Faculty Bibliography

Popliteal artery aneurysms represent a common pathology that vascular surgeons are often confronted with. However, several issues remain incompletely understood, including indications for intervention and optimal methods of treatment. In the following article, our discussants debate the appropriate management of small popliteal artery aneurysms. Further complicating this discussion is the unclear relationship between popliteal artery aneurysm diameter and subsequent complications. Whereas with abdominal aortic aneurysms diameter is linked to rupture risk, it is less clear with popliteal artery aneurysms where complications are more likely to include thrombosis, embolization, and compression whether aneurysm diameter is accurately predictive. Perhaps other anatomic features should be included in our management algorithms? Regardless, our debaters will try to convince us whether small popliteal artery aneurysms warrant repair or not.

OBJECTIVES: Despite advances in endovascular therapies, critical limb ischemia (CLI) continues to be associated with high morbidity and mortality. Patients without direct revascularization options have the worst outcomes. We sought to explore the feasibility of conducting a definitive trial of a bone marrow-derived cellular therapy for CLI in this "no option" population. METHODS: A pilot, multicenter, prospective, randomized, double-blind, placebo-controlled trial for "no option" CLI patients was performed. The therapy consisted of bone marrow aspirate concentrate (BMAC), prepared using a point of service centrifugation technique and injected percutaneously in 40 injections to the affected limb. Patients were randomized to BMAC or sham injections (dilute blood). We are reporting the 12-week data. RESULTS: Forty-eight patients were enrolled. The mean age was 69.5 years (range, 42-93 years). Males predominated (68%). Diabetes was present in 50%. Tissue loss (Rutherford 5) was present in 30 patients (62.5%), and 18 (37.5%) had rest pain without tissue loss (Rutherford 4). Patients were deemed unsuitable for conventional revascularization based on multiple prior failed revascularization efforts (24 [50%]), poor distal targets (43 [89.6%]), and medical risk (six [12.5%]). Thirty-four patients were treated with BMAC and 14 with sham injections. There were no adverse events attributed to the injections. Renal function was not affected. Effective blinding was confirmed; blinding index of 61% to 85%. Subjective and objective outcome measures were effectively obtained with the exception of treadmill walking times, which could only be obtained at baseline and follow-up in 15 of 48 subjects. This pilot study was not powered to demonstrate statistical significance but did demonstrate favorable trends for BMAC versus control in major amputations (17.6% vs 28.6%), improved pain (44% vs 25%), improved ankle brachial index (ABI; 32.4% vs 7.1%), improved Rutherford classification (35.3% vs 14.3%), and quality-of-life scoring better for BMAC in six of eight domains. CONCLUSIONS: In this multicenter, randomized, double-blind, placebo-controlled trial of autologous bone marrow cell therapy for CLI, the therapy was well tolerated without significant adverse events. The BMAC group demonstrated trends toward improvement in amputation, pain, quality of life, Rutherford classification, and ABI when compared with controls. This pilot allowed us to identify several areas for improvement for future trials and CLI studies. These recommendations include elimination of treadmill testing, stratification by Rutherford class, and more liberal inclusion of patients with renal insufficiency. Our strongest recommendation is that CLI studies that include Rutherford 4 patients should incorporate a composite endpoint reflecting pain and quality of life.

In 2008, the Society for Vascular Surgery published guidelines for the treatment of carotid bifurcation stenosis. Since that time, a number of prospective randomized trials have been completed and have shed additional light on the best treatment of extracranial carotid disease. This has prompted the Society for Vascular Surgery to form a committee to update and expand guidelines in this area. The review was done using the GRADE methodology.[corrected] The perioperative risk of stroke and death in asymptomatic patients must be below 3% to ensure benefit for the patient. Carotid artery stenting (CAS) should be reserved for symptomatic patients with stenosis 50% to 99% at high risk for CEA for anatomic or medical reasons. CAS is not recommended for asymptomatic patients at this time. Asymptomatic patients at high risk for intervention or with <3 years life expectancy should be considered for medical management as first line therapy. In this Executive Summary, we only outline the specifics of the recommendations made in the six areas evaluated. The full text of these guidelines can be found on the on-line version of the Journal of Vascular Surgery at http://journals.elsevierhealth.com/periodicals/ymva.

