Prognostic factors after open and endovascular repair for infected native aneurysms of the abdominal aorta and common iliac artery.

OBJECTIVE: Infected native aneurysms (INAs) of the abdominal aorta and iliac arteries are uncommon, but potentially fatal. Endovascular aneurysm repair (EVAR) has recently been introduced as a durable treatment option, with outcomes comparable to those yielded by conventional open repair. However, owing to the rarity of the disease, the strengths and limitations of each treatment remain uncertain. The present study aimed to separately assess post-open repair and post-EVAR outcomes and to clarify factors affecting the short-term and late prognosis after each treatment. METHODS: Using a nationwide clinical registry, we investigated 600 patients treated with open repair and 226 patients treated with EVAR for INAs of the abdominal aorta and/or common iliac artery. The relationships between preoperative or operative factors and postoperative outcomes, including 90-day and 3-year mortality and persistent or recurrent aneurysm-related infection, were examined. RESULTS: Prosthetic grafts were used in >90% of patients treated with open repair, and in situ and extra-anatomic arterial reconstruction was performed in 539 and 57 patients, respectively. Preoperative anemia and imaging findings suggestive of aneurysm-enteric fistula were independently associated with poor outcomes in terms of both 3-year mortality (hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.01-2.62; P = .046, and HR, 2.24; 95% CI, 1.12-4.46; P = .022, respectively) and persistent or recurrent infection (odds ratio [OR], 2.16; 95% CI, 1.04-4.49; P = .039, and OR, 4.96; 95% CI, 1.81-13.55; P = .002, respectively) after open repair, whereas omental wrapping or packing and antibiotic impregnation of the prosthetic graft for in situ reconstruction contributed to improved 3-year survival (HR, 0.60; 95% CI, 0.39-0.92; P = .019, and HR, 0.53; 95% CI, 0.32-0.88; P = .014, respectively). Among patients treated with EVAR, abscess formation adjacent to the aneurysm was significantly associated with the occurrence of persistent or recurrent infection (OR, 2.24; 95% CI, 1.06-4.72; P = .034), whereas an elevated preoperative white blood cell count was predictive of 3-year mortality (HR, 1.77; 95% CI, 1.00-3.13; P = .048). CONCLUSIONS: Profiles of prognostic factors differed between open repair and EVAR in the treatment of INAs of the abdominal aorta and common iliac artery. Open repair may be more suitable than EVAR for patients with concurrent abscess formation.

Effectiveness of bedside investigations to diagnose peripheral artery disease among people with diabetes mellitus: A systematic review.

As a progressive disease process, early diagnosis and ongoing monitoring and treatment of lower limb peripheral artery disease (PAD) is critical to reduce the risk of diabetes-related foot ulcer (DFU) development, non-healing of wounds, infection and amputation, in addition to cardiovascular complications. There are a variety of non-invasive tests available to diagnose PAD at the bedside, but there is no consensus as to the most diagnostically accurate of these bedside investigations or their reliability for use as a method of ongoing monitoring. Therefore, the aim of this systematic review was to first determine the diagnostic accuracy of non-invasive bedside tests for identifying PAD compared to an imaging reference test and second to determine the intra- and inter-rater reliability of non-invasive bedside tests in adults with diabetes. A database search of Medline and Embase was conducted from 1980 to 30 November 2022. Prospective and retrospective investigations of the diagnostic accuracy of bedside testing in people with diabetes using an imaging reference standard and reliability studies of bedside testing techniques conducted in people with diabetes were eligible. Included studies of diagnostic accuracy were required to report adequate data to calculate the positive likelihood ratio (PLR) and negative likelihood ratio (NLR) which were the primary endpoints. The quality appraisal was conducted using the Quality Assessment of Diagnostic Accuracy Studies and Quality Appraisal of Reliability quality appraisal tools. From a total of 8517 abstracts retrieved, 40 studies met the inclusion criteria for the diagnostic accuracy component of the review and seven studies met the inclusion criteria for the reliability component of the review. Most studies investigated the diagnostic accuracy of ankle -brachial index (ABI) (N = 38). In people with and without DFU, PLRs ranged from 1.69 to 19.9 and NLRs from 0.29 to 0.84 indicating an ABI <0.9 increases the likelihood of disease (but the extent of the increase ranges from a small to large amount) and an ABI within the normal range (≥0.90 and <1.3) does not exclude PAD. For toe-brachial index (TBI), a threshold of <0.70 has a moderate ability to rule PAD in and out; however, this is based on limited evidence. Similarly, a small number of studies indicate that one or more monophasic Doppler waveforms in the pedal arteries is associated with the presence of PAD, whereas tri- or biphasic waveform suggests that PAD is less likely. Several forms of bedside testing may also be useful as adjunct tests and 7 studies were identified that investigated the reliability of bedside tests including ABI, toe pressure, TBI, transcutaneous oxygen pressure (TcPO2 ) and pulse palpation. Inter-rater reliability was poor for pulse palpation and moderate for TcPO2. The ABI, toe pressure and TBI may have good inter- and intra-rater reliability, but margins of error are wide, requiring a large change in the measurement for it to be considered a true change rather than error. There is currently no single bedside test or a combination of bedside tests that has been shown to have superior diagnostic accuracy for PAD in people with diabetes with or without DFU. However, an ABI <0.9 or >1.3, TBI of <0.70, and absent or monophasic pedal Doppler waveforms are useful to identify the presence of disease. The ability of the tests to exclude disease is variable and although reliability may be acceptable, evidence of error in the measurements means test results that are within normal limits should be considered with caution and in the context of other vascular assessment findings (e.g., pedal pulse palpation and clinical signs) and progress of DFU healing.

