Outcome of carotid artery stenting in the hands of vascular surgeons.

OBJECTIVES: To analyze the procedural and clinical outcomes of carotid artery stenting (CAS) in the hands of endovascular trained vascular surgeons. METHODS: Between April 2008 to May 2013, 1197 patients were treated for extracranial internal carotid artery (ICA) stenosis. The proportion of endovascular treated patients was 5.0% (CAS n = 60 vs. carotid endarterectomy (CEA) n = 1137). All patients in the CAS group (44 males, median age 70 years) were treated by two senior vascular surgeons experienced in endovascular methods. Restenosis was the indication for CAS in 32 out of 60 patients (53.3%). Further indications were contralateral ICA occlusion (n = 14, 23.3%), radiogenic ICA stenosis (n = 5, 8.3%), high-risk candidates for CEA (n = 4, 6.6%), and the presence of contralateral recurrent paresis (n = 2, 3.3%). High-risk patients for CEA were defined as patients with history of severe cardiac disease and patients with impaired general condition. 84.4% (n = 27) of the restenosis were asymptomatic with a mean degree of stenosis of 83.7%, and 12.9% (n = 4) were symptomatic (degree of stenosis of 90%). Mean procedural and fluoroscopy time were 61 and 14 min. Study endpoints were periprocedural stroke-related mortality and morbidity, restenosis rate, and overall survival. Follow-up was performed by duplex ultrasound with a median follow-up period of 12 months (range 1-55). RESULTS: The periprocedural stroke rate of CAS within 30 days was 3.3% (one ischemic stroke, one intracranial hemorrhage); two additional patients suffered TIA (3.3%). None of the patients had a myocardial infarction perioperatively. The mortality rate was 0. CAS procedures were completed in 90.0% (n = 54) of cases. Dropout rate was 8.3% (n = 5) for morphological reasons (e.g., carotid kinking). Intraoperative complication rate was 1.7% (n = 1) including one patient who suffered intraoperative rupture of access vessels. The conversion rate with subsequent CEA procedure was 6.6% (n = 4 of 5). The restenosis rate during follow-up was 3.3% after CAS. The reintervention rate during the median follow-up period of 12 months (1-55 months) was 5.5% (n = 3/54). Two patients received a reintervention with successful balloon angioplasty; in one case, a diagnostic angiography was performed excluding the presence of a relevant restenosis. No additional stent was implanted. The survival rate was 100% at 1 year, 90.4% at 2 years, and 77.7% at 3 years. CONCLUSION: CAS, in the hands of vascular surgeons, is feasible with a moderate perioperative risk in a highly selected patient cohort. A procedure termination rate of approximately 10% shows that the complementary therapy using CAS procedure is not overused by surgeons.

Comparison of morphological and rheological conditions between conventional and eversion carotid endarterectomy using computational fluid dynamics--a pilot study.

PURPOSE: To compare postoperative morphological and rheological conditions after eversion carotid endarterectomy versus conventional carotid endarterectomy using computational fluid dynamics. BASIC METHODS: Hemodynamic metrics (velocity, wall shear stress, time-averaged wall shear stress and temporal gradient wall shear stress) in the carotid arteries were simulated in one patient after conventional carotid endarterectomy and one patient after eversion carotid endarterectomy by computational fluid dynamics analysis based on patient specific data. PRINCIPAL FINDINGS: Systolic peak of the eversion carotid endarterectomy model showed a gradually decreased pressure along the stream path, the conventional carotid endarterectomy model revealed high pressure (about 180 Pa) at the carotid bulb. Regions of low wall shear stress in the conventional carotid endarterectomy model were much larger than that in the eversion carotid endarterectomy model and with lower time-averaged wall shear stress values (conventional carotid endarterectomy: 0.03-5.46 Pa vs. eversion carotid endarterectomy: 0.12-5.22 Pa). CONCLUSIONS: Computational fluid dynamics after conventional carotid endarterectomy and eversion carotid endarterectomy disclosed differences in hemodynamic patterns. Larger studies are necessary to assess whether these differences are consistent and might explain different rates of restenosis in both techniques.

