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Tibiodistal vein bypass in critical limb ischemia and its role after unsuccessful tibial angioplasty
From the Vascular and Endovascular Surgery Society
Tibiodistal vein bypass in critical limb ischemia and its role after unsuccessful tibial angioplasty Florian K. Enzmann, MD,a Sebastian K. Eder, MD,a Thomas Aschacher, MD,b Manuela Aspalter, MD,a Patrick Nierlich, MD, PhD,a Klaus Linni, MD,a and Thomas J. Hölzenbein, MD,a Salzburg and Vienna, Austria
ABSTRACT Objective: Technical progress in angioplasty expanded its application to very distal arterial lesions of the lower extremity. In cases of unsuccessful angioplasty tibiodistal bypass surgery may be required for limb salvage. We investigated the long-term outcome of this technique in patients with critical limb ischemia. The purpose of this study was to evaluate whether tibiodistal bypasses done after unsuccessful tibial angioplasty had inferior patency, limb salvage, or survival rates compared with primary tibiodistal bypasses. Methods: This single-center, retrospective data analysis included all distal bypass procedures originating from a tibial artery. Primary study end points were primary patency, secondary patency, and limb salvage. Secondary end points included survival, wound healing, and systemic and local complications. Society for Vascular Surgery reporting standards were applied. Results: There were 61 tibiodistal vein bypasses for critical limb ischemia performed in 23 years. Indications for tibiodistal bypass was Rutherford category 5 in 41 cases (67%) and category 6 in 20 cases (33%). Procedures were allocated to group A (primary bypass; n ¼ 28) and group B (bypass after unsuccessful tibial angioplasty; n ¼ 33). Primary patency was 55% versus 53% at 1 year and 47% versus 44% at 3 years (P ¼ .58). Secondary patency was 59% versus 64% at 1 year and 52% versus 55% at 3 years (P ¼ .36). Limb salvage was 96% versus 90% at 1 year and 91% versus 85% at 3 years (P ¼ .44). Overall survival rates were 91% versus 97% at 1 year and 85% versus 92% at 3 years (P ¼ .76). The median follow-up was 4.0 years in group A and 4.9 years in group B. In multivariate analyses for loss of primary patency and limb loss, no significant predictors could be identified. Conclusions: This study showed that tibiodistal vein bypass is a feasible, efficient, and safe technique in patients with critical limb ischemia. It provides acceptable primary and secondary patency rates to prevent major amputation and ensure survival. Previous unsuccessful tibial angioplasty had no significant impact on tibiodistal vein bypass outcome. This technique should be part of the armamentarium of vascular surgeons. (J Vasc Surg 2018;67:1191-8.)
Since the 1990s, tibial percutaneous transluminal angioplasty (PTA) is increasingly advocated and considered as feasible, safe, and effective in critical limb ischemia (CLI)1 with similar outcomes compared with bypass surgery.2,3 In contrast, there is growing evidence of inferior outcome in patients undergoing bypass surgery after failed infrainguinal PTA4-6 and poorer wound healing after infrapopliteal PTA compared with bypass surgery.7,8
From the Department of Vascular and Endovascular Surgery, Paracelsus Medical University Salzburg, Salzburga; and the Department of Surgery, Cardiac Surgery, Medical University of Vienna, Vienna.b Author conflict of interest: none. Presented at the 2017 Annual Winter Meeting of the Vascular and Endovascular Surgery Society, Steamboat Springs, Colo, February 2-5, 2017. Correspondence: Florian K. Enzmann, MD, Department of Vascular and Endovascular Surgery, Paracelsus Medical University Salzburg, Müllner Hauptstrasse 48, Salzburg A-5020, Austria (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 Copyright Ó 2017 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2017.07.127
Some authors prefer an endovascular first approach,9 whereas the American College of Cardiology Foundation/American Heart Association stated that a bypass surgery first approach is reasonable in CLI patients with a life expectancy of more than 2 years and useable vein grafts.10 The decision making process, whether an unconditional endovascular first strategy for isolated tibial lesions is sustainable in contrast to primary distal bypass surgery, was particularly interesting for us. Distal bypass procedures usually originated from the common femoral artery until Veith et al11 introduced the short bypass principle in 1981. Superficial femoral and popliteal artery were shown to be suitable inflow sites for distal bypasses.11 The advantages of the resulting shorter bypasses are short vein grafts are reported to have better patency,12 and it is possible to limit the extend of surgical dissection and reduce operative time.13 Additionally, bypass length can be kept as short as possible in cases of limited vein graft owing to prior coronary artery bypass procedure, varicose vein treatment or previous peripheral bypass surgery.13 In 1982, Danza14 was the first to report 10 distal bypasses originating from tibial arteries as part of a larger case series. 1191
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There was only one dedicated report 23 years ago, describing 42 tibiodistal bypasses by the Veith group with primary patency and limb salvage rates in patients with CLI comparable with those of femorotibial bypasses.13 In the era of endovascular first procedures for isolated tibial lesions tibiodistal bypass may deserve a renaissance especially as a bail-out technique after unsuccessful PTA. The aim of this study was to evaluate whether the technique of tibiodistal bypass after unsuccessful tibial PTA had inferior patency, limb salvage, or survival rates compared with primary tibiodistal bypass in patients with CLI.
METHODS We performed a single-center, retrospective data analysis of all distal bypass procedures originating from a tibial artery (anterior tibial artery, posterior tibial artery, peroneal artery) performed from 1995 to 2017. Patients undergoing a primary bypass were categorized as group A and patients undergoing tibiodistal bypass as a bailout procedure after unsuccessful tibial PTA as group B (Fig 1). The institutional review board approved the study and waived a requirement for informed patient consent because of its retrospective design. All pedal bypasses were performed in an academic tertiary referral center. Distal redo bypass procedures were included.15 Bypasses originating from the popliteal or more proximal arteries as well as grafts performed as distal extensions from previous bypasses were excluded. The collected data included patient characteristics, technical data of the bypass procedure, local and systemic complications, reinterventions, and follow-up. Indication. Tibiodistal bypass surgery was performed in patients with tissue loss in all cases, classified according to the Rutherford categories 5 or 6.16 Management included revascularization before minor amputation and debridement. There were no significant proximal inflow lesions at the time of tibiodistal bypass procedure. Angioplasty. If PTA of the tibial arteries was attempted before the bypass procedure, it was either impossible to cross the lesion to the patent pedal artery, occluded soon after the intervention, or proved to be insufficient to heal the lesions and provided no clinical improvement. Operative technique and follow-up. Operative technique included standard tibial and pedal artery exposure, systemic heparinization, and completion digital subtraction angiography. We performed all bypasses with autologous vein grafts. The postoperative antithrombotic medication was at the discretion of the surgeon and was individually adapted to the comorbidities of patients (eg, atrial fibrillation, coronary artery disease).
ARTICLE HIGHLIGHTS d
d
d
Type of Research: Single-center retrospective cohort study Take Home Message: In a group of 61 tibiodistal bypasses performed for patients with critical limb ischemia who underwent unsuccessful angioplasty before bypass had 3-year primary and secondary patencies and limb salvage of 44%, 55%, and 85%, respectively, not significantly different from those who had no previous angioplasty (47%, 52%, and 91%, respectively). Recommendation: This study suggests that unsuccessful tibial angioplasty does not diminish the very acceptable patency rates or limb salvage of tibiodistal bypasses performed for critical limb ischemia.
