Luis R. Leon

Contemporary outcomes after superficial femoral artery angioplasty and stenting: The influence of TASC classification and runoff score

OBJECTIVE A recent randomized trial suggested nitinol self-expanding stents (SES) were associated with reduced restenosis rates compared with simple percutaneous transluminal angioplasty (PTA). We evaluated our results with superficial femoral artery (SFA) SES to determine whether TransAtlantic InterSociety Consensus (TASC) classification, indication for intervention, patient risk factors, or Society of Vascular Surgery (SVS) runoff score correlated with patency and clinical outcome, and to evaluate if bare nitinol stents or expanded polytetrafluoroethylene (ePTFE) covered stent placement adversely impacts the tibial artery runoff. METHODS A total of 109 consecutive SFA stenting procedures (95 patients) at two university-affiliated hospitals from 2003 to 2006 were identified. Medical records, angiographic, and noninvasive studies were reviewed in detail. Patient demographics and risk factors were recorded. Procedural angiograms were classified according to TASC Criteria (I-2000 and II-2007 versions) and SVS runoff scores were determined in every patient; primary, primary-assisted, secondary patency, and limb salvage rates were calculated. Cox proportional hazard model was used to determine if indication, TASC classification, runoff score, and comorbidities affected outcome. RESULTS Seventy-one patients (65%) underwent SES for claudication and 38 patients (35%) for critical limb ischemia (CLI). Average treatment length was 15.7 cm, average runoff score was 4.6. Overall 36-month primary, primary-assisted, and secondary rates were 52%, 64%, and 59%, respectively. Limb salvage was 75% in CLI patients. No limbs were lost following interventions in claudicants (mean follow-up 16 months). In 24 patients with stent occlusion, 15 underwent endovascular revision, only five (33%) ultimately remained patent (15.8 months after reintervention). In contrast, all nine reinterventions for in-stent stenosis remained patent (17.8 months). Of 24 patients who underwent 37 endovascular revisions for either occlusion or stenosis, eight (35%) had worsening of their runoff score (4.1 to 6.4). By Cox proportional hazards analysis, hypertension (hazard ratio [HR] 0.35), TASC D lesions (HR 5.5), and runoff score > 5 (HR 2.6) significantly affected primary patency. CONCLUSIONS Self-expanding stents produce acceptable outcomes for treatment of SFA disease. Poorer patency rates are associated with TASC D lesions and poor initial runoff score; HTN was associated with improved patency rates. Stent occlusion and in-stent stenosis were not entirely benign; one-third of patients had deterioration of their tibial artery runoff. Future studies of SFA interventions need to stratify TASC classification and runoff score. Further evaluation of the long-term effects of SFA stenting on tibial runoff is needed.

Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate

OBJECTIVE It has been suggested that endovascular aneurysm repair (EVAR) in concert with serial contrast-enhanced computed tomography (CT) surveillance adversely impacts renal function. Our primary objectives were to assess serial renal function in patients undergoing EVAR and open repair (OR) and to evaluate the relative effects of method of repair on renal function. METHODS A thorough retrospective chart review was performed on 223 consecutive patients (103 EVAR, 120 OR) who underwent abdominal aortic aneurysm (AAA) repair. Demographics, pertinent risk factors, CT scan number, morbidity, and mortality were recorded in a database. Baseline, 30- and 90-day, and most recent glomerular filtration rate (GFR) were calculated. Mean GFR changes and renal function decline (using Chronic Kidney Disease [CKD] staging and Kaplan-Meier plot) were determined. EVAR and OR patients were compared. CKD prevalence (>or=stage 3, National Kidney Foundation) was determined before repair and in longitudinal follow-up. Observed-expected (OE) ratios for CKD were calculated for EVAR and OR patients by comparing observed CKD prevalence with the expected, age-adjusted prevalence. RESULTS The only baseline difference between EVAR and OR cohorts was female gender (4% vs 12%, P = .029). Thirty-day GFR was significantly reduced in OR patients (P = .047), but it recovered and there were no differences in mean GFR at a mean follow-up of 23.2 months. However, 18% to 39% of patients in the EVAR and OR groups developed significant renal function decline over time depending on its definition. OE ratios for CKD prevalence were greater in AAA patients at baseline (OE 1.28-3.23, depending upon age group). During follow-up, the prevalence and severity of CKD increased regardless of method of repair (OE 1.8-9.0). Deterioration of renal function was independently associated with age >70 years in all patients (RR 2.92) and performance of EVAR compared with OR (RR 3.5) during long-term follow-up. CONCLUSIONS Compared with EVAR, OR was associated with a significant but transient fall in GFR at 30 days. Renal function decline after AAA repair was common, regardless of method, especially in patients >70 years of age. However, the renal function decline was significantly greater by Kaplan-Meier analysis in EVAR than OR patients during long-term follow-up. More aggressive strategies to monitor and preserve renal function after AAA repair are warranted.

