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Biomedical subjects

M Aschwanden

Publications and source records attributed to M Aschwanden.

At least 19 recordsLinked to original sources
PubMed2006

Quality of life improvement after hospital- based rehabilitation or home-based physical training in intermittent claudication.

BACKGROUND: The magnitude of potential changes in Quality-of-Life (QoL) after structured institution-based or home-based peripheral arterial disease (PAD) rehabilitation programs are largely unknown at present. This pilot study provides first QoL data after PAD rehabilitation or a home-based PAD training. PATIENTS AND METHODS: In a non-randomized, open-label pilot study three groups of out-patients were compared: group 1 (n = 18) PAD rehabilitation; group 2 (n = 17) PAD rehabilitation + clopidogrel 75 mg once daily; group 3 (n = 20) home-based training. The training period was 3 months, which was followed by a 3-month observation phase (without prescribed training). The institution-based rehabilitation program consisted of 3 training hours per week whereas patients training at home were instructed to walk for 1 hour per day on an outdoor track. QoL assessment was performed using MOS SF-36, PAVK-86 and PAD-WIQ questionnaires. RESULTS: At baseline background variables, demographics and claudication distances were comparable between groups. After three months of training the percentage changes for the initial and the absolute claudication distance (ICD, ACD) for groups 1, 2, and 3 amounted to 164%, 201%, 44% (ICD) and 83%, 131%, 5% (ACD), respectively. Statistically significant QoL improvements were recorded for physical functions, pain and disease related anxiety in all three study groups; statistically significant inter-group differences were not found. CONCLUSIONS: In sharp contrast to the development of the claudication distances the improvement in QoL, found after 3 months of training, was comparable and not consistently different between the groups.

Aged↗
PubMed2006

Efficient haemodialysis despite complete central venous thrombosis.

Two cases with a fully functional haemodialysis access, in spite of complete thrombotic occlusion of the ipsilateral subclavian and/or brachiocephalic vein are reported. The coincidentally detected complete venous occlusions may indicate that occult venous stenosis or thrombosis is more frequent than generally assumed. In order to avoid deterioration of the haemodynamic situation interventions may be withheld unless clinical problems related to a diminished outflow occur.

Aged↗
PubMed2006

Duplex sonography after living donor kidney transplantation: new insights in the early postoperative phase.

AIM: Vascular complications of kidney transplantation, including transplant vein thrombosis, are relevant causes for graft loss in the early postoperative phase. However, duplex flow characteristics after living renal transplantation are widely unknown. Aim of the study was to assess renal perfusion in the postoperative period with special emphasis on the renal vein. METHODS: 22 consecutive kidney graft recipients and their donors were included and prospectively followed up for three months. The following Doppler parameters were collected: in the donor before operation: the intrarenal resistive index (RI), in the recipient after transplantation and at one and three months: the intrarenal RI, peak flow velocities and area under the curve in the renal vein, as well as peak systolic velocities of the iliac and renal artery. RESULTS: None of the 22 transplants failed due to vascular complications. Highest median venous (92 cm/s [range 22-211]) and arterial peak velocities (271.5 cm/s [141.5-458]) were observed close to the anastomosis immediately after transplantation. During follow-up, flow parameters significantly decreased at three months (44.3 cm/s [13.3-156.9] and 186.8 cm/s [105.5-267.5]). The RI decreased from donor to recipient at the day of operation due to tachycardia (0.65 to 0.60; P = 0.06). After correction for heart rate, the RI was stable during follow-up. CONCLUSIONS: Initial high peak velocities in conjunction with stable resistive indices in a cohort, free of vascular graft complications, suggest a postoperative physiologic adaptation process rather than a relevant stenosis requiring medical intervention.

Adolescent↗
PubMed2005

Low-dose intra-arterial contrast-enhanced MR aortography in patients based on a theoretically derived injection protocol.

Multiple intra-arterial contrast agent injections are necessary during MR-guided endovascular interventions. In respect to the approved limits of maximum daily gadolinium dose, a low-dose injection protocol is mandatory. The objective of this study was to derive and apply a low-dose injection protocol for intra-arterial 3D contrast-enhanced MR aortography in patients. Injection rate (Qinj), concentration of injected gadolinium [Gd]inj and aortal blood flow rate (Qblood) were included for the theoretical evaluation of signal intensity (SI) of the arterial lumen. SI simulations were carried out at Qinj=2 versus 4 ml/s in the [Gd]inj range between 0-500 mM. Qinj and [Gd]inj with SI above the 75% threshold of the maximal SI were regarded as optimal injection parameters. [Gd]inj=50 mM and Qinj=4 ml/s were considered as optimal and were administered in five patients for 3D MR aortography. All images revealed clear delineation of the abdominal aorta and its major branches. Mean+/-SD of contrast-to-noise ratios of the abdominal aorta, common iliac and renal artery were 70.2+/-15.2, 58.6+/-12.3 and 67.4+/-12.3. Approximately seven intra-aortal injections would be permissible in patients during MR-guided interventions without exceeding the maximal dose of gadolinium.