Effectiveness of revascularisation for the ulcerated foot in patients with diabetes and peripheral artery disease: A systematic review.

INTRODUCTION: Peripheral artery disease (PAD) is associated with an increased likelihood of delayed or non-healing of a diabetes-related foot ulcer, gangrene, and amputation. The selection of the most effective surgical technique for revascularisation of the lower limb in this population is challenging and there is a lack of conclusive evidence to support the choice of intervention. This systematic review aimed to determine, in people with diabetes and tissue loss, if direct revascularisation is superior to indirect revascularisation and if endovascular revascularisation is superior to open revascularisation for the outcomes of wound healing, minor or major amputation, and adverse events including mortality. METHODS: Title and abstract searches of Medline, Embase, PubMed, and EBSCO were conducted from 1980 to 30th November 2022. Cohort and case-control studies and randomised controlled trials reporting comparative outcomes of direct (angiosome) revascularisation (DR) and indirect revascularisation (IR) or the comparative outcomes of endovascular revascularisation and open or hybrid revascularisation for the outcomes of healing, minor amputation, and major amputation in people with diabetes, PAD and tissue loss (including foot ulcer and/or gangrene) were eligible. Methodological quality was assessed using the Cochrane risk-of-bias tool for randomised trials, the ROBINS-I tool for non-randomised studies, and Newcastle-Ottawa Scale for observational and cohort studies where details regarding the allocation to intervention groups were not provided. RESULTS: From a total 7086 abstracts retrieved, 26 studies met the inclusion criteria for the comparison of direct angiosome revascularisation (DR) and indirect revascularisation (IR), and 11 studies met the inclusion criteria for the comparison of endovascular and open revascularisation. One study was included in both comparisons. Of the included studies, 35 were observational (31 retrospective and 4 prospective cohorts) and 1 was a randomised controlled trial. Cohort study quality was variable and generally low, with common sources of bias related to heterogeneous participant populations and interventions and lack of reporting of or adjusting for confounding factors. The randomised controlled trial had a low risk of bias. For studies of DR and IR, results were variable, and it is uncertain if one technique is superior to the other for healing, prevention of minor or major amputation, or mortality. However, the majority of studies reported that a greater proportion of participants receiving DR healed compared with IR, and that IR with collaterals may have similar outcomes to DR for wound healing. For patients with diabetes, infrainguinal PAD, and an adequate great saphenous vein available for use as a bypass conduit who were deemed suitable for either surgical procedure, an open revascularisation first approach was superior to endovascular therapy to prevent a major adverse limb event or death (Hazard Ratio: 0.72; 95% CI 0.61-0.86). For other studies of open and endovascular approaches, there was generally no difference in outcomes between the interventions. CONCLUSIONS: The majority of available evidence for the effectiveness of DR and IR and open and endovascular revascularisation for wound healing and prevention of minor and major amputation and adverse events including mortality in people with diabetes, PAD and tissue loss is inconclusive, and the certainty of evidence is very low. Data from one high quality randomised controlled trial supports the use of open over endovascular revascularisation to prevent a major limb event and death in people with diabetes, infrainguinal disease and tissue loss who have an adequate great saphenous vein available and who are deemed suitable for either approach.

Performance of non-invasive bedside vascular testing in the prediction of wound healing or amputation among people with foot ulcers in diabetes: A systematic review.

