Clinical implications of the angiosome model in peripheral vascular disease

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.

Angiosome-Targeted Infrapopliteal Angioplasty: Impact on Clinical Outcomes-An Observational Study

Background: Revascularization based on the angiosome concept (AC) is a controversial subject because there is currently no clear evidence of its efficacy, due to the heterogeneity of patients (multiple and diverse risk factors and comorbidities, multiple variations in the affected angiosomes). Choke vessels change the paradigm of the AC, and the presence or absence of the plantar arch directly affects the course of targeted revascularization. The aim of this study was to evaluate the effect of revascularization based on the AC in diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: This retrospective analysis included 51 patients (40 men, 11 women), with a mean age of 69 years (66-72) and a total of 51 limbs, who presented with Rutherford 5-6 CLTI, before and after having undergone a drug-coated balloon angioplasty (8 patients) or plain balloon angioplasty (43). Between November 2018 and November 2019, all patients underwent below-the-knee balloon angioplasties and were followed up for an average of 12 months. The alteration of microcirculation was compared between directly and indirectly revascularized angiosomes. The study assessed clinical findings and patient outcomes, with follow-up investigations, comparing wound healing rates between the different revascularization methods. Patient records and periprocedural leg digital subtraction angiographies (DSA) were analyzed. Differences in outcomes after direct revascularization and indirect percutaneous transluminal angioplasty (PTa) were examined using Cox proportional hazards analysis, with the following endpoints: ulcer healing, limb salvage, and also amputation-free survival. Results: Direct blood flow to the angiosome supplying the ulcer area was achieved in 38 legs, in contrast to 13 legs with indirect revascularization. Among the cases, there were 39 lesions in the anterior tibial artery (ATA), 42 lesions in the posterior tibial artery (PTA), and 8 lesions in the peroneal artery (PA). According to a Cox proportional hazards analysis, having fewer than three (<3) affected angiosomes (HR 0.49, 95% CI 0.19-1.25, p = 0.136) was associated with improved wound healing. Conversely, wound healing outcomes were least favorable after indirect angioplasty (p = 0.206). When adjusting the Cox proportional hazard analysis for the number of affected angiosomes, it was found that direct drug-coated angioplasty resulted in the most favorable wound healing (p = 0.091). At the 1-year follow-up, the major amputation rate was 17.7%, and, according to a Cox proportional hazards analysis, atrial fibrillation (HR 0.85, 95% CI 0.42-1.69, p = 0.637), hemodialysis (HR 1.26, 95% CI 0.39-4.04, p = 0.699), and number of affected angiosomes > 3 (HR 0.94, 95% CI 0.63-1.39, p = 0.748) were significantly associated with poor leg salvage. Additionally, direct endovascular revascularization was associated with a lower rate of major amputation compared to indirect angioplasty (HR 1.09, 95% CI 0.34-3.50, p = 0.884). Conclusions: Observing the angiosomes concept in decision-making appears to result in improved rates of arterial ulcer healing and leg salvage, particularly in targeted drug-coated balloon angioplasty for diabetic critical limb ischemia, where multiple angiosomes are typically affected.

A Preliminary Look at the Macrovascular System for Transmetatarsal Amputation Success

OBJECTIVE

Transmetatarsal amputation (TMA) is a commonly used level of amputation that preserves most of the foot's function and independence. However, many TMAs fail, and patients go onto higher amputations. The primary endpoint of this study is to determine if source artery occlusions are correlated with TMA flap failure.

METHODS

A total of 82 patients with TMAs were retrospectively reviewed for healing rates between 2009 and 2019 at a single center. Forty-five of the patients had an angiogram, which was analyzed for source artery and overall TMA failure. Of the initial 82 patients, a cohort of 12 had documentation of specific flap failure and an angiogram performed. This cohort of 12 patients was used for correlation of flap failure with source artery occlusion.

RESULTS

Overall, the TMA healing rate was 45.28%. No correlation was noted between a specific source artery occlusion and overall TMA failure. However, a moderate positive correlation was seen with dorsalis pedis artery and peroneal artery occlusions and dorsal flap failure. No correlation was seen with the posterior tibial artery and plantar flap failure. A moderate negative correlation was seen with peroneal artery occlusion and plantar flap failure.

CONCLUSIONS

The authors concluded that retrograde flow through the angiosome principle is what allowed for successful outcomes in TMAs. Physicians are urged to carefully plan, dissect, and preserve these vessels to help prevent TMA flap failure, especially in patients with vascular risk or disease.

Longitudinal changes in skin perfusion pressure after endovascular therapy in patients with chronic limb-threatening ischemia

PURPOSE

The skin perfusion pressure (SPP) increases after endovascular treatment (EVT) for up to 1 month, although changes beyond 1 month remain unreported. This study aimed to investigate the changes in the SPP over time after EVT.

MATERIALS AND METHODS

This was a single-center, prospective, observational study. We included patients with chronic limb-threatening ischemia who underwent EVT between January 2019 and July 2022. We evaluated the SPP after EVT monthly for up to 3 months and compared the changes in the SPP between patients with different comorbidities. Moreover, we investigated the independent predictors of recurrent foot ischemia using a multivariate analysis.

RESULTS

Overall, 87 patients were included in the study. The mean preprocedural dorsal and plantar SPP was 33.9 ± 14.7 and 33.4 ± 13.1 mmHg, respectively. After the procedure, the SPP significantly increased at 1 month but decreased during months 2 and 3 (the dorsal SPP at 1, 2, and 3 months was 59.6 ± 20.3, 48.3 ± 20.9, and 39.7 ± 14.7, respectively, p < 0.01; the plantar SPP at 1, 2, and 3 months was 57.3 ± 18.2, 48.2 ± 15.6, and 40.5 ± 15.3, respectively, p < 0.01). Changes in the SPP did not differ among patients with different comorbidities. The multivariate analysis revealed that severe infrapopliteal calcification was an independent predictor of recurrent foot ischemia (odds ratio, 3.8; 95% confidence interval, 1.1-13.4; p = 0.04).

