Predictors of Wound Healing Following Revascularization for Chronic Limb-Threatening Ischemia

Updates in Arterial Ulcers

Arterial ulcers are a clinical symptom of a complex array of underlying comorbid factors, namely peripheral artery disease (PAD). Chronic limb-threatening ischemia is representative of end-stage PAD. Ulcers of other etiologies can carry an arterial component, mandating recognition of risk factors, a comprehensive history and physical examination, and appropriate diagnostic testing in lower extremity ulcers. The primary therapy for arterial ulcers is re-establishment of in-line arterial flow, achieved by endovascular therapy or open revascularization. Medical management is essential to slow disease progression, and topical therapies are crucial to promote rapid ulcer closure and reduce infection risk.

Characterization of oral biomarkers during early healing at augmented dental implant sites

AIM

The aim of this study is to assess early wound healing expression of local angiogenic biomarkers following connective tissue graft (CTG) at dental implant sites.

METHODS

Twenty-eight subjects with single dental implants exhibiting a soft tissue dehiscence were included and randomly treated with CTG, either with coronally advanced flap (CAF) or with tunnel technique (TUN). Peri-implant crevicular fluid (PICF) was collected at the midfacial and midlingual aspect of the implant sites at baseline and at 3, 7, 14, 30, and 90 days after the surgical intervention. The expression of angiogenin (ANG), fibroblast growth factor-2 (FGF-2), platelet-derived growth factor (PDGF), tissue inhibitor of metalloproteinases-2 (TIMP-2), and vascular endothelial growth factor (VEGF) was investigated over a period of 3 months. Patient-reported outcomes, clinical measurements, and ultrasonography scans at multiple time points were also evaluated.

RESULTS

The longitudinal regression revealed a significant difference in the expression of VEGF and TIMP-2 between CAF- and TUN-treated sites over 3 months (p = .033 and p = .004, respectively), whereas no significant differences were observed for ANG, FGF-2 and PDGF between the two groups. At 7 days, a direct correlation was observed between ANG levels and ultrasonographic color velocity in the CAF group (p < .001) and between ANG levels and ultrasonographic color power in the TUN group (p = .028). VEGF levels and ultrasonographic mean perfused area of the CTG were significantly correlated at the 7-day time point (p < .001 for both CAF and TUN). The expression of VEGF at 7 days was directly associated with mucosal thickness gain at 1 year (p < .001 for both groups). Early TIMP-2 expression showed an inverse correlation with time to recovery (p = .002). TIMP-2 levels at 3 months exhibited inverse correlations with mean dehiscence coverage (p = .004) and the rate of complete dehiscence coverage (p = .012).

CONCLUSION

PICF biomarkers can be used to monitor early wound healing events following soft tissue grafting at implant sites. VEGF and TIMP-2 showed correlations with the 1-year clinical and volumetric outcomes, as well as with post-operative patient-reported outcomes and Doppler Ultrasonographic tissue perfusion-related parameters.

Editor's Choice - Reduction of Major Amputations after Surgery versus Endovascular Intervention: The BEST-CLI Randomised Trial

OBJECTIVE

BEST-CLI, an international randomised trial, compared an initial strategy of bypass surgery with endovascular treatment in chronic limb threatening ischaemia (CLTI). In this substudy, overall amputation rates and risk of major amputation as an initial or subsequent outcome were evaluated.

METHODS

A total of 1 830 patients were randomised to receive surgical or endovascular treatment in two parallel cohorts: patients with adequate single segment great saphenous vein (SSGSV) (n = 1 434) were assigned to cohort 1; and patients without adequate SSGSV (n = 396) were assigned to cohort 2. Differences in time to first event and number of amputations were evaluated.