Follow-up started at the day after bypass procedure and patients were usually examined at our outpatient clinic after 1, 3, 6, and 12 months, followed by visits at yearly intervals. This included a clinical examination, hand-held doppler ultrasound and measurements of the ankle-brachial index. In cases of clinical or anklebrachial index deterioration, duplex sonography of the bypass graft was performed. Definitions and study end points. According to the criteria established by the Society of Vascular Surgery, primary patency was defined as freedom from reintervention to maintain bypass patency. Secondary patency included all interventions to restore patency after occlusion.16 The primary study end points were primary patency, secondary patency, and limb salvage. Secondary end points included survival, wound healing, systemic complications (myocardial infarction, stroke, renal failure, blood transfusion, sepsis), and local complications like unplanned, late minor amputation (after >3 months) and surgical site infection (SSI), which was categorized as superficial incisional SSI or deep incisional SSI.17 Statistical analysis. To evaluate differences between the groups, demographics, cardiovascular risk factors, preoperative Rutherford category,16 and bypass characteristics were compared. All normally distributed continuous variables are expressed as means and standard deviations and were compared using the Student t test. Categorical variables are reported as frequencies and analyzed using the c2 test. The Kaplan-Meier method was used to estimate primary patency, secondary patency, limb salvage, and overall survival for primary bypass and previous unsuccessful PTA subjects, respectively. Group differences were assessed with log-rank tests. The median followup time was assessed using the reverse Kaplan-Meier
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Fig 1. Tibiodistal vein bypass after unsuccessful percutaneous transluminal angioplasty (PTA) of the distal anterior tibial artery (A), performed with reversed lesser saphenous vein from anterior tibial to dorsalis pedis artery (B).
estimator.18 To evaluate the effects of clinical characteristics on primary patency and limb loss, multivariate Cox proportional hazards regression models were performed. Variables that showed a P of less than .1 in univariate analysis were included in the adjusted model. Statistical analysis and graphic visualizations were performed using the R statistics environment (version 3.2.1, R Foundation for Statistical Computing, www.r-project. org; Vienna, Austria). A two-sided P value of less than .05 was considered statistically significant.
RESULTS Patients and bypass characteristics. A total of 881 bypasses to pedal arteries were performed between 1995 and 2017 at our institution, of which 61 (6.9%) were of tibial origin and therefore met the inclusion criteria. Indication for all bypasses was CLI. Thirty-three tibiodistal bypasses (54%) were procedures after previously unsuccessful tibial PTA (group B). PTA failed because it was impossible to cross the lesion in 21 (64%) extremities, it proved to be insufficient to heal the lesion in 11 (33%), and 1 (3%) occluded immediately after the intervention. The technical success rate was 100% in both bypass groups. Demographics, cardiovascular risk factors, preoperative Rutherford category,16 and bypass characteristics for groups A and B are shown in Tables I, II, and III. Patients in group A were significantly older than those in group B and significantly more bypasses originated
from the posterior tibial artery. Apart from that, the groups were similar. In group A, 17 patients (61%) presented with minor tissue loss (15 toe lesions, 2 forefoot lesions) and 11 (39%) with major tissue loss (7 forefoot lesion extending above transmetatarsal level, 4 heel lesions). In group B, 24 patients (73%) had minor tissue loss (20 toe lesions, 4 forefoot lesions) and 9 (27%) major tissue loss (5 forefoot lesion extending above transmetatarsal level, 4 heel lesions). In group A, five tibiodistal bypasses (18%; two femorocrural, one popliteocrural, two popliteopedal bypasses) whereas in group B, seven tibiodistal bypasses (21%; two femorocrural, three popliteocrural, two popliteopedal bypasses) were performed as redo procedures after a failed bypass with more proximal inflow. Previous proximal inflow corrections were performed in three patients in group A (two supragenual femoropopliteal bypasses, one superficial femoral artery PTA with bare metal stent) versus four in group B (one supragenual femoropopliteal bypass, three superficial femoral artery PTAs, two with bare metal stents; P ¼ .87). Postoperative antithrombotic medication in group A comprised aspirin (100 mg) combined with anticoagulation in 10 patients, aspirin only in 9, anticoagulation only in 2, aspirin with clopidogrel (75 mg) in 1, clopidogrel (75 mg) only in 1, and in group B aspirin with anticoagulation in 11 (P ¼ .97), aspirin only in 10 (P ¼ .31), anticoagulation only in 6 (P ¼ .20), aspirin with clopidogrel in 2 (P ¼ .65), and clopidogrel only in 1 (P ¼ .91).
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Table I. Demographics and cardiovascular risk factors Variable Mean age, years Male Body mass index, kg/m2 Hypertension Hyperlipidemia
Group A (n ¼ 28)
Group B (n ¼ 33)
70 6 11.2
Table III. Inflow and outflow arteries P
Variable
Group A (n ¼ 28)
Group B (n ¼ 33)
P .59
62 6 14.3
.02
19 (68)
25 (76)
.49
Anterior tibial artery
18 (64)
19 (58)
26.2 6 4.7
27.3 6 4.9
.38
Peroneal artery
9 (32)
5 (15)
.12
22 (79)
25 (76)
.80
Posterior tibial artery
1 (4)
8 (24)
.02
Tibioperoneal trunk
-
1 (3)
.35 .30
Inflow
12 (43)
17 (52)
.50
20 (71)
25 (76)
.70
CAD
9 (32)
12 (36)
.73
Dorsalis pedis artery
22 (78)
22 (67)
CABG
2 (7)
4 (12)
.52
Plantar artery
5 (18)
7 (21)
.74
Medial tarsal artery
1 (4)
3 (9)
.39
-
1 (3)
.35
Diabetes
Atrial fibrillation
5 (22)
10 (33)
.35
Carotid diseasea
14 (50)
12 (36)
.28
Stroke
4 (14)
3 (9)
.53
Kidney disease
9 (32)
8 (24)
.49
Hemodialysis
3 (11)
4 (12)
.86
Smoking history
8 (29)
10 (30)
.88
CABG, Coronary artery bypass graft; CAD, coronary artery disease. In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA). Continuous data are shown as mean 6 standard deviation and categoric data as n (%). a Internal carotid artery stenosis of >50%.
Table II. Preoperative Rutherford category16 and vein graft characteristics Group A (n ¼ 28)
Group B (n ¼ 33)
Rutherford category 5
17 (61)
24 (73)
.32
Rutherford category 6
11 (39)
9 (27)
.32
Redo bypassa
5 (18)
7 (21)
.74
21 (75)
24 (73)
.84
Lesser saphenous vein
6 (21)
9 (27)
.60
Arm vein
1 (4)
-
.27
21 (75)
24 (73)
.84
Variable
Greater saphenous vein
Reversed vein graft
P
Categoric data are shown as n (%). In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA). a Tibiodistal bypass performed after a failed bypass with more proximal inflow.
Antithrombotic medication in group A was only adapted in 4 cases. In two patients, owing to percutaneous coronary intervention, clopidogrel was added to aspirin only after more than 3 years. Aspirin was discontinued in two patients with aspirin and anticoagulation owing to bypass occlusion. In group B, two patients underwent percutaneous coronary intervention after more than 2 years and in one patient with aspirin and anticoagulation aspirin was discontinued because of bypass occlusion. Statins were used significantly less in group A (n ¼ 15; 54%) versus in group B (n ¼ 27; 82%; P ¼ .02), but this difference had no influence on patency, limb salvage, or survival.
Outflow
Peroneal artery
Categoric data are shown as n (%). In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA).