Comparison of gadofosveset (Vasovist(®)) with gadobenate dimeglumine (Multihance(®))-enhanced MR angiography for high-grade carotid artery stenosis.

OBJECTIVE: To prove superiority of blood pool contrast agent gadofosveset over conventional contrast agent gadobenate dimeglumine for assessment of stenotic internal carotid artery (ICA). METHODS: Eleven patients with high-grade ICA stenosis (≥75%), confirmed by duplex sonography, underwent MR angiography (MRA) with gadofosveset and gadobenate dimeglumine. RESULTS: Agreement in stenosis grade was reached in 7 of 10 stenotic ICAs. In two ICAs, gadobenate dimeglumine led to underestimation of stenosis grade. There was a significant difference in signal intensity (pre-/post-stenotic segments), showing higher values for gadofosveset (P<0.01; P<0.05). Impression of contrast intensity with gadofosveset was better in 8 ICAs and only in 1 ICA with gadobenate dimeglumine (P<0.05). CONCLUSION: Gadofosveset-enhanced MR angiography may be superior for assessment of high-grade ICA stenosis compared with gadobenate dimeglumine MR angiography.

Eversion carotid endarterectomy is associated with decreased baroreceptor sensitivity compared to the conventional technique.

OBJECTIVE: Impairment of baroreceptor sensitivity (BRS) has been shown to be associated with blood pressure instability after carotid endarterectomy (CEA). The aim of this study was to determine whether there is a difference in postoperative BRS changes following eversion CEA (E-CEA) and conventional CEA (C-CEA). METHODS: Sixty-four patients undergoing E-CEA (n = 37) and C-CEA (n = 27) were prospectively studied. Non-invasive measurements of mean arterial pressure (MAP), cardiac output (CO) and total peripheral resistance (TPR) were perioperatively obtained over three 10-min periods. Baroreflex gain was calculated as the sequential cross-correlation between heart rate and beat-to-beat systolic blood pressure. RESULTS: Compared with changes observed after C-CEA, E-CEA was associated with an increase in systolic pressure (SP) (P = 0.01), diastolic pressure (DP) (P = 0.008), MAP (P = 0.002) and heart rate (HR) (P = 0.03) on postoperative day 1 (POD-1). BRS decreased after E-CEA from 6.33 to 4.71 ms mmHg(-1) on POD-1 (P = 0.001) and to 5.26 ms mmHg(-1) on POD-3 (P = 0.0004). By contrast, BRS increased after C-CEA from 4.59 to 6.13 ms mmHg(-1) on POD-1 (P = 0.002) and to 6.27 ms mmHg(-1) on POD-3 (P < 0.0001). CONCLUSION: E-CEA and C-CEA have different effects on BRS. This is associated with an altered haemodynamic behaviour after E-CEA and C-CEA, respectively. These findings are likely the result of carotid sinus nerve interruption during E-CEA and preservation with C-CEA.

Quantitative high-field diffusion tensor imaging of cerebral white matter in asymptomatic high-grade internal carotid artery stenosis.

BACKGROUND: Recently, several studies using diffusion-sensitized MRI reported changes in patients with high-grade internal carotid artery stenosis (ICAS) suggestive of subtle brain tissue damage. We used diffusion tensor imaging (DTI) to investigate the microstructural cerebral white matter integrity in asymptomatic patients with high-grade ICAS. METHODS: In 15 asymptomatic patients with unilateral high grade (>70%) ICAS, we used 3T MRI including DTI. We used a region-of-interest approach comparing quantitative DTI metrics between both hemispheres including the so-called border zones. MR images were also assessed for periventricular white matter lesions (PWML) as well as collaterals via the circle of Willis. RESULTS: There was no significant intraindividual difference of fractional anisotropy or mean diffusivity values between the hemispheres for any region. PWML was graded 0° in 6 patients, I° in 9 and II° in 2. CONCLUSIONS: In clinically asymptomatic patients with high-grade unilateral ICAS, there was no difference between the DTI parameters of the affected and the unaffected hemisphere. These findings contrast with other studies in asymptomatic high-grade ICAS, which is likely due to patient selection. These findings argue against concomitant chronic tissue integrity changes and implicate the benignity of asymptomatic carotid artery disease in individual patients.

