Long-Term Results of Treatment for Critical Limb Ischemia

A Multicenter Prospective Interventional Trial of Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans

BACKGROUND

Thromboangiitis obliterans (TAO) can lead to the development of critical limb-threatening ischemia (CLTI). Despite conventional treatments, such as smoking cessation or revascularization, young patients (<50 years) still require limb amputation. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation has been tested and shown to have reasonable efficacy in CLTI. In this multicenter prospective clinical trial, we evaluated the safety and efficacy of BM-MNC implantation in CLTI patients with TAO.Methods and Results: We enrolled 22 CLTI patients with skin perfusion pressure (SPP) <30 mmHg. The primary endpoint of this trial is the recovery of SPP in the treated limb after a 180-day follow-up period. Secondary endpoints include the pain scale score and transcutaneous oxygen pressure (TcPO2). One patient dropped out during follow-up, leaving 21 patients (mean age 48 years, 90.5% male, Fontaine Class IV) for analysis. BM-MNC implantation caused no serious adverse events and increased SPP by 1.5-fold compared with baseline. Surprisingly, this effect was sustained over the longer term at 180 days. Secondary endpoints also supported the efficacy of this novel therapy in relieving pain and increasing TcPO2. Major amputation-free and overall survival probabilities at 3 years among all enrolled patients were high (95.5% and 89.5%, respectively).

CONCLUSIONS

BM-MNC implantation showed safety and significant efficacy in CLTI patients with TAO.

Therapeutic angiogenesis using autologous adipose-derived regenerative cells in patients with critical limb ischaemia in Japan: a clinical pilot study

Adipose-derived regenerative cell (ADRC) is a promising alternative source of autologous somatic stem cells for the repair of damaged tissue. This study aimed to assess the safety and feasibility of autologous ADRC implantation for therapeutic angiogenesis in patients with critical limb ischaemia (CLI). A clinical pilot study—Therapeutic Angiogenesis by Cell Transplantation using ADRCs (TACT-ADRC) study—was initiated in Japan. Adipose tissue was obtained by ordinary liposuction method. Isolated ADRCs were injected into the ischaemic limb. We performed TACT-ADRC procedure in five patients with CLI. At 6 months, no adverse events related to the TACT-ADRC were observed. No patients required major limb amputation, and ischaemic ulcers were partly or completely healed during the 6-month follow-up. In all cases, significant clinical improvements were seen in terms of rest pain and 6-min walking distance. Numbers of circulating CD34⁺ and CD133⁺ cells markers of progenitor cell persistently increased after ADRC implantation. The ratio of VEGF-A₁₆₅b (an anti-angiogenic isoform of VEGF) to total VEGF-A in plasma significantly decreased after ADRC implantation. In vitro experiments, cultured with ADRC-conditioned media (CM) resulted in increased total VEGF-A and decreased VEGF-A₁₆₅b in C2C12 cells, but not in macrophages. ADRC-CM also increased CD206⁺ cells expression and decreased TNF-α in macrophages. Autologous ADRC implantation was safe and effective in patients with CLI and could repair damaged tissue via its ability to promote angiogenesis and suppress tissue inflammation.

Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans - Study Protocol for a Multicenter Prospective Interventional Trial

Background: Patients with thromboangiitis obliterans (TAO) can develop critical limb-threatening ischemia (CLTI) and require limb amputation. Smoking cessation and exercise therapy are recommended as standard treatments, and revascularization by bypass surgery or endovascular therapy (EVT) is required for patients with CLTI. However, there are many cases in which revascularization is difficult because of vascular characteristics, and the patency rate after revascularization remains unsatisfactory. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation is used clinically, with many trials demonstrating long-term efficacy and safety of the technique in patients with CLTI, especially that caused by TAO. To expand the use of BM-MNCs implantation in clinical practice, further evidence is required in patients with CLTI caused by TAO.

Methods and Results: This trial is a multicenter, prospective, non-randomized interventional trial of an Advanced Medicine B treatment approach. We aim to enroll 25 patients aged 20–80 years with Fontaine classification Stage III or IV, who will undergo BM-MNC implantation. The primary endpoint is the improvement in skin perfusion pressure of the target limb 180 days after BM-MNC implantation, whereas secondary endpoints are improvements in rest pain or ulcer size. We will also investigate rates of major or minor amputation, survival, and adverse events during follow-up.

