Vertebral and internal mammary artery steal syndrome in patients with hemodialysis access.

BACKGROUND: Increased flow in the subclavian artery feeding a vascular access for hemodialysis can induce steal phenomena in the vertebral (VA) and internal mammary artery (IMA). The aim of this study was to describe the hemodynamic effects of access flow on the VA and IMA in patients with native fistulas and grafts. PATIENTS AND METHODS: Peak systolic (PSV) and end diastolic (EDV) velocity measurements of the VA, IMA and carotid arteries, as well as flow volume measurements of the subclavian artery, were performed. Flow measurements at the side of the vascular access were compared with the contralateral side. Fifty-five patients were consecutively included, most with a radio-cephalic fistula on the left arm with a mean shunt volume of 1156 ml/min. RESULTS: Pathologic flow patterns were observed in the ipsilateral VA in four patients (7.3 %); contralateral VA flow was normal in all patients. Peak systolic velocity of the VA was significantly decreased at the side of the shunt arm with a PSV of 42.6 ± 11.8 cm/s compared to 48.4 ± 15.6 cm/s contralateral (p < 0.05). The IMA flow pattern were normal in all patients. The PSV of the IMA was significantly decreased (p < 0.01) at the side of the shunt arm (87.5 ± 29.1 cm/s) compared to the non-shunt arm (95.9 ± 27.4 cm/s). CONCLUSION: We describe significant hemodynamic effects of fistulas to the vertebral and internal mammary arteries. Doppler spectral analysis of the vertebral and internal mammary arteries should be integrated in ultrasound, especially in patients with cerebrovascular or cardiac symptoms.

Acute effects of haemodialysis on central venous and arterial pressure characteristics.

AIM: Haemodynamic stability of patients during haemodialysis (HD) sessions is of pivotal importance and accurate determination of dry weight remains a challenge. Little information is available about central venous and aortic pressure during dialysis. In this pilot study we used a non-invasive technique to describe the changes in central venous pressure (CVP) during dialysis. METHODS: An ultrasound-assisted pressure-manometer was used at the cephalic vein during haemodialysis to quantify CVP. Central aortic pressure changes were assessed as aortic augmentation index and subendocardial viability ratio. Bioimpedance was applied to measure total body water, as well as extracellular and intracellular water before and after HD. Measurements were performed prior during and after 1 and 2 h on HD. RESULTS: Ten patients were included with a median age of 72 years (23-82). Haemodialysis reduced the weight by 2.0 kg, corresponding to a measured decrease in total body water of 1.9 L. The mean CVP showed a significant decrease (9.0-0.8 cmH2O; P = 0.0005) during dialysis. The significant drop in CVP was found during the first hour (9-2.8 cmH2O). Starting and stopping dialysis was reflected by a reduction of 2.6 cmH2O and a rise of 2.8 cmH2O (n.s.). Aortic augmentation index decreased from 26.1% to 21.0% (n.s.). Subendocardial viability ratio increased from 126% to 156% (P < 0.05) during HD, and decreased to 139% direct after HD (n.s.). CONCLUSION: This is the first study that illustrates a prominent reduction of CVP during the first hour of haemodialysis. Non-invasive CVP measurement is feasible during haemodialysis and adds another piece in the puzzle of factors involved in haemodynamic stability.

Markers of arterial stiffness in peripheral arterial disease.

Increased arterial stiffness results from reduced elasticity of the arterial wall and is an independent predictor for cardiovascular risk. The gold standard for assessment of arterial stiffness is the carotid-femoral pulse wave velocity. Other parameters such as central aortic pulse pressure and aortic augmentation index are indirect, surrogate markers of arterial stiffness, but provide additional information on the characteristics of wave reflection. Peripheral arterial disease (PAD) is characterised by its association with systolic hypertension, increased arterial stiffness, disturbed wave reflexion and prognosis depending on ankle-brachial pressure index. This review summarises the physiology of pulse wave propagation and reflection and its changes due to aging and atherosclerosis. We discuss different non-invasive assessment techniques and highlight the importance of the understanding of arterial pulse wave analysis for each vascular specialist and primary care physician alike in the context of PAD.

