Faculty Bibliography

INTRODUCTION: Extracranial carotid stenoses exhibit significant variance in embolic potential, with restenotic lesions having a particularly low propensity for embolization. This study sought to identify characteristics associated with increased generation of embolic debris during carotid angioplasty and stenting (CAS). METHODS: Captured particulate was available for analysis in 56 consecutive patients. Demographics were mean age, 74 years (range, 60-94 years); mean stenosis, 88% (range, 70%-99%); symptomatic, 27%; prior carotid endarterectomy (CEA), 27%; prior radiotherapy, 7%. Plaque echogenicity, heterogenicity, ulceration, and irregularity were assessed with B-mode duplex ultrasound analysis. Gray scale median (GSM) was calculated from normalized B-mode VHS video recordings. Calcification and degree of stenosis were determined angiographically. Captured particulate debris was evaluated for total number; number >200 microm, >500 microm, >1000 microm; mean and median size. Hematoxylin and eosin, trichrome, and von Kossa stains were used for histologic analysis of captured material. RESULTS: Restenotic carotid stenoses after prior CEA generated minimal embolic debris compared with primary stenoses. Four of 15 patients (27%) with restenotic lesions demonstrated embolic particles; all debris was <500 microm. All 41 patients with primary stenoses had some embolic debris; particulate size was >200 microm in 91%, >500 microm in 72%, and >1000 microm in 43%. In primary lesions, the number and size of captured particulate correlated with GSM and with the combined ultrasound findings of echogenicity, heterogenicity, and luminal irregularity/ulceration (P < .02, 95% confidence interval, 4.5-27.6). None of these ultrasound factors correlated independently with embolic particulate (P = NS). Patients aged >70 years exhibited more total particles (8.1 vs 2.3, P = .008) and increased mean particle size (370 vs 157 mum, P = .02). No significant correlation was observed between the number and size of captured embolic particulate and any other variable (stenosis percentage, prior radiotherapy, preprocedural symptoms, periprocedural symptoms, and calcification). Histologically, the embolic debris consisted of extensive amorphous, acellular proteinaceous material. Calcium debris in the embolic particulate was associated with heavily and moderately calcified lesions. CONCLUSIONS: Considerable variation exists in the number and size of embolic particles generated during CAS. Embolic potential is positively correlated with lesion GSM and the combination of lesion echogenicity, heterogenicity, and irregularity. Restenosis after prior CEA is associated with minimal embolic particulate generation, suggesting that embolic protection may not be necessary for CAS of restenotic lesions.

OBJECTIVES: Inadvertent subclavian artery catheterization during attempted central venous access is a well-known complication. Historically, these patients are managed with an open operative approach and repair under direct vision via an infraclavicular and/or supraclavicular incision. We describe our experience and technique for endovascular management of these injuries. METHODS: Twenty patients were identified with inadvertent iatrogenic subclavian artery cannulation. All cases were managed via an endovascular technique under local anesthesia. After correcting any coagulopathy, a 4-French glide catheter was percutaneously inserted into the ipsilateral brachial artery and placed in the proximal subclavian artery. Following an arteriogram and localization of the subclavian arterial insertion site, the subclavian catheter was removed and bimanual compression was performed on both sides of the clavicle around the puncture site for 20min. A second angiogram was performed, and if there was any extravasation, pressure was held for an additional 20min. If hemostasis was still not obtained, a stent graft was placed via the brachial access site to repair the arterial defect and control the bleeding. RESULTS: Two of the 20 patients required a stent graft for continued bleeding after compression. Both patients were well excluded after endovascular graft placement. Hemostasis was successfully obtained with bimanual compression over the puncture site in the remaining 18 patients. There were no resultant complications at either the subclavian or the brachial puncture site. DISCUSSION: This minimally invasive endovascular approach to iatrogenic subclavian artery injury is a safe alternative to blind removal with manual compression or direct open repair

BACKGROUND: Preoperative evaluation and perioperative management of cardiac disease in patients undergoing vascular surgery (VS) is important for patients and vascular surgeons. Recent evidence has emerged that has allowed us to develop contemporary paradigms for evaluating and managing coronary artery disease in VS patients perioperatively. METHODS: The utility of stress testing, the role of preoperative coronary revascularization, the optimal use of beta-blockers and statins, and the role of antiplatelet therapy in VS patients were reviewed in the literature. RESULTS: The revised Lee cardiac risk index, based on the number of risk factors (high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, insulin-dependent diabetes mellitus, renal failure, hypertension, and age >75) quantitates cardiac risk. Stress testing is not predictive of myocardial ischemia/infarction (MI) or death and is only recommended in patients with unstable angina or an active arrhythmia. Stress testing for patients with 0 to 2 risk factors delays VS up to 3 weeks. In high-risk patients (>or=3 risk factors), it helps to identify patients who may develop myocardial ischemia and would benefit from a 30-day period to optimize medical therapy before VS. Stress testing and coronary catheterization do not predict which coronary artery to revascularize to prevent MI or death. Revascularization does not decrease MI or death rates at 1 month or 6 years. Although beta-blocker treatment decreases cardiac risk with VS, timing and dosage (titration) influence outcomes, improper usage may increase stroke and death rate, and not all VS patients should be taking these drugs. Patients with >or=1 risk factor should be considered to begin a low dose beta-blocker 1 month before VS. Preoperative statin use sharply decreases MI, stroke, and death perioperatively and long-term postoperatively. CONCLUSION: Routine stress testing should not be performed before VS. The Lee index should be used to stratify risk in patients undergoing VS. Patients with >or=3 risk factors or active cardiac conditions should undergo stress testing, if VS can be delayed. All VS patients, except those with 0 risk factors, should be considered for a beta-blocker (bisoprolol, 2.5-5 mg/d started 1 month before VS, titrated to a pulse <70 beats/min and a systolic blood pressure >or=120 mm Hg). Intermediate risk factors may not require aggressive heart rate control but simply maintenance on a low-dose beta-blocker. Statins should be started (ideally 30 days) before all VS using long-acting formulations such as fluvastatin (80 mg/d) for patients unable to take oral medication