Conclusions: BM-MNC implantation is expected to be an efficacious and feasible treatment for patients with CLTI caused by TAO.

Rationale and Design of Therapeutic Angiogenesis by Cell Transplantation Using Adipose-Derived Regenerative Cells in Patients With Critical Limb Ischemia - TACT-ADRC Multicenter Trial

Background: Despite the growing knowledge regarding optimal treatments for critical limb ischemia (CLI), there are still a considerable number of patients who have to undergo major limb amputation. Intramuscular injection of autologous adipose-derived regenerative cells (ADRCs) in these patients has shown therapeutic potential in improving tissue ischemia, in both preclinical and initial pilot studies. Here, we present a clinical protocol for ADRCs use in a multicenter trial.

Methods and Results: The TACT-ADRC multicenter trial is a prospective, interventional, single-arm, open-labeled study at 8 hospitals in Japan, investigating the safety and feasibility of intramuscular injections of ADRCs and testing the hypothesis that this treatment promotes neovascularization and improves major amputation-free survival rates in patients with CLI who have no other treatment option. 40 patients with CLI will be enrolled and followed up from November 2015 to November 2020. Freshly isolated autologous ADRCs will be injected into the target ischemic limbs. Survival rate, adverse events, major limb amputation, ulcer size, 6-min walking distance, numerical rating scale, ankle–brachial pressure index, skin perfusion pressure and digital subtraction angiography will be evaluated at baseline and during 6 months’ follow-up.

Conclusions: This trial will demonstrate whether implantation of autologous ADRCs is a safe and effective method for therapeutic angiogenesis, resulting in an improvement in major amputation-free survival rates in patients with CLI.

Impact of Therapeutic Angiogenesis Using Autologous Bone Marrow-derived Mononuclear Cell Implantation in Patients with No-option Critical Limb Ischemia

Recently, the limb salvage rate of patients with critical limb ischemia (CLI) has been improved due to the development of revascularization and wound care treatment. However, many patients with CLI are refractory to standard treatments, including revascularization such as endovascular treatment or surgical bypass. Establishment of a new cell therapy is required to improve the limb salvage rate and prognosis in patients with CLI. In 1997, endothelial progenitor cells were found to be derived from the bone marrow to circulate as CD34 surface antigen positive cells in peripheral blood and to affect therapeutic angiogenesis in ischemic tissues. Later, therapeutic angiogenesis using autologous bone marrow-derived mononuclear cell (BM-MNC) implantation was performed for patients with no-option CLI in clinical practice. Several reports showed the safety and efficacy of the BM-MNC implantation in patients with CLI caused by arteriosclerosis obliterans, thromboangiitis obliterans (TAO), and collagen diseases. In particular, in patients with CLI caused by TAO, limb salvage rate was significantly improved compared with standard treatments. The BM-MNC implantation may be feasible and safe in patients with no-option CLI. Here, we review the efficacy of BM-MNC implantation in no-option CLI, with a focus on therapeutic angiogenesis.

[Factors of adverse prediction of application of spinal cord stimulation with chronic pain syndrome in patients with critical lower limb ischemia]

AIM

To study the clinical dynamics in the long-term period after spinal cord stimulation (SCS) in patients with chronic pain syndrome and critical lower limb ischemia (CLLI) and to identify factors affecting the prognosis of SCS.

MATERIAL AND METHODS

The clinical dynamics was analyzed in 48 patients with pain syndrome and CLLI 1 year after SCS. Microcirculatory blood flow (MBF) was studied in the affected foot by laser-doppler flowmetry (LDF) (Perfusion Units (PU)) and transcutaneous oximetry (TcpO₂, mmHg.) using an occlusive test before and after SCS. The factors associated with negative clinical dynamics 1 year after SCS were determined.