CONCLUSION

The SPP after EVT significantly increased at 1 month and decreased monthly for up to 3 months. Severe infrapopliteal calcification was the sole predictor of foot ischemia recurrence. Meticulous follow-up after EVT and regular hemodynamic examinations are important.

Chronic Limb-Threatening Ischemia in Patients with Type 2 Diabetes: Revascularization Index as a Predictor for Primary Endovascular Intervention Outcome

Purpose

Chronic limb-threatening ischemia in patients with diabetes is associated with a high risk of adverse outcomes. The associated co-morbidities, the heterogeneity of foot presentation and the distribution of atherosclerotic lesions led to the emergence of multiple revascularization strategies and scoring systems to improve management outcomes. This study aimed to introduce a new index, the revascularization index (RI), and to assess its predictive value for the outcomes of primary endovascular intervention in patients with type 2 diabetes presenting with chronic limb-threatening ischemia.

Patients and Methods

A retrospective electronic medical records review was conducted for patients with type 2 diabetes presenting with chronic limb-threatening ischemia managed at King Abdullah University Hospital by primary endovascular interventions between January 2014 and August 2019. The RI was analyzed for its predictive value for the treatment outcomes.

Results

A total of 187 patients were included in this study, with a major lower limb amputation rate of 19.3%. The performance of the RI was excellent in predicting secondary revascularization (AUC = 0.80, 95% CI: 0.73-0.86, p-value < 0.001), good to predict major amputation (AUC = 0.76, 95% CI: 0.67-0.85, p-value = 0.047), and poor in predicting death (AUC = 0.46, 95% CI: 0.40-0.55, p-value = 0.398). RI of <1.21 was significantly associated with a higher risk of major lower limb amputation (HR = 5.8, 95% CI: 1.25-26.97, p-value < 0.025), and RI of < 1.3 was associated with a higher risk for secondary revascularization.

Conclusion

The RI can be used to predict major adverse lower limb events (MALE). It might be used as a guide for the extent of endovascular interventions for diabetic chronic limb-threatening ischemia with multi-level outflow atherosclerotic disease.

Evaluation of the Angiosome Concept Using Near-Infrared Fluorescence Imaging with Indocyanine Green

BACKGROUND

The angiosome concept is defined as the anatomical territory of a source artery within all tissue layers. When applying this theory in vascular surgery, direct revascularization (DR) is preferred to achieve increased blood flow toward the targeted angiosome of the foot in patients with lower extremity arterial disease (LEAD). This study evaluates the applicability of the angiosome concept using quantified near-infrared (NIR) fluorescence imaging with indocyanine green (ICG).

METHODS

This study included patients undergoing an endovascular- or surgical revascularization of the leg between January 2019 and December 2021. Preinterventional and postinterventional ICG NIR fluorescence imaging was performed. Three angiosomes on the dorsum of the foot were determined: the posterior tibial artery (hallux), the anterior tibial artery (dorsum of the foot) and the combined angiosome (second to fifth digit). The angiosomes were classified from the electronic patient records and the degree of collateralization was classified based on preprocedural computed tomography angiography and/or X-ray angiography. Fluorescence intensity was quantified in all angiosomes. A subgroup analysis based on endovascular or surgical revascularized angiosomes, and within critical limb threatening ischemia (CLTI) patients was performed.

RESULTS

ICG NIR fluorescence measurements were obtained in 52 patients (54 limbs) including a total of 157 angiosomes (121 DR and 36 indirect revascularizations [IR]). A significant improvement of all perfusion parameters in both the directly and indirectly revascularized angiosomes was found (P-values between <0.001-0.007). Within the indirectly revascularized angiosomes, 90.6% of the scored collaterals were classified as significant. When comparing the percentual change in perfusion parameters between the directly and indirectly revascularized angiosomes, no significant difference was seen in all perfusion parameters (P-values between 0.253 and 0.881). Similar results were shown in the CLTI patients subgroup analysis, displaying a significant improvement of perfusion parameters in both the direct and indirect angiosome groups (P-values between <0.001 and 0.007), and no significant difference when comparing the percentual parameter improvement between both angiosome groups (P-values between 0.134 and 0.359). Furthermore, no significant differences were observed when comparing percentual changes of perfusion parameters in directly and indirectly revascularized angiosomes for both endovascular and surgical interventions (P-values between 0.053 and 0.899).

CONCLUSIONS

This study proves that both DR and IR of an angiosome leads to an improvement of perfusion. This suggests that interventional strategies should not only focus on creating in-line flow to the supplying angiosome. One can argue that the angiosome concept is not applicable in patients with LEAD.

Choosing the appropriate catheter and wire in peripheral intervention

Endovascular treatment is becoming more common in managing patients with peripheral arterial disease. A carefully planned procedure is crucial for the outcome of the procedure. Several steps are necessary when performing endovascular procedures, including preplanning with vascular imaging using computed tomography angiography (CTA) or magnetic resonance angiography (MRA), choosing the right access and technique, and using the right devices (guidewires, sheaths, catheters). The length, diameter, stiffness, coating, and tip shape of the guidewire should be adjusted according to the initial information and preparation. A sheath is not always necessary but can be beneficial when several catheter changes are planned. There are three types of angiographic catheter (flush, exchange, and selective), each of which should be considered and used wisely according to its function. The guidewire, sheath, and catheter choices will follow from the initial information gathered, the access and technique chosen, and the availability of the devices.

The impact of an angiosome-targeted revascularization on healing rate, limb salvage and survival in critical limb threatening ischemia

OBJECTIVE

According to the angiosome concept ulcer healing and limb salvage should be superior if direct arterial flow to the source vessel of an affected angiosome is established compared to indirect flow where the angiosome is perfused by means of collaterals. The objective of this study was to evaluate the impact of direct versus indirect revascularization (DR/IR) in endovascular versus bypass surgery on ulcer healing, limb salvage and mortality.

MATERIALS AND METHODS

A retrospective analysis of both endovascular and bypass distal (below the knee) lower limb revascularizations for chronic limb-threatening ischemia (CLTI) between 1993 and 2014 was performed.

