High lipoprotein(a) is associated with major adverse limb events after femoral artery endarterectomy

BACKGROUNDS AND AIMS

Elevated lipoprotein(a) (Lp[a]) has been identified as a causal risk factor for cardiovascular disease including peripheral arterial disease (PAD). Although Lp(a) is associated with the diagnosis of PAD, it remains elusive whether there is an association of Lp(a) with cardiovascular and limb events in patients with severe PAD.

METHODS

Preoperative plasma Lp(a) levels were measured in 384 consecutive patients that underwent iliofemoral endarterectomy and were included in the Athero-Express biobank. Our primary objective was to assess the association of Lp(a) levels with Major Adverse Limb Events (MALE). Our secondary objective was to relate Lp(a) levels to Major Adverse Cardiovascular Events (MACE) and femoral plaque composition that was acquired from baseline surgery.

RESULTS

During a median follow-up time of 5.6 years, a total of 225 MALE were recorded in 132 patients. Multivariable analysis, including history of peripheral intervention, age, diabetes mellitus, end stage renal disease and PAD disease stages, showed that Lp(a) was independently associated with first (HR of 1.36 (95% CI 1.02-1.82) p = .036) and recurrent MALE (HR 1.36 (95% CI 1.10-1.67) p = .004). A total of 99 MACE were recorded but Lp(a) levels were not associated with MACE.sLp(a) levels were significantly associated with a higher presence of smooth muscle cells in the femoral plaque, although this was not associated with MALE or MACE.

CONCLUSIONS

Plasma Lp(a) is independently associated with first and consecutive MALE after iliofemoral endarterectomy. Hence, in patients who undergo iliofemoral endarterectomy, Lp(a) could be considered as a biomarker to enhance risk stratification for future MALE.

Results of a prospective observational study of autologous peripheral blood mononuclear cell therapy for no-option critical limb-threatening ischemia and severe diabetic foot ulcers

Background

Cell therapy with autologous peripheral blood mononuclear cells (PB-MNCs) may help restore limb perfusion in patients with diabetes mellitus and critical limb-threatening ischemia (CLTI) deemed not eligible for revascularization procedures and consequently at risk for major amputation (no-option). Fundamental is to establish its clinical value and to identify candidates with a greater benefit over time. Assessing the frequency of PB circulating angiogenic cells and extracellular vesicles (EVs) may help in guiding candidate selection.

Methods

We conducted a prospective, non-controlled, observational study on no-option CLTI diabetic patients that underwent intramuscular PB-MNCs therapy, which consisted of more cell treatments repeated a maximum of three times. The primary endpoint was amputation rate at 1 year following the first treatment with PB-MNCs. We evaluated ulcer healing, walking capability, and mortality during the follow-up period. We assessed angiogenic cells and EVs at baseline and after each cell treatment, according to primary outcome and tissue perfusion at the last treatment [measured as transcutaneous oxygen pressure (TcPO₂)].

Results

50 patients were consecutively enrolled and the primary endpoint was 16%. TcPO₂ increased after PB-MNCs therapy (17.2 ± 11.6 vs 39.1 ± 21.8 mmHg, p < .0001), and ulcers healed with back-to-walk were observed in 60% of the study population (88% of survivors) during follow-up (median 1.5 years). Patients with a high level of TcPO₂ (≥ 40 mmHg) after the last treatment showed a high frequency of small EVs at enrollment.

Conclusions

In no-option CLTI diabetic patients, PB-MNCs therapy led to an improvement in tissue perfusion, a high rate of healing, and back-to-walk. Coupling circulating cellular markers of angiogenesis could help in the identification of patients with a better clinical benefit over time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01629-y.

Diagnosis of silent coronary ischemia with selective coronary revascularization might improve 2-year survival of patients with critical limb-threatening ischemia

BACKGROUND

Patients with critical limb-threatening ischemia (CLTI) have had poor long-term survival after lower extremity revascularization owing to coexistent coronary artery disease. A new cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFR_CT), can identify patients with ischemia-producing coronary stenosis who might benefit from coronary revascularization. We sought to determine whether the diagnosis of silent coronary ischemia before limb salvage surgery with selective postoperative coronary revascularization can reduce the incidence of adverse cardiac events and improve the survival of patients with CLTI compared with standard care.

METHODS

Patients with CLTI and no cardiac history or symptoms who had undergone preoperative testing to detect silent coronary ischemia with selective postoperative coronary revascularization (group I) were compared with patients with standard preoperative cardiac clearance and no elective postoperative coronary revascularization (group II). Both groups received guideline-directed medical care. Lesion-specific coronary ischemia in group I was defined as FFR_CT of ≤0.80 distal to a stenosis, with severe ischemia defined as FFR_CT of ≤0.75. The endpoints included all-cause death, cardiovascular (CV) death, myocardial infarction (MI), major adverse CV events (i.MACE; CV death, MI, unplanned coronary revascularization, stroke) through 2 years of follow-up.

RESULTS

Groups I (n = 111) and II (n = 120) were similar in age (66 ± 9 vs 66 ± 7 years), gender (78% vs 83% men), comorbidities, and surgery performed. In group I, unsuspected, silent coronary ischemia was found in 71 of 103 patients (69%), with severe ischemia in 58% and left main coronary ischemia in 8%. Elective postoperative coronary revascularization was performed in 47 of 71 patients with silent ischemia (66%). In group II, the status of silent coronary ischemia was unknown. The median follow-up was >2 years for both groups. The 2-year outcomes for groups I and II were as follows: all-cause death, 8.1% and 20.0% (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.18-0.84; P = .016); CV death, 4.5% and 13.3% (HR, 0.32; 95% CI, 0.11-0.88; P = .028); MI, 6.3% and 17.5% (HR, 0.33; 95% CI, 0.14-0.79; P = .012); and major adverse CV events, 10.8% and 23.3% (HR, 0.44; 95% CI, 0.22-0.88; P = .021), respectively.

