Mixed convection from a discrete heater in lid-driven enclosures filled with non-Newtonian nanofluids

The transport mechanism of laminar combined convection flow of an incompressible viscous non-Newtonian nanofluid in a shear- and buoyancy-driven enclosure has been investigated in this article. The micropolar fluid model is used for the rheological behavior of the non-Newtonian fluid. A heat source with constant volumetric rate is attached in a part of the bottom wall and the remaining parts are thermally insulated. The vertical walls of the cavity are considered to be adiabatic, while the top wall is cooled and moves from left to right with uniform velocity. The thermal conductivity and the dynamic viscosity of the nanofluid are represented by different experimental correlations that are suitable to each nanoparticles. The finite volume method is applied to solve the dimensionless form of the governing equations. A discussion is provided for the effects of the governing parameters on the local Nusselt number and average Nusselt number along the heat source. It is found that an increase in the vortex-viscosity parameter causes a reduction in the local Nusselt number. As the vortex-viscosity parameter increases by 10 times from 0.5 to 5, the Nusselt number reduces by 15%. Additionally, as the nanoparticle volume fraction increases, the rate of heat transfer increases. As the volume fraction increases by 100% from 0.1 to 0.2, the Nusselt number increases by 86%.

Inflammation parallels severity of chronic venous insufficiency

Objective: This study was designed to assess the haemodynamic flow changes in patients with chronic venous insufficiency (CVI).

Methods: Duplex scanning was used to evaluate prospectively the flow characteristics in the lower limb circulation and the number of enlarged lymph nodes in the groin of normal subjects, patients with CVI classes 2, 4, 5 and 6, and patients with acute cellulitis. Phasicity and continuous flow patterns were assessed in the venous system, while the arterial system was evaluated for tri-phasic flow, absence of flow reversal and absence of flow reversal with hyperaemic flow (increased peak systolic and end diastolic velocities). Additionally, the number and size of the groin lymph nodes around the saphenofemoral junction were recorded.

Results: Patients with more severe class 4-6 CVI demonstrated an increased prevalence of abnormal flow patterns within the venous system of the leg compared to the normal phasic flow pattern seen in the absence of disease ( P < 0.001). Within the arterial system, significant changes were also observed in all three arteries studied in the legs of patients with class 4-6 CVI ( P < 0.001). For both the arterial and venous systems, no difference was noted between control limbs vs class 2 diseases or class 4-6 diseases vs cellulitis. With respect to the evaluation of inguinal lymph nodes, patients with class 2 disease were approximately four times as likely to have positive lymph nodes, and patients with more severe CVI were approximately 13 times as likely to have significant lymph nodes present.

Conclusions: This study demonstrated that patients with more advanced stages of CVI had arterial and venous flow increases similar to those seen in an acute inflammatory condition such as cellulitis. These changes were most pronounced in the perforating and subcutaneous vessels in the leg.

Enhancing needle visualization during parasagittal approach in paravertebral block for patients undergoing simple mastectomy using in-plane, multiangle ultrasound needle guidance system

Background:

Ultrasound-guided paravertebral blocks during breast surgeries with in-plane needle approaches can be challenging due to difficult needle visualization. The purpose of this study was to assess the usefulness of using a needle guide while performing in-plane parasagittal approach paravertebral block for breast surgery.

Patients and Methods:

Eighty patients, American Society of Anesthesiologists physical status I-III, aged 20-40 years with breast mass scheduled for simple mastectomy surgery, were involved in prospective, controlled, randomized study, and were randomly divided by closed envelope method into two groups: Group I (n = 40): Scheduled for ultrasound-guided paravertebral block or group II (n = 40): Scheduled for ultrasound-guided paravertebral block using the needle guide. Both techniques compared as regards: (i) Needle visibility and block performance time; (ii) number of needle passes; (iii) duration of the block; (iv) doctor and patient satisfaction; and (v) incidence of complications.

Results:

Needle visibility score was better in group II (2.92 ± 0.26 vs. 1.9 ± 0.44, P < 0.0001). Block performance time was shorter in group II (90.92 ± 15 vs. 128.25 ± 16s, P < 0.0001). A number of needle passes were less in group II (1.27 ± 0.45 vs. 2.2 ± 0.68, P < 0.0001). Doctor and patient satisfaction were better in group II (P = 0.015). No differences were found regarding the duration of the block and incidence of complications between groups.

Conclusion:

A needle guide can help reduce the time needed to perform a parasagittal in-plane thoracic paravertebral block, with a significant reduction in the block performance time, the number of needle passes, better needle visibility and better doctor and patient's satisfaction. However, there was no significant difference regarding the duration of the block or incidence of complications.

Functional and prognostic relevance of -173 G/C gene polymorphism of macrophage migration inhibitory factor in sepsis patients in Egyptian intensive care units

This study aimed to evaluate the association of plasma MIF level and -173 G/C single nucleotide polymorphism of the MIF gene with the occurrence, severity and mortality of sepsis patients. A study was conducted in adult surgical intensive care units of Zagazig University Hospitals, Egypt on 25 patients with sepsis, 27 with severe sepsis and 28 controls. Gram-negative bacilli were the most common isolates in both severe sepsis (63.0%) and sepsis (56.0%) patients. A highly statistically significant difference was found in MIF levels between sepsis cases and controls and a statistically significant difference as regards MIF level in different genotypes of the studied groups. MIF level was significantly associated with mortality in sepsis cases. High MIF levels and MIF -173G/C gene polymorphism are powerful predictors of the severity of sepsis and its outcome.

Comparison of angiotensin converting enzyme inhibitors and angiotensin II type 1 receptor blockade for the prevention of premalignant changes in the liver

AIM

We investigate and compare the possible antitumor activity of clinically used angiotensin converting enzyme (ACE) inhibitors; captopril, perindopril and angiotensin II type 1 receptor (AT1R) blocker, losartan against hepatocarcinogenesis initiated by diethylnitrosoamines (DENA) and promoted by carbon tetrachloride (CCl(4)).

MAIN METHODS

Diethylnitrosamine (DENA) (200mg/kgi.p.) initiated and carbon tetrachloride (CCl(4)) (2ml/kgi.p.) promoted hepatocarcinogenesis in male Wistar rats after 8weeks.

RESULTS

Hepatocarcinogenesis was manifested biochemically by elevation of serum hepatic tumor markers tested; α-feto protein (AFP) and carcinoembryonic antigen (CEA). In addition, hepatic carcinogenesis was further confirmed by a significant increase in hepatic tissue growth factors; vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF). Moreover a marked increase in matrix metalloproteinase-2 and hydroxyproline content were also observed. Hepatocarcinogenesis was further confirmed by a significant decrease in hepatic endostatin and metallothonein level.

KEY FINDINGS

Long-term administration of the selected drugs for 2weeks before and throughout the experimental period produced a significant protection against hepatic carcinogenesis. The present results claimed that different doses of the selected drugs succeeded in normalization of serum tumor markers. Furthermore, the drugs reduced the elevated level in the hepatic growth factors, matrix metalloproteinase-2 and hydroxyproline induced by the hepatocarcinogen. Moreover, the amelioration was also accompanied by augmentation of hepatic content of metallothionein and endostatin. Histopathological examination of liver tissues of rats treated with DENA-CCl(4) correlated with the biochemical observations.

SIGNIFICANCE

These findings suggest a similar protective effect of ACE inhibitors; captopril; perindopril and AT1R blocker, losartan against premalignant stages of liver cancer in the DENA initiated and CCl(4) promoted hepatocarcinogenesis model in rats. Therefore, RAS especially angiotensin II (Ang II) and AT1R interaction plays a pivotal role hepatocarcinogenesis development.

Controlling the sugar beet fly Pegomyia mixta Vill. with entomopathogenic nematodes

Sugar beet, Beta vulgaris L. is a strategic crop of sugar industry in Egypt. It is threatened by several insect pests among most important of them is the beet fly Pegomyia mixta. This work deals with the biological control of this insect using four entomopathogenic nematodes (EPNs). The nematodes included Steinernema carpocapsae S2, Steinernema feltiae, Heterorhabditis bacteriophora (HB1-3) and Heterorhabditis bacteriophora S1. Daily mortality of larvae and pupae of P. mixta were recorded after treatment with serial concentrations (500, 1000, 2000 and 4000 infective juveniles (IJs)/ml) of each of four studied EPNs. In the laboratory all tested nematodes killed the larvae inside their mines in the sugar beet leaves and developed in their bodies in different extends. They also killed the insect pupae in the soil and developed in their bodies. Young larvae were more susceptible than old ones. New pupae were more susceptible than old ones. In the field a single spray of S. feltiae or H. bacteriophora caused 81.3 or 75.9% reduction in the larval population of the in sugar beet leaves.