INTRODUCTION: The presence of peripheral artery disease (PAD) confers a significantly increased risk of failure to heal and major lower limb amputation for people with diabetes-related foot ulcer (DFU). Determining performance of non-invasive bedside tests for predicting likely DFU outcomes is therefore key to effective risk stratification of patients with DFU and PAD to guide management decisions. The aim of this systematic review was to determine the performance of non-invasive bedside tests for PAD to predict DFU healing, healing post-minor amputation, or need for minor or major amputation in people with diabetes and DFU or gangrene. METHODS: A database search of Medline and Embase was conducted from 1980 to 30 November 2022. Prospective studies that evaluated non-invasive bedside tests in patients with diabetes, with and without PAD and foot ulceration or gangrene to predict the outcomes of DFU healing, minor amputation, and major amputation with or without revascularisation, were eligible. Included studies were required to have a minimum 6-month follow-up period and report adequate data to calculate the positive likelihood ratio (PLR) and negative likelihood ratio for the outcomes of DFU healing, and minor and major amputation. Methodological quality was assessed using the Quality in Prognosis Studies tool. RESULTS: From 14,820 abstracts screened 28 prognostic studies met the inclusion criteria. The prognostic tests evaluated by the studies included: ankle-brachial index (ABI) in 9 studies; ankle pressures in 10 studies, toe-brachial index in 4 studies, toe pressure in 9 studies, transcutaneous oxygen pressure (TcPO2 ) in 7 studies, skin perfusion pressure in 5 studies, continuous wave Doppler (pedal waveforms) in 2 studies, pedal pulses in 3 studies, and ankle peak systolic velocity in 1 study. Study quality was variable. Common reasons for studies having a moderate or high risk of bias were poorly described study participation, attrition rates, and inadequate adjustment for confounders. In people with DFU, toe pressure ≥30 mmHg, TcPO2 ≥25 mmHg, and skin perfusion pressure of ≥40 mmHg were associated with a moderate to large increase in pretest probability of healing in people with DFU. Toe pressure ≥30 mmHg was associated with a moderate increase in healing post-minor amputation. An ABI using a threshold of ≥0.9 did not increase the pretest probability of DFU healing, whereas an ABI <0.5 was associated with a moderate increase in pretest probability of non-healing. Few studies investigated amputation outcomes. An ABI <0.4 demonstrated the largest increase in pretest probability of a major amputation (PLR ≥10). CONCLUSIONS: Prognostic capacity of bedside testing for DFU healing and amputation is variable. A toe pressure ≥30 mmHg, TcPO2 ≥25 mmHg, and skin perfusion pressure of ≥40 mmHg are associated with a moderate to large increase in pretest probability of healing in people with DFU. There are little data available evaluating the prognostic capacity of bedside testing for healing after minor amputation or for major amputation in people with DFU. Current evidence suggests that an ABI <0.4 may be associated with a large increase in risk of major amputation. The findings of this systematic review need to be interpreted in the context of limitations of available evidence, including varying rates of revascularisation, lack of post-revascularisation bedside testing, and heterogenous subpopulations.

The intersocietal IWGDF, ESVS, SVS guidelines on peripheral artery disease in people with diabetes and a foot ulcer.

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this guideline the IWGDF, the European Society for Vascular Surgery and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development, and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

One-Year Clinical Outcomes and Prognostic Factors Following Revascularization in Patients With Acute Limb Ischemia　- Results From the RESCUE ALI Study.

BACKGROUND: Acute limb ischemia (ALI) is a limb- and life-threatening condition and urgent treatment including revascularization should be offered to patients unless the limb is irreversibly ischemic. The aim of this study was to investigate 1-year clinical outcomes and prognostic factors following revascularization in patients with ALI.Methods and Results: A retrospective, multicenter, nonrandomized study examined 185 consecutive patients with ALI treated by surgical revascularization (SR), endovascular revascularization (ER), or hybrid revascularization (HR) in 6 Japanese medical centers from January 2015 to August 2021. The 1-year amputation-free survival (AFS) rate was estimated to be 69.2% (95% confidence interval [CI], 62.8-76.2%). There were no significant differences among SR, ER, and HR regarding both technical success and perioperative complications. Multivariate analysis revealed that Rutherford category IIb and III ischemia (hazard ratio [HR]: 1.86; 95% CI: 1.06-3.25), supra- to infrapopliteal lesion (HR: 2.06; 95% CI: 1.08-3.95), and technical failure (HR: 2.58; 95% CI: 1.49-4.46) were independent risk factors for 1-year AFS. CONCLUSIONS: Rutherford category IIb and III ischemia, supra- to infrapopliteal lesions, and technical failures were identified as independent risk factors for 1-year AFS. Furthermore, patients with multiple risk factors had a lower AFS rate.