Carotid artery disease after head and neck radiotherapy.

Radiation induced atherosclerosis of the carotid artery is a clinically relevant late complication after head and neck radiotherapy. Improved long-term survival after multimodality therapy in neck malignancies result in an increased risk of carotid artery disease in patients after radiotherapy (RT). This review focuses on the current knowledge of occlusive carotid disease after head and neck radiotherapy and highlights the exceeding morphologic post-radiation vessel wall pathologies. More severe and extensive carotid artery atherosclerosis with plaque in all segments including the common carotid artery is a frequent finding after RT. Therefore, colour coded duplex ultrasound surveillance in patients after head and neck RT is recommended. Some histopathological studies indicate differences to “classical” atherosclerosis, and pathogenesis of chronic radiation vasculopathy is still under discussion.

Vascular malformations revisited.

Vascular malformations are congenital anomalies that can affect each part of the vasculature. Combined forms are common and they are often part of complex syndromes. Most malformations are diagnosed during infancy, but some get obvious only later in life. The field of vascular malformations is emerging with recently described new entities and treatments. Still, misdiagnosis is common in this field, leading to nosologic confusion and wrong treatment. Clinical evaluation and imaging are the gold standard for diagnostic confirmation. Sclerotherapy and embolization are the main treatment techniques but are also used preoperatively to reduce blood loss and shrink the lesion if surgery is planned. Despite new treatment options, especially if extensive in size or involving vulnerable structures, vascular malformations are still considered chronic diseases and cause significant morbidity. Common understanding and agreement on terminology and a multidisciplinary approach are the basis of successful treatment and long-term support for these patients. Continuing research in the field of vascular anomalies will improve knowledge and create further treatment options.

Combined and complex vascular malformations.

The correct diagnosis of vascular malformations is obtainable by clinical assessment and patient history in the majority of cases. Nonetheless, confusion in nomenclature, existence of multiple classifications and rarity of these lesions leads to misdiagnosis and related wrong treatment. This is especially the case in combined or complex vascular malformations or vascular malformations that are part of syndromes as these have overlapping clinical and imaging features. New entities in the field of vascular anomalies have been described recently like fibro-adipose vascular anomaly or central conducting lymphatic anomalies.

Increased permeability of cutaneous lymphatic capillaries and enhanced blood flow in psoriatic plaques.

INTRODUCTION: Morphological abnormalities of microvessels are described in psoriasis. However, there are conflicting data as to whether their function is also altered. OBJECTIVE: Our aim was to study the morphology and function of the lymphatic capillaries of psoriatic skin. METHODS: Morphology and permeability of initial lymphatics were studied by microlymphography and densitometry in 20 patients. Perfusion was studied by laser Doppler fluxmetry. RESULTS: Permeability of lymphatics in plaques was increased by 7.6% compared to unafflicted skin (p < 0.001). Lymphatic vessel density and the extension of dye in lymphatic networks were not significantly different between involved and uninvolved areas. Both sites showed a wide range of diameters of lymphatics. The median laser Doppler flux in plaques was increased by 144% (91-380%) compared to unaffected skin (p < 0.001). CONCLUSIONS: Increased permeability of lymphatics and increased blood flow was demonstrated in vivo in psoriatic skin lesions. These findings may reflect the local inflammatory process and may be used as markers when studying new therapeutic approaches for psoriasis.

Endovascular treatment of Angio-Seal-related limb ischemia--primary results and long-term follow-up.