RESULTS

In 74% of cases, SCS contributes to the improvement of clinical status (reduction of pain syndrome, increase in motor activity, healing of ulcers). After SCS, according to LDF and TcpO₂, the authors observed an increase in MBF and tissue metabolism - from 1.3 (0.7-2.8) to 6.2 (3.8-8.7) PU and from 14.5 (7.5-22.1) to 41.1 (26.4-57.6) mmHg, respectively with normalization of the MBF reserve during the occlusion test. Negative clinical dynamics after SCS is associated with high comorbidity, TcO₂ <10 mmHg and the duration of pain.

CONCLUSION

SCS contributes to the improvement of the clinical status of patients with chronic pain syndrome and CLLI. The negative dynamics is associated with high comorbidity, TcrO₂ <10 mmHg and the duration of pain.

Long-Term Outcomes of Acute Limb Ischemia: A Retrospective Analysis of 93 Consecutive Limbs

Objective: To examine the medium- to long-term outcomes of acute limb ischemia (ALI), which are unclear at present.

Methods: We analyzed 93 consecutive limbs in 77 patients with ALI between January 2005 and December 2015 treated at our vascular center. We categorized the cases into four groups according to etiology (embolism, thrombosis, graft thrombosis, and dissection groups) to assess survival, limb salvage, and freedom from re-intervention rates.

Results: The mean age at onset was 72±15 years. The median follow-up length was 2.90 years. The Rutherford categories I, IIa, IIb, and III included 1, 38, 51, and 3 cases, respectively. Thromboembolectomy was performed in all patients in the embolism and thrombosis groups. In addition, endovascular treatment was performed in 25 (37.3%) patients, especially in the thrombosis group (81.3%). A major amputation could not be avoided in 10 patients. The 5-year limb salvage rates for categories IIa and IIb were 97.1% and 83.1%, respectively. The 5-year freedom from re-intervention rate was 89.2%. The survival rates at 1, 3, and 5 years were 87.9%, 75.2%, and 60.6%, respectively.

Conclusion: The 5-year survival rates of patients with ALI were equivalent to those with chronic limb threatening ischemia (CLTI). The intervention and long-term outcomes were distinguishable according to etiology.

Prevalence, clinical characteristics, and predictors of peripheral arterial disease in hemodialysis patients: a cross-sectional study

Background

Peripheral arterial disease (PAD) is common in patients with end-stage renal disease on hemodialysis, but is frequently underdiagnosed. The risk factors for PAD are well known within the general population, but they differ somewhat in hemodialysis patients. This study aimed to determine the prevalence of PAD and its risk factors in patients on hemodialysis.

Methods

This cross-sectional study included 156 hemodialysis patients. Comorbidities and laboratory parameters were analyzed. Following clinical examinations, the ankle-brachial index was measured in all patients. PAD was diagnosed based on the clinical findings, ankle-brachial index < 0.9, and PAD symptoms.

Results

PAD was present in 55 of 156 (35.3%; 95% CI, 27.7–42.8%) patients. The patients with PAD were significantly older (67 ± 10 years vs. 62 ± 11 years, p = 0.014), more likely to have diabetes mellitus (p = 0.022), and anemia (p = 0.042), and had significantly lower serum albumin (p = 0.005), total cholesterol (p = 0.024), and iron (p = 0.004) levels, higher glucose (p = 0.002) and C-reactive protein (p < 0.001) levels, and lower dialysis adequacies (p = 0.040) than the patients without PAD. Multivariate analysis showed higher C-reactive protein level (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.00–1.06; p = 0.030), vascular access by Hickman catheter (OR, 4.66; 95% CI, 1.03–21.0; p = 0.045), and symptoms of PAD (OR, 5.20; 95% CI, 2.60–10.4; p < 0.001) as independent factors associated with PAD in hemodialysis patients.

Conclusion

The prevalence of PAD was high among patients with end-stage renal disease on hemodialysis. Symptoms of PAD, higher C-reactive protein levels, and Hickman vascular access were independent predictors of PAD in patients on hemodialysis.