Role of Helicopter Transfer and Cloud-Type Imaging for Acute Type A Aortic Dissection.

BACKGROUND: This study explored if long-distance transfer was safe for patients suffering from acute aortic dissection type A (AADA) and also analyzed the effectiveness of helicopter transfer and cloud-type imaging transfer systems for such patients in northern Hokkaido, Japan. METHODS AND RESULTS: The study included 112 consecutive patients who underwent emergency surgical treatment for AADA from April 2014 to September 2020. The patients were divided into two groups according to the location of referral source hospitals: the Asahikawa city group (group A, n = 49) and the out-of-the-city group (group O, n = 63). Use of helicopter transfer (n = 13) and cloud-type telemedicine (n = 20) in group O were reviewed as subanalyses.Transfer distance differed between groups (4.2 ± 3.5 km in group A vs 107.3 ± 69.2 km in group O; p = 0.0001), but 30-day mortality (10.2% in group A vs 7.9% in group O; p = 0.676) and hospital mortality (12.2% in group A vs 9.5% in group O; p = 0.687) did not differ. Operative outcomes did not differ with or without helicopter and cloud-type telemedicine, but diagnosis-to-operation time was shorter with helicopter (240.0 ± 70.8 vs 320.0 ± 78.5 minutes; p = 0.031) and telemedicine (242.0 ± 75.2 vs 319.0 ± 83.8 minutes; p = 0.007). CONCLUSION: We found that long-distance transfer did not impair surgical outcomes in AADA patients, and both helicopter transfer and cloud-type telemedicine system could contribute to the reduction of diagnosis-to-operation time in the large Hokkaido area. Further studies are mandatory to investigate if both the systems will improve clinical outcomes.

The intersocietal IWGDF, ESVS, SVS guidelines on peripheral artery disease in people with diabetes mellitus and a foot ulcer.

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Surgical Treatment for Popliteal Artery Entrapment Syndrome in Japan: a Retrospective, Multicentre Study Using a National Clinical Registry.

OBJECTIVE: Surgical treatment is an established method for popliteal artery entrapment syndrome (PAES), which, however, mainly derives from single centre experiences where PAES cases are centralised and treated periodically. This study evaluated clinical outcomes of surgical treatment for PAES in a clinical setting where PAES cases were not centralised. METHODS: Multicentre, retrospective cohort study using a national clinical registry. From a Japanese nationwide clinical registry, data for patients who underwent surgical treatment for PAES between 2013 and 2018, including 58 limbs from 41 institutes, were retrieved and evaluated. Patency was analysed using Kaplan-Meier curves. RESULTS: The mean patient age was 36 ± 19 years, 78% were male, and the incidence of PAES was 0.24 limbs/centre/year, reflecting a clinical setting where PAES cases are not centralised. The most frequent arterial symptom was intermittent claudication (90%). Computed tomography was performed in 57 limbs (98%) for the diagnosis, however active manoeuvres such as dorsiflexion and plantarflexion during the examination was performed in only 13 limbs (22%), and occlusion of the popliteal artery was present in 38 limbs (66%) at diagnosis. Regarding surgical treatment, myotomy alone was performed in only seven limbs (12%), and other limbs were revascularised. Mean follow up was 26 ± 20 months, and surgical treatment was effective as it relieved symptoms in > 96% of limbs, with five year primary and secondary patency of the surgical treatment for PAES of 72% and 93%, respectively. CONCLUSION: Results of surgical treatment were acceptable even in a clinical setting where PAES cases were not centralised. However, a low incidence of active manoeuvres performed during the examination and a high incidence of occlusion at diagnosis suggests there may be delayed or underdiagnosis of PAES in Japan, and increased awareness for PAES is warranted.

The Intersocietal IWGDF, ESVS, SVS Guidelines on Peripheral Artery Disease in People With Diabetes Mellitus and a Foot Ulcer.

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Regenerative Effect of Umbilical Cord-Derived Mesenchymal Stromal Cells in a Rat Model of Established Limb Ischemia.