OBJECTIVES: To investigate primary success rates and long term follow-up of endovascular treatment of AngioSeal-related limb ischemia. BACKGROUND: Current knowledge on optimal therapy of ischemic complications following application of AngioSeal is limited. METHODS: A single-center prospectively maintained database was retrospectively interrogated and AngioSeal-related complications requiring endovascular treatment over an 8-year-time period was identified. RESULTS: Fifteen patients fulfilling the inclusion criteria were identified, resulting in an approximated incidence of 0.26% of all devices implanted at our institution. In all cases, the complication was managed successfully in the absence of complications. Eleven patients were treated with balloon angioplasty (PTA) and four with stent implantation because of suboptimal PTA results. Twelve patients were available for noninvasive vascular follow-up examination for a median time of 40 months postinterventionally. Only two patients needed a second intervention consisting of balloon angioplasty due to symptomatic restenosis. At final follow-up all patients were asymptomatic with no relevant restenosis. CONCLUSION: Endovascular treatment for AngioSeal-related limb ischemia with or without stent implantation results in an excellent immediate and long-term clinical and hemodynamic outcome.

Nailfold capillaroscopy: Specific features in Fabry disease.

OBJECTIVE: Fabry disease is a rare X-linked disorder caused by deficiency of alpha-galactosidase A. The metabolic defect results in the progressive accumulation of globotriaosylceramide within vascular cells leading to renal, cardiac and cerebrovascular manifestations. The aim of this study was to evaluate nailfold capillaroscopy as a non-invasive diagnostic tool in Fabry disease and to characterize morphological and functional changes of the capillaries in vivo. METHODS: Twenty-five consecutive patients with Fabry disease (17 males) without enzyme-replacement therapy had been studied by fluorescence nailfold capillaroscopy. Macrocirculation of digital arteries was tested by digital pulse volume recording and patients had been asked about the presence of Raynaud phenomenon. RESULTS: Significant more bushy capillaries and clusters were present in Fabry patients (72%) compared to healthy controls (10%). No avascular fields had been seen, and in only one patient atypical architecture and in another one a giant capillary was present. Enhanced natrium-fluorescein diffusion into the pericapillary area has been observed in three male patients. Six patients (one female) reported Raynaud phenomenon of all fingers. CONCLUSIONS: In Fabry disease morphological and functional microangiopathy of nailfold capillaries is present. Furthermore, these new findings might explain, at least in part, the unusual high frequency of Raynaud phenomenon in Fabry patients, which has not been described so far. Our data suggest that capillaroscopy might be used as an additional non-invasive diagnostic tool for Fabry disease.

Cardiac biomarkers but not measures of vascular atherosclerosis predict mortality in patients with peripheral artery disease.

BACKGROUND: Peripheral artery disease (PAD) becomes more prevalent with advancing age and is associated with elevated risk of cardiovascular events and shortened life expectancy. We investigated the prognostic performance of cardiac and vascular biomarkers in a cohort of PAD patients. METHODS: A total of 95 PAD patients were enrolled (mean age 68 years, range 47 to 86 years, 73 males). Carotid intima-media thickness (cIMT), ankle brachial index (ABI), high sensitive cardiac troponin T, and N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) were measured. RESULTS: During a median follow-up time of 9.5 years, 44 patients died and 51 patients survived. Upon Kaplan-Meier survival analysis hs-TnT (P < .001) or NT-proBNP levels (P < .001) above the median but not cIMT above the median (P = .488) or ABI below the median (P < .436)were associated with reduced survival rate. Upon univariate cox regression and after adjustment for age, gender, prior cerebral artery disease, and diabetes mellitus only the association between hs-cTnT and mortality remained significant (HR 1.93, 95% CI 1.33-2.79, P < .001). In receiver operating curve analysis hs-cTnT (area under the curve [AUC]: 0.77, 95% CI: 0.67-0.87, P < .001) NT-proBNP (AUC: 0.74, 95% CI: 0.64-0.84, P < .001) as well as hs-cTnT, and NT-proBNP combined (AUC: 0.79, 95% CI: 0.69-0.88, P < .001) were superior to cIMT (AUC: 0.64, 95%, CI: 0.53-0.76, P = .022) and ABI (AUC: 0.57, 95% CI: 0.44-0.68, P = .313) in discriminating risk for mortality. CONCLUSION: hs-cTnT and NT-proBNP should be taken into account for prognosis of patients with PAD.