Cryopreserved Allografts for Treatment of Chronic Limb-Threatening Ischemia in Patients Without Autologous Saphenous Veins

BACKGROUND

Revascularization is the best alternative to reduce symptoms and to improve the limb salvage rate in patients with chronic limb-threatening ischemia (CLI). Alternative grafts as synthetic prostheses and allografts must be considered for patients without a suitable autologous graft. Our aim was to evaluate outcomes of cryopreserved allografts used as a vascular conduit for bypass surgery in the infrainguinal territory.

METHODS

A retrospective analysis (January 1995 to January 2014) of the Registry of vascular and valvular allografts transplant in the autonomous community of Catalonia, Spain was performed for identifying patients with CLI who required infrainguinal bypass with cryopreserved arterial allografts. Statistical analysis was performed using SPSS, ver. 20, for Mac (Chicago).

RESULTS

A total of 149 patients with CLI (mean age of 70.1 years) were analyzed. One hundred two patients (68.5%) had a grade IV lesion (Fontaine classification). In the overall follow-up, 24.8% of patients required a reintervention. Overall graft occlusion, infection, and dilation rate were 52.3%, 6%, and 5.4% respectively. Overall 30-day mortality was 0.7%. Five-year primary patency rate and limb salvage rate were 38.6% and 50.2%, respectively. Survival rate at 5 years was 54.2%. Major adverse limb event (MALE)-free rate was 21.5% at 5 years. Revascularization to a distal target vessel was an independent positive predictive risk factor for a lower limb salvage rate and lower primary patency rate. Dyslipidemia was related to a lower limb salvage rate and represents a risk factor involved in MALEs.

CONCLUSIONS

Although arterial allografts seem to represent a suboptimal alternative, some selected patients could beneficiate from them. Five-year results are disappointing, and more studies are required to know other predictive factors for better selection of patients.

[Prolonged paravertebral analgesia in therapy of chronic pain syndrome in critical lower-limb ischaemia]

Chronic pain syndrome in patients presenting with lower-limb critical ischaemia may have considerable significance in progression of the degree of limb ischaemia, and quality of life of patients appears to be largely determined by adequate analgesia. Currently, there is no 'gold standard' of therapy for chronic pain syndrome in critical lower-limb ischaemia, which makes it necessary to search for new effective and safe methods of analgesia. The purpose of this study was to evaluate efficacy and safety of paravertebral analgesia compared with epidural analgesia in therapy of chronic pain syndrome in critical lower-limb ischaemia. Our prospective randomized double-centre study included a total of 40 patients suffering from atherosclerotic-genesis critical lower-limb ischaemia and pronounced unilateral pain syndrome. The patients were randomized into two equal groups comprising 20 patients each. They were comparable by the main clinical and demographic parameters, as well as by the scope of the comprehensive treatment performed. In the study group, therapy of chronic pain syndrome was provided by the method of paravertebral analgesia, with the comparison group patients receiving epidural analgesia. Paravertebral analgesia was performed with the use of ultrasound navigation, in the prolonged mode by means of using microinfusion elastomeric pumps, epidural analgesia - according to the standard technique. The use of various methods of analgesia was accompanied by a decrease in chronic pain syndrome according to the visual analogue scale by 60% within the first 24 hours, and by 65% at 72 hours thereafter, with the differences being statistically insignificant. The use of prolonged paravertebral analgesia was accompanied by neither considerable haemodynamic reactions nor the development of the motor block, however requiring significant expenditure of a local anaesthetic. The conclusion was drawn that paravertebral analgesia in lower-limb critical ischaemia turned out to be a safe and efficient method of comprehensive therapy of chronic pain syndrome.

Distal Bypass to the Palmar Arch to Rescue Digital Ischemia Due to Peripheral Artery Disease

Digital ischemia is a serious problem in peripheral artery diseases (PAD) patients. Case 1: A 60-year-old woman with large arteriovenous fistula (AVF) complained of digital ischemia symptoms. The patient underwent dissection of AVF and distal bypass to the palmar arch with successful repair. Case 2: A 47-year-old female, diagnosed with renal failure, and scleroderma, complained of a digital gangrene. A bypass was performed from the left brachial artery to the superficial palmar arch. The digital gangrene showed a complete recovery within 2 months after surgery. Distal bypass to the palmar arch thus appears to be a useful procedure to re-establish digital circulation in PAD patients.

