Redefining the treatment of peripheral artery disease. Role of percutaneous revascularization

Multiple metabolic comorbidities and their consequences among patients with peripheral arterial disease

Older adults with peripheral arterial disease (PAD) have increased risks of major cardiovascular events and hospitalization. Metabolic comorbidities, such as hypertension, diabetes mellitus, and dyslipidemia, are common risk factors for these unfavorable health events. This study aimed to determine how multiple metabolic comorbidities affect the risk of adverse health outcomes in older adults with PAD. A retrospective cohort study was adopted using administrative claim data from the Health Insurance Review and Assessment Service Agency. The study sample included 3,122 older adults (≥ 65 years old) with at least one PAD diagnosis in an inpatient setting from 2011 to 2013 and who had at least one follow-up visit after hospitalization by 2018. The three metabolic comorbidities were defined as having at least two diagnostic claims or one prescription per year of anti-hypertensive, anti-diabetic, or anti-dyslipidemic medications for the corresponding diagnosis. The outcome variables included major adverse cardiovascular events (MACEs) and major adverse limb events (MALE). Kaplan-Meier survival curves demonstrated that PAD patients with more metabolic comorbidities had shorter MACE-free and MALE-free periods. Adjusted Cox proportional hazards analyses suggested significant additive effects of multiple metabolic comorbidities on increased risks of MACE and MALE among older adults with PAD. Lower socioeconomic status and non-metabolic comorbidities also increased the risk of MACE. Male sex, being young-old (65–74 years), and a higher proportion of inpatient claims increased the risk of MALE. The findings of this study suggest the need for a comprehensive care program for older adults with PAD and metabolic comorbidities. In addition, the healthcare utilization pattern should be considered when designing preventive care for older patients with comorbidities to manage PAD at an earlier stage.

Efficacy and safety of intramuscular administration of allogeneic adipose tissue derived and expanded mesenchymal stromal cells in diabetic patients with critical limb ischemia with no possibility of revascularization: study protocol for a randomized controlled double-blind phase II clinical trial (The NOMA Trial)

Background

Chronic lower limb ischemia develops earlier and more frequently in patients with type 2 diabetes mellitus. Diabetes remains the main cause of lower-extremity non-traumatic amputations. Current medical treatment, based on antiplatelet therapy and statins, has demonstrated deficient improvement of the disease. In recent years, research has shown that it is possible to improve tissue perfusion through therapeutic angiogenesis. Both in animal models and humans, it has been shown that cell therapy can induce therapeutic angiogenesis, making mesenchymal stromal cell-based therapy one of the most promising therapeutic alternatives. The aim of this study is to evaluate the feasibility, safety, and efficacy of cell therapy based on mesenchymal stromal cells derived from adipose tissue intramuscular administration to patients with type 2 diabetes mellitus with critical limb ischemia and without possibility of revascularization.

Methods

A multicenter, randomized double-blind, placebo-controlled trial has been designed. Ninety eligible patients will be randomly assigned at a ratio 1:1:1 to one of the following: control group (n = 30), low-cell dose treatment group (n = 30), and high-cell dose treatment group (n = 30). Treatment will be administered in a single-dose way and patients will be followed for 12 months. Primary outcome (safety) will be evaluated by measuring the rate of adverse events within the study period. Secondary outcomes (efficacy) will be measured by assessing clinical, analytical, and imaging-test parameters. Tertiary outcome (quality of life) will be evaluated with SF-12 and VascuQol-6 scales.

Discussion

Chronic lower limb ischemia has limited therapeutic options and constitutes a public health problem in both developed and underdeveloped countries. Given that the current treatment is not established in daily clinical practice, it is essential to provide evidence-based data that allow taking a step forward in its clinical development. Also, the multidisciplinary coordination exercise needed to develop this clinical trial protocol will undoubtfully be useful to conduct academic clinical trials in the field of cell therapy in the near future.

Trial registration

ClinicalTrials.govNCT04466007. Registered on January 07, 2020. All items from the World Health Organization Trial Registration Data Set are included within the body of the protocol.

Effect of Chronic Kidney Disease on Mortality in Patients Who Underwent Lower Extremity Peripheral Vascular Intervention

It is known that chronic kidney disease (CKD) is associated with increased postoperative morbidity and mortality in patients with peripheral artery disease who underwent lower extremity surgical revascularization; however, outcomes after peripheral vascular intervention (PVI) are less well established. This study sought to determine the impact of CKD on adverse outcomes in patients with peripheral artery disease who underwent PVI. Using data from the Veteran Affairs Clinical Assessment, Reporting, and Tracking System Program, we identified a cohort of 755 patients who underwent lower extremity PVI from June 2005 to August 2010 at 33 sites. The outcomes of interest were mortality, progression to dialysis, myocardial infarction, limb amputation, and stroke. Kaplan-Meier survival analysis and Cox proportional hazard frailty models assessed the association between CKD and adverse outcomes. Of the patients who underwent lower extremity PVI, 201 patients (27%) had CKD. The presence of CKD was associated with decreased survival (5-year survival probability of CKD compared with non-CKD: 49.9% [41.6% to 59.9%] vs 80.1% [76.2% to 84.1]), which persisted after risk adjustment (HR 1.57; 95% confidence interval 1.13 to 2.19). In addition, there was a significant association between CKD and progression to dialysis (HR 6.62; 95% confidence interval 2.25 to 19.43). In contrast, there was no association between CKD and re-hospitalization for myocardial infarction, limb amputation, or stroke. In conclusion, CKD is present in 1 of 4 patients who underwent PVI and is associated with increased risk of mortality and progression to dialysis.

Covered vs Uncovered Stents for Aortoiliac and Femoropopliteal Arterial Disease

Purpose: To evaluate outcomes of covered vs bare metal stents for the treatment of lower limb peripheral artery disease. Methods: A search of electronic databases was performed to identify all studies comparing outcomes of covered vs bare metal stents for treatment of aortoiliac and femoropopliteal arterial disease. The Cochrane tool and the Newcastle-Ottawa scale were used to assess the risk of bias in randomized controlled trials (RCTs) and observational studies, respectively. Fixed or random effects models were applied to analyze pooled outcome data. The results for dichotomous outcome variables are presented as the odds ratio (OR) and 95% confidence interval (CI); intergroup comparisons of continuous clinical variables are reported as the mean difference (MD) and 95% CI. Results: Two RCTs and 4 retrospective cohort studies, enrolling 744 patients (mean age 67 years; 477 men) and 918 diseased arteries, were identified. For aortoiliac disease, treatment with a covered stent showed no significant improvement in primary patency (OR 2.10, 95% CI 0.48 to 9.11, p=0.32), but it was associated with higher ankle-brachial index (ABI) (MD 0.08, 95% CI 0.07 to 0.09, p<0.001) and a lower reintervention rate (OR 0.19, 95% CI 0.09 to 0.42, p<0.001). For femoropopliteal disease, use of covered stents was associated with increased primary patency (OR 1.84, 95% CI 1.11 to 3.06, p=0.02), higher ABI (MD 0.08, 95% CI 0.00 to 0.16, p=0.04), and a lower reintervention rate (OR 0.51, 95% CI 0.30 to 0.87, p=0.01). No significant differences in technical success, complications, limb salvage, or survival were identified between the groups in either segment. Conclusion: Theoretically, the use of covered stents may increase the patency rate due to decreased restenosis after stent placement. This analysis found that the primary patency was improved with the use of a covered stent in femoropopliteal lesions but not in aortoiliac disease. Improved outcomes were seen with covered stents compared with bare metal stents as indicated by a lower need for reintervention and an improved ABI. It remains to be investigated whether such beneficial effects can be translated into improved clinical outcomes, such as limb salvage and amputation-free survival. Long-term results of the comparative efficacy of covered stents over bare metal stents are not currently available.