First presentation of pyoderma gangrenosum in a patient with partial immunoglobulin A deficiency.

We describe the case of a 58-year-old female with an intensely painful and rapidly enlarging necrotic cutaneous ulcer to the right shin on a background of partial immunoglobulin A deficiency (IgAD). She was seen by various healthcare professionals and managed with upscaling antibiotics for cellulitis requiring an inpatient hospital stay. The dermatology team made a clinical diagnosis of ulcerative Pyoderma Gangrenosum (PG) on assessing the patient 13 days post-onset of symptoms. The patient responded dramatically to steroids and oral tetracycline. This case highlights the unusually described association between PG and IgAD as well as the diagnostic challenge seen in patients presenting with PG.

Assessment of patients' satisfaction in carotid surgery under local anaesthesia by psychometrical testing--a prospective cohort study.

METHODS: Between July 2008 and December 2008 102 consecutive patients undergoing CEA under local anaesthesia (LA) were prospectively evaluated. All patients were psychometrically assessed by the Hospital Anxiety and Depression Scale (HADS), the EuroQol and the Heidelberg peri-anaesthetic questionnaire (HPQ). Furthermore technical issues of cervical plexus block were assessed. RESULTS: Multivariate analysis with an HPQ sum-score of 98 points as a cut-off level for reduced patients' satisfaction demonstrated that HADS-D scores of >9 (OR: 7.228; p = 0.003), insufficient intra-operative pain control (OR: 3.264; p = 0.0322) and complications due to plexus anaesthesia (OR: 3.794; p = 0.0370) were associated with a low patients' satisfaction in carotid surgery under LA. CONCLUSION: The efficacy of the plexus blockade in terms of pain control and side effects affects patients' satisfaction in carotid surgery under LA. When choosing LA for patients undergoing carotid endarterectomy altered states of anxiety and mood reduce satisfaction in carotid surgery under LA and might compromise patients' suitability for LA.

[Vascular surgery in the elderly - recommendations for clinical practice]. / Gefäßchirurgie im Alter - Handlungsempfehlungen für die chirurgische Praxis.

Due to the increasingly aging populations of the industrialised countries, the prevalence of vascular disorders is increasing, with an emerging patient subgroup of 80  years and older (octogenarians), often multi-morbid with an increased risk of anaesthesiological and surgical complications. This review article presents evidence-based indications for vascular surgery in the elderly (> 80  years), and the influence of advanced age on surgical results. Guidelines for daily practice were drawn from a thorough analysis of current treatment recommendations for three vascular disorders (carotid artery stenosis, abdominal aortic aneurysm, and peripheral arterial disease) with the aim of assisting the primary care physician in deciding upon the therapeutic management. In summary, evidence indicates that CEA (carotid endarterectomy) is the gold standard therapy for carotid artery stenosis, as opposed to the "best medical treatment" and CAS (carotid artery stenting). With suitable morphology of the aneurysm, endovascular aneurysm repair (EVAR) is the therapy of choice for abdominal aortic aneurysm (AAA). In elderly patients unfit for open repair and with a life expectancy of less than 4  years, EVAR does not offer any survival benefit compared with no intervention. In such patients, conservative therapy should be taken into consideration. Due to the significantly reduced life expectancy after a major amputation, the value of infrainguinal revascularisation is high, with the exception of patients aged > 90  years.

Drugs with blocking effects on the renin-angiotensin-aldosterone system do not improve endothelial dysfunction long-term in hypertensive patients.

