Management of Infrapopliteal Peripheral Arterial Occlusive Disease

The Curious Case of the Missing Limb on FDG PET Imaging

ABSTRACT

A 58-year-old woman with poorly controlled diabetes, peripheral vascular disease, and end-stage renal disease requiring hemodialysis was referred for 18 F-FDG PET/CT to evaluate for source of sepsis. She had history of prior left forefoot and right second toe amputation, as well as left lower-limb dry gangrene for which she declined surgical management. We present a case of a nonamputated lower limb demonstrating regions of absolute photopenia, consistent with dry gangrene.

Endovascular Interventions for Peripheral Artery Disease: A Contemporary Review

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS

The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Anterior, posterior, or all-vessel infrapopliteal revascularization in patients with moderate-severe claudication: Insights from the LIBERTY 360 study

BACKGROUND

Little data guides revascularization of infrapopliteal peripheral arterial disease (PAD) in patients with claudication. We assessed outcomes after infrapopliteal-only intervention for claudication in the LIBERTY 360 observational study.

METHODS

In this post hoc analysis, LIBERTY 360 patients (N = 128) with claudication and isolated infrapopliteal disease undergoing endovascular revascularization were divided by territory into anterior-vessel, posterior-vessel, or all-vessel groups. Patients were followed for periprocedural, in-hospital, and long-term outcomes. Logistic regression for odds ratios, Cox proportional hazard models, ANOVA, and Kaplan-Meier estimates were utilized to compare outcomes.

RESULTS

Patients underwent anterior (N = 37), posterior (N = 76), or all-vessel (N = 15) infrapopliteal revascularization. Initial procedural success was 86%, 86%, and 69% for anterior, posterior, and all-vessel groups, respectively. Each group had improvements in Rutherford classification (RC) from baseline to 2 years (mean RC change: -1.3, -1.5, and -1.5, respectively). Compared with all-vessel intervention, both anterior and posterior groups had lower rate of major adverse events (MAE) and target vessel revascularization (TVR) at 3 years (MAE: 12% and 15% in anterior and posterior groups, respectively compared with 51% in the all-vessel group; hazard ratios and 95% CIs 0.22 [0.06-0.74], p = .015; 0.24 [0.09-0.64], p = .004). Other outcomes were similar among the three groups. The anterior group showed more improvement in pain subdomain and total VascuQoL scores compared with posterior and all-vessel groups at 2 years (p = .016, p = .020 and p = .068, p = .009, respectively).

CONCLUSIONS

Both anterior or posterior revascularization have favorable outcomes and may be beneficial for improvement of symptoms in claudicants with isolated infrapopliteal PAD.

The use of drug-eluting stents in infrapopliteal arteries: an updated systematic review and meta-analysis of randomized trials

INTRODUCTION

Endovascular treatment below-the-knee is safe and effective but limited by poor patency. Coronary drug-eluting stents (DES) may play a role in providing mechanical scaffolding and deliver anti-proliferative drug to the site of vascular barotrauma to reduce the incidence of restenosis. Our aim was to evaluate and compare the use of contemporary DES with standard endovascular-therapies for atherosclerotic disease of infrapopliteal arteries.

EVIDENCE ACQUISITION

We performed a meta-analysis of randomized controlled trials comparing DES with conventional treatment for symptomatic peripheral artery disease (search date 30 August 2017). The primary endpoint was primary patency. Secondary endpoints were freedom from target lesion revascularization (TLR), major amputation, sustained Rutherford class improvement and mortality.

EVIDENCE SYNTHESIS

We identified 7 trials enrolling 801 randomly assigned patients (392 DES, 409 control). At the median follow-up of 12-months DES improved rates of primary patency (OR 3.49, 95%CI 2.38-5.12, I2=0%, P<0.00001), freedom from TLR (OR 2.19, 95%CI 1.30-3.69, I2=38%, P=0.003), major amputation (OR 0.56, 95%CI 0.31-0.99, I2=0%, P=0.049), and Rutherford class improvement (OR 1.62, 95%CI 1.01-2.59, I2=65%, P=0.046), but not mortality (OR 1.05, 95%CI 0.68-1.62; I2 =0%, P=0.91) compared to control. Subgroup analysis of primary patency favoured DES coated in sirolimus analogues compared to paclitaxel (Test for subgroup differences, Chi2=6.51, df=1, P=0.01, I2=84.6%).

