Dynamic Perioperative Platelet Activity and Cardiovascular Events in Peripheral Artery Disease.

OBJECTIVE: Patients with peripheral artery disease (PAD) undergo lower extremity revascularization (LER) for symptomatic relief or limb salvage. Despite LER, patients remain at increased risk of platelet-mediated complications, such as major adverse cardiac and limb events (MACLE). Platelet activity is associated with cardiovascular events; yet little is known about the dynamic nature of platelet activity over time. We therefore investigated the change in platelet activity over time and its association with long-term cardiovascular risk. METHODS: Patients with PAD undergoing LER were enrolled into the multicenter, prospective Platelet Activity and Cardiovascular Events (PACE) study. Platelet aggregation was assessed by light transmission aggregometry (LTA) to submaximal epinephrine (0.4µ M) immediately prior to LER, and on post-operative day 1 or 2 (POD1) and 30 (POD30). A hyperreactive platelet phenotype was defined as >60% aggregation. Patients were followed longitudinally for MACLE, defined as the composite of death, myocardial infarction, stroke, major lower extremity amputation, or acute limb ischemia leading to reintervention. RESULTS: Among 287 patients undergoing LER, mean age was 70 ± 11 years, 33% were female, 61% were white, and 89% were on baseline antiplatelet therapy. Platelet aggregation to submaximal epinephrine induced a bimodal response; 15.5%, 16.8%, and 16.4% of patients demonstrated a hyperreactive platelet phenotype at baseline, POD1, and POD30, respectively. Platelet aggregation increased by 18.5% (P=0.001) from baseline to POD1, which subsequently returned to baseline at POD30. After a median follow-up of 19 months, MACLE occurred in 165 (57%) patients. After adjustment for demographics, clinical risk factors, procedure type, and antiplatelet therapy, platelet hyperreactivity at POD1 was associated with a significant hazard of long-term MACLE (aHR 4.61, 95% CI 2.08-10.20, P<0.001). CONCLUSION: Among patients with severe PAD, platelet activity increases following LER. Platelet hyperreactivity to submaximal epinephrine on POD1 is associated with long-term MACLE. Platelet activity following LER may represent a modifiable biomarker associated with excess cardiovascular risk.

The Effect of Ipsilateral Carotid Revascularization on Contralateral Carotid Duplex Parameters in Patients with Bilateral Carotid Stenosis.

BACKGROUND: Duplex-derived velocity measurements are often used to determine the need for carotid revascularization. There is evidence that severe ipsilateral carotid stenosis can cause artificially elevated velocities in the contralateral carotid artery, which may decrease following ipsilateral revascularization. The objective of this study was to determine if contralateral carotid artery duplex velocities decrease following ipsilateral carotid endarterectomy or stenting procedures. METHODS: This is a single institutional retrospective study of prospectively collected data on all patients who underwent carotid revascularization from 2013 to 2021. Patients with immediate preoperative and first postoperative Duplex scan within 4 months of carotid revascularization at our vascular laboratory were included for analysis. Patients with contralateral occlusion were excluded. Duplex criteria used to define moderate (50-69%) and severe (>70%) stenosis were systolic velocity ≥125 cm/sec and ≥230 cm/sec, respectively. RESULTS: Between 2013 and 2021, 129 patients with bilateral carotid stenosis underwent either carotid endarterectomy (98) or a stenting procedure (31). The majority of patients (90%) underwent intervention for severe stenosis. Preoperatively, the contralateral artery was categorized as severe in 30.4% patients. After ipsilateral carotid revascularization, 86 patients (67.2%) saw a decrease in the contralateral artery peak systolic velocity (PSV), while the remaining remained stable or increased. Fifty-four patients had a change in designated stenosis severity in the contralateral artery. Between the carotid endarterectomy and stenting cohorts, there was no significant difference in the proportion of patients whose contralateral velocity decreased (69.4% vs. 61.3%, P = 0.402). Patients with coronary artery disease and diabetes were significantly less likely to experience a decrease in the contralateral artery PSV after ipsilateral intervention (P = 0.018 and P = 0.033). CONCLUSIONS: In patients with bilateral carotid disease, ipsilateral revascularization can change the contralateral artery velocity and perceived disease severity. Most patients were noted to have a decrease in the contralateral artery PSV, although almost one-third either stayed stable or increased. On multivariable analysis, patients with coronary artery disease and diabetes were less likely to see a decrease in the contralateral artery PSV after intervention. Patients who are at risk for artificial elevation of the contralateral artery may warrant a re-evaluation of the contralateral artery after ipsilateral intervention. These patients are potentially better assessed with axial imaging, although further research is needed.

