Clinical reliability and utility of skin perfusion pressure measurement in ischemic limbs—Comparison with other noninvasive diagnostic methods

Distal Bypass Improves Skin Perfusion Pressure at the Whole Foot Regardless of Angiosomes in Patients with Chronic Limb-Threatening Ischemia

Objectives: Distal bypass surgery's effect on tissue blood pressure beyond a focal angiosome remains debated. This study assessed tissue blood pressure in both direct revascularized angiosome (DRA) and indirect revascularized angiosome (IRA) after bypass surgery, utilizing repeated skin perfusion pressure (SPP) measurements. Methods: Twenty-nine limbs in 27 chronic limb-threatening ischemia (CLTI) patients (22 males and five females, age: 70.2 ± 9.3 years) who received distal bypass surgery were enrolled. SPP measurements were conducted for the DRA and IRA at 10 time intervals, encompassing both preoperative and postoperative periods of every 3-5 days until 30 days. Results: In total, 486 SPP measurements were collected from 58 measurement sites, and the transition of the SPP at the DRA was 35.4-62.5-59.5-70.2-58.2-62.2-63.1-63.6-63.8-73.4 mmHg and IRA was 29.4-53.4-53.7-58.8-51.3-63.1-47.9-62.1-57.6-61.0 mmHg. No significant differences were observed between SPP at the DRA and IRA. Fifteen wounds on the DRA (63%) and five on the IRA (100%) healed. Conclusion: Distal bypass improves SPP in both direct and IRAs of CLTI patients. These data indicated distal bypass improves tissue blood flow at entire foot regardless of angiosomes.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Prediction of pedicled flap survival preoperatively by operating indocyanine green angiography at 1,450 nm wavelength: an animal model study

Background

Predicting flap viability benefits patients by reducing complications and guides flap design by reducing donor areas. Due to varying anatomy, obtaining individual vascular information preoperatively is fundamental for designing safe flaps. Although indocyanine green angiography (ICGA) is a conventional tool in intraoperative assessment and postoperative monitoring, it is rare in preoperative prediction.

Methods

ICGA was performed on 20 male BALB/c mice under five wavelengths (900/1,000/1,100, /1,250/1,450 nm) to assess vascular resolution after ICG perfusion. A "mirrored-L" flap model with three angiosomes was established on another 20 male BALB/c mice, randomly divided into two equal groups. In Group A, a midline between angiosomes II and III was used as a border. In Group B, the points of the minimized choke vessel caliber marked according to the ICG signal at 1,450 nm wavelength (ICG1450) were connected. Necrotic area calculations, pathohistological testing, and statistical analysis were performed.

Results

The vascular structure was clearly observed at 1,450 nm wavelength, while the 900 to 1,100 nm failed to depict vessel morphology. Necrosis was beyond the borderline in 60% of Group A. Conversely, 100% of Group B had necrosis distal to the borderline. The number of choke vessels between angiosomes II and III was positively correlated with the necrotic area (%). The pathohistological findings supported the gross observation and analysis.

Conclusion

ICG1450 can delineate the vessel structure in vivo and predict the viability of pedicled skin flaps using the choke vessel as the border between angiosomes.

2020 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database and collects data of patients' background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or endovascular treatment. In 2020, 1299 CLI limbs (male 890 limbs: 69%) were registered by 85 facilities. Arteriosclerosis obliterans has accounted for 99% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2023; 32: 363-391.).

Predictive Factors for Limb Salvage and Foot Ulcer Recurrence in Patients with Chronic Limb-Threatening Ischemia After Multidisciplinary Team Treatment: A 6-Year Japanese Single-Center Study

Chronic limb-threatening ischemia (CLTI) is associated with a short-term risk of limb loss. Multidisciplinary teams are often involved in CLTI treatment; however, in Asian countries, multidisciplinary teams that include podiatrists specializing in foot wounds and vascular surgeons who can perform distal bypass surgery are lacking. We investigated predictive factors for limb salvage and foot ulcer recurrence in patients with CLTI treated by a Japanese single-center intensive multidisciplinary team over 6 years. We retrospectively investigated 84 patients with CLTI and foot ulcers who had undergone revascularization and wound treatment between October 2013 and December 2019. Following postrevascularization treatment, including undertaking minor amputations, the healing rate was 77.8%, and the average wound healing time was 75 ± 68 days. To achieve adequate blood supply, 17.7% of patients were treated using a combination of endovascular revascularization and bypass surgeries. Thirty-three (44%) patients had wound recurrence and there was wound recurrence within 6 months in 58.9% of these patients. Multivariate logistic regression analysis showed that postrevascularization skin perfusion pressure was significantly associated with wound healing (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.033-1.243, P = .0078). Diabetes mellitus (OR 9.72, 95% CI 1.855-50.937, P = .0071), and heart disease (OR 3.51, 95% CI 1.052-11.693, P = .0411) were significantly associated with wound recurrence (P < .05). Treatment within a single-center intensive multidisciplinary team resulted in good patient outcomes. Our study indicates that the revascularization endpoint of CLTI treatment should be marked by attainment of adequate blood supply and wound healing. The timing of revascularization and debridement is of utmost importance for the successful treatment of CLTI wounds.

Does the advantage of transcutaneous oximetry measurements in diabetic foot ulcer apply equally to free flap reconstruction?

BACKGROUND

Transcutaneous oxygen pressure (TcpO₂) is a precise method for determining oxygen perfusion in wounded tissues. The device uses either electrochemical or optical sensors.

AIM

To evaluate the usefulness of TcpO₂ measurements on free flaps (FFs) in diabetic foot ulcers (DFUs).

METHODS

TcpO₂ was measured in 17 patients with DFUs who underwent anterolateral thigh (ALT)-FF surgery and compared with 30 patients with DFU without FF surgery.

RESULTS

Significant differences were observed in the ankle-brachial index; duration of diabetes; and haemoglobin, creatinine, and C-reactive protein levels between the two groups. TcpO₂ values were similar between two groups except on postoperative days 30 and 60 when the values in the ALT-FF group remained < 30 mmHg and did not increase > 50 mmHg.

CONCLUSION

Even if the flap is clinically stable, sympathectomy due to adventitia stripping during anastomosis and arteriovenous shunt progression due to diabetic polyneuropathy could lead to low TcpO₂ values in the ALT-FF owing to its thick fat tissues, which is supported by the slow recovery of the sympathetic tone following FF. Therefore, TcpO₂ measurements in patients with DFU who underwent FF reconstruction may be less accurate than in those who did not.

Clinical impact of a novel lipoprotein apheresis treatment on no-option chronic limb-threatening ischemia: Result from the REDUCTION VISCOSITY study

INTRODUCTION

Lipoprotein apheresis (LA) is a possible adjunct treatment for no-option chronic limb-threatening ischemia (CLTI). This study aimed to assess the impact of a novel LA for no-option CLTI.

METHODS

We retrospectively assessed 19 patients with no-option CLTI treated using the novel LA. The primary outcome was a change in the skin perfusion pressure (SPP) after treatment with LA, and the secondary outcomes were changes in the viscosity-related laboratory parameters.

RESULTS

The wound-healing rate was 68.4%. The SPP at 2-3 weeks after series of LA were significantly higher both in the dorsal (41 vs. 53 mmHg, p = 0.037) and plantar (50.0 vs. 61.0 mmHg, p = 0.018) sides, compared to those at baseline. The viscosity-related laboratory markers were also significantly improved after the treatment; low-density lipoprotein-cholesterol (57.0 vs. 43.0 mg/dL, p = 0.002), fibrinogen (333 vs. 258 mg/dL, p < 0.001), and C-reactive protein (0.99 vs. 0.42 mg/dL, p = 0.001).