RESULTS

The study population consisted of 126 endovascular and 198 bypass procedures. DR and IR were achieved in 57.4% and 42.6% limbs respectively. DR was not superior to IR regarding all three major endpoints when endovascular and bypass procedures were analyzed separately. Endovascular and bypass procedures resulted in comparable healing rates. All patients who did not achieve wound healing (HR 7.49; 95% CI 4.25-13.20, p = .0001) or needed to be treated with a bypass (HR 1.79; 95% CI 1.05-3.05, p = .034) were at an increased risk for major amputation. Increased mortality rate was noted after endovascular procedures (HR 1.45; 95% CI 1.04-2.00, p = .026).

CONCLUSION

This retrospective study with comparable results for DR and IR did not support the angiosome concept. Achieving wound healing remains critical in patients with CLTI to reduce major amputation rates. Overall the implications of the angiosome concept seem to be limited due to its feasibility in patients with CLTI.

Near-infrared fluorescence imaging with indocyanine green for quantification of changes in tissue perfusion following revascularization

OBJECTIVES

Current diagnostic modalities for patients with peripheral artery disease (PAD) mainly focus on the macrovascular level. For assessment of tissue perfusion, near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) seems promising. In this prospective cohort study, ICG NIR fluorescence imaging was performed pre- and post-revascularization to assess changes in foot perfusion.

METHODS

ICG NIR fluorescence imaging was performed in 36 patients with PAD pre- and post-intervention. After intravenous bolus injection of 0.1 mg/kg ICG, the camera registered the NIR fluorescence intensity over time on the dorsum of the feet for 15 min using the Quest Spectrum Platform®. Time-intensity curves were plotted for three regions of interest (ROI): (1) the dorsum of the foot, (2) the forefoot, and (3) the hallux. Time-intensity curves were normalized for maximum fluorescence intensity. Extracted parameters were the maximum slope, area under the curve (AUC) for the ingress, and the AUC for the egress. The non-treated contralateral leg was used as a control group.

RESULTS

Successful revascularization was performed in 32 patients. There was a significant increase for the maximum slope and AUC egress in all three ROIs. The most significant difference was seen for the maximum slope in ROI 3 (3.7%/s to 6.6%/s, p < 0.001). In the control group, no significant differences were seen for the maximum slope and AUC egress in all ROIs.

CONCLUSIONS

This study shows the potential of ICG NIR fluorescence imaging in assessing the effect of revascularization procedures on foot perfusion. Future studies should focus on the use of this technique in predicting favorable outcome of revascularization procedures.

Assessment of Tissue Viability Following Amputation Surgery Using Near-Infrared Fluorescence Imaging With Indocyanine Green

BACKGROUND

Patients with chronic limb threatening ischemia have a risk of undergoing a major amputation within 1 year of nearly 30% with a substantial risk of re-amputation since wound healing is often impaired. Quantitative assessment of regional tissue viability following amputation surgery can identify patients at risk for impaired wound healing. In quantification of regional tissue perfusion, near-infrared (NIR) fluorescence imaging using Indocyanine Green (ICG) seems promising.

METHODS

This pilot study included adult patients undergoing lower extremity amputation surgery due to peripheral artery disease or diabetes mellitus. ICG NIR fluorescence imaging was performed within 5 days following amputation surgery using the Quest Spectrum Platform^Ⓡ. Following intravenous administration of ICG, the NIR fluorescence intensity of the amputation wound was recorded for 10 minutes. The NIR fluorescence intensity videos were analyzed and if a fluorescence deficit was observed, this region was marked as "low fluorescence." All other regions were marked as "normal fluorescence."

RESULTS

Successful ICG NIR fluorescence imaging was performed in 10 patients undergoing a total of 15 amputations. No "low fluorescence" regions were observed in 11 out of 15 amputation wounds. In 10 out of these 11 amputations, no wound healing problems occurred during follow-up. Regions with "low fluorescence" were observed in 4 amputation wounds. Impaired wound healing corresponding to these regions was observed in all wounds and a re-amputation was necessary in 3 out of 4. When observing time-related parameters, regions with low fluorescence had a significantly longer time to maximum intensity (113 seconds vs. 32 seconds, P = 0.003) and a significantly lesser decline in outflow after five minutes (80.3% vs. 57.0%, P = 0.003).

CONCLUSIONS

ICG NIR fluorescence imaging was able to predict postoperative skin necrosis in all four cases. Quantitative assessment of regional perfusion remains challenging due toinfluencing factors on the NIR fluorescence intensity signal, including camera angle, camera distance and ICG dosage. This was also observed in this study, contributing to a large variety in fluorescence intensity parameters among patients. To provide surgeons with reliable NIR fluorescence cut-off values for prediction of wound healing, prospective studies on the intra-operative use of this technique are required. The potential prediction of wound healing using ICG NIR fluorescence imaging will have a huge impact on patient mortality, morbidity as well as the burden of amputation surgery on health care.

Bifurcated bypass in severe chronic limb threatening ischaemia

OBJECTIVES

Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia.

METHODS

Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed.

RESULTS

Mean follow-up period was 25.1 months (range 2-72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford's class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%.

CONCLUSIONS

Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.

Angiosomal Vascular Occlusions, Deep-Tissue Pressure Injuries, and Competing Theories: A Case Report

ABSTRACT

Compression of the soft tissue between a support surface and a bony prominence has long been the accepted primary mechanism of pressure injury (PrI) formation, with the belief that said compression leads to capillary occlusion, ischemia, and tissue necrosis. This explanation presupposes an "outside-in" pathophysiologic process of tissue damage originating at the local capillary level. Despite advances in prevention protocols, there remains a stubbornly consistent incidence of severe PrIs including deep-tissue injuries, the latter usually evolving into stage 4 PrIs with exposed bone or tendon. This article presents just such a perioperative case with the aim of providing further evidence that these more severe PrIs may result from ischemic insults of a named vessel within specific vascular territories (labeled as angiosomes). Pressure is indeed a factor in the formation of severe PrIs, but these authors postulate that the occlusion occurred at the level of a named artery proximal to the lesion. This vascular event was likely attributable to low mean arterial pressure. The authors suggest that the terminology proposed three decades ago to call both deep-tissue injuries and stage 4 PrIs "vascular occlusion pressure injuries" should be the topic of further research and expert consensus.