Periprocedural P2Y12 inhibitors improve perioperative outcomes after carotid stenting by primarily decreasing strokes.

OBJECTIVE: The continuation of antiplatelet agents in the periprocedural period around carotid stenting (CAS) procedures is felt to be mandatory to minimize the risk of periprocedural stroke. However, the optimal antiplatelet regimen is unclear, with some advocating dual antiplatelet therapy, and others supporting the use of P2Y12 inhibitors alone. The objective of this study was to evaluate the periprocedural effect of P2Y12 inhibitors for CAS. METHODS: The Vascular Quality Initiative was used from years 2007 to 2020. All transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TF-CAS) procedures were included. Patients were stratified based on perioperative use of P2Y12 inhibitors as well as symptomatic status. Primary end points were perioperative neurological events (strokes and transient ischemic attacks). Secondary end points were mortality and myocardial infarction. RESULTS: A total of 31,036 CAS procedures were included for analysis, with 49.8% TCAR and 50.2% TF-CAS cases; 63.8% of patients were male and 82.3% of patients were on a P2Y12 inhibitor. P2Y12 inhibitor use was more common in males, asymptomatic patients, those older than 70 years, and concurrent statin use. P2Y12 inhibitors were more likely to be used in TCAR cases than in TF-CAS cases (87.3% vs 76.8%; P < .001). The rate of periprocedural neurological events in the whole cohort was 2.6%. Patients on P2Y12 inhibitors were significantly less likely to experience a periprocedural neurological event (2.3% vs 3.9%; P < .001) and mortality (0.6% vs 2.1%; P < .001) than those who were not on a P2Y12 inhibitor. There was no effect on the rates of myocardial infarction. On multivariate analysis, both symptomatic and asymptomatic patients on P2Y12 inhibitors were significantly less likely to develop perioperative neurological events. Additionally, the use of P2Y12 inhibitors demonstrated an independent significant effect in reducing of the rate of perioperative stroke (odds ratio, 0.29; 95% confidence interval, 0.25-0.33). Finally, additional analysis of the types of P2Y12 inhibitors used revealed that all seemed to be equally effective in decreasing the periprocedural neurological event rate. CONCLUSIONS: The use of perioperative P2Y12 inhibitors seems to markedly decrease the perioperative neurological event rate with TCAR and TF-CAS in both symptomatic and asymptomatic patients and should be strongly considered. Patients with contraindications to P2Y12 inhibitors may not be appropriate candidates for any CAS procedure. Additionally, alternative types of P2Y12 inhibitors seem to be equally effective as clopidogrel. Finally, an analysis of the Vascular Quality Initiative demonstrates that, even for TCAR cases, only 87.3% of patients seem to be on P2Y12 inhibitors in the periprocedural period, leaving room for significant improvement.

Response to clopidogrel in patients undergoing lower extremity revascularization.

