Infrapopliteal 3-Vessel Occlusive Disease Is the Only Predictor of Wound Recurrence After Complete Wound Healing via Endovascular Therapy in Patients With Chronic Limb-threatening Ischemia.

PURPOSE: To determine the predictors of wound recurrence after complete wound healing in patients with chronic limb-threatening ischemia (CLTI) who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions with consideration of IP arterial anatomic severity, including classification by the Global Limb Anatomic Staging System (GLASS). MATERIALS AND METHODS: This retrospective single-center study assessed patients with de novo CLTI limbs with tissue loss treated via EVT for IP lesions from September 2016 to May 2021. Among these patients, 149 consecutive limbs from 133 patients who achieved complete wound healing were enrolled. The Kaplan-Meier method was used to estimate the wound recurrence rate after complete wound healing. The Cox proportional hazard model was used to assess the association between baseline characteristics and wound recurrence. RESULTS: The cumulative wound recurrence rate 1 year after complete wound healing was 30%. The mean time for wound recurrence was 7±5 months. Only IP arterial anatomic characteristics remained as a predictor of wound recurrence, whereas wound status and management, including the Wound, Ischemia, and foot Infection (WIfI) clinical stage and minor amputation, were not associated with wound recurrence. Multivariate analysis revealed independent associations between wound recurrence and IP 3-vessel occlusive disease (hazard ratio, 2.97; 95% confidence interval, 1.39-6.35), but not poor below-the-ankle runoff, IP Peripheral Arterial Calcium Scoring System (PACSS) grade, and the GLASS IP grade. CONCLUSION: The only independent predictor of wound recurrence after complete wound healing via EVT in patients with CLTI was IP 3-vessel occlusive disease. CLINICAL IMPACT: In patients with chronic limb-threatening ischemia (CLTI), wound recurrence after complete wound healing remains a challenge, and studies focused exclusively on wound recurrence are still limited. The present study aimed to determine the risk factors for wound recurrence after complete wound healing in patients with CLTI who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions, with consideration of IP arterial anatomic severity for the first time. The results showed that IP 3-vessel occlusive disease was the only predictor of wound recurrence, whereas wound status/management and other arterial anatomic characteristics including WIfI clinical stages and GLASS grades were not predictors.

High Global Limb Anatomic Staging System Femoropopliteal Grade is Positively Associated with Wound Healing in Patients with Chronic Limb-Threatening Ischemia Undergoing Endovascular Therapy Only for Femoropopliteal Disease.

BACKGROUND: To investigate the prognostic impact of femoropopliteal (FP) arterial anatomic severity including classification by the global limb anatomic staging system (GLASS) on wound healing in patients with chronic limb-threatening ischemia (CLTI) who had undergone endovascular therapy (EVT) only for FP lesions. METHODS: This was a retrospective single-center study. We treated 349 consecutive de novo CLTI limbs with tissue loss from January 2017 to May 2021. Among these, 91 limbs treated via EVT only for FP lesions were enrolled. We compared the clinical background, infrapopliteal (IP)/FP arterial anatomical characteristics, and EVT results between the limbs with GLASS FP grade 1 or 2 (low GLASS FP, n = 20) and those with GLASS FP grade 3 or 4 (high GLASS FP, n = 71). The Kaplan-Meier method was used to estimate the wound healing rate. The Cox proportional hazard model was used to assess the association between baseline characteristics and wound healing. RESULTS: No patient underwent EVT for IP lesions. IP arterial anatomical characteristics did not show any significant difference between the low and high GLASS FP groups. The cumulative wound healing rate after EVT was significantly higher in the high GLASS FP group than in the low GLASS FP group (88% vs. 39% at 6 months; P < 0.001). Multivariate analysis revealed that low wound, ischemia, and foot infection (WIfI) clinical stage (stage 1 or 2) (hazard ratio [HR] 2.33; 95% confidence interval [CI] 1.32-4.17) and high GLASS FP (grade 3 or 4) (HR 5.18; 95% CI 1.99-13.51) were independent factors for wound healing. CONCLUSIONS: High GLASS FP grade was positively associated with wound healing after EVT only for FP lesions.

Impact of Antimicrobial-Resistant Bacterial and Polymicrobial Infection on Wound Healing After Minor Forefoot Amputation in Chronic Limb-Threatening Ischemia With Infection.

