Infrapopliteal Surgical and Endovascular Intervention.

Infrapopliteal revascularization is generally performed for patients with chronic limb-threatening ischemia. As with revascularization in other fields, the indications for endovascular treatment (EVT) have expanded in recent years due to advances in endovascular devices and techniques. However, the optimal revascularization method must be selected based on (1) patient risk, (2) limb severity, and (3) anatomical pattern of disease. Therefore, vascular surgeons need to understand the characteristics of EVT and surgical treatment and improve their technical skills in both procedures. Here is an overview of the current methods of revascularization. (This is a translation of Jpn J Vasc Surg 2024; 33: 61-65).

Clinical Outcomes After Distal Bypass in Patients With Chronic Limb-Threatening Ischemia due to Connective Tissue Disease.

OBJECTIVES: Chronic limb-threatening ischemia (CLTI) is mostly caused by arteriosclerosis, but is sometimes due to connective tissue disease. However, there is a limited knowledge of clinical outcomes of patients with CLTI with connective tissue disease. The objective of the study was to assess outcomes after distal bypass in these patients using global vascular guidelines. MATERIAL AND METHODS: Data from distal bypasses performed for CLTI at a single center from 2014 to 2023 were evaluated retrospectively. Clinical outcomes after distal bypass were compared for patients with CLTI with arteriosclerosis (AS group) and those with connective tissue disease (CD group). The primary endpoints were limb salvage and wound healing. RESULTS: Of the 282 distal bypasses performed for 222 patients with CLTI, 22 were conducted for 21 patients with connective tissue disease (CD group). The connective tissue disease was progressive systemic scleroderma (n = 11 patients), pemphigoid diseases (n = 2), polyarteritis nodosa (n = 2), rheumatoid arthritis (n = 2), and others (n = 4). Compared with the AS group, the CD group included more females (P = .007) and had greater oral steroid use (P < .001) and a higher Global Limb Anatomical Staging System (GLASS) inframalleolar (IM) modifier P2 (P < .001). The mean follow-up period of the whole cohort was 27 ± 22 months with no significant difference between the groups (P = .25), and 22 limbs required major amputation during this period. The 2-year limb salvage rate was significantly lower in the CD group compared to the AS group (75% vs 94%, P = .020). Wound healing was achieved in 220 (78%) limbs, and the 12-month wound healing rate was significantly lower in the CD group (52% vs 86%, P = .006). CONCLUSION: The low 2-year limb salvage and 12-month wound healing rates in patients with CLTI with connective tissue disease indicate that distal bypass may be challenging in these patients.

Outcomes after Endovascular Revascularization for Chronic Limb Threatening Ischemia from the only Vascular Quality Initiative (VQI) Center in Asia.

INTRODUCTION: This study compares chronic limb-threatening ischemia (CLTI) disease characteristics and endovascular revascularization outcomes in a multi-ethnic Asian cohort versus their North American counterparts. METHODS: The Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) registry database from the first and currently the only VQI center in Asia was reviewed to identify patients with CLTI who underwent endovascular revascularization between July 2019 and April 2024. Standardized VQI reporting variables were compared against benchmarks derived from all participating centers in North America. RESULTS: 2862 endovascular revascularization procedures from our center were benchmarked against 129347 procedures from 406 North American centers. Our cohort had a higher burden of comorbidities (diabetes mellitus, end-stage renal disease, cardiac disease) and presented with more advanced Wound, Ischemia, and Foot Infection (WIfI) stages. Our patients had more heavily calcified and longer (14.8 cm vs. 6.0 cm) diseased vessels with higher prevalence of multi-level (87% vs 54.6%), infrapopliteal (52.6% vs 38.9%) and inframalleolar (9.6% vs 2.4%) disease. Rates of technical success (92.7% vs 93%) and symptom improvement (39.1% vs 40.4%) were comparable between cohorts. However, 1-year mortality rates (28.9% vs 25.1%) and major amputation rates (13.3% vs 7.8%) were significantly higher. CONCLUSION: Short term outcomes of technical success and symptom relief in our center were comparable to benchmark North American outcomes despite having a cohort with more diseased vessels, higher WIfI stages and comorbidities. However, this cohort fared worse in longer term outcomes of 1-year mortality and major amputation rates. Further studies are required to elucidate the causes to improve these outcomes.

Percutaneous Deep Venous Arterialization by Balloon Angioplasty without Stent Implantation for Patients with Chronic Limb-Threatening Ischemia Undergoing Hemodialysis: A Retrospective Cohort, Single-Center, Single-Arm Study.