BACKGROUND: Although regenerative cell therapy is expected to be an alternative treatment for peripheral artery disease (PAD), many regenerative cell therapies have failed to show sufficient efficacy in clinical trials. Most preclinical studies have used acute ischemia models, despite PAD being a chronic disease. In addition, aging and atherosclerosis decrease the quality of a patient's stem cells. Therefore, using a non-acute ischemic preclinical model and stem cells with high regenerative potency are important for the development of effective regenerative therapy. In this study, we assessed the tissue regenerative potential of umbilical cord-derived mesenchymal stromal cells (UCMSCs), which could potentially be an ideal cell source, in a rat model of established ischemia.Methods and Results: The regenerative capacity of UCMSCs was analyzed in terms of angiogenesis and muscle regeneration. In vitro analysis showed that UCMSCs secrete high amounts of cytokines associated with angiogenesis and muscle regeneration. In vivo experiments in a rat non-acute ischemia model showed significant improvement in blood perfusion after intravenous injection of UCMSCs compared with injection of culture medium or saline. Histological analysis revealed UCMSCs injection enhanced angiogenesis, with an increased number of von Willebrand factor-positive microcapillaries, and improved muscle regeneration. CONCLUSIONS: These results suggest that intravenous administration of UCMSCs may be useful for treating patients with PAD.

Prediction Models for Two Year Overall Survival and Amputation Free Survival After Revascularisation for Chronic Limb Threatening Ischaemia.

OBJECTIVE: The aim of this study was to create prediction models for two year overall survival (OS) and amputation free survival (AFS) after revascularisation in patients with chronic limb threatening ischaemia (CLTI). METHODS: This was a retrospective analysis of prospectively collected multicentre registry data (JAPAN Critical Limb Ischaemia Database; JCLIMB). Data from 3 505 unique patients with CLTI who had undergone revascularisation from 2013 to 2017 were extracted from the JCLIMB for the analysis. The cohort was randomly divided into development (2 861 patients) and validation cohorts (644 patients). In the development cohort, multivariable risk models were constructed to predict two year OS and AFS using Cox proportional hazard regression analysis. These models were applied to the validation cohort and their performances were evaluated using Harrell's C index and calibration plots. RESULTS: Kaplan-Meier estimates of two year OS and AFS post-revascularisation in the whole cohort were 69% and 62%, respectively. Strong predictors for OS consisted of age, activity, malignant neoplasm, chronic kidney disease (CKD), congestive heart failure (CHF), geriatric nutritional risk index (GNRI), and sex. Strong predictors for AFS included age, activity, malignant neoplasm, CKD, CHF, GNRI, body temperature, white blood cells, urgent revascularisation procedure, and sex. Prediction models for two year OS and AFS showed good discrimination with Harrell's C indexes of 0.73 (95% confidence interval [CI] 0.69 - 0.77) and 0.72 (95% CI 0.68 - 0.76), respectively CONCLUSION: Prediction models for two year OS and AFS post-revascularisation in patients with CLTI were created. They can assist in determining treatment strategies and serve as risk adjustment modalities for quality benchmarking for revascularisation in patients with CLTI at each facility.

Impact of Dialysis Vintage and Renal Biomarkers on Mortality in Dialysis-Dependent Patients With Critical Limb Ischemia Undergoing Revascularization.

PURPOSE: Revascularization of both endovascular therapy (EVT) and surgical reconstruction improve clinical outcomes of patients with critical limb ischemia (CLI); however, treatment of dialysis-dependent patients with CLI is still challenging. This study aimed to investigate the impact of dialysis-related parameters on the risk of mortality in dialysis-dependent patients undergoing revascularization for CLI. MATERIALS AND METHODS: We retrospectively identified 274 dialysis-dependent patients with CLI (196 males; mean age 71 years), who underwent revascularization, from the clinical database of the surgical reconstruction vs peripheral intervention in patients with critical limb ischemia (SPINACH) study, which was a prospective, multicenter, observational study. Of these patients, 175 patients underwent EVT and 99 patients received surgical reconstruction. The current study evaluated the impact of dialysis vintage and renal biomarkers on the mortality rate of dialysis-dependent patients with CLI undergoing revascularization. RESULTS: During a mean follow-up period of 1.7 ± 1.1 years, 147 deaths were observed. The 3-year overall survival rate and its standard error were estimated to be 40.5% ± 8.1% using the Kaplan-Meier method. A Cox proportional hazard analysis revealed that dialysis vintage ≥4 years, serum creatinine levels <4.7 mg/dL, serum urea nitrogen ≥88 mg/dL, and calcium-phosphate product ≥62.6 mg2/dL2 were independent risk factors for mortality after adjustment for the detailed mortality risk score developed in the SPINACH study. Adding these parameters to the original mortality risk score slightly, but not significantly, increased the area under the time-dependent receiver operating characteristics curve from 0.74 (95% CI, 0.67 to 0.81) to 0.77 (0.71 to 0.84) (p=0.084), whereas continuous net reclassification improvement reached 0.75 (0.12 to 0.90) (p=0.027). CONCLUSION: We found that long dialysis vintage, low serum creatinine, high serum urea nitrogen, and high calcium-phosphate product were independently associated with the increased risk of mortality in dialysis-dependent patients with CLI undergoing revascularization.