RESULTS

In cohort 1, there were 410 (45.6%) total amputation events in the surgical group vs. 490 (54.4%) in the endovascular group (p = .001) during a mean follow up of 2.7 years. Approximately one in three patients underwent minor amputation after index revascularisation: 31.5% of the surgical group vs. 34.9% in the endovascular group (p = .17). Subsequent major amputation was required significantly less often in the surgical group compared with the endovascular group (15.0% vs. 25.6%; p = .002). The first amputation was major in 5.6% of patients in the surgical group and 6.0% in the endovascular group (p = .72). Major amputation was required in 10.3% (74/718) of patients in the surgical group and 14.9% (107/716) in the endovascular group (p = .008). In cohort 2, there were 199 amputation events in 132 patients (33.3%) during a mean follow up of 1.6 years: 95 (47.7%) in the surgical group vs. 104 (52.3%) in the endovascular group (p = .49). Major amputation was required in 15.2% (30/197) of patients in the surgical group and 14.1% (28/199) in the endovascular group (p = .74).

CONCLUSION

In patients with CLTI, surgical bypass with SSGSV was more effective than endovascular treatment in preventing major amputations, mainly due to a decrease in major amputations subsequent to minor amputations.

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.

[Reconstruction options for infection-related defects : Plastic surgery armamentarium]

BACKGROUND

The occurrence of infections has always been feared in all surgical disciplines. Plastic reconstructive surgery faces the challenge of treating infection-related defects on a patient-specific basis, which requires a multidisciplinary treatment concept. Satisfactory treatment success can only be achieved through radical debridement for infection cleansing, optimization of the perfusion situation paired with targeted anti-infective treatment and, if necessary, with soft tissue reconstruction by plastic surgery.

OBJECTIVE

This article presents the current possibilities of plastic and reconstructive surgery with respect to the reconstruction of infection-related defects.

MATERIAL AND METHODS

Proven and reliable strategies are presented and supplemented by promising experimental approaches.

RESULTS

Due to the often multilayered defect situation caused by infections, from the epidermis to cancellous bone, the entire armamentarium of plastic and reconstructive surgery is used for reconstruction.

CONCLUSION

The early involvement of plastic surgery in the treatment of infections and the interdisciplinary and multimodal treatment approach have proven their worth in the treatment of complex infection situations.

Oxygen Therapy to Enhance Wound Healing After Revascularization

Oxygen is one of the important factors for wound healing and infection control. The revascularization procedure is amended to correct the tissue hypoxia problem by increasing the blood flow to obtain an adequate amount of oxygen. Hypoxic wounds are still the issue in the cases of unsuccessful or incomplete revascularization. The issue needs to be clarified and confirmed by proper methods for management to achieve wound healing and prevent limb loss. Oxygen therapy may benefit in the case of remaining hypoxia or wound infection in postrevascularization.

A focused review on hyaluronic acid contained nanofiber formulations for diabetic wound healing

The significant clinical challenge presented by diabetic wounds is due to their impaired healing process and increased risk of complications. It is estimated that a foot ulcer will develop at some point in the lives of 15-25 % of diabetic patients. Serious complications, including infection and amputation, are often led to by these wounds. In the field of tissue engineering and regenerative medicine, nanofiber-based wound dressings have emerged in recent years as promising therapeutic strategies for diabetic wound healing. Hyaluronic acid (HA), among various nanofiber materials, has gained considerable attention due to its unique properties, including biocompatibility, biodegradability, and excellent moisture retention capacity. By promoting skin hydration and controlling inflammation, a crucial role in wound healing is played by HA. Wounds are also helped to heal faster by HA through the regulation of inflammation levels and signaling the body to build more blood vessels in the damaged area. Great potential in various applications, including wound healing, has been shown by the development and use of nanofiber formulations in medicine. However, challenges and limitations associated with nanofibers in medicine exist, such as reproducibility, proper characterization, and biological evaluation. By providing a biomimetic environment that enhances re-epithelialization and facilitates the delivery of active substances, nanofibers promote wound healing. In accelerating wound healing, promising results have been shown by HA-contained nanofiber formulations in diabetic wounds. Key strategies employed by these formulations include revascularization, modulation of the inflammation microenvironment, delivery of active substances, photothermal nanofibers, and nanoparticle-loaded fabrics. Particularly crucial is revascularization as it restores blood flow to the wound area, promoting healing. Wound healing can also be enhanced by modulating the inflammation microenvironment through controlling inflammation levels. Future perspectives in this field involve addressing the current challenges and limitations of nanofiber technology and further optimizing HA-contained nanofiber formulations for improved efficacy in diabetic wound healing. This includes exploring new fabrication techniques, enhancing the biocompatibility and biodegradability of nanofibers, and developing multifunctional nanofibers for targeted drug delivery. Not only does writing a review in the field of nanofiber-based wound dressings, particularly those containing hyaluronic acid, allow us to consolidate our current knowledge and understanding but also broadens our horizons. An opportunity is provided to delve deeper into the intricacies of this innovative therapeutic strategy, explore its potential and limitations, and envision future directions. By doing so, a contribution can be made to the ongoing advancements in tissue engineering and regenerative medicine, ultimately improving the quality of life for patients with diabetic wounds.