Management of carotid bifurcation stenosis is a cornerstone of stroke prevention and has been the subject of extensive clinical investigation, including multiple controlled randomized trials. The appropriate treatment of patients with carotid bifurcation disease is of major interest to the community of vascular surgeons. In 2008, the Society for Vascular Surgery published guidelines for treatment of carotid artery disease. At the time, only one randomized trial, comparing carotid endarterectomy (CEA) and carotid stenting (CAS), had been published. Since that publication, four major randomized trials comparing CEA and CAS have been published, and the role of medical management has been re-emphasized. The current publication updates and expands the 2008 guidelines with specific emphasis on six areas: imaging in identification and characterization of carotid stenosis, medical therapy (as stand-alone management and also in conjunction with intervention in patients with carotid bifurcation stenosis), risk stratification to select patients for appropriate interventional management (CEA or CAS), technical standards for performing CEA and CAS, the relative roles of CEA and CAS, and management of unusual conditions associated with extracranial carotid pathology. Recommendations are made using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system, as has been done with other Society for Vascular Surgery guideline documents.[corrected] The perioperative risk of stroke and death in asymptomatic patients must be <3% to ensure benefit for the patient. CAS should be reserved for symptomatic patients with stenosis of 50% to 99% at high risk for CEA for anatomic or medical reasons. CAS is not recommended for asymptomatic patients at this time. Asymptomatic patients at high risk for intervention or with <3 years life expectancy should be considered for medical management as the first-line therapy.

In 2006, the Society for Vascular Surgery began development of clinical practice guidelines to assist clinicians in the process of decision making. The Society selects clinical questions of high impact and evaluates the totality of evidence by identifying and conducting rigorous systematic reviews. Multidisciplinary committees follow the Grading of Recommendations, Assessment, Development and Evaluation framework (GRADE), standard consensus, and voting procedures. Factors other than evidence, including patients' values and preferences and the availability of surgical expertise, are also considered. We describe, in the context of cumulative 4-years' experience, the methods and rigor of current procedures adopted by the Society for Vascular Surgery in developing practice guidelines. We also discuss potential future efforts needed to maximize the quality, adoption, and application of the clinical recommendations.

BACKGROUND: The technique of long segment stenting of the superficial femoral artery (SFA) has been associated with poorer short- and long-term results. The full metal jacket (FMJ) stenting is typically described as long segment continuous stenting of a vessel segment. Initially, this technique was described in percutaneous coronary interventions. However, until recently, FMJ of the SFA has not been studied. We examined our experience with FMJ of the SFA to evaluate the outcomes and the safety of this technique. METHODS: Retrospective data were gathered for peripheral angioplasties and stenting for the period between January 2005 and December 2008. The cases involving FMJ stenting of the SFA were identified by angiographic findings and the operative dictations providing the stent data. Selective FMJ stenting of the SFA was performed for the residual stenosis after balloon angioplasty of the SFA because of either dissection or significant recoil. The cases with concomitant iliac artery angioplasty and/or stenting were excluded from the data set for analysis. The variables for the evaluation were primary patency rate, mortality rate, and limb salvage rate, which were stratified on the basis of the risk factors. RESULTS: A total of 63 cases involving FMJ stenting of the SFA were identified from the database of 707 patients who had peripheral endovascular interventions between January 2005 and December 2008. Average age of the patients was 70 years (range: 52-104 years, SD: 10.1 years). There were no transatlantic inter-society consensus (TASC) A lesions, 11% (7/63) of the lesions were TASC B, 68% (43/63) were TASC C, and 21% (13/63) were TASC D. The median primary patency rate was 9 months (95% CI: 5.06-12.94). The mortality rate was 4% at 6-month follow-up. The limb salvage rate was 85.7%. In all, 65% (41/63) of the patients were claudicants, whereas 23% (15/63) had intervention for some form of tissue loss (ischemic ulcer, gangrene). Associated infrapopliteal intervention was performed in 15.9% of the patients. Average creatinine level was 1.67 (range: 0.7-10.9, SD: 2.03) and 49% (31/63) of the patients had diabetes. The average 6-month patency rate was 55% (SD: 0.5). Multivariate logistic regression analysis showed that diabetes (OR: 0.33, p = 0.044, 95% CI: 0.11-0.97) and a creatinine level of >/=1.6 (OR: 0.16, p = 0.038, 95% CI: 0.03-0.9) were the independent risk factors for loss of patency in <6 months. CONCLUSION: Our experience suggests promising results for the technique of FMJ of the SFA and also that further examination of the technique is warranted.