Baseline and Updated Information on Nutritional Status in Patients With Chronic Limb Threatening Ischaemia Undergoing Revascularisation.

OBJECTIVE: The aim of this study was to assess the impact of baseline and updated nutritional status on prognosis in patients with chronic limb threatening ischaemia (CLTI) undergoing revascularisation. METHODS: The clinical database of the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia (SPINACH) study, a prospective, multicentre, observational study, was used. The current analysis included 499 patients who underwent endovascular therapy or surgical reconstruction for CLTI. Nutritional status at baseline was evaluated using the Geriatric Nutritional Risk Index (GNRI; baseline GNRI). A GNRI <82 points indicates major nutrition related risk. GNRI was also calculated at 1, 3, 6, 12, 24, and 36 months after revascularisation (updated GNRI). The association between baseline and updated GNRIs and the mortality risk was analysed with the Cox regression model. RESULTS: Mean ± standard deviation (SD) GNRI at baseline was 89.9 ± 9.8 points. The proportion of patients alive with a GNRI ≥82 points was 78% (95% confidence interval [CI] 74-81) at baseline but gradually decreased during follow up, finally reaching 19% (95% CI 0-42) at 36 months. In patients with a GNRI <82 points at baseline, a GNRI of ≥82 points was increased to 37% (95% CI 6-68) 12 months after revascularisation. In the multivariable analysis, baseline and updated GNRIs were associated with a reduced mortality risk independently of each other; the adjusted hazard ratios per 1 SD were 0.80 (95% CI 0.65-0.98; p = .031) and 0.66 (95% CI 0.49-0.91; p = .015), respectively. Similar findings were observed when nutritional status was evaluated using the Controlling Nutritional Stats (CONUT) score, except for the association between its updated value and mortality risk, which marginally lost significance. CONCLUSION: There was still room for improvement in nutritional status after revascularisation for patients with CLTI. Updated GNRI was associated with death independently of baseline GNRI.

Health Related Quality of Life Over Time After Revascularisation in Patients With Chronic Limb Threatening Ischaemia.

OBJECTIVE: Chronic limb threatening ischaemia (CLTI) decreases life expectancy and impairs health related quality of life (HR-QOL). Revascularisation is needed to relieve ischaemia and salvage limbs. Although a major goal of CLTI treatment is maintaining QOL, little information is available about changes of HR-QOL over time after revascularisation. HR-QOL with survival after revascularisation for CLTI was assessed. METHODS: The clinical database of the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia (SPINACH), a prospective multicentre observational study, was analysed. Outcome measures were disease specific QOL per the Vascular Quality of Life (VascuQOL) questionnaire and the Short Form (SF) 36 evaluated generic QOL, which were assessed at baseline and three, 12, 24, and 36 months. The outcome measure was change of QOL from baseline. The minimally important difference (half a standard deviation from baseline) was used as the cut off point for improved, worsened, and unchanged QOL. RESULTS: Overall QOL was improved in 61% of patients for the VascuQOL and approximately 40% for the SF-36 component summaries at three months. However, these proportion gradually decreased to 21% - 31% at three years. In contrast, the proportion of deceased patients gradually increased over the three year follow up. Multivariable analysis revealed that pre-operative non-ambulatory status was inversely associated with improved QOL for the three month VascuQOL and SF-36 mental component summary, and surgical reconstruction was positively associated with these measurements. Advanced age and renal failure were inversely associated with improved QOL for the SF-36 mental component summary and VascuQOL at one to three years. CONCLUSION: Revascularisation improved QOL. However, patients with non-ambulatory status exhibited a negative association with improved QOL at three months, and advanced age and renal failure limited benefits one to three years after revascularisation. Accumulating QOL data will be essential for post-revascularisation QOL estimation. Pre-operative assessment, including estimated QOL, is important in shared decision making for patient oriented outcomes in the treatment of CLTI patients.

Impact of homocysteine levels on mortality risk in patients with chronic limb-threatening ischemia undergoing revascularization.