Predictive value of nailfold capillaroscopy in patients with Raynaud's phenomenon.

The objective of this study was to evaluate the long-term follow-up of patients with Raynaud's phenomenon (RP) and pathological nailfold capillaroscopy (NC) in order to analyse the predictive value of specific features of capillaroscopy for the development of a connective tissue disease (CTD). From 1992 to 2002, NC alone or combined with fluorescence videomicroscopy with sodium fluorescein (NaF) was performed in 1024 consecutive patients because of RP. We analysed the follow-up and pathological features of NC in all patients who had neither clinical nor serological signs of a CTD at the time of NC. Of 308 patients with neither serological findings nor clinical signs of CTD but with RP and pathological features in NC suspicious for CTD, follow-up data were available for 133 patients. An additional NaF test had been performed in 51 (38.4%) patients. After a mean follow-up of 6.5 years (range: 1-15 years), 109 patients had developed a CTD and 24 patients did not show any clinical signs or serological markers for a CTD after a mean follow-up of 8.5 years (range: 2-15 years). There were no differences in age, duration of RP or of follow-up in patients who developed a CTD compared to patients who did not. Significantly more giant capillaries (p=0.0001), avascular fields (p=0.02) and irregular architecture (p=0.0001) had been observed in patients who had developed a CTD during the follow-up of 6.5 years. The presence of giant capillaries, avascular fields and irregular architecture of nailfold capillaries is predictive for the development of a CTD in patients with RP.

Misdiagnosis of plexiform neurofibroma as venous malformation in pediatric patients.

BACKGROUND: The aim of this study was to identify Magnetic Resonance Imaging (MRI) characteristics that reliably distinguish deep plexiform neurofibromas (PNFs) from venous malformations (VMs). METHODS: A database search was conducted for patients that were referred with a vascular anomaly but had a neurofibroma instead. Clinical and imaging features of patients with venous malformations as the most common referral diagnosis were compared to those with PNFs. The imaging features of deep PNFs recorded were: anatomical location, size, morphology, margins, signal intensity and post-contrast enhancement pattern. RESULTS: Ten patients with PNFs were identified. Five patients had adequate imaging. These five patients were included in our study. There were 3 female and 2 male patients ranging in age from 10 months to 21 years. Deep PNFs were located in the cervicofacial region (N.=3), lower extremity (N.=1) and back/flank region (N.=1). The most common clinical features of all these patients were palpable mass (N.=5) and pain (N.=4). The MRI features that distinguished VMs from deep PNFs were the serpiginous morphology, relatively intermediate T-2 signal intensity and peculiar enhancement pattern without fluid-fluid levels or phleboliths and nerve root involvement. The target sign can be regularly found in PNFs, but may be also present in VMs and other vascular lesions. CONCLUSIONS: Target signs, a typical sign of PNFs may be absent and can also be found in vascular anomalies, leading to confusion in diagnosis. PNFs can be reliably distinguished from VMs on MRI based on the above mentioned features.

Blood fluidity and outcome after femoropopliteal percutaneous transluminal angioplasty (PTA): role of plasma viscosity and low platelet count in predicting restenosis.