Review of Transmetatarsal Amputations in the Management of Peripheral Arterial Disease in an Asian Population

Objective: To evaluate outcomes after transmetatarsal amputation (TMA) in peripheral arterial disease (PAD) limb salvage in an Asian population and identify risk factors associated with TMA failure. Methodology: A retrospective review of 147 patients with PAD, who had undergone TMA between 2008 and 2014, was carried out. Univariate and multivariate analysis were used to identify predictors of TMA failure. Kaplan-Meier survival analysis was used to calculate major amputation and all-cause mortality rates. Results: The mean age was 66 years. 92% were diabetic patients and 78% had preceded angioplasty. 56% of TMAs were healed via secondary intention, 8% required subsequent split-thickness skin graft closure, 24% required further debridement while 37% had wounds, which failed to heal and required below-knee amputations (BKA). Multivariate analysis showed that diabetes is the only independent predictor of TMA failure (odds ratio (OR) 7.11, p=0.064). Patients with TMA failure were at increased risk of developing nosocomial infections (p=0.025) and faced a higher risk of 30-day re-admission rate (p=0.002). Conclusion: The success rate for PAD limb salvage TMA was 63% and diabetes was an independent predictor of TMA failure. Patients with TMA failure were at increased risks of nosocomial infections, and 30-day re-admissions; hence the risks and benefits of TMA for diabetic foot limb salvage must be individualized for each patient.

Neutrophil-to-lymphocyte ratio is effective prognostic indicator for post-amputation patients with critical limb ischemia

To confirm whether neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are indicators for the prognosis of post-amputation patients with critical limb ischemia (CLI). Methods: In this retrospective observational study a total 270 post-amputation patients with CLI were included between January 2010 and December 2014 in the First Hospital of Jilin University, Changchun, China. The neutrophil and lymphocyte counts were recorded before amputations. Neutrophil-to-lymphocyte ratio was calculated and NLR ≥8.08 was defined as elevated. Logistic regression analysis was conducted to test the prognostic value. Results: According to the statistical analysis, it was indicated that NLR ≥8.08 (odds ratio [OR]: 26.228, 95% confidence interval [CI]: 5.801-118.583, p less than 0.001), PLR ≥237.14 (OR: 3.464, 95% CI: 1.289-9.308, p=0.014) and coronary heart disease (OR: 2.739, 95% CI: 1.060-7.082, p=0.038) were the independent prognostic indicators for the patients. Conclusion: Neutrophil-to-lymphocyte ratio, PLR, and coronary heart disease are independent prognostic indicators for post-amputation patients with CLI.

The efficacy of a multidisciplinary team approach in critical limb ischemia

The aim of the present study was to clarify the characteristics of Japanese critical limb ischemia (CLI) patients and analyze the rates of real-world mortality and amputation-free survival (AFS) in all patients with Fontaine stage IV CLI who were treated with/without revascularization therapy by an intra-hospital multidisciplinary care team. All consecutive patients who presented with CLI at Showa University Fujigaoka Hospital between April 2008 and March 2014 were prospectively registered. The intra-hospital committee consisted of cardiologists, plastic surgeons, dermatologists, diabetologists, nephrologists, cardiovascular surgeons, and vascular technologists. The primary endpoint of this study was all-cause mortality and AFS during the follow-up period. The present study included 145 patients with Fontaine stage IV CLI. The mean age was 76.5 ± 10.2 years. The all-cause mortality rate during the follow-up period (15.5 ± 16.1 months) was 21.4 %. The AFS rate during the follow-up period (14.1 ± 16.4 months) was 58.6 %. A multivariate Cox proportional hazards regression analysis found that age >75 years and hemodialysis were significantly associated with all-cause mortality; and that age >75 years, Rutherford 6, and wound infection were significantly associated with AFS. A multidisciplinary approach and comprehensive care may improve the outcomes and optimize the collaborative treatment of CLI patients. However, all-cause mortality remained high in patients with Fontaine stage IV CLI and early referral to a hospital that can provide specialized treatment for CLI, before the occurrence of major tissue loss or infection, is necessary to avoid primary amputation.