Ginger ingredients inhibit the development of diethylnitrosoamine induced premalignant phenotype in rat chemical hepatocarcinogenesis model

To investigate the possible antitumor activity of ginger extract against hepatic carcinogenesis initiated by diethylnitrosoamines (DEN) and promoted by carbon tetrachloride (CCl(4) ). A total of 60 male Wistar albino rats were divided into four groups with 15 animals in each group. Rats in group 1 (control group) received a single intraperitoneal (i.p.) injection of normal saline. Animals in group 2 were given ginger (50 mg/kg/day) in drinking water for 8 weeks. Rats in group 3 (DEN group) were injected with a single dose of DEN (200 mg/kg, i.p.), 2 weeks later received a single dose of CCl(4) (2 mL/kg i.g) by gavage as 1:1 dilution in corn oil. Animals in group 4 (DEN-ginger group) received the same carcinogenesis induction protocol as in group 3 plus ginger (50 mg/kg/day) in drinking water for 2 weeks before induction of hepatocarcinogenesis and continued throughout the experimental period. DEN-initiated and CCl(4) -promoted hepatocarcinogenesis in male Wistar rats was manifested biochemically by elevation of serum hepatic tumor markers tested; α-fetoprotein and carcinoembryonic antigen. In addition, hepatocarcinogenesis was further confirmed by a significant increase in hepatic tissue growth factors; vascular endothelial growth factor, basic fibroblast growth factor, and hydroxyproline content. A marked decrease in endostatin and metallothonein were also observed. Long-term ginger extract administration 2 weeks before induction of hepatocarcinogenesis and throughout the experimental period prevented the decrease of the hepatic content of metallothionein and endostatin and the increase in the growth factors induced by the carcinogen. Moreover, ginger extract normalize serum hepatic tumor markers. Histopathological examination of liver tissue also correlated with the biochemical observations. These findings suggest a protective effect of ginger extract against premalignant stages of liver cancer in the DEN-initiated and CCl(4) -promoted hepatocarcinogenesis model in rats.

Are Your Arteries Older Than Your Age?

PURPOSE

To determine the effect of age and atherosclerotic risk factors on the carotid intima-media layer thickness and morphology characteristics.

PATIENTS AND METHODS

Three groups of subjects were included in the study: Individuals with atherosclerotic risk factors including a family history of CHD, hypertension, hyperlipidemia, diabetes, and/or smoking (group A, n=180), age- and sex-matched healthy subjects without risk factors (group B, n=60) and a group of significantly younger volunteers (group C, n=25). The carotid artery was imaged longitudinally with B-mode ultrasound. Intima media thickness (IMT) was measured in the common (CCA) and internal carotid (ICA) arteries. Surface irregularity and continuity of the intima-media layer (IML) were assessed by high definition imaging. Echogenicity of the wall was quantified using Adobe Photoshop. The presence of calcium deposits was recorded. The double line wall pattern seen in young healthy people was used as a control to assess patterns and texture of the carotid IML. Fifteen subjects had their measurements repeated for intraobserver variability.

RESULTS

IMT measurements were reproducible in both the CCA and ICA (coefficient of variation 6% and 9%). IMT increased linearly with age (adjusted R(2)=0.72, p<0.0001), which was also an independent risk factor for increased IMT. All the risk factors had a significant association with increased IMT. In the lowest (third) decade the wall/blood interface was smooth and the double line was visualized with an echolucent center. With increased age and number of risk factors present, the wall/blood interface became more irregular (p<0.01), the double line was distorted (p<0.01) and the IML was more echogenic (p<0.01). The increase in IMT and the changes in the echogenicity of the IML were more pronounced in the ICA.

CONCLUSIONS

Age is an independent risk factor for increased IMT. Atherosclerotic risk factors are associated with the age-related changes seen in the IML. Such changes are also seen in younger asymptomatic volunteers with risk factors indicating that their arteries are older than their age.

Improved venous return by elliptical, sequential and seamless air-cell compression

AIM

The risk of deep vein thrombosis (DVT) in the peri-operative period is significant, but can be reduced with the use of mechanical intermittent pneumatic compression (IPC). These devices have reached widespread use in hospitals and have been found to be effective prophylactic measures against DVT. This study evaluates the latest design features of one particular IPC device in comparison to current models.

METHODS

Duplex ultrasound scanning was performed on 40 lower extremities of 20 healthy volunteers before and during the application of the IPC device (VenaFlow System, Aircas, NJ, USA. Two hemodynamic parameters were measured, acceleration time from spontaneous baseline venous flow and peak vein velocity. All measurements were obtained by scanning proximal to the saphenofemoral junction in the common femoral vein in both extremities for each subject. Data were obtained from 3 compression cycles and averaged for each extremity. Results were compared with a recent prospective study form our center using a slow-filling and a rapid-filling sequential IPC devices.

RESULTS

The medians for spontaneous average peak velocities at rest of the right and left lower extremities were 26 cm/s and 24.1 cm/s. The median augmented peak velocities during the compression cycle of the device in the right and left side were 79.6 cm/s and 79.0 cm/s. This represented a 306.2% increase in average peak velocity on the right side and a 327.8% increase on the left side. The median acceleration time was 305 ms +/- 40 in the left and 310 ms +/- 50 in the right limb. There was no statistically significant difference in the spontaneous and augmented velocities between the right and left lower extremities in each subject. In comparison to existing slow- and rapid-filling IPC devices the VenaFlow System had superior peak velocities and shorter acceleration times.

CONCLUSION

The use of elliptical, sequential and rapid-filling compression of the leg with overlapping air-cells produces significant hemodynamic changes in the common femoral vein, which are superior to other sequential slow- or rapid-filling IPC devices. Randomized studies should be performed to determine the efficacy of this new device in DVT prevention.

L-arginine ameliorates kidney function and urinary bladder sensitivity in experimentally-induced renal dysfunction in rats

Effects of L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) on the renal dysfunction that is induced by cisplatin (CDDP) were investigated. A single dose of CDDP (7.5 mg/kg i.p.) induced renotoxicity, which was manifested by increasing the sensitivity of isolated urinary bladder rings to acetylcholine (ACh), together with a significant elevation of serum urea and creatinine, and a severe decrease in serum albumin. Moreover, renal dysfunction was further confirmed by a significant decrease of enzyme activities, such as glutathione peroxidase, GSH-Px (E.C 1.11.1.9), catalase (E.C 1.11.1.6), as well as a significant increase in lipid peroxides that were measured as malondialdhyde (MDA) in kidney tissue homogenates. The administration of L-arginine (70 mg/kg/d p.o in drinking water 5 d before and 5 d after the CDDP injection) significantly ameliorated the renotoxic effects of CDDP, as judged by restoring the normal responses of isolated bladder rings to Ach, and also by an improvement in a range of renal function indices, which included serum urea and creatinine concentrations and kidney weight. In addition, L-arginine prevents the rise of MDA, as well as a reduction of GSH-Px and catalase activities in kidney tissues homogenates. On the other hand, the administration of L-NAME (4 mg/kg/d p.o) resulted in no protection against renal dysfunction that was induced by CDDP treatment. The findings of this study suggest that L-arginine can attenuate kidney injury that is produced by CDDP treatment. In addition, L-arginine may be a beneficial remedy for CDDP-induced renal toxicity, and could be used to improve the therapeutic index of CDDP.

Melatonin inhibits the contractile effect of vanadate in the isolated pulmonary arterial rings of rats: possible role of hydrogen peroxide

The effect and possible mechanism of action of vanadate on the isolated pulmonary arterial rings of normal rats were studied. Pulmonary arterial rings contracted in response to vanadate (0.1-1 mM) in a concentration-dependent manner. Preincubation of the pulmonary arterial rings with 1 mM melatonin significantly reduced the contractile effect of vanadate by more than 60%. Furthermore, addition of hydrogen peroxide (50 microM) or enzymatic generation of hydrogen peroxide by the addition of glucose oxidase (10 U/mL) to the medium containing glucose produced remarkable increases in the pulmonary arterial tension, 46.2 +/- 7.3 and 78.7 +/- 9.7 g tension/g tissue, respectively. Similarly, incubation of the pulmonary arterial rings with 1 mM melatonin significantly reduced the contractile responses of the arterial rings to hydrogen peroxide and glucose/glucose oxidase to 25.7 +/- 2.9 and 24.7 +/- 4.4 g tension/g tissue, respectively. Vanadate, in vitro, significantly stimulated the oxidation of NADH by xanthine oxidase, and the rate of oxidation was increased by increasing either time or vanadate concentration. Similarly, addition of melatonin to a reaction mixture containing xanthine oxidase and vanadate significantly inhibited the rate of NADH oxidation in a concentration-dependent fashion. The results of the present study indicated that vanadate induced contraction in the isolated pulmonary arterial rings, which was significantly reduced by melatonin. Furthermore, the contractile effect of vanadate on the pulmonary arterial rings may be attributed to the intracellular generation of hydrogen peroxide.