Repeat BTK revascularization: when, how and what are the results?

INTRODUCTION

Owing to the ageing of the population and rising rates of diabetes, more patients suffering from chronic limb threatening ischemia (CLTI) need revascularization for often complex, multilevel peripheral arterial occlusive disease. Below the knee (BTK) lesions are common in CLTI and short-term outcomes of BTK endovascular revascularizations have improved substantially over the last decade as a consequence of improved techniques and dedicated low profile devices.

EVIDENCE ACQUISITION

The manuscript summarized the information identified through a limited literature review conducted on key resources including MEDLINE and EMBASE databases as well as conference proceedings. The keywords were "angioplasty," "endovascular intervention," "infrapopliteal," "tibial arteries" and "below the knee." The search was limited to contemporary English-language documents published between 2000 and 2020.

EVIDENCE SYNTHESIS

Rates of re-stenosis and re-occlusion are high after infrapopliteal interventions limiting long-term success and necessitating frequent repeat procedures.

CONCLUSIONS

In this article we aimed to summarize current knowledge regarding the need, options and outcome of repeat BTK interventions through a limited literature review and presentation of own data.

Validation of Global Limb Anatomical Staging System (GLASS) in patients with hemodialysis and Chronic Limb-Threatening Ischemia after endovascular treatment

Recently, Society for Vascular Surgery guideline recommends evaluating anatomic pattern with use of Global Limb Anatomic Staging System (GLASS) in Chronic Limb-Threatening Ischemia (CLTI) patients. The aim of this study is to validate GLASS stage into CLTI patients on hemodialysis (HD) and investigate the impact of GLASS stage to wound healing and amputation-free survival (AFS). Between April 2009 and March 2018, we performed EVT for 154 limbs in CLTI patients on HD. GLASS was defined as femoropopliteal (FP) and infrapopliteal (IP) segments separately graded (0-4), then combined into three GLASS stages for the limb (I-III). We divided them into three GLASS stages with using this system. We compared the clinical outcomes between three groups (GLASS I, GLASS II, and GLASS III). Patient characteristics were almost similar between the three groups. Lesion characteristics was more complex and the rate of success was lower in GLASS III. Cox regression multivariate analysis revealed that diabetes mellitus (HR 2.4, 95% CI 1.37-4.01, p < 0.01) and WIfI high (HR 2.3, 95% CI 1.04-6.01, p = 0.04) were the predictors of non-wound healing, whereas age (HR 1.6, 95% CI 1.09-2.29, p = 0.01), WIfI clinical stage 4 (HR 2.4, 95% CI 1.30-4.36, p < 0.01), and non-ambulatory status (HR 2.0, 95% CI 1.17-3.29, p = 0.01) were the predictors of AFS. GLASS stage in CLTI patient on HD could not predict wound healing, and AFS in this study.

Infrapopliteal endovascular intervention and the angiosome concept: intraoperative real-time assessment of foot regions' blood volume guides and improves direct revascularization

OBJECTIVE

There is no consensus for determining which vessel should be revascularized in patients with multiple diseased infrapopliteal arteries. The angiosome concept may guide a more efficient targeted direct revascularization. Therefore, we conducted a study to assess whether the regional evaluation of foot blood volume may guide direct revascularization (DR) and if it will lead to better perfusion improvement than indirect revascularization (IR).

METHODS

We performed a prospective single-center observational cohort study in patients treated in the Department of Vascular Surgery of Peking Union Medical College Hospital from November 2016 to April 2019. Twenty-seven patients treated with endovascular intervention were included. The intraoperative parenchymal blood volume of different foot regions was obtained for each patient using C-arm CT before and after intervention.

RESULTS

The intervention procedure significantly increased the overall blood volume (48.95 versus 81.97 ml/1000 ml, p = 0.002). Patients with direct revascularization had a 197% blood volume increase while patients with indirect revascularization had a 39% increase (p = 0.028). The preoperative blood volume was higher in patients with mild symptoms than in patients with severe symptoms (58.20 versus 30.45 ml/1000 ml, p = 0.039). However, in regard to postoperative blood volume, no significant difference was discovered between these two groups (75.05 versus 95.01 ml/1000 ml, p = 0.275).

CONCLUSION

Based on quantitative measurements, we conclude that overall blood volume can rise significantly after the intervention. Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring blood supply through the collateral circulation. Preoperative blood volume is associated with preoperative symptoms.

KEY POINTS

• Flat panel detector CT can obtain intraoperative perfusion status and guide treatment in endovascular intervention. • Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring the blood supply through the collateral circulation. • Patients with severer clinical manifestations have lower blood volumes.

Foot Angiosomes: Instructions for Use

In the last 15 years an abundance of literature has demonstrated that angiosome-targeted revascularization, either endovascular or open, can lead to better clinical results in patients with chronic limb-threatening ischemia. According to this literature, the angiosome concept should guide our treatment strategy in every chronic limb-threatening ischemia patient. However, in our daily practice, its application is often difficult or impossible. Most foot wounds spread over multiple angiosomes and, moreover, the value of an angiosome-guided revascularization approach can vary according to vascular anatomy, collateral vessel network, type of revascularization, and wound. The aim of this article is to explore values and limits of the angiosome concept, and to propose some “instructions for use” regarding its application in our daily practice.

