Outcomes of Preferential Early Carotid Endarterectomy following Recent Stroke.

BACKGROUND: With the risk of recurrent ischemic stroke being highest in the first week following transient ischemic attack or stroke, the current guidelines of "early" endarterectomy within 2 weeks still leave potential vulnerability for patients with a significant bifurcation lesion and a new stroke. The intent of this analysis is to determine the safety of carotid endarterectomy even earlier than the current guidelines, based on a single surgeon experience of more than 12 years. SUMMARY BACKGROUND DATA: Although there has been a progressive movement toward earlier intervention following acute ischemic stroke in the presence of a culprit bifurcation lesion, most of the recommendations still are for performance of endarterectomy within two weeks following the event. This compression is welcome but given that the risk of recurrent stroke is highest within the first week following stroke, there is a reason to evaluate an earlier time frame for carotid endarterectomy (CEA). METHODS: A retrospective review of all CEA performed by a single surgeon over a 12-year period was performed. Patient demographics, Modified Rankin score (mRS) whenever documented, degree of internal carotid artery (ICA) stenosis, and preoperative neurologic symptoms were recorded. The 30-day outcomes including stroke, transient ischemic attack, death, and other major complications were tabulated. RESULTS: A total of 444 patients (mean age 74 ± 10.1) underwent a total of 465 CEAs. Two hundred and twenty-eight (49%) CEAs were for a symptomatic disease: of these, 194 had a documented stroke. One hundred and eighty-one stroke patients (93%) underwent CEA within 72 hr and the remaining 13 patients within 5 days. Of the stroke cohort, for whom the mRS was available, the mean preCEA mRS was 3.4. One patient in the stroke cohort had a postoperative stroke (0.5%, 1/194). In the total CEA cohort, there were 3 total postoperative strokes (0.6%, 3/465). There was one death in the total cohort (0.2%). The mean operative time was 45 min ± 4 min. CONCLUSIONS: Early CEA for recurrent stroke prevention can be performed safely, at an earlier time frame than current recommendations. Given the safety of early CEA and the risk of recurrent stroke, CEA for stroke is best done early with no additional increase in morbidity or mortality.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms (PAAs) leverage the work of a panel of experts chosen by the Society for Vascular Surgery to review the current world literature as it applies to PAAs to extract the most salient, evidence-based recommendations for the treatment of these patients. These guidelines focus on PAA screening, indications for intervention, choice of repair strategy, management of asymptomatic and symptomatic PAAs (including those presenting with acute limb ischemia), and follow-up of both untreated and treated PAAs. They offer long-awaited evidence-based recommendations for physicians taking care of these patients.

Direct imaging and quantification of carotid plaque calcification.

Carotid plaque calcification normally appears as a signal void with clinical MR sequences. Here, we describe the use of an adiabatic inversion recovery prepared two-dimensional ultrashort echo time sequence to image and characterize carotid plaque calcification using a clinical 3-T scanner. T(1), T 2*, and free water content were measured for seven carotid samples, and the results were compared with micro-CT imaging. Conventional gradient echo and fast spin echo images were also acquired for comparison. Correlations between T(1), T 2*, free water concentration, and mineral density were performed. There was a close correspondence between inversion recovery prepared two-dimensional ultrashort echo time morphologic and micro-CT appearances. Carotid plaque calcification varied significantly from sample to sample, with T(1) s ranging from 94 ± 19 to 328 ± 21 msec, T 2*s ranging from 0.31 ± 0.12 to 2.15 ± 0.25 msec, and free water concentration ranging from 5.7 ± 2.3% to 16.8 ± 3.4%. There was a significant positive correlation between T(1)(R = 0.709; P < 0.074), T 2* (R = 0.816; P < 0.025), and free water concentration, a negative correlation between T(1) (R = 0.773; P < 0.042), T 2* (R = 0.948; P < 0.001) and CT measured mineral density, and a negative correlation between free water concentration (R = 0.936; P < 0.002) and mineral density.