CONCLUSIONS

The preoperative evaluation of patients with CLTI and no known coronary artery disease using coronary FFR_CT revealed silent coronary ischemia in two of every three patients. Selective coronary revascularization of patients with silent coronary ischemia after recovery from limb salvage surgery resulted in fewer CV deaths and MIs and improved 2-year survival compared with patients with CLTI who had received standard cardiac evaluation and care. Prospective controlled studies are required to further define the role of FFR_CT in the evaluation and treatment of patients with CLTI.

Prospective study on clinical characteristics of Japanese diabetic patients with chronic limb-threatening ischemia presenting Fontaine stage IV

The aim of this prospective cross-sectional study was to reveal clinical characteristics of Japanese diabetic patients with chronic limb-threatening ischemia (CLTI) presenting ischemic unhealed ulcer/gangrene (Fontaine stage IV) in the real-world settings. The present study included 132 Japanese diabetic patients who underwent endovascular therapy for CLTI presenting Fontaine stage IV. The prevalence of diabetes-related complications, as well as prior history of ankle-brachial index (ABI) measurement before CLTI onset, was evaluated adopting multiple imputation (50 times). Duration of diabetes was referred to as time from diagnosis. The patients were aged 70 ± 10 years, with duration of diabetes 23 ± 12 years. The diabetes-related complications were so common that only 17% (95% confidence interval: 11-24%) and 25% (17-33%) of the population were free from advanced micro- and macroangiopathies, respectively. The clustering of advanced macroangiopathies was not significantly associated with duration of diabetes (P = 0.62). On the other hand, that of advanced microangiopathies was significantly positively associated with duration of diabetes (P = 0.004). However, even in patients with duration of diabetes < 10 years, as many as 63% (38-87%) of patients had at least one advanced microangiopathy. Only 31% (22-39%) of the patients had prior history of ABI measurement before CLTI onset. The history was inversely associated with age (P = 0.005). In conclusion, the advanced diabetes-related complications were highly prevalent, even in those whose diabetes was diagnosed less than a decade before. In addition, only a few patients had ever undergone ABI measurement before CLTI onset.

Validation of randomized controlled trial-derived models for the prediction of postintervention outcomes in chronic limb-threatening ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) represents the most severe form of peripheral artery disease and has a large impact on quality of life, morbidity, and mortality. Interventions are aimed at improving tissue perfusion and averting amputation and secondary cardiovascular complications with an optimal risk-benefit ratio. Several prediction models regarding postprocedural outcomes in CLTI patients have been developed on the basis of randomized controlled trials to improve clinical decision-making. We aimed to determine model performance in predicting clinical outcomes in selected CLTI cohorts.

METHODS

This study validated the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL), Finland National Vascular registry (FINNVASC), and Prevention of Infrainguinal Vein Graft Failure (PREVENT III) models in data sets from a peripheral artery disease registry study (Athero-Express) and two randomized controlled trials of CLTI in The Netherlands, Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) and Percutaneous Transluminal Angioplasty and Drug-eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia (PADI). Receiver operating characteristic (ROC) curve analysis was used to calculate their predictive capacity. The primary outcome was amputation-free survival (AFS); secondary outcomes were all-cause mortality and amputation at 12 months after intervention.

RESULTS

The BASIL and PREVENT III models showed predictive values regarding postintervention mortality in the JUVENTAS cohort with an area under the ROC curve (AUC) of 81% and 70%, respectively. Prediction of AFS was poor to fair (AUC, 0.60-0.71) for all models in each population, with the highest predictive value of 71% for the BASIL model in the JUVENTAS population. The FINNVASC model showed the highest predictive value regarding amputation risk in the PADI population with AUC of 78% at 12 months.

CONCLUSIONS

In general, all models performed poor to fair in predicting mortality and amputation. Because the BASIL model performed best in predicting AFS, we propose use of the BASIL model to aid in the clinical decision-making process in CLTI. However, improvements in performance have to be made for any of these models to be of real additional value in clinical practice.

Risk factors for reamputations in patients amputated after revascularization for critical limb-threatening ischemia

OBJECTIVE

Despite vascular intervention, patients with critical limb-threatening ischemia (CLTI) have a high risk of amputation. Furthermore, this group has a high risk for stump complications and reamputation. The primary aim of this study was to identify risk factors predicting reamputation after a major lower limb amputation in patients revascularized because of CLTI. The secondary aim was to investigate mortality after major lower limb amputation.

METHODS

There were 288 patients who underwent a major ipsilateral amputation after revascularization because of CLTI in Stockholm, Sweden, during 2007 to 2013. The main outcome was ipsilateral reamputation.

RESULTS

Of 288 patients, 50 patients had a reamputation and 222 died during the 11-year follow-up. Patients with ischemic pain as an indication for primary amputation had nearly four times higher risk for a reamputation compared with those with a nonhealing ulcer (subdistribution hazard ratio, 3.55; confidence interval, 1.55-8.17). Higher age was associated with an increased risk for death in the multivariable analysis (hazard ratio, 1.03; confidence interval, 1.02-1.04).

CONCLUSIONS

Patients with ischemic pain as an indication for amputation have an elevated risk of reamputation. Ischemic pain may be indicative of a more extensive and proximal ischemia compared with patients with foot tissue loss. An extended evaluation of the preoperative circulation before amputation may facilitate the choice of amputation level and could lead to a reduction of reamputations.