PURPOSE: This retrospective, single-center study aimed to determine the efficacy of percutaneous deep venous arterialization in patients on hemodialysis with chronic limb-threatening ischemia. MATERIALS AND METHODS: Twenty-one consecutive limbs on hemodialysis with chronic limb-threatening ischemia were treated with percutaneous deep venous arterialization using balloon angioplasty following a failed pedal arterial reconstruction between May 2021 and June 2022. An arteriovenous fistula near the ankle joint was created to ensure sufficient venous flow reversal to the pedal veins. In case of occlusion of the tibial artery, a guidewire was advanced (subintimal) to the ankle joint vicinity was technically important. The primary outcome measures were the 6-month complete wound healing and freedom from major amputation rates; the secondary outcome measure was the 6-month amputation-free survival. RESULTS: Occlusion of all pedal arteries was observed in 17 limbs (81.0%). Arteriovenous fistulas were predominantly created at the distal portions of the posterior tibial artery and vein in 18 limbs (85.7%). No extravasation at the fistulas was observed. Re-intervention was required in 16 limbs (76.2%) due to tibial artery or deep vein occlusion. The 6-month complete wound healing rate was 42.9% (nine limbs), with a median healing time of 85 days (interquartile range: 58-151 days). The 6-month freedom from major amputation and amputation-free survival rates were 90.5% (19 limbs) and 61.9% (13 limbs), respectively. CONCLUSION: Balloon angioplasty without stent implantation for percutaneous deep venous arterialization is promising for improving the complete wound healing and amputation-free survival rates after pedal artery reconstruction failure. LEVEL OF EVIDENCE: Level 3b, retrospective cohort study.

Allogenic Vertebral Body Adherent Mesenchymal Stromal Cells Promote Muscle Recovery in Diabetic Mouse Model of Limb Ischemia.

BACKGROUND: Chronic limb threatening ischemia (CLTI) carries a significant risk for amputation especially in diabetic patients with poor options for revascularization. Phase I trials have demonstrated efficacy of allogeneic mesenchymal stromal cells (MSC) in treating diabetic CLTI. Vertebral bone adherent mesenchymal stromal cells (vBA-MSC) are derived from vertebral bodies of deceased organ donors which offer the distinct advantage of providing a 1,000x greater yield compared to that of living donor bone aspiration. This study describes the effects of intramuscular injection of allogenic vBA-MSC in promoting limb perfusion and muscle recovery in a diabetic CLTI mouse model. METHODS: A CLTI mouse model was created through unilateral ligation of the femoral artery in male polygenic diabetic TALLYHO mice. Treated mice were injected with vBA-MSC into the gracilis muscle of the ischemic limb 7 days post ligation. Gastrocnemius or tibialis muscle was assessed post-mortem for fibrosis by collagen staining, capillary density via immunohistochemistry, and mRNA by quantitative real time PCR. Laser Doppler perfusion imaging and plantar flexion muscle testing were performed to quantify changes in limb perfusion and muscle function. RESULTS: Compared to vehicle control, treated mice demonstrated indicators of muscle recovery including decreased fibrosis, increased perfusion, muscle torque, and angiogenesis. PCR analysis of muscle obtained 7- and 30-days post vBA-MSC injection showed an upregulation in expression of MyoD1 (p = 0.03) and MyH3 (p = 0.008) mRNA representing muscle regeneration, VEGF-A (p = 0.002 ; p = 0.004) signifying angiogenesis as well as IL-10 (p < 0.001), T regulatory cell marker Foxp3 (p = 0.04), and M2-biased macrophage marker Mrc1 (CD206) (p = 0.02). CONCLUSIONS: These findings indicate human allogeneic vBA-MSC ameliorate ischemic muscle damage and rescue muscle function. These results in a murine model will enable further studies to develop potential therapies for diabetic CLTI patients.

Free Flap Limb Salvage and Ulcer Recurrence in Chronic Limb-threatening Ischemia.