Rheological abnormalities are well known in patients with peripheral arterial occlusive disease (PAOD). We wanted to determine whether rheological variables are related to restenosis after femoropopliteal percutaneous transluminal angioplasty (PTA). In 114 patients (62 men; median age 70 years) undergoing femoropopliteal PTA for symptomatic peripheral arterial occlusive disease (PAOD) plasma viscosity, red cell aggregation, whole blood viscosity, hematocrit, fibrinogen, platelet count, leukocytes and C-reactive protein were determined the day after the procedure and at 1, 3, and 12 months. The primary endpoint was restenosis >50% documented by duplexsonography up to 12 months. Cox proportional hazards analysis was used to assess the risk of restenosis for postinterventional values of rheological variables. Forty-eight patients (42%) developed restenosis at 12 months. Patients with restenosis had higher baseline plasma viscosity (PV) (medians, 1.71 vs. 1.65 millipascal seconds [mPa.s]; p = 0.04) and lower platelet count (224 vs. 240 x 10(3)/microl; p = 0.03) than patients without restenosis. The hazard ratio (HR; 95% CI) of incident restenosis was 9.2 (1.12-76; p = 0.03) for PV and 0.99 (0.99-1.0; p = 0.07) for PLT. When examining jointly both high PV and low platelet count (PLT), patients with PV > 1.66 mPa.s and PLT < 233 x 10(3)/microl (i.e. variables split at their respective median) had an increased risk of restenosis (log-rank test p = 0.01). Multivariate Cox proportional hazard analysis showed that plasma viscosity (p = 0.02), low platelet count (p = 0.01), lesion length (p = 0.0037) and lack of hypertension (p = 0.01) were associated with restenosis at 12 months. No associations were found between restenosis and the other rheological and inflammatory variables studied. Our data suggest that increased PV and low PLT contribute to restenosis after femoropopliteal PTA.

Long term follow-up after endovascular brachytherapy of femoro-popliteal arteries.

To perform a long term follow-up after endovascular brachytherapy (EVBT) and balloon angioplasty (PTA) regarding vessel patency and diameter. EVBT had been successfully used to decrease restenosis in short term, but long term data are lacking. Participants of a randomized study comparing EVBT and balloon angioplasty alone were invited for follow-up examination ten years after intervention. Using a standardized protocol measurement of the patency and vessel diameter was performed of femoral and popliteal arteries. 44 patients were included, 21 had been treated with EVBT and 23 had received PTA alone. Target lesion patency was similar between the two groups (90.5% vs. 87.0%). Vessel diameter of the target lesion was significantly greater in the EVBT group (6.4 mm, range 3.9-9.9) compared to the controls (5.0 mm, range 3.1-7.4; p = 0.002). Ten years after EVBT of femoro-popliteal arteries vessel diameter is significantly increased whereas patency rate is not different compared to angioplasty alone.

Severe lymphatic microangiopathy in Fabry disease.

BACKGROUND: Lymphedema has been described in a few cases of Fabry disease. The etiology of lymphedema in Fabry disease is unknown. The aim of the study was to evaluate morphology and function of lymphatic microvessels in this disease. METHODS AND RESULTS: In five male patients with Fabry disease, the initial lymphatic microvessels of the skin were studied in vivo, using a nearly atraumatic technique of fluorescence microlymphography and measurement of lymph capillary pressure. In addition, five female patients heterozygous for Fabry disease and 12 healthy controls were studied. The maximum spread of the fluorescent macromolecular dye into the network of superficial skin lymphatics was increased in the three male patients presenting with lymphedema (25, 26, and 45 mm, respectively). In the two male patients without swollen legs, the maximum spread of the dye was 3 and 7 mm, respectively, and in the female patients 8.8 mm (range, 4-17 mm), whereas in the healthy controls it reached only 4.3 mm (range, 1-7 mm). Fragmentation of the microlymphatic network was found in all patients, but not in controls. In controls, the diameter of the microvessels varied in a very narrow range (45-75 microm); in patients, the range was 15-150 microm. In patients with lymphedema, microlymphatic hypertension was present. CONCLUSION: In patients with Fabry disease severe structural and functional changes of the initial lymphatics of the skin are present.

Platelet aggregation and blood rheology in severe sepsis/septic shock: relation to the Sepsis-related Organ Failure Assessment (SOFA) score.