CONCLUSIONS

At midterm follow-up DES significantly improved rates of primary patency, re-intervention, Rutherford class improvement and major amputation for the treatment of atherosclerotic disease of infrapopliteal arteries compared to control therapy, with no effect on patient survival. Stents coated in sirolimus analogues were more effective than paclitaxel.

AG490 suppresses EPO-mediated activation of JAK2-STAT but enhances blood flow recovery in rats with critical limb ischemia

Background

Erythropoietin (EPO) has been demonstrated to enhance recovery in ischemic organs through enhancing angiogenesis. In this study, we used an experimental critical limb ischemia (CLI) rat model to reveal the underlying mechanisms and directly examine the benefits of the anti-apoptotic capacity of EPO in the acute phase of limb ischemia and following blood flow recovery.

Methods

To determine the role of the JAK2/STAT pathway in EPO-enhanced recovery after CLI, male Sprague-Dawley rats (n = 8 for each group) were divided into group 1 (normal control), group 2 (CLI treated with normal saline), group 3 (CLI treated with EPO), group 4 (CLI treated with AG490, a JAK2 inhibitor), and group 5 (CLI treated with EPO and AG490). Animals were sacrificed either at day 1 or day 14 and biochemical and histopathological examination of ischemic quadriceps were conducted.

Results

At day 1, EPO administration reduced expression levels of apoptotic indices and activated the JAK2/STAT pathway; this activation was inhibited by additional AG490 treatment. Furthermore, the decrease in the size of the infarcted area, as well as activation of ERK1/2 and JNK showed similar regulatory trends with EPO or AG490 treatment. Of Interest, EPO and AG490 in combination showed a synergistic effect, increasing expression levels of antioxidants (GR, GPx, NQO-1) and decreasing transcriptional levels of pro-inflammatory factors (TNF-α, NF-kB). At day 14, laser Doppler analysis showed that the blood flow recovery was enhanced by EPO, AG490, or combined treatment.

Conclusion

Although inhibition of the JAK2/STAT pathways reduces the anti-apoptotic effects of EPO in the early phase of CLI, the benefits of AG490 in anti-inflammation and anti-oxidation still play a positive role in enhancing blood flow recovery after CLI.

Endovascular reconstruction of popliteal and infrapopliteal arteries for limb salvage and wound healing in patients with critical limb ischemia - A retrospective analysis

Background

Advancement in endovascular techniques has led to rapid growth in endovascular revascularization, and it has emerged as a treatment for critical limb ischemia (CLI). Clinical effectiveness of revascularization has been frequently judged by vessel patency and limb salvage, but there is paucity of reports on outcomes of the wound. We present a retrospective analysis of immediate angiographic and 3-month clinical outcome of patients who underwent endovascular reconstruction of popliteal and infrapopliteal arteries for CLI.

Methods

All patients who underwent endovascular reconstruction of popliteal and/or infrapopliteal arteries for CLI and >70% stenosis on digital subtraction angiography between March 2010 and November 2014 and had a clinical follow-up of at least 3 months were selected for analysis.

Results

34 patients underwent endovascular reconstruction. 9 patients (26%) underwent only POBA and remaining 25 (74%) underwent additional stenting. 13 patients (38%) had multiple segmental revascularization. 24 patients (71%) had successful vessel recanalization. Linear flow to foot in at least one artery could be achieved in 20 patients (59%) post revascularization. Successful wound healing occurred in 11 (35%) patients with an additional 7 (21%) patients showing clinical improvement in their wounds. Limb salvage was achieved in 33 patients (97%) at 3-month follow-up.

Conclusion

Endovascular revascularization of popliteal and infrapopliteal arteries is a feasible, safe, and effective procedure for the treatment of CLI. Normal inflow and outflow with at least one of the three infrapopliteal vessels being patent is essential for adequate healing of chronic ulcers and prevention of major amputation.

Amputation-Free Survival after Crural Percutaneous Transluminal Angioplasty for Critical Limb Ischemia

Background and Aim:

To evaluate the amputation-free survival after below the knee percutaneous transluminal angioplasty in a consecutive group of patients with critical ischemia of the lower extremity.

Materials and Methods:

A total of 70 consecutive patients with critical ischemia were treated with below the knee percutaneous transluminal angioplasty at the vascular center at Rigshospitalet with the purpose of limb salvage. All patients were deemed unfit for major surgery due to anatomical limitations or severe co-morbidity, and no prior attempts of revascularization were performed. Follow-up clinical examinations were performed within 6 weeks and after 1 year. All medical records were crosschecked with the national vascular registry ensuring a valid 1-year status in 97% of the patients.