Effects of volatile oil constituents of Nigella sativa on carbon tetrachloride-induced hepatotoxicity in mice: evidence for antioxidant effects of thymoquinone

Effects of the volatile oil constituents of Nigella sativa, namely, thymoquinone (TQ), p-cymene and alpha-pinene, on carbon tetrachloride (CCl4-indued acute liver injury were investigated in mice. A single dose of CCl4 (15 microl/Kg i.p.) induced hepatotoxicity 24 h after administration manifested biochemically as significant elevation of the enzymes activities of serum alanine transaminase (ALT, EC:2.6.1.2), asparate transaminase (AST, EC:2.6.1.1) and lactate dehydrogenase (LDH, EC: 1.1.1.27). The toxicity was further evidenced by a significant decrease of non-protein sulfhydryl(-SH) concentration, and a significant increase of lipid peroxidation measued as malondialdhyde (MDA) in the liver tissues. Administration of different doses of the TQ (4, 8, 12.5, 25 and 50 mg/Kg i.p.) did not alter the chosen biochemical parameters measured, while higher doses of TQ were lethal. The LD50 was 90.3 mg/Kg (77.9-104.7, 95% CL). Pretreatment of mice with different doses of TQ 1 h before CCl4 injection showed that the only dose of TQ that ameliorated hepatotoxicity of CCl4 was 12.5 mg/Kg i.p. as evidenced by the significant reduction of the elevated levels of serum enzymes as well as hepatic MDA content and significant increase of the hepatic nonprotein sulfhydryl(-SH) concentration. Treatment of mice with the other volatile oil constituents, p-cymene or alpha-pinene did not induce any changes in the serum ALT measured. In addition, i.p. administration of these compounds 1 h before CCl4 injection, did not protect mice against CC4-induced hepatotoxicity. The results of the present study indicate that TQ (12.5 mg/Kg, i.p.) may play an important role as antioxidant and may efficiently act as a protective agent against chemically-induced hepatic damage. In contrast, higher doses of TQ were found to induce oxidative stress leading to hepatic injury.

Enhanced Generation of Leukotriene B4 From Calcium Ionophore- Stimulated Rat Peritoneal Inflammatory Cells: A Possible Clinical Relevance

Leukotrienes (LTs) producing capacity was investigated in calcium ionophore A23187-stimulated peripheral white blood cells and peritoneal inflammatory cells suspension isolated from the same rat. A reverse phase high performance liquid chromatography technique and computerized UV spectroscopy were employed to isolate and quantitate the released LTs namely, LTC(4) and LTB(4). Preincubation of rat peritoneal inflammatory cells at 37 degrees C for 5 min followed by calcium ionophore A23187 stimulation for another 5 min produced significantly elevated amounts of LTB(4) as compared to peripheral white blood cells isolated from the same rat (103+/-12.7 versus 40+/-3.6 pmol/10(7) cells, respectively; mean+/-SEM). Enhanced generation of LTB(4) was associated with production of similar amounts of LTC(4) as compared with LTC(4) produced by peripheral white blood cells (15.2+/-4.2 versus 14.6+/-2 pmol/10(7) cells, respectively). In subsequent experiments, when peritoneal inflammatory cells and white blood cells suspension isolated from the same rats were stimulated with calcium ionophore A23187 (1 micro M) after preincubation with different concentrations of exogenous arachidonic acid (1, 3 and 10 micro M), significantly higher amounts of LTB(4) were produced by the peritoneal inflamed cells while a similar amounts of LTC(4)were produced by both types of cells. Increased LTB(4) formation by rat peritoneal inflammatory cells may prove to be of pathophysiological relevance, since this compound has been described to play an important role in acute inflammatory reaction.

Alpha-lipoic acid ameliorates myocardial toxicity induced by doxorubicin

The effect of alpha-lipoic acid (LA) on the cardiotoxicity induced by doxorubicin (DOX) was investigated. A single dose of DOX (15 mg kg(-1), i.p) induced cardiotoxicity manifested biochemically by a significant elevation of serum creatine phosphokinase (CK; EC: 2.7.3.2) and lactate dehydrogenase (LDH; EC: 1.1.1.27) 48 h later. Moreover, cardiotoxicity was further confirmed by the significant increase in lipid peroxides measured as malondialdehyde (MDA), and significant decrease in protein thiols (Protein-SH) content in heart tissues. Administration of LA (100 mg kg(-1)) orally for 5 days before and 2 days after DOX injection produced a significant protection against cardiotoxicity induced by DOX. The amelioration of cardiotoxicity was evident by significant reductions in serum CK and LDH. Moreover, LA prevented the rise of MDA as well as the significant reduction of Protein-SH. These results may suggest that LA has a protective effect against cardiotoxicity induced by DOX and it may, therefore, improve the therapeutic index of DOX.

Protective effect of aminoguanidine against nephrotoxicity induced by cisplatin in normal rats

The effect of aminoguanidine (AG) on nephrotoxicity induced by cisplatin (CDDP) was investigated. A single dose of CDDP (7.5 mg/kg i.p.) induced nephrotoxicity, manifested biochemically by a significant elevation in serum urea, creatinine and a severe decrease in serum albumin. Moreover, marked increases in kidney weight, urine volume and urinary excretion of albumin were observed. Nephrotoxicity was further confirmed by a significant decrease in glutathione-S-transferase (GST, E.C. 2.5.1.18), glutathione peroxidase (GSH-Px, E.C. 1.11.1.9) and catalase (E.C. 1.11.1.6) and a significant increase in lipid peroxides measured as malondialdhyde (MDA) in kidney homogenates. Administration of AG (100 mg/kg per day p.o.) in drinking water 5 days before and 5 days after CDDP injection produced a significant protection against nephrotoxicity induced by CDDP. The amelioration of nephrotoxicity was evidenced by significant reductions in serum urea and creatinine concentrations. In addition, AG tended to normalize decreased levels of serum albumin. Urine volume, urinary excretions of albumin and GST and kidney weight were significantly decreased. Moreover, AG prevented the rise of MDA and the reduction of GST and GSH-Px activities in the kidney. These results suggest that AG has a protective effect on nephrotoxicity induced by CDDP and it may therefore improve the therapeutic index of CDDP.

Effects of thymoquinone on antioxidant enzyme activities, lipid peroxidation and DT-diaphorase in different tissues of mice: a possible mechanism of action

The present investigation focused, firstly, on the effects of oral administration of thymoquinone (TQ) on antioxidant enzyme activities, lipid peroxidation and DT-diaphorase activity in hepatic, cardiac and kidney tissues of normal mice. Superoxide dismutase (SOD; E.C:1.15.1.1), catalase (CAT; E.C:1.11.1.6), glutathione peroxidase (GSH-Px; E.C:1.11.1.9), glutathione-S-transferase (GST; E.C:2.5.1.18), and DT-diaphorase (E.C:1.6.99.2) enzyme activities in each tissue type were determined. Treatment of mice with the different doses of TQ (25, 50 and 100 mg kg(-1) day(-1) orally) for 5 successive days, produced significant reductions in hepatic SOD, CAT and GSH-Px activities. In addition cardiac SOD activity was markedly inhibited with the higher doses of TQ, (namely 50 and 100 mg kg(-1)). Moreover, TQ (100 mg kg(-1)) significantly reduced hepatic and cardiac lipid peroxidation as compared with the respective control group. Conversely, TQ (50,100 mg kg(-1)) and TQ (100 mg kg(-1)) enhanced cardiac and renal DT-diaphorase activity respectively. However, the selected doses of TQ neither produced any change in GST activity nor influenced reduced glutathione content in all tissues studied. TQ was tested, secondly, as a substrate for hepatic, cardiac and renal DT-diaphorase of normal mice in the presence of NADPH. Kinetic parameters for the reduction of TQ to dihydrothymoquinone (DHTQ) indicated that DT-diaphorase of different tissues can efficiently reduce TQ to DHTQ. K(m) and V(max) values revealed that hepatic DT-diaphorase exhibited the higher values, while the lower values were associated with renal DT-diaphorase. TQ and DHTQ were tested, thirdly, as specific scavengers for superoxide anion (generated biochemically) or as general scavengers for free radicals (generated photochemically). The results revealed that TQ and DHTQ acted not only as superoxide anion scavengers but also as general free radical scavengers. The IC(50) for TQ and DHTQ in biochemical and photochemical assays were in the nanomolar and micromolar range respectively. Our data may explain at least partly the reported beneficial in vivo protective effects of TQ through the combined antioxidant properties of TQ and its metabolite DHTQ.

Early thrombus remodelling of isolated calf deep vein thrombosis

OBJECTIVE

this prospective study was designed to evaluate the evolution of thrombus propagation and lysis in relation to patterns and distribution of isolated calf DVT.

METHODS

fifty-two limbs in 48 patients mean age 59+/-15, range 24-78 years, with isolated calf DVT that had at least one exam within 10 days of DVT detection were included in the study. Patients with a documented episode of prior DVT or evidence of post-thrombotic changes during the initial ultrasound exam were excluded. The initial thrombus length, patterns and location of the thrombi were recorded. On follow-up the propagation and lysis patterns of the clot were studied.

RESULTS

remodelling of the thrombus, excluding echotexture and vein diameter changes on ultrasound, occurred in 23 limbs, (44%). Ascending propagation only was seen in seven limbs (13%) descending propagation only in two (4%) and in both directions in five (10%). Propagation at least to popliteal vein was detected in seven limbs (13%). Thrombus developed or extended to initially uninvolved veins in six limbs (12%). Pulmonary embolism developed only in one patient (2%; 95% CI: 0-11%). The site and the size of thrombus or the number of veins involved in the baseline exam did not correlate with the remodeling of thrombus. Soleal and gastrocnemial veins were comparable with the posterior tibial and peroneal veins in terms of thrombus propagation and lysis.

CONCLUSIONS

early thrombus remodelling occurs in 44% of limbs with isolated calf DVT. This includes ascending and descending thrombus propagation and lysis. Thrombus development or propagation to initially uninvolved calf veins is found in 12%. Thrombus remodelling does not appear to be related to size, site and patterns of thrombosis.