OBJECTIVES: This study aimed to evaluate the relationship between bacteriological findings and wound healing after minor amputation in the treatment of chronic limb-threatening ischemia (CLTI) with infection. METHODS: This single-center retrospective study analyzed 135 consecutive limbs with tissue loss and infection from 120 patients who underwent endovascular therapy (EVT) and minor forefoot amputation for CLTI with wound infection between November 2017 and August 2021. The Kaplan-Meier method was used to assess the rate of wound healing after the procedure. The Cox proportional-hazards model was used to examine the impact of bacteriological findings and baseline characteristics on wound healing. RESULTS: The wound healing rate at 6 months was 72.6%. In a multivariate analysis, in addition to hemodialysis (hazard ratio [HR]=1.73; p=0.009) and amputation above the metatarsophalangeal (MP) joint (HR=1.81; p=0.006), antimicrobial-resistant bacterial infection (HR=1.80, p=0.004) and polymicrobial infection (H=1.51; p=0.049) were predictors of delayed wound healing. CONCLUSION: Antimicrobial-resistant bacterial infection, polymicrobial infection, hemodialysis, and amputation above the MP joint were independent predictors of delayed wound healing after EVT and minor forefoot amputation in patients with CLTI and bacterial wound infection. CLINICAL IMPACT: In this single-center retrospective study, we analyzed 136 consecutive limbs with tissue loss and infection from 120 patients who underwent endovascular therapy and minor forefoot amputation for chronic limb-threatening ischemia (CLTI) with wound infection between November 2017 and August 2021. Our main findings were that antimicrobial-resistant bacterial infection, polymicrobial infection, hemodialysis, and amputation above the metatarsophalangeal joint were independent predictors of delayed wound healing after minor amputation. This is the first report of the association between bacteriological studies and wound healing in CLTI with infection, and will be of great help in the future clinical practice.

Evaluation of depth of dislocation visibility in SEM electron channeling contrast imaging in Ti-6Al-4V alloy using serial sectioning method.

In this study, we conducted a quantitative evaluation of dislocation density by scanning electron microscopy electron channeling contrast imaging for α grains of a Ti-6Al-4V alloy deformed at room temperature. The depth of visibility of dislocations is experimentally measured as 140 to 160 nm by a serial sectioning observation. This result is compared with the theoretical value and applied to evaluate dislocation density. These factors confirm that the theoretically calculated value of the depth of visibility, at 5 to 6 times the extinction distance, is valid for the hexagonal close-packed Ti alloy.

A model for predicting the time of early symptomatic restenosis after infrapopliteal angioplasty in patients with critical limb ischemia.

The objective of this study is to develop a model for predicting the time of early symptomatic (delayed or nonhealing wound) restenosis after infrapopliteal angioplasty in patients with critical limb ischemia (CLI). This is a single-center retrospective cohort study evaluating 60 de novo infrapopliteal lesions of 38 limbs in 35 patients with CLI, who underwent successful endovascular treatment (EVT) from October 2016 to December 2018 and follow-up angiography within 3 months from the procedure. Outcome measures were binary restenosis at follow-up angiography and clinical outcome at 3 months. Patient/limb/lesion characteristics were compared between the restenosis and non-restenosis groups. Angiographic restenosis predictors were assessed to develop a model for predicting the time of restenosis using multinomial logistic regression. The restenosis rate at follow-up angiography (median time, 41 days [IQR 27-58 days]) was 38% (23/60). After adjustment for covariables, longer period between EVT and follow-up angiography and lower C-reactive protein (CRP) were the predictors of angiographic restenosis. We developed a model for predicting the time of early symptomatic restenosis with a probability of 70%: "Days = 200 - 2.1 age - 13 CTO + 3.3 CRP" (R2 = 0.81, RMSE = 0.27), e.g., 80 years old, CTO (+), CRP 4.4 mg/dl: 32.2 days. The predictive model including age, CTO, and CRP might allow estimation of the period for the angiographic restenosis development.

Successful Retrieval of a Stuck Guidewire by Guiding Catheter Lock Technique in Renal Artery Stenting.

INTRODUCTION: The guiding catheter lock technique is a therapeutic technique to increase backup force of the guiding catheter in coronary artery interventions. SURGICAL TECHNIQUE: A 71 year old man presented with rapidly declining kidney function resulting from bilateral renal artery stenosis. During the renal artery stenting procedure, the 0.014" guidewire became trapped at the stent's distal edge. Although attempts were made to advance a microcatheter and balloon catheter over the trapped guidewire, these failed because of insufficient pushability of the guiding catheter. Therefore, the guiding catheter lock technique was used with a second guiding catheter, and the guidewire was successfully retrieved. DISCUSSION: The guiding catheter lock technique facilitated strong pushability to allow for successful retrieval of a stuck guidewire during renal artery stenting.