Wire-Interwoven Nitinol Stent Outcome in the Superficial Femoral and Proximal Popliteal Arteries Twelve-Month Results of the SUPERB Trial

Background—Stent-based therapy in the superficial femoral and popliteal arteries in patients with peripheral artery disease is compromised by restenosis and risk of stent fracture or distortion. A novel self-expanding nitinol stent was developed that incorporates an interwoven-wire design (Supera stent, IDEV Technologies, Inc, Webster, TX) to confer greater radial strength, flexibility, and fracture resistance. Methods and Results—This prospective, multicenter, investigational device exemption, single-arm trial enrolled 264 patients with symptomatic peripheral artery disease undergoing percutaneous treatment of de novo or restenotic lesions of the superficial femoral or proximal popliteal (femoropopliteal) artery. Freedom from death, target lesion revascularization, or any amputation of the index limb at 30 days (+7 days) postprocedure was achieved in 99.2% (258/260) of patients (P<0.001). Primary patency at 12 months (360±30 days) was achieved in 78.9% (180/228) of the population (P<0.001). Primary patency by Kaplan–Meier analysis at 12 months (360 days) was 86.3%. No stent fracture was observed by independent core laboratory analysis in the 243 stents (228 patients) evaluated at 12 months. Clinical assessment at 12 months demonstrated improvement by at least 1 Rutherford–Becker category in 88.7% of patients. Conclusions—The SUPERB Trial, an investigational device exemption study using an interwoven nitinol wire stent in the femoropopliteal artery, achieved the efficacy and safety performance goals predesignated by the Food and Drug Administration. On the basis of the high primary patency rate, absence of stent fracture, and significant improvements in functional and quality-of-life measures, the Supera stent provides safe and effective treatment of femoropopliteal lesions in symptomatic patients with peripheral artery disease. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00933270.

Patterns of Venous Reflux and Obstruction in Patients With Skin Damage Due to Chronic Venous Disease

Identified were characteristics of individuals with skin damage related to chronic venous disease. Patients with chronic venous disease (n = 164) were evaluated with duplex ultrasound imaging and were placed in classes 4, 5, and 6 according to the CEAP classification. Their findings were compared with 100 class 2 controls. The prevalence of deep venous thrombosis was higher in the study group (23.7%) versus controls (5.1%; P < .0001), as was the prevalence of deep, perforator, and combined patterns of disease (P < .0001, P < .0007, and P < .0001). The mean duration of disease in controls 2 was shorter compared with the study group (P = .0019). The prevalence of reflux and obstruction within the study group was higher than in controls (P = .0021). Skin changes accurately reflect severity of chronic venous disease. Superficial and perforator vein reflux is the major cause of disease.

Secondary chronic venous disease progresses faster than primary

PURPOSE To compare the progression rate of primary with secondary chronic venous disease (CVD). METHODS Patients with a first episode of proximal deep vein thrombosis (DVT), diagnosed by duplex ultrasound (DU) were included in group A - secondary CVD (41 patients, 46 limbs). DU was performed at least once, 1 year after the diagnosis, and repeated at 5 years. Group B - primary CVD (41 patients, 50 limbs) included age- and sex-matched patients with primary CVD and duration of 5 to 10 years to be comparable with that of group A. They had no history of DVT and were referred for reflux evaluation. All their veins were free of postthrombotic signs upon DU examination. Group C (15 patients, 30 limbs) had no signs and symptoms of CVD and were examined at baseline and 5 years later. This group of patients was also matched for age and sex. Clinic examinations were performed at 3, 6, and 12 months and yearly thereafter. The CEAP system was used to grade disease severity. The proximal veins were divided in the CFV, FV, and POPV segments for analysis. Thrombosed veins were subsequently graded as complete, partial, and fully recanalized. Recurrent DVT cases were also recorded. RESULTS At 5-year follow-up, the prevalence of skin damage was significantly higher in group A (11/46 vs group B 3/50, P = .019 and vs group C 0/30, P < .01). The progression to skin damage in group A was faster as it changed from 4% (2/46) at 1 year (P = 0.014) compared with the two other groups. In group A, 22 limbs had reflux, three had obstruction, 19 had combine reflux and obstruction, and two were normal. In group B, superficial, deep, and perforator vein reflux were seen in 50, 4, and 15 limbs, respectively. In group C, five limbs in four patients developed superficial reflux in which only two had symptoms. The CEAP class in this group was C0N = 25, C1 = 3, and C2 = 2. In group A, skin damage was significantly higher in limbs with combined proximal and distal obstruction as well as in limbs with combined reflux and obstruction (P = .012 and P = 0.013, respectively). DVT was found in 108 segments (25 CFV, 40 FV, and in 43 POPV), 82 at the first episode and 26 as an ipsilateral recurrence. Ipsilateral and contralateral recurrences were seen in 21.9% and 9.8% of patients, respectively. Complete recanalization occurred in 43 segments, partial in 55, and none in 10. Reflux occurred in 85.5% and 60.5% of the partially and completely recanalized segments, respectively (P = .006). CONCLUSIONS The progression of CVD is more rapid in postthrombotic limbs when compared with those with primary CVD. The incidence of CVD in normal individuals is small and its progression is slow. Poor prognostic factors for progression to advanced CVD include the combination of reflux and obstruction, ipsilateral recurrent DVT, and multi-segmental involvement.

