Faculty Bibliography

OBJECTIVE:The evaluation of patency rates of intraluminal versus subintimal endovascular revascularization of long femoropopliteal (FP) lesions. BACKGROUND:Chronic total occlusions (CTO) of the FP artery in peripheral interventions are crossed either with a support catheter-guidewire based technique or subintimal dissection and re-entry device assisted approach. Both techniques have a high procedural success rate, but their long term patency is not well studied. There is also lack of comparative data addressing the patency of long non-CTO vs. CTO occlusions. METHODS:We performed a single center retrospective analysis, studying the patency rates in 215 patients (254 limbs) with TASC C and D FP lesions treated with stents. There were 3 patient groups: without CTO (non-CTO); CTO crossed using support catheter and guide-wire (CTO-SW) and CTO crossed with a re-entry device (CTO-RE). RESULTS:There were 155 limbs in CTO-SW group; 50 in CTO-RE group and 49 in non-CTO. Lesion length (mean±SD) was 251.81±7.48mm in CTO-SW group; 280±13.18mm in CTO-RE group and 248.77±13.31 in non-CTO group (p=non-significant). In-stent restenosis (ISR) at a mean follow-up of 19.26±16.14months did not differ between groups occurring in 23 (47%) limbs in non-CTO; 66 (42%) in CTO-SW; and 24 (48%) in CTO-RE. Smoking and stent fracture were predictors of ISR by multivariate analysis. CONCLUSION/CONCLUSIONS:In patients with long FP lesions, ISR rates were similar between patients with and without CTO. In the CTO group mid-term vessel patency was not affected by the crossing technique utilized.

OBJECTIVE: We describe a novel approach for the endovascular treatment of femoral artery occlusion as a result of Angio-Seal closure device deployment. BACKGROUND: Angio-Seal is the most commonly used vascular closure device following percutaneous coronary and peripheral catheterizations worldwide. A rare complication of Angio-Seal deployment is an occlusion of the femoral artery leading to limb ischemia requiring revascularization. Given its unique ability to cut both atherosclerotic plaque and the Angio-Seal anchor with a collagen plug at operator-directed planes, TurboHawk/HawkOne atherectomy device can be a fast and effective approach to treat Angio-Seal-associated femoral artery occlusions. METHODS: We studied 13 consecutive patients who developed Angio-Seal-associated femoral artery occlusions that occurred from 3 hours to several weeks after catheterization. These patients were successfully treated with TurboHawk/HawkOne directional atherectomy followed by balloon angioplasty with no complications. During a mean follow-up period of 20.4 +/- 17.3 months, 12 patients remained claudication free with no evidence of obstructive arterial disease of the treated segment on imaging studies. One patient developed restenosis that was treated with repeat atherectomy and balloon angioplasty following which he was asymptomatic at follow-up. CONCLUSION: The use of directional atherectomy followed by balloon angioplasty is a quick, safe, and effective endovascular approach to treating Angio-Seal-associated femoral artery occlusions. It is associated with an excellent success rate, no complications, and good midterm outcomes.

There continues to remain uncertainty regarding the effect of percutaneous coronary intervention (PCI) vs medical therapy in patients with stable angina. We therefore performed a systematic review and study-level meta-analysis of randomized controlled trials of patients with stable angina comparing PCI vs medical therapy for each of the following individual outcomes: all-cause mortality, cardiovascular (CV) mortality, myocardial infarction (MI), and angina relief. We used 8 strategies to identify eligible trials including bibliographic database searches of MEDLINE, PubMed, EMBASE, and the Cochrane Controlled Trials Registry until November 2011. Two independent reviewers undertook decisions about study eligibility and data abstraction. Data were pooled using a random effects model. Ten prospective randomized controlled trials fulfilled our eligibility criteria and they included a total of 6752 patients. We did not detect differences between PCI vs medical therapy for all-cause mortality (663 events; relative risk [RR], 0.97 [confidence interval (CI), 0.84-1.12]; I(2) = 0%), CV mortality (214 events; RR, 0.91 [CI, 0.70-1.17]; I(2) = 0%), MI (472 events; RR, 1.09 [CI, 0.92-1.29]; I(2) = 0%), or angina relief at the end of follow-up (2016 events; RR, 1.10 [CI, 0.97-1.26]; I(2)=85%). PCI was not associated with reductions in all-cause or CV mortality, MI, or angina relief. Considering the cost implication and the lack of clear clinical benefit, these findings continue to support existing clinical practice guidelines that medical therapy be considered the most appropriate initial clinical management for patients with stable angina.