Primary study end points. The median follow-up was 4.0 years in group A and 4.9 years in group B. Eleven patients were lost to follow-up after a median time of 5.4 years. Primary patency in groups A and B was 55% versus 53% at 1 year and 47% versus 44% at 3 years (P ¼ .58; Fig 2, A), secondary patency at 1 year was 59% versus 64% and 52% versus 55% at 3 years (P ¼ .36; Fig 2, B). During follow-up, 14 reocclusions (50%) were recorded in group A, and 15 (45%) in group B (P ¼ .73). The 30-day patency rates were 86% in group A versus 94% in group B (P ¼ .28); this finding was significantly associated with wound healing (P ¼ .01). Repeat target extremity revascularizations were performed four times (14%) in group A, including two redo bypasses, one bypass thrombectomy, and one PTA in a failing graft for stenosis of the proximal anastomosis. Only one redo bypass and one PTA were successful. In group B, three revascularizations (9%) were carried out (P ¼ .53), two PTAs in failing grafts for bypass stenosis (one graft stenosis, one proximal anastomosis stenosis) and one redo bypass, all of them successful. In univariate Cox regression analysis, carotid disease (P ¼ .01) and minor amputation after bypass (P ¼ .02) were significant predictors for loss of primary patency, whereas wound healing reduced the risk significantly (P ¼ .01). Multivariate Cox regression provided no significant predictor for loss of primary patency (Table IV). There was also no difference between groups A and B in limb salvage rates with 96% versus 90% at 1 year and 91% versus 85% at 3 years (P ¼ .44; Fig 3, A). There were three major amputations, one above and two below knee, in group A versus six in group B, one above and five below the knee (P ¼ .41). In univariate Cox regression analysis, atrial fibrillation (P ¼ .03), CAD (P ¼ .02), CABG (P ¼ .01), and Rutherford category 6 (P ¼ .02) were significantly associated with limb loss. Wound healing, in
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1.0 + + +++ +
0.8
+ + ++
0.6
+
+
++ +
B
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
Secondary patency
Primary patency
A
+ ++
0.4
++ +
+
++
+
+
0.2
1.0 + +++ + +
0.8
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
+
+++ +
0.6
+
++
+
+ +
+
++
++
+
++ +
++
0.4 +
+
0.2
P = 0.58
P = 0.35 0.0
0.0 0
1
2
3 Time (years)
4
5
6
0
1
2
3 Time (years)
4
5
6
Primary bypass
No. at risk % SE (%)
10 54.7 10.4
8 54.7 10.4
6 46.9 11.5
4 39.1 11.9
2 29.3 12.3
2 29.3 12.3
Primary bypass
No. at risk % SE (%)
11 59.4 10.2
9 59.4 10.2
7 52.0 11.3
4 44.5 11.9
2 33.4 13.1
2 33.4 13.1
Unsuccessful PTA
No. at risk % SE (%)
14 53.2 9.3
12 53.2 9.3
10 44.4 9.6
7 44.4 9.6
5 44.4 9.6
4 44.4 9.6
Unsuccessful PTA
No. at risk % SE (%)
17 63.8 8.8
14 63.8 8.8
12 54.7 9.6
9 54.7 9.6
7 54.7 9.6
5 54.7 9.6
Fig 2. Kaplan-Meier estimates of primary (A) and secondary (B) patency in patients with primary tibiodistal bypass and tibiodistal bypass after unsuccessful tibial percutaneous transluminal angioplasty (PTA). SE, Standard error. Table IV. Analysis of factors associated with loss of primary patency Unadjusted
Adjusted
HR (95% CI)
P
Age > 65 years
1.11 (0.53-2.31)
.78
Atrial fibrillation
1.67 (0.76-3.70)
.20
CAD
1.60 (0.77-3.32)
.21
CABG
1.49 (0.52-4.30)
.46
Carotid disease
2.68 (1.26-5.70)
.01
Diabetes
0.72 (0.34-1.55)
.41
Variable
Female
1.70 (0.79-3.64)
.17
Hemodialysis
0.77 (0.23-2.56)
.67
Smoking history
0.91 (0.42-2.00)
.82
Rutherford category 6
1.25 (0.57-2.74)
.58
Planned minor amputation
2.6 (1.21-5.76)
.02
Wound healing
0.25 (0.09-0.70)
.01
Previous unsuccessful PTA
0.82 (0.40-1.67)
.58
Redo bypass
0.38 (0.09-1.61)
.19
Alternative vein graftb Reversed vein graft
1.43 (0.62-3.28)
.40
0.92 (0.39-2.18)
.85
HR (95% CI)
a
P
1.98 (0.86-4.58)
.11
1.93 (0.84-4.43)
.12
0.44 (0.15-1.32)
.14
CABG, Coronary artery bypass graft; CAD, coronary artery disease; CI, confidence interval; HR, hazard ratio; PTA, percutaneous transluminal angioplasty. a Variables identified in univariate analysis (P < .10) were included in a multivariate Cox proportional hazards model for associations with loss of primary patency. b Lesser saphenous vein, arm vein.
contrast, reduced the risk of major amputation significantly (P ¼ .002). Multivariate Cox regression analysis for limb loss provided no significant predictor (Table V). Secondary study end points. Survival rates in both groups were not significantly different with 91% versus 97% at 1 year and 85% versus 92% at 3 years (P ¼ .76; Fig 3, B). There were no periprocedural deaths within 30 days. Six deaths of unrelated causes occurred in
group A and eight in group B (P ¼ .76) during follow-up. Wound healing was achieved in 25 patients (89%) versus 27 (82%; P ¼ .41). Regarding systemic complications, there were no myocardial infarctions or strokes and one renal failure in group B, with one blood transfusion and one septic patient in each group. Local complications were not different between groups A (n ¼ 9; 32%) versus B (n ¼ 16; 48%; P ¼ .20). Unplanned minor amputations occurred in five cases (18%) in group A versus two (6%) in
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A
B
1.0
+++++++++ + +
+ +++++ + + ++
++ ++
+ ++ ++ ++ +
0.8
++ +
+++ + + ++ +
++ ++
+
0.8
+
+ ++ ++
Survival
Limb salvage
+++++ + +++ ++
1.0
+
0.6
0.4
0.2 P = 0.44
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
+
0.4
0.2 P = 0.76
0.0
++
0.6
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
0.0 0
1
2
3 Time (years)
4
5
6
0
1
2
3 Time (years)
4
5
6
Primary bypass
No. at risk % SE (%)
19 96.4 3.5
14 91.1 6.2
12 91.1 6.2
9 82.8 9.7
5 82.8 9.7
5 82.8 9.7
Primary bypass
No. at risk % SE (%)
19 90.9 6.2
15 85.2 8.0
13 85.2 8.0
11 78.6 9.7
6 71.5 11.1
6 71.5 11.1
Unsuccessful PTA
No. at risk % SE (%)
24 90.0 5.5
19 90.0 5.5
17 85.0 7.1
12 79.0 8.8
10 79.0 8.8
8 79.0 8.8
Unsuccessful PTA
No. at risk % SE (%)
25 96.8 3.2
20 92.4 5.3
19 92.4 5.3
15 86.6 7.5
12 74.6 10.2
9 68.4 11.1
Fig 3. Kaplan-Meier estimates of limb salvage (A) and survival (B) in patients with primary tibiodistal bypass and tibiodistal bypass after unsuccessful tibial percutaneous transluminal angioplasty (PTA). SE, Standard error.
Table V. Analysis of factors associated with limb loss Adjusteda
Unadjusted
HR (95% CI)
P
.03
1.56 (0.21-11.51)
.67
.02
3.96 (0.59-26.53)
.16
7.96 (1.87-33.97)
.01
1.70 (0.25-11.49)
.59
Carotid disease
2.05 (0.50-8.41)
.32
Diabetes
0.69 (0.16-2.88)
.61
Female
0.35 (0.04-2.86)
.32
3.92 (0.77-19.88)
.10
0.11 (0.01-1.56)
.10
Variable
HR (95% CI)
P
Age > 65 years
0.92 (0.21-3.99)
.91
Atrial fibrillation
5.38 (1.23-23.57)
CAD
6.71 (1.35-33.32)
CABG
Hemodialysis
1.12 (0.14-9.09)
.92
Smoking history
2.24 (0.56-8.96)
.26
Rutherford category 6
5.24 (1.24-22.18)
.02
1.14 (0.23-5.63)
.88
Planned minor amputation Wound healing
0.024 (0.002-0.26)
Previous unsuccessful PTA Redo bypass
1.72 (0.43-6.88) 0.93 (0.11-7.79)
b
.002 .44 .95
Alternative vein graft
0.58 (0.07-4.83)
.61
Reversed vein graft
1.80 (0.22-14.73)
.58
CABG, Coronary artery bypass graft; CAD, coronary artery disease; CI, confidence interval; HR, hazard ratio; PTA, percutaneous transluminal angioplasty. a Variables identified in univariate analysis (P < .10) were included in a multivariate Cox proportional hazards model for associations with limb loss. b Lesser saphenous vein, arm vein.
group B (P ¼ .15). In group A, significantly fewer planned minor amputations were performed with 3 (11%; 1 forefoot amputation) versus 11 (33%) in group B (P ¼ .04). Incisional SSIs were scarce, with one superficial SSI (4%) in group A and four superficial SSIs (12%) and one deep SSI (3%) in group B (P ¼ .20).
DISCUSSION Endovascular treatment has been massively expanded over the last years. An endovascular first strategy has
been increasingly dominating therapeutic considerations, even among vascular surgeons. Tibiodistal bypasses have been scarcely reported for more than 20 years with series of fewer than 10 patients per study as part of larger series with other bypasses.19-21 At our institution, tibiodistal bypasses are infrequently performed as well, with only 6.9% of all pedal procedures. To the best of our knowledge, this paper presents the largest series of this technique reported in the literature.
