Alexander Shiferson

Prospective randomized study comparing the clinical outcomes between inferior vena cava Greenfield and TrapEase filters

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.

The safety of radiofrequency ablation of the great saphenous vein in patients with previous venous thrombosis

BACKGROUND The safety of radiofrequency ablation (RFA) of the great saphenous vein (GSV) in patients with previous history of deep venous thrombosis (DVT) has not been determined. METHODS From April 2003 to June 2006, 274 patients (68% women; mean age, 60 years +/- 15 years) underwent 293 consecutive RFA procedures. In the first 15 months, the temperature probe was maintained at 85 degrees C, with a pullback rate of 2 cm/min (85 limbs, 30%); we subsequently changed the protocol to 90 degrees C and a pullback rate of 2 to 3 cm/min (205 limbs, 70%). We identified 29 patients (10%) with a history of DVT or duplex scan evidence of post-thrombotic venous disease; these were compared with the remaining 264 (90%). Postprocedural acute thrombotic (AT) events were analyzed. By the CEAP classification, 204 limbs (70%) were C(2) to C(4), and 89 (30%) were C(5) to C(6). Thirty-seven patients (13%) had a history of superficial thrombophlebitis (SVT). Proximal mean GSV diameter was 0.95 +/- 0.29 cm (range, 0.4-2.3 cm). Concomitant procedures included avulsion phlebectomy in 88 limbs (30%) and perforator vein surgery in 4 (1%). RESULTS AT events after RFA were detected in 38 limbs (13%), including thrombus protrusion into the sapheno-femoral junction (SFJ) in 24 (8%), common femoral vein in 7 (2.5%), and calf vein DVT in 7 (2.5%). Overall incidence of AT events in limbs with and without evidence of previous DVT was 7% (2 of 29) and 14% (36 of 264), respectively (P = .36). Variables significantly associated with AT events were previous SVT (10 of 37 [27%] vs 28 of 256 [11%], P = .01), a larger GSV diameter (mean 1.1 +/- .39 vs 0.93 +/- 0.27, P < .01), and first protocol (catheter temperature of 85 degrees C with a slower pullback rate in 18 of 88 [20%] vs 20 of 205 [9.7%], P = .02). Concomitant venous operations were associated with an increase in AT events (23% vs 9%; P < .002). By multivariate analysis, larger proximal GSV diameter and previous SVT remained independently statistically significant (P = .049 and P = .0135, respectively). All AT patients were successfully treated with standard anticoagulation. No pulmonary emboli occurred. CONCLUSION RFA of the GSV in patients with previous venous thromboembolic events is safe and should be offered as an alternative to surgical procedures. These data demonstrate that AT events increase when larger-diameter GSVs are treated.

Limitations of and Lessons Learned from Clinical Experience of 1,020 Duplex Arteriography

Objective: Due to the inherent risks, deficiencies and cost associated with contrast arteriography (CA), our group has been utitilizing duplex arteriography (DA) for evaluating the arteries of the lower extremity for patients undergoing lower extremity revascularization. In an effort to further explore the strengths and weaknesses of DA, we reviewed our evolving experience with DA from January 1, 1998, to January 1, 2005. Patients and Methods: The arterial segments starting from mid-abdominal aorta to the pedal arteries were studied in cross-sectional and longitudinal planes using a variety of scanheads of 7–4, 10–5, 12–5, 5–2 and 3–2 MHz extended operative frequency range to obtain high-quality B-mode, color and power Doppler images as well as velocity spectra. In 906 patients, 1,020 duplex arteriograms were obtained. The ages ranged from 30–98 years old with a mean of 73±11 (SD) years. Fifty percent of the patients were diabetics. Indications for the examination included: tissue loss (409), rest pain (221), claudication (310), acute ischemia (74), popliteal aneurysm (45), SFA aneurysm (2), abdominal aortic aneurysms (AAA) (10) and failing bypass (55). Prior procedures had been performed in 262. DA was performed by six technologists (4 of whom are MDs). In all, 207 DA were performed intraoperatively and the remainder, preoperatively. Results: The resultant procedures based upon DA included: bypass to the popliteal artery (262) and bypass to an infrapopliteal artery (325), endovascular procedures (363), thrombectomy (11), embolectomy (9), inflow bypass procedures to the femoral arteries (46), débridment (4), amputation (8) and no intervention (75). The areas not visualized well included: iliac (73), femoral (26), popliteal (17), and infrapopliteal (221). Additional imaging after DA was deemed necessary in 102 cases to obtain enough information to plan lower extremity revascularization. Factors associated with increased need to obtain CA included: DM (p<.001), infrapopliteal calcification (p<.001), older age (p = .01) and limb threatening ischemia (p<.001). Factors not associated with the need to obtain CA included: which technologist performed the exam, whether the technologist has a medical degree and whether the patient underwent prior revascularization. Conclusions: In 90% of patients reviewed, DA is able to obtain the needed information to plan lower extremity revascularization. Severe tibial vessel calcification is the most common cause of an incomplete DA exam and determines when alternative imaging modalities need to be obtained.