Bilateral upper extremity vascular injury as a result of a high-voltage electrical burn.

High-voltage electrical burns are rare but cause devastating injuries, resulting in potential limb loss and major morbidity and mortality. These injuries are more insidious than flame burns in that the extent of the injury is not obvious at first glance. Damage to underlying muscle, nerve, and vessels may occur, resulting in limb-threatening ischemia and delayed hemorrhage. The management of such injuries remains controversial and can be challenging for the vascular and reconstructive surgeon. We present a case of high-voltage electrical injury to bilateral upper extremities resulting in limb-threatening ischemia, review the literature on the management of such injuries, and propose an algorithm to guide the management of these devastating injuries.

Lessons learned from the institution of the Surgical Care Improvement Project at a teaching medical center.

BACKGROUND: The Surgical Care Improvement Project (SCIP) was designed to reduce perioperative complications. We describe our institutional experience in 6 major areas: surgical site infection, venous thromboembolism prevention, use of perioperative beta-blockade, serum glucose level greater than 200 mg/dL, normothermia, and the use of electric razors for hair removal. METHODS: This was a retrospective review of surgical cases. Evidence-based training and standardization of system and process were undertaken. Compliance with SCIP guidelines was determined. RESULTS: Overall SCIP compliance improved from 80% to 94% over a 2-year period. Standardized antibiotic dosing times improved compliance to more than 90%. Appropriate preoperative antibiotic choice improved to 100%. Cessation of antibiotics postoperatively within 24 hours remains a difficult task. Venous thromboembolism prophylaxis has been difficult to achieve because of postoperative bleeding concerns. Administration of beta-blockers has remained one of the most difficult problems to correct because of the multiplicity of avenues by which a patient may arrive to the operating suite. CONCLUSIONS: Achievement of the SCIP goals is a formidable, but achievable, process requiring individual, cultural, systems, and institutional changes to achieve success.

Complete femoral artery and vein avulsion from a hyperextension injury: a case report and literature review.

Blunt peripheral extremity vascular injuries are much less frequent than those of penetrating injuries, especially in the absence of significant musculoskeletal trauma. We present an unusual case of complete femoral artery and vein avulsion that resulted from a forced hip hyperextension and thigh abduction after slipping when a patient's foot became entrapped in a ladder. The patient presented with an acutely ischemic right lower extremity 8 hr postinjury, which necessitated immediate surgical exploration, temporary intravascular shunting, interposition grafting, and prophylactic fasciotomy. To our knowledge, this is the first such mechanism to be reported resulting in complete transection of both femoral artery and vein. We review the mechanism of injury and management.

A role for VEGF as a negative regulator of pericyte function and vessel maturation.

Angiogenesis does not only depend on endothelial cell invasion and proliferation: it also requires pericyte coverage of vascular sprouts for vessel stabilization. These processes are coordinated by vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) through their cognate receptors on endothelial cells and vascular smooth muscle cells (VSMCs), respectively. PDGF induces neovascularization by priming VSMCs/pericytes to release pro-angiogenic mediators. Although VEGF directly stimulates endothelial cell proliferation and migration, its role in pericyte biology is less clear. Here we define a role for VEGF as an inhibitor of neovascularization on the basis of its capacity to disrupt VSMC function. Specifically, under conditions of PDGF-mediated angiogenesis, VEGF ablates pericyte coverage of nascent vascular sprouts, leading to vessel destabilization. At the molecular level, VEGF-mediated activation of VEGF-R2 suppresses PDGF-Rbeta signalling in VSMCs through the assembly of a previously undescribed receptor complex consisting of PDGF-Rbeta and VEGF-R2. Inhibition of VEGF-R2 not only prevents assembly of this receptor complex but also restores angiogenesis in tissues exposed to both VEGF and PDGF. Finally, genetic deletion of tumour cell VEGF disrupts PDGF-Rbeta/VEGF-R2 complex formation and increases tumour vessel maturation. These findings underscore the importance of VSMCs/pericytes in neovascularization and reveal a dichotomous role for VEGF and VEGF-R2 signalling as both a promoter of endothelial cell function and a negative regulator of VSMCs and vessel maturation.