Extracellular Matrix Hydrogel Promotes Tissue Remodeling, Arteriogenesis, and Perfusion in a Rat Hindlimb Ischemia Model

Although surgical and endovascular revascularization can be performed in peripheral arterial disease (PAD), 40% of patients with critical limb ischemia do not have a revascularization option. This study examines the efficacy and mechanisms of action of acellular extracellular matrix-based hydrogels as a potential novel therapy for treating PAD. We tested the efficacy of using a tissue-specific injectable hydrogel derived from decellularized porcine skeletal muscle (SKM) and compared this to a new human umbilical cord-derived matrix (hUC) hydrogel, which could have greater potential for tissue regeneration because of the younger age of the tissue source. In a rodent hindlimb ischemia model, both hydrogels were injected 1-week post-surgery and perfusion was regularly monitored with laser speckle contrast analysis to 35 days post-injection. There were significant improvements in hindlimb tissue perfusion and perfusion kinetics with both biomaterials. Histologic analysis indicated that the injected hydrogels were biocompatible, and resulted in arteriogenesis, rather than angiogenesis, as well as improved recruitment of skeletal muscle progenitors. Skeletal muscle fiber morphology analysis indicated that the muscle treated with the tissue-specific SKM hydrogel more closely matched healthy tissue morphology. Whole transcriptome analysis indicated that the SKM hydrogel caused a shift in the inflammatory response, decreased cell death, and increased blood vessel and muscle development. These results show the efficacy of an injectable ECM hydrogel alone as a potential therapy for treating patients with PAD. Our results indicate that the SKM hydrogel improved functional outcomes through stimulation of arteriogenesis and muscle progenitor cell recruitment.

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Although surgical and endovascular revascularization can be performed in patients with peripheral arterial disease (PAD), 40% of patients with critical limb ischemia do not have a revascularization option.

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The efficacy of an injectable tissue-specific skeletal muscle extracellular matrix (ECM) hydrogel and a human umbilical cord-derived ECM hydrogel were examined in a rodent hindlimb ischemia model.

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Although both biomaterials increased tissue perfusion 35 days post-injection, likely through arteriogenesis, the skeletal muscle ECM hydrogel more closely matched healthy tissue morphology.

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Transcriptomic analysis indicates the skeletal muscle ECM hydrogel shifted the inflammatory response, decreased necrosis/apoptosis, and increased blood vessel and muscle development.

The BEST-CLI trial: a multidisciplinary effort to assess which therapy is best for patients with critical limb ischemia

Critical limb ischemia (CLI) is the most severe form of peripheral arterial disease and is associated with a significant risk of limb loss. It is currently treated with limb revascularization by a variety of specialists. Although both open vascular bypass and endovascular therapy are offered to patients with infrainguinal peripheral arterial disease and CLI, significant disagreement exists as to which therapy works best in candidates for both types of intervention. Persistent clinical equipoise in combination with a paucity of comparative effectiveness data to guide treatment of CLI has led to a multidisciplinary effort to organize the Best Endovascular versus Best Surgical Therapy in patients with CLI (BEST-CLI) trial. The BEST-CLI trial is a pragmatic, multicenter, open label, randomized trial that compares best endovascular therapy with best open surgical treatment in patients eligible for both treatments. This trial is highly innovative in both its design and its collaborative nature. BEST-CLI aims to provide urgently needed clinical guidance for CLI management by using (1) a pragmatic design comparing the effectiveness of established techniques while allowing for the introduction of newer therapies as they become available; (2) a novel primary end point that includes limb amputation rates, repeat intervention, and mortality; (3) a multidisciplinary structure that fosters cooperation among interventional cardiologists, interventional radiologists, vascular surgeons, and vascular medicine specialists; and (4) novel techniques to evaluate the cost-effectiveness and quality-of-life outcomes of the 2 treatment strategies being tested.

Vibrational angioplasty in recanalization of chronic femoropopliteal arterial occlusions: single center experience

PURPOSE

This prospective study aims to present the overall success rate, safety and long-term outcome of vibrational angioplasty technique, in the treatment of chronic total femoropopliteal occlusions in our institute.

METHODS

Between October 2000 and December 2008, patients with chronic total femoropoliteal arterial occlusions, treated with vibrational angioplasty during the same session after a failed attempt with conventional recanalization technique, were included. Patient's follow up included serial ankle-brachial index measurements and arterial duplex ultrasound examinations at 1, 3, 6, 12, 24, 36 and 48 months.

RESULTS

Twenty-seven patients (16 males and 11 females) and twenty-eight lesions were included in our study. Twenty-five lesions (89.3%) were successfully recanalized. Pain relief was noticed in twenty-one cases. From ten lesions with tissue loss (ulcer or gangrene) in successfully recanalized occlusions, six healed without major, or minor amputation. One non-healing amputation stump was healed after recanalization, without further complications. Four limbs underwent amputation (one minor and three major) despite successful recanalization, however all had an excellent healing of the amputation stump without further complications. The Kaplan-Meier test demonstrated 90%, 85% and 70% amputation-free survival rate at 12, 24 and 36 months, respectively. No major or minor complications were encountered.

CONCLUSIONS

Vibrational angioplasty is a safe, effective and durable endovascular technique for the treatment of chronic total occlusions in patients with limb ischemia that would be difficult to recanalize using conventional intraluminal techniques.

Endovascular stents: a review of their use in peripheral arterial disease

Technological advances in the past decade have shifted revascularization strategies from traditional open surgical approaches toward lower-morbidity percutaneous endovascular treatments for patients with lower extremity peripheral arterial disease (PAD). The continuing advances in stent design, more than any other advances, have fueled the growth of catheter-based procedures by improving the safety, durability, and predictability of percutaneous revascularization. Although the 2007 TransAtlantic Inter-Society Consensus (TASC) guidelines recommend endovascular therapy for type A and B aortoiliac and femoropopliteal lesions, recent developments in stent technology and increased experience of interventionists have suggested that a strategy of endovascular therapy first is appropriate in experienced hands for TASC type D lesions. The role of endovascular interventions is also expanding in the treatment of limb-threatening ischemia.

