Impact of increasing comorbidity on infrainguinal reconstruction: a 20-year perspective

Progression of chronic kidney disease after non-cardiac surgery: A retrospective cohort study

BACKGROUND

Chronic-kidney-disease (CKD) is prevalent among adults undergoing noncardiac surgery, with surgery-related factors potentially worsening CKD or triggering acute kidney injury (AKI). We hypothesized that CKD patients experience more kidney function decline within one to two years post-surgery than those without CKD, particularly if they develop AKI.

METHODS

We conducted a single-center retrospective cohort study, including noncardiac surgery patients with documented creatinine preoperative and between 1 and 2 years after surgery. The primary outcome was long-term course of kidney function, defined as the change in estimated glomerular filtration rate (eGFR) in mL/min/1.73m2.

RESULTS

Of 58,175 included cases, 17 % had preoperative CKD. Mean eGFR changed from 90.1 ± 16.7 to 92.0 ± 18.8 in non-CKD patients and from 45.6 ± 11.9 to 55.6 ± 20.1 in patients with CKD, with an estimated difference in means of 8.9 (95 % CI: 8.5, 9.3; P < 0.0001). There was a significant interaction between CKD-dependent eGFR change from baseline to follow-up and postoperative AKI (P = 0.001). For cases with preoperative CKD, eGFR increase from baseline to follow-up was 11.7 ± 18.0 with no AKI, 7.7 ± 17.9 with AKI stage 1, 2.4 ± 15.0 with AKI stage 2, and 7.3 ± 25.8 with AKI stage 3. For non-CKD patients, eGFR increased from baseline by 2.3 ± 13.7 with no AKI but decreased by 5.5 ± 19.0 with AKI stage 1, 7.7 ± 21.8 with AKI stage 2, and 9.3 ± 21.3 with AKI stage 3.

CONCLUSIONS

Contrary to expectations, patients with preoperative CKD experienced a significant improvement in eGFR postoperatively. Patients without CKD exhibited minimal change. Postoperative AKI negated the eGFR improvement in CKD patients and exacerbated the decline in non-CKD patients.

Drug-Coated Balloons in Autologous Vein Peripheral-Distal Bypass Graft Maintenance: Advancements and Potential Impact

INTRODUCTION

Initial surgical revascularization has a recognized primary role in patients with critical limb-threatening ischemia with a high-quality great saphenous vein for conduit. However, approximately one-third of lower extremity vein grafts develop lesions threatening graft patency. Traditional treatments have limitations, highlighting the need for innovative solutions. The advantage of drug-coated balloons (DCBs) in treating native femoropopliteal occlusive disease is well established for its anti-restenotic features. This study evaluates the use of DCBs in maintaining the patency of autologous vein infrainguinal bypass grafts.

METHODS

This retrospective multicenter cohort study included consecutive patients who underwent DCB angioplasty of infrainguinal bypass vein graft stenoses from January 2010 to December 2022 in 4 tertiary Vascular Surgery referral Centers. The primary endpoints were assisted primary patency rate, amputation, and death. All endpoints were assessed at baseline, at 1, 3, and 6 months, and every 6 months after the procedure. Follow-up was mainly performed via duplex ultrasound, by hand of an experienced independent operator.

RESULTS

In total, 296 patients received an endovascular procedure for primary patency loss of a pre-existing infrainguinal saphenous vein bypass graft. Of these, 86 cases (29%) were treated with a paclitaxel-coated balloon. The mean age of patients was 72 (67-75) years, most being males (62%, n=53). The median time from the primary revascularization to reintervention with DCB was 2.58 (95% confidence interval [CI]: 2.31-3.10) years. The DCB angioplasty involved the proximal anastomosis in 20%, the graft in 51%, the distal anastomosis in 33%, and the outflow region in 28% of cases. During a median follow-up of 5 years (3.93-7.01), a 69% assisted primary patency rate was recorded. Limb salvage was achieved in 100% of cases at 1 year and in 90% of cases at 3 years. Only 6 cases of major amputation were recorded in a median follow-up time of 10 years. Overall survival reached 84% at 5 years, calculated on a median follow-up of 9.4 (95% CI: 8.7-10.1) years.

CONCLUSION

Results suggest that DCBs may have a transformative impact on vascular care, reducing the need for repeated reinterventions, and thus improving the quality of life for patients with peripheral bypass grafts.

CLINICAL IMPACT

This study proposes a groundbreaking shift in the management of lower extremity vein graft lesions. By demonstrating the efficacy of drug-coated balloons (DCBs) in maintaining patency of infrainguinal vein bypass grafts, it offers clinicians a novel strategy to address a significant clinical challenge. Unlike traditional treatments with their limitations, DCBs present a promising alternative, potentially reducing the burden of repeated reinterventions. This innovation signifies a tangible improvement in patient outcomes, promising enhanced limb salvage rates and overall survival, thereby revolutionizing vascular care and enhancing the quality of life for individuals with peripheral bypass grafts.

Editor's Choice - Endovascular Versus Surgical Treatment for All Comer Patients With Prosthetic Bypass Graft Occlusion: The Multicentre ENSUPRO Study

OBJECTIVE

Bypass surgery plays a key role in complex lower limb lesions. However, there is a lack of evidence regarding the management of symptomatic prosthetic bypass graft (PBG) occlusion. This study aimed to report outcomes following open, hybrid, or endovascular management of patients presenting with symptomatic PBG occlusion.

METHODS

A multicentre, retrospective cohort study was conducted, including patients presenting with PBG occlusion between January 2014 and December 2021 from 18 centres. It assessed the comparative value of treatment strategies, including (1) recanalisation of native vessels, (2) endovascular treatment of the failed PBG, (3) hybrid treatment, and (4) open surgery. The primary outcome measure was amputation free survival (AFS, time to major amputation and or death), whereas all cause mortality, major amputation, PBG re-occlusion, target lesion revascularisation (TLR), and Rutherford category (RC) improvement during follow up were considered as secondary endpoints.