Chapter 7. Mouse models of ischemic angiogenesis and ischemia-reperfusion injury.

Ischemia and ischemia-reperfusion (I/R) events are distinct but interrelated processes etiologic to the most prevalent human diseases. A delicate balance exists whereby ischemic injury can result in beneficial angiogenesis or in detrimental reperfusion injury overwhelming the organism. Here, we describe in vivo models of ischemia and ischemia-reperfusion injury with emphasis on murine hindlimb ischemia models. We also provide a brief introduction to murine myocardial ischemia experiments. Each model is described in the context of human disease. Emphasis is made on the strengths and weaknesses of the available techniques, particularly as it relates to data analysis, interpretation, and translational relevance.

The brachial artery-brachial vein fistula: expanding the possibilities for autogenous fistulae.

OBJECTIVE: The National Kidney Foundation Dialysis Outcomes and Quality Initiative recommends autogenous access for new dialysis procedures. The patient requiring hemodialysis with inadequate superficial arm veins represents a formidable challenge to the surgeon. Our objective is to describe results with an alternative access procedure, the autogenous brachial-brachial artery (ABBA) access in patients with inadequate superficial arm veins. METHODS: One surgeon created 163 new dialysis accesses in 122 patients during 40 consecutive months at a university hospital. There was 97% patient follow-up. All patent but diminutive superficial arm veins as judged by preoperative ultrasound were explored. Arms with inadequate veins at exploration or arms with thrombosed veins on ultrasound received either prosthetic or ABBA procedures. Upper-arm access was often staged, involving a second "superficialization" procedure. This is a retrospective case series based on a comprehensive medical record review. Cox proportional hazards models were used to compare access patency for individual as well as multiple factors suspected or known to influence dialysis access outcomes. Society for Vascular Surgery reporting guidelines were used except where specifically noted and justified otherwise. RESULTS: One hundred thirty-five autogenous and 28 prosthetic dialysis operations were performed. Primary patency for all access procedures at 12, 24, and 36 months was 58%, 50%, and 38%, respectively. Primary assisted patency for all access procedures at 12, 24, and 36 months was 97%, 91%, and 85%, respectively. Secondary patency at 12, 24, and 36 months was 99%, 97%, and 97%, respectively. Finally, functional patency at 12, 24, and 36 months was 71%, 67%, and 44.0%, respectively. Of the 122 patients, 70 patients received either ABBA or prosthetic access. ABBA out-performed prosthetic access in terms of primary patency (hazard ratio for prosthetic vs ABBA: 4.21 (95% confidence interval [CI]: 1.49, 11.91) and functional patency (hazard ratio for prosthetic vs ABBA: 6.27 95% CI: 1.24-31.72) in patients referred early. Functional patency was more likely to be compromised in elderly patients and in patients with hypercoagulable diagnoses. CONCLUSIONS: Autogenous brachial-brachial access for dialysis out-performed prosthetic access with respect to primary and functional patency in patients referred early without differences in overall complications.

Allogeneic endometrial regenerative cells: an "Off the shelf solution" for critical limb ischemia?

Critical limb ischemia (CLI) is an advanced form of peripheral artery disease which is responsible for approximately 100,000 amputations per year in the US. Trials to date have reported clinical improvement and reduced need for amputation in CLI patients receiving autologous bone marrow or mobilized peripheral blood stem cells for stimulation of angiogenesis. While such treatments are currently entering Phase III trials, practical and scientific pitfalls will limit widespread implementation if efficacy is proven. Hurdles to be overcome include: a) reduced angiogenic potential of autologous cells in aged patients with cardiovascular risk factors; b) invasiveness/adverse effects of bone marrow extraction and G-CSF mobilization, respectively; and c) need for on-site cellular manipulation. The Endometrial Regenerative Cell (ERC) is a mesenchymal-like stem cell derived from the menstrual blood that is believed to be associated with endometrial angiogenesis. We discuss the possibility of using allogeneic ERCs as an "off the shelf" treatment for CLI based on the following properties: a) High levels of growth factors and matrix metalloprotease production; b) Ability to inhibits inflammatory responses and lack of immunogenicity; and c) Expandability to great quantities without loss of differentiation ability or karyotypic abnormalities.

