Below-the-ankle angioplasty and stenting for limb salvage: anatomical considerations and long-term outcomes

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Pedal medial arterial calcification influences the outcomes of isolated infra-malleolar interventions for chronic limb-threatening ischemia

OBJECTIVE

Inframalleolar disease is present in most diabetic patients presenting with tissue loss. Inframalleolar (pedal) artery disease and pedal medial arterial calcification (pMAC) are associated with major amputation in patients with chronic limb-threatening ischemia (CLTI). This study aimed to examine the impact of pMAC on the outcomes after isolated inframalleolar (pedal artery) interventions.

METHODS

A database of lower extremity endovascular intervention for patients with tissue loss between 2007 and 2022 was retrospectively queried. Patients with CLTI were selected, and those undergoing isolated inframalleolar intervention on the dorsalis pedis and medial and lateral tarsal arteries and who had foot x-rays were identified. X-rays were assessed blindly for pMAC and scored on a scale of 0 to 5. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention to treat analysis by the patient was performed. Amputation-free survival (survival without major amputation) was evaluated.

RESULTS

A total of 223 patients (51% female; 87% Hispanic; average age, 66 years; 323 vessels) underwent isolated infra-malleolar intervention for tissue loss. All patients had diabetes, 96% had hypertension, 79% had hyperlipidemia, and 63% had chronic renal insufficiency (55% of these were on hemodialysis). Most of the patients had Wound, Ischemia, and foot Infection (WIfI) stage 3 disease and had various stages of pMAC: severe (score = 5) in 48%, moderate (score = 2-4) in 31%, and mild (score = 0-1) in 21% of the patients. Technical success was 94%, with a median of one vessel treated per patient. All failures were in severe pMAC. Overall, major adverse cardiovascular events was 0.9% at 90 days after the procedure. Following the intervention, most patients underwent a planned forefoot amputation (single digit, multiple digits, ray amputation, or trans-metatarsal amputation). WIfI ischemic grade was improved by 51%. Wound healing at 3 months was 69%. Those not healing underwent below-knee amputations. The overall 5-year amputation-free survival rate was 35% ± 9%. The severity of pMAC was associated with decreased AFS.

CONCLUSIONS

Increasing severity of pMAC influences the technical and long-term outcomes of infra-malleolar intervention in diabetes. Severe pMAC is associated with amputation and should be considered as a variable in the shared decision-making of diabetic patients with CLTI.

Angiosome-Targeted Infrapopliteal Angioplasty: Impact on Clinical Outcomes-An Observational Study

Background: Revascularization based on the angiosome concept (AC) is a controversial subject because there is currently no clear evidence of its efficacy, due to the heterogeneity of patients (multiple and diverse risk factors and comorbidities, multiple variations in the affected angiosomes). Choke vessels change the paradigm of the AC, and the presence or absence of the plantar arch directly affects the course of targeted revascularization. The aim of this study was to evaluate the effect of revascularization based on the AC in diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: This retrospective analysis included 51 patients (40 men, 11 women), with a mean age of 69 years (66-72) and a total of 51 limbs, who presented with Rutherford 5-6 CLTI, before and after having undergone a drug-coated balloon angioplasty (8 patients) or plain balloon angioplasty (43). Between November 2018 and November 2019, all patients underwent below-the-knee balloon angioplasties and were followed up for an average of 12 months. The alteration of microcirculation was compared between directly and indirectly revascularized angiosomes. The study assessed clinical findings and patient outcomes, with follow-up investigations, comparing wound healing rates between the different revascularization methods. Patient records and periprocedural leg digital subtraction angiographies (DSA) were analyzed. Differences in outcomes after direct revascularization and indirect percutaneous transluminal angioplasty (PTa) were examined using Cox proportional hazards analysis, with the following endpoints: ulcer healing, limb salvage, and also amputation-free survival. Results: Direct blood flow to the angiosome supplying the ulcer area was achieved in 38 legs, in contrast to 13 legs with indirect revascularization. Among the cases, there were 39 lesions in the anterior tibial artery (ATA), 42 lesions in the posterior tibial artery (PTA), and 8 lesions in the peroneal artery (PA). According to a Cox proportional hazards analysis, having fewer than three (<3) affected angiosomes (HR 0.49, 95% CI 0.19-1.25, p = 0.136) was associated with improved wound healing. Conversely, wound healing outcomes were least favorable after indirect angioplasty (p = 0.206). When adjusting the Cox proportional hazard analysis for the number of affected angiosomes, it was found that direct drug-coated angioplasty resulted in the most favorable wound healing (p = 0.091). At the 1-year follow-up, the major amputation rate was 17.7%, and, according to a Cox proportional hazards analysis, atrial fibrillation (HR 0.85, 95% CI 0.42-1.69, p = 0.637), hemodialysis (HR 1.26, 95% CI 0.39-4.04, p = 0.699), and number of affected angiosomes > 3 (HR 0.94, 95% CI 0.63-1.39, p = 0.748) were significantly associated with poor leg salvage. Additionally, direct endovascular revascularization was associated with a lower rate of major amputation compared to indirect angioplasty (HR 1.09, 95% CI 0.34-3.50, p = 0.884). Conclusions: Observing the angiosomes concept in decision-making appears to result in improved rates of arterial ulcer healing and leg salvage, particularly in targeted drug-coated balloon angioplasty for diabetic critical limb ischemia, where multiple angiosomes are typically affected.