In essential hypertension, endothelial dysfunction has been documented many times and correlates with prognosis. The influence of the renin-angiotensin-aldosterone system (RAAS) on endothelial dysfunction has also been studied. The present study investigated the duration of the effects of RAAS-blocking drugs on endothelial function in 44 consecutive, never-treated, outpatients with mild to moderate hypertension. Patients (11 per group) received an angiotensin receptor blocker (ARB; irbesartan 300 mg/day or valsartan 160 mg/day) or an angiotensin-converting enzyme inhibitor (ACEi; fosinopril 10 mg/day or quinapril 20 mg/day). If target blood pressure (< 140/90 mmHg) was not achieved, 12.5 mg/day hydrochlorothiazide was added. Endothelial function, assessed by measuring brachial artery diameter, did not change significantly after 6 weeks, 1 year or 3 years of treatment in any group. Across all groups, endothelium-dependent and -independent vasodilation increased significantly after 6 weeks but, after 1 year, decreased below baseline and was at a similar level after 3 years; groups did not differ significantly. Both ACEi and ARB had similar effects on endothelial function; improvement occurred at the start of treatment but was not maintained. Endothelial dysfunction may be a resistant or irreversible feature of hypertension, requiring high doses of antihypertensive drugs and above-average patient compliance.

Effect of different egg storage times on some egg quality characteristics and hatchability of pheasants (Phasianus colchicus).

In this study, some quality characteristics and hatchability characteristics of 1 to 2, 3 to 4, 5 to 6, 7 to 8, 9 to 10, 11 to 12, and 13 to 14 d stored pheasant eggs were investigated. Although it was determined that the effect of storage time on egg weight, shape index, and albumen weight was not significant, the effect of storage time on eggshell weight, shell thickness, yolk weight, albumen index, yolk index, Haugh unit, shell percentage, albumen percentage, and yolk percentage was significant (P<0.05). It was determined that prolonged storage time caused a decrease in the albumen index and Haugh unit value but an increase in the yolk index of pheasant eggs. There was no positive or negative effect of storage time on the fertility rates and hatchability of fertile eggs, but there was a negative effect of storage time on hatchability on d 8 (P<0.05). Pheasant eggs should not be stored more than 8 d.

A two-stage neural spiking model of visual contrast detection in perimetry.

Perimetry is a commonly used clinical test for visual function, limited by high variability. The sources of this variability need to be better understood. In this paper, we investigate whether noise intrinsic to neural firing could explain the variability in normal subjects. We present the most physiologically accurate model to date for stimulus detection in perimetry combining knowledge of the physiology of components of the visual system with signal detection theory, and show that it requires that detection be mediated by multiple cortical cells in order to give predictions consistent with psychometric functions measured in human observers.

Comparison of preoperative and postoperative anterior segment measurements with Pentacam in horizontal muscle surgery.

PURPOSE: To evaluate the effect of horizontal muscle surgery (recession or recession plus resection) on the anterior chamber parameters in patients after strabismus surgery. METHODS: The Scheimpflug of 18 eyes of 12 patients with horizontal deviations were recorded just before surgery and 1 month after surgery. The power of anterior surface of cornea in horizontal and vertical axis, thinnest corneal thickness, anterior chamber depth, anterior chamber volume, and cornea volume were analyzed. The clinical characteristics of patients, the size of the deviations, the surgical doses, and observed responses to surgery were reviewed. RESULTS: There were six male and six female patients with an average age of 11.4 years (range, 4 to 22 years). Mean preoperative deviation was 47.91 PD (range, 20 to 75 PD), eight patients had esotropia with 57.5 PD average deviation (range, 40 to 75 PD), and four patients had exotropia with 28.75 PD average deviation (range, 20 to 35 PD). Of these 18 eyes, 12 eyes had horizontal muscle recession and 6 eyes had recession plus resection surgery. At the end of 1 month, three patients were orthophoric and eight patients had residual deviations varying between 16 and 35 PD. Preoperative and postoperative comparison of the whole study group documented insignificant changes in anterior chamber parameters and in keratometer readings. However, after dividing patients into two groups-recession or recession plus resection group-only one parameter, anterior chamber volume, was significantly reduced in recession plus resection group. CONCLUSIONS: Patients with strabismus who undergo recession plus resection procedure are prone to change in anterior chamber volume. Study with larger groups and long follow-up is necessary for clearer documentation of alterations at anterior chamber parameters.