CONCLUSION

The novel LA significantly increased the SPP and improved relevant laboratory findings.

Assessing the Effects of Pulsed Electromagnetic Therapy on Painful Diabetic Distal Symmetric Peripheral Neuropathy: A Double-Blind Randomized Controlled Trial

BACKGROUND

Significant complications of diabetes include pain and the loss of sensation in peripheral limbs. Pain management of diabetic symmetric peripheral neuropathy (DSPN) remains challenging. This study reports on utilizing pulsed electromagnetic field therapy (PEMF) to reduce pain and improve skin perfusion pressure (SPP) in subjects with DSPN.

METHODS

A randomized, sham-controlled, double-blind, clinical trial was conducted on subjects afflicted with foot pain associated with DSPN. Following informed consent, 182 subjects with diabetes and confirmed DSPN were entered into the trial for a period of 18 weeks. Subjects were randomized into active PEMF treatment or nonactive sham and instructed to treat to their feet for 30 minutes, twice daily and report daily pain scores. Some patients in the active arm experienced a transient low field strength notification (LFSN) due to improper pad placement during treatment. Skin perfusion pressure measurements were also collected at two and seven weeks to assess peripheral arterial disease effects via measurement of local microcirculatory flow and blood pressure.

RESULTS

Patients in the active arm who did not receive an LFSN experienced a clinically significant 30% reduction in pain from baseline compared to sham (P < .05). Though not statistically significant, SPP in the active group trended toward improvement compared to sham.

CONCLUSIONS

Pulsed electromagnetic field therapy appears effective as a nonpharmacological means for reduction of pain associated with diabetic peripheral neuropathy and holds promise for improvement of vascular physiology in microcirculatory dysfunction associated with diabetic peripheral arterial disease.

2019 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The objective of this project is to elucidate the current status of the medical practice for CLI patients to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database (NCD) and collects data of patients’ background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated with surgery and/or endovascular treatment (EVT). In 2019, 1070 CLI limbs (male: 725 limbs, 68%) were registered by 83 facilities. Arteriosclerosis obliterans (ASO) accounted for 98% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. Although the registration format for the simultaneous surgery of bilateral limbs in NCD was changed to one patient and two limbs, JCLIMB still counted two patients and two limbs to eliminate discrepancy with the past annual reports. (This is a translation of Jpn J Vasc Surg 2022; 31: 157–185.)

Clinical utility of skin perfusion pressure measurement in diabetic foot wounds: An observational study

The degree of blood vessel stenosis significantly influences diabetic foot treatment. This study aimed to investigate the association between computed tomography angiography (CTA) stenosis and skin perfusion pressure (SPP), which are noninvasive vascular assessments used to evaluate diabetic foot wounds. Forty patients who reported diabetic foot wounds between November 2016 and December 2017 were included in the study. SPPand CTA were performed to evaluate the blood flow, and the rate of decrease in wound size was measured for the wounds corresponding to Meggitt-Wagner grade 1 at the first evaluation and 4-week intervals. The P value of the association between the degree of CTA stenosis and the SPP value was 0.915, and the P value of the association between CTA stenosis and decreasing rate of wound size was .235. There was no statistically significant association between SPP and the decreasing rate of wound size according to the degree of CTA stenosis. The association between SPP value and the decreasing rate of wound size was statistically significant (P < .05). The decreasing rate in diabetic foot wound size was significantly associated with SPP but not with CTA stenosis.

Efficacy of Early Closed Toe Amputation for Toe Ulcers with Suspected Osteomyelitis after Revascularization for Chronic Limb-Threatening Ischemia

Objective: In this study, we aim to evaluate the efficacy of early closed toe amputation on the wound management of toe ulcers with suspected osteomyelitis after revascularization for chronic limb-threatening ischemia (CLTI).

Methods: This retrospective study included patients who have underwent revascularization for toe ulcers associated with CLTI at Shizuoka Red Cross Hospital from 2015 to 2021. Wound management comprised early closed toe amputation for toe ulcers with suspected osteomyelitis (19 toes in 17 patients) or conservative treatment (35 toes in 26 patients). The primary endpoint was wound healing after revascularization. We compared the wound healing rate at 90 days and median healing time of early closed toe amputation versus conservative treatment.

Results: Compared with the conservative treatment, early closed toe amputation was able to achieve a better wound healing rate at 90 days (89.5% vs. 68.6%; P<0.01) and a shorter median healing time (19 days vs. 62 days; P=0.01).

Conclusion: There remains no established wound management for toe lesions associated with CLTI. Despite its several disadvantages including wound infection and possible foot deformity, early closed toe amputation for toe ulcers with suspected osteomyelitis can be considered a safe approach in terms of wound management.

Preoperative Transcutaneous Oxygen Perfusion Measurements in Predicting Atraumatic Wound Healing After Major Lower Extremity Amputation

This study examined the correlation between preoperative transcutaneous oxygen perfusion (TcPO₂) measurement and the success of wound healing after major lower extremity amputation. There is no validated consensus on how to accurately determine appropriate amputation levels. A TcPO₂ greater than 30 to 40 mm Hg is widely cited as a positive predictor of postoperative wound healing, but its validity has not been well defined. A retrospective chart review was performed for patients who underwent above-knee amputation (AKA), through-knee amputation, or below-knee amputation (BKA) at a single institution from 2012 to 2018 with preoperative TcPO₂ values and a minimum 30-day postoperative clinical follow-up. This review yielded 141 total amputations: 93 BKAs, 6 through-knee amputations, and 42 AKAs. Fifty-five amputations were unsuccessful, defined by postoperative wound dehiscence or infection. Of these, 37 were BKAs, 4 were through-knee amputations, and 14 were AKAs. There was a significant difference in preoperative TcPO₂ between the successful and unsuccessful amputations, at 46.2 and 38.3 mm Hg, respectively (P=.02). A TcPO₂ of 30 to 40 mm Hg showed a 68.8% success rate, and a TcPO₂ of less than 20 mm Hg showed an 18.2% success rate. A receiver operating characteristic curve for TcPO₂ predicting amputation success had an area under the curve of 0.53 for AKAs and 0.61 for BKAs; the diagnostic ability is far from prognostic. There is no linear association between TcPO₂ and success rate. A TcPO₂ of less than 20 mm Hg has a high positive predictive value for failure, but higher levels are not 100% predictive of wound healing success after amputation, as previously reported. [Orthopedics. 2022;45(3):174-180.].