Pulmonary Embolism Without Deep Venous Thrombosis

BACKGROUND To identify patients with pulmonary embolism (PE) without deep venous thrombosis (DVT), and to compare them with those with an identifiable source on upper (UED) and lower-extremity venous duplex scans (LED). METHODS We performed a retrospective review of 2700 computed tomography angiograms of the chest between January 2008 and September 2010 and identified 230 patients with PE. We then evaluated the results of UED and LED and divided the patients into four groups based on the results of their duplex studies. We compared patients with PE and DVT with those with PE and no DVT in terms of age, gender, size and location of PE, critical illness, malignancy, and in-hospital mortality. RESULTS We identified 152 women and 78 men (mean age, 68 years) with PE. One hundred thirty-one patients had a documented source of PE (group 1). Fifty-three patients had negative LED results, but did not undergo UED (group 2). Thirty-one patients did not undergo either LED or UED (group 3). Seven men and eight women had no documented source of PE on UED and LED (group 4). Ten of 15 patients in group 4 had a documented malignancy listed as one of their diagnoses. Because patients in groups 2 and 3 did not undergo complete duplex studies, we excluded them from our analysis. We then reviewed the discharge summaries of patients in groups 1 and 4. There was no statistically significant difference in age and gender distribution, size and location of PE, critical illness, smoking status, cardiovascular disease, trauma, and in-hospital mortality between patients in group 1 and 4. Patients in group 4 had a statistically significant increased prevalence of malignancy (67% vs. 40%, P = 0.046). Patients in group 4 also had a higher percentage of active cancer than those in group 1 (47% vs. 24%, P = 0.084), although not statistically significant. We defined active cancer as either a metastatic disease or a malignancy diagnosed shortly before or after the diagnosis of PE. Patients who were undergoing treatment for cancer at the time of diagnosis of PE were also considered to have active cancer. CONCLUSION We demonstrated a statistically significant increased prevalence of malignancy in patients with PE without DVT. However, pathophysiology and clinical significance are the aspects that remain to be understood after accrual of more patients and further research. Possibilities such as de novo thrombosis of pulmonary arteries, complete dislodgement of thrombi from peripheral veins, or false-negative venous duplex need to be explored.

Gray-scale median of the atherosclerotic plaque can predict success of lumen re-entry during subintimal femoral-popliteal angioplasty.

OBJECTIVE This study assessed whether the duplex ultrasound (DUS)-derived gray-scale median (GSM) of the most six distal portion of the occluded femoral-popliteal arterial segment can predict success of lumen re-entry for subintimal angioplasty. METHODS During the last 3 years, 108 patients (62% men) with a mean age of 73 +/- 10 years underwent 116 primary attempted DUS-guided subintimal angioplasties of the femoral-popliteal segment. Preprocedural B-mode DUS images of the plaque at the most distal occlusion segment were digitalized and normalized using Photoshop (Adobe, San Jose, Calif) software and standard criteria (gray level, 0 to 5 for lumen blood and 185 to 190 for the adventitia on a linear scale of 0 to 255). Overall GSM of the plaque segment about 2 cm long, immediately before the planned re-entry point to the true arterial lumen, was used for retrospective correlation with procedure success and other clinical indicators. RESULTS Mean plaque GSM for all cases was 22.5 +/- 12.6 (range, 3 to 60). The overall success rate of subintimal angioplasty procedures was 85%. Mean plaque GSM for 99 successful cases (18.4 +/- 7.8) was significantly lower than for 17 cases (46.4 +/- 8.1) where we failed (P < .0001). We failed in 90% of 19 cases with GSM >35, in 71% of 24 cases with GSM >20, and in 50% of 34 cases with GSM >25. There was no statistically significant difference (P = .45) between plaque GSM in 64 patients with diabetes (23.3 +/- 13.5) compared with 52 nondiabetic patients (21.5 +/- 11.4). Similarly, plaque GSM was not statistically different (P = .9) in 52 patients with renal insufficiency (22.7 +/- 13.2) compared with 64 patients with normal creatinine levels (22.4 +/- 12.2). At the 6-month follow-up, no statistically significant difference was found between mean GSM (17.8 +/- 7.8) in 47 stenosis-free cases compared with mean GSM (18 +/- 6.8) in 22 cases where severe restenosis (>70%) or reocclusion was identified by DUS scan (P = .4). CONCLUSIONS Plaque echogenicity represented by DUS-derived GSM can be used to predict the success of primary subintimal femoral-popliteal angioplasties.