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Within the last 23 years, we have performed 61 tibiodistal vein bypasses. Twenty-eight were primary bypasses (46%) and 33 (54%) were performed after unsuccessful tibial angioplasty. The groups were comparable in terms of demographics, risk factors, indication for surgery, and procedural findings. Interestingly, patients in the previous unsuccessful tibial angioplasty group were significantly younger, with only 62 versus 70 years in the primary bypass group (P ¼ .02), which would be expected the other way around.22 In contrast with other studies, previously unsuccessful angioplasties of tibial arteries had no significant impact on primary or secondary patency, limb salvage, and survival of tibiodistal bypass.4-6 The primary patency rates in our study were relatively low for vein bypasses (55% in group A vs 53% in group B) at 1 year, compared with the results of Lyon et al,13 with 77%, or with a metaanalysis of popliteodistal bypasses with 81.5%.23 Our own distal bypasses with more proximal inflow are also performing better with primary patency rates of approximately 80% after 1 year. However, we have to keep in mind that those patients had very few surgical options, primarily owing to insufficient vein grafts. Tibiodistal vein bypasses were still outperforming synthetic grafts for infrapopliteal bypasses, especially regarding limb salvage.24 Despite low patency rates, limb salvage in groups A and B was comparable with 83% and 79% at 5 years in comparison with a range of 69% to 78% in literature for distal bypasses.13,20,21,23,25 Survival after 1 year (91% in group A and 97% in group B) and 5 years (72% in group A and 75% in group B) was even superior versus other distal bypass series ranging from 86% to 91% after 1 year and 48.6% to 64% after 5 years.13,20,21 Our high limb salvage rate could be explained by the high 30-day bypass patency, with 86% and 94% in groups A and B, respectively. It was significantly associated with wound healing, so presumably increased blood flow for at least several weeks was sufficient to heal the wounds and prevent major amputation. There were no perioperative deaths, strokes, or cardiac events in either group, despite the high number of comorbidities. Complication rates were low with only one renal failure, two septic patients, and two blood transfusions. The underlying cause for the low complication rates may be that the majority of procedures was done under regional anesthesia26 and the limited extent of surgical dissection in this technique.13 Infrapopliteal angioplasty in CLI seemingly provides low primary patency rates with high numbers of reinterventions, but acceptable limb salvage and survival reported from specialized centers.27-29 However, not all tibial lesions can be crossed, and even successful angioplasty of the target angiosome does not always lead to wound healing and limb salvage. To achieve wound healing, bypass surgery is significantly better than angioplasty.7,30
One may question the classification of 11 patients with no wound healing or clinical improvement after tibial angioplasty as unsuccessful PTA. Nevertheless, only one of the patients did not heal after subsequent tibiodistal bypass surgery. Even in the era of an endovascular first approach, we should not disregard distal bypass surgery. A crucial point seems to be to not compromise the distal outflow vessels for bypass surgery during tibial PTA. Tibiodistal bypass surgery provides a technique for critically ischemic legs with limited autologous vein material and no proximal arterial inflow lesions. The perioperative risks are low and surgical dissection is relatively small. It seems to be an efficient and safe technique, especially in combination with regional anesthesia, considering the number of high-risk patients in this study. In our experience, almost every patient has a suitable autologous vein graft for such a short bypass, if lesser saphenous vein and arm vein are also considered. This study has several limitations owing to its retrospective data collection over a period of 23 years. We lost 11 patients to follow-up after a median of 5.4 years. Also, the case number is relatively low, with only 61 procedures. The low number at risk especially affected patency estimates beyond 3 years. Patients eligible for primary tibiodistal bypass surgery who underwent tibial PTA, compromising their remaining outflow arteries, were not investigated in this study. We were not able to identify patterns of flow in the lower leg and foot, which would allow better prediction of healing with PTA alone.
CONCLUSIONS This study showed that tibiodistal vein bypass is a feasible, efficient, and safe technique in patients with CLI. It provides sufficient primary and secondary patency rates to prevent major amputation and ensure survival. Previous unsuccessful tibial angioplasty had no significant impact on tibiodistal vein bypass outcome. This rarely considered technique should be a part of the armamentarium of vascular surgeons. We want to thank Mark Adelman for sponsoring this study at the annual VESS Winter Meeting 2017.
AUTHOR CONTRIBUTIONS Conception and design: FE, TH Analysis and interpretation: FE, SE, MA, KL, TH Data collection: FE, TA, PN, TH Writing the article: FE, SE, MA, PN, KL, TH Critical revision of the article: FE, SE, TA, MA, PN, KL, TH Final approval of the article: FE, SE, TA, MA, PN, KL, TH Statistical analysis: FE, SE, TH Obtained funding: Not applicable Overall responsibility: TH
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REFERENCES 1. Kudo T, Chandra FA, Kwun WH, Haas BT, Ahn SS. Changing pattern of surgical revascularization for critical limb ischemia over 12 years: endovascular vs. open bypass surgery. J Vasc Surg 2006;44:304-13. 2. Adam DJ, Beard JD, Cleveland T, Bell J, Bradbury AW, Forbes JF, et al. Bypass versus angioplasty in severe ischaemia of the leg (BASIL): multicentre, randomised controlled trial. Lancet 2005;366:1925-34. 3. Abu Dabrh AM, Steffen MW, Asi N, Undavalli C, Wang Z, Elamin MB, et al. Bypass surgery versus endovascular interventions in severe or critical limb ischemia. J Vasc Surg 2016;63:244-53.e11. 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;54:730-5; discussion: 735-6. 5. Gifford SM, Fleming MD, Mendes BC, Stauffer KC, De Martino RR, Oderich GS, et al. Impact of femoropopliteal endovascular interventions on subsequent open bypass. J Vasc Surg 2016;64:623-8. 6. Bradbury AW, Adam DJ, Bell J, Forbes JF, Fowkes FG, Gillespie I, et al. Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: analysis of amputation free and overall survival by treatment received. J Vasc Surg 2010;51(5 Suppl):18S-31S. 7. Spillerova K, Biancari F, Leppaniemi A, Alback A, Soderstrom M, Venermo M. Differential impact of bypass surgery and angioplasty on angiosome-targeted infrapopliteal revascularization. Eur J Vasc Endovasc Surg 2015;49: 412-9. 8. Huang ZS, Schneider DB. Endovascular intervention for tibial artery occlusive disease in patients with critical limb ischemia. Semin Vasc Surg 2014;27:38-58. 9. Jaff MR, White CJ, Hiatt WR, Fowkes GR, Dormandy J, Razavi M, et al. An update on methods for revascularization and expansion of the TASC lesion classification to include below-the-knee arteries: a supplement to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II): The TASC Steering Committee. Ann Vasc Dis 2015;8:343-57. 10. Rooke TW, Hirsch AT, Misra S, Sidawy AN, Beckman JA, Findeiss LK, et al. 2011 ACCF/AHA focused update of the guideline for the management of patients with peripheral artery disease (updating the 2005 guideline): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2011;58:2020-45. 11. Veith FJ, Gupta SK, Samson RH, Flores SW, Janko G, Scher LA. Superficial femoral and popliteal arteries as inflow sites for distal bypasses. Surgery 1981;90:980-90. 12. Ascer E, Veith FJ, Gupta SK, White SA, Bakal CW, Wengerter K, et al. Short vein grafts: a superior option for arterial reconstructions to poor or compromised outflow tracts? J Vasc Surg 1988;7:370-8. 13. Lyon RT, Veith FJ, Marsan BU, Wengerter KR, Panetta TF, Marin ML, et al. Eleven-year experience with tibiotibial bypass: an unusual but effective solution to distal tibial artery occlusive disease and limited autologous vein. J Vasc Surg 1994;20:61-8; discussion: 68-9. 14. Danza R. The use of by-pass grafts for obstructive lesions of tibial and peroneal arteries. J Cardiovasc Surg 1982;23:59-64.