Previous studies have suggested that percutaneous coronary intervention (PCI) decreases long-term mortality in patients with silent myocardial ischemia (SMI), but whether PCI specifically decreases mortality when added to intensive medical therapy is unknown. We performed a post hoc analysis of clinical outcomes in patients in the COURAGE trial based on the presence or absence of anginal symptoms at baseline. Asymptomatic patients were classified as having SMI by electrocardiographic ischemia at rest or reversible stress perfusion imaging (exercise-induced or pharmacologic). Study end points included the composite primary end point (death or myocardial infarction [MI]); individual end points of death, MI, and hospitalization for acute coronary syndrome; and need for revascularization. Of 2,280 patients 12% (n = 283) had SMI and 88% were symptomatic (n = 1,997). There were no between-group differences in age, gender, cardiac risk factors, previous MI or revascularization, extent of angiographic disease, or ischemia by electrocardiogram or imaging. Compared to symptomatic patients, those with SMI had fewer subsequent revascularizations (16% vs 27%, p <0.001) regardless of treatment assignment and fewer hospitalizations for acute coronary syndrome (7% vs 12%, p <0.04). No significant differences in outcomes were observed between the 2 treatment groups, although there was a trend toward fewer deaths in the PCI group (n = 7, 5%) compared to the optimal medical therapy (OMT) group (n = 16, 11%, p = 0.12). In conclusion, addition of PCI to OMT did not decrease nonfatal cardiac events in patients with SMI but showed a trend toward fewer deaths. Although underpowered, given similar outcomes in other small studies, these findings suggest the need for an adequately powered trial of revascularization versus OMT in SMI patients.

Skeletal muscle injury resulting in tissue loss poses unique challenges for surgical repair. Despite the regenerative potential of skeletal muscle, if a significant amount of tissue is lost, skeletal myofibers will not grow to fill the injured area completely. Prior work in our lab has shown the potential to fill the void with an extracellular matrix (ECM) scaffold, resulting in restoration of morphology, but not functional recovery. To improve the functional outcome of the injured muscle, a muscle-derived ECM was implanted into a 1 x 1 cm(2), full-thickness defect in the lateral gastrocnemius (LGAS) of Lewis rats. Seven days later, bone-marrow-derived mesenchymal stem cells (MSCs) were injected directly into the implanted ECM. Partial functional recovery occurred over the course of 42 days when the LGAS was repaired with an MSC-seeded ECM producing 85.4 +/- 3.6% of the contralateral LGAS. This was significantly higher than earlier recovery time points (p < 0.05). The specific tension returned to 94 +/- 9% of the contralateral limb. The implanted MSC-seeded ECM had more blood vessels and regenerating skeletal myofibers than the ECM without cells (p < 0.05). The data suggest that the repair of a skeletal muscle defect injury by the implantation of a muscle-derived ECM seeded with MSCs can improve functional recovery after 42 days.

Exercise and physical strenuous activity have been demonstrated to increase the serum TNF-alpha and IL-6. Regular physical training is expected to attenuate such a response. This study was undertaken to understand the impact of regular exercise training on IL-6 and TNF-alpha in athletes and non-athletes. Ten athletes, who have been on regular training for the past 6 months, and 10 age- and sex-matched subjects (non-athlete group) who had no practice of regular exercise, were recruited. Both were subjected to undergo the same frequency level of strenuous exercise. Blood samples were collected; one before strenuous exercise and the other after the exercise. Plasma cytokines, IL-6 and TNF-alpha, were estimated using Sandwich ELISA method. All participants in the study were male with the athletes' age being 18.00+/-1.3years (mean+/-SD) and the non-athletes were aged 20.00+/-0.6years (mean+/-SD). Majority of the athletes and non-athletes demonstrated a rise in IL-6 and a fall in TNF-alpha levels. Further, the athletes showed a lesser magnitude of change in the cytokine levels following a longer duration of exercise than non-athletes. Athletes appear to have an attenuated cytokine response. Regular physical training has been demonstrated to attenuate the immune response to exercise in either direction.