Single snapshot spatial frequency domain imaging for risk stratification of diabetes and diabetic foot

Diabetic foot is one of the major complications of diabetes. In this work, a real-time Single Snapshot Multiple-frequency Demodulation (SSMD) - Spatial Frequency Domain Imaging (SFDI) system was used to image the forefoot of healthy volunteers, diabetes, and diabetic foot patients. A layered skin model was used to obtain the 2D maps of optical and physiological parameters, including cutaneous hemoglobin concentration, oxygen saturation, scattering properties, melanin content, and epidermal thickness, from every single snapshot. We observed a strong correlation between the measured optical and physiological parameters and the degree of diabetes. The cutaneous hemoglobin concentration, oxygen saturation, and epidermal thickness decrease, whereas the melanin content increases with the progress of diabetes. The melanin content further increases, and the reduced scattering coefficient and scattering power are lower for diabetic foot patients than those of both healthy and diabetic subjects. High accuracies (AUC) of 97.2% (distinguishing the diabetic foot patients among all subjects), 95.2% (separating healthy subjects from the diabetes patients), and 87.8% (classifying mild vs severe diabetes), respectively, are achieved in binary classifications in sequence using the SSMD-SFDI system, demonstrating its applicability to risk stratification of diabetes and diabetic foot. The prognostic value of the SSMD-SFDI system in the prediction of the occurrence of the diabetic foot and other applications in monitoring tissue microcirculation and peripheral vascular disease are also addressed.

Angiosome～From the Standpoint of Bypass Surgery

Although several studies showed that angiosome-guided endovascular treatment improved wound healing and major amputation rates in patients with chronic limb-threatening ischemia (CLTI), effectiveness of the angiosome concept to the treatment of ischemic foot remains to be elucidated, especially in bypass surgery. Arterial anatomy of the foot and ankle shows that there are multiple supplementary circulation including arterial–arterial connections and choke nexus, which indicates angiosome concept may carry limited importance in bypass surgery for CLTI. On the other hand, patients with diabetes or renal dysfunction have partial occlusion of arterial–arterial connections and, therefore, quite a few patients with CLTI in Japan may present with limited but impaired supplementary circulation around the ankle. This article reviews the arterial anatomy and circulation of the foot and ankle and discusses availability and limitations of angiosome-guided bypass surgery.

A systematic review of the use of near-infrared fluorescence imaging in patients with peripheral artery disease

OBJECTIVE

In the diagnosis of peripheral artery disease (PAD), the ankle-brachial index plays an important role. However, results of the ankle-brachial index are unreliable in patients with severe media sclerosis. Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) can provide information about tissue perfusion and has already been studied in oncologic, reconstructive, and cardiac surgery. For patients with PAD, this technique might give insight into skin perfusion and thereby guide treatment. We performed a systematic review of the literature on the use of NIR fluorescence imaging in patients with PAD.

METHODS

PubMed, MEDLINE, Embase, and Cochrane were searched for articles and abstracts on the application of NIR fluorescence imaging using ICG as fluorescent dye in patients with PAD. Our search strategy combined the terms "fluorescence," "ICG," or synonyms and "peripheral artery disease" or synonyms. The extracted data included fluorescence parameters and test characteristics for diagnosis of PAD.

RESULTS

Twenty-three articles were found eligible for this review using 18 different parameters for evaluation of the fluorescence signal intensity. NIR fluorescence imaging was used for four main indications: diagnosis, quality control in revascularization, guidance in amputation surgery, and visualization of vascular structures. For the diagnosis of PAD, NIR fluorescence imaging yields a sensitivity ranging from 67% to 100% and a specificity varying between 72% and 100%. Significant increases in multiple fluorescence parameters were found in comparing patients before and after revascularization.

CONCLUSIONS

NIR fluorescence imaging can be used for several indications in patients with PAD. NIR fluorescence imaging seems promising in diagnosis of PAD and guidance of surgeons in treatment, especially in patients in whom current diagnostic methods are not applicable. Further standardization is needed to reliably use this modality in patients with PAD.

Kissing Balloon Technique for Infrapopliteal Angioplasty in Patients with Critical Limb Ischemia

BACKGROUND

This study aimed to analyze the technical aspects and follow-up findings regarding patients with critical limb ischemia who underwent the kissing balloon technique (KBT).

METHODS

Thirty patients (34 bifurcations) were enrolled in this retrospective analysis between September 2010 and February 2017. All patients were submitted to infrapopliteal intervention for critical limb ischemia. The KBT is the primary treatment in 3 situations: for cases with >70% stenosis of the main artery located less than 1 cm of the bifurcation, occlusion of one branch with greater than 50% stenosis of the contralateral branch, or greater than 50% bilateral stenosis. Stents were considered in cases of recoil greater than 30% or flow-limiting recoil and were used in 7 of the 34 bifurcations (20.5%).

RESULTS

Primary patency at 30 days, 1 year, and 2 years was 100%, 68.1%, and 68.1, respectively. Limb salvage rates at 30 days, 1 year, and 2 years were 100%, 86.6%, and 65.0%, respectively. Wound healing rates at 30 days, 6 months, 1 year, and 2 years were 7.1%, 34.4%, 44.5%, and 68.7%, respectively. The bifurcations of the V-shape and T-shape groups were compared in terms of wound healing, primary patency, and limb salvage. No differences were observed in wound healing (P = 0.268), primary patency (P = 0.394), and limb salvage (P = 0.755).

CONCLUSIONS

The KBT is a feasible bifurcation approach for infrapopliteal angioplasties to maintain the patency of both branches after ballooning. The comparison between the anterior tibial artery and tibioperoneal trunk bifurcation and the peroneal artery and posterior tibial artery bifurcation revealed no difference in wound healing, primary patency, and limb salvage.

Editor's Choice - Impact of Endovascular Pedal Artery Revascularisation on Wound Healing in Patients With Critical Limb Ischaemia

OBJECTIVE

The present study investigated the impact of endovascular pedal artery revascularisation (PAR) on the clinical outcomes of patients with critical limb ischaemia (CLI).

METHODS

This retrospective analysis of a single centre cohort included 239 patients who underwent endovascular revascularisation of infrapopliteal arteries for a chronic ischaemic wound. PAR was attempted in 141 patients during the procedure. After propensity score matching, there were 87 pairs of patients with and without PAR.