15. Domenig CM, Aspalter M, Umathum M, Holzenbein TJ. Redo pedal bypass surgery after pedal graft failure: gain or gadget? Ann Vasc Surg 2007;21:713-8. 16. Rutherford RB, Baker JD, Ernst C, Johnston KW, Porter JM, Ahn S, et al. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg 1997;26:517-38. 17. Neumayer L, Hosokawa P, Itani K, El-Tamer M, Henderson WG, Khuri SF. Multivariable predictors of postoperative surgical site infection after general and vascular surgery: results from the patient safety in surgery study. J Am Coll Surg 2007;204:1178-87. 18. Schemper M, Smith TL. A note on quantifying follow-up in studies of failure time. Control Clin Trial 1996;17:343-6. 19. Connors JP, Walsh DB, Nelson PR, Powell RJ, Fillinger MF, Zwolak RM, et al. Pedal branch artery bypass: a viable limb salvage option. J Vasc Surg 2000;32:1071-9. 20. 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. 21. Hughes 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. 22. Siracuse JJ, Menard MT, Eslami MH, Kalish JA, Robinson WP, Eberhardt RT, et al. Comparison of open and endovascular treatment of patients with critical limb ischemia in the Vascular Quality Initiative. J Vasc Surg 2016;63:958-65.e1. 23. Albers M, Romiti M, Brochado-Neto FC, De Luccia N, Pereira CA. Meta-analysis of popliteal-to-distal vein bypass grafts for critical ischemia. J Vasc Surg 2006;43:498-503. 24. Albers M, Battistella VM, Romiti M, Rodrigues AA, Pereira CA. Meta-analysis of polytetrafluoroethylene bypass grafts to infrapopliteal arteries. J Vasc Surg 2003;37:1263-9. 25. Pomposelli FB Jr, Marcaccio EJ, Gibbons GW, Campbell DR, Freeman DV, Burgess AM, et al. Dorsalis pedis arterial bypass: durable limb salvage for foot ischemia in patients with diabetes mellitus. J Vasc Surg 1995;21:375-84. 26. Saied NN, Helwani MA, Weavind LM, Shi Y, Shotwell MS, Pandharipande PP. Effect of anaesthesia type on postoperative mortality and morbidities: a matched analysis of the NSQIP database. Br J Anaesthes 2017;118:105-11. 27. Romiti M, Albers M, Brochado-Neto FC, Durazzo AE, Pereira CA, De Luccia N. Meta-analysis of infrapopliteal angioplasty for chronic critical limb ischemia. J Vasc Surg 2008;47:975-81. 28. Ambler GK, Stimpson AL, Wardle BG, Bosanquet DC, Hanif UK, Germain S, et al. Infrapopliteal angioplasty using a combined angiosomal reperfusion strategy. PLoS One 2017;12:e0172023. 29. Muir KB, Cook PR, Sirkin MR, Aidinian G. Tibioperoneal occlusive disease: a review of below the knee endovascular therapy in patients with critical limb ischemia. Ann Vasc Surg 2017;38:64-71. 30. Spillerova K, Settembre N, Biancari F, Alback A, Venermo M. Angiosome targeted PTA is more important in endovascular revascularisation than in surgical revascularisation: analysis of 545 patients with ischaemic tissue lesions. Eur J Vasc Endovasc Surg 2017;53:567-75.
Submitted May 10, 2017; accepted Jul 22, 2017.
Tibiodistal vein bypass in critical limb ischemia and its role after unsuccessful tibial angioplasty Florian K. Enzmann, MD,a Sebastian K. Eder, MD,a Thomas Aschacher, MD,b Manuela Aspalter, MD,a Patrick Nierlich, MD, PhD,a Klaus Linni, MD,a and Thomas J. Hölzenbein, MD,a Salzburg and Vienna, Austria
ABSTRACT Objective: Technical progress in angioplasty expanded its application to very distal arterial lesions of the lower extremity. In cases of unsuccessful angioplasty tibiodistal bypass surgery may be required for limb salvage. We investigated the long-term outcome of this technique in patients with critical limb ischemia. The purpose of this study was to evaluate whether tibiodistal bypasses done after unsuccessful tibial angioplasty had inferior patency, limb salvage, or survival rates compared with primary tibiodistal bypasses. Methods: This single-center, retrospective data analysis included all distal bypass procedures originating from a tibial artery. Primary study end points were primary patency, secondary patency, and limb salvage. Secondary end points included survival, wound healing, and systemic and local complications. Society for Vascular Surgery reporting standards were applied. Results: There were 61 tibiodistal vein bypasses for critical limb ischemia performed in 23 years. Indications for tibiodistal bypass was Rutherford category 5 in 41 cases (67%) and category 6 in 20 cases (33%). Procedures were allocated to group A (primary bypass; n ¼ 28) and group B (bypass after unsuccessful tibial angioplasty; n ¼ 33). Primary patency was 55% versus 53% at 1 year and 47% versus 44% at 3 years (P ¼ .58). Secondary patency was 59% versus 64% at 1 year and 52% versus 55% at 3 years (P ¼ .36). Limb salvage was 96% versus 90% at 1 year and 91% versus 85% at 3 years (P ¼ .44). Overall survival rates were 91% versus 97% at 1 year and 85% versus 92% at 3 years (P ¼ .76). The median follow-up was 4.0 years in group A and 4.9 years in group B. In multivariate analyses for loss of primary patency and limb loss, no significant predictors could be identified. Conclusions: This study showed that tibiodistal vein bypass is a feasible, efficient, and safe technique in patients with critical limb ischemia. It provides acceptable primary and secondary patency rates to prevent major amputation and ensure survival. Previous unsuccessful tibial angioplasty had no significant impact on tibiodistal vein bypass outcome. This technique should be part of the armamentarium of vascular surgeons. (J Vasc Surg 2018;67:1191-8.)
Since the 1990s, tibial percutaneous transluminal angioplasty (PTA) is increasingly advocated and considered as feasible, safe, and effective in critical limb ischemia (CLI)1 with similar outcomes compared with bypass surgery.2,3 In contrast, there is growing evidence of inferior outcome in patients undergoing bypass surgery after failed infrainguinal PTA4-6 and poorer wound healing after infrapopliteal PTA compared with bypass surgery.7,8
From the Department of Vascular and Endovascular Surgery, Paracelsus Medical University Salzburg, Salzburga; and the Department of Surgery, Cardiac Surgery, Medical University of Vienna, Vienna.b Author conflict of interest: none. Presented at the 2017 Annual Winter Meeting of the Vascular and Endovascular Surgery Society, Steamboat Springs, Colo, February 2-5, 2017. Correspondence: Florian K. Enzmann, MD, Department of Vascular and Endovascular Surgery, Paracelsus Medical University Salzburg, Müllner Hauptstrasse 48, Salzburg A-5020, Austria (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 Copyright Ó 2017 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2017.07.127
Some authors prefer an endovascular first approach,9 whereas the American College of Cardiology Foundation/American Heart Association stated that a bypass surgery first approach is reasonable in CLI patients with a life expectancy of more than 2 years and useable vein grafts.10 The decision making process, whether an unconditional endovascular first strategy for isolated tibial lesions is sustainable in contrast to primary distal bypass surgery, was particularly interesting for us. Distal bypass procedures usually originated from the common femoral artery until Veith et al11 introduced the short bypass principle in 1981. Superficial femoral and popliteal artery were shown to be suitable inflow sites for distal bypasses.11 The advantages of the resulting shorter bypasses are short vein grafts are reported to have better patency,12 and it is possible to limit the extend of surgical dissection and reduce operative time.13 Additionally, bypass length can be kept as short as possible in cases of limited vein graft owing to prior coronary artery bypass procedure, varicose vein treatment or previous peripheral bypass surgery.13 In 1982, Danza14 was the first to report 10 distal bypasses originating from tibial arteries as part of a larger case series. 1191
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There was only one dedicated report 23 years ago, describing 42 tibiodistal bypasses by the Veith group with primary patency and limb salvage rates in patients with CLI comparable with those of femorotibial bypasses.13 In the era of endovascular first procedures for isolated tibial lesions tibiodistal bypass may deserve a renaissance especially as a bail-out technique after unsuccessful PTA. The aim of this study was to evaluate whether the technique of tibiodistal bypass after unsuccessful tibial PTA had inferior patency, limb salvage, or survival rates compared with primary tibiodistal bypass in patients with CLI.
