A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia

t h e s u r g e o n x x x ( 2 0 1 5 ) 1 e7

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A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia €pel, S. Bro €ckner, M. Steinbauer, C. Uhl* C. Hock, T. Betz, I. To Department of Vascular Surgery, Hospital Barmherzige Bru¨der Regensburg, Germany

article info

abstract

Article history:

Objective: In this study we analyzed the outcome of tibial and peroneal venous and heparin-

Received 24 January 2015

bonded expanded polytetrafluoroethylene (HePTFE) bypasses in diabetics with critical limb

Received in revised form

ischemia (CLI). We aimed to verify our hypothesis that HePTFE grafts will achieve

10 June 2015

acceptable 1-year patency and limb salvage results in patients who lack an adequate vein.

Accepted 12 June 2015

Methods: We conducted a retrospective analysis for all diabetics who underwent tibial

Available online xxx

bypass surgery in our department between October 2007 and October 2012. The study includes 97 grafts. All these patients were not suited for an endovascular therapy. We used

Keywords:

autologous veins in 56 cases (Vein-Group) and HePTFE grafts in 41 cases (HePTFE-Group).

Diabetes mellitus

Study endpoints were primary and secondary patency, limb salvage, and survival at 2 years

Tibial and peroneal bypasses

postoperatively.

Critical limb ischemia

Results: Risk factors and indications were similar in both groups. The comparison between HePTFE- and Vein-Group showed significantly different patency rates. At 2 years, primary patency was 39.3% in HePTFE-Group vs. 78.5% in VeinGroup (P ¼ .003) and secondary patency was 47.4% vs. 81.9% (P ¼ .002). Limb salvage at 2 years was 79.3% vs. 87.4% (P ¼ .073) and survival was 64.6% vs. 62.9% (P ¼ .593) at the 2-year mark, with no significant differences. 30-days mortality, graft occlusion and major amputation rate showed no significant differences, either. Conclusions: This study shows that HePTFE bypasses are a viable option for diabetics undergoing tibial bypass surgery when no adequate vein is available. © 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Introduction With an annual incidence of roughly 500e1000 new cases per 1 million, critical limb ischemia (CLI) is on the rise, affecting

the quality of life of many patients worldwide.1 Diabetes is a well-known risk factor for CLI. Interventional endovascular therapy and bypass surgery present the best treatment options for arterial occlusions. Both venous and prosthetic grafts are being used as bypass material in patients with CLI.

* Corresponding author. Krankenhaus Barmherzige Bru¨der Regensburg, Pru¨feningerstraße 86, 93049 Regensburg, Germany. Tel.: þ49 941 3692221. E-mail address: [email protected] (C. Uhl). http://dx.doi.org/10.1016/j.surge.2015.06.005 1479-666X/© 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

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Previous studies have suggested that diabetics and nondiabetics fare similar after bypass surgery and have similar patency and limb salvage rates.2 Other studies were able to demonstrate a worse outcome and significantly shorter amputation-free survival periods for bypasses in diabetics with CLI.3 However, these studies included all kinds of bypasses. The outcome of exclusively tibial and peroneal bypasses in diabetics is still insufficiently analyzed. Previous studies did not include data regarding prior revascularization procedures, the feasibility of alternative interventional therapies, or data on indications and results for different graft materials. It is therefore unclear to what extent the chosen graft material might influence the outcome of bypass surgery in diabetic patients. The aim of this study was to analyze the outcome of venous and HePTFE tibial and peroneal bypasses in diabetics with CLI who were unsuitable for endovascular therapy.

Methods We conducted a retrospective analysis for all diabetics who underwent tibial bypass surgery in our department between October 2007 and October 2012. Indication was in all cases CLI (Rutherford 4e6). During the same period we performed 274 successful femoro-tibial and femoro-peroneal endovascular interventions in diabetics as first line therapy. The decision what type of revascularization procedure a patient should undergo was made by an interdisciplinary board of experts (interventional radiologists, angiologists, and vascular surgeons). Based on the findings of pre-operative angiographies,