RESULTS

Of 260 patients with occluded PBGs, 108 (41.5%) were treated endovascularly (24 [22.2%] by recanalisation of native vessels and 84 [77.7%] by PBG re-opening), 57 (21.9%) underwent hybrid revascularisation, and 58 (22.3%) had surgery. In addition, 27 (10.4%) were treated conservatively and 10 (3.8%) received systemic thrombolysis. With a median follow up of 1.4 (0.6 - 3.0) years, AFS was 95.5%, 76.4%, 45.5%, and 37.1%, respectively in Groups 1 - 4 (p = .007). Older age and non-endovascular treatment (HR 1.05 and 1.70; p < .01 for both) were independent predictors of poor AFS. Endovascular treatment was associated with lower rates of major amputation (p = .04), PBG re-occlusion (p < .001), and TLR (p = .037), and higher RC improvements (p < .001), whereas all cause mortality was comparable between treatment groups (p = .21).

CONCLUSION

Endovascular treatment is associated with higher rates of AFS and RC improvement and lower rates of PBG re-occlusion and TLR in patients with PBG occlusion.

Contemporary outcomes of open femoropopliteal bypass by autogenous vein graft in infra-inguinal arterial occlusive disease

BACKGROUND

Although the majority of patients presenting with symptomatic peripheral arterial disease (PAD) are treated with the endovascular first approach, a significant number of these patients still require open bypass because of the extent of atherosclerotic burden or failure of the endovascular therapy. However, data available on the outcomes of femoropoliteal bypass in the contemporary era of PAD management is scarce. In this study, we evaluate real-world mid-term outcomes of femoropopliteal bypass for PAD.

METHODS

We identified all patients who underwent open femoropopliteal revascularization with autogenous vein conduits for PAD at one institution between January 2012 and December 2017. Main endpoints included primary patency, amputation-free survival, overall survival and limb salvage at two years. Outcomes were defined per the Society for Vascular Surgery standards. Descriptive statistics were performed using univariable analyses including mean and standard deviation for continuous variables and frequency and percentage for categorical variables. Event-free survival rates were estimated using Kaplan-Meier (KM) methods.

RESULTS

There were 129 patients who received autogenous vein grafts. Median follow-up was 19 months (IQR 11-26). Patients were predominantly male (59.7%), white (72.9%) with a mean age of 65±11 years. The indications for surgery were disabling claudication in 36.4% of patients (N=47) and chronic limb threatening ischemia (CLTI) in 63.6% (N=82). Most patients had TASC C or D lesions (N=81, 62.8%). Seventeen cases (16.3%) were redo bypasses. Arm veins and spliced vein conduits were used in 12% and 7%, respectively. In 66% of procedures the distal anastomosis was below the knee. Primary patency estimates at 6 months, 1 year and 2 years were 81.3%, 68.6% and 59.2%, respectively. Amputation-free survival rates were 93.4%, 88% and 82.1% at 6 months, 1 year and 2 years, respectively. Limb salvage rates among patients with CLTI were 93.4%, 90.4% and 87.2% at 6 months, 1 year and 2 years, respectively. Overall survival was 97.5%, 92.1% and 87.8% at 6 months, 1 year and 2 years, respectively.

CONCLUSIONS

In this contemporary cohort of patients, femoropopliteal bypass showed lower patency than previously described. The fact that bypass surgery is performed on sicker patients with more extensive disease in the endovascular era might explain this discrepancy. However, our results demonstrated satisfactory patency and limb salvage rates and suggest that vein should always be used if available.

OUP accepted manuscript

Background

The relationship between anaesthetic technique and graft patency after open lower limb revascularization is unclear. The aim of this study was to evaluate the association between 30-day graft patency after elective infrainguinal bypass and anaesthetic technique (regional anaesthesia (RA, i.e. neuraxial and/or peripheral nerve blockade) compared with general anaesthesia (GA)).

Methods

Patients who underwent elective infrainguinal bypass in the 2014–2019 National Surgical Quality Improvement Program Vascular Procedure Targeted Lower Extremity Open data set were included. Excluded patients were those under 18 years old, those who did not receive RA or GA, and/or had an international normalized ratio of 1.5 of greater, a partial thromboplastin time more than 35 s, or a platelet count less than 80 × 10⁹/L. The primary outcome was primary graft patency without reintervention. The relationship between anaesthetic technique and patency was analysed with multivariable logistic regression.

Results

Included were 8893 patients with a mean(s.d.) age of 68(11) years and 31.5 per cent female. Within the cohort, 7.7 per cent (n = 688) patients received RA only, 90.4 per cent (n = 8039) GA only, and 1.9 per cent (n = 166) both GA and RA. In the RA-only group, 91.7 per cent (631 of 688) received neuraxial anaesthesia. The primary patency rate was 93.2 per cent (573 of 615) for RA only, and 91.5 per cent (6390 of 6983) for GA only (standardized mean difference, 0.063). RA was not associated with a higher rate of patency compared with GA (adjusted OR, 1.16; 95 per cent c.i., 0.83 to 1.63; P = 0.378).

Conclusion

There was no association between anaesthetic technique and 30-day graft patency after elective infrainguinal bypass surgery. Further prospective studies would be useful to study the impact of anaesthesia technique on important patient-centred outcomes such as long-term patency and non-home discharge.

Effect of Rivaroxaban and Aspirin in Patients with Peripheral Artery Disease Undergoing Surgical Revascularization: Insights from the VOYAGER PAD Trial

Background: Patients with peripheral artery disease (PAD) requiring lower extremity revascularization (LER) are at high risk of adverse limb and cardiovascular events. VOYAGER PAD demonstrated that rivaroxaban significantly reduced this risk. The efficacy and safety of rivaroxaban has not been described in patients who underwent surgical LER. Methods: The VOYAGER PAD trial randomized patients with PAD after surgical and endovascular LER to rivaroxaban 2.5mg twice daily plus aspirin or matching placebo plus aspirin and followed for a median of 28 months. The primary endpoint was a composite of acute limb ischemia, major vascular amputation, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety outcome was Thrombolysis in Myocardial Infarction (TIMI) major bleeding. International Society on Thrombosis and Haemostasis (ISTH) bleeding was a secondary safety outcome. All efficacy and safety outcomes were adjudicated by a blinded independent committee. Results: Of the 6564 randomized, 2185 (33%) underwent surgical LER and 4379 (67%) endovascular. Compared to placebo, rivaroxaban reduced the primary endpoint consistently regardless of LER method (p-interaction 0.43). Following surgical LER, the primary efficacy outcome occurred in 199 (18.4%) patients in the rivaroxaban group and 242 (22.0%) patients in the placebo group with a cumulative incidence at 3 years of 19.7% and 23.9%, respectively (HR 0.81, 95% CI 0.67 - 0.98; p=0.026). In the overall trial, TIMI major bleeding and ISTH major bleeding were increased with rivaroxaban. There was no heterogeneity for TIMI major bleeding (p-interaction 0.17) or ISTH major bleeding (p-interaction 0.73) based on LER approach. Following surgical LER, the principal safety outcome occurred in 11 (1.0%) patients in the rivaroxaban group and 13 (1.2%) patients in the placebo group; 3-year cumulative incidence 1.3% and 1.4% respectively (HR 0.88, 95% CI 0.39-1.95; p=0.75) Among surgical patients, the composite of fatal bleeding or intracranial hemorrhage (p=0.95) and postprocedural bleeding requiring intervention (p=0.93) were not significantly increased. Conclusions: The efficacy of rivaroxaban is associated with a benefit in surgical LER patients. While bleeding was increased with rivaroxaban plus aspirin, the incidence was low, with no significant increase in fatal bleeding, intracranial hemorrhage or postprocedural bleeds requiring intervention. Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT02504216.