Free flap transfer is a well-established treatment for foot reconstruction in patients with chronic limb-threatening ischemia (CLTI) and can achieve prolonged amputation-free survival. However, reports on ulcer recurrence after free flap transfer are scarce, with most focusing on trauma patients. Therefore, we retrospectively reviewed patients with CLTI who underwent free flap reconstruction at our institution over a 17-year period. Patient characteristics, ulcer recurrence rates, activity level, and variables associated with ulcer recurrence were investigated in patients who met the following criteria: successful reconstructive surgery, complete wound healing, and at least 1 year of follow-up. Free flap foot reconstruction was performed in 42 patients (92.9% male, 7.1% female; mean age 57.1 years, range 37-81 years). Among them, 39 patients (92.9%) had diabetes mellitus, 15 (35.7%) had critical limb ischemia, and 15 (35.7%) had end-stage renal disease/hemodialysis. Mean postoperative follow-up was 60.5 (range 12.0-208.0) months. The 5-year primary ulcer recurrence-free survival rate was 48.7%. High activity level and selection of the posterior tibial artery as the recipient artery were significantly associated with ulcer recurrence [hazard ratio, 3.59 and 9.81; P = .046 and P < .001, respectively]. Activity levels were not significantly different before and 1 year after surgery. In conclusion, survival analysis revealed that ulcer recurrence is most likely to occur within the first 2 years after surgery. Although recurrence occurred in approximately half of the patients, most patients maintained activity levels comparable to their preoperative levels.

The Use of Autologous Cell Therapy in Diabetic Patients with Chronic Limb-Threatening Ischemia.

Autologous cell therapy (ACT) is primarily used in diabetic patients with chronic limb-threatening ischemia (CLTI) who are not candidates for standard revascularization. According to current research, this therapy has been shown in some studies to be effective in improving ischemia parameters, decreasing the major amputation rate, and in foot ulcer healing. This review critically evaluates the efficacy of ACT in patients with no-option CLTI, discusses the use of mononuclear and mesenchymal stem cells, and compares the route of delivery of ACT. In addition to ACT, we also describe the use of new revascularization strategies, e.g., nanodiscs, microbeads, and epigenetics, that could enhance the therapeutic effect. The main aim is to summarize new findings on subcellular and molecular levels with the clinical aspects of ACT.

Consumption of different types of meat and the risk of chronic limb-threatening ischemia: the Singapore Chinese Health Study.

BACKGROUND: Although red meat consumption has been associated with risk of atherosclerotic coronary artery disease and stroke, no prospective study has examined this with the risk of chronic limb-threatening ischemia (CLTI). METHODS: In a prospective study of 63,257 Chinese in Singapore, who were aged 45-74 years old at recruitment, diet was assessed via a validated semi-quantitative food frequency questionnaire. Incident CLTI cases were ascertained via linkage with nationwide hospital records for lower extremity amputation or angioplasty for peripheral arterial disease. Multivariable Cox models were used to examine associations between quartiles of meat intake and CLTI risk. RESULTS: After a mean follow-up of 18.8 years, there were 1069 cases of CLTI. Higher intake of red meat intake was associated with increased risk of CLTI in a stepwise manner. Comparing extreme quartiles of red meat intake, the hazard ratio (HR) for the association with CLTI risk was 1.24 [95% confidence interval (CI) = 1.03-1.49; P-trend = 0.02]. In stratified analysis, red meat intake had a stronger association with CLTI risk among those without diabetes [HR (95% CI) comparing extreme quartiles = 1.41 (1.10-1.80); P-trend = 0.03] than among those with diabetes at baseline [HR (95% CI) comparing extreme quartiles = 1.04 (0.79-1.38); P-trend = 0.05] (P-interaction = 0.03). Otherwise, the associations were not different by sex, BMI, smoking status, hypertension, alcohol consumption, or history of cardiovascular diseases. Using a theoretical model in substitution analysis that substituted three servings per week of red meat with poultry or fish/shellfish, the relative risk of CLTI was reduced by 13-14%. CONCLUSIONS: Consumption of red meat was associated with higher CLTI risk in this Asian cohort. Substituting red meat with poultry or fish/shellfish may reduce this risk.

Prospective Multi-Center Longitudinal Study to Validate Accuracy of the Global Anatomic Staging System (GLASS) Score in Predicting Major Acute Limb Events in Patients With Chronic Limb Threatening Ischemia Undergoing Endovascular Intervention: The PROMOTE-GLASS Study Protocol.

