Julianne Stoughton

Management of venous leg ulcers: clinical practice guidelines of the Society for Vascular Surgery ® and the American Venous Forum.

Thomas F. O’Donnell Jr, MD, Marc A. Passman, MD, William A. Marston, MD, William J. Ennis, DO, Michael Dalsing, MD, Robert L. Kistner, MD, Fedor Lurie, MD, PhD, Peter K. Henke, MD, Monika L. Gloviczki, MD, PhD, Bo G. Eklof, MD, PhD, Julianne Stoughton, MD, Sesadri Raju, MD, Cynthia K. Shortell, MD, Joseph D. Raffetto, MD, Hugo Partsch, MD, Lori C. Pounds, MD, Mary E. Cummings, MD, David L. Gillespie, MD, Robert B. McLafferty, MD, Mohammad Hassan Murad, MD, Thomas W. Wakefield, MD, and Peter Gloviczki, MD

Comparison of simultaneous electroencephalographic and mental status monitoring during carotid endarterectomy with regional anesthesia

PURPOSE This study examines the accuracy of intraoperative electroencephalographic (EEG) monitoring for the detection of cerebral ischemia by comparing EEG with simultaneous mental status evaluation (MSE) during carotid endarterectomy in awake patients. METHODS Between 1994 and 1997, 208 consecutive carotid endarterectomies were prospectively evaluated for cerebral function during surgery with simultaneous MSE and EEG monitoring. Regional anesthesia (RA), which consisted of superficial cervical block, was chosen preferentially in 75% of the cases, with general anesthesia (GA) reserved for the patients who did not fulfill the criteria for RA. When available, 8-channel EEG monitoring was performed (59% with RA and 55% with GA). RESULTS The EEG was a reliable predictor in comparison with MSE in most but not all cases of cerebral ischemia. Significant neurologic changes were noted using MSE in 4 of 89 patients (4.5%) that were not detected using EEG (false negative results). Conversely, 6 of 89 cases (6.7%) showed unilateral slowing without associated changes in MSE (false positive results). For the awake patients, 21 of 150 cases (14%) showed MSE changes that required a shunt. By contrast, 9 of 32 GA cases (28%) showed EEG changes that would have led to shunting (P = NS). In the RA group, there were no strokes versus 3 of 58 cases (5.2%) with strokes in the GA group. Two of 150 cases (0.1%) had transient ischemic attacks in the RA group. There was 1 myocardial infarction in the GA group; no deaths occurred in this series. CONCLUSION EEG monitoring yielded a significant number of false positive (6.7%) and false negative (4.5%) results in the detection of neurologic deficits when compared with MSE in the awake patients. In this series, the preferential use of RA resulted in less shunt use and was possibly associated with a lower stroke rate.

Factors Influencing the Incidence of Endovenous Heat-Induced Thrombosis (EHIT)

Introduction: Extension of thrombus from the great saphenous vein into the common femoral vein can be an early postprocedural complication of endothermal ablation (ETA). Methods: A retrospective review was performed over a 3-year period. Intraprocedural ultrasound images demonstrating the distance of the catheter tip to the saphenofemoral junction (SFJ) were available for 519 procedures, and this distance was measured. Results: Twenty-one (4.0%) cases of endovenous heat-induced thrombus (EHIT) were diagnosed. In all, 15 (6.4%) EHITs occurred following endovenous laser ablation and 6 (2.1%) after radiofrequency (P = .02). Distance from catheter tip to SFJ, vein diameter, concomitant treatments, and perioperative anticoagulation were not significant risk factors for EHIT. Of the clinical factors assessed, gender (P = .002), Clinical, Etiologic, Anatomic and Pathophysiologic classification 3 to 6 (P = .003), history of prior thrombosis (P = .04), and Caprini thrombosis risk factor assessment score (P = .004) were significant. On multivariate analysis, Caprini score (P = .0002) and male gender (P = .0003) remained significant. Conclusions: Male gender and increased Caprini score are predictive factors for EHIT following ETA.

Pathogenesis of Varicose Veins

Despite the high prevalence of varicose veins and the recent surge in research on the condition, the precise mechanisms underlying their development remain uncertain. In the past decade, there has been a shift from initial theories based on purely mechanical factors to hypotheses pointing to complex molecular changes causing histologic alterations in the vessel wall and extracellular matrix. Despite progress in understanding the molecular aspects of venous insufficiency, therapies for symptomatic varicose veins are directed toward anatomic and physical interventions. The present report reviews current evidence identifying the underlying biochemical alterations in the pathogenesis of varicose veins.

Plasminogen acceleration of urokinase thrombolysis

PURPOSE A relative deficiency of plasminogen within the thrombus may be the rate limiting factor in clot lysis. METHODS To investigate this hypothesis, we used an in vitro perfusion system and expanded polytetrafluoroethylene graft segments filled with radiolabeled human thrombus. Three groups of five perfusions were compared: (1) urokinase infusion (333 IU/min) into clots laced with buffer, (2) urokinase infusion (333 IU/min) into clots laced with plasminogen (44 CU), and (3) control, D5W infusion into clots laced with buffer. Two end points were measured over time: the amount of lysed thrombus and the flow through the graft. RESULTS Urokinase infusion resulted in augmented flow through the graft when compared with control (p < 0.05). Lacing with plasminogen resulted in more rapid restoration of flow when compared with urokinase infusion alone (p < 0.05). Similarly, the rate of clot dissolution was significantly greater in plasminogen-laced thrombi (p < 0.05) when compared with the control and urokinase groups. Embolization of particles of thrombus was uniformly observed in the urokinase group, resulting in a temporary decrease in flow through the thrombosed graft. This event characteristically occurred after 60 minutes of infusion but was never seen in the urokinase/plasminogen treatment group. CONCLUSIONS These results suggest that plasminogen supplementation of urokinase thrombolysis may result in significant clinical benefits with respect to the rate of clot lysis and the uniformity of clot dissolution with a lower likelihood of secondary embolization.