Abnormalities in blood rheology and platelet dysfunction might play a role in the pathogenesis of multiple organ failure in septic patients by reducing microvascular blood flow. To determine whether alterations in blood rheology and in platelet function are related to the severity of organ dysfunction, we prospectively studied plasma fibrinogen, red cell aggregation, plasma viscosity, hematocrit, whole blood viscosity and platelet aggregation in relation to the Sepsis-related Organ Failure Assessment (SOFA) score in 34 consecutive patients with severe sepsis/septic shock. We found that patients had higher plasma fibrinogen, red cell aggregation and plasma viscosity (p < 0.01), but lower hematocrit, whole blood viscosity and ADP-induced platelet aggregation than controls (p < 0.01). Platelet aggregation (p < 0.01), but not other rheological variables, were inversely related to the SOFA score. Only platelet count was linked to poor clinical outcome (p < 0.05). We conclude that blood rheology and platelet function are severely altered in patients with severe sepsis/septic shock. Our findings suggest progressive platelet dysfunction with advancing severity of the disease. Platelet dysfunction might play a more important role in the pathogenesis of the multi organ dysfunction syndrome than abnormalities in blood rheology.

Small dense low density lipoprotein particles are associated with poor outcome after angioplasty in peripheral artery disease.

PURPOSE: In patients suffering from symptomatic peripheral artery disease (PAD), percutaneous revascularization is the treatment of choice. However, restenosis may occur in 10 to 60% in the first year depending on a variety of factors. Small dense low density lipoprotein (sdLDL) particles are associated with an increased risk for cardiovascular events, but their role in the process of restenosis is not known. We conducted a prospective study to analyze the association of sdLDL particles with the outcome of balloon angioplasty in PAD. The composite primary endpoint was defined as improved walking distance and absence of restenosis. METHODS: Patients with angiographically documented PAD of the lower extremities who were scheduled for lower limb revascularization were consecutively recruited for the study. At baseline and at three month follow-up triglyceride, total cholesterol, LDL size and subclasses and HDL cholesterol and ankle-brachial index (ABI) were measured. Three months after the intervention duplex sonography was performed to detect restenosis. RESULTS: Sixty-four patients (53% male) with a mean age of 68.6±9.9 years were included. The proportion of small- dense LDL particles (class III and IV) was significantly lower (33.1±11.0% vs. 39.4±12.1%, p = 0.038) in patients who reached the primary end-point compared with those who did not. Patients with improved walking distance and without restenosis had a significantly higher LDL size at baseline (26.6±1.1 nm vs. 26.1±1.1 nm, p = 0.046) and at follow-up (26.7±1.1 nm vs. 26.2±0.9 nm, p = 0.044) than patients without improvement. CONCLUSIONS: Small-dense LDL particles are associated with worse early outcome in patients undergoing percutaneous revascularization for symptomatic PAD.

Pressure indices in peripheral arterial disease assessed by infrared photosensors.

Ankle-brachial index (ABI) assessment by Doppler is operator dependent and limited in calcified arteries. For the detection of peripheral arterial disease (PAD), we evaluated ABI and toe-finger (ToFi) pressures by infrared (IR) sensors at the digits and compared with standard Doppler (Doppler-ABI) in 100 patients with PAD and in 15 controls. Pressure indices were obtained in 86% for Doppler-ABI, 82% for IR-ABI, and 94% for IR-ToFi (P < .01). According to Bland-Altmann analysis, IR-ABI and Doppler-ABI are exchangeable (limits of agreement [loa] -0.30; 0.30, bias -0.003, 95% confidence interval [CI] -0.02; 0.02), whereas IR-ToFi was not (loa -0.23; 0.61, bias of 0.2, 95% CI 0.16; 0.23). The IR-ToFi revealed the best inter- and intrarater agreement (0.92/0.98) followed by IR-ABI (0.74/0.98) and Doppler-ABI (0.66/0.89). Ankle-brachial arterial pressure index can be assessed by IR photosensors. Although toe-finger index is not exchangeable with standard Doppler, it will need further exploration to define its value for the diagnosis of PAD due to its excellent inter- and intrarater agreement.