METHODS We performed a single-center, retrospective data analysis of all distal bypass procedures originating from a tibial artery (anterior tibial artery, posterior tibial artery, peroneal artery) performed from 1995 to 2017. Patients undergoing a primary bypass were categorized as group A and patients undergoing tibiodistal bypass as a bailout procedure after unsuccessful tibial PTA as group B (Fig 1). The institutional review board approved the study and waived a requirement for informed patient consent because of its retrospective design. All pedal bypasses were performed in an academic tertiary referral center. Distal redo bypass procedures were included.15 Bypasses originating from the popliteal or more proximal arteries as well as grafts performed as distal extensions from previous bypasses were excluded. The collected data included patient characteristics, technical data of the bypass procedure, local and systemic complications, reinterventions, and follow-up. Indication. Tibiodistal bypass surgery was performed in patients with tissue loss in all cases, classified according to the Rutherford categories 5 or 6.16 Management included revascularization before minor amputation and debridement. There were no significant proximal inflow lesions at the time of tibiodistal bypass procedure. Angioplasty. If PTA of the tibial arteries was attempted before the bypass procedure, it was either impossible to cross the lesion to the patent pedal artery, occluded soon after the intervention, or proved to be insufficient to heal the lesions and provided no clinical improvement. Operative technique and follow-up. Operative technique included standard tibial and pedal artery exposure, systemic heparinization, and completion digital subtraction angiography. We performed all bypasses with autologous vein grafts. The postoperative antithrombotic medication was at the discretion of the surgeon and was individually adapted to the comorbidities of patients (eg, atrial fibrillation, coronary artery disease).
ARTICLE HIGHLIGHTS d
d
d
Type of Research: Single-center retrospective cohort study Take Home Message: In a group of 61 tibiodistal bypasses performed for patients with critical limb ischemia who underwent unsuccessful angioplasty before bypass had 3-year primary and secondary patencies and limb salvage of 44%, 55%, and 85%, respectively, not significantly different from those who had no previous angioplasty (47%, 52%, and 91%, respectively). Recommendation: This study suggests that unsuccessful tibial angioplasty does not diminish the very acceptable patency rates or limb salvage of tibiodistal bypasses performed for critical limb ischemia.
Follow-up started at the day after bypass procedure and patients were usually examined at our outpatient clinic after 1, 3, 6, and 12 months, followed by visits at yearly intervals. This included a clinical examination, hand-held doppler ultrasound and measurements of the ankle-brachial index. In cases of clinical or anklebrachial index deterioration, duplex sonography of the bypass graft was performed. Definitions and study end points. According to the criteria established by the Society of Vascular Surgery, primary patency was defined as freedom from reintervention to maintain bypass patency. Secondary patency included all interventions to restore patency after occlusion.16 The primary study end points were primary patency, secondary patency, and limb salvage. Secondary end points included survival, wound healing, systemic complications (myocardial infarction, stroke, renal failure, blood transfusion, sepsis), and local complications like unplanned, late minor amputation (after >3 months) and surgical site infection (SSI), which was categorized as superficial incisional SSI or deep incisional SSI.17 Statistical analysis. To evaluate differences between the groups, demographics, cardiovascular risk factors, preoperative Rutherford category,16 and bypass characteristics were compared. All normally distributed continuous variables are expressed as means and standard deviations and were compared using the Student t test. Categorical variables are reported as frequencies and analyzed using the c2 test. The Kaplan-Meier method was used to estimate primary patency, secondary patency, limb salvage, and overall survival for primary bypass and previous unsuccessful PTA subjects, respectively. Group differences were assessed with log-rank tests. The median followup time was assessed using the reverse Kaplan-Meier
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Fig 1. Tibiodistal vein bypass after unsuccessful percutaneous transluminal angioplasty (PTA) of the distal anterior tibial artery (A), performed with reversed lesser saphenous vein from anterior tibial to dorsalis pedis artery (B).
estimator.18 To evaluate the effects of clinical characteristics on primary patency and limb loss, multivariate Cox proportional hazards regression models were performed. Variables that showed a P of less than .1 in univariate analysis were included in the adjusted model. Statistical analysis and graphic visualizations were performed using the R statistics environment (version 3.2.1, R Foundation for Statistical Computing, www.r-project. org; Vienna, Austria). A two-sided P value of less than .05 was considered statistically significant.
RESULTS Patients and bypass characteristics. A total of 881 bypasses to pedal arteries were performed between 1995 and 2017 at our institution, of which 61 (6.9%) were of tibial origin and therefore met the inclusion criteria. Indication for all bypasses was CLI. Thirty-three tibiodistal bypasses (54%) were procedures after previously unsuccessful tibial PTA (group B). PTA failed because it was impossible to cross the lesion in 21 (64%) extremities, it proved to be insufficient to heal the lesion in 11 (33%), and 1 (3%) occluded immediately after the intervention. The technical success rate was 100% in both bypass groups. Demographics, cardiovascular risk factors, preoperative Rutherford category,16 and bypass characteristics for groups A and B are shown in Tables I, II, and III. Patients in group A were significantly older than those in group B and significantly more bypasses originated
from the posterior tibial artery. Apart from that, the groups were similar. In group A, 17 patients (61%) presented with minor tissue loss (15 toe lesions, 2 forefoot lesions) and 11 (39%) with major tissue loss (7 forefoot lesion extending above transmetatarsal level, 4 heel lesions). In group B, 24 patients (73%) had minor tissue loss (20 toe lesions, 4 forefoot lesions) and 9 (27%) major tissue loss (5 forefoot lesion extending above transmetatarsal level, 4 heel lesions). In group A, five tibiodistal bypasses (18%; two femorocrural, one popliteocrural, two popliteopedal bypasses) whereas in group B, seven tibiodistal bypasses (21%; two femorocrural, three popliteocrural, two popliteopedal bypasses) were performed as redo procedures after a failed bypass with more proximal inflow. Previous proximal inflow corrections were performed in three patients in group A (two supragenual femoropopliteal bypasses, one superficial femoral artery PTA with bare metal stent) versus four in group B (one supragenual femoropopliteal bypass, three superficial femoral artery PTAs, two with bare metal stents; P ¼ .87). Postoperative antithrombotic medication in group A comprised aspirin (100 mg) combined with anticoagulation in 10 patients, aspirin only in 9, anticoagulation only in 2, aspirin with clopidogrel (75 mg) in 1, clopidogrel (75 mg) only in 1, and in group B aspirin with anticoagulation in 11 (P ¼ .97), aspirin only in 10 (P ¼ .31), anticoagulation only in 6 (P ¼ .20), aspirin with clopidogrel in 2 (P ¼ .65), and clopidogrel only in 1 (P ¼ .91).
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Table I. Demographics and cardiovascular risk factors Variable Mean age, years Male Body mass index, kg/m2 Hypertension Hyperlipidemia
Group A (n ¼ 28)
Group B (n ¼ 33)
70 6 11.2
Table III. Inflow and outflow arteries P
Variable
Group A (n ¼ 28)
Group B (n ¼ 33)
P .59
62 6 14.3
.02
19 (68)
25 (76)
.49
Anterior tibial artery
18 (64)
19 (58)
26.2 6 4.7
27.3 6 4.9
.38
Peroneal artery
9 (32)
5 (15)
.12
22 (79)
25 (76)
.80
Posterior tibial artery
1 (4)
8 (24)
.02
Tibioperoneal trunk
-
1 (3)
.35 .30
Inflow
12 (43)
17 (52)
.50
20 (71)
25 (76)
.70
CAD
9 (32)
12 (36)
.73
Dorsalis pedis artery
22 (78)
22 (67)
CABG
2 (7)
4 (12)
.52
Plantar artery
5 (18)
7 (21)
.74
Medial tarsal artery
1 (4)
3 (9)
.39
-
1 (3)
.35
Diabetes
Atrial fibrillation
5 (22)
10 (33)
.35
Carotid diseasea
14 (50)
12 (36)
.28
Stroke
4 (14)
3 (9)
.53
Kidney disease
9 (32)
8 (24)
.49
Hemodialysis
3 (11)
4 (12)
.86
Smoking history
8 (29)
10 (30)
.88
CABG, Coronary artery bypass graft; CAD, coronary artery disease. In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA). Continuous data are shown as mean 6 standard deviation and categoric data as n (%). a Internal carotid artery stenosis of >50%.