Carotid endarterectomy as the criterion standard in high-risk elderly patients.

BACKGROUND: Carotid angioplasty and stenting (CAS) is now a viable alternative to carotid endarterectomy (CEA) in patients considered to be high-risk candidates for surgery, despite recent reports of increased adverse periprocedural outcomes in elderly patients. We sought to evaluate our single-institution experience and the 30-day perioperative outcomes of CEA in patients 75 years or older, who are traditionally considered high-risk surgical candidates and are recommended for CAS. DESIGN: Retrospective medical record review. SETTING: Academic tertiary care center. PATIENTS: All patients 75 years or older undergoing CEA during a 16-year period. MAIN OUTCOME MEASURES: Primary outcome of 30-day perioperative stroke, death, or myocardial infarction (MI) and a composite outcome of stroke, death, or MI. Secondary outcomes of all perioperative complications were exclusive of primary outcomes. RESULTS: One hundred seventeen CEAs were performed in 110 patients 75 years or older. Significant medical comorbidities were well represented among the group. Among the patients, 50.4% were symptomatic, 60.7% had greater than 90% carotid stenosis, and 44.4% had contralateral disease. Primary outcome for any stroke, death, or MI was 1.7%, 0.9%, or 3.4%, respectively, with a composite event rate of any stroke or death of 2.6%. One or more secondary outcomes were experienced by 26.5% of patients. CONCLUSIONS: Carotid endarterectomy in elderly patients with significant comorbidities, traditionally thought to be a high-risk undertaking, is a safe procedure with periprocedural risks of stroke, death, and MI equivalent to those of younger patients. In light of the increased stroke risk in elderly patients with CAS, CEA remains the criterion standard for prevention of stroke in this patient population.

Percutaneous intervention for infrainguinal occlusive disease in women: equivalent outcomes despite increased severity of disease compared with men.

OBJECTIVES: Experience with open surgical bypass suggests similar overall outcomes in women compared with men, but significantly increased risk of wound complications. Percutaneous treatment of lower extremity occlusive disease is therefore an attractive alternative in women, although it is not clear whether there is a difference in outcomes between women and men treated with this technique. We sought to determine the results and predictors of failure in women treated by percutaneous intervention. METHODS: Percutaneous infrainguinal revascularization was performed on 309 women between 2001 and 2006. Procedures, complications, demographics, comorbidities, and follow-up data were entered into a prospective database for review. Patency was assessed primarily by duplex ultrasonography. Outcomes were expressed by Kaplan-Meier curves and compared by log-rank analysis. RESULTS: A total of 447 percutaneous interventions performed in 309 women were analyzed and compared with 553 interventions in men. Mean age in women was 73.2 years; comorbidities included hypertension (HTN) (86%), diabetes melitus (DM) (58%), chronic renal insufficiency (CRI) (15%), hemodialysis (7%), hypercholesterolemia (52%), coronary artery disease (CAD) (42%), and tobacco use (47%). Indications in women included claudication (38.0%), rest pain (18.8%), and tissue loss (43.2%). Overall primary & secondary patency and limb-salvage rates for women were 38% +/- 4%, 66% +/- 3%, and 80% +/- 4% at 24 months. In this patient sample, women were significantly more likely than men to present with limb-threatening ischemia (61.6% vs 47.3%, P < 0.001) and have lesions of TASC C and D severity (71.4% vs 61.7%, P < .005). However, there were no significant differences in primary and secondary patency rates or limb-salvage rates between genders. Furthermore, while women with limb-threat, diabetes, and advanced TASC severity lesions were at increased risk of failure overall, there were no differences between women and men with these characteristics. CONCLUSIONS: Percutaneous infrainguinal revascularization is a very effective modality in women with lower extremity occlusive disease. Although women in this sample were more likely to present with limb-threat than men, patency and limb-salvage rates were equivalent between genders, even in high-risk subsets such as diabetics or those with lesions of increased TASC severity.