Comparison of long-term results of carotid endarterectomy for asymptomatic carotid artery stenosis.

This article summarizes the current study situation on treatment of asymptomatic carotid artery stenosis and discusses the evidence situation in the literature. The 10-year results of the ACST study have shown that in comparison to conservative treatment, carotid endarterectomy (CEA) has retained a positive long-term effect on the reduction of all forms of stroke. All multicenter randomized controlled trials comparing CEA with carotid artery stenting (CAS) and, in particular the SAPHIRE and CAVATAS studies, have in common that despite a basic evidence level of Ib, the case numbers of asymptomatic patients are too small for a conclusive therapy recommendation. In the overall assessment of the CREST study the resulting difference in the questionable endpoint of "perioperative myocardial infarction" in favor of the CAS methods, could not be confirmed for exclusively asymptomatic patients. In the long-term course of the CREST study, both methods were classified as equivalent, even when the 4­year results of periprocedural and postprocedural stroke rates in the separate assessment of the asymptomatic study participants clearly favored the CEA. The results of the ACST-1 study showed an equivalent effect of both treatment methods with respect to all investigated endpoints; however, the unequal sizes of the groups in addition to the statistically insufficient case numbers put a question mark on the validity of the study results. The results of the ASCT-2 and CREST-2 studies are to be awaited, which also investigate the significance of "CEA versus CAS" (ASCT-2) and "CEA/CAS + best medical treatment (BMT) versus BMT alone" in only asymptomatic stenoses. The current S3 guidelines allow operative therapy to be considered in patients with a 60-99% asymptomatic carotid artery stenosis, because the risk of stroke is statistically significantly reduced.

[Postoperative blood pressure alterations after carotid endarterectomy : Implications of different reconstruction methods]. / Postoperative Blutdruckschwankungen nach Karotisendarteriektomie : Implikationen der verschiedenen Rekonstruktionstechniken.

BACKGROUND: Postoperative blood pressure alterations after carotid endarterectomy (CEA) are associated with an increased risk of morbidity and mortality. OBJECTIVE: To outline the influence of the two commonly used surgical reconstruction techniques, conventional CEA with patch plasty (C-CEA) and eversion CEA (E-CEA), as well as the innovative carotid sinus-preserving eversion CEA (SP-E-CEA) technique on postoperative hemodynamics, taking the current scientific knowledge into consideration. METHODS: Assessment of the current clinical and scientific evidence on each operative technique found in the PubMed (NLM) database ranging from 1974 to 2017, excluding case reports. RESULTS: A total of 34 relevant papers as well as 1 meta-analysis, which scientifically dealt with the described topic were identified. The results of the studies and the meta-analysis showed that E­CEA correlates with an impairment of local baroreceptor functions as well as with an elevated need for vasodilators in the early postoperative phase, whereas C­CEA and SP-E-CEA seem to have a more favorable effect on the postoperative blood pressure. CONCLUSION: The CEA technique influences the postoperative blood pressure regulation, irrespective of the operative technique used. Accordingly, close blood pressure monitoring is recommended at least during the postoperative hospital stay. Further studies are mandatory to evaluate the importance of SP-E-CEA as an alternative to the classical E­CEA.

[Hybrid operating rooms versus conventional operating rooms : Economic comparisons in vascular surgery using the example of endovascular aneurysm repair]. / Hybridoperationssaal vs. konventioneller Operationssaal : Betriebswirtschaftliche Gegenüberstellung in der Gefäßchirurgie am Beispiel der endovaskulären Aneurysmachirurgie.