Renin-Angiotensin-Aldosterone System (RAS) Inhibitors May Suppress the Prevalence of Peripheral Arterial Disease (PAD) in Elderly, Chronic Hemodialysis Patients

According to the hypertension guidelines, calcium antagonists are recommended as antihypertensive drugs for Stage 5 of chronic kidney disease (CKDG5) and late elderly patients, whereas renin-angiotensin-aldosterone system (RAS) inhibitors (RASi) are not recommended. We screened elderly CKDG5D patients at a single outpatient maintenance hemodialysis center for the progression of peripheral arterial disease (PAD) using the ankle-brachial index (ABI) and skin perfusion pressure (SPP) tests, as well as logistic regression analysis, to determine the association between PAD and the treatment with RASi and the association between the treatment with RASi and the need for hospitalization within one year of observation. With the presence of PAD as the explanatory variable and the presence of RASi as the objective variable, the odds ratio was 1.23 (95% confidence interval [CI] 0.37 to 3.82) in univariate analysis. After adjusting for confounding factors (age, gender, and hypertension), the odds ratio in multivariate analysis was 0.83 (95% CI 0.46 to 6.08). The presence or absence of PAD was significantly associated with an odds ratio of 3.24 (p = .04, 95% CI 1.0 to 10.25) and 4.63 (p = .026, 95% CI 1.20 to 17.84) in univariate and multivariate analyses, respectively, when the outcome was hospitalization at one year, regardless of the presence or absence of RASi. However, in univariate analysis, the odds ratio was 1.23 (95% CI 0.37 to 3.82) with RASi status as the explanatory variable and one-year hospitalization as the objective variable. After adjusting for confounders, the odds ratio in multivariate analysis was 0.83 (95% CI 0.46 to 6.08). Although further large-scale, multicenter studies are needed to establish the evidence, our results suggest that RASi treatment may have a suppressive effect on the prevalence of PAD and the need for hospitalization in elderly CKDG5 dialysis (CKDG5D) patients.

Phase I/IIa Feasibility Trial of Autologous Quality- and Quantity-Cultured Peripheral Blood Mononuclear Cell Therapy for Non-Healing Extremity Ulcers

Non-healing wounds are among the main causes of morbidity and mortality. We recently described a novel, serum-free ex vivo expansion system, the quantity and quality culture system (QQc), which uses peripheral blood mononuclear cells (PBMNCs) for effective and noninvasive regeneration of tissue and vasculature in murine and porcine models. In this prospective clinical study, we investigated the safety and efficacy of QQ-cultured peripheral blood mononuclear cell (MNC-QQ) therapy for chronic non-healing ischemic extremity wounds. Peripheral blood was collected from 9 patients with 10 chronic (>1 month) non-healing wounds (8 males, 1 female; 64-74 years) corresponding to ischemic extremity ulcers. PBMNCs were isolated and cultured using QQc. Within a 20-cm area surrounding the ulcer, 2 × 107 cells were injected under local anesthesia. Wound healing was monitored photometrically every 2 weeks. The primary endpoint was safety, whereas the secondary endpoint was efficacy at 12-week post-injection. All patients remained ambulant, and no deaths, other serious adverse events, or major amputations were observed for 12 weeks after cell transplantation. Six of the 10 cases showed complete wound closure with an average wound closure rate of 73.2% ± 40.1% at 12 weeks. MNC-QQ therapy increased vascular perfusion, skin perfusion pressure, and decreased pain intensity in all patients. These results indicate the feasibility and safety of MNC-QQ therapy in patients with chronic non-healing ischemic extremity wounds. As the therapy involves transplanting highly vasculogenic cells obtained from a small blood sample, it may be an effective and highly vasculogenic strategy for limb salvage.

Zinc deficiency impairs ischemia-induced angiogenesis

Objective

Zinc is an important essential trace metal involved in many physiologic functions, and its deficiency can affect the development of multiple organs, including the vasculature. However, clarity is lacking regarding the effects of zinc deficiency in the regulation of angiogenesis. We investigated the effects of zinc deficiency on the revascularization process through animal experiments and examined the relationship between the circulating zinc levels and tissue blood perfusion in patients with chronic limb-threatening ischemia (CLTI).

Methods

Zinc-deficient mice and control wild-type mice had undergone surgery to create unilateral hindlimb ischemia. Next, we examined the relationship between the serum zinc levels and skin perfusion pressure (SPP) as an index of tissue blood perfusion in patients with CLTI. A total of 51 patients with CLTI who had been referred for de novo revascularization for CLTI due to arteriosclerosis obliterans at our hospital from May 2012 to March 2016 were enrolled.

Results

The zinc-deficient mice showed a significant reduction in blood flow recovery rates in the ischemic limb and capillary density in the ischemic adductor muscle fibers compared with the control wild-type mice. The zinc-deficient mice also showed increased reactive oxygen species production after hindlimb ischemia. Nicotinamide adenine dinucleotide phosphate oxidase inhibitors ameliorated the zinc deficient-induced impairment of revascularization. The serum zinc levels were positively associated with the SPP in the CLTI patients. Multivariate regression analysis also revealed that the serum zinc levels were significantly correlated with the SPP in patients with CLTI.

Conclusions

Zinc deficiency impaired the rate of ischemia-induced revascularization through enhanced oxidative stress rates, suggesting that nutritional management for zinc sufficiency could be useful in CLTI prevention and treatment.

In the present study, we investigated the effects of zinc deficiency on angiogenesis. We found that zinc deficiency impaired the rate of ischemia-induced revascularization through enhanced oxidative stress rates in animal model. In addition, the skin perfusion pressures were positively associated with the serum zinc levels in patients with chronic limb-threatening ischemia. Thus, the intake of zinc could be useful for the prevention and/or treatment of ischemic limb disease. Circulating zinc levels could be a useful marker for the assessment of atherosclerosis-based vascular disease such as limb ischemia. Possibly, nutritional improvement by zinc intake could lead to the prevention and treatment of ischemic vascular disease.

Effectiveness of Flexor Tenotomy With a Transpositional Skin Flap for the Treatment of Severe Claw Toe Deformity With Mild-to-Moderate Joint Contracture

Flexor tenotomy is the most effective for achieving healing and for the prevention of toe ulcer resulting from claw toe deformity. Although flexor tenotomy might be effective for a flexible claw toe, it might not provide benefits for severe claw toe deformity involving joint contracture. We devised a method involving the transfer of a flap to the skin defect caused by tenotomy, as severe claw toe deformity is associated with skin contracture. Although transpositional skin flap might increase the postoperative complication risks, it can be effectively used for severe claw toe deformity involving mild-to-moderate joint contracture.

Skin Perfusion Pressure Predicts Early Wound Healing After Endovascular Therapy in Chronic Limb Threatening Ischaemia

OBJECTIVE

Skin perfusion pressure (SPP) has been proposed as a method to predict wound healing in chronic limb threatening ischaemia (CLTI). However, studies regarding the impact of SPP before and after endovascular therapy (EVT) on wound healing are limited. This study sought to evaluate the predictive value of SPP for early wound healing in CLTI treated by EVT.

METHODS

Between January 2018 and June 2020, 236 limbs (172 patients) with CLTI that underwent SPP measurement before and after EVT were included. SPP was measured before and 24 - 48 hours after the procedure. Early wound healing was defined as the achievement of complete epithelisation of all wounds without major amputation within three months of EVT.

RESULTS

Early wound healing was achieved in 145 (61.4%) limbs after EVT. Baseline SPP (44.1 ± 21.0 mmHg vs. 33.5 ± 21.7 mmHg; p < .001) and post-procedural SPP (61.8 ± 18.5 mmHg vs. 37.4 ± 19.9 mmHg; p < .001) were significantly higher in the wound healing (+) group than in the wound non-healing (-) group. The area under the receiver operating characteristics curve for early wound healing was 0.82 for post-procedural SPP with a cutoff value of 50 mmHg (sensitivity 74.5%, specificity 78.0%). The early wound healing rate was significantly higher with a post-procedural SPP ≥ 50 mmHg compared with a SPP < 50 mmHg (84.4% vs. 35.0%; p < .001).