Application of extracorporeal shockwave therapy to improve microcirculation in diabetic foot ulcers: A prospective study

Extracorporeal shockwave therapy (ESWT) can induce wound healing by increasing tissue microcirculation. However, studies on the effect of ESWT on enhancing tissue microcirculation in diabetic foot ulcer (DFU), particularly on when the microcirculation increases after ESWT application, are still lacking. Therefore, we aimed to examine the effectiveness of ESWT in promoting microcirculation in DFU patients in a time-dependent manner. We included 50 feet of 25 patients with type 2 diabetes mellitus and Wagner grade I to II DFU in this study. The affected feet were used as the ESWT group and the unaffected contralateral feet were used as the control group. ESWT was performed in 3 sessions per week for a total of 3 weeks. Transcutaneous partial oxygen pressure (TcPO2) was used to evaluate the tissue microcirculation. The TcPO2 level (>43 mm Hg) in the ESWT group was recovered by the 2nd week of treatment, and statistical significance (P < .05) was demonstrated at the same time. From the 2nd week of ESWT, a significant increase in TcPO2 was observed in Wagner grade I and II DFU. These findings imply that the ESWT may improve microcirculation in patients with Wagner grades I to II DFU. However, this impact requires at least 2 weeks or more than 6 sessions. For better comparison, further studies with larger clinical groups and extended period are needed.

Development and use of the PodEssential and Paeds-PodEssential triage tools to define "essential" podiatry services. A Delphi survey, scoping review, and face validity testing study

BACKGROUND

The coronavirus pandemic resulted in unique challenges for podiatrists in Australia. Podiatrists were tasked with having to make triage decisions about face-to-face care without clear guidelines. This research aimed to develop podiatry triage tools to understand individual risk for adults and children, and explore the face validity of both tools.

METHODS

An online three-round modified Delphi technique was used to elicit podiatrists' opinions on conditions, assessments and social factors that elevate risk. Additional elements of known foot and/or leg risk were informed by a synchronous scoping review. Australian podiatrists who held a clinical role treating patients or directly managing podiatrists treating patients within the past six months were recruited. Where 70% of participants reported the same or similar theme in Round 1, statements were accepted with consensus. Where 50-69% of participants reported a similar theme, these were returned to participants to rate agreement using a four-point Likert agreement scale. Statements identified in the scoping review were added at Round 2, if not already identified by participants. The final round presented participants with triage tools, and a series of mock patient scenarios.. Participants were asked to indicate if they would or would not provide face to face podiatry service based on these scenarios.

RESULTS

There were 40 participants who responded to Round 1 (Adult presentations), of these, 23 participants also provided paediatric presentation responses. Participants developed and agreed upon 20 statements about risk in podiatry service delivery for both adults and children across Rounds 1 and 2. The PodEssential and Paed-PodEssential were developed based on these statements indicating stand-alone condition risk (tier 1), elements that should elevate risk (in the absence of a stand-alone condition) (tier 2), and assessments results identifiying a limb at risk (tier 3) in adults and children respectively. Participants utilising these tools in Round 3 more frequently indicated face-to-face service when mock patient scenarios included a greater number elements, suggesting the tool can be useful in making triage decisions.

CONCLUSION

The PodEssential and Paeds-PodEssential tools direct conditions requiring urgent attention as well as providing considered elements to a person's health status to assist in making triage decisions.