interventional treatment of the occlusion was deemed infeasible in 97 cases and patients received an operative bypass revascularization. Therefore, the study includes 97 tibial grafts in 89 patients (male, 64.9%; female, 35.1%; median age, 73 years; range, 50e90 years). Indication was Rutherford IV in 24.7% and Rutherford V/VI in 75.3%. Of the 97 cases 56 received an autologous vein graft (VeinGroup) and 41 received a HePTFE graft (HePTFE-Group). All HePTFE grafts were 6 mm ring enforced Gore-Propaten grafts and were only used if patients did not have an adequate vein. We did not use vein patches at the distal anastomosis site. Every patient underwent a pre-operative ultrasound imaging of his upper and lower extremities. A vein was deemed suitable if the diameter was a minimum of 3 mm and if no more than 2 vein segments were needed to obtain sufficient graft length. In the majority of autologous vein bypasses we used the great saphenous vein (92.9%); we used arm veins and small saphenous veins whenever the great saphenous vein was not available. Patient characteristics and risk factors are shown in Table 1. Bypass characteristics are shown in Table 2. 5 of the HePTFE bypasses and 1 of the vein bypasses were done as bridge bypasses and were connected to two tibial outflow vessels. Follow-up examinations were scheduled every 6 months at first and then every 12 months (if two consecutive follow-up Duplex scans had shown good bypass blood flow). We evaluated wound healing and pain and did a Duplex scan to evaluate bypass patency. We deemed the bypass occluded whenever we were not able to detect a duplex signal that would have indicated bypass perfusion. Patients who had

Table 1 e Patient characteristics and indications.

Median age Men Coronary artery disease Hypertension Renal insufficiency Dialysis Smokers/Ex-smokers Rest pain Ulcer/Gangrene Additional minor amputation Bridge bypass Infrapopliteal vessel run-off 1 vessel run-off 2 vessel run-off 3 vessel run-off Malleolar vessel run-off 1 vessel run-off 2 vessel run-off Prior operation Prior bypasses Prior thromboendarterectomy CFA Prior thromboendarterectomy TFT Prior embolectomy Prior PTA Prior lytic therapy

All (n ¼ 97)

Vein (n ¼ 56)

HePTFE (n ¼ 41)

P

73 (50e90) 63 (64.9%) 44 (45.4%) 91 (93.8%) 50 (51.5%) 8 (8.2%) 28 (28.9%) 24 (24.7%) 73 (75.3%) 11 (11.3%) 6 (6.2%)

73 (50e88) 38 (67.9%) 22 (39.3%) 53 (94.6%) 24 (42.9%) 2 (3.6%) 16 (28.6%) 17 (30.4%) 39 (69.6%) 5 (8.9%) 1(1.8%)

73 (52e90) 25 (61.0%) 22 (53.7%) 38 (92.7%) 26 (63.4%) 6 (14.6%) 12 (29.3%) 7 (17.1%) 34 (82.9%) 6 (14.6%) 5(12.2%)

0.751 0.313 0.115 0.504 0.036* 0.057 0.558 0.103 0.103 0.228 0.080

80 (82.5%) 17 (17.5%) 0

47 (83.9%) 9 (16.1%) 0

33 (80.5%) 8 (19.5%) 0

0.429 0.429

86 (88.7%) 11 (11.3%) 37 (38.1%) 29 (29.9%) 3 (3.1%) 3 (3.1%) 2 (2.1%) 30 (30.9%) 6 (6.2%)

51 (91.1%) 5 (8.9%) 19 (33.9%) 13 (23.2%) 2 (3.6%) 2 (3.6%) 2 (3.6%) 18 (32.1%) 3 (5.4%)

35 (85.4%) 6 (14.6%) 18 (43.9%) 16 (39.0%) 1 (2.4%) 1 (2.4%) 0 12 (29.3%) 3 (7.3%)

0.288 0.288 0.215 0.073 0.616 0.616 0.331 0.470 0.504

CFA ¼ Common femoral artery; TFT ¼ Tibial-fibular trunk. (*) ¼ significant.

Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

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Table 2 e Bypass characteristics. Inflow level (SB þ BB) External iliac artery Common femoral artery Distal superficial femoral Above-knee popliteal Below-knee popliteal Outflow level SB Anterior tibial Posterior tibial Fibular artery Tibial-fibular trunk Outflow level BB Anterior tibial Posterior tibial Fibular artery Grafts GSV SSV Arm vein Composite arm vein þ SSV

All

Vein

HePTFE

All (n ¼ 97) 2 (2.1%) 54 (55.7%) 11 (11.3%) 21 (21.6%) 9 (9.3%) All (n ¼ 91) 40 (44.0%) 17 (18.7%) 23 (25.3%) 11 (12.1%) All (n ¼ 6) 6 (100.0%) 1 (16.7%) 5 (83.3%)

Vein (n ¼ 56) 0 18 (32.1%) 9 (16.1%) 20 (35.7%) 9 (16.1%) Vein (n ¼ 55) 15 (27.3%) 12 (21.8%) 20 (36.4%) 8 (14.5%) Vein (n ¼ 1) 1 (100.0%) 0 1 (100.0%)

HePTFE (n ¼ 41) 2 (4.9%) 36 (87.8%) 2 (4.9%) 1 (2.4%) 0 HePTFE (n ¼ 36) 25 (69.4%) 5 (13.9%) 3 (8.3%) 3 (8.3%) HePTFE (n ¼ 5) 5 (100.0%) 1 (20.0%) 4 (80.0%)

P 0.176 0.001* 0.079 0.000* 0.005* 0.000* 0.253 0.002* 0.293 e e e

49 (87.5%) 3 (5.4%) 3 (5.4%) 1 (1.8%)

(*) ¼ significant.

received their last duplex scan more than 6 months prior to the end of the study were called in for another follow-up duplex. We achieved a complete follow-up with no patients lost during the period of our study. Patients received anticoagulation treatment in accordance with their pre-existing conditions, contraindications and bypass graft. We opted for Phenprocoumon þ aspirin whenever possible. Due to socioeconomic factors or contraindications to Phenprocoumon, some received aspirin þ clopidogrel. 57.3% of patients were on statins for hypercholesterolemia. Study endpoints were primary and secondary patency, limb salvage, and survival at 1 and 2 years postoperatively. Primary patency was defined as period between bypass surgery and first graft occlusion and secondary patency was defined as period between bypass surgery and second occlusion of the graft. We used SPSS 15 to do statistical analysis, as well as KaplaneMeier life table method to evaluate primary and secondary graft patency, limb salvage and patient survival. Non-parametric ManteleCox LogeRank test was used for comparisons between the groups. Our data had a non-normal distribution; therefore, non eparametric analysis was chosen. X2 test and Fisher's exact test were used to compare patient demographics and bypass characteristics. P < .05 was considered to be statistically significant.

Results Patient characteristics, anticoagulation, morbidity and mortality. There were no significant differences in risk factors between the groups, except for renal insufficiency. 6 patients in the HePTFE-Group were on dialysis vs. 2 patients in the VeinGroup (P ¼ .057). Indications and prior revascularization procedures were similar in both groups (Table 1).

9 Patient died within the first 30 day postoperatively, 4 in the Vein-Group and 5 in the HePTFE-Group. Cause of death was myocardial infarction in 6 cases, renal failure in 2 cases and pulmonary failure in 1 case. There were no significant differences between the groups (Table 3). There was no significant difference in anticoagulation/ antiplatelet treatment between the two groups. 26.8% of patients in the HePTFE-Group received Phenprocoumon vs. 33.9% in the Vein-Group (P ¼ .301). 53.7% received Phenprocoumon þ aspirin vs. 46.6% (P ¼ .309). Clopidogrel þ aspirin were given to 19.5% in the HePTFEGroup vs. 19.6% in the Vein-Group (P ¼ .599). Primary and secondary patency rates. At 1 year overall primary patency was 74.8% and secondary patency was 74.9%. At 2 years overall primary patency was 62.8% and secondary patency was 68.3%. The comparison between HePTFE- and Vein-Group showed significantly different patency rates. Primary patency at 1 year was 61.7% in the HePTFE-Group vs. 79.5% in the Vein-Group (P ¼ .004) and 39.3% vs. 78.5% at 2 years (P ¼ .003) (Fig. 1). Secondary patency at 1 year was 68.5% vs. 83.7% (P ¼ .002) and 47.4% vs. 81.9% at 2 years (P ¼ .002) (Fig. 2).

