bypass procedure before major amputation. Five of those patients underwent bypass thrombectomy, which unfortunately turned out to be unsuccessful. We identified a bad runoff to be the reason for these early occlusions. All bypasses were controlled by angiography. Therefore, we were able to exclude technical failure. These results show that any reoperation for early graft failure has to be considered carefully and its indication has to be confirmed properly. This study also has its limitations. It remains unclear how a retrograde intervention via the pedal arteries would have influenced the outcome. Moreover, the monitoring time was limited, and the cohort was small. Nevertheless our study is able to give some guidance on how to best treat patients with CLI. It answers a previously unacknowledged question on the impact of an endovascular-first strategy. CONCLUSIONS An endovascular-first approach to crural occlusions does not seem to affect the outcome of subsequent pedal bypass surgery. Therefore, endovascular-first strategy seems to be justified in this special type of CLI. We were also able to show that early graft occlusions are associated with a higher risk for major amputation. AUTHOR CONTRIBUTIONS Conception and design: CU, IT, MS, TB, CH Analysis and interpretation: CU Data collection: CU, CH Writing the article: CU Critical revision of the article: CH, TB, IT, MS, CU Final approval of the article: IT, MS, CU, CH, TB Statistical analysis: CU Obtained funding: CU Overall responsibility: CU
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Submitted Oct 9, 2013; accepted Nov 17, 2013.