Results of the Nellix system investigational device exemption pivotal trial for endovascular aneurysm sealing

OBJECTIVE The Nellix EndoVascular Aneurysm Sealing system (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) endovascular repair whereby biocompatible polymer is employed to exclude and to seal the AAA sac. We report 30-day results of the U.S. pivotal trial. METHODS Consecutive, eligible, consenting patients were enrolled at 29 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with aortic neck length ≥10 mm and angle to the sac ≤60 degrees, aortic neck diameter of 18 to 32 mm, aneurysm blood lumen diameter ≤6 cm, common iliac artery lumen diameter of 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine level ≤2 mg/dL. Follow-up at 30 days included clinical assessment and computed tomography angiography evaluation of endoleaks and device integrity as assessed by a core laboratory. The primary safety end point is the incidence of independently adjudicated 30-day major adverse events (MAEs), with success defined as superiority with reference to the Society for Vascular Surgery open repair control group (56%). RESULTS Between January and November 2014, 150 trial patients having a mean AAA diameter of 5.8 cm were enrolled and treated with the Nellix system with 100% procedural success. One early death (0.7%) occurred secondary to multisystem organ failure. All 149 surviving patients completed 30-day follow-up. There were no aneurysm ruptures, conversions, limb thromboses, stent fractures, or stent kinking. Five early MAEs occurred in four patients (2.7%) and included one death, bowel ischemia (1), renal failure (2), and respiratory failure (1). One (0.7%) secondary intervention to treat inadvertent coverage of a renal artery was performed. The core laboratory identified nine (6%) endoleaks (one type I, eight type II) on 30-day computed tomography angiography. Freedom from MAE was 97.3% (95% confidence interval, 93.3%-99.0%). CONCLUSIONS In selected patients, perioperative outcomes with the Nellix system for endovascular aneurysm sealing are encouraging, with very low 30-day morbidity and mortality and high procedural success. The primary safety end point has been achieved. Longer term follow-up is in progress.

Preliminary results of the initial United States experience with the Supera woven nitinol stent in the popliteal artery

BACKGROUND Popliteal artery stenting is not routinely performed due to concerns related to the high mobility of the knee joint and the potential for external stent compression, fractures, and occlusion. Open bypass is traditionally considered the gold standard for popliteal artery atherosclerotic lesions. The Supera stent (IDEV Technologies Inc, Webster, Tex) was developed to provide superior radial strength, fracture resistance, and flexibility compared with laser-cut nitinol stents. This study represents the initial United States experience in the management of popliteal artery atherosclerotic disease with the Supera interwoven wire stent. METHODS Patients undergoing stent implantation in the 20-month period after the 2008 Food and Drug Administration clearance were included. Medical records, radiographic imaging, and procedural data were examined. Procedural angiograms were classified according to Trans-Atlantic Inter-Society Consensus criteria. Patency and limb loss rates were calculated using Kaplan-Meier analysis. RESULTS A total of 39 stents were placed in 34 patients due to isolated popliteal artery occlusive disease. Clinical follow-up was a mean of 12.7 months (range, 0.2-33.7 months), and radiologic follow-up was a mean of 8.4 months (range, 0-26.8 months). Most patients had critical limb ischemia (CLI), with tissue loss (38.2%) or rest pain (35.3%) as the indication for intervention. In 20 patients (58.8%), the most distal end of the stent(s) landed in the below-the-knee popliteal segment, 12 (35.3%) landed in the above-the-knee segment, and two (5.9%) landed precisely at the knee. Other than angioplasty and stenting, 47% of patients did not receive any adjuvant concomitant therapy in the treated leg. Two patients underwent concomitant atherectomy of the popliteal segment. Primary, primary assisted, and secondary patency rates by duplex ultrasound imaging were 79.2%, 88.1% and 93%, respectively, by Kaplan-Meier estimates, with a mean stented length of 12 cm. Six instances of stent occlusion were noted, and six patients were identified with hemodynamically significant in-stent stenosis. Three patients sustained limb loss (8.8%), two related to uncontrolled infections, and one due to perioperative ischemic complications (both with patent stents at the time of limb loss). The overall mortality was 8.8% during the study period. Knee roentgenography was performed in all but one patient, and no stent fractures were identified. CONCLUSIONS Stenting of the popliteal artery using the Supera stent system appears to be safe and effective. The interwoven stent design may better serve areas under extreme mechanical stress. Our results with this highly diseased patient population justify a prospective trial in this subject.