Table 3 e Morbidity and mortality data. All (n ¼ 7) 30-day mortality Myocardial infarction Renal failure Respiratory failure 30-day graft failure 30-day major amputation

Vein (n ¼ 56)

HePTFE (n ¼ 41)

P

9 (9.3%) 6 (6.2%)

4 (7.1%) 4 (7.1%)

5 (12.2%) 2 (4.8%)

0.308 0.205

2 (2.1%) 1 (1.0%) 11 (11.3%) 4 (4.1%)

1 1 5 3

1 (2.4%) 0 6 (14.6%) 1 (2.4%)

0.669 0.577 0.288 0.434

(1.8%) (1.8%) (8.9%) (5.4%)

Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

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100 90 80 70

Percent

60 50 40 30 20 10

Vein HePTFE

0 0,00

6,00

12,00

18,00

24,00

Months Number at risk Vein 56 HePTFE 41

25 (SE 0.06) 12 (SE 0.09)

18 (SE 0.06) 7 (SE 0.10)

Figure 1 e Primary Patency Vein-group and HePTFE-group (P ¼ .004, 1 year; P ¼ .003, 2 years); SE ¼ Standard error.

Limb salvage and survival rates. Overall limb salvage was 90.7% at 1 year and 84.1% at 2 years. The overall survival rates were 75.9% and 63.2%, respectively. There were no significant differences in limb salvage and survival rates between the groups. Limb salvage at 1 year was

91.2% vs. 90.3% (P ¼ .079) and 79.3% vs. 87.4% at 2 years (P ¼ .073) (Fig. 3). Survival at 1 year was 73.0% vs. 78.1% (P ¼ .690) and 64.6% vs. 62.9% at 2 years (P ¼ .593) (Fig. 4). The 30-day major amputation rate was 5.4% in the Vein-Group and 2.4% in the HePTFE-Group (P ¼ .434) (Table 3).

100 90 80 70

Percent

60 50 40 30 20 10

Vein HePTFE

0 0

6

12

18

24

Months Number at risk Vein 56 HePTFE 41

29 (SE 0.06) 14 (SE 0.09)

22 (SE 0.06) 9 (SE 0.10)

Figure 2 e Secondary Patency Vein-group and HePTFE-group (P ¼ .002, 1 year; P ¼ .001, 2 years); SE ¼ Standard error. Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

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100 90 80 70

Percent

60 50 40 30 20 10

Vein HePTFE

0 0

6

12

18

24

Months Number at risk Vein 56 HePTFE 41

35 (SE 0.04) 25 (SE 0.05)

24 (SE 0.05) 16 (SE 0.08)

Figure 3 e Limb salvage Vein-group and HePTFE-group (P ¼ .079, 1 year; P ¼ .064, 2 years), SE ¼ Standard error.

Discussion The goal of our study was to analyze the outcome of tibial and peroneal bypasses in diabetics. The influence of diabetes on bypass patency rates and limb salvage is controversially discussed in literature.2e5 Data on tibial and peroneal bypasses is rare. Autologous vein is the preferred graft material. In the

absence of an adequate vein, prosthetic grafts are being used. The outcome of HePTFE grafts in diabetics in this context remains unclear. Our study found significant differences in patency between the Vein- and HePTFE-Group at 1 and 2 years. Diabetics with venous grafts have significantly better primary and secondary patency rates than diabetics with HePTFE grafts. Limb salvage and survival rates do not differ significantly. These results

100 90 80 70

Percent

60 50 40 30 20 10

Vein HePTFE

0 0

6

12

18

24

Months Number at risk Vein 56 HePTFE 41

37 (SE 0.06) 26 (SE 0.07)

27 (SE 0.07) 17 (SE 0.08)

Figure 4 e Survival Vein-Group and HePTFE-group (P ¼ .690, 1 year; P ¼ .499, 2 years), SE ¼ Standard error. Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