INTRODUCTION: Prior neck irradiation may induce atherosclerosis in the carotid artery and is considered an indication for carotid angioplasty and stenting (CAS). This study sought to evaluate the effect of neck radiation therapy (XRT) on the rate of restenosis and embolic potential in patients undergoing CAS. METHODS: Two hundred ten CAS procedures were performed on 193 patients (XRT [N = 28], non-XRT [N = 182]). Mean follow-up was 347 +/- 339 days (median, 305 days; range, 16-1354 days). Duplex velocity criteria for restenosis after CAS were: >50% restenosis (peak systolic velocity [PSV] > 125 cm/sec, end diastolic velocity [EDV] 40-99 cm/sec, and internal carotid artery to common carotid artery systolic ratio [ICA/CCA] > 2.0); >70% restenosis (PSV>230 cm/sec, EDV>100 cm/sec, and ICA/CCA ratio >4.0). Restenosis >70% was confirmed by digital subtraction angiography. Additional endpoints included groin hematoma, groin pseudoaneurysm, myocardial infarction, stroke, mortality, and the combined myocardial infarction/stroke/mortality rate. Captured particulate data was obtained from microporous filters used during CAS. Nineteen XRT and 128 non-XRT consecutive filters were analyzed. Photomicroscopy was performed along three axes for each filter, and the quantity and size of the captured particles were analyzed using video image analysis software. RESULTS: There were more men (XRT: 85.7% vs. non-XRT: 52.8%, P < .001) and prior surgical neck dissections in the XRT patients (XRT: 82.1% vs. non-XRT: 4.7%, P < .001). Pre-procedural stenosis did not differ significantly betweeen the two groups (XRT: 86.5% +/- 8.9% [range, 70%-99%] vs. non-XRT: 85.5% +/- 8.7% [range 70%-99%], P = NS). Perioperative outcomes, including the composite 30 day stroke/myocardial infarction/mortality rate did not differ significantly between the two groups (XRT: 0% vs. non-XRT: 3.2%, P = NS). Twelve-month freedom from restenosis rates did not differ significantly at the 50% threshold (XRT: 95.5% vs. non-XRT: 90.3%, P = NS) or at the 70% threshold (XRT: 95.5% vs. non-XRT: 96.5%, P = NS). Target lesion revascularization did not differ significantly (XRT: 0% vs. non-XRT: 0.5%, P = NS). Photomicroscopy demonstrated a trend towards increased particle number and size in the XRT filters, however the results did not achieve statistical significance: particle number (XRT: 9.8 +/- 8.4 vs. non-XRT: 9.6 +/- 11.7, P = NS), %patients with particle size >1000 microm (XRT: 47.4% vs. non-XRT: 30.5%, P = NS). CONCLUSIONS: This study suggests that the durability of CAS and the characteristics of captured embolic particles are not altered by a history of neck XRT. This supports the safety and efficacy of CAS for the treatment of patients with a history of neck XRT. Prior neck XRT may predispose the patient to the de novo development of stenoses at locations that were not previously treated

BACKGROUND: Case and single center reports have documented the feasibility and suggested the effectiveness of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs), but the role and value of such treatment remain controversial. OBJECTIVE: To clarify these we examined a collected experience with use of EVAR for RAAA treatment from 49 centers. METHODS: Data were obtained by questionnaires from these centers, updated from 13 centers committed to EVAR treatment whenever possible and included treatment details from a single center and information on 1037 patients treated by EVAR and 763 patients treated by open repair (OR). RESULTS: Overall 30-day mortality after EVAR in 1037 patients was 21.2%. Centers performing EVAR for RAAAs whenever possible did so in 28% to 79% (mean 49.1%) of their patients, had a 30-day mortality of 19.7% (range: 0%-32%) for 680 EVAR patients and 36.3% (range: 8%-53%) for 763 OR patients (P < 0.0001). Supraceliac aortic balloon control was obtained in 19.1% +/- 12.0% (+/-SD) of 680 EVAR patients. Abdominal compartment syndrome was treated by some form of decompression in 12.2% +/- 8.3% (+/-SD) of these EVAR patients. CONCLUSION: These results indicate that EVAR has a lower procedural mortality at 30 days than OR in at least some patients and that EVAR is better than OR for treating RAAA patients provided they have favorable anatomy; adequate skills, facilities, and protocols are available; and optimal strategies, techniques, and adjuncts are employed