Effect of normalization of fasting glucose by intensified insulin therapy and influence of eNOS polymorphisms on the incidence of restenosis after peripheral angioplasty in patients with type 2 diabetes: a randomized, open-label clinical trial

Primary objective was to evaluate whether an intensified insulin therapy (IIT) incorporating the target of normal fasting glucose and HbA1c levels could halve the incidence of restenosis/amputation/SCA/death at 6 months after peripheral angioplasty compared with standard care (SC) in patients with type 2 diabetes (DMT2) affected by critical limb ischemia (CLI). Forty-six consecutive patients with DMT2 and CLI were randomly assigned to a parallel, open-label study with IIT (basal-bolus glulisine + glargine administrations) or SC (glargine administration + oral antidiabetic drugs). A SNP of eNOS (rs753482-A>C) and circulating CD34(+) and CD34(+)KDR(+) progenitor cells were determined. At the end of the study, although HbA1c levels were lower in IIT than in SC (6.9 ± 1.3 % vs. 7.6 ± 1.2 %, p < 0.05), IIT did not reduce the cumulative incidence of restenosis/amputation/SCA/death (52 and 65 %, respectively, odd ratio 0.59; CI 95 %: 0.21-1.62, p = 0.59). rs753482AC+CC as compared with rs753482AA increased the cumulative incidence of restenosis/amputation/SCA/death (79 and 42 %; odd ratio 5.3; CI 95 %: 1.41-19.5, p < 0.02). Baseline CD34(+)KDR(+) were higher in rs753482AA (166.2 ± 154.0 × 10(6) events) than in rs753482AC+CC (63.1 ± 26.9 × 10(6) events, p < 0.01). At the end of the study, the highest circulating CD34(+)KDR(+) were found in IIT rs753482AA (246.9 ± 194.0 × 10(6) events) while the lowest levels were found in SC rs753482AC+CC (70.9 ± 45.0 × 10(6) events). IIT did not decrease the cumulative incidence of restenosis/amputation/SCA/death in DMT2 and CLI patients. These patients correspond to a class of fragile subjects at high risk of cardiovascular events, and new predictors of restenosis should be contemplated, such as of eNOS polymorphism, (rs753482-A>C SNP) and circulating endothelial progenitor cells.

Endovascular intervention in Taiwanese patients with critical limb ischemia: patient outcomes in 333 consecutive limb procedures with a 3-year follow-up

BACKGROUND/PURPOSE

Midterm outcomes of endovascular intervention (EVI) for critical limb ischemia (CLI) have not been previously reported in Taiwan. This study assessed the safety, feasibility, and patient-oriented outcomes for CLI patients after EVI.

METHODS

From June 2005 to December 2011, 270 patients underwent EVI for CLI of 333 limbs. Primary patency (PP), assisted primary patency (AP), limb salvage, sustained clinical success (SCS), secondary SCS (SSCS), and survival were assessed using Kaplan-Meier analysis.

RESULTS

The procedural success rate was 89%, and the periprocedural mortality and major complication rates within 30 days were 0.6% and 6.9%, respectively. During the mean follow-up time of 27 ± 20 months (1-77), 64 patients died and 25 legs required major amputation. Eighty-one percent of the patients with tissue loss had wound healing at 6 months and 75% of the patients were ambulatory, with or without assisting devices, at 1 year. The overall survival and limb salvage rates at 3 years were 70% and 90%, respectively. The PP and AP at 1 and 3 years were 58% and 37% and 79% and 61%, respectively. The SCS and SSCS were 65% and 46% and 80% and 64% at 1 and 3 years, respectively.

CONCLUSION

In Taiwan, EVI was a safe and feasible procedure for CLI patients, with a high procedural success rate and lower complication rate. Sustained limb salvage and clinical success can be afforded with an active surveillance program and prompt intervention during midterm follow-up.

Limb revascularization feasibility in diabetic patients with critical limb ischemia: results from a cohort of 344 consecutive unselected diabetic patients evaluated in 2009

AIMS

To evaluate the feasibility of peripheral revascularization by angioplasty (PTA) or bypass grafting (BPG) in diabetic patients with critical limb ischemia (CLI).

METHODS

All diabetic patients referred to our Diabetic Foot Centre for foot lesion or rest pain were assessed for the presence of CLI as assessed by the TASC criteria. All patients underwent angiography that was evaluated jointly by an interventional radiologist, a vascular surgeon and a diabetologist of the diabetic foot care team.

RESULTS

During 2009, 344 diabetics were admitted because of CLI in a total of 360 limbs. PTA was performed in 308 (85.6%) limbs, and BPG was performed in 40 (11.1%) limbs in which PTA was not feasible. Revascularization could not be carried out in 12 (3.3%) limbs due to the lack of target vessel (9 limbs) or high surgical risk (3 limbs). According to the judgement of the vascular surgeon, BPG was anatomically feasible in 180 (58.4%) of the 308 limbs that underwent PTA. Therefore, considering also the 40 limbs that underwent BPG, surgical revascularization was judged anatomically possible in a total of 220 (61.1%) limbs. At 30 days, 19 (5.3%) above-the-ankle amputations were performed: 8 (66.7%) amputations were performed in the 12 non-revascularized limbs, 8 (2.6%) amputations were performed in the 308 limbs treated with PTA and 3 (7.5%) amputations were performed in the 40 limbs treated with BPG.

CONCLUSIONS

Revascularization by PTA is highly feasible in diabetics with CLI. The feasibility of revascularization by BPG is lower but nonetheless consistent. In centres where both revascularization procedures are available, it is possible to revascularize more than 96% of diabetics with CLI.

Alternative techniques for treatment of complex below-the knee arterial occlusions in diabetic patients with critical limb ischemia

PURPOSE

The purpose of this study was to describe alternative endovascular (EV) techniques and assess their feasibility and efficacy in minimizing failure rates in limb salvage for the treatment of complex below-the knee (BTK) occlusions that could not be crossed with a conventional antegrade access.

MATERIALS AND METHODS

Between December 2007 and November 2010, 1,035 patients (557 male) underwent EV treatment for critical limb ischemia in our institution. In 124 (12% [83 male], mean age 68.2 ± 0.5 years) patients, transfemoral antegrade revascularization attempt failed, and an alternative approach was used. Follow-up was performed at 1 and 6 months. Results were compared with 56 patients treated between November 2002 and November 2007, in whom conventional technique was unsuccessful and unconventional techniques were not adopted.