OBJECTIVES: Clopidogrel is effective at decreasing cardiovascular events in patients with peripheral artery disease (PAD); however, its effect on limb outcomes are less known. This study investigated the variability in response to clopidogrel and its relationship with clinical limb outcomes. METHODS: Three hundred subjects were enrolled in the Platelet Activity and Cardiovascular Events (PACE) study prior to lower extremity revascularization, of whom 104 were on clopidogrel. Light transmission platelet aggregation was measured in response to ADP 2 µm immediately prior to revascularization. Patients were followed longitudinally for a median follow-up of 18 months. The primary endpoint was major adverse limb events (MALE) defined by major amputation or reoperation of the affected limb. Patients were stratified into groups according to percent ADP-induced aggregation. Poor response to clopidogrel was defined by >50% aggregation. RESULTS: Overall, the median age was 70 (63, 76) and 35.6% were female. Twenty-nine (27.9%) patients experienced MALE during their follow-up. Median aggregation to ADP 2 µ m was 22.5% (Q1-Q3: 10%, 50%) and 27 subjects (26%) were clopidogrel poor responders. Baseline aggregation was higher in subjects who went on to develop a MALE than those without MALE (43% vs 20%, p = .017). Subjects with aggregation > median (22.5%) were more likely to experience MALE than aggregation < median (38.5% vs 17.3%, p = .029). After multivariable adjustment for age, sex, race/ethnicity, BMI, diabetes, coronary artery disease, and aspirin use, aggregation > median was associated with MALE (adjusted HR [aHR] 2.67, 95% CI 1.18-6.01, p = .018). When stratified by established cut-offs for responsiveness to clopidogrel (50% aggregation), poor responders were more likely to experience MALE than normal responders (44.4% vs 22.1%, aHR 2.18, 95% CI 1.00-4.78, p = .051). CONCLUSIONS: Among patients undergoing lower extremity revascularization on clopidogrel, higher baseline percent aggregation is associated with increased risk for major adverse limb events.

Risk Factors for and Intraoperative Management of Intolerance to Flow Reversal in TCAR.

BACKGROUND: In patients deemed high risk for carotid endarterectomy (CEA) who are indicated for treatment of carotid artery stenosis (CAS), transcarotid artery revascularization (TCAR) has been demonstrated as a safe and effective alternative to trans-femoral carotid artery stenting (TF-CAS). Compared to CEA, where approx. 12% of patients undergoing awake intervention do not tolerate internal carotid artery (ICA) clamping, only 1-2% of patients were observed to have intolerance to flow reversal during TCAR based on data from the ROADSTER1/2 trials. This study reviewed awake interventions from those trials to assess factors associated with intolerance to flow reversal and review how those cases were managed. METHODS: This is a retrospective review of prospectively collected data from Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial along with the subsequent post-approval (ROADSTER-2) trial. The subset of patients from both trials undergoing awake TCAR was analyzed to compare demographics, procedural details, and anatomic factors between patients who did and did not experience intolerance to reversal of flow to assess for predisposing factors. Patients were deemed intolerant to flow reversal at the discretion of the operator, often related to changes in completion of neurologic tasks, hemodynamic stability, or patient reported symptoms. RESULTS: A total of 103 patients from ROADSTER and 194 patients from ROADSTER-2 underwent TCAR under local/regional anesthesia. Of these, 8 patients had intolerance to flow reversal, though all cases were successfully completed. While intraoperative hemodynamic data was only available for 5 of the 8 intolerant patients, none experienced hypotension. 4 cases were completed under low flow reversal, 3 cases were successfully weaned from low to high flow over several minutes, and 1 case required general anesthesia. No significant association was found between intolerance to flow reversal and comorbidities including diabetes mellitus (DM), hypertension (HTN), hyperlipidemia (HLD), congestive heart failure (CHF), prior MI or angina, pre-op CAS-related symptoms, prior stroke, prior CAS or CEA, prior neck radiation, tandem stenosis, high cervical stenosis, or hostile neck. A trend towards significance was seen with chronic obstructive pulmonary disease (COPD) and contralateral carotid artery occlusion (P = 0.086 and 0.139, respectively). CONCLUSIONS: Despite intolerance to flow reversal, TCAR cases were successfully completed by adjusting reversal-of-flow rate and do not typically require conversion to GETA. While factors contributing to intolerance of flow reversal during TCAR remain poorly understood, this study identified a trend towards significance with an association of preexisting COPD and contralateral carotid artery occlusion. Given the low number of patients who experienced this issue, a larger sample size is required to better elucidate these trends.