Endovascular dialysis interventions in the era of DOQI.

The National Kidney Foundation Dialysis Outcomes and Quality Initiative (DOQI) recommends autogenous fistulae as the preferred access for new dialysis procedures. Unfortunately, despite superior patency rates compared to prosthetic grafts, even autogenous access durability is often undermined by venous stenosis due to intimal hyperplasia at the outflow vein or by central venous stenosis due to long-standing central venous catheters. Salvage interventions, in the form of endovascular treatments such as percutaneous transluminal angioplasty (PTA) and/or stenting, are increasingly utilized for access salvage and maintenance. The objective of this study was to evaluate the efficacy of endovascular dialysis interventions in the era of DOQI. A retrospective review of a database of endovascular interventions for dialysis access during 36 months at an academic medical center was performed. Both central venous and access outflow lesions were included in the analysis. Kaplan-Meier curves and log-rank analysis were used to assess and compare time-dependent variables. Forty-five patients with dialysis access underwent 72 endovascular interventions for access maintenance. There were 27 central venous and 32 outflow endovascular interventions with 98% follow-up. Primary and assisted primary patency rates for outflow balloon PTA were 50% and 72% at 12 months, respectively. There were 1.1 reinterventions required per index outflow PTA procedure. Postintervention primary patency rates for central venous PTA were 30% and 9% at 6 and 12 months, respectively. Postintervention assisted patency for central venous PTA was 100% at 12 months, requiring 1.8 reinterventions per index PTA. Central venous and venous outflow interventions extended overall access patency by 38.5 and 33 months, respectively (p < 0.0001). Endovascular interventions are the mainstay of treatment for the malfunctioning dialysis access. Despite the need for multiple reinterventions and close surveillance, catheter-based interventions positively contribute to dialysis access durability in accordance with DOQI guidelines.

Renal stenting for incidentally discovered renal artery stenosis: is there any outcome benefit?

We evaluated whether there was a clinical outcome benefit in patients incidentally discovered to have high-grade renal artery stenosis (RAS) and treated with percutaneous transluminal renal angioplasty and stenting (PTRAS) at the time of angiogram for another indicated procedure. A retrospective chart review was performed on all patients undergoing renal arteriography over 4 years at our academic tertiary-care referral center. Review of catheterization reports was used to identify patients diagnosed with high-grade RAS (reduction of > or =70% luminal diameter by arteriogram). Patients treated with PTRAS were identified. Baseline and postprocedure blood pressure (BP, an average of at least three independent measurements), glomerular filtration rate, serum creatinine, and antihypertensive medication regimen were compared for 12 months of follow-up. Over 4 years, 124 patients underwent renal arteriography and 78 (63%) were diagnosed with high-grade RAS. Fifty-eight patients (74% of those with high-grade RAS) received PTRAS. Patients treated with PTRAS had similar baseline characteristics to those with high-grade RAS with no intervention, with the exception of lower diastolic BP (DBP; 74 +/- 11.2 vs. 80 +/- 14.2 mm Hg, p = 0.04) and a higher proportion of hyperlipidemia (78 vs. 55%, p = 0.05). Thirty-eight out of 58 PTRAS patients (66%) received sufficient follow-up to assess outcomes. When baseline and postprocedure variables were compared in PTRAS patients with 12-month follow-up, there was a reduction in systolic BP (SBP, 153 +/- 20.8 vs. 136 +/- 27.2 mm Hg, p = 0.01) and mean arterial pressure (MAP, 103 +/- 11.2 vs. 95 +/- 14 mm Hg, p = 0.04). When these patients were stratified by those with an increase, decrease, or no change in postprocedure antihypertensive medications, significant reductions in SBP, MAP, and DBP were noted only in the patient population that also had an increase in the number of antihypertensive medications. No differences in renal insufficiency were detected. Patients with high-grade RAS incidentally discovered during arteriography performed for extrarenal disease and treated with PTRAS have a modest reduction in BP, which is significant only in those patients with an increased number of antihypertensive medications postprocedure. Caution must be taken in stenting patients with incidental RAS as outcome benefit may be minimal when compared to medical management only.