Comprehensive imaging of microcirculatory changes in the foot during endovascular intervention - A technical feasibility study

Chronic limb-threatening ischemia (CLTI) has a major impact on patient's lives and is associated with a heavy health care burden with high morbidity and mortality. Treatment by endovascular intervention is mostly based on macrocirculatory information from angiography and does not consider the microcirculation. Despite successful endovascular intervention according to angiographic criteria, a proportion of patients fail to heal ischemic lesions. This might be due to impaired microvascular perfusion and variations in the supply to different angiosomes. Non-invasive optical techniques for microcirculatory perfusion and oxygen saturation imaging have the potential to provide the interventionist with additional information in real-time, supporting clinical decisions during the intervention. This study presents a novel multimodal imaging system, based on multi-exposure laser speckle contrast imaging and multi-spectral imaging, for continuous use during endovascular intervention. The results during intervention display spatiotemporal changes in the microcirculation compatible with expected physiological reactions during balloon dilation, with initially induced ischemia followed by a restored perfusion, and local administration of a vasodilator inducing hyperemia. We also present perioperative and postoperative follow-up measurements with a pulsatile microcirculation perfusion. Finally, cases of spatial heterogeneity in the observed oxygen saturation and perfusion are discussed. In conclusion, this technical feasibility study shows the potential of the methodology to characterize changes in microcirculation before, during, and after endovascular intervention.

Clinical feasibility of diffuse speckle contrast analysis for real-time tissue perfusion monitoring

BACKGROUND

Adequate tissue perfusion is an important prognostic and diagnostic factor during the management of lower limb peripheral arterial disease. Convenient and real-time tissue perfusion monitoring remains an elusive challenge.

METHODS

Tissue perfusion on the dorsal and plantar surfaces of both feet of 20 participants was measured during and after cuff-induced ischemia using a novel 4-channel, laser-based perfusion monitoring device based on diffuse speckle contrast analysis technology (Pedra sensors). Participants were free of significant peripheral arterial disease. Transcutaneous partial pressure of oxygen (TcPO2) measurements were recorded concurrently for comparison.

RESULTS

Pedra sensors detected perfusion changes significantly more quickly than TcPO2 sensors. One minute after induced ischemia, the mean percent changes from baseline values (before ischemia) were -22.7±32.0% and -3.1±8.8% (P<.001) for Pedra and TcPO2 sensors, respectively. One minute into induced ischemia, Pedra sensors had reached 50.5% of the 5-minute ischemia reading whereas TcPO2 sensors had reached only 18.6% of the 5-minute reading (P=.046). Pedra sensors reported hyperemia immediately after cuff release with a mean percent change from baseline of 143.8±122.3%/173.4±121.8% on the dorsal/plantar surfaces while TcPO2 measurements were still recording negative changes at that time (-26.7±19.4%/-18.6±24.4% dorsal/plantar). Pedra sensors exhibited markedly lower interobserver and intraobserver variability than TcPO2 sensors.

CONCLUSIONS

A device based on diffuse speckle contrast analysis reported tissue perfusion in real time. Cuff-induced ischemia and hyperemia following cuff release were rapidly and consistently detected on both the dorsal and plantar surfaces of the foot. Diffuse speckle contrast analysis may have value for real-time perfusion monitoring during angiography procedures.

Acute Skin Wounds Treated with Mesenchymal Stem Cells and Biopolymer Compositions Alone and in Combination: Evaluation of Agent Efficacy and Analysis of Healing Mechanisms

We studied the efficacy of using mesenchymal stem cells (MSC) and a polymeric compound (based on chitosan and cellulose with integrated cerium dioxide nanoparticles (PCCD)) in wound healing, and to compare the effects with various invasive and external drugs used for the same purpose. Two wounds were made on the backs of each of 112 Wistar rats, removing the skin. Eight groups were studied: Control_0—intact wounds; Control_ss—0.9% NaCl injections; MSC injections; Control_msc—intact wounds on the opposite side of the body from the MSC group; external application of the PCCD; external application of a combination of the drugs PCCD + MSC; DCh –ointment Dioxomethyltetrahydropyrimidine + Chloramphenicol; and DHCB—injections of a deproteinized hemoderivative of calf blood. After 14 days, we evaluated the state and size of the wounds, studied the level of microcirculation, performed a histological study, and identified and counted the different types of cells. The most effective remedy was combination PCCD + MSC. The treatments in the PCCD and MSC groups were more effective than in the DHCB and DCh groups. Invasive drugs and DCh slowed the regeneration process. DHCB did not affect the rate of healing for acute wounds without ischemia during the first week. The proven efficacy of developed polymeric compounds demonstrates the feasibility of further studies in clinical practice.