Endovascular treatment of popliteal artery aneurysms has comparable long-term outcomes to open repair with shorter lengths of stay.

OBJECTIVE: During the past two decades, the treatment of popliteal artery aneurysms (PAAs) has undergone a transformation. Although open surgical repair (OR) has remained the reference standard for treatment, endovascular repair (ER) has become an attractive alternative for select patient populations. The objective of the present study was to compare the outcomes of OR vs ER of PAAs at a single institution. METHODS: We performed a retrospective review of the medical records for all patients who had undergone repair for PAAs from 1998 to 2017. The baseline patient, anatomic, and operative characteristics and outcomes were compared between the OR and ER cohorts. Intervention and treatment were at the discretion of the surgeon. RESULTS: From 1998 to 2017, 64 patients had undergone repair of 73 PAAs at our tertiary care center. Of the 69 patients (73 PAAs), 29 (33 PAAs) had undergone OR and 35 (40 PAAs) had undergone ER. When comparing the two cohorts, no statistically significant differences were found in the demographic characteristics such as age, gender, or number of runoff vessels. Significantly more patients in the ER group (n = 21; 53%) than in the OR group (n = 7; 21%) had had hyperlipidemia (P = .008) and a previous carotid intervention (6% vs 0%; P = .029). Overall, the presence of symptoms was similar between the two groups. However, the OR group had a significantly higher number of patients who had presented with acute ischemia (P = .01). The length of stay was significantly shorter for the ER cohort (mean, 1.8 days; range, 1-11 days) than for the OR group (mean, 5.4 days; range, 2-13 days; P < .0001). No significant difference was found in the primary or secondary patency rates between the two groups. In the ER group, good runoff (two or more vessels) was a positive predictor for primary patency at 1 year (odds ratio, 3.36; 95% confidence interval, 1.0-11.25). However, it was not in the OR group. Postoperative single and/or dual antiplatelet therapy did not affect primary patency in either cohort. CONCLUSIONS: The results of our study have demonstrated that ER of PAAs is a safe and durable option with patency rates comparable to those with OR and a decreased length of stay, with good runoff a positive predictor for primary patency in the ER cohort.

Low-frequency avoidable errors during transcarotid artery revascularization.

OBJECTIVE: Transcarotid artery revascularization (TCAR) seems to be a safe and effective alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). The TCAR system represents a paradigm shift in the management of carotid artery stenosis with potential for a significant decrease in periprocedural morbidity. However, as with CEA or TF-CAS, TCAR is associated with infrequent complications related to user technical error, most of which are preventable. Our goal is to describe these low-frequency events, and to provide guidelines for avoiding them. METHODS: The U.S. Food and Drug Administration (FDA) requires that all medical device manufacturers create a system for receiving, reviewing, and evaluating complaints (Code 21 of Federal Regulations 820.198). Silk Road Medical, Inc (Sunnyvale, Calif), has established a process by which all feedback, including complaints that may not meet FDA criteria, is captured and stored in a database for detailed analysis. More than 13,300 cases have been performed; submitted complaints were reviewed for incidents of serious injury and periprocedural complications, above and beyond the device-related events that must be reported to the FDA. RESULTS: A total of 13,334 patients have undergone TCAR worldwide between early 2011 and December 2019 using the SilkRoad device. Reported complications included 173 dissections (1.4% overall rate) of the common carotid artery at the access point, of which 22.5% were managed without intervention or with medical therapy alone and 24.3% were converted to CEA (considered failing safely). Errors in the location of stent deployment occurred in 16 cases (0.13%), with the most common site being the external carotid artery (75%). One wrong side carotid artery stent was placed in a patient with a high midline pattern of the bovine arch. Cranial nerve injury was reported in 11 cases (0.08%), only one of which persisted beyond 3 months. There have been three reported pneumothoraces and one reported chylothorax. Many of these errors can be recognized and prevented with careful attention to detail. CONCLUSIONS: In high-risk patients requiring treatment for carotid artery stenosis, TCAR has been proven as an alternative to TF-CAS with an excellent safety profile. As with CEA or TF-CAS, this procedure has the potential for infrequent complications, often as a result of user technical error. Although significant, these events can be avoided through a review of the collective experience to date and recognition of potential pitfalls, as we have described.