Surgical bypass of symptomatic central venous obstruction for arteriovenous fistula salvage in hemodialysis patients.

Venous hypertension due to proximal central venous outflow obstruction coexisting with a functioning arteriovenous fistula in the ipsilateral arm presents with a complex management problem in hemodialysis patients. Ligation of the arteriovenous communication is the simplest procedure to relieve symptoms; however, this sacrifices the patient's hemodialysis access, which may be the only available access in that patient. Surgical bypass of the occlusion is a potential option as it obviates the symptoms of venous hypertension while preserving dialysis access. Our objective was to evaluate our experience and outcome with dialysis patients undergoing surgical bypass for symptomatic central venous obstruction and dialysis access salvage. There were three hemodialysis patients with severe venous hypertension secondary to subclavian vein obstruction who had functioning ipsilateral arteriovenous fistulae. All underwent cephalic vein (n = 2) or axillary vein (n = 1) to internal jugular vein bypass of the obstructed subclavian segment via an 8-mm polytetrafluoroethylene bridge graft. All patients had unsuccessful percutaneous transluminal angioplasty (PTA) attempts prior to surgical bypass. In two patients, a wire could not be passed through the occlusion; in the third, PTA was only transiently successful despite four repeated procedures. All patients had complete resolution of symptoms without operative mortality. The bypass grafts remained patent, allowing the arteriovenous fistulae to provide functional access for the entire duration of follow-up after surgery (3-8 months). Surgical bypass of a central vein obstruction relieves the symptoms of venous hypertension and prolongs the use of the existing hemodialysis access. This surgical option should be well recognized within the dialysis community.

Inelastic compression legging produces gradient compression and significantly higher skin surface pressures compared with an elastic compression stocking.

The purposes of this study were to (1) investigate compression levels beneath an inelastic legging equipped with a new pressure-adjustment system, (2) compare the inelastic compression levels with those provided by a well-known elastic stocking, and (3) evaluate each support's gradient compression production. Eighteen subjects without venous reflux and 12 patients with previously documented venous reflux received elastic and inelastic compression supports sized for the individual. Skin surface pressures under the elastic (Sigvaris 500, 30-40 mm Hg range, Sigvaris, Inc., Peachtree City, GA) and inelastic (CircAid C3 with Built-in-Pressure System [BPS], CircAid Medical Products, San Diego, CA) supports were measured using a calibrated Tekscan I-Scan device (Tekscan, Inc., Boston, MA). The elastic stocking produced significantly lower skin surface pressures than the inelastic legging. Mean pressures (+/- standard error) beneath the elastic stocking were 26 +/- 2 and 23 +/- 1 mm Hg at the ankle and below-knee regions, respectively. Mean pressures (+/- standard error) beneath the inelastic legging with the BPS were 50 +/- 3 and 38 +/- 2 mm Hg at the ankle and below-knee regions, respectively. Importantly, our study indicates that only the inelastic legging with the BPS produces significant ankle to knee gradient compression (p = .001).

Prophylactic balloon occlusion of the internal iliac arteries to treat abnormal placentation: a cautionary case.