Effects of dialysis on peripheral arterial disease

End-stage renal disease is an independent risk factor for the development of peripheral arterial disease, with considerably worse outcomes in patients with concomitant diseases. It is important to realize the widespread, yet frequently asymptomatic, nature of peripheral arterial disease in patients with end-stage renal disease due to the presence of other comorbidities that decrease activity levels and sensation to allow for early recognition and timely medical management to try and mitigate otherwise poor outcomes. Despite their high risk, properly selected patients derive benefit from revascularization; both open and endovascular approaches provide similar outcomes in terms of overall survival, amputation-free survival, and limb salvage, with perhaps a slight preference toward open repair. This narrative review of the literature evaluates the epidemiology, pathophysiology, outcomes, and management strategies that provide the best possible outcomes for patients with peripheral arterial disease and end-stage renal disease.

Influence of time interval between endovascular intervention and free flap transfer on flap outcomes in critical limb-threatening ischemia: A retrospective analysis of 64 consecutive cases

BACKGROUND

Arterial revascularization and free flap reconstruction is safe and effective for limb salvage in patients with critical limb-threatening ischemia (CLTI). This study aimed to determine whether reconstruction outcomes were affected by the time interval between endovascular treatment and free flap transfer in lower extremity reconstruction for critical limb ischemia.

METHODS

Patients who underwent endovascular intervention and subsequent free flap reconstruction with >6 months of follow-up were reviewed. Those with wounds with oncological and traumatic etiologies were excluded. Patients' demographics, risk factors, details of microsurgical procedures, details of endovascular intervention, and flap outcomes were collected.

RESULTS

Overall, 64 consecutive patients (M:F = 50:14 and mean age, 57.3 [range, 29-82] years) were evaluated between November 2011 and October 2019. Angioplasty failed in three patients. For soft-tissue reconstruction, anterolateral free flaps were used most frequently (n = 54 and 84.4%). Flap-related complications developed in 12 cases, of which five cases included total flap necrosis. The interval between endovascular intervention and free flap transfer was not associated with flap loss in multivariate regression analysis. Patients with kidney transplants and higher serum creatinine were associated with total flap necrosis. Advanced age, failed angioplasty, and perfusion status of the pedal arch were associated with major flap complications.

CONCLUSION

The time interval between endovascular treatment and free flap reconstruction was not associated with flap complications. Free flap reconstruction of chronic wounds caused by CLTI can be safely planned regardless of the time duration from preoperative angioplasty.

Inframalleolar thrice distal puncture in a single endovascular treatment session for successful revascularization

BACKGROUND

Most patients with chronic limb-threatening ischemia (CLTI) have infrapopliteal arterial disease, which are often challenging to treat. In endovascular treatment (EVT) for these complex lesions, establishing retrograde access is an essential option not only for guidewire crossing but also for device delivery. However, no EVT case has yet been reported requiring inframalleolar thrice distal puncture in a single EVT session so far.

CASE PRESENTATION

A 60-year-old CLTI patient with grade 3 Wound, Ischemia and foot Infection (WIfI) classification underwent EVT for occluded dorsal artery and posterior tibial artery. First, we conducted successful balloon angioplasty of the posterior tibial artery by establishing a retrograde approach via the lateral plantar artery. To treat the occlusion of the dorsal artery, we punctured the first dorsal metatarsal artery, and retrogradely advanced a guidewire to the dorsal artery occlusion; however, the microcatheter could not follow the guidewire. Therefore, we punctured the occluded distal anterior tibial artery and introduced the retrograde guidewire into the puncture needle. After guidewire externalization, we pulled up the retrograde microcatheter into the occlusion of dorsal artery using the "balloon deployment using forcible manner" technique. Thereafter, we were able to advance the antegrade guidewire into the retrograde microcatheter. After guidewire externalization, an antegrade balloon catheter was delivered and inflated for the purpose of dorsal artery dilation and hemostasis at the "needle rendezvous" point. Consecutively, balloon dilation was performed for puncture site hemostasis of the first dorsal metatarsal artery and complete hemostasis was achieved. Finally, we confirmed good vascular patency and favorable blood flow. After revascularization, transmetatarsal amputation was performed and the wound healed favorably.

CONCLUSIONS

We can markedly increase the success rate of revascularization by effectively utilizing the retrograde approach in EVT for complex chronic total occlusions in infrapopliteal arterial diseases.

Differences in major limb outcomes by indication for lower extremity endovascular revascularization in patients receiving hemodialysis

The incidence of lower extremity artery disease (LEAD) in patient receiving hemodialysis is remarkably higher than the general population. The treatment strategy and prognosis for LEAD patients differs depending on whether a patient has intermittent claudication (IC) or critical limb-threatening ischemia (CLTI). However, the distinction between the prognosis in HD-dependent patients with IC and CLTI has not been fully elucidated. This study is to determine whether indication of PAD has a distinct impact on major adverse cardiovascular and cerebrovascular events (MACCE) and limb events in patients receiving hemodialysis. The current study included 2321 prospectively enrolled patients from the Tokyo taMA peripheral vascular intervention research ComraDE registry (UMIN-CTR no. UMIN000015100) between September 2014 and December 2016. Out of the enrolled patients, 1644 were not receiving hemodialysis (non-HD patients) and 603 were receiving hemodialysis (HD patients). A composite of all-cause death, myocardial infarction, and stroke events defined as MACCE; while limb events were defined as a composite of unscheduled major amputation, unscheduled major lower limb surgery, acute limb ischemia, unscheduled endovascular treatment, and target lesion revascularization. Propensity score matching was applied among the non-HD and HD patients, in whole group, IC subgroup, and CLTI subgroup. Kaplan-Meier analysis was used for the analysis of outcomes for the whole group, IC subgroup, and the CLTI subgroup. CLTI accounted for 75.5% of the HD patients, whereas IC was 63.4% in the non-HD patients. The HD patients exhibited more frequent below-the-knee lesions than those in the non-HD patients in both IC (p = 0.01) and CLTI (p < 0.001) subgroups. Overall, HD patients exhibited a significantly higher rate of MACCE at 24 months. This trend was similar for limb events in whole group and CLTI subgroup. In contrast, no significant differences in outcomes for limb events were found in IC subgroup. Although, prognosis after EVT in HD patients were significantly worse than non-HD patients, comparable outcome with non-HD patients was observed in the patients treated for IC. Clinical trial registration: This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR No. UMIN000015100).