Management of inferior vena cava thrombosis with the FlowTriever and ClotTriever systems.

OBJECTIVE: Although inferior vena cava (IVC) thrombosis is infrequently encountered, it carries a significant risk of post-thrombotic syndrome and pulmonary embolus. Recent studies show no difference in the incidence of post-thrombotic syndrome in patients with iliofemoral deep venous thrombosis (DVT) treated with pharmacothrombolysis vs anticoagulation alone; however, there is an associated increased risk of bleeding. The treatment of IVC thrombosis is less well-studied and the hemodynamic changes may be more significant with pharmacothrombolysis, although the bleeding risk remains. The ClotTriever and FlowTriever systems remove thrombus from veins without the use of thrombolytics. Our study evaluates outcomes of patients undergoing mechanical thrombectomy for the treatment of IVC thrombosis using the ClotTriever and FlowTriever devices. METHODS: A retrospective chart review was performed to identify consecutive patients who underwent mechanical thrombectomy for the treatment of IVC thrombosis using the ClotTriever and/or FlowTriever systems from November 2018 to January 2020 at four data-sharing institutions. The decision of which device(s) to use was at the discretion of the surgeon. Patient demographics, symptomatology, and imaging characteristics were captured at presentation and follow-up. RESULTS: A total of 15 patients met the inclusion criteria; 10 were male, and the average age was 59 years. The majority of patients were symptomatic at presentation (n = 14), had a prior history of DVT (n = 13), and had a preexisting IVC filter (n = 8). Eleven patients presented with acute onset (<1 week) of symptoms, whereas three patients had subacute (1-4 weeks) symptoms. Most patients had an associated iliofemoral DVT (n = 13) and were treated with both ClotTriever and FlowTriever (n = 8); others were treated with either ClotTriever or FlowTriever alone (n = 5 and n = 2, respectively). Technical success was achieved in all but two patients, one who had a nonocclusive thrombus densely adherent to a preexisting IVC filter and another who had a chronic rubbery clot in the IVC that could not be cleared. No patient required concomitant lytic therapy or a postoperative stay in the intensive care unit. Furthermore, there were no postoperative bleeding events, myocardial infarctions, pulmonary emboli, renal impairments, or deaths. The median length of stay was 3 days (range, 1-37 days). Patients underwent postoperative follow-up (n = 7) as well as extended follow-up (>6 months; n = 8). All patients who achieved technical success were asymptomatic without evidence of reocclusion of the IVC on follow-up imaging. CONCLUSIONS: In our multicenter series of 15 patients, The ClotTriever and FlowTriever showed promise in the treatment of IVC thrombosis without the use of fibrinolytic drugs, with no bleeding events and no requirement for intensive care unit stay.

Endovascular Treatment of Nutcracker Syndrome.

BACKGROUND: Nutcracker syndrome, or mesoaortic compression of the left renal vein (LRV), with associated symptoms related to venous hypertension in the left kidney, is a rare entity that may result in severe symptoms requiring operative intervention. We report on 3 patients who presented with nutcracker syndrome, including one patient with a circumaortic LRV resulting in posterior nutcracker syndrome, who underwent successful endovascular treatment with renal vein stenting. A review of existing literature on endovascular management of nutcracker syndrome follows. METHODS: Three women (age range 28-43 years) presented with symptoms and imaging studies consistent with nutcracker syndrome. Symptoms included pelvic and flank pain in all 3 patients, and episodes of hematuria in 2 patients. Imaging studies demonstrated compression of the LRV between the superior mesenteric artery and aorta in 2 of the patients. The third patient was noted to have a circumaortic LRV. RESULTS: All 3 patients underwent venography and LRV stenting. Stents included a 12 × 40 mm self-expanding nitinol stent, 14 × 60 mm WALLSTENT, and 16 × 40 mm WALLSTENT. All patients were placed on clopidogrel postoperatively. The duration of follow-up ranged from 6 to 27 months. At follow-up, all 3 patients reported significant symptomatic improvement, and duplex ultrasonography demonstrated stent patency in all. CONCLUSIONS: Nutcracker syndrome is a rare condition that can be successfully treated with renal vein stenting via an endovascular approach. Results are encouraging at follow-up periods beyond 2 years.