Nonsaphenous superficial vein reflux

BACKGROUND

Information on nonsaphenous superficial venous reflux is lacking. This study was designed to determine the prevalence of reflux in nonsaphenous veins, their association and correlation with risk factors, and signs and symptoms of chronic venous disease (CVD).

METHODS

Information on 835 limbs in patients with signs and symptoms of CVD were prospectively entered into a customized database. These patients had been referred from the venous clinic to the vascular laboratory for color-flow duplex scanning evaluation of the lower-limb veins. All patients were examined for reflux in the standing and sitting positions. Nonsaphenous reflux was defined as that in superficial veins that are not part of the greater or lesser saphenous systems. Particular attention was paid to the patterns of reflux and anatomy of the nonsaphenous veins from the proximal to the distal ends, including their connections with the saphenous and deep veins.

RESULTS

Nonsaphenous venous reflux was found in 84 limbs (10%) of 72 patients, 67 of whom were women. The mean number of pregnancies in these patients was higher than that of 100 randomly selected women with saphenous reflux (3.2 vs 2.2). According to CEAP classification, 90% of the limbs were in CVD classes 1 through 3 and only 10% had skin damage (classes 4-6). Symptoms were present in 67 limbs (80%). Forty-two limbs (50%) had reflux in tributaries of lateral, posterior, and medial thigh. These veins were connected with perforators uniting with the deep femoral, femoral, and muscular veins of the thigh in 36 limbs. Reflux in these perforators was detected in 19 limbs. Reflux arising from the pelvic veins was found in 29 limbs (34%), 18 of which were from vulvar veins medial to saphenofemoral junction and 11 of which were from veins in the gluteal area. Incompetent veins from the sciatic nerve were found in nine limbs (10%). Reflux in the vein of the popliteal fossa was found in seven limbs (8%). Reflux in knee tributaries was detected in three limbs (4%), two of which were connected with posterolateral knee perforators and one with the posterior tibial nerve veins.

CONCLUSIONS

The prevalence of nonsaphenous reflux in our practice was 10%. The vast majority of these patients (93%) were women with a mean of 3.2 pregnancies. Ninety percent of these limbs have signs and symptoms assigned to CVD classes 1 to 3. These data may simply reflect the referral pattern, but also a possible association with female sex and number of pregnancies. The unusual anatomy of these veins stresses the importance of color-flow duplex scanning before surgery.

Prior treatment with captopril attenuates carbon tetrachloride-induced liver injury in mice

The present investigation focused on the possible hepatoprotective potential of captopril on carbon tetrachloride (CCl4)-induced acute liver injury in mice. Twenty-four hours after a single intraperitoneal injection of CCl4 (20 microl/Kg), hepatotoxicity was evidenced in the serum by elevated levels of aspartate transaminase (AST; EC: 2.6.1.1), alanine transaminase (ALT; EC: 2.6.1.2) and lactate dehydrogenase (LDH; EC: 1.1.1.27) and in the liver by depleted level of reduced glutathione (GSH), enhanced activity of glutathione peroxidase (GSH-Px; EC: 1I.11.1.9) and elevated level of lipid peroxides (LP). Captopril was given orally at three dose levels viz., 10, 25 and 50 mg/Kg/day for three consecutive days before subjecting the animals to the hepatotoxin. With the exception of the lowest dose namely, 10 mg/Kg/day, captopril afforded protection against CCl4-induced hepatotoxicity to different extents. Thus, the elevated activities of the enzymes AST, ALT, LDH and GSH-Px as well as the enhanced lipid peroxidation were markedly reduced below those elicited by the hepatotoxin, reaching values closer to the control, though still statistically higher. Captopril, however, did not ameliorate the depletion of GSH produced by CCl4. The data reported herein reveal a protective potential of captopril against the acute hepatotoxicity induced by CCl4 in mice. This hepatoprotection could be attributed, at least in part, to the free radical scavenging properties of the drug.

Timing of postcarotid complications: a guide to safe discharge planning

OBJECTIVES

Currently, our standard of practice is that patients undergoing carotid endarterectomy (CEA) may be safely discharged on the first postoperative day. Because many patients do not appear to require overnight observation, we wanted to determine the safety and feasibility of same-evening discharge by establishing the timing of postoperative complications, which may potentially require operative intervention.

METHODS

A total of 835 consecutive patients undergoing CEA were retrospectively reviewed. Sixty-two patients had a postoperative wound hematoma or neurologic deficit (ND) (transient ischemic attack or stroke) within 24 hours of their operation, complications potentially requiring a second operation. Excluded were 64 patients not eligible for same-day discharge because of other reasons (eg, heparinization, CEA with coronary artery bypass grafting).

RESULTS

Sixty-two patients (8.0%) had ND (26 [3.4%]) or neck hematoma (NH) (36 [4.7%]) within 24 hours of their CEA. Nineteen (73%) of the NDs were diagnosed in the operating room or recovery room, 5 (19%) within 8 hours of the operation, and 2 (7.7%) after 8 hours but in less than 24 hours. Of the NHs, 23 (66%) were diagnosed in the recovery room, 11 (31%) within 8 hours, and 1 (2.7%) after 8 hours. Of the outliers, one patient experienced a blowout of the vein graft occurring on postoperative day 1, one patient had a delayed ipsilateral stroke, and one had a vertebrobasilar stroke. Overall, only three of 773 (0.4%) patients undergoing CEA had a complication occurring more than 8 hours after operation.

CONCLUSION

NDs and NHs in post-CEA patients occurred within 8 hours of operation in 95% of those patients experiencing these complications or 99.6% of all CEA patients. These data indicate that same-evening discharge may be safely performed without increasing the adverse effects of stroke or hematoma. This plan has cautiously been initiated at this institution.

Decreased recurrent carotid stenosis by routine patching and intraoperative scanning

Our objective was to review the results of carotid endarterectomies (CEAs) with Dacron patch angioplasty and intraoperative color-flow duplex scanning (CFS). In a 3-year period, patients who underwent CEA with Dacron patch angioplasty and intraoperative CFS were studied. We excluded patients who had primary closure, vein patch, and redo endarterectomy. Serial CFS was obtained first in the early postoperative period (one day to 3 weeks), then at 6 months, and then yearly. Intraoperative CFS abnormalities were classified as major, requiring immediate revision, or minor, which were observed. The diagnosis of recurrent stenosis by US was based on the detection of an increased peak systolic frequency (>8000 MHz) or velocity (>250 cm/second) in the internal carotid artery. There were 212 CEAs performed in 200 patients (128 men and 84 women) included in this study. Three patients (1.4%) awoke with a stroke, two (0.94%) had transient ischemic attacks, and three (1.4%) developed transient hypoglossal nerve paresis. Intraoperative CFS showed a major defect that required an immediate revision in six patients (2.8%). Minor abnormalities were detected in another 41 patients (19.3%), but no revision was necessary. In follow-up three patients were identified with a severe recurrent carotid stenosis (>80%) and they underwent redo CEA. This rate of recurrence (1.4%) is significantly lower than the rate we had previously reported in a larger study (82 of 1209, 6.8%; P = 0.003). We conclude that the combined use of Dacron patch angioplasty and intraoperative CFS after CEA is associated with a low perioperative morbidity and a low incidence of recurrent stenosis in the first 2 years after operation.

Short stay carotid surgery for veterans: an emerging standard

We have taken the short stay approach to carotid artery surgery to our VA setting over the past 5 to 6 years. Retrospectively, we reviewed the efficacy and safety of that approach in 201 consecutive carotid operations over the recent 4-year period (January 1, 1996-December 31, 1999). In 1996 we had already begun the transition to an algorithm to (1) utilize carotid color flow Doppler duplex exams for diagnosis, (2) same-day admission (SDA), (3) intensive care unit (ICU) only when deemed medically necessary, and (4) next-day discharge. Results of this approach have been a decrease in the utilization of diagnostic arteriograms and utilization of the ICU from 100% previous to the onset of this approach to 17 and 22%, respectively. SDA increased from 24 to 89%. Mean LOS decreased from 5.13+/-0.9 to 1.97+/-0.4 days. The percentage of patients completing the algorithm went from 15 to 72%. Stroke and/or death varied from 0 to 3.7% each year and was only 2.4% over the 4-year period. In conclusion, this approach to short stay carotid surgery in the veteran population has proven both efficacious and safe with results similar to those in university and community practices.