How to Approach Below-the-Ankle Arterial Interventions

Critical limb ischemia, also referred to as chronic limb-threatening ischemia, is a major medical problem leading to limb amputations if not managed properly with a multispecialty team. Establishment of sufficient arterial flow to the foot is an integral part of this care. During the past two to three decades, arterial revascularization has become primarily endovascular with open surgical approaches significantly diminished in comparison. As techniques, tools, and experiences of the interventionalist have improved, the ability to recanalize more complex lesions has become more commonplace. We are at an age that even the arteries below the ankle can be accessed for complex interventions and even be recanalized if necessary. This article will discuss common arterial interventions performed below the ankle.

Severe inframalleolar disease is an independent predictor of adverse limb outcomes after endovascular revascularization in chronic limb-threatening ischemia

OBJECTIVE

In the present study, we evaluated the effects of inframalleolar (IM) disease on the occurrence of major adverse limb events (MALE) in patients undergoing endovascular revascularization for chronic limb-threatening ischemia (CLTI).

METHODS

Patients who had undergone endovascular revascularization for CLTI between January 2015 and December 2019 at two university-affiliated hospitals were reviewed retrospectively. Patients with severe IM disease (pedal score of 2) were compared with those with mild to moderate IM disease (score of 0 or 1) using the Global Vascular Guidelines. The primary outcome was MALE (open revascularization, acute leg ischemia, major amputation). The secondary outcomes were mortality, reintervention, major adverse cardiac events, and perioperative complications ≤30 days after endovascular revascularization, primary limb-based patency, and the occurrence of any limb event (defined as any amputation, acute leg ischemia, or open revascularization). Kaplan-Meier estimates were used to compare the primary outcome, and the Cox proportion hazard model was used to assess the effects of IM disease.

RESULTS

The study included 167 limbs in 149 patients (36% female; mean age, 74 ± 12 years). Severe IM disease was identified in 71 limbs (43%). No differences were found in the baseline characteristics, except for a higher prevalence of dyslipidemia in the patients with severe IM disease (66% vs 43%; P = .003). Most patients in both groups had had a WIfI (Wound, Ischemia, foot Infection) score of 4 (severe IM disease, 64%; vs mild to moderate IM disease, 57%; P = .462) and GLASS (global limb anatomic severity scale) III anatomy (severe IM disease, 54%; vs mild to moderate IM disease, 48%; P = .752). The Kaplan-Meier estimates showed that severe IM disease was associated with lower freedom from MALE (69% vs 82%; P = .026). The Cox proportion hazard regression model showed that severe IM disease was an independent predictor of increased MALE and amputation risk (hazard ratio, 1.715; 95% confidence interval, 1.015-2.896; P = .044) after adjusting for covariates. During follow-up, patients with severe IM disease had had mortality (27% vs 31%; P = .567) and reintervention (42% vs 38%; P = .608) similar to those for patients with mild to moderate IM disease. Primary limb-based patency was also similar (79% vs 84%; P = .593) at a mean follow-up of 3.8 ± 0.8 years.