Table II. Preoperative Rutherford category16 and vein graft characteristics Group A (n ¼ 28)
Group B (n ¼ 33)
Rutherford category 5
17 (61)
24 (73)
.32
Rutherford category 6
11 (39)
9 (27)
.32
Redo bypassa
5 (18)
7 (21)
.74
21 (75)
24 (73)
.84
Lesser saphenous vein
6 (21)
9 (27)
.60
Arm vein
1 (4)
-
.27
21 (75)
24 (73)
.84
Variable
Greater saphenous vein
Reversed vein graft
P
Categoric data are shown as n (%). In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA). a Tibiodistal bypass performed after a failed bypass with more proximal inflow.
Antithrombotic medication in group A was only adapted in 4 cases. In two patients, owing to percutaneous coronary intervention, clopidogrel was added to aspirin only after more than 3 years. Aspirin was discontinued in two patients with aspirin and anticoagulation owing to bypass occlusion. In group B, two patients underwent percutaneous coronary intervention after more than 2 years and in one patient with aspirin and anticoagulation aspirin was discontinued because of bypass occlusion. Statins were used significantly less in group A (n ¼ 15; 54%) versus in group B (n ¼ 27; 82%; P ¼ .02), but this difference had no influence on patency, limb salvage, or survival.
Outflow
Peroneal artery
Categoric data are shown as n (%). In group A, patients were treated with tibiodistal vein bypass for critical limb ischemia (CLI) as the primary procedure; group B included patients so treated after an unsuccessful percutaneous transluminal angioplasty (PTA).
Primary study end points. The median follow-up was 4.0 years in group A and 4.9 years in group B. Eleven patients were lost to follow-up after a median time of 5.4 years. Primary patency in groups A and B was 55% versus 53% at 1 year and 47% versus 44% at 3 years (P ¼ .58; Fig 2, A), secondary patency at 1 year was 59% versus 64% and 52% versus 55% at 3 years (P ¼ .36; Fig 2, B). During follow-up, 14 reocclusions (50%) were recorded in group A, and 15 (45%) in group B (P ¼ .73). The 30-day patency rates were 86% in group A versus 94% in group B (P ¼ .28); this finding was significantly associated with wound healing (P ¼ .01). Repeat target extremity revascularizations were performed four times (14%) in group A, including two redo bypasses, one bypass thrombectomy, and one PTA in a failing graft for stenosis of the proximal anastomosis. Only one redo bypass and one PTA were successful. In group B, three revascularizations (9%) were carried out (P ¼ .53), two PTAs in failing grafts for bypass stenosis (one graft stenosis, one proximal anastomosis stenosis) and one redo bypass, all of them successful. In univariate Cox regression analysis, carotid disease (P ¼ .01) and minor amputation after bypass (P ¼ .02) were significant predictors for loss of primary patency, whereas wound healing reduced the risk significantly (P ¼ .01). Multivariate Cox regression provided no significant predictor for loss of primary patency (Table IV). There was also no difference between groups A and B in limb salvage rates with 96% versus 90% at 1 year and 91% versus 85% at 3 years (P ¼ .44; Fig 3, A). There were three major amputations, one above and two below knee, in group A versus six in group B, one above and five below the knee (P ¼ .41). In univariate Cox regression analysis, atrial fibrillation (P ¼ .03), CAD (P ¼ .02), CABG (P ¼ .01), and Rutherford category 6 (P ¼ .02) were significantly associated with limb loss. Wound healing, in
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1.0 + + +++ +
0.8
+ + ++
0.6
+
+
++ +
B
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
Secondary patency
Primary patency
A
+ ++
0.4
++ +
+
++
+
+
0.2
1.0 + +++ + +
0.8
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
+
+++ +
0.6
+
++
+
+ +
+
++
++
+
++ +
++
0.4 +
+
0.2
P = 0.58
P = 0.35 0.0
0.0 0
1
2
3 Time (years)
4
5
6
0
1
2
3 Time (years)
4
5
6
Primary bypass
No. at risk % SE (%)
10 54.7 10.4
8 54.7 10.4
6 46.9 11.5
4 39.1 11.9
2 29.3 12.3
2 29.3 12.3
Primary bypass
No. at risk % SE (%)
11 59.4 10.2
9 59.4 10.2
7 52.0 11.3
4 44.5 11.9
2 33.4 13.1
2 33.4 13.1
Unsuccessful PTA
No. at risk % SE (%)
14 53.2 9.3
12 53.2 9.3
10 44.4 9.6
7 44.4 9.6
5 44.4 9.6
4 44.4 9.6
Unsuccessful PTA
No. at risk % SE (%)
17 63.8 8.8
14 63.8 8.8
12 54.7 9.6
9 54.7 9.6
7 54.7 9.6
5 54.7 9.6
Fig 2. Kaplan-Meier estimates of primary (A) and secondary (B) patency in patients with primary tibiodistal bypass and tibiodistal bypass after unsuccessful tibial percutaneous transluminal angioplasty (PTA). SE, Standard error. Table IV. Analysis of factors associated with loss of primary patency Unadjusted
Adjusted
HR (95% CI)
P
Age > 65 years
1.11 (0.53-2.31)
.78
Atrial fibrillation
1.67 (0.76-3.70)
.20
CAD
1.60 (0.77-3.32)
.21
CABG
1.49 (0.52-4.30)
.46
Carotid disease
2.68 (1.26-5.70)
.01
Diabetes
0.72 (0.34-1.55)
.41
Variable
Female
1.70 (0.79-3.64)
.17
Hemodialysis
0.77 (0.23-2.56)
.67
Smoking history
0.91 (0.42-2.00)
.82
Rutherford category 6
1.25 (0.57-2.74)
.58
Planned minor amputation
2.6 (1.21-5.76)
.02
Wound healing
0.25 (0.09-0.70)
.01
Previous unsuccessful PTA
0.82 (0.40-1.67)
.58
Redo bypass
0.38 (0.09-1.61)
.19
Alternative vein graftb Reversed vein graft
1.43 (0.62-3.28)
.40
0.92 (0.39-2.18)
.85
HR (95% CI)
a
P
1.98 (0.86-4.58)
.11
1.93 (0.84-4.43)
.12
0.44 (0.15-1.32)
.14
CABG, Coronary artery bypass graft; CAD, coronary artery disease; CI, confidence interval; HR, hazard ratio; PTA, percutaneous transluminal angioplasty. a Variables identified in univariate analysis (P < .10) were included in a multivariate Cox proportional hazards model for associations with loss of primary patency. b Lesser saphenous vein, arm vein.
contrast, reduced the risk of major amputation significantly (P ¼ .002). Multivariate Cox regression analysis for limb loss provided no significant predictor (Table V). Secondary study end points. Survival rates in both groups were not significantly different with 91% versus 97% at 1 year and 85% versus 92% at 3 years (P ¼ .76; Fig 3, B). There were no periprocedural deaths within 30 days. Six deaths of unrelated causes occurred in
group A and eight in group B (P ¼ .76) during follow-up. Wound healing was achieved in 25 patients (89%) versus 27 (82%; P ¼ .41). Regarding systemic complications, there were no myocardial infarctions or strokes and one renal failure in group B, with one blood transfusion and one septic patient in each group. Local complications were not different between groups A (n ¼ 9; 32%) versus B (n ¼ 16; 48%; P ¼ .20). Unplanned minor amputations occurred in five cases (18%) in group A versus two (6%) in
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A
B
1.0
+++++++++ + +
+ +++++ + + ++
++ ++
+ ++ ++ ++ +
0.8
++ +
+++ + + ++ +
++ ++
+
0.8
+
+ ++ ++
Survival
Limb salvage
+++++ + +++ ++
1.0
+
0.6
0.4
0.2 P = 0.44
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
+
0.4
0.2 P = 0.76
0.0
++
0.6
+
Primary bypass (n = 28)
+
Unsuccessful PTA (n = 33)
0.0 0
1
2
3 Time (years)
4
5
6
0
1
2
3 Time (years)
4
5
6
Primary bypass
No. at risk % SE (%)
19 96.4 3.5
14 91.1 6.2
12 91.1 6.2
9 82.8 9.7
5 82.8 9.7
5 82.8 9.7
Primary bypass
No. at risk % SE (%)
19 90.9 6.2
15 85.2 8.0
13 85.2 8.0
11 78.6 9.7
6 71.5 11.1
6 71.5 11.1
Unsuccessful PTA
No. at risk % SE (%)
24 90.0 5.5
19 90.0 5.5
17 85.0 7.1
12 79.0 8.8
10 79.0 8.8
8 79.0 8.8
Unsuccessful PTA
No. at risk % SE (%)
25 96.8 3.2
20 92.4 5.3
19 92.4 5.3
15 86.6 7.5
12 74.6 10.2
9 68.4 11.1
Fig 3. Kaplan-Meier estimates of limb salvage (A) and survival (B) in patients with primary tibiodistal bypass and tibiodistal bypass after unsuccessful tibial percutaneous transluminal angioplasty (PTA). SE, Standard error.