RESULTS

After the matching, the two groups showed balanced baseline clinical and lesion characteristics. PAR was achieved in 60.9% of the PAR group. Direct angiosome flow was more frequently obtained in the PAR group than in the non-PAR group (81.6% vs. 34.5%; p < .001). Subintimal angioplasty (47.1% vs. 29.9%; p = .019) and pedal-plantar loop technique (18.4% vs. 0%; p < .001) were more frequent in the PAR group. At the one year follow up, the PAR group showed greater freedom from major amputation (96.3% vs. 84.2%; p = .009). The wound healing rate, overall survival, major adverse limb event, and freedom from re-intervention did not differ significantly between the two groups. However, the patient subgroup with successful PAR showed a higher wound healing rate than the non-PAR group (76.0% vs. 67.0%; p = .031). In a multivariable Cox proportional hazards regression model, successful PAR (hazard ratio [HR] 1.564, 95% confidence interval [CI] 1.068-2.290; p = .022) was identified as an independent factor associated with improved wound healing, whereas gangrene (HR 0.659, 95% confidence interval [CI] 0.471-0.923; p = .015), C reactive protein >3 mg/dL (HR 0.591, 95% CI 0.386-0.904; p = .015), and pre-procedural absence of pedal arch (HR 0.628, 95% CI 0.431-0.916; p = .016) were associated with impaired wound healing.

CONCLUSION

Successful PAR significantly improved wound healing in patients with CLI. Thus, efforts should be made to revascularise the pedal arteries, especially when the pedal arch is completely absent.

Radiotracer Imaging Allows for Noninvasive Detection and Quantification of Abnormalities in Angiosome Foot Perfusion in Diabetic Patients With Critical Limb Ischemia and Nonhealing Wounds

Background:

Single photon emission computed tomography (SPECT)/computed tomography (CT) imaging allows for assessment of skeletal muscle microvascular perfusion but has not been quantitatively assessed in angiosomes, or 3-dimensional vascular territories, of the foot. This study assessed and compared resting angiosome foot perfusion between healthy subjects and diabetic patients with critical limb ischemia (CLI). Additionally, the relationship between SPECT/CT imaging and the ankle–brachial index—a standard tool for evaluating peripheral artery disease—was assessed.

Methods and Results:

Healthy subjects (n=9) and diabetic patients with CLI and nonhealing ulcers (n=42) underwent SPECT/CT perfusion imaging of the feet. CT images were segmented into angiosomes for quantification of relative radiotracer uptake, expressed as standardized uptake values. Standardized uptake values were assessed in ulcerated angiosomes of patients with CLI and compared with whole-foot standardized uptake values in healthy subjects. Serial SPECT/CT imaging was performed to assess uptake kinetics of technetium-99m-tetrofosmin. The relationship between angiosome perfusion and ankle–brachial index was assessed via correlational analysis. Resting perfusion was significantly lower in CLI versus healthy subjects (P=0.0007). Intraclass correlation coefficients of 0.95 (healthy) and 0.93 (CLI) demonstrated excellent agreement between serial perfusion measurements. Correlational analysis, including healthy and CLI subjects, demonstrated a significant relationship between ankle–brachial index and SPECT/CT (P=0.01); however, this relationship was not significant for diabetic CLI patients only (P=0.2).

Conclusions:

SPECT/CT imaging assesses regional foot perfusion and detects abnormalities in microvascular perfusion that may be undetectable by conventional ankle–brachial index in patients with diabetes mellitus. SPECT/CT may provide a novel approach for evaluating responses to targeted therapies.

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.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

[Differentiated treatment of patients with diabetic foot syndrome at the stage of specialized surgical care]

AIM

To assess 1-year results of differentiated treatment of patients with diabetic foot syndrome (DFS) who were included into 3-year register of diabetic foot outpatient practice (DFOP).

MATERIAL AND METHODS

It was performed retrospective analysis of 570 patients with DFS (2015-2017): group I - neuropathic form (n=285), group II - neuroischemic form (n=285). Patients were classified according to Texas grade. Group I - 107 (37.5%) patients (BI-III); 91 (31.9%) patients (AII+BII-III). Diabetic osteoarthropathy was diagnosed in 97 (34.0%) cases. Group II included 113 (45.2%) patients with DI-III and 171 (60.0%) patients with CII-II+DII-III. 308 patients received combined outpatient treatment (including limb off-loading in 88%), 195 patients - in-hospital surgical treatment (including endovascular procedures - 52), 67 patients - treatment at the place of residence. Postoperative follow-up was in diabetic foot outpatient practice. Statistical analysis of data was performed by using of Biostat software package.

RESULTS

In group I 1-year results are unknown in 76 (26.7%) patients. Epitheliazation was noted in 101 (35.4%) cases, persistent diabetic ulcer - in 27 (12.9%), small amputations - 16 (7.7%), high amputations - 2 (0.95%). In group II results are unknown in 29 (10.2%) patients. Epitheliazation occurred in 121 (47.3%) cases, persistent diabetic ulcer - 53 (20.7%), small amputations - 47 (18.4%), high amputations - in 35 (13.7%) cases.

CONCLUSION

DFOP is a key organizational unit of specialized medical care for patients with DFS. Regular follow-up of patients in DFOP and combined treatment at the stage of specialized surgical care allows to preserve limb in 99% of patients with neuropathic foot and in 86.3% of patients with neuroischemic foot.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

A portable three-dimensional photoacoustic tomography system for imaging of chronic foot ulcers

Background

Chronic leg ulcers affect approximately 6.5 million Americans and the disorder is associated with a range of serious complications. Since many chronic ulcers have underlying vascular insufficiency, accurate assessment of tissue perfusion is critical to treatment planning and post-surgical monitoring. However, existing clinical tests fail to meet this need in practice due to their low sensitivity or accuracy.

Methods

In this paper, we introduce a portable photoacoustic tomography (PAT) system for wound assessment. Since hemoglobin serves as the major endogenous contrast at near-infrared wavelengths, PAT provides label-free, three-dimensional (3D) imaging of hemoglobin distribution, which is closely related to blood perfusion. The proposed system consists of a 128-element linear transducer array, a data acquisition (DAQ) system, and a pulsed Nd:YAG laser source, all mounted on a portable cart for easy clinical testing.