CONCLUSIONS

Severe IM disease was prevalent in 43% of limbs that had undergone endovascular revascularization for CLTI and was associated with lower freedom from MALE. Severe IM disease also independently increased the hazard of adverse limb outcomes and amputations in patients with CLTI by >70%, highlighting its importance as a measure of foot perfusion.

Twenty-Four Month Results of Tack-Optimized Balloon Angioplasty Using the Tack Endovascular System in Below-the-Knee Arteries

PURPOSE

To report 24 month safety and efficacy of the Tack Endovascular System for treatment of post-percutaneous transluminal angioplasty (PTA) infrapopliteal dissections in patients with critical limb-threatening ischemia (CLTI).

MATERIALS AND METHODS

The Tack-Optimized Balloon Angioplasty (TOBA) II below-the-knee (BTK) study was a prospective, multicenter, single-arm evaluation of the Tack Endovascular system for post-PTA infrapopliteal dissection repair. Patients with Rutherford Clinical Category (RC) 3 to 5 and a post-PTA dissection(s) of the BTK arteries were enrolled. The 30 day primary safety endpoint was a composite of major adverse limb events (MALE) and all-cause perioperative death (POD). The primary effectiveness endpoint was a composite of MALE at 6 months and 30 day POD. Outcomes were assessed as observational endpoints at 24 months.

RESULTS

Tack-Optimized Balloon Angioplasty II BTK enrolled 233 patients; all patients had a post-PTA dissection(s) and received ≥1 Tack implant (range, 1-16). Mean age was 74.4±10.0 years and 67.4% were men. Most patients had CLTI (RC 3: 16.3%; RC 4/5: 83.7%). Mean target lesion length was 80±49 mm. Moderate to severe calcium was present in 89 (35.8%) lesions and total occlusions were present in 118 (47.6%) lesions. Kaplan-Meier freedom from MALE at 24 months + POD at 30 days was 92.2% and 24 month freedom from clinically-driven target lesions revascularization was 73.6%. Kaplan-Meier target limb salvage was 95.7% and amputation-free survival was 75.4%. Improvements in functional status and quality of life were observed through 24 months.

CONCLUSION

The TOBA II BTK study demonstrated sustained safety and efficacy through 24 months in patients treated for post-PTA dissection(s) of BTK lesions.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02942966.

Foot Revascularization Avoids Major Amputation in Persons with Diabetes and Ischaemic Foot Ulcers

The study aims to evaluate the effectiveness of foot revascularization in persons with diabetic foot ulcers (DFUs) and below-the-ankle (BTA) arterial disease. Consecutive patients referred for a new active ischaemic DFU requiring lower limb revascularization were considered. Among those, only patients with a BTA arterial disease were included. Revascularization procedures were retrospectively analysed: in the case of successful foot revascularization (recanalization of pedal artery, or plantar arteries or both) or not, patients were respectively divided in two groups, successful foot perfusion (SFP) and failed foot perfusion (FFP). Healing, minor and major amputation at 12 months of follow-up were evaluated and compared. Eighty patients (80) were included. The mean age was 70.5 ± 10.9 years, 55 (68.7%) were male, 72 (90%) were affected by type 2 diabetes with a mean duration of 22.7 ± 11.3 years. Overall 45 (56.2%) patients healed, 47 (58.7%) had minor amputation and 13 (16.2%) major amputation. Outcomes for SFP and FFP were respectively: healing (89.3 vs. 9.1%, p < 0.0001), minor amputation (44.7 vs. 78.8%, p = 0.0001), major amputation (2.1 vs. 36.3%, p < 0.0001). Failed foot revascularization resulted an independent predictor of non-healing, minor amputation, and major amputation. Foot revascularization is mandatory to achieve healing and avoid major amputation in persons with ischaemic DFU and BTA arterial disease.