Mobile Health-Based Thermometer for Monitoring Wound Healing After Endovascular Therapy in Patients With Chronic Foot Ulcer: Prospective Cohort Study

BACKGROUND

Foot temperature may increase after endovascular therapy, but the relationship between foot temperature and wound healing is unclear.

OBJECTIVE

This study was performed to evaluate the feasibility of a mobile health (mHealth)-based thermometer for foot temperature monitoring in patients with chronic foot ulcer before and after endovascular therapy and to determine the association between temperature change and wound healing time.

METHODS

This was a prospective cohort study. Patients who had a chronic foot ulcer (>3 months) and underwent endovascular therapy between June 2019 and December 2019 were included. The participants received standard medical care and endovascular therapy for revascularization. The mHealth-based thermometer, composed of 4 temperature-sensing chips, was put on the foot before and after endovascular therapy. Data from the chips were transferred to an associated mobile phone app via Bluetooth. Wound healing time was estimated using the Kaplan-Meier method, and the associations between baseline characteristics and clinical outcomes were evaluated using a Cox proportional hazard model.

RESULTS

A total of 163 patients with chronic foot ulcer who underwent endovascular therapy were enrolled and followed up until wound healing was complete or for 180 days. The mean foot temperature before endovascular therapy was 30.6 (SD 2.8 °C). Foot temperature increased significantly (mean 32.1 °C, SD 2.8 °C; P=.01) after the procedure. Wound healing time was significantly different in the Kaplan-Meier curves of the patient group with temperature changes ≥2 °C and the group with temperature changes ≤2 °C (log-rank P<.001). A foot temperature increase ≥2 °C after endovascular therapy was associated with increased wound healing in univariate analysis (hazard ratio [HR] 1.78, 95% CI 1.24-2.76, P=.02), and the association remained significant in multivariate analysis (HR 1.69, 95% CI 1.21-2.67, P=.03).

CONCLUSIONS

The mHealth-based thermometer was feasible and useful for foot temperature monitoring, which may provide health care professionals with a new endpoint for endovascular therapy. Foot temperature increases ≥2 °C after endovascular therapy were associated with faster wound healing in patients with chronic foot ulcer. Further studies are needed, however, to confirm these findings.

Efficacy of A Novel Smart Polymeric Nanodrug in the Treatment of Experimental Wounds in Rats

High-quality and aesthetic wound healing, as well as effective medical support of this process, continue to be relevant. This study aims to evaluate the medical efficacy of a novel smart polymeric nanodrug (SPN) on the rate and mechanism of wound healing in experimental animals. The study was carried out in male Wistar rats (aged 8-9 months). In these animals, identical square wounds down to the fascia were made in non-sterile conditions on the back on both sides of the vertebra. SPN was used for the treatment of one wound, and the other wound was left without treatment (control group). Biocompatible citrate-stabilized cerium oxide nanoparticles integrated into a polysaccharide hydrogel matrix containing natural and synthetic polysaccharide polymers (pectin, alginate, chitosan, agar-agar, water-soluble cellulose derivatives) were used as the therapeutic agent. Changes in the wound sizes (area, volume) over time and wound temperature were assessed on Days 0, 1, 3, 5, 7, and 14. Histological examination of the wounds was performed on Days 3, 7, and 14. The study showed that the use of SPN accelerated wound healing in comparison with control wounds by inhibiting the inflammatory response, which was measured by a decreased number of white blood cells in SPN-treated wounds. It also accelerated the development of fibroblasts, with an early onset of new collagen synthesis, which eventually led to the formation of more tender postoperative scars. Thus, the study demonstrated that the use of SPN for the treatment of wounds was effective and promising.