Endovascular solutions to arterial injury due to posterior spine surgery.

Iatrogenic arterial injury is an uncommon but recognized complication of posterior spinal surgery. The spectrum of injuries includes vessel perforation leading to hemorrhage, delayed pseudoaneurysm formation, and threatened perforation by screw impingement on arterial vessels. Repair of these injuries traditionally involved open direct vessel repair or graft placement, which can be associated with significant morbidity. We identified five patients with iatrogenic arterial injury during or after posterior spinal surgery between July 2004 and August 2009 and describe their endovascular treatment. Intraoperative arterial bleeding was encountered in two patients during posterior spinal surgery. The posterior wounds were packed, temporarily closed, and the patient was placed supine. In both patients, angiography demonstrated arterial injury necessitating repair. Covered stent grafts were deployed through femoral cutdowns to exclude the areas of injury. In three additional patients, postoperative computed tomography imaging demonstrated pedicle screws abutting/penetrating the thoracic or abdominal aorta. Angiography or intravascular ultrasound imaging, or both, confirmed indention/perforation of the aorta by the screw. Aortic stent graft cuffs were deployed through femoral cutdowns to cover the area of aortic contact before hardware removal. All five patients did well and were discharged home in good condition. Endovascular repair of arterial injuries occurring during posterior spinal procedures is feasible and can offer a safe and less invasive alternative to open repair.

Update on endovenous laser ablation: 2011.

In 2001, the use of endovenous laser ablation (EVLA) was introduced to the United States to treat superficial venous insufficiency. EVLA has subsequently undergone a rapid rise in popularity and usage with a concomitant decrease in traditional operative saphenectomy. Since its inception, the use of EVLA to treat superficial venous insufficiency has advanced significantly. The efficacy of treatment has been validated using both hemoglobin-specific laser wavelength and water-specific laser wavelength lasers. Currently, laser optimization is focusing on reducing postprocedural sequelae. The clinical parameters that correlate best with improved postoperative recovery use lower power/energy settings, water-specific laser wavelength lasers, and jacket or radial-emitting tips. Future study is still required to assess the durability of treatment at lower power and energy settings coupled with jacket or radial-emitting tip fibers. Long-term follow-up using duplex imaging is recommended to ensure persistent treatment success.

Cystic adventitial disease of the popliteal artery: is there a consensus in management?

Cystic adventitial disease (CAD) is a well described disease entity that commonly affects the popliteal artery, presenting as a rare cause of non-atherosclerotic claudication. The traditional surgical approaches are cyst resection and bypass, or cyst evacuation or aspiration. We report the case of a 58-year-old female with CAD of the popliteal artery treated successfully with cyst resection and bypass using an autologous graft. We reviewed the literature over the last 25 years on management and outcomes of CAD of the popliteal artery. We identified a total of 123 cases; most cases were treated using a traditional repair, while 3 cases used an endovascular approach. The overall success rate using bypass was 93.3%, compared to 85% in the evacuation/aspiration cohort. All cases treated endovascularly resulted in failure. While no consensus exists regarding the preferred modality to treat CAD, we believe that resection of the cyst and bypass affords the best outcomes.

Improved hemodynamic outcomes with glycopyrrolate over atropine in carotid angioplasty and stenting.