Systematic review of inframalleolar endovascular interventions and rates of limb salvage, wound healing, restenosis, rest pain, reintervention and complications

Objectives

Peripheral artery disease is estimated to affect 237 million individuals worldwide. Critical limb ischaemia, also known as chronic limb threatening ischaemia is a consequence of the progression of peripheral artery disease which occurs in ∼21% of patients over a five-year period. The aim of this systematic review is to assess the use of additional below-the-ankle angioplasty in comparison to the use of above-the-ankle angioplasty alone, and the subsequent rates of amputation, wound healing, restenosis, rest pain, reintervention and complications.

Methods

This systematic review was undertaken in accordance with PRISMA guidelines following a registered protocol (CRD42019154893). Online databases were searched using a search strategy of 20 keywords. Included articles reported the outcome for inframalleolar (pedal artery, pedal arch, plantar arteries) angioplasty with additional proximal angioplasty in comparison to proximal angioplasty alone. GRADE assessment was applied to assess the quality of the evidence.

Results

After screening 1089 articles, 10 articles met the inclusion criteria. Comparative performance assessment of below-the-ankle with above-the-ankle versus above-the-ankle angioplasty alone was undertaken in 3 articles, with the remaining 7 articles reporting outcomes of below-the-ankle with above-the-ankle angioplasty with no distinct comparator group. Significant decrease in major lower limb amputation at the last follow-up in the below-the-ankle group when compared with the above-the-ankle angioplasty alone group was observed in a single study (3.45% vs. 14.9%, p < 0.05). Improved wound healing rate at follow-up in the below-the-ankle group versus above-the-ankle angioplasty alone group was also reported in a single study (59.3% vs. 38.1%, p < 0.05). Subsequent rate of amputation after below-the-ankle angioplasty has been estimated as 23.5%.

Conclusion

To date, there is a lack of studies assessing inframalleolar interventions and their use in improving limb salvage, wound healing and symptomatology. Prospective RCTs should be undertaken with adequate participant numbers to be sufficiently powered and report clinically important end-points.

Six-month pivotal results of tack optimized balloon angioplasty using the Tack Endovascular System in below-the-knee arteries

OBJECTIVE

No vascular implant is commercially available in the United States to treat post-angioplasty dissections in below-the-knee (BTK) arteries. The Tack Endovascular System (Intact Vascular, Wayne, Pa) is purpose-built to repair postpercutaneous transluminal angioplasty (PTA) BTK dissections. A trial was conducted to investigate the safety and efficacy of the first-of-a-kind implantable BTK device to treat post-PTA dissections in the setting of critical limb ischemia.

METHODS

The present prospective, single-arm, multicenter study evaluated the Tack Endovascular System for treating post-PTA dissections in the mid/distal popliteal, tibial, and peroneal arteries. The primary safety endpoint was major adverse limb events (MALE) plus perioperative death (POD), assessed at 30 days after the index procedure. The primary efficacy endpoint was a composite of MALE at 6 months and POD. The unpowered secondary endpoint was primary patency at 6 months. With no available on-label comparator, the primary endpoints of the present trial were determined using objective performance goals from a systematic literature search. The secondary endpoints included Tacked segment patency and target limb salvage at 6 months. The 6-month results are reported.

RESULTS

Of the 233 patients enrolled, 117 (50.2%) had Rutherford class 5 and 78 (33.5%) had Rutherford class 4. A total of 341 post-PTA dissections were treated. Each patient received at least one Tack implant, and 100% of the dissections resolved according to the angiographic core laboratory findings. The primary safety and efficacy endpoints were both met. The rate of MALE plus POD at 30 days was 1.3% (3 of 228) and freedom from MALE at 6 months plus POD at 30 days was 95.6% (196 of 205). The 6-month Tacked segment patency was 82.1% (247 of 301) and target limb salvage was 98.5% (202 of 205). The Kaplan-Meier freedom from clinically driven target lesion revascularization and amputation-free survival at 6 months was 92.0% and 95.7%, respectively. Rutherford improvement was reported in 79.4% (158 of 199). Most (90 of 122; 73.8%) preexisting wounds had healed or were improving.