The current study aimed to reveal the clinical impact of plasma homocysteine levels in chronic limb-threatening ischemia (CLTI) patients undergoing revascularization. This was a sub-analysis of a prospective multicenter registry of CLTI patients, named the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia (SPINACH) study. The current analysis included 192 non-dialysis-dependent CLTI patients who underwent revascularization for CLTI, and whose plasma homocysteine levels at baseline were available. The association of clinical characteristics with homocysteine levels was evaluated with the linear regression model. The association of homocysteine levels with the mortality risk was investigated using the Cox proportional hazards regression model. Cystatin C-based estimated glomerular filtration rate (eGFR) was independently associated with log-transformed homocysteine levels; the adjusted standardized regression coefficient (95% confidence interval) was - 0.432 (- 0.657 to - 0.253; P < 0.001). Homocysteine levels were significantly associated with the mortality risk in the univariate model (P = 0.017); the unadjusted hazard ratio was 1.71 (1.13-2.50) per twofold increase. The association was significantly attenuated when adjusted for cystatin C-based eGFR (P < 0.001); the hazard ratio adjusted for cystatin C-based eGFR was 1.28 (0.80-1.90; P = 0.29). An apparent association of homocysteine levels with an increased risk of mortality could be explained by renal dysfunction. Future studies will be needed to validate the current findings.

Predictive Model for Postoperative Ambulatory Function after Lower Extremity Bypass in Chronic Limb-Threatening Ischemia.

BACKGROUND: In chronic limb-threatening ischemia, maintenance or recovery of ambulatory function is an important goal of treatment. This study aimed to develop a predictive model for ambulatory ability 1 year after bypass based on preoperative risk factors, including the Wound, Ischemia, and foot Infection (WIfI) classification. METHODS: We analyzed 146 patients with chronic limb-threatening ischemia (154 limbs) who underwent bypass to below the knee arteries. The patients were classified into 2 groups based on ambulatory status 1 year postoperatively: postoperative ambulation (99 patients, 104 limbs) and postoperative nonambulation (47 patients, 50 limbs). Various factors associated with postoperative ambulation were analyzed and a predictive model of postoperative ambulation was developed. RESULTS: Multivariate logistic regression analysis detected preoperative nonambulatory status, functional nonindependence in daily living, older age, WIfI wound grade 3, chronic obstructive pulmonary disease, and hemodialysis as independent risk factors for postoperative nonambulation. The predictive scoring model (scores ranging from -5.0 to 4.4) comprising these risk factors discriminated the postoperative ambulatory status well: the probabilities of postoperative ambulatory ability were ≥85% in those with a score ≤-2, 50% in those with a score of zero, and ≤15% in those with a score ≥2. The area under the receiver operating characteristic curve was 0.898, indicating good performance of the model. CONCLUSIONS: Preoperative nonambulatory status, functional nonindependence, advanced age, high WIfI wound grade, chronic obstructive pulmonary disease, and hemodialysis were important predictors of postoperative nonambulatory status. The predictive model will help us identify patients who will benefit from bypass surgery.

Development of gene therapy with a cyclic adenosine monophosphate response element decoy oligodeoxynucleotide to prevent vascular intimal hyperplasia.

OBJECTIVE: Intimal hyperplasia (IH) is the main cause of therapeutic failure after vascular and endovascular surgery. However, there is currently no targeted therapy for the treatment of IH. We recently reported that the inhibition of cyclic adenosine monophosphate response element (CRE) binding protein (CREB) activation is important in vein graft IH. We focused on a decoy oligodeoxynucleotide (ODN) therapeutic strategy for suppressing IH as a clinical application. The objective of this study was to confirm the therapeutic effect of a CRE decoy ODN in an animal model as a novel therapy for preventing intimal hyperplasia as the first step of the preclinical study of our strategy. METHODS: We designed two phosphorothioate CREs and two scramble decoy ODNs and screened them using a CREB transcription assay to check their ability to bind to a CRE sequence. We chose a CRE decoy ODN with high first-binding ability and transfected it into vascular smooth muscle cells (VSMCs) in vitro. Proliferation and migration were assessed using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assays and modified Boyden chamber assays. We examined CRE activity using a luciferase reporter gene assay. We assessed the expression of messenger RNAs by quantitative real-time polymerase chain reaction. In a wire-injury mouse model (C57BL6, n = 6), CRE decoy ODN was transfected into the injured vessel wall using an ultrasound-sonoporation method in vivo. Mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) and four and a half LIM domains 5 (FHL5) expression of pregrafting vein remnants were assessed by immunohistologic analyses. RESULTS: Compared with scramble decoy ODN, the selected CRE decoy ODN could significantly decrease CRE activity (mean ± standard error of the mean: 0.20 ± 0.03 vs 1.00 ± 0.16, n = 6; P < .05) as shown by a luciferase reporter gene assay, VSMC proliferation (0.73 ± 0.04 vs 0.89 ± 0.02, n = 6; P < .05) and migration (96.4 ± 6.1 vs 311.4 ± 19.1 migrated VSMCs/well, n = 6; P < .05) after 24-hour transfection. The CRE decoy ODN significantly suppressed the formation of IH at injured vessel walls in an animal model, as analyzed by pathologic staining (0.20 ± 0.02 vs 0.56 ± 0.08, area of the intima/area of the artery vs the control after 21 days' transfection, n = 6; P < .05). Furthermore, MAPKAPK3 and FHL5, which are CREB activators, were significantly expressed in pregrafting vein remnants in diabetes mellitus patients. CONCLUSIONS: CREB-CRE signaling is an important mechanism of IH formation, and CRE decoy therapy can help preventing IH. This study is the first part of the preclinical study of our strategy.