OBJECTIVE: Prophylactic atropine traditionally has been used to prevent CAS-associated hemodynamic depression. Glycopyrrolate may serve as an alternative with decreased cardiac effects. This study aims to compare the efficacy of prophylactic glycopyrrolate to atropine in preventing CAS-induced hemodynamic instability and cardiac complications. METHODS: 115 consecutive CAS patients from 2004-2010 were evaluated. Primary endpoints were stroke, MI, bradycardia (HR<60 beats/min), and hypotension (systolic BP <90 mm Hg). Additional outcomes included tachycardia (HR >100 beats/min), hypertension (systolic BP >160 mm Hg), pre- and postoperative systolic BP difference, vasopressor use, arrhythmias, cardiac enzyme elevations, and access site complications. RESULTS: Of 115 patients, 65 (56.5%) patients who received atropine or glycopyrrolate prior to CAS were analyzed [40 (61.5%) patients received glycopyrrolate, 25 (38.5%) received atropine]. Mean age was 70.0 ± 8.5 years (range, 48-86 years). Mean stenosis was 86.2 ± 7.4% (range, 70-99%). No MI, major stroke, or death was observed in the 30-day postoperative period. Baseline systolic BP and HR were equivalent between groups. Postoperative bradycardia and hypotension were significantly lower in glycopyrrolate patients compared with atropine patients (30% vs 72%, P = .002; 2.5% vs 36%, P < .001, respectively). Postoperative hypertension was also significantly lower in the glycopyrrolate cohort (2.5% vs 16%, P = .047), whereas tachycardia, pressure changes, vasopressor use, and cardiac complications did not differ significantly. No significant differences in neurologic and access site complications were observed. CONCLUSIONS: Prophylactic glycopyrrolate, compared with atropine, reduces hemodynamic instability during CAS. The authors recommend glycopyrrolate use to prevent CAS-induced bradycardia and hypotension.

Intermediate-term EVAR outcomes in octogenarians.

OBJECTIVE: The utilization of endovascular abdominal aortic aneurysm repair (EVAR) in suitable patients has resulted in decreased perioperative morbidity and mortality. Octogenarians as a subgroup have been more readily offered EVAR, as it is less invasive, and therefore presumably better tolerated than conventional open aortic repair. The purpose of this study is to investigate periprocedural and late EVAR outcomes in octogenarians compared with patients less than 80 years of age. METHODS: From January 2003 to May 2008, 322 patients underwent EVAR. A total of 117 octogenarians were compared with 205 patients less than 80 years of age. A retrospective review of the demographic data, aneurysm details, perioperative morbidity, mortality, and late outcomes were analyzed. RESULTS: Octogenarians were significantly more likely to have a history of diabetes mellitus (51% vs 23%; P < .001), coronary artery disease (45% vs 32%; P = .0165), chronic obstructive pulmonary disease (44% vs 30%; P = .0113), and renal insufficiency (57% vs 31%; P < .0001). There were no significant differences in the rates of perioperative myocardial infarction, stroke, death, intestinal, or arterial ischemic complications between the two groups. Octogenarians had a significant higher rate of pulmonary complications (5.1% vs 1%; P < .03) and access-site hematomas (12% vs 2.4%; P = .001) than younger patients. When all significant perioperative morbidity was combined, octogenarians were twice as likely to develop complications following EVAR than younger patients (27.4% vs 11.7%; P = .001). At 5-year follow-up, younger patients were twice as likely to develop type II endoleaks. CONCLUSIONS: EVAR can be performed safely and effectively in octogenarians, and the incidence of major complications including myocardial infarction, stroke, and death is unchanged compared with younger patients. However, there is a significantly increased rate of access-site hematomas, pulmonary, and perioperative complications in octogenarians as a whole. Our findings suggest EVAR remains a suitable form of therapy in the elderly group provided there is an appropriate preoperative evaluation and perioperative monitoring following repair.

Endovascular treatment of spontaneous dissections of the superior mesenteric artery.