CONCLUSIONS

The Tack Endovascular System is safe and effective for treating post-PTA BTK dissections through 6 months, with favorable rates of MALE plus POD, patency, clinically driven target lesion revascularization, limb salvage, and wound healing.

Limb Salvage in Diabetic Patients With Ischemic Heel Ulcers

The purpose of this study is to investigate the outcomes of diabetic individuals with ischemic heel ulcers. The study group was composed of a consecutive sample of persons with diabetic ischemic foot ulcers managed by a preset multidisciplinary limb salvage protocol, including revascularization through endovascular technique. The outcome measures were healing, major amputation (above the ankle), and death at 1-year of follow-up. The outcomes between patients with heel ulcers (HUs) and without (NHUs) were compared. A total of 254 patients were recruited. There were 50/254 (19.7%) HUs and 204/254 (79.3%) NHUs. Overall, 190/254 (74.8%) patients healed. The rate of healing for HUs and NHUs was 30/50 (60%) and 160/204 (78.4%); P = .03, respectively. Major amputation occurred in 24/254 (9.4%) patients. The rates of major amputation for HUs and NHUs were 10/50 (20%) and 14/204 (6.9%; P = .002), respectively; 40/254 (15.7%) patients died, unhealed. The rates of mortality for HUs and NHUs were 10/50 (20%) and 30/204 (14.7%; P = .07), respectively. In HUs patients, absence of infection [95% CI = 3.1 (1.6-5.5); P = .002] and superficial ulcers [95% CI = 4.4 (2.2-9.3); P = .0001] were independent predictors of healing, whereas revascularization failure [95% CI = 8.1 (1.5.0-19.4); P = .0001], involvement of the plantar arch [95% CI = 6.3 (2.0-15.4); P = .0001], and dialysis [95% CI = 2.2 (1.3-4.5); P = .006] were independent predictors of major amputation. A multidisciplinary approach achieves good rate of limb salvage in people with diabetic ischemic heel ulcers.

Below-the-ankle arterial disease severely impairs the outcomes of diabetic patients with ischemic foot ulcers

AIM

To evaluate the impact of below-the-ankle (BTA) arterial disease in people with ischemic diabetic foot ulcers (DFUs).

METHODS

Patients with ischemic DFUs treated by a pre-set limb salvage protocol including peripheral revascularization were included. They were divided in two groups according to the involvement of BTA arteries (BTA+) or not (BTA-). Not healing, minor amputation, major amputation and mortality have been evaluated as primary outcome. Revascularization failure has been evaluated as secondary outcome.

RESULTS

The study group was composed of 272 patients, 120 (44.1%) belonging to BTA+ group and 152 (55.9%) to BTA-. After 1 year of follow-up the outcomes for BTA+ and BTA- were respectively: not healing (40.8 vs 17.8%, p < 0.0001), minor amputation (80.8 vs 20.4%, p < 0.0001), major amputation (18.3 vs 6.6%, p = 0.002), mortality (16.7% vs 10.5%, p = 0.001). The rate of revascularization failure was respectively 38.3 vs 11.2%, p < 0.0001. At the multivariate analysis BTA arterial disease resulted an independent predictor of not healing [OR 3.5 (CI 95% 2.3-6.1) p = 0.0001], minor amputation [OR 3.1 (1.5-5.9) p < 0.0001] and revascularization failure [OR 3.5 (1.9-6.3) p = 0.0001]. BTA+ patients with successful BTA revascularization showed lower rate of not healing (37.8 vs 89.1%) p < 0.0001, minor amputation (74.3 vs 91.3%) p = 0.002 and major amputation (8.1 vs 34.8%) p = 0.0003 in comparison to patients with unsuccessful BTA revascularization.

CONCLUSION

BTA arterial disease severely impairs the outcomes of diabetics with ischemic foot ulcers. BTA revascularization reduces the rate of not healing, minor and major amputation.

Advances in the Management of Peripheral Artery Disease

PURPOSE OF REVIEW

This paper provides a concise update on the management of peripheral artery disease (PAD).