Aged↗
PubMed2004

[Acute ischemia after intraarterial drug injection].

HISTORY AND CLINICAL FINDINGS: A 36-year-old patient presented with a severe hand ischemia after intraarterial injection of four dissolved tablets of Methylphenidate each 10 mg (Ritalin into the right radial artery. INVESTIGATIONS: Non-invasive vascular diagnostic demonstrated a normal perfusion of the radial and ulnar artery and a severe ischemia of the small vessels of the right hand. TREATMENT AND COURSE: Under suspicion of a combined vaso-spastic and thromboembolic arterial occlusion we started an intraarterial lysis therapy followed by anticoagulation with heparin and infusions of prostaglandines. Despite this therapy necroses of three fingers developed; partial amputation was followed by a good wound healing. CONCLUSIONS: Ischemia of an extremity after intraarterial injection of drugs is a vascular emergency.

Acute Disease↗
PubMed2004

Symptomatic vascular complications after vascular closure device use following diagnostic and interventional catheterisation.

BACKGROUND: Haemostatic puncture closure devices for rapid and effective hemostasis after arterial catheterisation are a comfortable alternative to manual compression. Implanting a collagen plug against the vessel wall may become responsible for other kind of vascular injuries i.e. thrombotic or stenotic lesions and peripheral embolisation. The aim of this paper is to report our clinically relevant vascular complications after Angio-Seal and to discuss the results in the light of the current literature. PATIENTS AND METHODS: We report the symptomatic vascular complications in 17 of 7376 patients undergoing diagnostic or therapeutic catheterisation between May 2000 and March 2003 at the University Hospital Basel. RESULTS: Most patients presented with ischaemic symptoms, arterial stenoses or occlusions and thrombotic lesions (n = 14), whereas pseudoaneurysms were extremely rare (n = 3). Most patients with ischaemic lesions underwent vascular surgery and all patients with a pseudoaneurysm were successfully treated by ultrasound-guided compression. CONCLUSIONS: Severe vascular complications after Angio-Seal are rare, consistent with the current literature. There may be a shift from pseudoaneurysms to ischaemic lesions.

Aneurysm, False↗
PubMed2004

Unusual cause of intermittent claudication.

Spontaneous dissection of a peripheral artery is a rare event. We report a case of a spontaneous, non-atherosclerotic and non-aneurysmal dissection limited to the external iliac artery in a 60-year-old woman who was admitted with a left calf claudication. Non-invasive examination documented signs of leg ischemia due to a floating wall dissection of the external iliac artery. After medical treatment over eight weeks the dissection membrane had been adapted to the vessel wall. A similar case of a spontaneous dissection limited to the external iliac artery, followed by a spontaneous healing has not been reported in the literature.

Aortic Dissection↗
PubMed2004

Cuff-compression of the proximal calf to reduce venous contamination in contrast-enhanced stepping-table magnetic Resonance angiography.

PURPOSE: To minimize venous overlay at the calf station in contrast-enhanced three-dimensional (3D) stepping-table magnetic resonance angiography (MRA) using a continuous cuff-compression technique during MR data acquisition. MATERIAL AND METHODS: Within 14 months, 32 patients suffering from symptomatic peripheral arterial occlusive disease (PAOD) with a bilateral ankle-brachial index (ABI) of 0.8 or below were consecutively enrolled in this study. Unilateral cuff-compression of the proximal calf was applied in the study group (n = 14). The control group (n = 18) underwent no compression. All patients underwent three-step 3D contrast-enhanced magnetic resonance angiography (3D CE-MRA) according to the institute's protocol. Venous contamination scores (vcs) at the calf station were blindly ranked by a 1 to 3 rating score (3 = major venous contamination). The vcs values of the control group were regarded as standard. Statistical significance between both groups was evaluated with a paired t test. RESULTS: Symmetric venous contamination was observed within the control group with a mean vcs of 2.2+/-0.6 on the left side and 2.2+/-0.7 on the right side with deltavcsleft-right of 0.1+/-0.2 (P>0.1). In the study group, asymmetric venous contamination was determined with vcsmean = 2.3+/-0.6 for the uncompressed side and vcsmean =1.4+/-0.5 for the compressed side and a deltavcsuncomp-comp of 0.9+/-0.5 (P<0.00005). The control group and the uncompressed side of the study group showed no significant difference in venous contamination (P > 0.1). CONCLUSION: Subdiastolic cuff-compression of the proximal calf is an easily applicable and inexpensive technique by which to reduce venous contamination of the calf station in stepping-table MR angiography and to improve evaluation of the infrapopliteal arteries.

Aged↗
PubMed2001

[The value of walking exercise in treatment of intermittent claudication].

Physical training is one of the basic measures for all patients suffering from a generalized atherosclerosis. Specific training forms for PAD patients include home-based and structured, organized physical training programs; these are discussed and the results of meta-analyses presented. Whereas the published materials available for a home-based training is non-conclusive, structured training programs will lead to a statistically significant and clinically relevant improvement of a PAD patients' functional capacity.