BACKGROUND: Spontaneous dissection of the superior mesenteric artery (SMA) is exceedingly rare. Treatment options range from observation to anticoagulation to open surgery or endovascular repair. We present our experience to date in the management of isolated SMA dissections. METHODS: A retrospective review of the vascular surgery and radiology databases from 1998 to 2008 was performed. In general, incidental radiologic findings of a dissection were managed expectantly. The decision to intervene was based on anatomic suitability, patient comorbidities and symptoms, and physician preference. Endovascular stents were placed using a brachial approach, with the choice of stent determined by physician preference. Patients who underwent endovascular stent placement (ESP) were maintained on antiplatelet therapy for 6 months postoperatively. Follow-up consisted of yearly office visits and adjunctive computerized tomography (CT) or magnetic resonance imaging (MRI) when clinically indicated. RESULTS: CT or MRI imaging identified nine patients (7 men, 2 women) with an isolated SMA dissection. One patient also had a concomitant celiac artery dissection. Median age was 70 years (range, 46-73 years). Median follow-up time was 32 months (range, 13.8-62.5 months). Presentations included an incidental radiologic finding in three patients and acute onset abdominal pain in six. Treatment included expectant management in four patients, anticoagulation in two, and ESP in three. ESP was performed primarily in two patients and in a third patient after initial management with anticoagulation failed. The reduction in the diameter of the true lumen was significantly greater in patients treated with ESP vs patients who were successfully managed expectantly or with anticoagulation (F = 15.59, P < .005). No procedural complications were associated with ESP. CONCLUSIONS: An isolated SMA dissection is a rare entity that may be managed successfully in a variety of ways based on clinical presentation. Endovascular stenting can be performed with good results and may be the preferred treatment in patients with symptomatic isolated SMA dissections.

Outcome of carotid endarterectomy for acute neurological deficit.

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.

Hemodynamic changes associated with carotid artery interventions.

Carotid artery interventions can be associated with adverse hemodynamic changes, including bradycardia and hypotension. These hemodynamic changes are believed to be caused by direct stimulation of the carotid sinus baroreceptors, mimicking normal physiological response to rises in blood pressure. During open carotid surgery, these hemodynamic changes can be controlled by direct injection of medications that block fast voltage gated sodium channels in the neuron cell membrane, thus preventing depolarization of the presynaptic neuron in the carotid sinus. This form of control is difficult or impossible during percutaneous carotid interventions because direct access to the carotid artery and carotid sinus is not available. This discussion focuses on the cause, effects, and possible treatments for the hemodynamic changes associated with carotid artery stenting procedures.

Early results for below-knee bypasses using Distaflo.

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.

Abdominal aortic aneurysm: can the arterial phase at CT evaluation after endovascular repair be eliminated to reduce radiation dose?

PURPOSE: To retrospectively determine if arterial phase computed tomographic (CT) imaging is necessary for follow-up imaging of patients who have undergone endovascular stent-graft therapy for abdominal aortic aneurysm. MATERIALS AND METHODS: This HIPAA-compliant study was exempt from institutional review board approval; informed patient consent was waived. Eighty-five patients (66 men, 19 women; mean age, 66 years; range, 45-81 years) underwent 110 multidetector CT examinations after endovascular repair of abdominal aortic aneurysms. Nonenhanced CT images were obtained. Intravenous contrast material was then injected at 4 mL/sec, and arterial and venous phase (60 seconds) CT images were obtained. The nonenhanced and venous phase images were evaluated to determine if an endoleak was present. Subsequently, arterial phase images were analyzed. The effective dose was calculated. Ninety-five percent confidence intervals as indicators of how often arterial phase imaging would contribute to the diagnosis of endoleak were determined. RESULTS: Twenty-eight type II endoleaks were detected by using combined nonenhanced and venous phase acquisitions. Twenty-five of the 28 endoleaks were also visualized during the arterial phase. Three type II endoleaks were seen only during the venous phase. The arterial phase images depicted no additional endoleaks. Seventy-eight CT examinations performed in 67 patients revealed no endoleak during the venous phase. The arterial phase images also depicted no endoleaks at these examinations. Thus, for no more than 3.1% of all examinations, there was 95% confidence that arterial phase imaging would depict an endoleak missed at venous phase imaging. Arterial phase imaging contributed to a mean of 36.5% of the effective dose delivered. CONCLUSION: Study results indicate that arterial phase imaging may not be necessary for the routine detection of endoleaks. Radiation exposure can be decreased by eliminating this phase.