INTRODUCTION: Developed by the Global Vascular Guidelines committee, the Global Limb Anatomic Staging System (GLASS) is an angiographic scoring system used for quantifying infrainguinal disease extent and predicting treatment success with endovascular techniques (EVT). Currently, no other risk prediction model is available for patients with chronic limb threatening ischemia (CLTI) undergoing EVT. GLASS' validation and adoption outside academic institutions for research are limited. Thus, this longitudinal multicenter prospective study aims to examine GLASS' validity and reliability in predicting major acute limb events and overall survival (OS) in patients with CLTI undergoing EVT. METHODS AND ANALYSIS: This prospective, international, multicenter, observational study will include patients with CLTI undergoing EVT (PROMOTE-GLASS) (ClinicalTrials.gov; ID: NCT06186544) identified through routine clinical referrals and emergency visits to vascular units in participating centers. Only patients who are referred for EVT will be recruited. The primary outcomes are immediate technical success, immediate technical failure, and 1-year limb base patency. The secondary outcomes are major adverse limb events, major lower limb amputation, and OS in patients presenting with CLTI who undergo EVT up to 1 year after the procedure. Clinical and imaging data will be analyzed at the end of follow-up to validate risk prediction. This protocol outlines our approach for identifying cases, GLASS score calculation, outcome measures assessment, and a statistical analysis plan. ANTICIPATED IMPLICATIONS: PROMOTE-GLASS holds significant implications and can potentially revolutionize clinical decision-making by assisting clinicians in identifying patients who are likely to benefit from EVT. Ultimately, reduce the need for more invasive procedures and improve patient outcomes. Furthermore, PROMOTE-GLASS can provide useful information, including patient selection, for future randomized controlled trials (RCTs) investigating EVT for CLTI. PROMOTE-GLASS anticipated implications on the vascular community are rooted in its potential to improve patient care, inform future research, and address limitations in existing literature regarding CLTI treatment outcomes.

Progressive Acute Lower Extremity Ischemia Resulting From Cardiac Myxoma Embolization: A Case Report.

Cardiac myxomas are the most common primary benign tumors of the heart. The occlusion of peripheral arteries and complete obstruction of the abdominal aorta by a tumor embolus presents with distinct clinical manifestations. Herein, we present the case of a 38-year-old male with acute paresthesia, muscle weakness, erythematous, and violaceous changes in skin color localized to the dorsum of the left forefoot initially treated as cutaneous vasculitis. Further studies revealed the total occlusion of the terminal abdominal aorta by a saddle embolus from a cardiac myxoma. A multidisciplinary team consisting of cardiothoracic and vascular surgeons were involved in treating the patient, which resulted in full resolution of the case. This paper details the progression of acute bilateral limb ischemia to chronic limb threatening ischemia resulting from the total occlusion of the terminal abdominal aorta by a saddle embolus.

Outcomes of a Multidisciplinary Vascular Practice: 12-Month Amputation-Free Survival and Beyond in Patients With Chronic Limb-Threatening Ischemia.

OBJECTIVE: There is great variability in the treatment of chronic limb-threatening ischemia, including the practice paradigm, vascular provider specialty, devices utilized, and experience with advanced open and/or endovascular treatments, among other factors. Our unique practice consists of patient-centered, clinically oriented Interventional Radiologists and Vascular Surgeons, with treatments being performed in Office Interventional Suites (OIS), Ambulatory surgery center (ASC), and hospital inpatient/outpatient settings. We evaluate our results, centered on major amputation rates while comparing case complexity and rates with previously published data. METHODS: A retrospective review was performed of all Rutherford 4, 5, and 6 patients who underwent treatment in our practice from 2015 to 2021. Baseline patient characteristics, complexity of lesions, and major amputation rates were collected. Patients with more complex diseases or requiring re-interventions were openly discussed in multidisciplinary fashion to determine the group's approach to revascularization. Limb salvage, clinically driven target lesion revascularization (TLR), repeat interventions, length of follow-up, and mortality were assessed. RESULTS: Treatment was performed in 829 limbs in 351 females and 478 males, with chronic limb-threatening ischemia. Of the 829 cases, 541 cases had at least 1 chronic total occlusion (CTO), including 115 limbs with 2 CTOs and 24 limbs with 3 CTOs with 63.5% of cases requiring multilevel intervention. One year mortality rate was 6.2% with a major lower extremity amputation rate of 2.3% with a mean length of follow-up of 22.3 months. One-year freedom from clinically driven TLR rate was 78.7% with repeat intervention in 163 cases within 12 months. Over the course of the study, within the femoropopliteal stent subset, there was a significant increase in time to reintervention when newer stent technologies were utilized such as woven nitinol and drug-eluting technology (p=0.03). The overall 1-year amputation-free survival (AFS) was 91.5. CONCLUSIONS: Multidisciplinary approach with surgical and endovascular treatment may provide patients with the best chance of AFS. CLINICAL IMPACT: Real world practice of critical limb-threatening ischemia in a multidisciplinary practice demonstrates favorable outcomes for patients with the best reported one year major amputation free survival in a population this large. A strong clinical practice based on close routine follow up and arterial duplex monitoring is a major contributing factor, as well as utilization of the latest technology in drug eluting stents and drug coated balloons for best patient outcomes. We hope this study provides other practices with a guideline for establishing or modifying their practice to attain the best procedural and clinical outcomes.