BACKGROUND: With changing treatment modalities in vascular surgery towards incorporating more endovascular solutions, increased numbers of hybrid operating theatres are being introduced to meet the sterility and imaging quality requirements. These cost-intensive acquisitions however have never been evaluated from an economic perspective. In this study we evaluated cost-relevant parameters before and after the introduction of a hybrid operating room using the example of endovascular aneurysm repair (EVAR) performed in patients with abdominal aortic aneurysms (AAA). METHODS: Retrospective analysis of prospectively collected data. The 4­year period before the introduction of a hybrid operating room were compared with the 4­year period following introduction. Between 2007 and 2010, 97 EVAR procedures were performed before the implementation of a hybrid operating room and 50 EVAR procedures were performed with a hybrid operating room (2012-2015). We evaluated process cost-relevant parameters (operating time) and diagnosis-related group (DRG) parameters (case load, case mix, case mix index). RESULTS: The operating time was significantly reduced on average by 23.5 min (120 min [102-140] vs. 96.5 min [90-120]; p < 0.0001) with a hybrid operating room. This led to a reduction in costs of 276.17 EUR for an EVAR procedure. The case load of EVAR increased from 308 cases from 2007-2010 to 380 cases from 2012-2015 . The associated case mix also increased from 1580 to 1986 points. The total number of case mix points of all managed operative interventions in the operating theatre before and after conversion to a hybrid operating room grew significantly by 17.33% from 8420 to 9880 (p < 0.03) in the compared time periods. CONCLUSION: With detailed, demand-oriented planning, a hybrid operating room can have a favourable economic effect due to a reduction of operating time and the overall lowering of process costs. Thus a refinancing in the long-term is feasible. In addition, this can lead to an increase in the total number and complexity of endovascular procedures.

Modeling the sensitivity to variability relationship in perimetry.

PURPOSE: Studies in glaucoma patients show that standard automated perimetry results increase in variability as sensitivity decreases. However, the reasons for this change are unclear. This study presents the principle of Divergent Dysfunction as a possible explanation for this change in variability, and incorporates it into a model that can be used to simulate perimetry. METHODS: A computer program was written to simulate visual field test results based on the model, using a Full Threshold testing strategy. The validity of the simulation was tested by comparing it with normal sensitivity values, and with test-retest data from 63 participants evaluated five times each over the course of 1 month. The effect on the simulated data of varying parameters of the model was investigated, such as changing the magnitude of variability and the percentages of false positive and negative responses. RESULTS: The correlation between subject and simulated test-retest data was 0.987. Several factors were found to affect the sensitivity-variability relationship for the simulated data, most notably the rate of sensitivity decline, the percentage of false positives, and the starting luminance of the test procedure. CONCLUSIONS: The principle of Divergent Dysfunction presented here provides a plausible explanation for the sensitivity-variability relationship for standard automated perimetry in glaucomatous eyes. The model and resultant simulation program aim to provide an intuitive demonstration of the principle, which can also be used to examine the effectiveness of different testing strategies. These findings have great implications for future clinical research.

Heart rate variability in diabetes patients.

Diabetes mellitus can cause cardiovascular autonomic neuropathy and is associated with increased cardiovascular deaths. We investigated cardiovascular autonomic neuropathy in diabetics and healthy controls by analysis of heart rate variability. Thirty-one diabetics and 30 age- and sex-matched controls were included. In the time domain we measured the mean R - R interval (NN), the standard deviation of the R - R interval index (SDNN), the standard deviation of the 5-min R - R interval mean (SDANN), the root mean square of successive R - R interval differences (RMSSD) and the percentage of beats with a consecutive R - R interval difference > 50 ms (pNN50). In the frequency domain we measured high-frequency power (HF), low-frequency power (LF) and the LF/HF ratio. Diabetes patients had lower values for time-domain and frequency-domain parameters than controls. Most heart rate variability parameters were lower in diabetes patients with chronic complications than in those without chronic complications.