A gold(I) mononuclear complex and its association into binuclear and cluster compounds by hydrogen bonding or metal ion coordination

The mononuclear Au(I) complex, Au(Spy)(PPh2py) (1), has been synthesized and characterized structurally. The complex possesses the expected linear coordination geometry with a S-Au-P bond angle of 176.03(6) degrees and no evidence of aurophilic interactions between nearest neighbor Au(I) ions in the solid state. Protonation of the pendant pyridyl groups of 1 leads to the formation of the H-bonded dimer [(Au(SpyH)(PPh2py))2](PF6)2 (2), which has also been structurally characterized. A linear coordination geometry at the Au(I) ions in 2 with a S-Au-P bond angle of 173.7(2) degrees is augmented by evidence of a strong aurophilic interaction with a Au...Au distance of 2.979(1) A. The pendant pyridyl groups of 1 have also been used to bind Cu(I) by reactions with [Cu(NCMe)4](PF6) and Cu(P(p-tolyl)3)2(NO3) leading to the formation of the heterobimetallic complexes [(AuCu(mu-Spy)(mu-PPh2py))2](PF6)2 (3) and [AuCu(P(p-tolyl)3)2(mu-Spy)(mu-PPh2py)](NO3) (4), respectively. A structure determination of 3 reveals a tetranuclear complex composed of two AuCu(mu-Spy)(mu-PPh2py)+ units held together by bridging thiolate ligands. A strong metal-metal interaction is noted between the two different d10 ions with nearest Au-Cu distances averaging 2.6395 A. The S-Au-P bond angles in 3 deviate slightly from linearity due to the Au...Cu interactions, while the coordination geometries at Cu(I) are distorted tetrahedral consisting of the two pyridyl nitrogen atoms, a bridging thiolate sulfur, and the interacting Au(I) ion. While mononuclear complex 1 is only weakly emissive in the solid state and in fluid solution, complexes 2-4 show stronger photoluminescence in the solid state and rigid media at 77 K, and in fluid solution. The emission maxima for 2-4 in ambient temperature fluid solution are 470, 635, and 510 nm, respectively. A tentative assignment of the emitting state as a S(p pi)-->Au LMCT transition is made on the basis of previous studies of Au(I) thiolate phosphine complexes. Shifts of lambda em result from the influence of H bonding or Cu(I) coordination on the filled thiolate orbital energy, or on the effect of metal-metal interaction on the Au(I) acceptor orbital energy. Crystal data for Au(Spy)(PPh2py) (1): triclinic, space group P1 (No. 2), with a = 8.3975(4) A, b = 11.0237(5) A, c = 12.4105(6) A, alpha = 98.6740(10) degrees, beta = 105.3540(10) degrees, gamma = 110.9620(10) degrees, V = 995.33(8) A3, Z = 2, R1 = 3.66% (I > 2 sigma(I)), wR2 = 9.04% (I > 2 sigma(I)) for 2617 unique reflections. Crystal data for [(Au(SpyH)(PPh2py))2](PF6)2 (2): triclinic, space group P1 (No. 2), with a = 14.0284(3) A, b = 14.1093(3) A, c = 15.7027(2) A, alpha = 97.1870(10) degrees, beta = 96.5310(10) degrees, gamma = 117.1420(10) degrees, V = 2692.21(9) A3, Z = 2, R1 = 7.72% (I > 2 sigma(I)), wR2 = 15.34% (I > 2 sigma(I)) for 5596 unique reflections. Crystal data for [(AuCu(mu-Spy)(mu-PPh2py))2](PF6)2 (3): monoclinic, space group P2(1)/c (No. 14), with a = 19.6388(6) A, b = 16.3788(4) A, c = 17.2294(5) A, beta = 91.48 degrees, V = 5540.2(3) A3, Z = 4, R1 = 3.99% (I > 2 sigma(I)), wR2 = 8.38% (I > 2 sigma(I)) for 10,597 unique reflections.

The impact of isolated lesser saphenous vein system incompetence on clinical signs and symptoms of chronic venous disease

PURPOSE

The purpose of this study was to determine the patterns of isolated lesser saphenous vein (LSV) system incompetence and correlate the distribution and extent of such reflux with symptoms and signs of chronic venous disease (CVD).

METHODS

During a 3-year period, 2254 limbs in 1682 patients with signs and symptoms of CVD were evaluated with color flow duplex scanning. Extremities with isolated reflux in the LSV system were selected for this study. Limbs with perforating venous reflux connected to this system only were also included. Limbs that had marked reflux in the greater saphenous or deep vein, that had a documented history of deep venous thrombosis, and that previously underwent surgery or sclerotherapy were excluded. The clinical severity of the limbs was graded with the CEAP classification system.

RESULTS

There were 226 limbs in 200 patients with reflux in the LSV system; 61% were female patients with a mean age of 49 years (range, 18-82 years). There were 174 patients (87%) with unilateral and 26 with bilateral disease, and 41% of the limbs belonged in CVD class 2, 26% in class 3, 12% in class 4, 3.5% in class 5, and 3% in class 6. Classes 0 and 1 were present in 14.5% of the limbs. Symptoms were present in 139 limbs (61.5%). Some degree of ache or burning sensation was the most frequent symptom (41%), followed by itching (32%), heaviness (29%), cramps (24%), and restless limbs (18%). Reflux in the main trunk of the LSV was the most prevalent (177 limbs [78%]), followed by the saphenopopliteal junction (146 limbs [64.6%]), the vein of Giacomini (39 limbs [17%]) and the gastrocnemial vein (23 limbs [10%]). Reflux involving both the saphenopopliteal junction and the LSV was seen in 50% of limbs, but almost any other combination of reflux was present, which indicated the complexity of this system. Perforator vein incompetence was detected in 56 limbs (25%). We found 83 perforator veins, resulting in a mean of 1.5 veins per limb. Both the number of incompetent perforator veins and the extent of superficial reflux correlated with clinical severity. Four main types of termination of the LSV were identified with at least nine variations. The LSV was duplicated for at least half of its length in five limbs (2.2%). Nonsaphenous reflux was detected in seven limbs (3.1%). Superficial vein thrombosis in the LSV system was found in eight limbs (3.5%), and in the gastrocnemial vein it was found in four (1.8%).

CONCLUSIONS

Isolated LSV system incompetence can cause the entire range of signs and symptoms of CVD. Clinical deterioration is associated with a longer extent of reflux and perforator incompetence. Classes 2 to 4 are the most frequent clinical presentations, whereas classes 5 and 6 are uncommon. The complex anatomy of this system and the great variation in the patterns of reflux warrant the use of color flow duplex scanning before planning treatment.

Prevalence of deep venous reflux in patients with primary superficial vein incompetence

PURPOSE

This prospective study was designed to determine the prevalence of deep reflux and the conditions under which it may occur in patients with primary superficial venous reflux and absence of deep venous thrombosis (DVT).

METHODS

We studied 152 limbs in 120 consecutive patients in the standing position who had superficial venous reflux with color flow duplex scanning. Limbs with documented evidence of DVT or post-thrombotic vein wall changes during the examination were studied but not included in the analysis. Limbs were divided into those that had at least reflux in the saphenofemoral, the saphenopopliteal, or the gastropopliteal junction and into those with nonjunctional reflux in the superficial and gastrocnemial veins. Peak velocity and duration of reflux were measured. To examine the recirculation theory, we tested the deep veins by occluding and refluxing saphenous veins 10 cm below the sampling site.

RESULTS

Thirteen limbs in 11 patients (9%) were excluded because of previous DVT. Of the remaining 139 limbs, 106 (76%) had junctional reflux. Saphenofemoral junction was involved in 89 limbs (84%), saphenopopliteal junction in 18 (17%), and gastropopliteal junction in 7 (4%). In 33 limbs (24%), reflux was detected in the main trunk or tributaries of the saphenous veins alone with no junctional incompetence. Femoral or popliteal reflux was present in 31 limbs (22%). This reflux was segmental in 27 limbs, and it was limited in the junction in 24 limbs. The mean duration of deep venous reflux was 0.9 seconds, it ranged from 0.6 to 3.7 seconds, and it was significantly shorter than that in the superficial veins (2.6 seconds; P <.0001). In the absence of junctional reflux, the prevalence of deep venous insufficiency (DVI) was significantly lower compared with that in limbs with junctional involvement (2 of 33 vs 29 of 106; P =.038). The mean duration of deep venous reflux in these groups was comparable (0.85 seconds vs 0. 91 seconds; P =.44). Occlusion of the incompetent superficial veins reduced somewhat the duration of the deep venous reflux but did not abolish it (0.88 seconds vs 0.82 seconds; P =.072). The presence of DVI was associated with junctional reflux of high peak velocity and long duration.

CONCLUSIONS

The prevalence of DVI in patients with primary superficial venous reflux and without history of DVT is 22%. However, this reflux is segmental, mainly in the common femoral vein, and is of short duration. It is associated with the presence of junctional incompetence that has a high peak velocity and long duration. These findings may explain why surgical correction of superficial reflux abolishes DVI.

Optimising the performance of intermittent pneumatic compression devices

OBJECTIVES

this study was designed to determine whether an intermittent pneumatic compression device (IPC) with an increased maximal inflation pressure, a decreased time to maximal pressure and a longer duration of compression would improve venous return compared to a standard IPC device.

METHODS

thirty limbs in 15 volunteers without evidence of venous disease were studied using duplex scanning at rest and during the application of two different IPC devices with different compression parameters. The first device IPC-1 (SCD 5325, Kendall) has a six-chambered cuff applying 45 mmHg after 12 s, sequentially from ankle to thigh followed by 60 s of non-compression. The second device IPC-2 (Vena-Assist(R), ACI Medical) has a foot, ankle and calf cuff, applies a pressure of 80 mmHg, has a pressure rise time of 0.3 s, maintains inflation for 5.5 s, and has a cycling time of 1 min. Peak venous velocity and acceleration time were measured at rest and during the IPC application. Measurements were obtained in supine position from the common femoral vein 1 cm above the saphenofemoral junction to include the entire venous outflow from the limb.

RESULTS

peak venous velocity at rest was significantly higher in the right limb than in the left limb (26+/-7.2 vs. 22+/-5.7 cm/s, p<0.01). Peak venous velocity was significantly increased by both IPC devices (p <0.0001). IPC-2 achieved significantly higher peak venous velocity than IPC-1 (55.1+/-17.8 vs. 37.4+/-6.9 cm/s, p<0.0001). Acceleration time was also found to be significantly shorter (370+/-93.4 vs. 560+/-83.5 ms, p<0.0001) in IPC-2 than in IPC-1, respectively.