Bifurcated bypass in severe chronic limb threatening ischaemia

OBJECTIVES

Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia.

METHODS

Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed.

RESULTS

Mean follow-up period was 25.1 months (range 2-72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford's class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%.

CONCLUSIONS

Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.

Long Term Outcomes of Endovascular Therapy for Failing Distal Bypass Vein Grafts

OBJECTIVE

Although distal bypass using vein has been established with acceptable outcomes for chronic limb threatening ischaemia (CLTI), the major issue affecting long term outcomes is vein graft disease. This study aimed to analyse the peri-procedural results and long term outcomes of endovascular therapy (EVT) for failing vein grafts after distal bypass.

METHODS

A retrospective analysis of 113 failing vein grafts (94 patients, 113 limbs) after distal bypass between 2009 and 2019 at the study hospital.

RESULTS

The mean age was 74 ± 9 years and 72% of the patients were men. Of the 113 grafts, 54 grafts (48%) were detected in asymptomatic patients, 41 grafts (36%) in patients with recurrent ulcer or gangrene, and 18 grafts (16%) in patients with rest pain. The failing grafts were treated by low pressure long inflation balloon angioplasty with a mean balloon size of 3.0 ± 0.8 mm. The mean procedural time was 60 ± 29 min and procedural success was 98% (111 grafts). During the mean follow up period of 34 months, EVT was performed a median frequency of two times (range 1-11 times). The primary and assisted primary patency of the EVT revised grafts were 41% and 80% at one year, 34% and 68% at three years, 31% and 58% at five years, respectively. Of 41 limbs with recurrent ulcer or gangrene, the wound healed in 34 limbs (85%). The complete healing rate was 71% at three months and 84% at 12 months. Eight patients required major amputation, and the freedom from major amputation rate was 96% at one year and 80% at five years.

CONCLUSION

Long term outcomes including patency, wound healing rate, and amputation free survival after EVT for failing vein grafts were acceptable. EVT could be a viable alternative to surgical revascularisation in patients with a failing distal bypass graft for CLTI.

Multivessel tibial revascularization does not improve outcomes in patients with critical limb ischemia

OBJECTIVE

Multivessel tibial revascularization for critical limb ischemia (CLI) remains controversial. The purpose of this study was to evaluate single vs multiple tibial vessel interventions in patients with multivessel tibial disease. We hypothesized that there would be no difference in amputation-free survival between the groups.

METHODS

Using the Vascular Quality Initiative registry, we reviewed patients undergoing lower extremity endovascular interventions involving the tibial arteries. Patients with CLI were included only if at least two tibial vessels were diseased and adequate perioperative data and clinical follow-up were available for review. The primary outcome was amputation-free survival.

RESULTS

There were 10,849 CLI patients with multivessel tibial disease evaluated from 2002 to 2017; 761 limbs had adequate data and follow-up available for review. Mean follow-up was 337 ± 62 days. Of these, 473 (62.1%) underwent successful single-vessel tibial intervention (group SV), whereas 288 (37.9%) underwent successful multivessel (two or more) intervention (group MV). Patients in group MV were younger (69.1 vs 73.2 years; P < .001), with higher tobacco use (29.5% vs 18.2%; P < .001). Group SV more commonly had concurrent femoral or popliteal inflow interventions (83.7% vs 78.1%; P = .05). Multivessel runoff on completion was significantly greater for group MV (99.9% vs 39.9%; P < .001). No differences were observed between group SV and group MV for major amputation (9.0% and 7.6%; P = .6), with similar amputation-free survival at 1 year (90.6% vs 92.9%; P = .372). In a multivariate Cox model, loss of patency was the only significant predictor of major amputation (hazard ratio, 5.36 [2.7-10.6]; P = .01). A subgroup analysis of 355 (46.6%) patients with tissue loss data showed that tissue loss before intervention was not predictive of future major amputation.

CONCLUSIONS

In the Vascular Quality Initiative registry, patients with CLI and occlusive disease involving multiple tibial vessels did not appear to have a limb salvage benefit from multiple tibial revascularization compared with single tibial revascularization.

Development of gene therapy with a cyclic adenosine monophosphate response element decoy oligodeoxynucleotide to prevent vascular intimal hyperplasia

OBJECTIVE

Intimal hyperplasia (IH) is the main cause of therapeutic failure after vascular and endovascular surgery. However, there is currently no targeted therapy for the treatment of IH. We recently reported that the inhibition of cyclic adenosine monophosphate response element (CRE) binding protein (CREB) activation is important in vein graft IH. We focused on a decoy oligodeoxynucleotide (ODN) therapeutic strategy for suppressing IH as a clinical application. The objective of this study was to confirm the therapeutic effect of a CRE decoy ODN in an animal model as a novel therapy for preventing intimal hyperplasia as the first step of the preclinical study of our strategy.

METHODS

We designed two phosphorothioate CREs and two scramble decoy ODNs and screened them using a CREB transcription assay to check their ability to bind to a CRE sequence. We chose a CRE decoy ODN with high first-binding ability and transfected it into vascular smooth muscle cells (VSMCs) in vitro. Proliferation and migration were assessed using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assays and modified Boyden chamber assays. We examined CRE activity using a luciferase reporter gene assay. We assessed the expression of messenger RNAs by quantitative real-time polymerase chain reaction. In a wire-injury mouse model (C57BL6, n = 6), CRE decoy ODN was transfected into the injured vessel wall using an ultrasound-sonoporation method in vivo. Mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) and four and a half LIM domains 5 (FHL5) expression of pregrafting vein remnants were assessed by immunohistologic analyses.