Combining Tibial Cortex Transverse Transport (TTT) and Endovascular Therapy (EVT) for Limb Salvage in Chronic Limb-Threatening Ischemia.

OBJECTIVE: The clinical management of patients with chronic limb-threatening ischemia (CLTI) faces great challenges. Enhancing wound healing and limb preservation rates in this cohort is a critical objective. This study investigates the effectiveness of combining tibial cortex transverse transport (TTT) and endovascular therapy (EVT) for the treatment of patients with severe CLTI. We aim to evaluate the therapeutic results of this combined approach on the specified patient group. METHODS: We conducted a retrospective study to compare EVT with the combination of TTT and EVT in patients (Rutherford category 5 and above) with CLTI at Guangxi Medical University's First Affiliated Hospital from June 2017 to June 2023. This cohort was subjected to a follow-up period ranging from a minimum of 6 months to a maximum of 12 months. The primary outcome measures included amputation-free survival (AFS) (avoidance of above-ankle amputation or death from any cause), overall mortality, limb salvage rates, wound healing efficiency, and the technical efficacy of the applied treatments. A variety of statistical analyses including chi-square tests, Fisher's exact tests, and Pearson's and Spearman's correlation analyses. RESULTS: In this study, 131 patients with CLTI were included: 76 in the control group receiving only EVT treatment and 55 in the TTT + EVT group. The two groups were matched on demographic and clinical characteristics. In the TTT + EVT group, after more than 6 months of follow-up, 85.5% of patients achieved AFS, and wound healing was observed in 54.5% (30 of 55 patients). After more than 12 months of follow-up, 81.9% achieved AFS, with wound healing in 32 patients. Furthermore, after more than 24 months, 74.2% of patients remained amputation-free, with wound healing in all surviving patients. In the control group, after more than 6 months of follow-up, 72.4% of patients achieved AFS, and wound healing was observed in 51.3% (39 of 96 patients). After more than 12 months, 48.9% achieved AFS, with wound healing in 21 patients. CONCLUSION: We found that combining therapy of TTT and EVT is safe and can be successfully administered in patients with CLTI and it enhances wound healing and AFS.

Hemoglobin A1c Levels Are Related to Patency and Adverse Limb Events in Diabetics After Revascularization.

OBJECTIVE: Poor glycemic control in the perioperative period has been reported to be associated with early and late major adverse limb events (MALE). However, these studies were mostly from large databases or lacked long-term outcomes. We examined the long-term effects of high hemoglobin A1c (HbA1c) level on patency, MALE, limb salvage (LS) and survival after lower extremity revascularization procedures in diabetic patients. METHODS: Patients with diabetes who had revascularization for Rutherford class 3-6 ischemia between May 2002 and December 2018 were identified. Patients with HbA1c≤7% were compared to HbA1c>7% for patency, MALE, survival, LS and amputation-free survival (AFS). RESULTS: Of 706 patients, 699 had HbA1c data (775 limbs), with 311 (357 limbs) in HbA1c≤7%, and 388 (418 limbs) in HbA1c>7% groups. Patients with HbA1c>7% were younger (69.9±10.2 vs 71.7±9.5, P=0.011), had higher lipid levels, insulin use (70% vs 49%, P<0.01), ASA 4, and had lower prevalence of chronic kidney disease (CKD) (32%vs41%, P=0.023). HbA1c>7% patients were more likely to present with chronic limb-threatening ischemia (CLTI) (79% vs 72%,P=0.019) and undergo infrapopliteal interventions (49% vs 42%, P=0.005), with no difference in anatomic complexity (TASC C/D, 75% vs 77%, p=0.72) or type of revascularization (24% vs 18% Open, 66% vs 70% EV, 10% vs 12% Hybrid, p=0.236). Patency and freedom from MALE were significantly lower in patients with HbA1c>7% for infra-inguinal revascularizations, whereas AFS and overall survival were similar. In patients with CLTI, LS rates at five years were significantly lower in patients undergoing open revascularization (HbA1c>7%: 64%±6%vs HbA1c<7%:86%±5%, P=0.020), whereas it was similar after endovascular interventions (HbA1c>7%:79%±4% vs HbA1c<7%:77%±3%, p=0.631). Seventy patients with HbA1c>7% lost limbs vs 38 patients with HbA1c≤7% (P=0.007). In multivariate analysis, HbA1c was significantly associated with primary patency. HbA1c, insulin use, level of intervention, and ACEI use were associated with MALE. CONCLUSIONS: Perioperative HbA1c>7% is associated with poorer patency rates, and increased MALE especially at the infra-inguinal level revascularization in diabetics, with no significant impact on survival. Limb salvage is impacted after open, but not after endovascular revascularization.