CONCLUSION

Post-procedural SPP with a cutoff value of 50 mmHg was capable of predicting early wound healing after EVT in CLTI.

2018 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN CLI Database (JCLIMB), is created on the National Clinical Database and collects data of patients’ background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in the JCLIMB, together with those treated by surgery and/or endovascular treatment. In 2018, 1,145 CLI limbs (male 758 limbs, 66%) were registered by 90 facilities. Arteriosclerosis obliterans has accounted for 97% of the pathogenesis of these limbs. In this manuscript, the background data, ischemic status, treatment, and the early prognosis (within 1 month) of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2020; 29: 365–393.)

Popliteal artery patency is an indicator of ambulation and healing after below-knee amputation in vasculopaths

BACKGROUND

The posterior flap is a conventional technique for closing a below-knee amputation (BKA) that uses the gastrocnemius and soleus muscle and relies on the popliteal and posterior compartment arteries. If the prior mentioned arterial blood supply is compromised, this flap likely relies on collateral flow. The purpose of this study is to identify and differentiate any significant associations between preoperative popliteal and tibial arterial flow and BKA outcomes and patient-reported function.

METHODS

A retrospective review identified patients from a single tertiary wound care center who received BKAs and angiogram between 2010 and 2017 by a single surgeon. BKA complications, wound healing, and amputee ambulatory status at latest follow-up were all stratified for differences according to baseline tibial vessel run-off (VRO) status, popliteal artery patency, and popliteal angioplasty outcome. Chi-square, Fisher's exact, and Wilcoxon rank sum tests were used with significance defined as p ≤ 0.05.

RESULTS

BKAs were performed on 313 patients, of which, 167 underwent preoperative angiography. Thirty-two were excluded due to lack of adequate follow-up leaving a total of 135 patients in the studied population. Diabetes was present in 87%, and 36% had end-stage renal disease. By the study's conclusion, 92% of BKAs had fully healed, with median time-to-healing of 79 days (range 19-1314 days). 60% of patients were ambulatory at 9.5 months. Higher VRO was associated with higher healing rates and lower complications and time-to-healing. The conversion rate of BKA to above-knee amputation (AKA) was 4%. Preoperative popliteal patency was associated with higher postoperative ambulation rates when compared to patients without popliteal flow preoperatively (patent: 71/109, 65%; occluded: 10/26, 40%; p = 0.02) and independently increased the likelihood of postoperative ambulation.

CONCLUSIONS

The posterior flap design for BKA works even in the setting of popliteal occlusion. Complication rates are higher in patients with more compromised blood flow, which may ultimately lead to AKA. Given poor ambulation rates in patients who undergo AKA, the results of this study should encourage surgeons to consider a more functional BKA, even in instances when the popliteal artery is occluded.

Medial-to-lateral plantar loop technique for retrograde transcollateral recanalization of the lateral plantar artery in patients with type 3 plantar arch

A 89-year-old male presented with severe untreatable pain and ischemic non-healing ulcer in the left forefoot. The pre-procedural angiograms showed multiple stenosis of the superficial femoral and popliteal arteries, occlusion of anterior tibial artery, tibio-peroneal trunk (TTP) and distal posterior tibial artery (PTA), stenosis of the peroneal artery, and the patency of the medial plantar artery (MPA) as a single pedal artery, with very poor perfusion of the lateral aspect of the forefoot. The TTP and PTA were recanalized, and balloon angioplasty of superficial femoral artery and popliteal artery and peroneal artery was carried out. After unsuccessful antegrade attempts, the lateral plantar artery (LPA) was retrogradely recanalized performing the medial-to-lateral plantar loop, navigating from the deep branch of MPA to the plantar arch and reentering back in the common plantar artery through the LPA. Balloon angioplasty of LPA was performed though the retrograde and antegrade route. When the MPA is the single pedal artery, and the antegrade recanalization of the dorsalis pedis artery (DPA) and the LPA is not possible, the medial-to-lateral plantar loop is a feasible technique to recanalize the LPA retrogradely through the plantar arch.

The Degree of Blood Supply and Infection Control Needed to Treat Diabetic Chronic Limb-Threatening Ischemia with Forefoot Osteomyelitis

BACKGROUND

Diabetic foot ulcers combined with ischemia and infection can be difficult to treat. Few studies have quantified the level of blood supply and infection control required to treat such complex diabetic foot ulcers. We aimed to propose an index for ischemia and infection control in diabetic chronic limb-threatening ischemia (CLTI) with forefoot osteomyelitis.

METHODS

We retrospectively evaluated 30 patients with diabetic CLTI combined with forefoot osteomyelitis who were treated surgically from January 2009 to December 2016. After 44 surgeries, we compared patient background (age, sex, hemodialysis), infection status (preoperative and 1- and 2-week postoperative C-reactive protein [CRP] levels), surgical bone margin (with or without osteomyelitis), vascular supply (skin perfusion pressure), ulcer size (wound grade 0-3 using the Society for Vascular Surgery Wound, Ischemia, and foot Infection classification), and time to wound healing between patients with healing ulcers and those with nonhealing ulcers.

RESULTS

Preoperative CRP levels and the ratio of ulcers classified as wound grade 3 were significantly lower and skin perfusion pressure was significantly higher in the healing group than in the nonhealing group (P < .05). No other significant differences were found between groups.

CONCLUSIONS

This study demonstrates that debridement should be performed first to control infection if the preoperative CRP level is greater than 40 mg/L. Skin perfusion pressure of 55 mm Hg is strongly associated with successful treatment. We believe that this research could improve the likelihood of salvaging limbs in patients with diabetes with CLTI.

Objective Improvements in Peripheral Arterial Disease from Dorsal Root Ganglion Stimulation: A Case Series

BACKGROUND

The sympathetic nervous system (SNS) is important in the regulation of perfusion. Dorsal root ganglion stimulation (DRG-S) modulates sympathetic tone and is approved to treat complex regional pain syndrome, a disorder related to SNS dysfunction. We herein present 3 cases of DRG-S therapy to improve blood flow and symptoms of ischemia in peripheral arterial disease (PAD).

METHODS

Patient 1 is a 44-year-old female with dry gangrene of the third and fourth digits of her right hand due to Raynaud's syndrome who was scheduled for amputation of the affected digits. DRG-S leads were placed at the right C6, 7, and 8 DRG. Pulse volume recordings (PVR) were measured at baseline and after DRG-S. Patient 2 is a 55-year-old female with a non-healing ulcer of her left foot secondary to PAD scheduled for a below the knee amputation who underwent a DRG-S trial with leads placed at the left L4 and L5 DRG followed by a spinal cord stimulation trial with leads placed at the T9-T10 spinal levels for comparison. Transcutaneous oximetry (TcPO2) was measured at baseline and after 3 days of each therapy. Patient 3 is a 69-year-old female with persistent left foot pain at rest secondary to PAD with DRG-S leads placed at the left L4 and S1 levels.

RESULTS

All 3 patients experienced a significant reduction in pain with DRG-S, along with improvements in blood flow of the involved extremities, avoiding or limiting amputation. PVR improved dramatically with DRG-S in patient 1. A greater improvement in TcPO2 was seen with the DRG-S trial compared to spinal cord stimulation trial in patient 2. Patient 3 experienced an increase in walking distance and demonstrated long term efficacy and limb salvage at 32 months postimplantation.

CONCLUSIONS

Modulation of SNS output from DRG-S through orthodromic and antidromic autonomic pathways is likely responsible for improving blood flow. DRG-S may be a treatment option for PAD.