RESULTS

Compared with scramble decoy ODN, the selected CRE decoy ODN could significantly decrease CRE activity (mean ± standard error of the mean: 0.20 ± 0.03 vs 1.00 ± 0.16, n = 6; P < .05) as shown by a luciferase reporter gene assay, VSMC proliferation (0.73 ± 0.04 vs 0.89 ± 0.02, n = 6; P < .05) and migration (96.4 ± 6.1 vs 311.4 ± 19.1 migrated VSMCs/well, n = 6; P < .05) after 24-hour transfection. The CRE decoy ODN significantly suppressed the formation of IH at injured vessel walls in an animal model, as analyzed by pathologic staining (0.20 ± 0.02 vs 0.56 ± 0.08, area of the intima/area of the artery vs the control after 21 days' transfection, n = 6; P < .05). Furthermore, MAPKAPK3 and FHL5, which are CREB activators, were significantly expressed in pregrafting vein remnants in diabetes mellitus patients.

CONCLUSIONS

CREB-CRE signaling is an important mechanism of IH formation, and CRE decoy therapy can help preventing IH. This study is the first part of the preclinical study of our strategy.

Angioplasty versus stenting for infrapopliteal arterial lesions in chronic limb-threatening ischaemia

BACKGROUND

Chronic limb-threatening ischaemia (CLTI) is a manifestation of peripheral arterial disease (PAD) that includes chronic ischaemic rest pain or ischaemic skin lesions, ulcers, or gangrene for longer than two weeks. The severity of the disease depends on the extent of arterial stenosis and the availability of collateral circulation. Treatment for CLTI aims to relieve ischaemic pain, heal ischaemic ulcers, prevent limb loss, improve quality of life, and prolong survival. CLTI due to occlusive disease in the infrapopliteal arterial circulation (below-knee circulation) can be treated via an endovascular technique by a balloon opening the narrowed vessel, so called angioplasty, with or without the additional deployment of a scaffold made of metal alloy or other material, so called stenting. Endovascular interventions in the infrapopliteal vasculature may improve symptoms in patients with CLTI by re-establishing in-line blood flow to the foot. Controversy remains as to whether a balloon should be used alone to open the vessel, or whether a stent should also be deployed.

OBJECTIVES

To determine the efficacy and safety of percutaneous transluminal angioplasty (PTA) alone versus PTA with stenting of infrapopliteal arterial lesions (anterior tibial artery, posterior tibial artery, fibular artery (formerly known as peroneal artery), and common tibioperoneal trunk) for patients with chronic limb-threatening ischaemia (CLTI).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, as well as World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 25 June 2018. We applied no language restrictions.

SELECTION CRITERIA

We planned to include randomised or quasi-randomised controlled trials comparing PTA versus PTA with a stent and including patients aged 18 years or over with CLTI. We defined CLTI as Fontaine stage III (ischaemic rest pain) and IV (ischaemic ulcers or gangrene) or consistent with Rutherford category 4 (ischaemic rest pain), 5 (minor tissue loss), and 6 (major tissue loss), with stenotic (> 50% luminal loss) or occluded infrapopliteal artery, including tibiofibular trunk, anterior tibial artery, posterior tibial artery, and fibular artery. We included all types of stents irrespective of design (e.g. bare-metal, drug-eluting, bio-absorbable).

DATA COLLECTION AND ANALYSIS

Two review authors (CC-TH and GNCK) independently selected suitable trials, assessed trial quality, and extracted data. An additional third review author (MLvD) assessed trial quality and, when necessary, acted as arbiter for study selection and data extraction. Outcomes included technical success of the procedure, procedural complications, patency, major amputation, and mortality. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We included in the review seven trials with 542 participants. One trial randomised limbs to undergo PTA alone or PTA with stent placement, and the remaining studies randomised participants. Five trials with 476 participants show that the technical success rate was greater in the stent group than in the angioplasty group (odds ratio (OR) 3.00, 95% confidence interval (CI) 1.14 to 7.93; 476 lesions; 5 studies; I² = 23%). Meta-analysis of three eligible trials with 456 participants did not show a clear difference in short-term (within six months) patency between infrapopliteal arterial lesions treated with PTA and those treated with PTA and stenting (OR 0.88, 95% CI 0.37 to 2.11; 456 lesions; 3 studies; I² = 77%). Results also did not show clear differences between treatment groups in procedure complication rate (OR 0.87, 95% CI 0.01 to 53.60; 360 participants; 5 studies; I² = 85%), rate of major amputations at 12 months (OR 1.34, 95% CI 0.56 to 3.22; 306 participants; 4 studies; I² = 0%), and rate of mortality at 12 months (OR 0.71, 95% CI 0.43 to 1.17; 497 participants; 6 studies; I² = 0%). Heterogeneity between studies was high for the outcomes procedure complications and primary patency. The overall methodological quality of the trials included in this review was moderate due to selection and performance bias. Studies used different regimens for pretreatment and post-treatment antiplatelet/anticoagulant medication. We downgraded the certainty of the overall evidence for all outcomes by one level to moderate due to inconsistency of results across studies and large confidence intervals (small numbers of trials and participants).

AUTHORS' CONCLUSIONS

Trials show that the immediate technical success rate of restoring luminal patency is higher in the stent group but reveal no clear differences in short-term patency at six months between infrapopliteal arterial lesions treated with PTA with stenting versus those treated with PTA without stenting. We ascertained no clear differences between groups in periprocedural complications, major amputation, and mortality. However, use of different regimens for pretreatment and post-treatment antiplatelet/anticoagulant medication and the duration of its use within and between trials may have influenced the outcomes. Limited currently available data suggest that high-quality evidence is insufficient to show that PTA with stent insertion is superior to use of standard PTA alone without stenting for treatment of infrapopliteal arterial lesions. Further studies should standardise the use of antiplatelets/anticoagulants before and after the intervention to improve the comparability of the two treatments.

Drug-eluting stents are associated with improved outcomes for the treatment of infrainguinal bypass graft stenoses

BACKGROUND

Existing endovascular therapies for failing infrainguinal bypass grafts are associated with modest patency rates. The use of everolimus drug-eluting stents (eDESs) for endovascular bypass graft revision has not yet been reported. The objective of this study was to describe and to compare clinical outcomes of eDESs vs percutaneous cutting balloons (PCBs) vs percutaneous transluminal angioplasty (PTA) for the treatment of infrainguinal bypass graft stenoses.