CONCLUSIONS

we have demonstrated that progressive inflation at the foot, ankle and calf, increasing maximal inflation pressure and decreasing time to maximal pressure result in increased venous return. These changes may improve the efficacy of IPC devices in the prevention of deep-venous thrombosis (DVT) formation.

Protective effects of thymoquinone and desferrioxamine against hepatotoxicity of carbon tetrachloride in mice

The effects of thymoquinone (TQ) and desferrioxamine (DFO) against carbon tetrachloride (CCl4)-induced hepatotoxicity were investigated. A single dose of CCl4 (20 microl/kg, i.p.) induced hepatotoxicity, manifested biochemically by significant elevation of activities of serum enzymes, such as alanine transaminase (ALT, EC: 2.6.1.2) , aspartate transaminase (AST, EC: 2.6.1.1) and lactate dehydrogenase (LDH, EC: 1.1.1.27). Hepatotoxicity was further evidenced by significant decrease of total sulfhydryl (-SH) content, and catalase (EC: 1.11.1.6) activity in hepatic tissues and significant increase in hepatic lipid peroxidation measured as malondialdhyde (MDA). Pretreatment of mice with DFO (200 mg/kg i.p.) 1 h before CCl4 injection or administration of TQ (16 mg/kg/day, p.o.) in drinking water, starting 5 days before CCl4 injection and continuing during the experimental period, ameliorated the hepatotoxicity induced by CCl4, as evidenced by a significant reduction in the elevated levels of serum enzymes as well as a significant decrease in the hepatic MDA content and a significant increase in the total sulfhydryl content 24 h after CCl4 administration. In a separate in vitro assay, TQ and DFO inhibited the non-enzymatic lipid peroxidation of normal mice liver homogenate induced by Fe3+/ascorbate in a dose-dependent manner. These results indicate that TQ and DFO are efficient cytoprotective agents against CCl4-induced hepotoxicity, possibly through inhibition of the production of oxygen free radicals that cause lipid peroxidation.

Protective effect of thymoquinone against doxorubicin-induced cardiotoxicity in rats: a possible mechanism of protection

Administration of thymoquinone (10 mg kg(-1)day(-1), p.o.) with drinking water starting 5 days before a single injection of doxorubicin (15 mg kg(-1)i.p.) and continuing during the experimental period ameliorated the doxorubicin-induced cardiotoxicity in rats. This protection was evidenced from the significant reduction in serum enzymes: lactate dehydrogenase elevated level, 24 h and creatine phosphokinase elevated levels, 24 h and 48 h after doxorubicin administration. The cardiotoxicity of doxorubicin has been suggested to result from the generation of superoxide free-radical. The protective action of thymoquinone was examined against superoxide anion radical either generated photochemically, biochemically or derived from calcium ionophore (A23187) stimulated polymorphonuclear leukocytes. The results indicate that thymoquinone is a potent superoxide radical scavenger, scavenging power being as effective as superoxide dismutase against superoxide. In addition thymoquinone has an inhibitory effect on lipid peroxidation induced by Fe(3+)/ascorbate using rat heart homogenate. The superoxide scavenging and anti-lipid peroxidation may explain, in part, the protective effect of thymoquinone against doxorubicin-induced cardiotoxicity. 2000 Academic Press@p$hr

Expanded indications for ultrasound-guided thrombin injection of pseudoaneurysms

PURPOSE

We previously reported preliminary data on a new procedure that we developed for the treatment of femoral pseudoaneurysms after catheterization. This study presents our current results of percutaneous ultrasound-guided thrombin injection for treating pseudoaneurysms that arise from various locations and causes.

METHODS

Between February 1996 and May 1999, we performed thrombin injection of 83 pseudoaneurysms in 82 patients. There were 74 femoral pseudoaneurysms: 60 from cardiac catheterization (36 interventional), seven from peripheral arteriography (four interventional), five from intra-aortic balloon pumps, and two from dialysis catheters. There were nine other pseudoaneurysms: five brachial (two cardiac catheterization, two gunshot wounds, one after removal of an infected arteriovenous graft), one subclavian (central venous catheter insertion), one radial (arterial line), and one distal superficial femoral and one posterior tibial (both after blunt trauma). Twenty-nine pseudo-aneurysms were injected while on therapeutic anticoagulation. Patients underwent repeat ultrasound examination within 5 days and after 4 weeks.

RESULTS

Eighty-two of 83 pseudoaneurysms had initial successful treatment by this technique, including 28 of 29 in patients who were undergoing anticoagulation therapy. The only complication was thrombosis of a distal brachial artery, which resolved spontaneously. There were early recurrences in seven patients: four patients underwent successful reinjection; reinjection failed in two patients, who underwent surgical repair; and one patient had spontaneous thrombosis on follow-up. After 4 weeks, ultrasound examinations were completely normal or showed some residual hematoma, and there were no recurrent pseudoaneurysms.

CONCLUSION

Ultrasound-guided thrombin injection of pseudoaneurysms has excellent results, which support its widespread use as the primary treatment for this common problem.

Patterns and distribution of isolated calf deep vein thrombosis

PURPOSE

In the search for calf deep vein thrombosis (DVT) with color-flow duplex scanning (CFDS), most vascular laboratories investigate only the posterior tibial and peroneal veins. Few laboratories assess the soleal and gastrocnemial veins. This study was designed to determine the patterns and distribution of isolated calf DVT, including the soleal and gastrocnemial veins.

METHODS

In the last 3 years, 5250 patients (mean age, 66 +/- 15 years; range, 22 to 93 years) were referred to the vascular laboratory for clinical suspicion of DVT and underwent examination with CFDS. All superficial and deep named veins, excluding the anterior tibial from groin to ankle, were imaged. Of the deep veins in the calf, the peroneal, the posterior tibial, the gastrocnemial, and the soleal veins were examined throughout their length.

RESULTS

DVT was detected in 14% of the patients. Isolated calf DVT was detected in 282 limbs of 251 patients (4.8%). No significant difference was noted for the sex (114 men vs 137 women; P =.15) or the limb preference (145 left vs 137 right; P =.5). The peroneal veins were most frequently involved, with 115 limbs (41%) affected. The soleal veins were involved in 109 limbs (39%), followed by the posterior tibial in 105 limbs (37%) and the gastrocnemial in 79 limbs (29%). Thrombus in the soleal vein alone was found in 57 limbs (20%), in the gastrocnemial in 48 limbs (17%), in the peroneal in 41 limbs (15%), and in the posterior tibial vein in 35 limbs (12%). Thrombus confined to a single or paired vein was found in 181 limbs (64%). Thrombus involving two different veins (27%) was the second most frequent pattern, and thrombus in three (7%) or four (1.4%) different veins was less prevalent. Isolated thrombosis in veins not routinely investigated was found in 113 limbs (40%; soleal, n = 57; gastrocnemial, n = 48; soleal + gastrocnemial, n = 8). Multifocal origin of thrombosis, defined as thrombi in two different veins that do not anatomically communicate, was identified in 63 limbs (22%).

CONCLUSION

Forty percent of the patients with acute isolated calf DVT would be judged to have normal CFDS examination results if the muscular veins in the calf were not imaged. Multifocal origin of thrombosis was found in 22% of the involved limbs. The prevalence of thrombosis in any calf vein either alone or in combination is comparable. Accordingly, the soleal and gastrocnemial veins should be examined routinely.

Higher prevalence of abdominal aortic aneurysms in patients with carotid stenosis but without diabetes

BACKGROUND

We compared abdominal aortic aneurysm (AAA) prevalence in 3 groups of patients at the Hines Veterans Affairs Medical Center: (1) patients with 50% or more carotid stenosis, (2) patients with less than 50% stenosis, and (3) patients screened for the Aneurysm Detection and Management (ADAM) study.

METHODS

Of all the patients referred to the vascular laboratory for carotid duplex examination during a 12-month period, patients with 50% or more carotid stenosis underwent ultrasonography of the abdominal aorta unless they had a previous scan or previous aortic surgery (group 1, n = 374). Patients with less than 50% carotid stenosis who had been screened for ADAM comprised group 2 (n = 139). They were compared with all patients screened for ADAM at our center during the same time period (group 3, n = 2477).

RESULTS

AAA of 3.0 cm or more were present in 18.2%, 12.2%, and 7.2% of groups 1, 2, and 3, respectively; AAA of 4.0 cm or more were present in 8.3%, 5.8%, and 2.1% of groups 1, 2, and 3, respectively. Among patients with carotid stenosis, those patients without diabetes accounted for the observed increase in prevalence (21.9 % > or = 3.0 cm and 10.2% > or = 4.0 cm vs 9.2% and 2.8% in patients with diabetes).

CONCLUSIONS

The relative risk of AAA is 2 to 3 times greater in patients with carotid stenosis compared with patients undergoing routine screening. However, only patients without diabetes account for the increased prevalence. Selective AAA screening of patients who are not diabetic with carotid stenosis is recommended.