Early Tibial Vessel Recoil Following Treatment With the Bare Temporary Spur Stent System: Results From the DEEPER OUS Vessel Recoil Substudy.

PURPOSE: Vessel recoil is a common phenomenon occurring in the tibial vessels following balloon angioplasty. This study examined the occurrence and short-term impact of acute vessel recoil in a subset of patients treated with retrievable scaffold therapy (RST) via the Spur Peripheral Retrievable Scaffold System (Spur). METHODS: Patients with tibial disease underwent angiography immediately following RST, and then 15 minutes post-treatment. Vessel recoil was defined as a ≥10% decrease in lumen diameter after 15 minutes. Recoil was further analyzed by late lumen loss method, subsegmental late lumen loss method, and smallest segment to same segment method. Patient and vessel characteristics were evaluated. Functional recoil (acute vessel spasm), defined as no significant change in minimal lumen diameter (MLD) at baseline compared with 15 minutes post-treatment, was also evaluated. RESULTS: Of the 38 patients (40 lesions; 33 men [87%]; mean [SD] age 75.3 [8.2] years; 26 (68.4%) with diabetes mellitus); recoil was noted in 42.5% of vessels. Prior to treatment, 13 lesions (32.5%) were total occlusions, the mean lesion length was 64.7±30.4 mm, and 27.5% (11/40) were moderate or severely calcified. Mean treated lesion length was 97.8±39.6 mm. For lesions evaluable by duplex ultrasound, 86.7% of vessels (26/30) were patent at 6 months. There was no significant difference in patency between lesions with recoil and lesions without recoil (81.8% vs 89.5%); there was a trend toward patency in the non-recoil group. Two lesions had functional recoil (acute vessel spasm) and were patent at 6 months. There was no statistically significant correlation of recoil to comorbidities or lesion characteristics, including calcification, for which there was also no correlation to patency. CONCLUSION: Vessel recoil was noted in 42.5% of vessels treated with RST, whereas previous published rates with balloon angioplasty demonstrated vessel recoil up to 97%, suggesting that RST may impact vessel recoil. This exploratory study did not demonstrate a correlation between vessel recoil and patency at 6 months. CLINICAL IMPACT: Retrievable scaffold therapy may replace scoring devices and cutting devices for vessel preparation before definite (drug) therapy. Retrievable scaffold therapy supplements already established vessel preparation strategies in order to follow the concept of leaving nothing behaind. A temporary retrievable scaffold for changing vessel compliance and potentially releasing antiproliferative drugs represents a new interventional concept.

Can wound blush be used as an indicator for termination of endovascular procedures in chronic limb-threatening ischemia patients?

INTRODUCTION: Predicting the outcomes of endovascular revascularization of chronic limb-threatening ischemia (CLTI) patients with foot wounds can be challenging. Angiographic wound blush (WB) assessment has been found to be a helpful tool to assess wound perfusion. The aim of this study is to evaluate WB during endovascular revascularization of CLTI patients and its effects on treatment outcomes. METHODS: This prospective study included all CLTI patients with foot wounds who underwent successful endovascular revascularization of infrainguinal arterial disease between 2019 and 2021. Patients were grouped according to the WB status into positive WB (group A) and negative WB (group B). Both groups were compared for demographics, comorbidities, clinical picture, and 12-month limb-based patency (LBP) and amputation-free survival (AFS) rates. RESULTS: The study included 69 patients of Rutherford classes 5 (46.4%) and 6 (53.6%), with the main arterial lesion located at the femoropopliteal (58%) or infrapopliteal (42%) segments. Completion angiography showed positive WB in 38 (55.1%) patients and negative WB in 31 (44.9%) patients. Both groups were comparable regarding patient presentation, site of the main arterial lesion, and distribution of foot lesions in relation to the feeding artery. The overall 12-month LBP and AFS rates were 21.7% and 39.1%, respectively, with significantly better rates in group A than in group B (LBP, 31.6% vs 9.7%, p = 0.001 and AFS, 54.1% vs 22.2%, p = 0.006, respectively). Successful angiosome-based direct flow to the foot was achieved in 38 patients (55.1%), resulting in significantly better 12-month AFS rates than those with indirect revascularization (54.8% vs 26.3%, p = 0.036, respectively), despite the comparable 12-LBP rates between the direct and indirect revascularization groups (29% vs 15.8%, p = 0.133, respectively). Multivariate logistic regression analysis identified smoking as a significant predictor of a major amputation, whereas positive WB and successful direct revascularization were significant predictors of limb salvage. CONCLUSIONS: WB can serve as a predictor for AFS and LBP during endovascular revascularization of CLTI patients with foot wounds. A positive WB may guide the decision to conclude an endovascular procedure, potentially avoiding unnecessary complicated maneuvers to recanalize more vessels. Conversely, a negative WB may suggest the need for further revascularization attempts to augment wound perfusion and healing.