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suggest that diabetics with HePTFE bypass will not face higher limb loss rates than venous graft recipients. This conclusion is further supported by the results of Dorigo et al., who report in one of their studies similar results for diabetics. They describe better primary patency rates for venous grafts (63.5% vs. 46.3% for HePTFE at 4 years; P ¼ .03) and no significant differences between grafts in limb salvage and survival.4 However, Dorigo's study included all kinds of below-knee bypasses. A recent study by Jung et al. analyzed the outcome of infrainguinal bypass surgery in a purely diabetic patient cohort. They report a 1-year limb salvage of 92.1%, which is slightly higher than our overall limb salvage of 90.7% at 1 year.5 Their 3-year limb salvage of 88.9% is higher than our overall 3-year limb salvage of 74.4%. Jung et al. used venous and prosthetic grafts but their report lacks information on what kind of prosthetic bypass material they used. Maybe their higher 3-year limb salvage rate could be explained by a higher percentage of vein graft recipients in their patient cohort, since venous bypasses generally tend to achieve better outcomes than prosthetic graft bypasses.6,7 Also their report included both above- and below-knee bypasses. Woelfle et al. compared the outcome of infrainguinal bypass surgery in diabetics and non-diabetics. They report a 1year limb salvage of 85% and a 1-year primary patency of 66%.2 One possible reason why we obtained slightly better results is that we used HePTFE grafts instead of the PTFE grafts used by Woelfle. Multiple studies have shown that HePTFE grafts have good long-term outcomes and provide better results than regular PTFE grafts.8e10 Neither Jung et al. nor Woelfle et al. did a subgroup analysis to contrast the outcomes of vein graft and prosthetic graft recipients. Ballotta et al. published a prospective study in which they analyzed the outcome of lower extremity arterial reconstruction in patients with critical limb ischemia. They specifically compared the results of infrainguinal bypass surgery in diabetics and non-diabetics. Ballotta concluded that diabetics and non-diabetics do not have significantly different results in patency, limb salvage or survival.11 They did not find a relation between the type of graft material and patency or limb salvage rates. It has been reported that dialysis dependence is a negative prognostic factor on the outcome of bypass surgery in terms of amputation-free survival and survival.12 Further, end-stage renal disease has been described to be a relevant factor in a decreased 1-year patency.13 Even though the difference of dialysis dependence in the two groups did not reach the level of statistical significance, the outcome of the HePTFE-Group might have been slightly impaired by the higher incidence of dialysis in the group. Our patients received Phenprocoumon þ aspirin whenever possible. This strategy is supported by a study from Suckow et al. that indicated that prosthetic bypasses tend to have better patency rates with warfarin þ aspirin than with clopidogrel þ aspirin (even though the level of statistical significance was not reached).14 Nearly 60% of our cohort was on statin therapy. In a further recent study, Suckow et al. reported a positive impact of statin therapy on the 5-year survival; however, the one year graft occlusion and major amputation rate for infrainguinal bypasses were not influenced by it.15

We did not use vein patches at the distal anastomosis site of our HePTFE bypasses. Even though multiple studies suggest that vein patches improve patency rates of PTFE bypasses due to factors such as less myointimal hyperplasia and lower thrombogenicity,16,17 there are no conclusive studies on their value in heparin-bonded PTFE bypasses. We cannot rule out, however, that even better patency results could have been achieved if distal vein patches had been used in our HePTFE bypasses. This strengthens our conclusion that HePTFE bypasses are a viable option in lack of an adequate vein. Our study has several limitations. It is a retrospective study with a relatively small patient cohort. We did not gather HbA1c levels to distinguish between potentially well-treated diabetics and not well-treated ones, which might have had effects on limb salvage and survival rates. Moreover, monitoring time was limited and long-term findings could not be established. Nevertheless, our study showed that in the absence of a suitable vein, HePTFE grafts are a viable alternative in diabetics with CLI. They do not face significantly higher limb loss rates than those with venous bypass. However, our findings also show that vein grafts do achieve significantly better patency rates and that they also tend to achieve better limb salvage and survival rates, although without reaching significance. Therefore vein grafts should continue to be first-choice graft material. Further prospective studies are needed to confirm our findings and to establish long-term results.

Conclusion Our study shows that in the absence of an adequate vein, tibial and peroneal HePTFE bypasses are a viable option for diabetics with CLI.