Primary superficial vein reflux with competent saphenous trunk

OBJECTIVES

because reflux in superficial vein tributaries is most often collectively reported with the main saphenous veins, its importance remains largely unrecognised. This study was designed to identify the distribution and extent of non-truncal superficial venous reflux and its association with the signs and symptoms of chronic venous disease (CVD).

PATIENTS AND METHODS

eighty-four limbs in 62 patients with signs and symptoms of CVD and evidence of reflux on continuous-wave Doppler were subsequently examined with colour-flow duplex imaging. Incompetent superficial vein tributaries were imaged throughout their extent and both ends were identified. Limbs with reflux in the main trunk of the saphenous veins or the deep, perforator or muscular veins, superficial or deep vein thrombosis, injection sclerotherapy, varicose-vein surgery, arterial disease and inflammation of non-venous origin were excluded from the study. The CEAP classification system was used for staging clinical severity of CVD.

RESULTS

the prevalence of tributary reflux alone was 9.7% (84/860). Reflux was detected in 171 tributaries. The number of incompetent tributaries ranged from 1 to 5 per limb. Most prevalent were the tributaries to the greater saphenous (111, 65%<0. 0001), followed by those of lesser saphenous (33, 19%) or a combination of both (12, 7%). Incompetent non-saphenous tributaries were uncommon (15, 9%). Among the named tributaries in the lower limb the posterior arch vein was most often incompetent (46, 27%) followed by the anterolateral vein of the thigh (30, 18%), the medial accessory vein (16, 9%) and the anterior arch vein (14, 8%). Reflux in above-the-knee tributaries alone was found in 18 limbs (21%), in below the knee in 23 (28%) and in both sites in 43 (51%). The vast majority of the limbs (71%,p <0.0001) belonged to CVD class 2, 14% in class 3, 9% in class 1 and only 6% in class 4. Class 3 and 4 patients tended to have a longer duration of signs and symptoms, higher number of incompetent tributaries per limb and also a higher prevalence of combined above- and below-knee reflux.

CONCLUSIONS

these data indicate that reflux confined to superficial tributaries is found throughout the lower limb. Because this reflux is present without greater and lesser saphenous trunk, perforator and deep-vein incompetence or proximal obstruction, it shows that reflux can develop in any vein without an apparent feeding source. Greater saphenous tributaries are affected significantly more often than those of lesser saphenous, while non-saphenous reflux is uncommon. Most limbs have signs and symptoms of CVD class 2 and 15% belong in classes 3 and 4.

New insights into perforator vein incompetence

BACKGROUND

there has been much controversy on the role of perforator veins in the development of chronic venous disease (CVD). This study was designed to determine the duration and direction of flow of lower limb perforator veins (PVs) in relation to their location, diameter and competency status of superficial and deep veins, in healthy volunteers and patients with different grades of CVD.

PATIENTS AND METHODS

thirty limbs in 15 symptom-free volunteers and 103 limbs in 75 patients with signs and symptoms of CVD were examined with colour-flow duplex scanning. Superficial, perforator and deep veins were studied in the standing and sitting positions. Flow-velocity characteristics, the number and maximum PV diameter at the deep fascia and subfascially were determined. A PV was considered incompetent when the outward flow lasted >0.5 s.

RESULTS

581 PVs were found in the patients and 106 in the volunteers. 163 PVs (28%) were incompetent in the first group and none in the latter. The total number of PVs and the number of incompetent PVs per limb increased significantly with the severity of CVD. The mid-calf area had more competent and incompetent PVs in patients (p <0.01). Mean diameter of incompetent PVs in all the CVD classes was significantly larger than that of competent PVs. Competent PVs tended to be larger with increasing severity of CVD and they were significantly larger in the CVD classes 4 to 6 compared to controls (p <0.01). Subfascial PV diameter was markedly larger than that at the fascial level (p <0.001) regardless of the CVD class. A subfascial PV diameter of >3.9 mm (95% CI 3.4 to 4.4 mm) indicated incompetence. However, the reverse was not true, because about a third of incompetent PVs had a subfascial diameter of <3.9 mm. Both competent and incompetent PVs were smaller when located at the lower thigh, knee, ankle and anterior aspect of the calf than those found in the rest of the calf and mid-thigh (p =0. 03). Both inward and outward flow was found more often in patients than in controls (70/418 vs. 9/106, p =0.048). Most incompetent PVs had outward flow alone (126, 77%). PV incompetence was most frequently associated with reflux in superficial veins (120, 74% (p <0.0001), followed by reflux in both the superficial and deep veins (34, 21%) and reflux in the deep veins alone (9, 5%). The mean duration of outward flow was markedly longer in the presence of both superficial and deep vein reflux compared to superficial (p <0.001) or deep vein reflux alone (p <0.0001).

CONCLUSIONS

the number of incompetent PVs and the diameter of both competent and incompetent PV increases with the severity of CVD. Bidirectional PV flow is more common in patients than in normal volunteers, while 77% of the incompetent PVs have outward flow alone. PV incompetence is most often associated with reflux in the superficial veins, indicating that deep venous reflux is rarely the primary cause of PV insufficiency.

The new operating room environment

As endovascular procedures become more complex, the need for a suitably equipped endovascular suite is recognized. This specialized theater combines the features of the traditional operating room and the interventional radiology suite. The availability of high-resolution digital fluoroscopy facilitates the precise deployment of endovascular grafts and stents. In addition, combined open and endovascular procedures can be performed simultaneously. In this new environment, vascular surgeons are able to select the most appropriate operation without hindrance.

Timing and frequency of perioperative carotid color-flow duplex scanning: A preliminary report

PURPOSE

The results of intraoperative and early postoperative carotid color-flow duplex scanning (CFS) after endarterectomy were reviewed to determine whether any perioperative studies could be eliminated.

METHODS

Patients undergoing carotid endarterectomy with intraoperative CFS between 1986 and 1997 were identified. Early postoperative CFS was performed between 1 day and 3 weeks postoperatively, then it was performed again at 6 months postoperatively.

RESULTS

During the study period, 560 patients, 325 men and 235 women, underwent 621 carotid endarterectomies. A satisfactory intraoperative carotid CFS was completed in 611 (98.4%) patients. There were 20 (3.2%) vessels with a major defect that required revision for fronds or flaps (n = 11), retained atheroma (n = 5), low flow (n = 2), high velocity or turbulence (n = 1), or dissection (n = 1). Another 146 vessels (23.5%) had minor defects, such as retained proximal atheromas or small (less than 3 mm) fronds, but were not revised. The remaining 445 vessels were normal. The first postoperative CFS was normal in all the revised carotids and in 138 (94.5%) vessels with minor intraoperative defects. At 6 months, recurrent stenosis (more than 75% area reduction) was identified in 1 of 18 revised carotids (5.5%), 4 of 138 vessels (2. 9%) with minor defects, and 17 of 406 vessels (4.2%) that were normal intraoperatively. The incidence of recurrent stenosis was not significantly different in the three groups (P =.7).

CONCLUSION

Intraoperative CFS is useful because major unsuspected defects can be corrected immediately, thus avoiding potential neurologic morbidity. However, the postoperative day 1 CFS can be eliminated in most cases, because it does not provide any relevant clinical information.

Effect of captopril on doxorubicin-induced nephrotoxicity in normal rats

Biochemical evaluations of the effects of the sulfhydryl-containing angiotensin-converting enzyme inhibitor (captopril) on the nephrotoxicity induced by doxorubicin in normal rats were carried out. A single dose of doxorubicin (15 mg kg-1) which caused nephrotoxicity was manifested biochemically by the elevation of serum urea after 24 and 48 h of administration. Also a severe decrease in total proteins and albumin after 4, 24 and 48 h was observed. Moreover, a decrease of non-protein sulfhydryl (-SH) concentrations in the kidney tissues after 24 h and an increase in the lipid peroxidation was observed after 4 h administration of doxorubicin. Captopril (60 mg kg-1 i.p.) injection did not induce any change in the biochemical parameters measured, however, captopril administered 1 h before doxorubicin ameliorated the biochemical toxicity induced by doxorubicin. This was evidenced by a significant reduction in serum urea and the lipid peroxidation after 4 and 24 h and a significant reduction in creatinine after 48 h. Also, the captopril amelioration was evidenced by an increase in total proteins and albumin after 4 and 24 h of doxorubicin administration. Captopril did not change non-protein sulfhydryl (-SH) concentrations or protein content in the kidney tissues. These results suggest that captopril may be beneficial as a protective agent against nephrotoxicity induced by doxorubicin.

Management of acute mesenteric ischemia

Acute mesenteric ischemia is a serious illness requiring prompt surgical attention. The clinical presentation, diagnostic strategy, and management of this disease are reviewed. Options for revascularization are briefly outlined.

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE

The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning.

METHODS

During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes.

RESULTS

New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease.

CONCLUSION

Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.