METHODS

A multicenter, single-institution retrospective analysis of patients with infrainguinal bypass graft stenoses treated by endovascular intervention (August 2010-December 2017) was conducted. The primary study outcome was primary patency of the treated lesion. The secondary outcome was limb salvage. Outcomes are described overall and stratified by endovascular treatment modality using Kaplan-Meier curves and log-rank tests.

RESULTS

During the 7-year study period, 43 patients with 78 infrainguinal bypass stenoses were treated by endovascular intervention (eDES, 15; PCB, 23; PTA, 40). Mean age was 63.3 ± 1.7 years, 53.5% were male, and 55.8% were black. The majority of patients were diabetic (60.5%) with a history of smoking (74.4%), and nearly all (83.7%) had two or more comorbidities. Half (48.7%) of bypasses treated were femoral-popliteal bypasses, followed by popliteal-distal (25.6%) and femoral-tibial (25.6%) configurations. The location of revision was the proximal anastomosis in 37.2%, midbypass in 25.6%, and distal anastomosis in 37.2%. There were no significant differences in baseline characteristics, bypass configuration, or revision location between treatment groups (P ≥ .19). Technical success for endovascular bypass intervention was 100%. At 2 years after intervention, primary patency was significantly better for patients treated with eDES (81.8%) compared with PCB (54.7%) or PTA (33.2%; log-rank, P = .03). Limb salvage was achieved in 93.6% of patients, including 86.7%, 91.3%, and 97.5% for eDES, PCB, and PTA, respectively (P = .30).

CONCLUSIONS

This is the first study reporting the results of eDESs for the treatment of infrainguinal bypass graft stenoses. Use of eDESs for endovascular bypass graft revision not only is feasible but may have better primary patency than other endovascular therapies. These data suggest that eDESs may be considered a safe and efficacious endovascular technique in the armamentarium for treatment of infrainguinal bypass graft stenoses.

Gene Therapy for the Extension of Vein Graft Patency: A Review

The mainstay of treatment for long-segment small-vessel chronic occlusive disease not amenable to endovascular intervention remains surgical bypass grafting using autologous vein. The procedure is largely successful and the immediate operative results almost always favorable. However, the lifespan of a given vein graft is highly variable, and less than 50% will remain primarily patent after 5 years. The slow process of graft malfunction is a result of the vein's chronic maladaptive response to the systemic arterial environment, its primary component being the uncontrolled proliferation of vascular smooth muscle cells (SMCs). It has recently been suggested that this response might be attenuated through pre-implantation genetic modification of the vein, so-called gene therapy for the extension of vein graft patency. Gene therapy seems particularly well suited for the prevention or postponement of vein graft failure since: (1) the stimulation of SMC proliferation appears to largely be an early and transient process, matching the kinetics of current gene transfer technology; (2) most veins are relatively normal and free of disease at the time of bypass allowing for effective gene transfer using a variety of systems; and (3) the target tissue is directly accessible during operation because manipulation and irrigation of the vein is part of the normal workflow of the surgical procedure. This review briefly summarizes the current knowledge of the incidence and basic mechanisms of vein graft failure, the vector systems and molecular targets that have been proposed as possible pre-treatments, the results of experimental genetic modification of vein grafts, and the few available clinical studies of gene therapy for vascular proliferative disorders.

Obstructive Sleep Apnea and Vascular Diseases

Obstructive sleep apnea (OSA) affects a large proportion of adults, and is as an independent risk factor for cerebrovascular and cardiovascular disease. The repetitive airway obstruction that characterizes OSA results in intermittent hypoxia, intrathoracic pressure swings, and sleep fragmentation, which in turn lead to sympathetic activation, oxidative stress, inflammation, and endothelial dysfunction. This review outlines the associations between OSA and vascular diseases and describes basic mechanisms that may be responsible for this association, in both the micro- and macrocirculation. It also reports on interventional studies that aim to ameliorate OSA and thereby reduce vascular disease burden. © 2016 American Physiological Society. Compr Physiol 6:1519-1528, 2016.

Open surgical or endovascular revascularization for acute limb ischemia

Acute limb ischemia (ALI) is one of the most common vascular emergencies, with high risk for limb loss if it is not treated expediently. Endovascular therapy is less invasive and used increasingly because of patient factors that disfavor open surgery despite limited quality data to support its safety and efficacy. This evidence summary reviews literature from 1990 to 2014, comparing contemporary surgical and endovascular revascularization. Systematic review was performed with emphasis on acuity of presentation, study design, revascularization techniques, limb salvage and mortality rates, and complications. There were 2999 articles identified and 563 abstracts reviewed; 68 articles were reviewed fully and 26 critically appraised. Limb salvage, amputation-free survival, overall survival and mortality, and treatment complications were elucidated, including Medicare outcomes data. Risk factors for amputation and mortality were identified. Surgical or endovascular revascularization for ALI is achievable with acceptable limb salvage and amputation rates, which are not markedly different between the two modalities in the short term. Endovascular therapy and surgery are complementary rather than competing strategies for ALI. Further good-quality clinical trial data are needed to define longer term outcomes.

Autologous vein graft stenosis inhibited by orphan nuclear receptor Nur77-targeted siRNA

Neointimal hyperplasia plays an important role in autologous vein graft stenosis, and orphan receptor TR3/nur77 (Nur77) might play an essential role, but the mechanisms are still unclear. Here, we investigated the function of Nur77 in autologous vein graft stenosis. Rat vascular smooth muscle cell A7r5 was used for evaluating the function of Nur77 and screen siRNAs. Meanwhile, rat vein graft models were constructed for investigating the stenosis inhibition effects of Nur77-targeted siRNAs. The mRNA and protein levels of Nur77 were highly expressed in A7r5 cell, and could be significantly inhibited by the pre-designed siRNAs; the proliferation of A7r5 cell was also inhibited by the siRNAs. Furthermore, the intimal thickening in rat vein graft models was inhibited when knocking down the expression of Nur77 by siRNA. The results suggest that Nur77-targeted siRNA can inhibit autologous vein graft stenosis, Nur77 may play an important role in autologous vein graft stenosis, and Nur77 targeted siRNAs may be a therapy method for anti-stenosis of autologous vein graft.