Prognostic impact of atrial fibrillation on the outcomes of peripheral artery disease according to preoperative symptoms for endovascular revascularization

Peripheral artery disease (PAD) and atrial fibrillation (AF) are associated with major cardiovascular and cerebrovascular events (MACCE). However, outcomes stratified according to the preoperative symptoms of PAD in patients with AF have not been sufficiently investigated. This was a retrospective study of prospectively collected data pertaining to 2237 patients (1179 patients with intermittent claudication [IC] and 1058 patients with critical limb-threatening ischemia [CLTI]) who underwent endovascular therapy at 34 hospitals between August 2014 and August 2016. AF was present in 91 (7.7%) patients with IC and 150 (14.2%) patients with CLTI. In the CLTI group, patients with AF had a higher event rate of MACCE and all-cause death than those without AF (1-year rates of freedom from MACCE: 0.66 and 0.81 in patients with and without AF, respectively, p < 0.001). In contrast, in the IC group, there was no statistically significant difference in the rates of MACCE between patients with and without AF. In the Cox multivariate analysis, AF was a significant predictor of MACCE in patients with CLTI but not in patients with IC, even after adjusting for covariates. The impact of AF on the outcome of patients with PAD was greater in those with CLTI. Further studies are needed to clarify the possible mechanisms underlying these differences.

A Multicenter Prospective Interventional Trial of Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans

BACKGROUND

Thromboangiitis obliterans (TAO) can lead to the development of critical limb-threatening ischemia (CLTI). Despite conventional treatments, such as smoking cessation or revascularization, young patients (<50 years) still require limb amputation. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation has been tested and shown to have reasonable efficacy in CLTI. In this multicenter prospective clinical trial, we evaluated the safety and efficacy of BM-MNC implantation in CLTI patients with TAO.

METHODS AND RESULTS

We enrolled 22 CLTI patients with skin perfusion pressure (SPP) <30 mmHg. The primary endpoint of this trial is the recovery of SPP in the treated limb after a 180-day follow-up period. Secondary endpoints include the pain scale score and transcutaneous oxygen pressure (TcPO2). One patient dropped out during follow-up, leaving 21 patients (mean age 48 years, 90.5% male, Fontaine Class IV) for analysis. BM-MNC implantation caused no serious adverse events and increased SPP by 1.5-fold compared with baseline. Surprisingly, this effect was sustained over the longer term at 180 days. Secondary endpoints also supported the efficacy of this novel therapy in relieving pain and increasing TcPO2. Major amputation-free and overall survival probabilities at 3 years among all enrolled patients were high (95.5% and 89.5%, respectively).

CONCLUSIONS

BM-MNC implantation showed safety and significant efficacy in CLTI patients with TAO.

Spinal Neuromodulation for Peripheral Arterial Disease of Lower Extremities: A Ten-Year Retrospective Analysis

OBJECTIVE

This long-term retrospective study evaluated the survival and amputation outcome of subjects who received neuromodulation therapy for the management of peripheral arterial disease (PAD).

MATERIALS AND METHODS

The study reviews the health data of a single cohort of 51 patients who received spinal neuromodulation (spinal cord stimulation [SCS] or dorsal root ganglion stimulation [DRG-S]) for PAD from 2007 to 2022 in a single German center. Survival rate and major amputation rate were determined. Pain, quality of life, walking distance, and opioid usage were assessed before implantation (baseline), one, six, and 12 months (M) after implantation, and then annually (during a follow-up visit). Implant-related complications also were documented.

RESULTS

In total, 51 patients (37 men [mean age 68.9 ± 10.2 years], 14 women [mean age (68.7 ± 14.6 years]) underwent SCS (n = 49) or DRG-S (n = 2) implantation owing to persistent ischemic pain. The follow-up mean years ± SD is 4.04 ± 2.73. At baseline, patients were classified as Rutherford's category 3 (n = 23), category 4 (n = 15) or category 5 (n = 9). At 24 M, 42 of 47 patients did not require a major amputation after the implant. All the patients reported nearly complete pain relief from pain at rest. A total of 75% of patients were able to walk >200 m, and 87% of patients who used opioids at baseline were off this medication at 24 M. Overall, 93% of patients reported an improvement in their overall health assessment. These improved outcomes were sustained through years three to 10 for patients who have reported outcomes.

CONCLUSIONS

Our single-center data support the efficacy of spinal neuromodulation for improvements in limb salvage, pain relief, mobility, and quality of life. The data also show that neuromodulative therapy has a long-term therapeutic effect in patients with chronic limb pain with Rutherford category 3, 4, and 5 PAD.

The direct extravascular calcium interruption arterial procedure technique for heavily calcified vessels

Severely calcified lesions continue to plague endovascular interventions by negatively affecting the acute and long-term results. A new technique was developed to allow balloon crossing or to treat persistent recoil. In the direct extravascular calcium interruption arterial procedure technique, an artery forceps is percutaneously introduced to modify the plaque after conventional techniques have failed. In this initial experience, the direct extravascular calcium interruption arterial procedure technique was successful as a bailout option in patients in whom balloon crossing was impossible or recoil was untreatable even with high-pressure balloons.