Clinical outcomes of endovascular therapy for chronic limb-threatening ischemia in renal transplant recipients.

Endovascular treatment (EVT) for peripheral artery disease in patients with chronic limb-threatening ischemia (CLTI) is a common practice in contemporary medicine and its effectiveness is widely acknowledged. However, refractory ulcers can occasionally be encountered, particularly in patients who underwent renal transplantation (RT), even after successful EVT. To date, there have been no data on prognosis reported following EVT for CLTI in RT recipients. We included all RT recipients who underwent EVT in our hospital between 2010 and 2022. We analyzed data from 43 limbs with ischemic ulcerations classified as Rutherford class 5 or 6, which were managed solely with EVT (i.e., no bypass surgery was performed). The primary and secondary outcomes of our study were the incidence of complete wound healing and major adverse limb events (MALE), including clinically driven target vessel revascularization, major amputation, and all-cause death. The median follow-up was 31 months. The mean age of the study population was 64.7 ± 8.7 years, with predominantly male participants (79.1%). The overall wound healing rate was 34.9%. Kaplan-Meier curve revealed that wound healing rates at 1 and 3 years were 33.6% and 40.9%, respectively. The wound healing rates of RT recipients who underwent EVT for CLTI were found to be less than satisfactory.

Competing risk analysis to estimate amputation incidence and risk in lower-extremity peripheral artery disease.

Background: Patients with peripheral artery disease face high amputation and mortality risk. When assessing vascular outcomes, consideration of mortality as a competing risk is not routine. We hypothesize standard time-to-event methods will overestimate major amputation risk in chronic limb-threatening ischemia (CLTI) and non-CLTI. Methods: Patients undergoing peripheral vascular intervention from 2017 to 2018 were abstracted from the Vascular Quality Initiative registry and stratified by mean age (⩾ 75 vs < 75 years). Mortality and amputation data were obtained from Medicare claims. The 2-year cumulative incidence function (CIF) and risk of major amputation from standard time-to-event analysis (1 - Kaplan-Meier and Cox regression) were compared with competing risk analysis (Aalen-Johansen and Fine-Gray model) in CLTI and non-CLTI. Results: A total of 7273 patients with CLTI and 5095 with non-CLTI were included. At 2-year follow up, 13.1% of patients underwent major amputation and 33.4% died without major amputation in the CLTI cohort; 1.3% and 10.7%, respectively, in the non-CLTI cohort. In CLTI, standard time-to-event analysis overestimated the 2-year CIF of major amputation by 20.5% and 13.7%, respectively, in patients ⩾ 75 and < 75 years old compared with competing risk analysis. The standard Cox regression overestimated adjusted 2-year major amputation risk in patients ⩾ 75 versus < 75 years old by 7.0%. In non-CLTI, the CIF was overestimated by 7.1% in patients ⩾ 75 years, and the adjusted risk was overestimated by 5.1% compared with competing risk analysis. Conclusions: Standard time-to-event analysis overestimates the incidence and risk of major amputation, especially in CLTI. Competing risk analyses are alternative approaches to estimate accurately amputation risk in vascular outcomes research.

Exploring Prognostic Implications of Race and Ethnicity in Patients With Peripheral Arterial Disease.