Clinical Experience With Office-Based Duplex-Guided Balloon-Assisted Maturation of Arteriovenous Fistulas for Hemodialysis

BACKGROUND To examine the effect of office-based duplex-guided balloon-assisted maturation (DG-BAM) on arteriovenous fistula (AVF), we retrospectively analyzed our experience. METHODS Over the past 10 months, we performed 185 DG-BAMs (range, 1-8 procedures; mean, 3.7) in 45 patients (29 male, 16 female; mean age, 68.2 ± 12.8 years) with 31 radial-cephalic, 7 brachial-cephalic, and 7 brachial-basilic AVFs. Balloon sizes (3-10 mm) were chosen based on duplex measurements (1-2 mm larger than minimal vein diameter). Forearm AVFs were dilated to 8 mm, and arm AVFs were dilated to 10 mm. RESULTS All cases but one (99.5%) were successfully dilated. This exception was a large AVF rupture that required surgical repair. AVFs failed to mature in seven of the remaining 44 patients (16%) despite DG-BAM because of proximal vein stenoses (PVS). Four patients had cephalic arch stenoses, and three had proximal subclavian vein stenoses. Arm AVFs were more commonly associated with PVS (6 of 14 patients, 43%) as compared with the ones placed in the forearm (1 of 30 patients, 3.3%), with a P value of 0.0024. All these seven AVFs subsequently matured after successful balloon angioplasty of the venous outflow. CONCLUSIONS These data suggest that office-based DG-BAM of AVFs is feasible, safe, and averts nephrotoxic contrast and radiation. PVS appear to be the most common cause of failure for AVFs subjected to BAM. Because arm AVFs are at increased risk of PVS, we suggest that a careful duplex evaluation of the outflow be performed in these cases and in all AVFs that fail to mature.

Superior Vena Cava Perforation Following the Placement of a Superior Vena Cava Filter in Males Less than 60 Years of Age

Although the utility of the superior vena cava (SVC) filter remains controversial, the safety and efficacy of SVC filters in patients with upper extremity deep venous thrombosis in whom anticoagulation is contraindicated or ineffective have been well described. However, few complications have been reported. Herein we describe a series of three cases of SVC perforation in three young males following the placement of SVC filters. All three patients had deep venous thrombosis on upper extremity duplex ultrasonography and contraindication to anticoagulation (n = 1) or failure of anticoagulation (n = 2). Cardiac tamponade was demonstrated on transthoracic echocardiography in all three cases. The pericardial effusion was evacuated with either median sternotomy or pericardiocentesis in two cases. One of the patients died of cardiac arrest, and an autopsy showed aortic perforation in addition to the SVC perforation. This patient underwent chest compression following the cardiac arrest. One patient was lost to follow-up, and the other patient remained asymptomatic at the 1-year follow-up. This is the first case of SVC perforation that is associated with aortic perforation after the placement of an SVC filter. Owing to this occurrence, one has to be aware of these life-threatening complications when placing an SVC filter, especially in males less than 60 years of age.

Use of the StarClose device for closure of inadvertent subclavian artery punctures.

PURPOSE The placement of central catheters is a common procedure. It is also associated with multiple known complications. One of the potential complications that carry high morbidity and morality is arterial puncture and cannulation. Herein, we describe five case reports of a central line that was inadvertently placed in the subclavian artery and successfully removed using a StarClose device (Abbott Laboratories, Redwood CA). METHODS/RESULTS A retrospective chart review of a prospectively maintained database was performed. We identified five cases of inadvertent subclavian artery cannulation during central venous catheter placement. All catheters were removed successfully either in the operating room under fluoroscopic guidance or at the bedside with closure of the arteriotomy using the StarClose device. No cases required conversion to an open procedure for repair. No postremoval hematomas, bleeding episodes, myocardial infarctions, arrhythmias, or adverse clinical sequelae were identified. DISCUSSION Based on our limited experience, we feel that this method can be performed safely and expeditiously not only in the operating room but also at the bedside.

Full Metal Jacket Stenting of the Superficial Femoral Artery: A Retrospective Review

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.

Self-assessment of the training of vascular fellows: survey results of 219 vascular fellows from 2004 through 2007.

Introduction. In an attempt to identify the concerns of vascular fellows regarding their training in vascular surgery, we conducted a survey consisting of 22 questions at an annual national meeting from 2004 to 2007. Methods. The fellows were asked to assess various aspects of their training as excellent, satisfactory, or mixed. Results. 76% were satisfied with their endovascular experience during their fellowship while 82% were satisfied with their experience with open cases. The distribution of non-learning cases was felt to be excellent, satisfactory, or required some or much improvement in: 45%, 44%, 8%, and 2% respectively. However, only 61% felt that their vascular laboratory experience was excellent or satisfactory. Only 36% actually performed the vascular duplex exam, and only 49% felt that they would feel comfortable in managing a vascular laboratory. Conclusions. The results of this Survey suggest that several significant issues are reflected in the minds of vascular trainees.