Table V. Analysis of factors associated with limb loss Adjusteda
Unadjusted
HR (95% CI)
P
.03
1.56 (0.21-11.51)
.67
.02
3.96 (0.59-26.53)
.16
7.96 (1.87-33.97)
.01
1.70 (0.25-11.49)
.59
Carotid disease
2.05 (0.50-8.41)
.32
Diabetes
0.69 (0.16-2.88)
.61
Female
0.35 (0.04-2.86)
.32
3.92 (0.77-19.88)
.10
0.11 (0.01-1.56)
.10
Variable
HR (95% CI)
P
Age > 65 years
0.92 (0.21-3.99)
.91
Atrial fibrillation
5.38 (1.23-23.57)
CAD
6.71 (1.35-33.32)
CABG
Hemodialysis
1.12 (0.14-9.09)
.92
Smoking history
2.24 (0.56-8.96)
.26
Rutherford category 6
5.24 (1.24-22.18)
.02
1.14 (0.23-5.63)
.88
Planned minor amputation Wound healing
0.024 (0.002-0.26)
Previous unsuccessful PTA Redo bypass
1.72 (0.43-6.88) 0.93 (0.11-7.79)
b
.002 .44 .95
Alternative vein graft
0.58 (0.07-4.83)
.61
Reversed vein graft
1.80 (0.22-14.73)
.58
CABG, Coronary artery bypass graft; CAD, coronary artery disease; CI, confidence interval; HR, hazard ratio; PTA, percutaneous transluminal angioplasty. a Variables identified in univariate analysis (P < .10) were included in a multivariate Cox proportional hazards model for associations with limb loss. b Lesser saphenous vein, arm vein.
group B (P ¼ .15). In group A, significantly fewer planned minor amputations were performed with 3 (11%; 1 forefoot amputation) versus 11 (33%) in group B (P ¼ .04). Incisional SSIs were scarce, with one superficial SSI (4%) in group A and four superficial SSIs (12%) and one deep SSI (3%) in group B (P ¼ .20).
DISCUSSION Endovascular treatment has been massively expanded over the last years. An endovascular first strategy has
been increasingly dominating therapeutic considerations, even among vascular surgeons. Tibiodistal bypasses have been scarcely reported for more than 20 years with series of fewer than 10 patients per study as part of larger series with other bypasses.19-21 At our institution, tibiodistal bypasses are infrequently performed as well, with only 6.9% of all pedal procedures. To the best of our knowledge, this paper presents the largest series of this technique reported in the literature.
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Within the last 23 years, we have performed 61 tibiodistal vein bypasses. Twenty-eight were primary bypasses (46%) and 33 (54%) were performed after unsuccessful tibial angioplasty. The groups were comparable in terms of demographics, risk factors, indication for surgery, and procedural findings. Interestingly, patients in the previous unsuccessful tibial angioplasty group were significantly younger, with only 62 versus 70 years in the primary bypass group (P ¼ .02), which would be expected the other way around.22 In contrast with other studies, previously unsuccessful angioplasties of tibial arteries had no significant impact on primary or secondary patency, limb salvage, and survival of tibiodistal bypass.4-6 The primary patency rates in our study were relatively low for vein bypasses (55% in group A vs 53% in group B) at 1 year, compared with the results of Lyon et al,13 with 77%, or with a metaanalysis of popliteodistal bypasses with 81.5%.23 Our own distal bypasses with more proximal inflow are also performing better with primary patency rates of approximately 80% after 1 year. However, we have to keep in mind that those patients had very few surgical options, primarily owing to insufficient vein grafts. Tibiodistal vein bypasses were still outperforming synthetic grafts for infrapopliteal bypasses, especially regarding limb salvage.24 Despite low patency rates, limb salvage in groups A and B was comparable with 83% and 79% at 5 years in comparison with a range of 69% to 78% in literature for distal bypasses.13,20,21,23,25 Survival after 1 year (91% in group A and 97% in group B) and 5 years (72% in group A and 75% in group B) was even superior versus other distal bypass series ranging from 86% to 91% after 1 year and 48.6% to 64% after 5 years.13,20,21 Our high limb salvage rate could be explained by the high 30-day bypass patency, with 86% and 94% in groups A and B, respectively. It was significantly associated with wound healing, so presumably increased blood flow for at least several weeks was sufficient to heal the wounds and prevent major amputation. There were no perioperative deaths, strokes, or cardiac events in either group, despite the high number of comorbidities. Complication rates were low with only one renal failure, two septic patients, and two blood transfusions. The underlying cause for the low complication rates may be that the majority of procedures was done under regional anesthesia26 and the limited extent of surgical dissection in this technique.13 Infrapopliteal angioplasty in CLI seemingly provides low primary patency rates with high numbers of reinterventions, but acceptable limb salvage and survival reported from specialized centers.27-29 However, not all tibial lesions can be crossed, and even successful angioplasty of the target angiosome does not always lead to wound healing and limb salvage. To achieve wound healing, bypass surgery is significantly better than angioplasty.7,30
One may question the classification of 11 patients with no wound healing or clinical improvement after tibial angioplasty as unsuccessful PTA. Nevertheless, only one of the patients did not heal after subsequent tibiodistal bypass surgery. Even in the era of an endovascular first approach, we should not disregard distal bypass surgery. A crucial point seems to be to not compromise the distal outflow vessels for bypass surgery during tibial PTA. Tibiodistal bypass surgery provides a technique for critically ischemic legs with limited autologous vein material and no proximal arterial inflow lesions. The perioperative risks are low and surgical dissection is relatively small. It seems to be an efficient and safe technique, especially in combination with regional anesthesia, considering the number of high-risk patients in this study. In our experience, almost every patient has a suitable autologous vein graft for such a short bypass, if lesser saphenous vein and arm vein are also considered. This study has several limitations owing to its retrospective data collection over a period of 23 years. We lost 11 patients to follow-up after a median of 5.4 years. Also, the case number is relatively low, with only 61 procedures. The low number at risk especially affected patency estimates beyond 3 years. Patients eligible for primary tibiodistal bypass surgery who underwent tibial PTA, compromising their remaining outflow arteries, were not investigated in this study. We were not able to identify patterns of flow in the lower leg and foot, which would allow better prediction of healing with PTA alone.
CONCLUSIONS This study showed that tibiodistal vein bypass is a feasible, efficient, and safe technique in patients with CLI. It provides sufficient primary and secondary patency rates to prevent major amputation and ensure survival. Previous unsuccessful tibial angioplasty had no significant impact on tibiodistal vein bypass outcome. This rarely considered technique should be a part of the armamentarium of vascular surgeons. We want to thank Mark Adelman for sponsoring this study at the annual VESS Winter Meeting 2017.
AUTHOR CONTRIBUTIONS Conception and design: FE, TH Analysis and interpretation: FE, SE, MA, KL, TH Data collection: FE, TA, PN, TH Writing the article: FE, SE, MA, PN, KL, TH Critical revision of the article: FE, SE, TA, MA, PN, KL, TH Final approval of the article: FE, SE, TA, MA, PN, KL, TH Statistical analysis: FE, SE, TH Obtained funding: Not applicable Overall responsibility: TH
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Submitted May 10, 2017; accepted Jul 22, 2017.