Massive hemorrhage from abnormal placentation is a leading cause of postpartum maternal death and hysterectomy after cesarean section. The endovascular surgeon and radiologist are increasingly asked to assist in the management of these complex patients with the placement of bilateral internal iliac artery balloon catheters. We report the case of a 27-year-old woman with placenta percreta with preemptive bilateral internal iliac artery balloons who had iliac artery thrombosis and acute limb ischemia develop 7 hours after cesarean hysterectomy. This is the first report of iliac artery thrombosis in this setting. A review of the vascular and obstetrical literature reveals divergent recommendations for the use of this technique in patients with abnormal placentation. No guidance from rigorous prospective evidence is available and thus we offer recommendations for the cautious use of this modality.

Spontaneous dissection of the carotid and vertebral arteries: the 10-year UCSD experience.

The etiology of spontaneous dissection of the carotid and vertebral arteries without antecedent trauma remains unclear. The goal of this 10-year review was to examine factors regarding presentation, diagnosis, treatment, and outcome for all patients at our institution who were diagnosed with spontaneous carotid dissections (SCD) or spontaneous vertebral dissections (SVD) with no prior trauma history. A retrospective chart analysis was performed involving all discharges from UCSD Medical Center from 1995 to 2005. Patients were selected for inclusion based on the diagnosis of carotid or vertebral dissection with no associated traumatic or iatrogenic cause for their presentation. Characteristics of these patients' medical risk factors, presenting symptoms, diagnostic method and time, treatment, and outcomes were analyzed. A total of 20 patients (10 male, age 44.8 +/- 12.9 yrs; 10 female, age 39.6 +/- 14.9 yrs) were included for study. These patients represented 12 cases of SCD and nine SVD. On presentation, a majority of patients with both SVD and SCD reported headache as their primary complaint while a significantly higher rate of nausea (25% vs. 67%, p < 0.01) was reported in SVD. SVD was associated with a significantly longer diagnostic time (11 hr vs. 16 hr, p < 0.01). The most commonly performed diagnostic exam in both SCD and SVD was magnetic resonance angiography (MRA). Anticoagulation was the primary treatment in 11 of 12 SCD and all nine SVD. One patient with persistent, symptomatic bilateral carotid dissection after anticoagulation was treated with stent placement resulting in unilateral intracranial hemorrhage (ICH). Length of stay was significantly longer in SVD (5 d vs. 7 d, p < 0.02). A significantly higher incidence of persistent neurologic deficits on discharge was seen in SCD (71% vs. 33%, p < 0.02). Radiographic evidence of cerebral infarction on discharge had a stronger correlation with clinical deficits in SCD. Although there were only two cases, those treated with endovascular therapy in the setting of SCD suffered complications related to the intervention. On discharge, there did not seem to be a correlation between persistent neurologic deficits and radiographic evidence of infarction in SVD reflecting that recovery after these episodes may not be predictable based on the appearance of the infarction.

A novel fluorescence-based cellular permeability assay.

Vascular permeability is a pathologic process in many disease states ranging from metastatic progression of malignancies to ischemia-reperfusion injury. In order to more precisely study tissue, and more specifically cell layer permeability, our goal was to create a fluorescence-based assay which could quantify permeability without radioactivity or electrical impedance measurements. Human aortic endothelial cells were grown in monolayer culture on Costar-Transwell clear polyester membrane 6-well cell culture inserts. After monolayer integrity was confirmed, vascular endothelial growth factor (VEGF(165)) at varying concentrations with a fixed concentration of yellow-green fluorescent 0.04 microm carboxylate-modified FluoSpheres microspheres were placed in the luminal chamber and incubated for 24 h. When stimulated with VEGF(165) at 20, 40, 80, and 100 ng/ml, this assay system was able to detect increases in trans-layer flux of 8.2+/-2.4%, 16.0+/-3.7%, 41.5+/-4.9%, and 58.6+/-10.1% for each concentration, respectively. This represents the first fluorescence-based permeability assay with the sensitivity to detect changes in the permeability of a cell layer to fluid flux independent of protein flux; as well as being simpler and safer than previous radioactive-and impedance-based permeability assays. With the application of this in vitro assay to a variety of pathologic conditions, both the dynamics and physiology relating to cellular permeability can be more fully investigated.