Genetic polymorphisms and endothelial dysfunction in patients with essential hypertension: a cross-sectional case-control study.

BACKGROUND: Both in animal models and humans an association between endothelial constitutive nitric oxide synthase (ecNOS) gene polymorphism and the development of hypertension has been found. However, the relation between ecNOS polymorphism and endothelial function in patients with hypertension has not been systematically studied. Genes of the renin-angiotensin system include the angiotensin-converting enzyme (ACE) gene, and the angiotensin II type 1 receptor (ATIR) gene, and have been associated with essential hypertension. However, no consistent data are available about the relation between polymorphisms of these genes and the presence of endothelial dysfunction in such patients. OBJECTIVES: To assess the presence of genetic polymorphisms and of endothelial dysfunction in patients with essential hypertension. To determine the effects of gene polymorphisms on endothelial dysfunction in these subjects. METHODS: In 129 patients with essential hypertension and the same number of age-matched controls polymorphisms of the ecNOS gene, ACE gene, and AT1R gene were analysed by polymerase chain reactions. Endothelial function was assessed by maximal endothelial dependent vasodilation in response to reactive hyperaemia using high resolution ultrasound examinations of the brachial arteries. To assess correlation between genetic markers, endothelial function, and the presence of hypertension both univariate and multivariate analyses were used including Pearson's and Spearman's correlation coefficients, and multiple logistic regressions. RESULTS: The size of endothelium-dependent vasodilation between patients and controls differed by 16% (p<0.02). However, the presence of genetic polymorphisms of the ecNOS, ACE, and AT1R genes did not significantly differ between patients and controls. Neither were there any statistically significant differences in endothelial function between various genotypes of the three genes. This was so for both the patients and the controls, although in all of these comparisons the controls overall displayed a slightly better endothelial function than the patients did. Multiple regression analysis with endothelial dysfunction as dependent and the presence of gene polymorphisms as independent variables did not reveal any significant correlation either. CONCLUSION: A significant relation between endothelial dysfunction and essential hypertension was demonstrated. However, no relations between genetic markers and the presence of essential hypertension or between endothelial dysfunction and genetic markers were established. The failure of our study to demonstrate the latter may be due to confounders. Also, other genes may be more important in the pathogenesis of endothelial dysfunction and essential hypertension. The current study underscores that endothelial dysfunction and hypertension are not simple genetic disorders, and that they are, essentially, multicausal.

Cross-flow determination by transcranial Doppler predicts clamping ischemia in patients undergoing carotid endarterectomy.

AIM: Aim of the paper was to assess the reliability of preoperative cross-flow determination by transcranial Doppler measurement (TCD) to detect clamping ischemia in patients undergoing carotid endarterectomy with selective shunting. METHODS: Retrospective one-to-one matched-pair analysis of 72 patients undergoing carotid endarterectomy with preoperative TCD scanning. Matching criteria were gender, degree of contralateral stenosis and the type of stenosis (asymptomatic or symptomatic). RESULTS: Patients in need for a secondary shunt insertion had significantly less cross-flow in preoperative TCD measurement (N.=14; 38.89%) compared to the control group (N.=32; 88.89%: P=0.0001%). The sensitivity of the cross-flow determination to predict clamping ischemia was 88.9%, the specificity 61.1%. The risk of developing a clamping ischemia in the absence of a cross-flow was 12 fold higher (OR: 12.6; 95% CI: 3.7-43.3). The existence of circulatory impairment of the MCA was associated with the presence of a collateral flow in the ACoA (OR 3.21; P=0.0531; likelihood ratio test 0.0481). Other factors like renal insufficiency, the degree of stenosis or the stump pressure showed no association with a cross-flow of the ACoA in a multivariate model. CONCLUSION: TCD scanning is highly reliable to detect cross-flow prior to carotid surgery and thus helpful to identify patients at risk for clamping ischemia and need for shunting.