Diagnosis and Management of Aortic Mycotic Aneurysms

We reviewed all papers most recently reported in the literature (January-December 2008) with regard to infected arterial aneurysms (IAAs) affecting the aorta. Most of the recently reported knowledge is limited to case reports and small series of aortic mycotic aneurysms. Most patients are elderly men and have comorbidities at presentation. Aneurysms were most commonly associated to Salmonella and Staphylococcus. However, several cases of aortic IAAs caused by atypical pathogens were also reported, likely due to an increase in immunosuppressive illnesses, increased life expectancy, improved diagnostic methods, and increasing medical awareness. Open surgical therapy of IAAs remains the gold standard. Some have reported successful outcomes with endovascular methodologies for patients medically compromised or for particular challenging clinical or anatomical scenarios. However, at this time, conclusive evidence is lacking and it should be in general considered a bridge to open repair. The latter should be planned at the earliest possible, when medically permissible.

Arteriovenous Access: Managing Common Problems

The creation and maintenance of hemoaccess occupies a significant portion of most vascular and general surgery practices. In this article, the methods used to detect hemoaccess at risk for failure and the endovascular and surgical techniques used to prolong or restore their patency are reviewed. Also, the management of hemoaccess infection, aneurysmal degeneration, false aneurysm formation, and symptomatic arterial steal syndrome are described.

Tibiopedal Access for Crossing of Infrainguinal Artery Occlusions: A Prospective Multicenter Observational Study

Purpose: To report a prospective, multicenter, observational study (ClinicalTrials.gov identifier NCT01609621) of the safety and effectiveness of tibiopedal access and retrograde crossing in the treatment of infrainguinal chronic total occlusions (CTOs). Methods: Twelve sites around the world prospectively enrolled 197 patients (mean age 71±11 years, range 41-93; 129 men) from May 2012 to July 2013 who met the inclusion criterion of at least one CTO for which a retrograde crossing procedure was planned or became necessary. The population consisted of 64 (32.5%) claudicants (Rutherford categories 2/3) and 133 (67.5%) patients with critical limb ischemia (Rutherford category ≥4). A primary antegrade attempt to cross had been made prior to the tibiopedal attempt in 132 (67.0%) cases. Techniques used for access, retrograde lesion crossing, and treatment were at the operator’s discretion. Follow-up data were obtained 30 days after the procedure. Results: Technical tibiopedal access success was achieved in 184 (93.4%) of 197 patients and technical occlusion crossing success in 157 (85.3%) of the 184 successful tibial accesses. Failed access attempts were more common in women (9 of 13 failures). The rate of successful crossing was roughly equivalent between sexes [84.7% (50/59) women compared to 85.6% (107/125) men]. Technical success did not differ significantly based on a prior failed antegrade attempt: the access success rate was 92.4% (122/132) after a failed antegrade access vs 95.4% (62/65) in those with a primary tibiopedal attempt (p=0.55). Similarly, crossing success was achieved in 82.8% (101/122) after a failed antegrade access vs 90.3% (56/62) for patients with no prior antegrade attempt (p=0.19). Minor complications related to the access site occurred in 11 (5.6%) cases; no patient had access vessel thrombosis, compartment syndrome, or surgical revascularization. Conclusion: Tibiopedal access appears to be safe and can be used effectively for the crossing of infrainguinal lesions in patients with severe lower limb ischemia.