Results:

A total of 15 major amputations were performed during follow-up, with 11 amputations performed within the first year. Complications after percutaneous transluminal angioplasty were rare. Cumulative mortality after 1 and 2 years was 22% and 34%, respectively. Amputation-free survival at 1 and 2 years of follow-up was 68% and 58%, respectively. There were no association between known risk factors such as diabetes, ischemic ulcers, cardiac disease, history of smoking, major amputation, or overall amputation.

Conclusion:

Below the knee percutaneous transluminal angioplasty in patients with end-stage peripheral arterial disease and critical limb ischemia is a safe procedure in relieving critical ischemia, reducing the short-term rate of a major amputation as opposed to best medical treatment alone.

Drug eluting devices for critically ill patients: can we apply lessons learned from the treatment of peripheral artery disease?

OBJECTIVE

To review the use of drug-eluting devices in peripheral arteries of critically ill patients

FINDINGS

Drug eluting stents and drug coated balloons are promising technologies and have become an important tool for the endovascular treatment of peripheral artery disease. The concept of local drug delivery to prevent restenosis due to intimal hyperplasia has been proven in several trials for different peripheral vascular beds. Especially for the treatment of patients with critical lower limb ischemia, improved patency could presumably improve wound healing, survival and limb salvage rates. However, until now, there is a paucity of evidence regarding these devices in critically ill patients and lessons learned must be extrapolated from non-critically ill patients at this time.

CONCLUSIONS

Restenosis rates can be reduced by drug eluting devices. Further study of the clinical impact of the use of drug eluting devices in the peripheral arteries will be required to determine if improved patency rates also can be translated into clinical benefit for critically ill patients.

Successful use of a gastrocnemius flap for an exposed PTFE femorodistal graft: a case report

Peripheral vascular disease (PVD) is a condition requiring aggressive management to minimise the associated increased morbidity and mortality. Femoro-distal bypass grafting is used in patients with extensive occlusion affecting the crural arteries and poor limb function, but is associated with infection, wound dehiscence and graft exposure. We report a case of a 73-year-old male with history of PVD and occluded ipsilateral femoro-distal bypass graft who underwent limb salvage surgery with a left 6 mm heparin-bonded polytetrafluoroethylene femoro-distal bypass graft in September 2011. He later presented with exposure of the graft over the lateral aspect of the knee following wound dehiscence. During surgery, the exposed portion of the graft was covered by a lateral gastrocnemius muscle flap with an overlying split thickness skin graft. Minor donor site healing problems were noted, but he otherwise made an excellent recovery. While gastrocnemius muscle flaps have been used to cover soft tissue tibial defects secondary to sarcoma and exposed knee joint prostheses, our case adds to the limited literature demonstrating successful salvage of an exposed synthetic graft as a viable alternative to amputation. We therefore recommend prompt referral to plastic services for the management of these complex wounds.

Retrograde pedal access for patients with critical limb ischemia

OBJECTIVE

Retrograde pedal access may allow the treatment of tibial occlusive lesions when standard endovascular techniques fail. We aimed to analyze the outcomes in patients with chronic limb ischemia (Rutherford class IV and V) who were not surgical candidates for a tibial bypass and had undergone an unsuccessful attempt at revascularization through an antegrade access.

METHODS

During a 3-year period, a retrograde pedal access was selectively chosen when a popliteal or tibial lesion could not be crossed through an antegrade approach. Retrograde pedal access was performed under ultrasound guidance using a 4F micropuncture coaxial sheath. All interventions were performed in a sheathless fashion using a 0.014- or 0.018-inch "bareback" wire as support for a 2- or 2.5-mm balloon angioplasty catheter to cross and treat tibial chronic total occlusions that could not be treated through an antegrade approach. Routine anticoagulation and dual-antiplatelet therapy were used periprocedurally. Antegrade access was used to treat any lesion that required a stent placement after the retrograde wire was snared and brought through the antegrade guidecatheter. Patient indications and comorbidities were recorded. Outcomes analyzed were limb salvage rate, periprocedural complications, and mortality. Mean and standard deviations were calculated. The Kaplan-Meier method was used to calculate limb salvage rates.