RESULTS

Technical success was achieved in 119 (96%) patients. The limb-salvage rates were 96.8% and 83% at 1- and 6-month follow-up, respectively. Sixteen (12.9%) and 33 (26.6%) patients underwent reintervention at 1- and 6-month follow-up, respectively. Transcutaneous oxygen tension increased at 1 month (44.7 ± 1.1 vs. 15.7 ± 0.8 mmHg; p < 0.001) and remained stable at follow-up. Twenty (16.1%) patients required major amputation. Thirteen (10.4%) patients died during follow-up. In our previous experience, percutaneous transluminal angioplasty failure, amputation, and death rates were 10.9, 39.2, and 23.2%, respectively. Alternative techniques allowed a significant decrease of major amputation and death rates (p = 0.0001 and p = 0.02, respectively).

CONCLUSION

The use of alternative techniques seems feasible in case of a failed antegrade BTK revascularization attempt and could minimize failure rates in the treatment of complex occlusions while providing satisfying clinical success rates at 6 months.

Wound healing gene therapy: cartilage regeneration induced by vascular endothelial growth factor plasmid

AIMS

The identification of growth factors and cytokines with angiogenic activity has enabled new therapeutic treatments for a variety of diseases; this concept is called therapeutic angiogenesis. The vascular endothelial growth factor (VEGF) is the most critical regulator of vascular formation. In the present study, we were interested in the therapeutic angiogenesis effect using plasmid transfer of human complementary DNA VEGF(165) (phVEGF(165)) in experimental skin and cartilage trauma.

METHODS

Ten BALB/c mice were used for cartilage injury model. At 6 weeks of age, all mice were ear-punched, resulting in 2-mm-diameter puncture through the center of both pinnae. Each mouse got phVEGF(165) injection into the first ear and vector without insert or saline injection into the second one. The healing process was followed. The hollow diameter was measured on days 0, 14, and 42. Histological sections of experimental and control pinnae were taken from days 1, 3, 5, 7, 9, 11, 13, 15, 20, and 30 after experimental injury for hematoxylin and eosin and periodic acid Schiff staining and for human VEGF immunocytochemistry. The expression of human VEGF was also checked by real-time polymerase chain reaction in formalin-fixed, paraffin-embedded tissue sections.

KEY FINDINGS

In BALB/c mouse strain, a significant angiogenesis promotion and cartilage repair were observed after phVEGF(165) injection into the punched ear area.

SIGNIFICANCE

We suggest that administering phVEGF(165) leads to faster cartilage regeneration even if not only on the angiogenic basis.

Tissue repair driven by two different mechanisms of growth factor plasmids VEGF and NGF in mice auricular cartilage: regeneration mediated by administering growth factor plasmids

The focus of this study was to compare the role of nerve growth factor (NGF) and vascular endothelial growth factor (VEGF) in the regeneration of experimental skin and cartilage trauma. The role of VEGF in this process is known since decade; the NGF participation on this process has been first discussed within the spinal cord injury repair. We hypothesized that both VEGF and NGF induce angiogenesis and take part on the repair process. The angiogenesis response and the cartilage regeneration after phVEGF(165) plasmid and rat pcNGF plasmid administration were investigated using BALB/c mice. PhVEGF(165) and pcNFG were injected into the right mice ear and plain vector injection into the left ear the day before trauma. The next day, all mice were ear-punched, resulting in 2-mm diameter puncture through the center of both pinnae. In BALB/c mouse strain, a significantly faster cartilage repair was observed after phVEGF(165) and pcNGF injection into punched ear area in comparison to the control group. It has been shown that the healing process is after VEGF and NGF injection driven differentially. In case of VEGF is the cartilage wound repaired by induction of new chondrocytes differentiation. In the case of NGF, the regeneration is supported by immature leukocytes attracted into the punched area. The leukocytes induct angiogenesis so far indirectly by inflammation. The NGF-induced inflammation environment may be a part of mosaic creating the complete picture of regeneration.

Long-term prognosis of diabetic patients with critical limb ischemia: a population-based cohort study

OBJECTIVE

To evaluate the long-term prognosis of critical limb ischemia (CLI) in diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 564 consecutive diabetic patients were hospitalized for CLI from January 1999 to December 2003; 554 were followed until December 2007.

RESULTS

The mean follow-up was 5.93 +/- 1.28 years. Peripheral angioplasty (PTA) was performed in 420 (74.5%) and bypass graft (BPG) in 117 (20.6%) patients. Neither PTA nor BPG were possible in 27 (4.9%) patients. Major amputations were performed in 74 (13.4%) patients: 34 (8.2%) in PTA, 24 (21.1%) in BPG, and 16 (59.2%) in a group that received no revascularization. Restenosis occurred in 94 patients, bypass failures in 36 patients, and recurrent ulcers in 71 patients. CLI was observed in the contralateral limb of 225 (39.9%) patients; of these, 15 (6.7%) required major amputations (rate in contralateral compared with initial limb, P = 0.007). At total of 276 (49.82%) patients died. The Cox model showed significant hazard ratios (HRs) for mortality with age (1.05 for 1 year [95% CI 1.03-1.07]), unfeasible revascularization (3.06 [1.40-6.70]), dialysis (3.00 [1.63-5.53]), cardiac disease history (1.37 [1.05-1.79]), and impaired ejection fraction (1.08 for 1% point [1.05-1.09]).

CONCLUSIONS

Diabetic patients with CLI have high risks of amputation and death. In a dedicated diabetic foot center, the major amputation, ulcer recurrence, and major contralateral limb amputation rates were low. Coronary artery disease (CAD) is the leading cause of death, and in patients with CAD history the impaired ejection fraction is the major independent prognostic factor.

Tc-99m-MIBI scintigraphy in evaluating the effect of hepatocyte growth factor gene therapy for peripheral arteriosclerosis obliterans

We report an 81-year-old man with arteriosclerosis obliterans with sharp rest pain of the left lower leg below the knee that was resistant to conventional drug therapy. Gene therapy using hepatocyte growth factor (HGF) was performed, following which the symptoms remarkably improved. Magnetic resonance (MR) angiography did not detect any development of collateral vessels following gene therapy; however, technetium-99m-methoxyisobutylisonitrile (Tc-99m)-MIBI scintigraphy revealed the development of micro-circulation in the lower leg following HGF gene therapy. This is the first report on the usefulness of Tc-99m-MIBI scintigraphy to evaluate the effectiveness of HGF gene therapy for peripheral arteriosclerosis obliterans.

Drug eluting stents for below the knee lesions in patients with critical limb ischemia : long-term follow-up

OBJECTIVES

The purpose of this study was to assess the long-term limb preservation and/or healing of ulcers in patients with critical limb ischemia (CLI) and severe infrapopliteal atherosclerotic disease treated with drug eluting stents (DES).

BACKGROUND

Percutaneous revascularization has become an effective treatment for CLI in patients with infrapopliteal atherosclerotic disease. Recent reports using DES in patients with CLI have documented excellent short-term infrapopliteal vessel patency. Higher primary patency rates in infrapopliteal vessels treated with DES could translate into better long-term clinical outcomes and improved limb salvage rates.