Results

We validated our system through both phantom and human imaging studies. The phantom imaging results indicate that the system's spatial resolution ranges from 0.5 mm along the axial direction to 1.3 mm along the elevational direction. The healthy volunteer result shows clear foot vasculature, indicating good perfusion. The preliminary patient imaging results agree very well with the clinical test, demonstrating that PAT has a high potential for assessing the circulation around the wound.

Conclusions

We believe that our technique will be a valuable tool for assessing tissue perfusion and guiding wound treatment in vascular clinics.

Limb salvage in diabetic foot disease: A classification to aid successful reconstruction

Diabetes is a global epidemic. If poorly managed, innocuous injury in a diabetic foot leads to intractable ulceration, bone and joint destruction and subsequent major amputation. It is estimated that every week in the UK there are 100 lower limb amputations of which 80 could have been prevented had diabetes been better managed. It is widely recognised that prevention is critical; nonetheless diabetic foot lesions continue to increase in prevalence. Reconstruction of diabetic foot lesions has a dismal reputation despite promising published work. Reconstruction in the correctly chosen patient can be successful. Multiple classification systems and scores have been published, but these do not guide the clinician as to which lesions are reconstructible, and those in which attempts to salvage are futile. These patients would be better served with primary amputation. A tertiary referral centre's experience of diabetic foot reconstruction over 7 years is presented in a series of 22 consecutive patients who were assessed using a new classification system. Twenty-four flaps were performed all of which were either complex (n = 7) or complicated (n = 17) wounds as per our classification. Five patients (22%) had donor site healing problems, but only one flap (5%) in the series failed. Average follow-up was 23 months (range 4-75 months) and all patients were ambulant at discharge. Our simple classification system and aggressive approach to excision and reconstruction of diabetic foot lesions is a useful adjunct to existing systems, and helps promote the cause that limb salvage is warranted in these challenging cases when appropriately managed.

Angiosome perfusion of the foot: An old theory or a new issue?

The angiosome concept of foot perfusion was conceived based on anatomical studies of arterial circulation and used for planning surgical procedures, tissue reconstruction, and amputation. Its application is relevant in diabetic patients with critical limb ischemia and nonhealing foot ulcer or amputation. An understanding of foot angiosome anatomy is useful for predicting healing and planning arterial revascularization. A review of the literature, including the most recent systematic reviews and meta-analyses, indicates improved wound healing is achieved when the angiosome concept is followed. The greatest value of angiosome-based revascularization is in patients with lesion(s) limited to a single angiosome, or to achieve optimal healing of amputation sites. Future research should focus on proper identification of (imaging) modalities to determine the hemodynamic and functional changes before and after revascularization, thus identifying the "real" angiosome and directing optimal therapy.

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.

A Review of Distribution of Atherosclerosis in the Lower Limb Arteries of Patients With Diabetes Mellitus and Peripheral Vascular Disease

OBJECTIVE

There is a generally accepted hypothesis that patients with diabetes mellitus (DM) have a higher burden of atherosclerotic disease below the knee compared to patients without DM (NDM). The aim of this review was to summarize the evidence regarding this hypothesis.

METHODS

The literature was searched for papers that compared the anatomical distribution of atherosclerotic disease in patients with DM and those without using radiological imaging. Search terms used included "diabetes mellitus," "peripheral vascular disease," "distribution of disease," "angiography," "computed tomography angiography," and "magnetic resonance angiography." Where possible, the number of patients with disease in each arterial segment was extracted and included in a forest plot. A descriptive approach was taken when this was not possible or a scoring system was used.

RESULTS

Fourteen studies were included in the review and it was possible to summarize data from 9 of these in a forest plot. Fifteen different arterial segments were described; however, the most commonly used segments that differentiated between proximal and distal disease were aortoiliac (A-I; DM = 466 patients, NDM = 458), femoropopliteal (F-P; DM = 568, NDM = 585), tibial (DM = 306, NDM = 417). The resulting forest plot showed that those with DM were significantly less likely to have disease in the A-I segment (odds ratio [OR]: 0.25 [0.15-0.42]) and significantly more likely to have disease in the tibial segment (OR 1.94 [1.27-2.96]). In the DM group, there was a trend toward relative sparing in the F-P segment, but this does not reach significance (0.66 [0.33-1.31]).

CONCLUSIONS

These results support the hypothesis that patients with DM are more likely to have atherosclerotic disease in the tibial vessels than NDM. There is however limited information on how individual vessels are affected. Further information on this and a greater understanding of why the distal vessels are more affected are avenues for future research.

The Impact of Decline in Activities of Daily Living (ADL) of Patients With Critical Limb Ischemia (CLI) After Endovascular Treatment

BACKGROUND

Certain patients with critical limb ischemia (CLI) experience significant decline in activities of daily living (ADL) during hospitalization. The prognosis of decline in ADL during hospitalization remains unknown.

METHODS

A retrospective analysis was performed on collected data of patients with CLI treated by endovascular treatment between April 2007 and December 2015. We evaluated CLI in patients ADL at the time of hospitalization and after discharge using the Barthel index. We classified all patients into patients with decline in ADL and stable in ADL and compared clinical outcomes (cumulative incidence of wound healing, amputation-free survival at 1 year) between the 2 groups.

RESULTS

Two hundred and fifty-five consecutive patients with CLI (221 limbs), who underwent successful endovascular intervention, were enrolled in this study. Of all patients, 22 patients were classified into the decline group. The prevalence of wound, Ischemia, foot infection (WIfI) classification high grade was higher in the decline group (30.7% vs 63.6%; P < .01). The wound healing rates were worse in the decline group than in the stable group (40% vs 78% at 1 year; P < .01). The same trends were observed in the amputation-free survival (37% vs 78%; P < .01). After multivariate analysis, decline in ADL was an independent predictor of wound healing and amputation-free survival (odds ratio [OR]: 2.85, 95% confidence interval [CI]: 1.61-3.35, P < .01; OR: 2.46, 95% CI: 1.26-4.53, P = .01).

CONCLUSIONS

Patients with CLI with decline in ADL during hospitalization were found to have a poor prognosis suggesting that a decline in ADL may affect the clinical outcomes.