Acknowledgements None.

references

1. Minar E. Critical limb ischaemia. Hamostaseologie 2009 Jan;29(1):102e9. € lfle KD, Bruijnen H, Loeprecht H, Ru¨menapf G, 2. Wo Schweiger H, Grabitz K, et al. Graft patency and clinical outcome of femorodistal arterial reconstruction in diabetic and non-diabetic patients: result of a multicenter comparative analysis. Eur J Vasc Endovasc Surg 2003;25(3):229e34. € m L, 3. Malmstedt J, Leander K, Wahlberg E, Karlstro Alfredsson L, Swedenborg J. Outcome after leg bypass surgery for critical limb inschemia is poor in patients with diabetes: a population-based cohort study. Diabetes Care 2008;31(5):887e92. 4. Dorigo W, Pulli R, Castelli P, Dorrucci V, Ferilli F, De Blasis G, et al. A multicenter comparison between autologous saphenous vein and heparin-bonded expanded polytetrafluorethylene (ePTFE) graft in the treatment of

Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005

t h e s u r g e o n x x x ( 2 0 1 5 ) 1 e7

5.

6.

7.

8.

9.

10.

11.

critical limb ischemia in diabetics. J Vasc Surg 2011;54(5):1332e8. Jung H, Cho J, Kim HK, Kim J, Huh S. Long-term outcomes of infrainguinal bypass surgery for patients with diabetes mellitus and tissue loss. Ann Surg Treat Res 2015;88(1):35e40. Klinkert P, Post PN, Breslau PJ, van Bockel JH. Saphenous vein versus PTFE for above-knee femoropopliteal bypass. A review of the literature. Eur J Vasc Endovasc Surg 2004;27(4):357e62. Conte MS. Challenges of distal bypass surgery in patients with diabetes: patient selection, techniques, and outcomes. J Vasc Surg 2010;52:96Se103S. Lindholt JS, Gottschalksen B, Johannesen N, Dueholm D, Ravn H, Christensen ED, et al. The Skandinavian Propaten ® trial e 1-year patency of PTFE vascular prostheses with heparin-bonded luminal surfaces compared to ordinary pure PTFE vascular prostheses e a randomised clinical controlled multi-centre trial. Eur J Vasc Endovasc Surg 2011;41(5):668e73. Kirkwood ML, Wang GJ, Jackson BM, Golden MA, Fairman RM, Woo EY. Lower limb revascularisation for PAD using heparincoated PTFE conduit. Vasc Endovascular Surg 2011;45(4):329e34. € sel-Sadee H, Alefelder C. Heparin bonded expanded Lo polytetrafluoroethylene graft for infragenicular bypass: fiveyear results. J Cardiovasc Surg 2009;50(3):339e43. Ballotta E, Toniato A, Piatto G, Mazzalai F, Da Giau G. Lower extremity arterial reconstruction for critical limb ischemia in diabetes. J Vasc Surg 2014;59(3):708e19.

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12. Kodama A, Sugimoto M, Kuma S, Okazaki J, Mill S, Komori K. Clinical outcomes after infrainguinal bypass grafting for critical limb ischaemia in patients with dialysis-dependent end-stage renal failure. Eur J Vasc Endovasc Surg 2014 Dec;48(6):695e702. 13. Neville RF, Capone A, Amdur R, Lidsky M, Babrowicz J, Sidawy AN. A comparison of tibial artery bypass performed with heparin-bonded expanded polytetrafluoroethylene and great saphenous vein to treat critical limb ischemia. J Vasc Surg 2012;56(4):1008e14. 14. Suckow BD, Kraiss LW, Stone DH, Schanzer A, Bertges DJ, Baril DT, et al. Comparison of graft patency, limb salvage, and antithrombotic therapy between prosthetic and autogenous below-knee bypass for critical limb ischemia. Ann Vasc Surg 2013 Nov;27(8):1134e45. 15. Suckow BD, Kraiss LW, Schanzer A, Stone DH, Kalish J, DeMartino RR, et al. Statin therapy after infrainguinal bypass surgery for critical limb ischemia is associated with improved 5-year survival. J Vasc Surg 2015;61(1):126e33. 16. Flis V, Pavlovic M, Miksic K. The value of adjunctive vein patches to improve the outcome of femorodistal polytetrafluoroethylene bypass grafts. Wien Klin Wochenschr 2001;113(Suppl 3):5e10. 17. Neville RF, Lidsky M, Capone A, Babrowicz J, Rahbar R, Sidawy AN. An expanded series of distal bypass using the distal vein patch technique to improve prosthetic graft performance in critical limb ischemia. Eur J Vasc Endovasc Surg 2012 Aug;44(2):177e82.

Please cite this article in press as: Hock C, et al., A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia, The Surgeon (2015), http://dx.doi.org/10.1016/j.surge.2015.06.005