INTRODUCTION: Significant health inequalities in major adverse limb events exist. Ethnically minoritized groups are more prone to have a major adverse event following peripheral vascular interventions. This systematic review and meta-analysis aimed to describe the postoperative implications of racial and ethnic status on clinical outcomes following vascular interventions for claudication and chronic limb-threatening ischemia. METHODS: Searches were conducted across seven databases from inception to June 2021 and were updated in October 2022 to identify studies reporting claudication or chronic limb-threatening ischemia in patients who underwent open, endovascular, or hybrid procedures. Studies with documented racial and ethnic status and associated clinical outcomes were selected. Extracted data included demographic and clinical characteristics, vascular interventions, and measured outcomes associated with race or ethnicity. Meta-analyses were performed using random-effect models to report pooled odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Seventeen studies evaluating the impact of Black versus White patients undergoing amputation as a primary intervention were combined in a meta-analysis, revealing that Black patients had a higher incidence of amputations as a primary intervention than White patients (OR: 1.91, 95% CI: 1.61-2.27). Another meta-analysis demonstrated that Black patients had significantly higher rates of amputation after revascularization (OR: 1.56, 95% CI: 1.28-1.89). Furthermore, multiple trends were demonstrated in the secondary outcomes evaluated. CONCLUSIONS: Our findings suggest that Black patients undergo primary major amputation at a significantly higher rate than White patients, with similar trends seen among Hispanic and First Nations patients. Black patients are also significantly more likely to be subjected to amputation following attempts at revascularization when compared to White patients.

Impact of Peripheral Angioplasty on Wound Oxygenation and Healing in Patients with Chronic Limb-Threatening Ischemia Measured by Near-Infrared Spectroscopy.

Managing chronic limb-threatening ischemia (CLTI) is challenging due to difficulties in assessing tissue oxygen saturation in ulcers. Near-infrared spectroscopy (NIRS) is a non-invasive method for measuring tissue oxygen saturation (StO2). This study evaluated the effects of endovascular treatment (EVT) on StO2 and wound healing in CLTI patients, comparing NIRS to standard ankle-brachial index (ABI) measurements. Using the Duesseldorf PTA Registry, 43 CLTI patients were analyzed: 27 underwent EVT, and 16 received conservative treatment. ABI assessed macrocirculation, while NIRS measured wound, wound area, and mean foot StO2 at baseline, post-EVT, and four-month follow-up. Wound severity was classified by wound area and wound, ischemia, and foot infection (WIfI) score. Wound StO2 increased significantly (median (interquartile range (IQR)), 38 (49.3) to 60 (34.5)%, p = 0.004), as did wound area StO2 (median (IQR), 70.9 (21.6) to 72.8 (18.3)%, p < 0.001), with no significant changes in the control group by four-month follow-up. Wound area decreased significantly after EVT (mean ± SD, 343.1 ± 267.8 to 178.1 ± 268.5 mm2, p = 0.01) but not in the control group. Changes in wound StO2, wound area StO2, and WIfI score correlated with wound area reduction, unlike ABI. This small exploratory study shows that NIRS-measured StO2 improvements after EVT correlate with reduced wound area and WIfI scores, highlighting NIRS as a potential enhancement for CLTI wound management in addition to ABI.

Early Tissue Resection Versus Watchful Waiting After Revascularization for Chronic Limb-Threatening Ischemia: A Meta-Analysis.

No consensus or guideline has been established regarding the optimal timing of tissue resection after revascularization in patients with chronic limb-threatening ischemia (CLTI). This study aimed to compare early tissue resection and watchful waiting after revascularization regarding the outcomes of patients with CLTI. We searched PubMed, the Cochrane Library, and EMBASE for relevant randomized trials and observational studies published from their inception to May 1, 2024. In total, five articles were analyzed. The results showed that the early tissue resection group had a higher wound healing rate than the watchful waiting group (I2 = 26%, odds ratio [OR] = 2.80, 95% confidence interval [CI] 1.32 to 5.92, P = 0.007). However, the rate of major amputation was significantly higher in the early tissue resection group than in the watchful waiting group (I2 = 5%, OR = 1.48, 95% CI 1.18 to 1.86, P < 0.001), and wound recurrence rate in the early tissue resection group was relatively higher than that in the watchful waiting group (I2 = 0%, OR = 2.42, 95% CI: 0.99 to 5.93, P = 0.05). No statistical significance was found in the rate of postoperative mortality (I2 = 2%, OR = 0.99, 95% CI: 0.69 to 1.41, P = 0.94) and wound healing time (I2 = 97%, standardized mean difference = -105.92, 95% CI -232.96 to 21.13, P = 0.10) between the early tissue resection and watchful waiting groups. For patients without signs of infection, a watchful waiting strategy could reduce the risk of major amputation.