METHODS

Twenty-four consecutive patients with CLI (defined as rest pain, nonhealing ulcers, or gangrene) because of severe infrapopliteal disease were treated with DES from August 2004 to June 2006.

RESULTS

Procedural success was achieved in 96% (27/28) of targeted lesions. There were no procedure-related deaths, acute vessel thrombosis events, or need for urgent surgical intervention. There was one case of distal embolization. Clinical follow up, ranging 8-34 months, is available for 100% of patients of which 83% (20/24) achieved limb preservation and healing. Angiographic and/or sonographic follow up, ranging 6-34 months, is available in 79% (19/24) of patients of which 95% (18/19) had patent target vessels.

CONCLUSIONS

DES is a safe and effective long-term option for CLI due to severe infrapopliteal arterial disease. Long-term vascular patency led to a high rate of limb preservation and low amputation rate. A multicenter trial should further elucidate the role of DES in the treatment of CLI.

Stenting for superficial femoral artery atherosclerotic occlusion: long-term follow-up results

Recent advances in interventional devices and technology have greatly improved the results of percutaneous transluminal angioplasty (PTA), and it is now being widely used. However, it is important to obtain information regarding its results and its long-term patency. We examined the primary success rates and long-term patency in 29 limbs out of 27 patients with superficial femoral artery (SFA) occlusion who underwent PTA with self-expandable stents. Among the 29 lesions, 19 were long occlusions (>10 cm) and 10 were short (<10 cm). Overall primary success was achieved in 26 of the 29 limbs (90%). There were three unsuccessful cases in which the patients were on dialysis and had hard calcification in the arterial walls. After 3 years, primary patency, primary-assisted patency, and secondary-assisted patency were 81%, 86%, and 96%, respectively. In the case of short occlusions (<10 cm), the 3-year patency was 100%. Both the primary success rate and the long-term patency were considerably better than expected. Our results with self-expanding stents were superior to previously reported results and were not inferior to those of surgical bypass. Therefore, PTA may be considered as a good first option for the treatment of SFA occlusions.

Cell therapy for diabetes mellitus: an opportunity for stem cells?

Diabetes is a chronic disease characterized by a deficit in beta cell mass and a failure of glucose homeostasis. Both circumstances result in a variety of severe complications and an overall shortened life expectancy. Thus, diabetes represents an attractive candidate for cell therapy. Reversal of diabetes can be achieved through pancreas and islet transplantation, but shortage of donor organs has prompted an intensive search for alternative sources of beta cells. This achievement has stimulated the search for appropriate stem cell sources. Both embryonic and adult stem cells have been used to generate surrogate beta cells or otherwise restore beta cell functioning. In this regard, several studies have reported the generation of insulin-secreting cells from embryonic and adult stem cells that normalized blood glucose values when transplanted into diabetic animal models. Due to beta cell complexity, insulin-producing cells generated from stem cells do not possess all beta cell attributes. This indicates the need for further development of methods for differentiation and selection of completely functional beta cells. While these problems are overcome, diabetic patients may benefit from therapeutic strategies based on autologous stem cell therapies addressing late diabetic complications. In this article, we discuss the recent progress in the generation of insulin-producing cells from embryonic and adult stem cells, together with the challenges for the clinical use of diabetes stem cell therapy.

Enhanced angiogenesis by gelatin hydrogels incorporating basic fibroblast growth factor in rabbit model of hind limb ischemia

Recently we have developed new sustained release system of basic fibroblast growth factor (bFGF) using gelatin hydrogel as a carrier. Using this system, we examined the effect of topical sustained release of bFGF on angiogenesis and tissue blood perfusion in a rabbit model of hind limb ischemia. Thirty-two rabbits underwent excision of right femoral artery under general anesthesia. Two weeks later the rabbits were randomized into four groups (n = 8 each): no treatment, intramuscular injection of gelatin hydrogel alone, and intramuscular injection of gelatin hydrogel incorporating 30 microg and 100 microg of bFGF. Four weeks after each treatment, selective angiography, tissue blood flowmetry using laser Doppler perfusion imaging, and histological examination of thigh muscle were performed. In groups treated with bFGF incorporating gelatin hydrogel, tissue blood flow, number of arterioles, and vascular density were significantly increased in a dose-dependent manner 4 weeks after the treatment. Serum concentrations of bFGF and vascular endothelial growth factor were not elevated 4 weeks after the treatment. In conclusion, sustained release of bFGF using gelatin hydrogel augmented angiogenesis and improved tissue blood flow after excision of the femoral artery.

Percutaneous transluminal angioplasty of the popliteal artery without the use of stents: A review of 116 consecutive procedures

PURPOSE

To evaluate the safety and efficacy of percutaneous transluminal angioplasty (PTA), without the use of stents, for the treatment of popliteal artery stenosis.

METHODS

From March 1997 to December 2003, 116 consecutive PTAs of the popliteal artery were performed in 98 patients. All patients underwent preoperative and postoperative colour duplex scans and preoperative angiography. In all cases, the superficial femoral artery was patent and without significant stenosis. Follow-up patency was assessed by clinical examination and colour duplex scanning in all patients.

RESULTS

There was no perioperative mortality. Primary patency after two years was 86% for intermittent claudication (IC) patients and 54% for critical limb ischemia (CLI) patients. Secondary patency rates were 98% for IC patients versus 92% for CLI patients after one year, 94% for IC patients versus 83% for CLI patients after two years and 69% for IC patients versus 7% for CLI patients after five years (P<0.001).

CONCLUSION

Popliteal artery PTA is safe and efficient, especially in IC patients with single lesions.

Therapeutic angiogenesis by ex vivo expanded erythroid progenitor cells

Recent reports have demonstrated that erythroid progenitor cells contain and secrete various angiogenic cytokines. Here, the impact of erythroid colony-forming cell (ECFC) implantation on therapeutic angiogenesis was investigated in murine models of hindlimb ischemia. During the in vitro differentiation, vascular endothelial growth factor (VEGF) secretion by ECFCs was observed from day 3 (burst-forming unit erythroid cells) to day 10 (erythroblasts). ECFCs from day 5 to day 7 (colony-forming unit erythroid cells) showed the highest VEGF productivity, and day 6 ECFCs were used for the experiments. ECFCs contained larger amounts of VEGF and fibroblast growth factor-2 (FGF-2) than peripheral blood mononuclear cells (PBMNCs). In tubule formation assays with human umbilical vein endothelial cells, ECFCs stimulated 1.5-fold more capillary growth than PBMNCs, and this effect was suppressed by antibodies against VEGF and FGF-2. Using an immunodeficient hindlimb ischemia model and laser-Doppler imaging, we evaluated the limb salvage rate and blood perfusion after intramuscular implantation of ECFCs. ECFC implantation increased both the salvage rate (38% vs. 0%, P < 0.05) and the blood perfusion (82.8% vs. 65.6%, P < 0.01). In addition, ECFCs implantation also significantly increased capillaries with recruitment of vascular smooth muscle cells and the capillary density was 1.6-fold higher than in the control group. Continuous production of human VEGF from ECFCs in the skeletal muscle was confirmed at least 7 days after the implantation. Implantation of ECFCs promoted angiogenesis in ischemic limbs by supplying angiogenic cytokines (VEGF and FGF-2), suggesting a possible novel strategy for therapeutic angiogenesis.