The impact of chronic renal insufficiency on vascular surgery patient outcomes

Renal insufficiency is associated with an increased incidence of poor outcomes, including cardiovascular events and death, in the general population. Renal dysfunction appears to have a particularly negative impact in patients undergoing vascular surgery and endovascular therapy. Although the exact mechanism is unknown, increased levels of inflammatory and biochemical modulators associated with adverse cardiovascular outcomes, as well as endothelial dysfunction, appear to play a role in the association between renal insufficiency and adverse outcomes. Outcomes after the surgical and endovascular treatment of abdominal aortic aneurysms, carotid disease, and peripheral arterial disease are all negatively affected by renal insufficiency. Patients with renal dysfunction may warrant intervention for the treatment of critical limb ischemia and symptomatic carotid stenosis, given the comparatively worse outcomes associated with medical management. Open repair of aortic aneurysms and carotid intervention for asymptomatic disease in patients with severe renal dysfunction should be performed with significant caution, as the risks of repair may outweigh the benefits in this population. Further study is needed to better delineate the risks of medical management for these conditions in patients with coexisting severe renal dysfunction. Lastly, current guidelines for the management of vascular diseases, including objective performance goals for critical limb ischemia, are likely not applicable in patients with severe renal insufficiency.

Perivascular biodegradable microneedle cuff for reduction of neointima formation after vascular injury

Restenosis often occurs at the site of vascular grafting and may become fatal for patients. Restenosis at anastomosis sites is due to neointimal hyperplasia (NH) and difficult to treat with conventional treatments. Such abnormal growth of smooth muscle cells in tunica media of vascular tissue can be reduced by delivering anti-proliferation drugs such as paclitaxel (PTX) to the inner vascular layer. Drug eluting stents (DES) or drug eluting balloon (DEB) have been developed to treat such vascular diseases. However, they are less efficient in drug delivery due to the drug loss to blood stream and inadequate to be applied to re-stenotic area in the presence of stent or anastomosis sites. Recently, we have introduced microneedle cuff (MNC) as perivascular delivery devices to achieve high delivery efficiency to tunica media. In this study, we investigated in vivo microneedle insertion and efficacy in treating NH using a rabbit balloon injury model. Microneedle shape was optimized for reliable insertion into tunica media layer. Uniform distribution of PTX in tunica media delivered by MNC devices was also confirmed. Animal study demonstrated significant NH reduction by MNC treatments and much higher delivery efficiency than flat type devices.

Vein graft failure

After the creation of an autogenous lower extremity bypass graft, the vein must undergo a series of dynamic structural changes to stabilize the arterial hemodynamic forces. These changes, which are commonly referred to as remodeling, include an inflammatory response, the development of a neointima, matrix turnover, and cellular proliferation and apoptosis. The sum total of these processes results in dramatic alterations in the physical and biomechanical attributes of the arterialized vein. The most clinically obvious and easily measured of these is lumen remodeling of the graft. However, although somewhat less precise, wall thickness, matrix composition, and endothelial changes can be measured in vivo within the healing vein graft. Recent translational work has demonstrated the clinical relevance of remodeling as it relates to vein graft patency and the systemic factors influencing it. By correlating histologic and molecular changes in the vein, insights into potential therapeutic strategies to prevent bypass failure and areas for future investigation are explored.

Critical appraisal of surgical revascularization for critical limb ischemia

Peripheral artery disease is growing in global prevalence and is estimated to afflict between 8 and 12 million Americans. Its most severe form, critical limb ischemia (CLI), is associated with high rates of limb loss, morbidity, and mortality. Revascularization is the cornerstone of limb preservation in CLI, and has traditionally been accomplished with open surgical bypass. Advances in catheter-based technologies, coupled with their broad dissemination among specialists, have led to major shifts in practice patterns in CLI. There is scant high-quality evidence to guide surgical decision making in this arena, and market forces have exerted profound influences. Despite this, available data suggest that the expected outcomes for both endovascular and open surgery in CLI are strongly dependent on definable patient factors such as anatomic distribution of disease, vein quality, and comorbidities. Optimal patient selection is paramount for maximizing benefit with each technique. This review summarizes some of the existing data and suggests a selective approach to revascularization in CLI, which continues to rely on vein bypass surgery as a primary option in appropriately selected patients.

A single nucleotide polymorphism in the p27(Kip1) gene is associated with primary patency of lower extremity vein bypass grafts

OBJECTIVE

Factors responsible for the variability in outcomes after lower extremity vein bypass grafting (LEVBG) are poorly understood. Recent evidence has suggested that a single nucleotide polymorphism (SNP) in the promoter region of the p27(Kip1) gene, a cell-cycle regulator, is associated with coronary in-stent restenosis. We hypothesized an association with vein graft patency.

METHODS

This was a retrospective genetic association study nested within a prospective cohort of 204 patients from three referral centers undergoing LEVBG for claudication or critical ischemia. The main outcome measure was primary vein graft patency.

RESULTS

All patients were followed up for a minimum of 1 year with duplex graft surveillance (median follow-up, 893 days; interquartile range, 539-1315). Genomic DNA was isolated and SNP analysis for the p27(Kip1)-838C>A variants was performed. Allele frequencies were correlated with graft outcome using survival analysis and Cox proportional hazards modeling. The p27(Kip1)-838C>A allele frequencies observed were CA, 53%; CC, 30%; and AA, 17%, satisfying Hardy-Weinberg equilibrium. Race (P = .025) and history of coronary artery disease (P = .027) were different across the genotypes; all other baseline variables were similar. Primary graft patency was greater among patients with the -838AA genotype (75% AA vs 55% CA/CC at 3 years; P = .029). In a Cox proportional hazards model including age, sex, race, diabetes, critical limb ischemia, redo (vs primary) bypass, vein type, and baseline C-reactive protein level, the p27(Kip1)-838AA genotype was significantly associated with higher graft patency (hazard ratio for failure, 0.4; 95% confidence interval, 0.17-0.93). Genotype was also associated with early (0-1 month) changes in graft lumen diameter by ultrasound imaging.

CONCLUSIONS

These data suggest that the p27(Kip1)-838C>A SNP is associated with LEVBG patency and, together with previous reports, underscore a central role for p27(Kip1) in the generic response to vascular injury.

Thirty-day vein remodeling is predictive of midterm graft patency after lower extremity bypass

OBJECTIVE

Successful adaptation of a vein graft to an arterial environment is incompletely understood. We sought to investigate whether early vein graft remodeling is predictive of subsequent patency.