Enhanced generation of leukotriene B4 and superoxide radical from calcium ionophore (A23187) stimulated human neutrophils after priming with interferon-alpha

The present study was designed to investigate the effect of interferon-alpha ( INF-alpha) on the production of leukotrienes (LTs) and superoxide radicals when intact human neutrophils were stimulated with calcium ionophore (A23187). A reverse phase high performance liquid chromatography and UV spectroscopy were employed to detect and quantitate the released LTs; namely LTC4, LTB4 and its trans isomers, 6-trans LTB4 and 12-epi-6-trans LTB4. Preincubation of intact human neutrophils at 37 degrees C for 30 min with INF-alpha and stimulation with calcium ionophore A23187 for 1 min enhanced significantly the formation of LTB4. Preincubation of intact human neutrophils with INF-alpha and subsequent stimulation with calcium ionophore A23187 also enhanced significantly superoxide radical generation that reduced nitroblue tetrazolium into blue formazan. The in vivo effect of INF-alpha in rats demonstrated that the higher dose of INF-alpha that induced superoxide radical and LTB4 by A23187 stimulated intact human neutrophil in vitro, also induced a significant decrease in white blood cells and RBCs started at 4 h after i.p administration. The differential white blood cell count revealed that, the prime target for INF-alpha is the white blood cells of myeloid origin. These results might demonstrate the modulatory effects of INF-alpha on granulocyte functions.

Acute effects of intermittent pneumatic compression on popliteal artery blood flow

OBJECTIVES

To investigate the immediate effects of intermittent pneumatic foot and calf compression (IPFCC) on popliteal artery blood flow in symptom-free volunteers and to determine the reproducibility of color flow duplex imaging in the popliteal artery.

DESIGN

Cohort study.

SETTING

A university associated tertiary care hospital.

PATIENTS

Forty lower limbs of 30 volunteers without symptoms or noteworthy risk factors of peripheral vascular disease.

INTERVENTIONS

Popliteal artery blood flow was measured in the sitting position before, during, and after the application of IPFCC using color flow duplex imaging. The interobserver, intraobserver, and between occasion within-subject variability of the popliteal artery blood flow were evaluated in 5 symptom-free volunteers who had at least 5 color flow duplex imaging measurements taken at each of the above time points on 3 different days.

MAIN OUTCOME MEASURES

The arterial diameter, peak systolic, end diastolic, and reverse-flow velocities were measured, as well as the duration of forward flow during diastole before, during, and after IPFCC. The same variables were measured in 5 separate volunteers by 3 different observers, on 3 separate days, at 3 separate times to determine reproducibility.

RESULTS

Including all types of variability, the popliteal artery blood flow varied from 8% to 39% with a mean value of 19%. Since the diameter of the artery was obtained with less than 5% variability, the time average mean velocity was responsible for the high variation in flow. During application of the IPFCC, the popliteal artery blood flow increased significantly in all subjects (P<.001). The mean increase in the flow was 2.4 times the baseline values. The diameter of the arteries remained unchanged while the time average velocity increased significantly (P<.001). This velocity increase was due to marked elevation in the peak systolic and end diastolic velocities and diminution of the reverse-flow component, as well as a prolongation of the forward flow during diastole. After cessation of the pump, flow returned to baseline levels (P=.41)

CONCLUSIONS

Ultrasound-derived popliteal artery blood flow measurements show moderate variability. The application of IPFCC greatly enhances popliteal artery blood flow. The flow increase is due to a dramatic drop in the peripheral vascular resistance as the peak systolic and end diastolic flow velocities increase and the reverse-flow component diminishes. Its role in the treatment of lower extremity occlusive arterial disease needs to be determined.

Compensatory arterial enlargement is a common pathobiologic response in early atherosclerosis

BACKGROUND

Human arteries are dynamic conduits that respond to different stimuli by remodeling their structure and size. Arterial dilatation has been shown to occur in moderate and advanced atherosclerosis in studies that evaluated only one artery, either coronary, carotid, or superficial femoral artery (SFA). The purpose of this study was to quantify and compare compensatory arterial enlargement throughout the peripheral vascular system in early atherosclerosis.

METHODS

Seventy-two patients (40 male, 32 female, mean age 67 +/- 12 years) underwent transcutaneous B-mode ultrasound imaging during routine examinations. Thirty-nine carotid, 19 aorta, 19 iliac, 23 common femoral (CFA), 21 SFA, and 23 popliteal arteries were longitudinally imaged. Eight healthy volunteers (6 male, 2 female, mean age 27 +/- 2.2 years) had the same arteries evaluated (n = 48). Internal diameter (ID) and external diameter (ED) were measured in disease-free areas and in paired adjacent areas exhibiting increased intima-media thickening (IMT) and small atherosclerotic plaques. The percent change in ID, ED, IMT, and plaque thickness were calculated.

RESULTS

There was no observed change in ID or ED in all arteries of the healthy volunteers. When compared with normal vessel segments, all arteries demonstrated a marked decrease in ID and increase in ED in areas of small, hemodynamically insignificant plaque. The aorta had a 6.00% +/- 1.92% increase in ED, which was significantly less than the percent increase in ED observed in carotid (8.14 +/- 4.5%. P = 0.05), CFA (9.73 +/- 3.54%, P = 0.0001), SFA (9.15 +/- 4.25%, P = 0.005), and popliteal arteries (9.67 +/- 4.34, P = 0.002). In all arteries there was a strong correlation between plaque thickness and percent change in ED with the best correlation observed in the popliteal artery (R2 = 0.823, P < 0.0001). IMT was significantly increased in all normal vessel segments of the patients when compared with the healthy volunteers (P < 0.001).

CONCLUSION

All peripheral arteries dilate in response to intima-media thickening and early atherosclerotic plaque formation. This adaptive response occurs at the site of the lesion to preserve luminal area. The percent change in ED is strongly related to plaque thickness and is greatest in the more distal arteries.

Intra-aortic balloon counterpulsation in patients with severe cardiac dysfunction undergoing abdominal operations

OBJECTIVE

To assess the effectiveness of intra-aortic balloon counterpulsation (IABC) as adjunctive treatment in patients undergoing abdominal operations.

DESIGN

Retrospective review of patient medical records to determine the incidence of mortality following abdominal surgery and the incidence of complications from IABC.

SETTING

University-based, tertiary care hospital.

PATIENTS

Sixty-eight patients who underwent an abdominal operation and IABC during the same hospitalization were divided into the following groups: Group 1, IABC initiated prior to operation to enhance perioperative cardiac function; group 2, IABC used to treat cardiogenic shock in a patient who subsequently required an operation while undergoing IABC; and group 3, IABC device inserted and removed for treatment of cardiogenic shock in a patient who subsequently required an operation within 30 days of removal of the device.

MAIN OUTCOME MEASURES

The incidence of mortality in IABC-supported patients and IABC-related complications.

RESULTS

In group 1, excluding 3 patients who died following emergency operation, 26 patients underwent nonemergency procedures and had a 12% mortality rate. In group 2, 5 of 6 patients who underwent emergency operations died, whereas 3 of 4 patients who required only urgent operations survived. In group 3, 18 (62%) of 29 patients who underwent urgent or emergent operations died postoperatively. Thirteen patients experienced complications related to IABC; there were no deaths and no limbs were lost to ischemia.

CONCLUSIONS

This is the largest reported series looking at the utility of IABC as adjunctive treatment for patients undergoing abdominal operations. The outcome for those patients requiring emergency operations remains poor, but it is likely that more liberal use of IABC in patients with severe cardiac dysfunction who require nonemergency operations may improve patient outcome.

Percutaneous ultrasound guided thrombin injection: a new method for treating postcatheterization femoral pseudoaneurysms

PURPOSE

Since its introduction in 1991, ultrasound guided compression repair of postcatheterization femoral artery pseudoaneurysms has been shown to be effective. Disadvantages of ultrasound guided compression repair include patient discomfort during compression, inability to treat noncompressible pseudoaneurysms, prolonged use of ultrasound equipment and personnel, limited success with patients being treated with anticoagulants, and some early recurrences. We conducted a prospective study to evaluate a new method of treating femoral pseudoaneurysms, percutaneous ultrasound guided thrombin injection.

METHODS

Under duplex ultrasound guidance, a 22- or 25-gauge needle was percutaneously positioned within the pseudoaneurysm. Without compressing the pseudoaneurysm, 0.5 to 1 ml thrombin solution (1000 U/ml) was injected to induce thrombosis. Early in the study, the procedure was modified to allow more than one injection. After successful thrombosis, the patients were kept at rest in bed for at least 1 hour. Duplex ultrasound examination was repeated in 1 to 4 days. Distal pulses and ankle-brachial indexes were measured before and after the procedure.

RESULTS

Twenty of 21 consecutive pseudoaneurysms were successfully treated with thrombin injection. Fifteen pseudoaneurysms thrombosed immediately (<20 seconds) after one injection. The other five had partial thrombosis after one injection and complete thrombosis immediately after a second injection. The one failure occurred in a patient who had only one injection and then underwent subsequent ultrasound guided compression repair, which failed. No patient required sedation or analgesia during thrombin injection. There were no procedure-related complications and no recurrences.

CONCLUSIONS

Percutaneous ultrasound guided thrombin injection appears to be a safe and expeditious method for treating postcatheterization femoral pseudoaneurysms. It has significant advantages with respect to ultrasound guided compression repair or surgical repair.

Recurrent carotid stenosis: prevention, surveillance, and management

Carotid endarterectomy has come under closer scrutiny, perhaps more than any other surgical procedure. Many studies have shown excellent early results; however, recurrent carotid stenosis is a recognized complication arising in the postoperative follow-up period. The local and systemic factors that may contribute to recurrent stenosis are reviewed. The results of noninvasive postoperative surveillance are examined, and a rational schedule is proposed. Finally, the diagnosis of recurrent stenosis and its surgical management with redo endarterectomy are discussed.