RESULTS

A review of the 681 lower extremity angiograms in which a patient had an intervention from July 2010 through December 2013 identified 13 patients (nine men) in whom a retrograde pedal access was performed (mean age, 71.4 ± 12.4 years). Among these, diabetes was present in 10 of 13 (77%) and chronic renal insufficiency (stages II-V) in nine (69%). Five (38%) had undergone contralateral amputation. Indications for a retrograde pedal revascularization were Rutherford chronic limb ischemia class IV in two (15%) and class V in 11 (85%). Technical success rate was 69% (nine of 13). A variety of popliteal (two of 13) and tibial (13 of 13) vessels were treated with angioplasty alone (10 of 13) or angioplasty/stent placement (three of 13) through a retrograde approach. The technical failures were due to inability to cross the occlusion(s). Periprocedurally, there was one myocardial infarction but no local complications, worsening renal insufficiency, or deaths. At a mean follow-up of 17.1 ± 10.3 months, the limb salvage rate was 77% (10 of 13). There was a high mortality rate of 23% (three of 13) on follow-up in this cohort, occurring at median 6 ± 4 months.

CONCLUSIONS

Retrograde pedal access for limb salvage in high-risk patients is feasible and safe, with acceptable limb salvage rates at intermediate follow-up. Appropriate candidates are those who have failed an antegrade intervention and are poor candidates for a tibial bypass. Future studies should test whether this mode of revascularization has favorable limb salvage rates in larger patient populations and seek to identify specific patient populations who will benefit from this technique.

Preoperative Statins and Limb Salvage After Lower Extremity Revascularization in the Medicare Population

Background—

Statins stabilize atherosclerotic plaque, decrease mortality after surgical procedures, and are linked to anti-inflammatory effects. The objective of this study was to evaluate preoperative administration of statins and longitudinal limb salvage after lower extremity endovascular revascularization and lower extremity open surgery.

Methods and Results—

Patients were selected from 2007 to 2008 Medicare claims using the International Classification of Diseases, Ninth Revision, Clinical Modification , diagnosis codes for claudication (N=8128), rest pain (N=3056), and ulceration/gangrene (N=11 770) and Current Procedural Terminology codes for endovascular revascularization (N=14 353) and open surgery (N=8601). Half (N=11 687) were identified as statin users before revascularization using Part D files. Amputations were identified using Current Procedural Terminology codes. Statin users compared with nonusers had lower amputation rates at 30 days (11.5% versus 14.4%; P <0.0001), 90 days (15.5% versus 19.3%; P <0.0001), and 1 year (20.9% versus 25.6%; P <0.0001). Survival analysis demonstrated improved limb salvage during 1 year for statin users compared with nonusers for the diagnosis of claudication ( P =0.003), a similar trend for rest pain ( P =0.061), and no improvement for ulceration/gangrene ( P =0.65).

Conclusions—

Preoperative statins were associated with improved 1-year limb salvage after lower extremity revascularization. The strongest association was found for patients with the diagnosis of claudication. Statins seem to be underused among Medicare patients with peripheral artery disease. Further evaluation of the use of preoperative statins and the potential benefits for peripheral vascular interventions is warranted.

A prospective randomized multicenter comparison of balloon angioplasty and infrapopliteal stenting with the sirolimus-eluting stent in patients with ischemic peripheral arterial disease: 1-year results from the ACHILLES trial

OBJECTIVES

The study investigated the efficacy and safety of a balloon expandable, sirolimus-eluting stent (SES) in patients with symptomatic infrapopliteal arterial disease.

BACKGROUND

Results of infrapopliteal interventions using balloon angioplasty and/or bare stents are limited by a relatively high restenosis rate, which could be potentially improved by stabilizing the lesion with a SES.

METHODS

Two hundred patients (total lesion length 27 ± 21 mm) were randomized to infrapopliteal SES stenting or percutaneous transluminal balloon angioplasty (PTA). The primary endpoint was 1-year in-segment binary restenosis by quantitative angiography.

RESULTS

Ninety-nine and 101 patients (mean age 73.4 years; 64% diabetics) were randomized to SES and PTA, respectively (8 crossover bailout cases to SES). At 1 year, there were lower angiographic restenosis rates (22.4% vs. 41.9%, p = 0.019), greater vessel patency (75.0% vs. 57.1%, p =0.025), and similar death, repeat revascularization, index-limb amputation rates, and proportions of patients with improved Rutherford class for SES versus PTA.

CONCLUSIONS

SES implantation may offer a promising therapeutic alternative to PTA for treatment of infrapopliteal peripheral arterial disease.