METHODS

A prospective longitudinal study was conducted of 67 patients undergoing lower extremity bypass with autogenous vein between February 2004 and April 2008. Preoperative blood samples were drawn for biomarkers. During the bypass operation, a 5-cm index segment of the graft was registered for serial lumen diameter measurements at 0, 1, 3, 6, 9, and 12 months using duplex ultrasound imaging. The imaging substudy analysis included patients with at least two ultrasound assessments.

RESULTS

Patients (55% male) were a median age of 70 years (interquartile range [IQR], 59-76 years), 40% had diabetes mellitus, 49% had critical limb ischemia, 75% were taking a statin, and 91% were taking an antiplatelet medication. Median follow-up was 32 months (IQR, 15-47 months). The median baseline high-sensitivity C-reactive protein level (hsCRP) was 3.2 mg/L (IQR, 1.4-9.7 mg/L). The average intraoperative, postimplantation vein lumen diameter was 3.9±1.0 mm, increasing to 4.7±1.1 mm at 1 month, an average 24%±27% change per patient. By 3 months, the average lumen diameter was 5.1±1.6 mm, with little subsequent change observed to 12 months. Nonwhite race, baseline hsCRP ≥5 mg/L, statin use, and initial lumen diameter were significantly associated with early (0- to 1-month) vein remodeling in a multivariable regression model. The primary patency rate for the cohort was 60%±6.3% at 2 years. Initial lumen diameter of the index segment was not associated with primary patency, whereas larger lumen diameter achieved at 1 month (≥5.1 mm) was positively associated with primary patency (log-rank, P=.03). Early (30-day) remodeling behavior was used to divide patients into "poor remodelers" (<-5% lumen diameter change, n=6), "modest remodelers" (-5% to 25% change, n=29), and "robust remodelers" (>+25% change, n=30). Early remodeling category was significantly associated with primary patency rate at 2 years (log-rank, P=.02). A multivariable Cox proportional hazards model showed that modest remodelers (hazard ratio, 3.9; 95% confidence interval, 1.02-15; P=.04) and poor remodelers (hazard ratio, 13; 95% confidence interval; P=.008) had significantly higher hazard ratios for graft failure than robust early remodelers.

CONCLUSIONS

Early remodeling of the arterialized vein appears to predict midterm bypass graft patency. In addition to baseline diameter, race, inflammation, hsCRP, and statin use are associated with early adaptive remodeling, but the mechanisms for these observations are not understood.

Curved biodegradable microneedles for vascular drug delivery

Curved biodegradable microneedles for application to the outer surface of blood vessels are produced to enhance drug delivery to vascular tissues suffering from hyperplasia or atherosclerosis. Spatially discrete thermal drawing and post-annealing processes are employed to fabricate microneedles on a curved surface. Insertion of microneedles into arteries in vivo and ex vivo is demonstrated, and their mechanical properties and drug-delivery function are studied.

Challenges of distal bypass surgery in patients with diabetes: patient selection, techniques, and outcomes

Surgical revascularization of the lower extremity using bypass grafts to distal target arteries is an established, effective therapy for advanced ischemia. Recent multicenter data confirm the primacy of autogenous vein bypass grafting, yet there remains significant heterogeneity in the utilization, techniques, and outcomes associated with these procedures in current practice. Experienced clinical judgment, creativity, technical precision, and fastidious postoperative care are required to optimize long-term results. The diabetic patient with a critically ischemic limb offers some specific challenges; however, numerous studies demonstrate that the outcomes of vein bypass surgery in this population are excellent and define the standard of care. Technical factors, such as conduit and inflow/outflow artery selection, play a dominant role in determining clinical success. An adequate-caliber, good-quality great saphenous vein is the optimal graft for distal bypass in the leg. Alternative veins perform acceptably in the absence of the great saphenous vein, whereas prosthetic and other nonautogenous conduits have markedly inferior outcomes. Graft configuration (reversed, nonreversed, or in situ) seems to have little effect on outcome. Shorter grafts have improved patency. Inflow can be improved by surgical or endovascular means if necessary, and distal-origin grafts (eg, those arising from the superficial femoral or popliteal arteries) can perform as well as those originating from the common femoral artery. The selected outflow vessel should supply unimpeded runoff to the foot, conserve conduit length, and allow for adequate soft-tissue coverage of the graft and simplified surgical exposure. This review summarizes the available data linking patient selection and technical factors to outcomes and highlights the importance of surgical judgment and operative planning in the current practice of infrainguinal bypass surgery.

Risk factors for lower-extremity vein graft failure

Lower-extremity vein graft failure causes significant morbidity, increases health care costs, and negatively impacts patient quality of life. Identification of risk factors is essential for patient selection, risk factor modification, and identifying individuals who would benefit from more stringent surveillance protocols. Risk factors can be considered as either patient-related or technical. Here we discuss the patient-related risk factors for vein graft failure. Nontechnical factors related to the indication for operation include operation after a previously failed graft, or redo bypass, critical limb ischemia, and infection. Risk factors for vein graft failure are distinct from the risk factors for cardiovascular events. Young age and African American and Hispanic race are risk factors for lower-extremity vein graft failure. Hypercoaguable and inflammatory states also increase risk for vein graft failure. Therapy with statins is indicated in patients with peripheral atherosclerosis and may have beneficial effects on vein graft function, although further studies are needed in this area.

[S3 guidelines for diagnostics and treatment of peripheral arterial occlusive disease]

This report summarizes the most important aspects of the new German S3 guidelines for the diagnostics and treatment of peripheral arterial occlusive disease (PAOD) from March 2009. The guidelines include definitions and epidemiology of peripheral arterial occlusive disease, diagnostic methods including clinical and technical procedures as well as imaging methods, treatment by non-invasive, interventional and surgical methods and patient care during follow-up. In key messages recommendations are given which are graded corresponding to the scientific evidence concluded from the literature.

Are femorodistal bypass grafts for acute limb ischemia worthwhile?