Unraveling the differential mechanisms of revascularization promoted by MSCs & ECFCs from adipose tissue or umbilical cord in a murine model of critical limb-threatening ischemia

BACKGROUND

Critical limb-threatening ischemia (CLTI) constitutes the most severe manifestation of peripheral artery disease, usually induced by atherosclerosis. CLTI patients suffer from high risk of amputation of the lower extremities and elevated mortality rates, while they have low options for surgical revascularization due to associated comorbidities. Alternatively, cell-based therapeutic strategies represent an effective and safe approach to promote revascularization. However, the variability seen in several factors such as cell combinations or doses applied, have limited their success in clinical trials, being necessary to reach a consensus regarding the optimal "cellular-cocktail" prior further application into the clinic. To achieve so, it is essential to understand the mechanisms by which these cells exert their regenerative properties. Herein, we have evaluated, for the first time, the regenerative and vasculogenic potential of a combination of endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs) isolated from adipose-tissue (AT), compared with ECFCs from umbilical cord blood (CB-ECFCs) and AT-MSCs, in a murine model of CLTI.

METHODS

Balb-c nude mice (n:32) were distributed in four different groups (n:8/group): control shams, and ischemic mice (after femoral ligation) that received 50 µl of physiological serum alone or a cellular combination of AT-MSCs with either CB-ECFCs or AT-ECFCs. Follow-up of blood flow reperfusion and ischemic symptoms was carried out for 21 days, when mice were sacrificed to evaluate vascular density formation. Moreover, the long-term molecular changes in response to CLTI and both cell combinations were analyzed in a proteomic quantitative approach.

RESULTS

AT-MSCs with either AT- or CB-ECFCs, promoted a significant recovery of blood flow in CLTI mice 21 days post-ischemia. Besides, they modulated the inflammatory and necrotic related processes, although the CB group presented the slowest ischemic progression along the assay. Moreover, many proteins involved in the repairing mechanisms promoted by cell treatments were identified.

CONCLUSIONS

The combination of AT-MSCs with AT-ECFCs or with CB-ECFCs promoted similar revascularization in CLTI mice, by restoring blood flow levels, together with the modulation of the inflammatory and necrotic processes, and reduction of muscle damage. The protein changes identified are representative of the molecular mechanisms involved in ECFCs and MSCs-induced revascularization (immune response, vascular repair, muscle regeneration, etc.).

Fundamentals of wound care for amputation prevention

The initial skin breakdown and subsequent healing processes are complex and influenced by various parameters, including systemic factors, infectious bioburden, and perfusion. Vascular wounds comprise inadequate inflow (due to peripheral artery disease), microvascular damage (result of diabetes mellitus), or vasoconstriction. Normal healing of acute wounds occurs in a sequence of defined stages; however, if a dysregulated inflammatory state ensues, it is classified as chronic. Both chronic and vascular wounds carry an increased risk of amputation. Therefore, holistic wound care is crucial in preventing limb loss. This review outlines a systematic approach to wound assessment and examines the latest recommendations for managing vascular wounds, focusing on strategies for preventing amputations.

Utilization of coronary computed tomography angiography and computed tomography-derived fractional flow reserve in a critical limb-threatening ischemia cohort

Objective

Patients with peripheral arterial disease (PAD) have a significant risk of myocardial infarction and death secondary to concomitant coronary artery disease (CAD). This is particularly true in patients with critical limb-threatening ischemia (CLTI) who exceed a 20% mortality rate at 6 months despite standard treatment with risk factor modification. Although systematic preoperative coronary testing is not recommended for patients with PAD without cardiac symptoms, the clinical manifestations of CAD are often muted in patients with CLTI due to poor mobility and activity intolerance. Thus, the true incidence and impact of "silent" CAD in a CLTI cohort is unknown. This study aims to determine the prevalence of ischemia-producing coronary artery stenosis in a CLTI cohort using coronary computed tomography angiography (cCTA) and computed tomography (CT)-derived fractional flow reserve (FFRCT), a noninvasive imaging modality that has shown significant correlation to cardiac catheterization in the detection of clinically relevant coronary ischemia.

Methods

Patients presenting with newly diagnosed CLTI at our institution from May 2020 to April 2021 were screened for underlying CAD. Included subjects had no known history of CAD, no cardiac symptoms, and no anginal equivalent complaints at presentation. Patients underwent cCTA and FFRCT evaluation and were classified by the anatomic location and severity of CAD. Significant coronary ischemia was defined as FFRCT ≤0.80 distal to a >30% coronary stenosis, and severe coronary ischemia was documented at FFRCT ≤0.75, consistent with established guidelines.

Results

A total of 170 patients with CLTI were screened; 65 patients (38.2%) had no coronary symptoms and met all inclusion/exclusion criteria. Twenty-four patients (31.2%) completed cCTA and FFRCT evaluation. Forty-one patients have yet to complete testing secondary to socioeconomic factors (insurance denial, transportation inaccessibility, testing availability, etc). The mean age of included subjects was 65.4 ± 7.0 years, and 15 (62.5%) were male. Patients presented with ischemic rest pain (n = 7; 29.1%), minor tissue loss (n = 14; 58.3%) or major tissue loss (n = 3; 12.5%). Significant (≥50%) coronary artery stenosis was noted on cCTA in 19 of 24 patients (79%). Significant left main coronary artery stenosis was identified in two patients (10%). When analyzed with FFRCT, 17 patients (71%) had hemodynamically significant coronary ischemia (FFRCT ≤0.8), and 54% (n = 13) had lesion-specific severe coronary ischemia (FFRCT ≤0.75). The mean FFRCT in patients with coronary ischemia was 0.70 ± 0.07. Multi-vessel disease pattern was present in 53% (n = 9) of patients with significant coronary stenosis.