RECENT FINDINGS

PAD continues to denote a population at high risk for mortality but represents a threat for limb loss only when associated with foot ulcers, gangrene, or infections. Performing either angiogram or non-invasive testing for all patients with foot ulcers, gangrene, or foot infections will help increase the detection of PAD, and refined revascularization strategies may help optimize wound healing in this patient group. Structured exercise programs are becoming available to more patients with claudication as methods to improve adherence to community-based exercise programs will improve. Finally, ensuring more patients with PAD receive aspirin therapy and statins may improve long-term survival, while further research will help determine if adding newer antiplatelet or anticoagulant medications may reduce leg amputations in selected patients. Clinicians should have a low threshold to obtain an angiogram and to pursue revascularization in patients with foot ulcers, gangrene, or foot infections. In patients with claudication, clinicians should maximize the benefits derived from exercise therapy and medical management before offering percutaneous or surgical revascularization.

Below-the-ankle Angioplasty: Current Evidence and Future Perspectives

Over 20 million adults in Europe suffer from peripheral arterial disease (PAD). The annual incidence of PAD is approximately 2.4%, while the annual incidence of critical limb ischaemia (CLI), the last and most severe stage of PAD, has been reported to be 0.4%. Endovascular angioplasty and/or stenting of infrapopliteal disease is, today, an established treatment for critical limb ischaemia. The main technical advantages of endovascular treatment over open bypass surgery include the possibility to revascularise more than one infrapopliteal vessels and, most importantly, to treat outflow pedal vessel disease or even reconstitute the pedal arch. Data of below-the-ankle angioplasty are beginning to sum up and the contribution of pedal arch angioplasty in limb salvage and wound healing are currently under investigation. In this review, currently available data and the future perspectives on below-the-ankle and pedal arch endovascular treatment will be presented.

Functional prognosis of critical limb ischemia and efficacy of restoration of direct flow below the ankle

Objective

Patients with critical limb ischemia have serious systemic comorbidities and are at high risk of impairment of limb function. In this study, we assessed the prognostic factors of limbs after revascularization.

Methods

In this retrospective single-center cohort study, from April 2008 to December 2012, we treated 154 limbs of 121 patients with critical limb ischemia by the endovascular therapy-first approach based on the patients’ characteristics. The primary end point was amputation-free survival. Secondary end points were patency of a revascularized artery, major adverse limb events, or death. Furthermore, we investigated the ambulatory status one year after revascularization as prognosis of limb function.

Results

Endovascular therapy was performed in 85 limbs in 65 patients as the initial therapy (endovascular therapy group) and surgical reconstructive procedures (bypass group) were performed in 69 limbs in 56 patients. Early mortality within 30 days was not observed in either group. The primary patency rate was significantly better in the bypass group than in the endovascular therapy group ( p < 0.0001). Furthermore, the secondary patency rate was similar between the two groups ( p = 0.0096). There were no significant differences in amputation-free survival and major adverse limb event between the two groups. Univariate analysis showed that ulcer healing ( p < 0.0001), no hypoalbuminemia ( p = 0.0019), restoration of direct flow below the ankle ( p = 0.0219), no previous cerebrovascular disease ( p = 0.0389), and Rutherford 4 ( p = 0.0469) were predictive factors for preservation of ambulatory status one year after revascularization. In multivariate analysis, ulcer healing ( p < 0.0001) and restoration of direct flow below the ankle ( p = 0.0060) were significant predictors.

Conclusions

Ulcer healing and restoration of direct flow below the ankle are independently associated with prognosis of limb functions in patients who undergo infrainguinal arterial reconstruction.

BAD transmission and SAD distribution: a new scenario for critical limb ischemia

BACKGROUND

Most of the studies on peripheral artery disease (PAD) focused on above-the-ankle artery disease, while less is known about foot artery disease. We hypothesize a scenario were two different diseases can be present in PAD patients, big artery disease (BAD) and small artery disease (SAD), overlapping at the foot level; the aim of this study is to evaluate their prevalence and their correlation with risk factors and critical limb ischemia (CLI) in a large cohort of patients with symptomatic PAD.