Asia-Pacific Consensus Statement on the Management of Peripheral Artery Disease: A Report from the Asian Pacific Society of Atherosclerosis and Vascular Disease Asia-Pacific Peripheral Artery Disease Consensus Statement Project Committee

BACKGROUND

Peripheral artery disease (PAD) is the most underdiagnosed, underestimated and undertreated of the atherosclerotic vascular diseases despite its poor prognosis. There may be racial or contextual differences in the Asia-Pacific region as to epidemiology, availability of diagnostic and therapeutic modalities, and even patient treatment response. The Asian Pacific Society of Atherosclerosis and Vascular Diseases (APSAVD) thus coordinated the development of an Asia-Pacific Consensus Statement (APCS) on the Management of PAD.

OBJECTIVES

The APSAVD aimed to accomplish the following: 1) determine the applicability of the 2016 AHA/ACC guidelines on the Management of Patients with Lower Extremity Peripheral Artery Disease to the Asia-Pacific region; 2) review Asia-Pacific literature; and 3) increase the awareness of PAD.

METHODOLOGY

A Steering Committee was organized to oversee development of the APCS, appoint a Technical Working Group (TWG) and Consensus Panel (CP). The TWG appraised the relevance of the 2016 AHA/ACC PAD Guideline and proposed recommendations which were reviewed by the CP using a modified Delphi technique.

RESULTS

A total of 91 recommendations were generated covering history and physical examination, diagnosis, and treatment of PAD-3 new recommendations, 31 adaptations and 57 adopted statements. This Asia-Pacific Consensus Statement on the Management of PAD constitutes the first for the Asia-Pacific Region. It is intended for use by health practitioners involved in preventing, diagnosing and treating patients with PAD and ultimately the patients and their families themselves.

Hallucal thenar index: A new index to detect peripheral arterial disease using laser speckle flowgraphy

OBJECTIVES

Laser speckle flowgraphy is a technology using reflected scattered light for visualization of blood distribution, which can be used to measure relative velocity of blood flow easily without contact with the skin within a short time. It was hypothesized that laser speckle flowgraphy may be able to identify foot ischemia. This study was performed to determine whether laser speckle flowgraphy could distinguish between subjects with and without peripheral arterial disease.

MATERIALS AND METHODS

All subjects were classified based on clinical observations using the Rutherford classification: non-peripheral arterial disease, class 0; peripheral arterial disease group, class 2-5. Rutherford class 6 was one of the exclusion criteria. Laser speckle flowgraphy measured the beat strength of skin perfusion as an indicator of average dynamic cutaneous blood flow change synchronized with the heartbeat. The beat strength of skin perfusion indicates the strength of the heartbeat on the skin, and the heartbeat strength calculator in laser speckle flowgraphy uses the blood flow data to perform a Fourier transform to convert the temporal changes in blood flow to a power spectrum. A total of 33 subjects with peripheral arterial disease and 40 subjects without peripheral arterial disease at a single center were prospectively examined. Laser speckle flowgraphy was used to measure hallucal and thenar cutaneous blood flow, and the measurements were repeated three times. The hallucal and thenar index was defined as the ratio of beat strength of skin perfusion value on hallux/beat strength of skin perfusion value on ipsilateral thenar eminence. The Mann-Whitney U-test was used to compare the median values of hallucal and thenar index and ankle brachial index between the two groups. A receiver operating characteristic curve for hallucal and thenar index of beat strength of skin perfusion was plotted, and a cutoff point was set. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index was explored in all subjects, the hemodialysis group, and the non-hemodialysis (non-hemodialysis) group.

RESULTS

The median value of the hallucal and thenar index of beat strength of skin perfusion was significantly different between subjects with and without peripheral arterial disease (0.27 vs. 0.87, respectively; P < 0.001). The median value of ankle brachial index was significantly different between subjects with and without peripheral arterial disease (0.8 vs. 1.1, respectively; P < 0.001). Based on the receiver operating characteristic of hallucal and thenar index, the cutoff was 0.4416 and the sensitivity, specificity, positive predictive value, and negative predictive value were 68.7%, 95%, 91.7%, and 77.6%, respectively. The correlation coefficients of all subjects, the hemodialysis group, and the non-hemodialysis group were 0.486, 0.102, and 0.743, respectively.

CONCLUSIONS

Laser speckle flowgraphy is a noninvasive, rapid, and widely applicable method. Laser speckle flowgraphy using hallucal and thenar index would be helpful to determine the differences between subjects with and without peripheral arterial disease. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index indicated that this index was especially useful in the non-hemodialysis group.

Intravascular Ultrasound–Guided Interventions for Below-the-Knee Disease in Patients With Chronic Limb-Threatening Ischemia

Purpose: To assess the utility of intravascular ultrasound (IVUS) during below-the-knee (BTK) interventions for patients with chronic limb-threatening ischemia (CLTI). Materials and Methods: This retrospective single-center study included 216 symptomatic patients (mean age 74.2±9.5 years; 167 men) with CLTI and BTK steno-occlusive disease who underwent successful balloon angioplasty between January 2016 and August 2018. Data from 88 vessels (58 patients) treated with IVUS-guided procedures were compared with corresponding values from 242 vessels (158 patients) treated with angiography-guided procedures. The primary outcomes included procedure-related variables of balloon size, contrast dose, and complication rates, as well as changes in ankle-brachial index (ABI) and skin perfusion pressure (SPP). Secondary outcomes included IVUS determination of vessel size, wire route, and calcification severity, as well as technical success and clinically-driven target lesion revascularization (TLR), limb salvage, and wound healing rates in the Rutherford category 5/6 patients as evaluated by propensity score matching analysis. Results: The patient and lesion characteristics were similar in both groups. The mean balloon size for IVUS-guided procedures was significantly larger (2.45±0.4 mm) compared with that for angiography-guided procedures (2.23±0.4 mm; p<0.001). The technical success (p=0.56) and complication rates (p=0.16) were similar between the groups. The postprocedure dorsal and plantar SPP and change in dorsal SPP improved more in the IVUS-guided group (p<0.001, p=0.015, and p=0.02, respectively). The IVUS-guided group had a significantly better wound healing rate than the angiography-guided group (p=0.006), although the freedom from TLR and limb salvage rates were similar between the groups (p=0.16 and p>0.99, respectively). Conclusion: IVUS-guided interventions for BTK lesions were safe and effective in accurately assessing the lesions. The results suggest that IVUS guidance of endovascular procedures has the potential to influence better clinical outcomes than angiography-guided angioplasty.

2017 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database (NCD) and collects data of patients’ background, therapeutic measures, early results, and long-term prognosis as long as five years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or EVT. In 2017, 1137 CLI limbs (male 760 limbs: 67%, female 377 limbs) were registered by 84 facilities. ASO has accounted for 98% of the pathogenesis of these limbs. In this manuscript, the background data, ischemic status, treatment and the early prognosis (within 1 month) of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2019; 28: 415–443.)

Vascular Assessment of the Lower Extremity with a Chronic Wound

Peripheral arterial disease (PAD) affects many individuals worldwide and is associated with increased morbidity and mortality. Controversy exists on whether or not to screen asymptomatic patients. Further complicating this is that many patients with a chronic lower extremity wound are often asymptomatic. PAD and traditional noninvasive vascular studies may be inaccurate in providing a correct diagnosis. A review of current and novel vascular assessment modalities along with their benefits and limitations are presented here. A combination of these vascular assessments may help improve accuracy in diagnosis, providing timely care to those patients in need.