Background: It has been shown that autogenous veins are associated with the best limb salvage rates for femorodistal bypass surgery. However, in emergency settings, when an autogenous vein is unavailable, use of synthetic graft material or amputation is a critical decision to make. Objective: To assess the appropriateness of femorodistal bypass grafts for acute limb ischemia in emergency settings. Methods: Patients who underwent emergent bypass and elective femorodistal bypass surgery between 1996 and 2006 were reviewed retrospectively in a single center. Results: There were 147 patients of which 84 had elective and 63 had emergent bypass. The graft patency rates for elective admissions were 44 and 25% vs. 25 and 23% for admissions for acute femorodistal graft surgery at 2 and 4 years, respectively (p < 0.004). Admissions for acute ischemia who were treated with prosthetic grafts had a primary patency of 24 vs. 27% for vein grafts at 2 years and 24 vs. 23% at 4 years (p = 0.33). In the acute femorodistal grafts group, primary patency at 2 years for vein and prosthetic grafts was 27 and 24% as compared to 42 and 32% for electives. These values for cumulative limb salvage rates for elective bypasses were 73 and 63% as compared to 52% at both time points in the acute femorodistal graft group (p < 0.004). In emergency settings, the limb salvage rate for acute femorodistal bypass with prosthetic grafts was 38%, and for vein grafts it was 62% at both time points (p = 0.08). Conclusion: The long term limb salvage rate of 38% suggests that emergent femorodistal revascularization is worthwhile.

Adaptive changes in autogenous vein grafts for arterial reconstruction: clinical implications

For patients with the most severe manifestations of lower extremity arterial occlusive disease, bypass surgery using autogenous vein has been the most durable reconstruction. However, the incidence of bypass graft stenosis and graft failure remains substantial and wholesale improvements in patency are lacking. One potential explanation is that stenosis arises not only from over exuberant intimal hyperplasia, but also due to insufficient adaptation or remodeling of the vein to the arterial environment. Although in vivo human studies are difficult to conduct, recent advances in imaging technology have made possible a more comprehensive structural examination of vein bypass maturation. This review summarizes recent translational efforts to understand the structural and functional properties of human vein grafts and places it within the context of the rich existing literature of vein graft failure.

Nonoperative active management of critical limb ischemia: initial experience using a sequential compression biomechanical device for limb salvage

Critical limb ischemia (CLI) patients are at high risk of primary amputation. Using a sequential compression biomechanical device (SCBD) represents a nonoperative option in threatened limbs. We aimed to determine the outcome of using SCBD in amputation-bound nonreconstructable CLI patients regarding limb salvage and 90-day mortality. Thirty-five patients with 39 critically ischemic limbs (rest pain = 12, tissue loss = 27) presented over 24 months. Thirty patients had nonreconstructable arterial outflow vessels, and five were inoperable owing to severe comorbidity scores. All were Rutherford classification 4 or 5 with multilevel disease. All underwent a 12-week treatment protocol and received the best medical treatment. The mean follow-up was 10 months (SD +/- 6 months). There were four amputations, with an 18-month cumulative limb salvage rate of 88% (standard error [SE] +/- 7.62%). Ninety-day mortality was zero. Mean toe pressures increased from 38.2 to 67 mm Hg (SD +/- 33.7, 95% confidence interval [CI] 55-79). Popliteal artery flow velocity increased from 45 to 47.9 cm/s (95% CI 35.9-59.7). Cumulative survival at 12 months was 81.2% (SE +/- 11.1) for SCBD, compared with 69.2% in the control group (SE +/- 12.8%) (p = .4, hazards ratio = 0.58, 95% CI 0.15-2.32). The mean total cost of primary amputation per patient is euro29,815 ($44,000) in comparison with euro13,900 ($20,515) for SCBD patients. SCBD enhances limb salvage and reduces length of hospital stay, nonoperatively, in patients with nonreconstructable vessels.

Is atherectomy the best first-line therapy for limb salvage in patients with critical limb ischemia?

OBJECTIVE

To determine the efficacy of atherectomy for limb salvage compared with open bypass in patients with critical limb ischemia.

METHODS

Ninety-nine consecutive bypass and atherectomy procedures performed for critical limb ischemia between January 2003 and October 2006 were reviewed.

RESULTS

A total of 99 cases involving TASC C (n = 43, 44%) and D (n = 56, 56%) lesions were treated with surgical bypass in 59 patients and atherectomy in 33 patients. Bypass and atherectomy achieved similar 1-year primary patency (64% vs 63%; P = .2). However, the 1-year limb salvage rate was greater in the bypass group (87% vs 69%; P = .004). In the tissue loss subgroup, there was a greater limb salvage rate for bypass patients versus atherectomy (79% vs 60%; P = .04).

CONCLUSIONS

Patients with critical limb ischemia may do better with open bypass compared with atherectomy as first-line therapy for limb salvage.

[Critical limb ischemia]

Critical limb ischemia can be divided into acute and chronic forms. All patients suspected of the acute form should be evaluated immediately, as urgent revascularization is usually necessary. Chronic critical limb ischemia is the most complicated type of peripheral artery disease (PAD). Typical for it are pain at rest and necrosis or gangrene. The most important known risk factors are nicotine, hypertension, diabetes, and hyperlipoproteinemia. Patients suffering from PAD run a significantly higher risk of cardiovascular or cerebrovascular events and therefore should be on permanent antithrombotic therapy as secondary prophylaxis. Besides clinical examination and determination of the ankle/brachial index, complementary imaging is mandatory. Here angiography is the gold standard. For therapy surgical and other interventional procedures are available. The decision on individual therapy follows an interdisciplinary approach based on an international consensus (TASC classification).

Lower extremity vein graft failure: a translational approach

Abstract

Patients with the most severe manifestations of lower extremity arterial occlusive disease often require peripheral bypass surgery for limb salvage and preservation of function. Although good quality saphenous vein offers the most durable conduit for reconstruction, 5-year failure rates are 30–50% and have remained largely unchanged for the past two decades. The majority of these failures occur within the first year of implantation, which is regarded as the most biologically active time during which the vein graft adapts to the arterial environment. Although intimal hyperplasia is generally regarded as the primary culprit of vein graft failure, geometric remodeling of the healing vein graft has recently emerged as a potentially significant contributing factor. While hemodynamic forces, including an increase in shear stress and wall tension, are undoubtedly central to the magnitude and direction of vein graft remodeling, we have determined that these forces alone cannot account for the extent of variability noted in early remodeling patterns. Therefore, we hypothesize that circulating factors, such as mediators of inflammation, may modulate the vein graft response to mechanical forces. This article reviews the definition and diagnosis of vein graft failure and summarizes our current efforts to understand the mechanisms of normal and abnormal vein graft adaptation to the arterial environment.