METHODS

We retrospectively reviewed 1915 limbs of 1613 patients (502 females, mean age 72.4±10.8 years) who underwent angiography between September 2009 and November 2013. Age, sex, diabetes, smoke history, high blood pressure, dialysis and BMI were considered as risk factors. Logistic regression was performed to test the association of arterial lesions patterns and CLI, and to evaluate the association between risk factors and lesion localization.

RESULTS

SAD was present in 414 patients (25.2%). Patients with disease of any of plantar, dorsalis pedis arteries and SAD faced higher risk of CLI (OR=13.25, 95% CI: 1.69-104.16). SAD was associated with diabetes and dialysis (both: OR=4.85; dialysis only: OR=3.60; diabetes only: OR=1.70; none: reference OR; P<0.01), weight (underweight: OR=1.10; normal: reference OR; overweight: OR=0.81; obese: OR=0.60; P=0.03), while women and tobacco smokers were less likely to have SAD (women: OR=0.68; P<0.01; tobacco use: OR=0.54; P<0.01).

CONCLUSIONS

SAD was strongly and independently associated with CLI, diabetes and dialysis. Thus, SAD should be regarded as a leading actor in CLI.

Inframalleolar Intervention for Limb Preservation

Critical limb ischemia (CLI) is a relatively prevalent and highly morbid condition. Patients with CLI have a poor prognosis, especially in the setting of incomplete revascularization. Traditionally, achieving optimal revascularization has been limited by the high prevalence of small-vessel disease in this population. More recently, advanced endovascular techniques, increased operator experience, and new technologies have enabled complete revascularization of inframalleolar disease with encouraging clinical results. In this article, we present an approach to endovascular therapy for inframalleolar revascularization of patients with CLI.

A New Hemodynamic Ex Vivo Model for Medical Devices Assessment

BACKGROUND

In-stent restenosis (ISR) remains a major public health concern associated with an increased morbidity, mortality, and health-related costs. Drug-eluting stents (DES) have reduced ISR, but generate healing-related issues or hypersensitivity reactions, leading to an increased risk of late acute stent thrombosis. Assessments of new DES are based on animal models or in vitro release systems, which have several limitations. The role of flow and shear stress on endothelial cell and ISR has also been emphasized. The aim of this work was to design and first evaluate an original bioreactor, replicating ex vivo hemodynamic and biological conditions similar to human conditions, to further evaluate new DES.

METHODS

This bioreactor was designed to study up to 6 stented arteries connected in bypass, immersed in a culture box, in which circulated a physiological systolo-diastolic resistive flow. Two centrifugal pumps drove the flow. The main pump generated pulsating flows by modulation of rotation velocity, and the second pump worked at constant rotation velocity, ensuring the counter pressure levels and backflows. The flow rate, the velocity profile, the arterial pressure, and the resistance of the flow were adjustable. The bioreactor was placed in an incubator to reproduce a biological environment.

RESULTS

A first feasibility experience was performed over a 24-day period. Three rat aortic thoracic arteries were placed into the bioreactor, immersed in cell culture medium changed every 3 days, and with a circulating systolic and diastolic flux during the entire experimentation. There was no infection and no leak. At the end of the experimentation, a morphometric analysis was performed confirming the viability of the arteries.

CONCLUSIONS

We designed and patented an original hemodynamic ex vivo model to further study new DES, as well as a wide range of vascular diseases and medical devices. This bioreactor will allow characterization of the velocity field and drug transfers within a stented artery with new functionalized DES, with experimental means not available in vivo. Another major benefit will be the reduction of animal experimentation and the opportunity to test new DES or other vascular therapeutics in human tissues (human infrapopliteal or coronary arteries collected during human donation).

Treating calf and pedal vessel disease: the extremes of intervention

Recent developments in catheter, balloon, and guidewire technology have increased the scope for endovascular treatments in the management of complex and challenging disease in the calf and foot. The antegrade femoral approach remains the starting point for most interventions, but there is a growing role for procedures performed from unconventional access such as the pedal arteries. This article reviews the indications for intervention, atypical access, and the choice of equipment for these extreme interventions.