Assessment of foot perfusion: Overview of modalities, review of evidence, and identification of evidence gaps

Patients with critical limb ischemia have nonhealing wounds and/or ischemic rest pain and are at high risk for amputation and mortality. Accurate evaluation of foot perfusion should help avoid unnecessary amputation, guide revascularization strategies, and offer efficient surveillance for patency. Our aim is to review current modalities of assessing foot perfusion in the context of the practical clinical management of patients with critical limb ischemia.

Below-the-Ankle Arrival Time as a Novel Limb Tissue Perfusion Index: Two-dimensional Perfusion Angiography Evaluation

Purpose: To identify lower limb 2-dimensional (2D) perfusion angiographic parameters that are related to skin perfusion pressure (SPP), a predictor of wound healing in patients with chronic limb-threatening ischemia (CLTI) undergoing below-the-knee (BTK) endovascular treatment (EVT). Materials and Methods: Thirty-three consecutive patients (mean age 74.5 years; 18 men) with 47 isolated BTK lesions in 33 limbs (Rutherford category 3–5) underwent EVT. Dorsal and plantar SPPs were measured before EVT and the day after. The indexed blood flow below the ankle was measured using 2D perfusion angiography before and after EVT to determine changes in perfusion parameters [arrival time (AT), time to peak, wash-in rate, mean transit time, and width and area under the time-density curve] at rest vs during hyperemia induced with a 20-mg intra-arterial papaverine infusion. Correlations between the 2D perfusion parameters and SPPs were assessed using the Pearson coefficient. The cutoff points to predict mean SPPs >40 mm Hg were analyzed using a receiver operating characteristic curve; outcomes are reported as the area under the curve (AUC) with 95% confidence interval (CI). Results: After EVT at rest and during hyperemia, only AT was significantly changed, although hyperemia produced significant changes in all the pre-/post-EVT 2D perfusion parameters except the wash-in rate. Dorsal and plantar SPPs after EVT were significantly increased and correlated with hyperemic AT and the AT ratio (hyperemia/at rest values) below the ankle. Hyperemic ATs <6.3 seconds and AT ratios <0.78 were predictive factors for a mean SPP >40 mm Hg, with AUCs of 0.83 (95% CI 0.67 to 0.99) and 0.78 (95% CI 0.61 to 0.95), respectively. Conclusion: Hyperemic ATs <6.3 seconds or AT ratios <0.78 below the ankle may be essential to obtain sufficient SPPs for limb salvage in BTK lesions. Thus, the use of 2D perfusion angiography enabled the monitoring of lower limb tissue perfusion throughout EVT and may thereby optimize treatment of CLTI.

Fluorescence angiography compared to toe blood pressure in the evaluation of severe limb ischemia

Background: Severity of limb ischemia in peripheral arterial disease (PAD) patients is usually evaluated by clinical assessment and toe blood pressure (TBP) or transcutaneous oxygen pressures (TcPO 2). Indocyanin green angiography (IGA) is a promising tool generating a foot cartography of skin microvascular perfusion. However, there is no consensus about the fluorescence parameters that should be used to evaluate ischemia. The purpose of this cross-sectional evaluation and 3-month clinical follow-up was to determine the best fluorescence parameter for the evaluation of severe PAD, using TBP as reference. Patients and methods: IGA was realized in patients with clinical suspicion of CLI in addition to TBP and TcPO 2. Parameters from the time intensity fluorescence curve measured on the foot were compared with TBP (primary reference), and with TcPO2. Clinical outcomes (amputation, revascularization, death) were recorded at 3 months follow-up. Results: Thirty-four patients were included and IGA could be analysed in 29 of them. When all limbs were studied, no significant correlation was found between any of the measured fluorescence parameters (saturation time, ingress slope, amplitude, delay) and TBP pressure neither TCPO2. In the limbs with CLI, a significant correlation between the TBP and amplitude on the forefoot was found. According to the outcome, none of the fluorescence parameters showed a significant prognostic value in contrast to the significant results for TBP and TcPO2. Conclusions: In this study, quantitative analysis of IGA parameters did not show any prognostic value, nor was there any significant statistical association with well-established prognostic parameters such as TBP and TcPO 2 in patients with suspected CLI. A correlation was found between amplitude and TBP in patients with CLI. Topographical information such as perfusion heterogeneity was not evaluated and remains a valuable target to be investigated.

Laser Doppler blood flowmeter as a useful instrument for the early detection of lower extremity peripheral arterial disease in hemodialysis patients: an observational study

BACKGROUND

A simpler method for detecting atherosclerosis obliterans is required in the clinical setting. Laser Doppler flowmetry (LDF) is easy to perform and can accurately detect deterioration in skin perfusion. We performed LDF for hemodialysis patients to determine the correlations between blood flow in the lower limbs and peripheral arterial disease (PAD).

METHODS

This retrospective study included 128 hemodialysis patients. Patients were categorized into the non-PAD group (n = 106) and PAD group (n = 22), 14 early stage PAD patients were included in the PAD group. We conducted LDF for the plantar area and dorsal area of the foot and examined skin perfusion pressure (SPP) during dialysis.

RESULTS

SPP-Dorsal Area values were 82.1 ± 22.0 mmHg in the non-PAD, and 59.1 ± 20.3 mmHg in PAD group, respectively (p < 0.05). The LDF-Plantar blood flow (Qb) values were 32.7 ± 15.5 mL/min in non-PAD group and 21.5 ± 11.3 mL/min in PAD group (p < 0.001). A total of 21 non-PAD patients underwent LDF before and during dialysis. The LDF-Plantar-Qb values were 36.5 ± 17.6 mL/min before dialysis and 29.6 ± 17.7 mL/min after dialysis (p < 0.05). We adjusted SPP and LDF for PAD using logistic regression, SPP-Dorsal-Area and LDF-P were significantly correlated with PAD (p < 0.05). The receiver-operating characteristic curve analysis indicated cut-off values of 20.0 mL/min for LDF-Plantar-Qb during dialysis.

CONCLUSION

LDF is a simple technique for sensitive detection of early-stage PAD. This assessment will help physicians identify early-stage PAD, including Fontaine stage II in clinical practice, thereby allowing prompt treatment.

Peripheral arterial disease screening and diagnostic practice: A scoping review

Early reliable, valid screening, diagnosis, and treatment improve peripheral arterial disease outcomes, yet screening and diagnostic practices vary across settings and specialties. A scoping literature review described reliability and validity of peripheral ischaemia diagnosis or screening tools. Clinical studies in the PUBMED database January 1, 1970, to August 13, 2018, were reviewed summarising ranges of reliability and validity of peripheral ischaemia diagnostic and screening tools for patients with non-neuropathic lower leg ischaemia. Peripheral ischaemia screening and diagnostic practices varied in parameters measured such as timing, frequency, setting, ordering clinicians, degree of invasiveness, costs, definitions, and cut-off points informing clinical and referral decisions. Traditional ankle/brachial systolic blood pressure index <0.9 was a reliable, valid lower leg ischaemia screening test to trigger specialist referral for detailed diagnosis. For patients with advanced peripheral ischaemia or calcified arteries, toe-brachial index, claudication, or invasive angiographic imaging techniques that can have complications were reliable, valid screening, and diagnostic tools to inform management decisions. Ankle/brachial index testing is sufficiently reliable and valid for use during routine examinations to improve timing and consistency of peripheral ischaemia screening, triggering prompt specialist referral for more reliable, accurate Doppler, or other diagnosis to inform treatment decisions.