Early and five-year amputation and survival rate of diabetic patients with critical limb ischemia: data of a cohort study of 564 patients

OBJECTIVE

To evaluate the early and late major amputation and survival rates and related risk factors in diabetic patients with critical limb ischemia (CLI).

DESIGN

Retrospective study.

METHODS

Revascularization feasibility, major amputation, survival rate and related risk factors were recorded in 564 diabetic patients consecutively hospitalized for CLI from 1999 to 2003 and followed until June 2005.

RESULTS

Peripheral angioplasty (PTA) was carried out in 420 (74.5%), bypass graft (BPG) in 117 (20.7%) patients. In 27 (4.8%) patients both PTA and BPG were not possible. Twenty-three above-the-ankle amputations (4.1%) were performed at 30 days: 6 in PTA patients, 3 in BPG patients, 14 in non revascularized patients. In the follow-up of 558 patients (98.9%), 62 repeated PTAs and 9 new BPGs, 32 new major amputations (16 in PTA patients, 14 in BPG patients and 2 in non-revascularized patients) were performed. Major amputation was associated with absence of revascularization (OR 35.9, p < 0.001, CI 12.9-99.7), occlusion of each of the three crural arteries (OR 8.20, p = 0.022, CI 1.35-49.6), wound infection (OR 2.1, p = 0.004 CI 1.3-3.6), dialysis (OR 4.7, p = 0.001 CI 1.9-11.7) increase in TcPO2 after revascularization (OR 0.80, p < 0.001 CI 0.74-0.87). One hundred seventy three patients died during follow-up and this was associated with age (HR 1.05, p < 0.001 CI 1.03-1.07), history of cardiac disease (HR 2.16, p < 0.001 CI 1.53-3.06), dialysis (HR 3.52, p < 0.001 CI 2.08-5.97), absence of revascularization (HR 1.68, p < 0.001, CI 1.29-2.19) and impaired ejection fraction (HR 1.08, p < 0.001, CI 1.05-1.09).

CONCLUSIONS

In diabetic patients with CLI the revascularization is feasible in most cases and allows a low rate of early major amputation. This rate is higher in the follow-up period. Major amputation is very high in patients where revascularization is not feasible while the high mortality rate is due to the serious comorbidities observed in these patients.

Gene therapy of the ischemic lower limb--Therapeutic angiogenesis

The limitations of surgical revascularisation and pharmacological treatment in peripheral arterial occlusive disease (PAOD) are well recognized. Therapeutic options for critical leg ischemia are consequently limited to percutaneous transluminal angioplasty (PTA) or surgical revascularisation. Unfortunately, many patients with critical leg ischemia are poor candidates for either procedure. Therapeutic angiogenesis is a novel promising tool to treat these patients. Experimental and clinical and trials of gene transfer for therapeutic angiogenesis have already shown some clinical efficacy. This review is focused on gene transfer techniques in preclinical and clinical therapeutic angiogenesis, angiogenic growth factors, vectors, delivery methods and routes. The results of clinical and experimental studies, safety and side effects of gene therapy, and the perspectives of future research are also discussed.

Human-grade purified collagenase for the treatment of experimental arterial chronic total occlusion

PURPOSE

Chronic total occlusions (CTO) remain a major limitation of percutaneous interventions. Procedural failure is usually due to the inability to cross the lesion with a guide wire. We have previously shown that local administration of a laboratory-grade collagenase followed by a 72-h waiting period may facilitate guide-wire crossing. The aim of the present study was to evaluate the efficacy and toxicity of a human-grade purified collagenase, suitable for clinical use, in facilitating guide-wire crossing in a rabbit model of femoral artery CTO.

METHODS AND RESULTS

A chronic total arterial occlusion was constructed in femoral arteries of New Zealand white rabbits. The local administration of purified collagenase solution (150 microg) via an over-the-wire balloon system was performed in 10 CTO. Guide-wire crossing was attempted after 24 h and was successful in all cases. Different doses (50-500 microg) were administered to an additional 17 rabbits to assess collagenase effects. Local subcutaneous bruising was observed at higher doses. Histological evaluation showed no damage to the arterial wall structure. Arterial extracts from collagenase-treated arteries showed increased MMP-2 and MMP-9 activities and higher levels of local MMP-1 and degraded collagen.

CONCLUSIONS

Local administration of a human-grade purified collagenase degrades collagen in CTO and is highly effective for the facilitation of guide-wire crossing in CTO.

Medical treatment of renal artery stenosis: is it effective and appropriate?

Recent advances in endovascular technology have radically changed the options available for the clinical management of the patient with renovascular disease. These treatment options have fueled an ongoing debate concerning the appropriateness of interventional endovascular therapy for the stenotic renal artery versus conservative medical management. This review examines a typical clinical case scenario and analyzes relevant published literature and the recent guidelines from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) highlighting the significant shortcomings of evidence-based data when it comes to the management of this complex patient population. Early diagnosis provides the best opportunity for appropriate utilization of therapeutic options and rational timing of deployment of interventional techniques. Recommendations for conservative medical management are made based on the review of the medical management arms of the published interventional series. In addition, suggestions are made for practical modifications to the JNC 7 hypertension management protocol to better address the challenging diagnostic and management issues raised by the renovascular patient.

Metabolic adaptations to repeated periods of contraction with reduced blood flow in canine skeletal muscle

Background

Patients suffering from Intermittent Claudication (IC) experience repeated periods of muscle contraction with low blood flow, throughout the day and this may contribute to the hypothesised skeletal muscle abnormalities. However, no study has evaluated the consequences of intermittent contraction with low blood flow on skeletal muscle tissue. Our aim was to generate this basic physiological data, determining the 'normal' response of healthy skeletal muscle tissue. We specifically proposed that the metabolic responses to contraction would be modified under such circumstances, revealing endogenous strategies engaged to protect the muscle adenine nucleotide pool. Utilizing a canine gracilis model (n = 9), the muscle was stimulated to contract (5 Hz) for three 10 min periods (separated by 10 min rest) under low blood flow conditions (80% reduced), followed by 1 hr recovery and then a fourth period of 10 min stimulation. Muscle biopsies were obtained prior to and following the first and fourth contraction periods. Direct arterio-venous sampling allowed for the calculation of muscle metabolite efflux and oxygen consumption.