Infra-popliteal veins include the tibial and peroneal veins, as well as the soleal and gastrocnemial veins collectively known as the calf muscle veins (CMVs). Acute infra-popliteal deep venous thrombi (DVTs) are often considered insignificant with regard to the risk of pulmonary embolism (PE). A retrospective review of 4035 consecutive lower extremity venous duplex scans were made in 3146 hospital patients at our Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)-accredited vascular lab. Seven hundred sixteen (17.7%) duplex scans were positive for acute DVTs, and 112 (2.8%) were associated with PEs. The breakdown of positive duplexes for acute DVTs was as follows: 202 (28.2%) isolated femoral-popliteal DVTs with PE in 23 (11.4%), 304 (42.5%) isolated infra-popliteal DVTs with PE in 24 (7.9%) and 210 (29.3%) multilevel DVTs involving both vein segments (femoral-popliteal and infra-popliteal) with PE in 38 (18.1%). Of the 304 isolated acute infra-popliteal DVTs, 207 (68.1%) were isolated CMV DVTs with evidence of PE in 12 (5.8%). No statistically significant difference (P = 0.27) in the risk of PE between isolated femoral-popliteal and isolated infra-popliteal DVTs was noted. A significant number of patients (5.8%) with isolated CMV DVTs developed PE. Lower limb venous scans for DVTs should evaluate the infra-popliteal veins. Hospitalized patients with infra-popliteal DVTs should receive anticoagulation.

Recanalization after extracranial internal carotid artery (ICA) occlusion is a rare phenomenon and the natural history of the disease is largely unknown. There have been few cases reported in the published data, including early recanalization after a cerebrovascular accident (CVA). We report a case of a 74-year-old man who presented with a CVA and a history of multiple CVAs in the past, the last episode being a year ago. Multiple imaging modalities, including duplex scans, computerized tomographic angiograms, and fluoroscopy-guided angiogram of bilateral carotid arteries, showed occlusion of the left ICA in the past. The duplex scan performed 8 months later demonstrated late spontaneous recanalization of the occluded left ICA. The patient underwent successful carotid endarterectomy. The pathophysiology, natural history, and possible surveillance strategy are discussed in this case report.

OBJECTIVE: Although anticoagulation remains the mainstay of treatment for deep venous thrombosis, the use of inferior vena cava (IVC) filters when anticoagulation has failed or when contraindicated remains a safe and effective treatment. Greenfield (Boston Scientific, Natick, Mass) and TrapEase (Cordis, Bridgewater, NJ) filters are arguably among the most popular filtration devices. The Greenfield filter (12F introducer) has been in use for >30 years and has been well studied. The TrapEase filter (6F introducer) has been used since 2000, with a limited number of studies. Good guidelines to help determine which filter to use in any given situation are lacking; therefore, this randomized study prospectively compared the clinical outcomes (access-site thrombosis, filter thrombosis, and symptomatic pulmonary embolism [PE]) between these filters. METHODS: Between July 2006 and November 2008, 156 patients (63 men, 93 women; mean age, 75 years; range, 38-101 years) were randomized: 84 to Greenfield and 72 to TrapEase IVC filter insertion in the infrarenal position using angiographic guidance. Postoperative follow-up comprised serial lower extremity and IVC/iliac vein (IV) duplex imaging (78.2%) at day 1, week 1, every 3 months for the first year, and every 6 months for the second year; clinical evaluation, and clinic visits. During this period, 349 patients (143 men, 206 women; mean age, 75 years; range, 24-96 years) were not randomized. RESULT: The indications for filter placement, in the 156 randomized patients, were gastrointestinal bleeding, 37; intracranial hemorrhage, 12; free-floating clot, 19; failure of anticoagulation, 29; PE, 27; prophylactic, 4; and others, 32. During a mean 12-month follow-up (range, 0-39 months), symptomatic IVC/IV thrombosis developed in five patients (6.94%) in the TrapEase group and none in the Greenfield group (P = .019). No filter migration, access-site thrombosis, misplacement, or IVC perforation occurred. Recurrent PE was suspected in one of the five patients with IVC/IV thrombosis. Overall mortality was 42.3% (66 patients), and 30-day mortality was 13.5% (21 patients: 10 TrapEase, 11 Greenfield). The study was initially designed to recruit 360 patients in both TrapEase and Greenfield filters in 2 years to demonstrate any statistical significance but was prematurely concluded due to the interim results. CONCLUSION: A higher rate of symptomatic IVC/IV thrombosis is associated with TrapEase filter placement. However, the TrapEase filter still has a selective clinical role in the prevention of thromboembolism in selected patients who are coagulopathic. This is the first randomized prospective study comparing IVC filters since their inception in 1967.