Aggregated Data of JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Reports from 2013 to 2016

Since 2013, the Japanese Society for Vascular Surgery started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database (NCD) and collects the data of patients' background, therapeutic measures, early results, and long-term prognosis as long as five years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or endovascular treatment. The basic and early prognostic data of CLI, registered during the four years from 2013 to 2016, have been reported as annual reports. In this paper, for the purpose of clarifying the picture of clinical practice of CLI in Japan, we have compiled these data over the past four years. (This is a translation of Jpn J Vasc Surg 2019; 28: 219-247.).

Perfusion Assessment in Critical Limb Ischemia: Principles for Understanding and the Development of Evidence and Evaluation of Devices: A Scientific Statement From the American Heart Association

There are >12 million patients with peripheral artery disease in the United States. The most severe form of peripheral artery disease is critical limb ischemia (CLI). The diagnosis and management of CLI is often challenging. Ethnic differences in comorbidities and presentation of CLI exist. Compared with white patients, black and Hispanic patients have higher prevalence rates of diabetes mellitus and chronic renal disease and are more likely to present with gangrene, whereas white patients are more likely to present with ulcers and rest pain. A thorough evaluation of limb perfusion is important in the diagnosis of CLI because it can not only enable timely diagnosis but also reduce unnecessary invasive procedures in patients with adequate blood flow or among those with other causes for ulcers, including venous, neuropathic, or pressure changes. This scientific statement discusses the current tests and technologies for noninvasive assessment of limb perfusion, including the ankle-brachial index, toe-brachial index, and other perfusion technologies. In addition, limitations of the current technologies along with opportunities for improvement, research, and reducing disparities in health care for patients with CLI are discussed.

Peripheral artery disease: the new frontiers of imaging techniques to evaluate the evolution of regenerative medicine

Introduction: Stem cells (ESC, iPSC, MSC) are known to have intrinsic regenerative properties. In the last decades numerous findings have favored the development of innovative therapeutic protocols based on the use of stem cells (Regenerative Medicine/Cell Therapy) for the treatment of numerous diseases including PAD, with promising results in preclinical studies. So far, several clinical studies have shown a general improvement of the patient's clinical outcome, however they possess many critical issues caused by the non-randomized design of the limited number of patients examined, the type cells to be used, their dosage, the short duration of treatment and also their delivery strategy. Areas covered: In this context, the use of the most advanced molecular imaging techniques will allow the visualization of very important physio-pathological processes otherwise invisible with conventional techniques, such as angiogenesis, also providing important structural and functional data. Expert opinion: The new frontier of cell therapy applied to PAD, potentially able to stop or even the process that causes the disease, with particular emphasis on the clinical aspects that different types of cells involve and on the use of more innovative molecular imaging techniques now available.

Utility of skin perfusion pressure values with the Society for Vascular Surgery Wound, Ischemia, and foot Infection classification system

OBJECTIVE

The addition of skin perfusion pressure (SPP) might enhance the predictive value of the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system. The purpose of the present study was to evaluate the SPP for each WIfI classification stage among patients with foot wounds by cross-referencing the results of prospectively monitored limb outcomes and to derive the SPP criteria that could be combined with other measurements to grade ischemia for the WIfI classification.

METHODS

From July 2015 to June 2017, patients with foot wounds that met the WIfI classification criteria were prospectively enrolled. We assessed the limbs using the WIfI ischemia grade without measuring the transcutaneous oxygen pressure but measured the SPP. After monitoring for 1 year, the predictability of the WIfI stages was analyzed according to whether the limbs had not healed (unchanged or worsened wounds, minor or major amputation, all-cause death) or had healed (improved or healed wounds) by comparing stages 1 and 2 with stages 3 and 4. We also statistically analyzed the SPP values that could be the boundary values between each ischemia grade and reevaluated the predictability of the WIfI stages with the boundary SPP values.

RESULTS

We enrolled a total of 91 limbs for 76 patients (mean age, 70.5 ± 12.0 years). The mean SPP values stratified by ischemia grade 0 to 3 were 52.1, 41.1, 27.1, and 18.8 mm Hg, respectively (an SPP of <30 mm Hg indicates severe ischemia). After monitoring for 1 year, 19 of 48 limbs in stage 1 and 2 and 35 of 43 in stage 3 and 4 were in the nonhealed group and 29 limbs in stage 1 and 2 and 8 limbs in stage 3 and 4 were in the healed group. The SPP boundary values between each ischemia (I) grade were calculated as 45 mm Hg for I-0/I-1, 35 for I-1/I-2, and 25 for I-2/I-3. When jointly using the boundary SPP values, the ischemia grade changed for 23 limbs, altering the distribution of the WIfI stages and limb outcomes: 11 of 38 limbs in stage 1 and 2 and 43 of 53 in stage 3 and 4 were transferred to the nonhealed group. The sensitivity, efficiency, and negative predictive value of WIfI staging improved when staging with SPP: from 65% to 80%, 70% to 77%, and 60% to 71%, respectively.

CONCLUSIONS

The SPP boundary values that could be used with ischemia grade in the WIfI classification were identified as 45, 35, and 25 mm Hg. The addition of SPP could improve the accuracy of the evaluation.

Association between the Cardio-Ankle Vascular Index and Diabetes Mellitus-Related Peripheral Arterial Disease in Chronic Hemodialysis Patients

BACKGROUND

Peripheral arterial disease (PAD) has increased in association with the increase in the numbers of patients with kidney disease or diabetes. The aim of this study was to assess the prevalence of PAD in hemodialysis patients with diabetes.

METHODS

To examine the usefulness of the cardio-ankle vascular index (CAVI) to screen for the presence of PAD, cross-sectional studies of 100 patients undergoing chronic hemodialysis were performed. The CAVI and other inflammatory markers were evaluated.

RESULTS

The CAVI was markedly elevated in patients with a history of PAD or cardiovascular disease. When dialysis patients were classified on the basis of CAVI quartiles, increased CAVI was associated with other risk factors for PAD.

CONCLUSION

The prevalence of PAD is high in elderly diabetic patients on hemodialysis. The present findings suggest that the CAVI can be a useful index that predicts the occurrence of macrovascular complications in dialysis patients with diabetes.

2016 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database (NCD) and collects data of patients' background, therapeutic measures, early results, and long term prognosis as long as five years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or EVT. In 2016, 1,092 CLI limbs (male 755 limbs: 70%) were registered by 91 facilities. ASO has accounted for 98% of the pathogenesis of these limbs. In this manuscript, the background data, the early prognosis, and 6-months' prognosis of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2019; 28: 1-27.).

Multidisciplinary Care for Critical Limb Ischemia: Current Gaps and Opportunities for Improvement

Critical limb ischemia (CLI), defined as ischemic rest pain or nonhealing ulceration due to arterial insufficiency, represents the most severe and limb-threatening manifestation of peripheral artery disease. A major challenge in the optimal treatment of CLI is that multiple specialties participate in the care of this complex patient population. As a result, the care of patients with CLI is often fragmented, and multidisciplinary societal guidelines have not focused specifically on the care of patients with CLI. Furthermore, multidisciplinary care has the potential to improve patient outcomes, as no single medical specialty addresses all the facets of care necessary to reduce cardiovascular and limb-related morbidity in this complex patient population. This review identifies current gaps in the multidisciplinary care of patients with CLI, with a goal toward increasing disease recognition and timely referral, defining important components of CLI treatment teams, establishing options for revascularization strategies, and identifying best practices for wound care post-revascularization.