Results

During the first period of contraction, [ATP] was reduced by ~30%. During this period there was also a 10 fold increase in muscle lactate concentration and a substantial increase in muscle lactate and ammonia efflux. Subsequently, lactate efflux was similar during the first three periods, while ammonia efflux was reduced by the third period. Following 1 hr recovery, muscle lactate and phosphocreatine concentrations had returned to resting values, while muscle [ATP] remained 20% lower. During the fourth contraction period no ammonia efflux or change in muscle ATP content occured. Despite such contrasting metabolic responses, muscle tension and oxygen consumption were identical during all contraction periods from 3 to 10 min.

Conclusion

repeated periods of muscle contraction, with low blood flow, results in cessation of muscle ammonia production which is suggestive of a dramatic reduction in flux through AMP deaminase.

Physician supply, treatment, and amputation rates for peripheral arterial disease

OBJECTIVE

To test whether the availability of vascular surgeons and interventional radiologists in a region affects revascularization and amputation rates for patients with peripheral arterial disease (PAD).

METHODS

We identified all patients with PAD in the Medicare claims database in 1994 and tracked their claims through 1999. We aggregated risk-adjusted data on the 143,202 patients who survived through 1999 by Hospital Referral Region and merged this data with information on local physician supply and other regional characteristics. Instrumental variables analysis was used to account for unobserved illness severity. Main outcome measures were risk-adjusted rates of lower extremity bypass surgery, angioplasty, and amputation by region.

RESULTS

Increasing vascular surgeon supply in a region by approximately one standard deviation (.30/10,000 Medicare beneficiaries) is associated with a 0.9 percentage point increase in bypass surgery rates and a 1.6 percentage point reduction in amputation rates. We find weaker evidence that greater availability of interventional radiologists increases angioplasty rates and reduces amputation rates. Factors reflecting regional attractiveness, such as the rating of a region based on climate, recreation, crime, and other attributes, were strong independent predictors of the number of vascular surgeons and interventional radiologists in an area.

CONCLUSIONS

Availability of specialists affects outcomes for PAD patients. Regional variability in specialists who treat PAD is influenced by factors other than regional medical needs. Policies aimed at increasing the supply of vascular surgeons and interventional radiologists and their provision of bypass surgery in underserved areas may help to reduce regional disparities in amputation.

Peripheral Angioplasty as the First-choice Revascularization Procedure in Diabetic Patients with Critical Limb Ischemia: Prospective Study of 993 Consecutive Patients Hospitalized and Followed Between 1999 and 2003

OBJECTIVE

To evaluate the effectiveness of peripheral angioplasty (PTA) as the first-choice revascularisation procedure in diabetic patients with critical limb ischemia (CLI).

DESIGN

Prospective study.

METHODS

PTA was employed as first choice revascularisation in a consecutive series of diabetic patients hospitalized for CLI between January 1999 and December 2003.

RESULTS

PTA was successful performed in 993 patients. Seventeen (1.7%) major amputations were carried out. One death and 33 non-fatal complications were observed. Mean follow-up was 26+/-15 months. Clinical restenosis was observed in 87 patients. The 5 years primary patency was 88%, 95% CI 86-91%. During follow-up 119 (12.0%) patients died at a rate of 6.7% per year.

CONCLUSIONS

PTA as the first choice revascularisation procedure is feasible, safe and effective for limb salvage in a high percentage of diabetic patients. Clinical restenosis was an infrequent event and PTA could successfully be repeated in most cases.

Management of Peripheral Vascular Disease

The management of patients with peripheral arterial occlusive disease (PAD) has to be planned in the context of natural history, epidemiology, and apparent risk factors that predict deterioration. The ankle-brachial index to date has proved to be the most effective, accurate, and practical method of PAD detection. Given that PAD is a powerful indicator of systemic atherosclerosis and (independent of symptoms) is associated with an increased risk of myocardial infarction and stroke, as well as a six times greater likelihood of death, the prevalence and demographic distribution of measurable PAD becomes particularly relevant. Reliable information on interventions to confer symptom relief is much weaker and reflects discrepancies between published reports from centers of excellence and the experience of patients routinely treated in communities around the world. The impact of newer treatment modalities, such as complex endovascular procedures and therapeutic angiogenesis, has been a subject of recent controversy.

Leg ischemia: assessment with MR angiography and spectroscopy

PURPOSE

To prospectively determine reproducibility of magnetic resonance (MR) angiography and MR spectroscopy of deoxymyoglobin in assessment of collateral vessels and tissue perfusion in patients with critical limb ischemia (CLI) and to follow changes in patients undergoing intramuscular vascular endothelial growth factor (pVEGF)-C gene therapy, percutaneous transluminal angioplasty, supervised exercise training, or no therapy.

MATERIALS AND METHODS

Study and gene therapy protocols were approved, and all patients gave written informed consent. To determine repeatability and reproducibility, seven patients underwent MR angiography and five underwent MR spectroscopy. The techniques were used to judge disease progress in 12 other patients with or without therapy: MR angiography to help determine change in visualization of collateral vessels and MR spectroscopy to help assess change in perfusion at proximal and distal calf levels. MR angiographic results were subjectively analyzed by three blinded readers. Intraobserver variability was expressed as 95% confidence interval (CI) (n=7); interobserver variability, as kappa statistic (n=15). Reexamination variability of MR spectroscopy was given as 95% CI for subsequent recovery times, and correlation with disease extent was calculated with Kendall taub rank correlation. Fisher-Yates test was used to correlate changes with pressure measurements and clinical course.

RESULTS

Intraobserver and interobserver concordance was sensitive for detection of collateral vessels. Intraobserver agreement was 85.7% (95% CI: 42.1%, 99.6%). Interobserver agreement was high for small collateral vessels (kappa=0.74, P <.001) and fair for large collateral vessels (kappa=0.36, P=.002). MR spectroscopy was reproducible (95% CI: +/-26 seconds for proximal, +/-21 seconds for distal) and showed a correlation with disease extent (proximal calf, taub=0.84, P <.001; distal calf, taub=0.68, P=.04). Small collateral vessels increased over time (P=.04) but did not correlate with pressure measurements and clinical course. Recovery time correlated with clinical course (proximal calf, P=.03; distal calf, P=.005).

CONCLUSION

MR angiography and MR spectroscopy of deoxymyoglobin can help document changes in visualization of collateral vessels and tissue perfusion in patients with CLI.