Thrombus formation on polytetrafluoroethylene surfaces: the importance of von Willebrand factor

The importance of von Willebrand factor (vWf) in the formation of platelet-fibrin thrombi on expanded polytetrafluoroethylene (ePTFE) surfaces was studied in an in vitro system, perfusing non-anticoagulated human blood over ePTFE grafts for 3 min at varying shear rates (100, 500 and 1500/s shear). Platelet (111In) and fibrin (125I) deposition was assessed on ePTFE surfaces in the presence and relative absence of vWf, achieved by use of polyclonal anti-vWf antibody (anti-vWf Ab). A total of 29 perfusions were performed. Increasing shear rate was associated with greater platelet deposition in the presence of vWf (p < 0.001). This shear-dependent rise in platelet deposition was not observed when vWf was blocked by anti-vWf Ab (P < 0.1), confirming the role of vWf in platelet deposition at high shear rates. Fibrin deposition increased with increasing shear rate in the presence of vWf (P < 0.01). Inhibiting vWf abolished the shear-dependent increase in fibrin deposition. These data suggest that vWf plays a critical role in platelet and fibrin thrombus formation on ePTFE surfaces. These effects are particularly important under conditions of high shear rate. These mechanisms may lead to the observed pathologic thrombus formation and platelet-dependent neointimal processes occurring at areas of high shear rate within the anastomotic regions of ePTFE grafts.

Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veins

Aims Extracellular matrix remodelling has been implicated in a number of vascular conditions, including venous hypertension and varicose veins. However, to date, no systematic analysis of matrix remodelling in human veins has been performed. Methods and results To understand the consequences of venous hypertension, normal and varicose veins were evaluated using proteomics approaches targeting the extracellular matrix. Varicose saphenous veins removed during phlebectomy and normal saphenous veins obtained during coronary artery bypass surgery were collected for proteomics analysis. Extracellular matrix proteins were enriched from venous tissues. The proteomics analysis revealed the presence of >150 extracellular matrix proteins, of which 48 had not been previously detected in venous tissue. Extracellular matrix remodelling in varicose veins was characterized by a loss of aggrecan and several small leucine-rich proteoglycans and a compensatory increase in collagen I and laminins. Gene expression analysis of the same tissues suggested that the remodelling process associated with venous hypertension predominantly occurs at the protein rather than the transcript level. The loss of aggrecan in varicose veins was paralleled by a reduced expression of aggrecanases. Chymase and tryptase β1 were among the up-regulated proteases. The effect of these serine proteases on the venous extracellular matrix was further explored by incubating normal saphenous veins with recombinant enzymes. Proteomics analysis revealed extensive extracellular matrix degradation after digestion with tryptase β1. In comparison, chymase was less potent and degraded predominantly basement membrane-associated proteins. Conclusion The present proteomics study provides unprecedented insights into the expression and degradation of structural and regulatory components of the vascular extracellular matrix in varicosis.

Streptococcal toxic shock syndrome from a puncture wound to the foot

Puncture wounds to the foot are a common occurrence. If treated properly, the majority will be resolved without major complications. Toxic shock syndrome and streptococcal toxic shock-like syndrome are devastating complications of some staphylococcal and streptococcal infections. This paper discusses the similarities and differences between the two toxic states, reviews the pathophysiology, and presents a case report of near-fatal streptococcal toxic shock-like syndrome secondary to a puncture wound of the foot.

Venous ablation therapy: indications and outcomes.

Venous disease has long been recognized as a progressive, debilitating, and recurrent problem. Until recently, venous insufficiency was often undertreated due to a lack of therapeutic modalities. During the past decade, an explosion in the treatment options has occurred. Endovenous ablation therapy has nearly replaced the conventional surgical treatments for patients with superficial venous insufficiency. Dramatic changes in therapy are also available for deep venous thrombosis but are not the subject of this review. These newer techniques are much less invasive and consequently have reduced risks of wound complications or bleeding. In addition, they can be performed easily in the office setting with local anesthesia. Higher-risk patients can now be considered for these less invasive treatments to reduce their ambulatory venous hypertension. With the lower procedural risks and the dramatically shortened recovery times, earlier intervention can be entertained. This helps prevent the development of venous stasis ulceration and other sequelae of progressive venous insufficiency.

Thrombolysis with prourokinase versus urokinase: An in vitro comparison

PURPOSE Despite advantages demonstrated in vitro, no single thrombolytic agent has been clearly shown to be superior to another in the clinical setting. Prourokinase has recently received attention as a new thrombolytic agent with higher fibrin specificity. The thrombolytic activity of prourokinase, however, remains ill defined. The purpose of this study was to evaluate thrombolysis with prourokinase in comparison to urokinase in vitro. METHODS We used an in vitro parallel channel perfusion model that simulates catheter-directed thrombolysis in the peripheral arterial system. Radiolabeled thrombi were subjected to 90 minutes of endhole catheter-directed infusion with either prourokinase 5000 IU/ml, urokinase 5000 IU/ml; or 5% dextrose in water at 4 ml/hr. RESULTS Prourokinase and urokinase were found to be equivalent with respect to thrombolytic effect. Percent lysis was maximal at 90 minutes in both the urokinase and prourokinase groups. Prourokinase and urokinase were found to be equally effective in restoring flow through thrombosed graft segments. CONCLUSION Prourokinase appears to offer little benefit over urokinase with respect to thrombolytic activity in an in vitro model that closely resembles the clinical setting. If prourokinase is to be accepted as an alternative to urokinase, advantages must relate to differences in fibrin specificity.