Angiosome-Guided Intervention in Critical Limb Ischemia

The goals of treatment for critical limb ischemia (CLI) are alleviation of ischemic rest pain, healing of arterial insufficiency ulcers, and improving quality of life, thereby preventing limb loss and CLI-related mortality. Arterial revascularization is the foundation of a contemporary approach to promote amputation-free survival. Angiosome-directed revascularization has become a popular theory of reperfusion, whereby anatomically directed arterial flow is restored straight to the wound bed. Innovations in endovascular revascularization combined with a multidisciplinary strategy of wound care accelerate progress in CLI management. This article highlights advances in CLI management, including the clinical relevance of angiosome-directed revascularization, and provides considerations for future treatment of CLI.

Urgent need to clarify the definition of chronic critical limb ischemia - a position paper from the European Society for Vascular Medicine

Chronic critical lower limb ischemia (CLI) has been defined as ischemia that endangers the leg. An attempt was made to give a precise definition of CLI, based on clinical and hemodynamic data (Second European Consensus). CLI may be easily defined from a clinical point of view as rest pain of the distal foot or gangrene or ulceration. It is probably useful to add leg ulcers of other origin which do not heal because of severe ischemia, and to consider the impact of frailty on adverse outcome. From a hemodynamic viewpoint there is no consensus and most of the existing classifications are not based upon evidence. We should thus propose a definition and then validate it in a prospective cohort in order to define the patients at major risk of amputation, and also to define the categories of patients whose prognosis is improved by revascularisation. From today's available data, it seems clear that the patients with a systolic toe pressure (STP) below 30 mmHg must be revascularised whenever possible. However other patients with clinically suspected CLI and STP above 30 mmHg must be evaluated and treated in specialised vascular units and revascularisation has to be discussed on a case by case basis, taking into account other data such as the WiFi classification for ulcers.In conclusion, many useful but at times contradictory definitions of CLI have been suggested. Only a few have taken into account evidence, and none have been validated prospectively. This paper aims to address this and to give notice that a CLI registry within Europe will be set up to prospectively validate, or not, the previous and suggested definitions of CLI.

Laser speckle flowgraphy can also be used to show dynamic changes in the blood flow of the skin of the foot after surgical revascularization

Objectives

Laser speckle flowgraphy is a new method that enables the rapid evaluation of foot blood flow without contact with the skin. We used laser speckle flowgraphy to evaluate foot blood flow in peripheral arterial disease patients before and after surgical revascularization.

Materials and methods

A prospective single-center study. Thirty-one patients with 33 limbs that underwent surgical revascularization for peripheral arterial disease were included. Pre- and postoperative foot blood flows were measured on the plantar surface via laser speckle flowgraphy and skin perfusion pressure. The laser speckle flowgraphy device was used to visualize the blood flow distribution of the target skin and processed the pulse wave velocity of synchronized heart beats. The mean blood flow, which was expressed as the area of the pulse wave as the beat strength of skin perfusion on laser speckle flowgraphy converted into a numerical value, was assessed as dynamic changes following surgery. Beat strength of skin perfusion was also investigated in non-peripheral arterial disease controls (23 patients/46 limbs).

Results

The suitability of beat strength of skin perfusion in non-peripheral arterial disease controls was achieved; the beat strength of skin perfusion value was significantly higher in every area of interest in non-peripheral arterial disease controls compared to that in peripheral arterial disease limbs at the preoperative stage (105.8 ± 8.2 vs. 26.3 ± 8.2; P < 0.01). Although the pulse wave before surgery was visually flat in peripheral arterial disease patients, the pulse wave was remarkably and immediately improved through surgical revascularization. Beat strength of skin perfusion showed a dynamic change in foot blood flow (26.3 ± 8.2 at preoperation, 98.5 ± 6.7 immediately after surgery, 107.6 ± 5.7 at seven days after surgery, P < 0.01 for each compared to preoperation) that correlated with an improvement in skin perfusion pressure.

Conclusions

Laser speckle flowgraphy is a noninvasive, contact-free modality that is easy to implement, and beat strength of skin perfusion is a useful indicator of foot circulation during the perioperative period. Further analysis with a larger number of cases is necessary to establish appropriate clinical use.

Skin Perfusion Pressure and Wound Closure Time in Lower Extremity Wounds

Introduction

Peripheral Arterial Disease (PAD) affects approximately 8 million patients in the United States. We investigate the relationship of Skin Perfusion Pressure (SPP) and wound closure time in lower extremity wounds.

Methods

We conducted a retrospective study of 1125 lower extremity wounds in 998 patients between June 2006 and October 2014 in our wound clinic. We analyzed the relationship between SPPand wound closure time. SPP was measured using a Laser Doppler instrument.

Results

Patients with SPP values over 30 mmHg had shorter wound closure times, while patients with SPP values below 30 mmHg had a significantly longer wound closure time. Diabetic patients took longer to achieve wound closure compared to non-diabetics. No significant relationship was observed between SPP and wound closure time in relation to age or gender.

Conclusion

SPP is a useful tool in estimating time to wound closure and assessing the necessity of vascular interventions in lower extremity wounds.

2015 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), was created on the National Clinical Database and collects data of patients' background, therapeutic measures, early results, and long term prognosis as long as five years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or endovascular treatment. In 2015, 1138 CLI limbs (male, 796 limbs [70%]) were registered by 92 facilities. Arteriosclerosis obliterans has accounted for 98% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2018; 27: 155-185.).

Three-Year Outcomes of Surgical Versus Endovascular Revascularization for Critical Limb Ischemia: The SPINACH Study (Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischemia)

Supplemental Digital Content is available in the text.

Background—

The aim of this study was to compare clinical outcomes between surgical reconstruction and endovascular therapy (EVT) for critical limb ischemia (CLI) in today’s real-world settings.

Methods and Results—

This multicenter, prospective, observational study registered and followed 548 Japanese CLI patients. The registration was in advance of revascularization; 197 patients were scheduled to receive surgical reconstruction, and the remaining 351 were scheduled to receive EVT. The primary end point was 3-year amputation-free survival, compared between the 2 treatments in an intention-to-treat manner, using propensity score matching. Interaction analysis was additionally performed to explore which subgroups had better outcomes with surgical reconstruction or EVT. After propensity score matching, the 3-year amputation-free survival was not significantly different between the 2 groups (52% [95% confidence interval, 43%–60%] and 52% [95% confidence interval, 44–60%]; P=0.26). Subsequent interaction analysis identified (1) Wound, Ischemia, and foot Infection (WIfI) classification W-3, (2) fI-2/3, (3) history of ipsilateral minor amputation, (4) history of revascularization after CLI onset, and (5) bilateral CLI as the factors more favorable for surgical reconstruction, whereas (1) diabetes mellitus, (2) renal failure, (3) anemia, (4) history of nonadherence to cardiovascular risk management, and (5) contralateral major amputation were as those less favorable for surgical reconstruction.

Conclusions—

The 3-year amputation-free survival was not different between surgical reconstruction and EVT in the overall CLI population. The subsequent interaction analysis suggested that there would be a subgroup more suited for surgical reconstruction and another benefiting more from EVT.

Clinical Trial Registration—

URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000007050.