Endovascular Interventions in Iliac and Infrainguinal Occlusive Artery Disease

Percutaneous endovascular procedures are increasingly applied to treat symptomatic peripheral occlusive artery disease. While the primary technical success and recanalization rates in iliac and infrainguinal interventions are high, differences in the long-term patency rates exist with respect to the anatomic localization, separating the iliac, femoropopliteal, and infrapopliteal arterial regions. In iliac arteries, even complex lesions can be recanalized with good long-term patency rates, especially when using self-expanding nitinol stents. In the infrainguinal arteries the method of choice is still under debate (e.g., balloon angioplasty vs stent implantation). A high restenosis rate represents one of the major limitations in femoropopliteal and infrapopliteal interventions. Therefore, additional methods and treatment strategies for peripheral interventions with the potential for future applications are under investigation and will be discussed such as drug-eluting stents, brachytherapy, subintimal angioplasty, laser angioplasty, atherectomy/thrombectomy, cutting balloon, polytetrafluoroethylene (PTFE)-covered stent grafts, biodegradable stents, and cryoplasty. The increasing amount of data on successful peripheral interventions supports the necessity to adapt and reevaluate the current consensus guidelines that were put together in 2000.

The role of infrapopliteal angioplasty

Infrapopliteal percutaneous transluminal angioplasty (PTA) is currently indicated in patients with critical limb ischaemia (CLI). It may be performed after femoral angioplasty or bypass surgery, to improve outflow and hence patency of the proximally treated segment. Patients with CLI are typically elderly with multiple co-morbidities and limited life expectancy and therefore, a procedure, which is minimally invasive with reduced morbidity and mortality but lesser long-term patency, may be more appropriate than a more invasive procedure with better long-term patency. Clinical success is superior to angiographic patency, because once healing has occurred, should the artery restenose or occlude, collateral flow can be sufficient to preserve tissue integrity if there is no further injury. Although no prospective randomized trials have been performed, the reported limb-salvage rates of PTA are comparable with surgery. As PTA carries a lower morbidity and mortality, shorter hospital stay and does not preclude surgery, it is ideal for this group of patients who are high-risk surgical candidates. Improvements in guide-wire and catheter technology and recanalization techniques mean that very long stenoses or occlusions, and multiple lesions can be treated successfully. At the current time, PTA is the treatment of choice for infrapopliteal occlusive disease; experience with the use of stents in this territory is increasing but currently insufficient to justify their primary use.

Internal thoracic artery collateral to the external iliac artery in chronic aortoiliac occlusive disease

OBJECTIVE

To evaluate the incidence and angiographic findings of the collateral pathway involving the internal thoracic artery in patients with chronic aortoiliac occlusive disease.

MATERIALS AND METHODS

Between March 2000 and Februrary 2001, 124 patients at our hospital underwent angiographic evaluation of chronic aortoiliac occlusive disease, and in 15 of these complete obstruction or severe stenosis of the aortoiliac artery was identified. The aortograms and collateral arteriograms obtained, including internal thoracic arteriograms, as well as the medical records of the patients involved, were evaluated.

RESULTS

In nine patients there was complete occlusion of the infrarenal aorta, or diffuse stenosis of 75% or more in the descending thoracic aorta, and in the other six, a patent aorta but complete occlusion or stenosis of 75% or more of the common iliac artery was demonstrated. Collateral perfusion via hypertrophied internal thoracic arteries and rich anastomoses between the superior and inferior epigastric arteries, reconstituting the external iliac artery, were noted in all fifteen patients, regardless of symptom duration, which ranged from six months to twelve years.

CONCLUSION

In patients with chronic aortoiliac occlusive disease, the internal thoracic artery, along with visceral collaterals and those from the contralateral side, is one of the major parietal collateral pathways.

Wireless laser-assisted angioplasty of the superficial femoral artery in patients with critical limb ischemia who have failed conventional percutaneous revascularization

Percutaneous revascularization has become an effective treatment for patients suffering from chronic critical limb ischemia (CLI) due to chronic atherosclerotic obstructions, including total occlusions. Unlike other vascular beds, total chronic occlusions of the femoropopliteal arteries are frequently found in patients with severe claudication or CLI. As a consequence, patients with long chronic total occlusions of the femoropopliteal arteries are generally not considered optimal candidates for percutaneous revascularization and are frequently referred for surgical revascularization. In the present study, we sought to evaluate the feasibility, safety, and outcome of a modified wireless laser ablation technique to recanalize total occlusions in patients with CLI who had failed conventional percutaneous techniques for limb salvage. Procedural success, complications, actuarial freedom of limb loss, and surgical revascularization were evaluated in 25 patients after a mean follow-up of 13 +/- 8 months. Procedural success was achieved in 21 patients (84%). Actuarial freedom from surgical revascularization or limb loss was 72%. There was one vascular perforation. No deaths or distal embolization occurred. Three patients (12%) required limb amputation during follow-up, whereas four patients (16%) had surgical revascularization in the presence of feasible vascular targets. Limb salvage was achieved in 88% of patients when laser recanalization was combined with surgical revascularization. These results suggest that the use of laser ablation is safe and facilitates angioplasty and stenting in patients with CLI that failed conventional endovascular revascularization. This technique might prevent limb loss in patients with CLI due to femoropopliteal total occlusions, particularly in patients with unsuitable anatomy for surgical revascularization.

Gene therapy for cardiovascular angiogenesis

Atherosclerosis and endothelial dysfunction are responsible for the pathophysiologic basis of the spectrum of cardiovascular disorders including ischaemic heart disease (IHD), the leading cause of morbidity and mortality in the US. There have been major advances, including the use of pharmacotherapy, coronary and peripheral percutaneous transluminal interventions (PTI), coronary and peripheral bypass surgery and primary/secondary prevention measures. There are, however, multiple unmet needs: IHD refractory to medical therapy and unsuitable for revascularisation; critical limb ischaemia unsuitable for PTI or surgery; restenosis; ischaemic/diabetic neuropathy and heart failure. Cardiovascular gene therapy (GT) with vascular endothelial growth factor (VEGF) has yielded improved perfusion and reduced ischaemia in preclinical models of IHD. Several preclinical studies and Phase I and II clinical trials have shown the safety and therapeutic potential of GT in the treatment of IHD, peripheral arterial disease (PAD), restenosis, and ischaemic and diabetic neuropathy, pointing to the need for Phase III clinical trials.

First case reports of controlled blunt microdissection for percutaneous transluminal angioplasty of chronic total occlusions in peripheral arteries

Percutaneous transluminal angioplasty (PTA) can fail to revascularize peripheral arteries when a chronic total occlusion (CTO) cannot be crossed by guidewires. This article describes application of a new controlled blunt microdissection (CMD) catheter designed to cross CTOs. Two men presenting with severe claudication had iliac CTOs that resisted crossing with guidewires. Using standard techniques, the CMD catheter was advanced to the CTO. Following attempts to cross the CTO with guidewires, the jaw of the CMD distal assembly was actuated, advancing through the CTO as plaque was blunt-dissected. After angioplasty and stenting, restored distal flow was restored. Ischemic symptoms had not recurred at 1- and 28-month follow-up. The concept of blunt intraluminal microdissection has been applied to convert failing to successful PTA of peripheral arteries. CTOs that had resisted guidewire crossing were successfully crossed using the CMD catheter, allowing treatment by angioplasty and stenting.