Improvements in the design of endovascular grafts are based on lessons learned from difficulties encountered with prior-generation devices. The most common difficulties in device design relate to how the device is delivered and how it can safely and durably fix the aneurysm. This concept is especially true in patients with difficult anatomy. Difficult anatomy, such as small, calcified, tortuous access vessels and short angulated sealing zones, continue to challenge engineers. Currently, the US Food and Drug Administration has approved eight endovascular devices for the treatment of aortic aneurysms: five for abdominal aortic aneurysms and three for thoracic aortic aneurysms. Compared to the first-generation devices approved in 1999, current devices have smaller and more flexible delivery systems. The devices themselves are more flexible and have better fixation than prior-generation devices. This article will focus on the next generation of devices that are not yet approved, but currently under investigation in the United States

We reviewed our experience with urgent carotid intervention in the setting of acute neurological deficits. Between June 1992 and August 2008, a total of 3145 carotid endarterectomies (CEA) were performed. Twenty-seven patients (<1.0%) were categorized as urgent. The mean age was 74.1 years (range 56-93 years) with 16 (60%) men, and 11 (40%) women, Symptoms included extremity weakness or paralysis (n = 13), amaurosis fugax (n = 6), speech difficulty (n = 2), and syncope, (n = 3). Three patients exhibited a combination of these symptoms. Three open thrombectomy were performed. Regional anesthesia was used in 13 patients (52%). Seventeen patients (67%), required shunt placement. At 30-days, 2 patient (7%) suffered a stroke, and 1 (4%) died. Urgent CEA can be performed safely. A stroke rate of 7% is acceptable in those who may otherwise suffer a dismal outcome without intervention

In patients who require lower extremity revascularization, prosthetic graft is a reasonable alternative in the absence of a suitable autologous vein conduit. However, prosthetic bypass grafts have limited patency, especially for infrageniculate reconstruction. Polytetrafluoroethylene grafts were geometrically modified at the distal end to increase their patency. The authors reviewed their experience with the Distaflo graft in patients who required lower extremity below-knee popliteal and tibial bypasses when no suitable autologous vein conduit was available. Chart review was conducted of the 57 patients who underwent 60 lower extremity bypasses over a 3-year period between June 2003 and April 2006. Twenty-four revascularizations were constructed to the tibial outflow sites, whereas the remaining grafts were placed to the below-knee (28) and above-knee (8) popliteal artery, respectively. Study endpoints were primary, assisted primary, secondary patency, and limb salvage at the time of follow-up. Distaflo bypass was performed at the infrageniculate level in 86.7% of cases (28 below-knee popliteal, 24 tibial). Mean follow-up time was 12 months (range, 0.5-37.5 months). At 1 year, primary, assisted primary, and secondary patencies and limb salvage rates for below-knee popliteal bypasses were 83.5%, 89.5%, 94.7%, and 94.4%, respectively. Primary, assisted primary, and secondary patencies and limb salvage rates for tibial bypasses were 44.4%, 44.4%, 63.2%, and 74.9%, respectively. Distaflo precuffed graft is a good alternative conduit for below-knee popliteal and tibial lower extremity reconstructions in the absence of an autologous vein and appears to have promising early patency and limb salvage rates even when used for tibial bypasses

Recent reviews of device-specific complications using neuroprotection have addressed technical difficulties during delivery as well as adverse outcomes, intraoperative and 30-day. Little has been written, however, regarding the relevance of filter occlusion during the carotid stent procedure. A retrospective review was conducted of patients undergoing carotid artery stent procedures using a variety of neuroprotection devices from 2003 to 2007. Prospective databases from two institutions were examined for incidence and management of filter occlusions during procedures as well as adverse neurological events (intraoperative and 30-day) associated with filter occlusion. There were 283 carotid artery stent procedures performed on 256 patients (163 male, 93 female): 177 (62.5%) arteries were asymptomatic and 106 were symptomatic. Neurological adverse events occurred in six patients (2.1%); three of these resolved completely at 72 hr. Neuroprotection was used in 95% of all patients, and filters were used in 221 stent procedures: Boston Scientific Filter Wire (n = 81), Guidant Accunet (n = 100), Angioguard (n = 17), and Abbot Emboshield (n = 23). Filter occlusion occurred in 11 patients (4.9%) in whom this form of neuroprotection was employed: Angioguard (n = 5), Accunet (n = 2), Emboshield (n = 2), and EPI Filter wire (n = 2). Two of the 11 patients with filter occlusions suffered a neurological event. There was no correlation between filter occlusion and gender, symptoms, stent, or filter type (p > 0.05). Filter occlusion was managed with export catheter-directed aspiration in seven patients and with prompt filter retrieval in five patients. Filter occlusion is an infrequent event that does not appear to be filter-specific and can be managed successfully by catheter-directed aspiration or filter retrieval. The majority of patients with filter occlusion do not suffer from atheroemboli as a result of this occlusion