Conclusions

The use of cCTA-derived fractional flow reserve demonstrates a significant percentage of patients with CLTI have silent (asymptomatic) coronary ischemia. More than one-half of these patients have lesion-specific severe ischemia, which may be associated with increased mortality when treated solely with risk factor modification. cCTA and FFRCT diagnosis of significant coronary ischemia has the potential to improve cardiac care, perioperative morbidity, and long-term survival curves of patients with CLTI. Systemic improvements in access to care will be needed to allow for broad application of these imaging assessments should they prove universally valuable. Additional study is required to determine the benefit of selective coronary revascularization in patients with CLTI.

Cost-utility analysis of early versus delayed endovascular intervention in critical limb-threatening ischemia patients with rest pain

OBJECTIVE

The prevalence of chronic limb-threatening ischemia (CLTI) and poor health outcomes are high in Germany. Serious consequences of CLTI such as amputation and mortality can be effectively prevented by the early use of evidence-based therapeutic measures such as endovascular intervention. We have developed a cost-utility analysis to compare endovascular intervention with bare metal stents (BMSs) and endovascular intervention after conservative treatment from the German payer perspective.

METHODS

A Markov model, with a 5-year time horizon and seven states, was developed: (1) intervention, (2) stable 1, (3) major amputation, (4) reintervention, (5) stable 2, (6) care, and (7) all-cause death. Transition probabilities were obtained by pooling the outcomes from multiple clinical studies. The costs were estimated using data from the German diagnosis-related group system, the German rehabilitation fund, and related literature. Health-state utilities were obtained from the reported data. The primary outcomes were the quality-adjusted life-years (QALYs) and costs.

RESULTS

Early BMS intervention after 5 years resulted in a cost of €23,913 and an increase of 2.5 QALYs per patient, and endovascular intervention with BMS after conservative treatment after 5 years resulted in a cost of €18,323 and an increase of 2 QALYs per patient. The incremental cost-effectiveness ratio was €12,438. The number of major amputations was reduced by 6%. The results of the structural, deterministic, and probabilistic sensitivity analyses were robust.

CONCLUSIONS

Early endovascular intervention with BMS resulted in more QALYs and a reduced risk of major amputation for early-stage CLTI patients. Our results showed that early endovascular intervention is very cost-effective according to World Health Organization recommended cost-effectiveness thresholds. However, the clinical decision regarding the use of early endovascular intervention should be determined by individual patient-level eligibility and the physician's judgment.

Sciatic nerve atrophy as a risk factor for impaired wound healing in patients with chronic limb-threatening ischemia

OBJECTIVE

Patients with chronic limb-threatening ischemia (CLTI) typically undergo revascularization as the standard treatment. However, some still require major amputations post-revascularization. Because revascularization is invasive and costly, avoiding it may benefit patients with low likelihoods of wound healing. The Global Vascular Guidelines suggest primary amputation for patients unsuited to revascularization. Although previous research has linked frailty to limb prognosis, skeletal and bone frailties impact survival rather than limb outcomes. This study examines the association between sciatic nerve atrophy and limb prognosis in patients with CLTI.

METHODS

This single-center, retrospective study included patients with tissue loss CLTI who underwent successful revascularizations at Kyushu Medical Center (2015-2020). Sciatic nerve cross-sectional areas (CSAs) were measured using computed tomography scans above the bifurcation of the tibial and peroneal nerves. The CSA cutoff value for predicting wound healing was established using receiver operating characteristic analysis. Patients were grouped based on whether their CSA was larger (normal) or smaller (atrophy) than CSA cutoff value. Outcomes assessed included wound healing rates, amputation-free survival (AFS), and overall survival (OS).

RESULTS

Among 188 patients (226 limbs), the mean sciatic nerve CSA was 27.5 ± 0.7 mm2. A CSA cutoff of 23.6 mm2 (area under the curve = 0.81; sensitivity = 0.85; specificity = 0.71) was identified. Patients were categorized into normal (n = 147) and atrophy (n = 79) groups. The atrophy group had higher rates of nonambulatory status (38% vs 23%; P = .029), ischemic heart disease (47% vs 28%; P = .008), cerebrovascular disease (50% vs 35%; P = .045), end-stage renal disease (55% vs 37%; P = .024), and lower serum albumin (3.3 ± 0.06 vs 3.6 ± 0.05; P = .001). Six-month wound healing rates were 87.3% in the normal group vs 27.3% in the atrophy group (P < .001). Three-year AFS was 59.3% in the normal group vs 20.0% in the atrophy group (P < .001), and 3-year OS was 71.3% vs 57.8% (P = .022). Factors associated with impaired wound healing included age (hazard ratio [HR], 1.01; P = .045), low serum albumin (HR, 1.80; P = .001), ischemic heart disease (HR, 1.75; P = .002), end-stage renal disease (HR, 1.71; P = .002), and sciatic nerve atrophy (HR, 5.21; P < .001). Multivariate analysis identified age (HR, 1.02; P = .012) and sciatic nerve atrophy (HR, 5.08; P < .001) as independent risk factors for impaired wound healing after revascularizations.

CONCLUSIONS

Sciatic nerve atrophy correlates with poorer wound healing, AFS, and OS in patients with CLTI. Sciatic nerve assessment may guide decisions regarding limb salvage eligibility.

Antithrombotic therapy following lower extremity endovascular revascularization: The results of a survey of vascular specialists

Objective

Antithrombotic therapy improves endovascular intervention outcomes for peripheral artery disease. However, there are limited data guiding the choice and duration of these adjuvant therapies. Thus, we explored current antithrombotic prescribing preferences among vascular interventionalists, hypothesizing that there are varied and inconsistent treatment practices among providers.