Inhibitory Effects of PRG4 on Migration and Proliferation of Human Venous Cells.

BACKGROUND: Proteoglycan 4 (PRG4; lubricin) is a member of two gene co-expression network modules associated with human vein graft failure. However, little is known about PRG4 and the vascular system. Therefore, we have investigated the effects of recombinant human PRG4 (rhPRG4) on cell migration and proliferation in human veins. METHODS: Effects of rhPRG4 on cell migration, proliferation, and neointima formation were determined in human venous tissue and cultured venous smooth muscle cells (SMCs), adventitial cells, and endothelial cells. Expression of PRG4 by cultured human saphenous veins, failed vein grafts, and varicose veins was determined by immunostaining or Western blotting. RESULTS: Limited expression of PRG4 in fresh saphenous veins was dramatically increased around medial SMCs after culture ex vivo. rhPRG4 inhibited the migration of cultured SMCs, adventitial cells, and endothelial cells, as well as the proliferation of endothelial cells. rhPRG4 also inhibited the migration of SMCs and adventitial cells from tissue explants, but there was no effect on cell proliferation or neointima formation in ex vivo whole veins. Finally, PRG4 was largely absent in two examples of venous pathology, that is, failed human vein grafts and varicose veins. CONCLUSIONS: Although rhPRG4 can inhibit the migration of venous SMCs, endothelial cells, and adventitial cells, and the proliferation of endothelial cells, PRG4 was only increased around medial SMCs in veins after ex vivo culture. PRG4 was not observed around medial SMCs in failed human vein grafts and varicose veins, suggesting the possibility that a failure of PRG4 upregulation may promote these pathologies.

Limb-Based Patency After Surgical vs Endovascular Revascularization in Patients with Chronic Limb-Threatening Ischemia.

PURPOSE: To determine whether limb-based patency (LBP) after infrainguinal revascularization for chronic limb-threatening ischemia (CLTI) is similar between bypass surgery and endovascular therapy (EVT). MATERIALS AND METHODS: The database for the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) study was interrogated to identify 130 patients (mean age 73±8 years; 94 men) who underwent bypass surgery and 271 patients (mean age 74±10 years; 178 men) who underwent EVT alone. Skin perfusion pressure (SPP) and the ankle-brachial index (ABI) were measured before the procedure and at 0, 1, and 3 months after revascularization. The outcome measure was hemodynamically evaluated LBP (SPP ≥10 mm Hg or ABI ≥0.1) maintained over the first 3 months after treatment. Any reintervention or major amputation was regarded as loss of LBP. The associations between the revascularization strategy (bypass vs EVT) and between the preoperative characteristics and the study outcome (ie, SPP- or ABI-based LBP), were determined using generalized linear mixed models with a logit link function. Patency rates are presented with the 95% confidence interval (CI). RESULTS: The bypass surgery group had a higher stage of limb severity (WIfI) and anatomic complexity (GLASS) than the EVT group, whereas the EVT group had a higher prevalence of heart failure. Both SPP- and ABI-based LBP rates were higher in the bypass group than in the EVT group. SPP-based LBP rates at 3 months were 73.8% (95% CI 63.4% to 84.2%) in the bypass group and 46.2% (95% CI 38.5% to 53.8%) in the EVT group; the corresponding ABI-based LBP rates were 71.5% (95% CI 61.8% to 81.2%) and 44.0% (95% CI 37.3% to 50.7%). CONCLUSION: LBP is an important concept in the new global vascular guidelines for assessing the anatomic and hemodynamic status of CLTI patients. The present study found that LBP was significantly lower in the EVT group vs the bypass surgery group.