Pilot Assessment of the Angiosome Concept by Intra-operative Fluorescence Angiography After Tibial Bypass Surgery

OBJECTIVES

The "angiosome" concept as a model for decision making in revascularisation of patients with critical limb ischaemia (CLI) has been subject to lively discussion in recent years. The aim of this prospective pilot study was to use intra-operative fluorescence angiography to provide further data on the angiosome concept on the level of microcirculation after tibial bypass surgery.

DESIGN, MATERIALS, AND METHODS

This was a prospective analysis of 40 patients presenting with CLI Rutherford stage IV to VI before and after tibial bypass surgery. The macrocirculation was measured by the ankle brachial index. Skin microcirculation was assessed by intra-operative fluorescence angiography. The alteration of microcirculation was compared in direct and indirect revascularised angiosomes. Clinical follow-up investigations were performed and the wound healing rate was compared between the different revascularisation methods.

RESULTS

Cumulated microcirculation parameters showed a significant improvement after surgery (ingress, ingress rate p<.001). Likewise, general microcirculatory improvement was observed in each foot angiosome after revascularisation, regardless of the tibial artery revascularised. Furthermore, a comparison of the direct (DR) and the indirect revascularised (IR) angiosomes did not show a significant difference concerning the improvement of microcirculation (difference DR-IR, ingress: 1.69, 95% CI 71.73-75.11; ingress rate: 0.08, 95% CI -12.91 to 13.07). The wound healing rate was similar in both groups, although the time to wound healing was faster by on average 2.5 months in the DR group (p=.083).

CONCLUSION

Microcirculatory improvement was seen over the whole foot after tibial bypass. Therefore, fluorescence angiography is a promising tool to evaluate the angiosome concept in future larger studies. Clinicaltrials.gov: NCT03012750.

The evaluation of contralateral foot circulation after unilateral revascularization procedures using indocyanine green angiography

The aim of the present study is to assess the effects of unilateral revascularization on the contralateral foot circulation using indocyanine green (ICG). From January 2016 to April 2016, a total of twenty-one patients were included in this study. The patients underwent elective unilateral revascularization at our institution and we evaluated the feet circulation by indocyanine green angiography (ICGA) tests preoperatively and postoperatively. The ICGA parameters included the magnitude of intensity from the onset of ICG to the maximum intensity (I_max), the time from the onset of ICG to the maximum intensity (T_max), and the time required to reach the half maximum intensity from the onset of ICG (T_1/2). There were significant differences in the treated limb T_max (P = 0.016) and T_1/2 (P = 0.013) values and in the contralateral limb T_max (P = 0.013), and T_1/2 (P < 0.001) values on the perioperative ICGA tests. These results reflect the increase in skin perfusion in the treated limb and the decrease in skin perfusion in the contralateral limb. Unilateral revascularization decreases contralateral foot circulation. The preoperative contralateral lesion should be evaluated when revascularization is performed.

Infrapopliteal angioplasty using a combined angiosomal reperfusion strategy

Introduction

Infra-popliteal angioplasty continues to be widely performed with minimal evidence to guide practice. Endovascular device selection is contentious and there is even uncertainty over which artery to treat for optimum reperfusion. Direct reperfusion (DR) targets the artery supplying the ischaemic tissue. Indirect reperfusion (IR) targets an artery supplying collaterals to the ischaemic area. Our unit practice for the last eight years has been to attempt to open all tibial arteries at the time of angioplasty. When successful, this results in both direct and indirect; or combined reperfusion (CR). The aim was to review the outcomes of CR and compare them with DR or IR alone.

Methods

An eight year retrospective review from a single unit of all infra-popliteal angioplasties was undertaken. Wound healing, limb salvage, amputation-free and overall survival data as well as re-intervention rates were captured for all patients. Subgroup analysis for diabetics was undertaken. Kaplan Meier curves are presented for survival outcomes. All odds and hazard ratios (HR) and p values were corrected for bias from confounders using multivariate analysis.

Results

250 procedures were performed: 22 (9%) were CR; 115 (46%) DR and 113 (45%) IR. Amputation-free survival (HR 0.504, p = 0.039) and re-intervention and amputation-free survival (HR 0.414, p = 0.005) were significantly improved in patients undergoing CR compared to IR. Wound healing was similarly affected by reperfusion strategy (OR = 0.35, p = 0.047). Effects of CR over IR were similar when only diabetic patients were considered.

Conclusions

Combined revascularisation can only be achieved in approximately 10% of patients. However, when successful, it results in significant improvements in wound healing and amputation-free survival over simple indirect reperfusion techniques.

Clinical effects of single or double tibial artery revascularization in critical limb ischemia patients with tissue loss

OBJECTIVE

The achievement of single vessel inflow to the wound is an acceptable end point of peripheral vascular intervention for patients with critical limb ischemia (CLI) with tissue loss. However, CLI patients often have multitibial artery lesions. We evaluated the clinical effects of single or double tibial artery revascularization for CLI patients.

METHODS

This study was conducted retrospectively in a single center. Between April 2007 and January 2015, we treated 123 CLI patients (137 limbs) who had lesions in both the anterior tibial artery and the posterior tibial artery. Of these, single tibial artery (anterior or posterior tibial artery) revascularization was performed in 84 limbs (group S) and double tibial artery (both anterior and posterior tibial arteries) revascularization was performed in 53 limbs (group D).

RESULTS

The wound healing rate was significantly higher (87% vs 79%; P = .003), the time to wound healing was shorter (median, 83 vs 142 days; P = .01), and the repeat peripheral vascular intervention rate was lower (15% vs 35%; P = .03) in group D than in group S. The wound healing rate was nearly similar between the 2 groups in patients with a low clinical stage as assessed by Society for Vascular Surgery Wound, Ischemia, and foot Infection (90% in group D vs 93% in group S; P = .20); however, the wound healing rate was significantly higher in group D in patients with a high clinical stage (85% vs 72%; P = .007).

CONCLUSIONS

The achievement of double vessel inflows to the wound by double tibial artery revascularization positively affects wound healing, particularly in severe CLI patients.