Methods

We developed and distributed a de-identified RedCap survey via Twitter and email to Vascular Quality Initiative members (February 2023). Multiple-choice questions queried antithrombotic agents and treatment durations for a clinical vignette (a claudicant on 81 mg aspirin and statin) with different arterial disease locations (iliac, femoropopliteal, or tibial vessels) and different revascularization strategies (angioplasty or stenting, with and without drug-coating). Antithrombotic options included monotherapies with antiplatelet agents or low-dose rivaroxaban; dual therapies with aspirin combined with a P2Y12 inhibitor (dual antiplatelet therapy, DAPT) or low-dose rivaroxaban (dual pathway inhibition or DPI); or triple therapy with aspirin, a P2Y12 inhibitor, and low-dose rivaroxaban. Options for therapy duration included 30, 90, 180, and 365 days, or indefinitely.

Results

There were 199 respondents (17% female, 68% White race, 63% academic, 88% vascular surgery). Across all treatment scenarios, respondents selected DAPT (n = 171/199; 86%) in at least one revascularization scenario, followed by aspirin monotherapy (n = 83/199; 42%) and DPI (n = 49/199; 25%). Therapy choice did differ by both anatomic location and revascularization strategy (P < .05). DAPT was most selected following femoropopliteal revascularization (n = 165/199, 83%) and bare metal stenting (n = 162/198, 82%). However, aspirin monotherapy was most selected following iliac level revascularization (n = 52/197; 26%) and following percutaneous transluminal angioplasty at any level (n = 51/182; 28%). DPI was most selected following tibial revascularization (n = 39/184; 21%) and following percutaneous transluminal angioplasty (n = 38/182; 21%). Among those who selected DAPT, the 90-day (n = 99/171; 58%) duration was preferred. Those who selected DPI favored indefinite treatment durations (n = 34/49; 69%). Indefinite DAPT and DPI therapy were more commonly selected for distal level revascularization (P < .05). Rivaroxaban utilization was limited secondary to cost (n = 108/178; 61%), lack of demonstrated effectiveness (n = 75/178; 42%), and concern for safety and bleeding (n = 27/178; 15%).

Conclusions

Following lower extremity endovascular treatment of peripheral artery disease, a 90-day duration of DAPT remains the most commonly selected antithrombotic regimen despite the emergence of DPI as an evidence-based antithrombotic therapy. The variability in provider preferred antithrombotic agent and treatment duration emphasizes the need for high-quality evidence for the medical optimization of revascularization outcomes.

The impact of revascularization strategy on clinical failure, hemodynamic failure, and chronic limb-threatening ischemia symptoms in the BEST-CLI Trial

OBJECTIVE

Sustained clinical and hemodynamic benefit after revascularization for chronic limb-threatening ischemia (CLTI) is needed to resolve symptoms and prevent limb loss. We sought to compare rates of clinical and hemodynamic failure as well as resolution of initial and prevention of recurrent CLTI after endovascular (ENDO) vs bypass (OPEN) revascularization in the Best-Endovascular-versus-best-Surgical-Therapy-in-patients-with-CLTI (BEST-CLI) trial.

METHODS

As planned secondary analyses of the BEST-CLI trial, we examined the rates of (1) clinical failure (a composite of all-cause death, above-ankle amputation, major reintervention, and degradation of WIfI stage); (2) hemodynamic failure (a composite of above-ankle amputation, major and minor reintervention to maintain index limb patency, failure to an initial increase or a subsequent decrease in ankle brachial index of 0.15 or toe brachial index of 0.10, and radiographic evidence of treatment stenosis or occlusion); (3) time to resolution of presenting CLTI symptoms; and (4) incidence of recurrent CLTI. Time-to-event analyses were performed by intention-to-treat assignment in both trial cohorts (cohort 1: suitable single segment great saphenous vein [SSGSV], N = 1434; cohort 2: lacking suitable SSGSV, N = 396), and multivariate stratified Cox regression models were created.

RESULTS

In cohort 1, there was a significant difference in time to clinical failure (log-rank P < .001), hemodynamic failure (log-rank P < .001), and resolution of presenting symptoms (log-rank P = .009) in favor of OPEN. In cohort 2, there was a significantly lower rate of hemodynamic failure (log-rank P = .006) favoring OPEN, and no significant difference in time to clinical failure or resolution of presenting symptoms. Multivariate analysis revealed that assignment to OPEN was associated with a significantly lower risk of clinical and hemodynamic failure in both cohorts and a significantly higher likelihood of resolving initial and preventing recurrent CLTI symptoms in cohort 1, including after adjustment for key baseline patient covariates (end-stage renal disease [ESRD], prior revascularization, smoking, diabetes, age >80 years, WIfI stage, tissue loss, and infrapopliteal disease). Factors independently associated with clinical failure included age >80 years in cohort 1 and ESRD across both cohorts. ESRD was associated with hemodynamic failure in cohort 1. Factors associated with slower resolution of presenting symptoms included diabetes in cohort 1 and WIfI stage in cohort 2.

CONCLUSIONS

Durable clinical and hemodynamic benefit after revascularization for CLTI is important to avoid persistent and recurrent CLTI, reinterventions, and limb loss. When compared with ENDO, initial treatment with OPEN surgical bypass, particularly with available saphenous vein, is associated with improved clinical and hemodynamic outcomes and enhanced resolution of CLTI symptoms.

The Human Acellular Vessel (HAV) as a vascular conduit for infrainguinal arterial bypass

Autologous vein is the optimal conduit for peripheral arterial bypass surgery, a standard recently highlighted by findings from the BEST-CLI trial. The Human Acellular Vessel is a novel biologic conduit produced using regenerative medicine technologies with structural and mechanical properties like a human blood vessel. Not yet approved by the United States Food and Drug Administration, the Human Acellular Vessel is being studied as an alternative bypass conduit in patients with peripheral arterial disease, vascular injury, and those in need of arteriovenous access for hemodialysis. This report describes and illustrates the technical aspects of intraoperative handling specific to the use of this new and innovative technology.

Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans - Study Protocol for a Multicenter Prospective Interventional Trial

Background: Patients with thromboangiitis obliterans (TAO) can develop critical limb-threatening ischemia (CLTI) and require limb amputation. Smoking cessation and exercise therapy are recommended as standard treatments, and revascularization by bypass surgery or endovascular therapy (EVT) is required for patients with CLTI. However, there are many cases in which revascularization is difficult because of vascular characteristics, and the patency rate after revascularization remains unsatisfactory. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation is used clinically, with many trials demonstrating long-term efficacy and safety of the technique in patients with CLTI, especially that caused by TAO. To expand the use of BM-MNCs implantation in clinical practice, further evidence is required in patients with CLTI caused by TAO.

Methods and Results: This trial is a multicenter, prospective, non-randomized interventional trial of an Advanced Medicine B treatment approach. We aim to enroll 25 patients aged 20–80 years with Fontaine classification Stage III or IV, who will undergo BM-MNC implantation. The primary endpoint is the improvement in skin perfusion pressure of the target limb 180 days after BM-MNC implantation, whereas secondary endpoints are improvements in rest pain or ulcer size. We will also investigate rates of major or minor amputation, survival, and adverse events during follow-up.

Conclusions: BM-MNC implantation is expected to be an efficacious and feasible treatment for patients with CLTI caused by TAO.

Comparing the efficacy and safety of endovascular therapy versus surgical revascularization for critical limb-threatening ischemia: A systematic review and Meta-analysis

INTRODUCTION

Critical limb-threatening ischemia (CLTI) is a severe manifestation of peripheral artery disease (PAD) that can lead to limb amputation and significantly reduce quality of life. In addition to guideline-directed medical therapy (GDMT), endovascular therapy and surgical revascularization are the two revascularization options for CLTI. In recent years, there has been an ongoing debate about the best approach for CLTI patients. The purpose of this meta-analysis is to examine the current evidence and compare the clinical outcomes of endovascular therapy and surgical revascularization for CLTI.

METHODS

We conducted a systematic search of electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) for studies comparing the outcomes of endovascular therapy versus surgery in patients with CLTI. The primary outcomes were major adverse limb events (MALE) and major adverse cardiovascular events (MACE), while secondary outcomes included risk of bleeding, wound complications, readmission, unplanned reoperation, acute renal failure, and length of hospital stay. Pooled data was analyzed using the fixed-effect model or the random-effect model in Review Manager 5.3. The Newcastle-Ottawa Scale and Cochrane risk of bias assessment tool were used to assess the bias of included studies.

RESULTS

A total of 16 studies (47,609 patients) were included in this meta-analysis. The overall effect favors surgery over endovascular intervention in terms of MALE [odds ratio (OR) 1.13, 95% CI (1.01-1.28), P = 0.04]. Endovascular therapy is associated with lower MACE rates compared to surgery [OR 0.62, 95% CI (0.51-0.76), P < 0.00001]. Furthermore, the risk of bleeding, wound complications, readmission, unplanned reoperation, acute renal failure as well as the length of hospital stay was lower for endovascular intervention. Finally, there was no statistically significant difference in 30-day mortality between the two groups [OR 0.94, 95% CI 0.79-1.12, P = 0.52; Fig. 3i], and the pooled studies were homogeneous [P = 0.39; I2 = 5%].

CONCLUSION

Surgery may be the preferred treatment option for CLTI patients, as it is associated with a lower risk of MALE than endovascular therapy. However, endovascular therapy may be associated with a lower risk of MACE and lower rates of bleeding, wound complications, readmission, unplanned reoperation, acute renal failure, and shorter hospital stays. There was no statistically significant difference in 30-day mortality between the two groups. Ultimately, the decision to use endovascular therapy or surgery as the primary treatment strategy should be based on a multi-disciplinary team approach with careful consideration of patient characteristics and anatomy.

The "Direct tip injection in occlusive lesions (DIOL)" fashion

Background

The successful intervention for peripheral artery disease is limited by complex chronic total occlusions (CTOs). During CTO wiring, without the use of intravascular or extravascular ultrasound, the guidewire position is unclear, except for calcified lesions showing the vessel path. To solve this problem, we propose a novel guidewire crossing with plaque modification method for complex occlusive lesions, named the “Direct tip Injection in Occlusive Lesions (DIOL)” fashion.

Main text

The “DIOL” fashion utilizes the hydraulic pressure of tip injection with a general contrast media through a microcatheter or an over-the-wire balloon catheter within CTOs. The purposes of this technique are 1) to visualize the “vessel road” of the occlusion from expanding a microchannel, subintimal, intramedial, and periadventitial space with contrast agent and 2) to modify plaques within CTO to advance CTO devices safely and easily. This technique creates dissections by hydraulic pressure. Antegrade-DIOL may create dissections which extend to and compress a distal lumen, especially in below-the-knee arteries. A gentle tip injection with smaller contrast volume (1–2 ml) should be used to confirm the tip position which is inside or outside of a vessel. On the other hand, retrograde-DIOL is used with a forceful tip injection of moderate contrast volume up to 5-ml to visualize vessel tracks and to modify the plaques to facilitate the crossing of CTO devices. Case-1 involved a severe claudicant due to right superficial femoral artery occlusion. After the conventional bidirectional subintimal procedure failed, we performed two times of retrograde-DIOL fashion, and the bidirectional subintimal planes were successfully connected. After two stents implantation, a sufficient flow was achieved without complications and restenosis for two years. Case-2 involved multiple wounds in the heel due to ischemia caused by posterior tibial arterial occlusion. After the conventional bidirectional approach failed, retrograde-DIOL was performed and retrograde guidewire successfully crossed the CTO, and direct blood flow to the wounds was obtained after balloon angioplasty. The wounds heeled four months after the procedure without reintervention.

Conclusions

The DIOL fashion is a useful and effective method to facilitate CTO treatment.