Humans↗
PubMed2001

Acute deep vein thrombosis: early mobilization does not increase the frequency of pulmonary embolism.

Outpatient treatment for acute symptomatic deep vein thrombosis (DVT) was shown to be safe for most patients. However, little is known whether patients treated on an outpatient basis were ambulating or predominantly resting, a factor which may be decisive for the outcome. In the present study 129 DVT patients were randomized to either strict immobilization for 4 days or to ambulate for > or = 4 hours per day under supervision in order to show, whether the old concept of temporary immobilization is superior to early mobilization or not. The DVT diagnosis was based on duplex sonography; all patients were screened for PE at baseline and at day 4 by pulmonary ventilation-perfusion scanning, and were followed up for a total of 3 months. Clinically, changes in leg circumferences and leg pain were evaluated. The frequency of PE at baseline was 53.0% and 44.9% in the immobile and the mobile groups, respectively. During the 4 days observation period new PEs were found in 10.0% and in 14.4% of the immobilized and the ambulating patients (delta 4.4%; 95% CI -0.5 to 13.8; chi2 = 0.596, p = 0.44). The occurrence of new PE was related to the presence of PE at baseline but not to other potential predictors. The magnitude of a decrease in leg circumferences and leg pain was comparable in both groups. No patient died during the 4 day observation period. The total 3 month mortality rate was 3.9% (5 patients; 2 from the immobile, 3 from the ambulating group). All 5 patient suffered from malignancies. The results of this study show in accordance with the trial hypothesis that, regarding the frequency of PE, immobilization is not superior to early mobilization, suggesting that early mobilization is safe.

Acute Disease↗
PubMed2000

[Venous cross-sectional area: measured or calculated?].

AIM: The aim of this study was to compare measured versus calculated venous cross-sectional area in healthy subjects in a standing and a lying position with normal breath-ing and during Valsalva manoeuvre. METHOD: Measurements were carried out in 30 venous segments (the common femoral vein CFV, the superficial femoral vein SFV, the greater saphenous vein GSV) of 5 healthy volunteers (4 female, 1 male) with a median age of 28.7 years (range 23.4-46.7 years) in supine and standing position, while normally breathing and during a standardised Valsalva manoeuvre. Venous diameters were measured from B-mode in longitudinal view while cross-sectional areas were planimetrically assessed from transverse B-mode as recorded on video (S-VHS). The mathematical calculation of areas followed the formula (0.5 diameter)2 x pi. All investigations were performed 3 times; mean values from these 3 measurements were used for further computation. Measurements were performed using the NIH Image 1.6 program. RESULTS: Correlation coefficients r of the calculated versus the measured venous area while normal breathing in standing and in lying subjects were: 0.92 and 0.82 in the CFV, 0.92 and 0.84 in the SFV as well as 0.98 and 0.97 in the GSV, respectively. During Valsalva manoeuvre in standing and lying subjects the correlation coefficients r amounted to: 0.94 and 0.93 in the CFV, 0.92 and 0.94 in the SFV as well as 0.99 and 0.98 in the GSV, respectively. CONCLUSIONS: In healthy volunteers measured and calculated venous cross-sectional area at rest and during Valsalva manoeuvre correlate well. Correlation is numerically better in standing compared to lying subjects while normal breathing. Calculated venous area is accurate and can be used for further calculations.

Adult↗
PubMed2000

Assessment of collateral perfusion: a pharmacodynamic study with buflomedil hydrochloride.

The aim of the study was to assess the influence of Buflomedil hydrochloride on collateral function. Ten patients with isolated superficial femoral occlusions were investigated twice by duplex sonography with measurement sites at the common femoral artery (CF) and the popliteal artery (PA). After the second scan 200 mg of Buflomedil hydrochloride were infused; the infusion was followed by a third duplex examination. Endpoints assessed included the arterial diameter (D(CF), D(PA)), the systolic peak velocity (Vmax), the mean velocity of the maximum envelope (Vmean m.e.), the intensity weighted time average mean velocity (Vmean i.w.), the maximum reverse flow velocity (Vrev), the end-diastolic velocity (Venddiast), the calculated volume flow (Q), the pulsatility and the resistance indices (PI, RI), and PI and RI based segmental damping factors (DF(PI), DF(RI)). For the CF measurement site the infusion of Buflomedil hydrochloride resulted in a significant reduction in Vrev and PI (p<0.05), whereas trends in the opposite direction (increase) were observed for both measures of Vmean and for Q (0.1<p<0.05). No significant changes were reported for the PA measurement site. DF(PI) numerically decreased (0.1<p<0.05). The pattern of changes suggest that Buflomedil hydrochloride induces collateral vasodilation and thus improves collateral function.

Adult↗
PubMed2000

The reliability of leg circumference assessment: a comparison of spring tape measurements and optoelectronic volumetry.

The purpose of this study was to compare the reliability of repeated spring tape measurements with optoelectronic volumeter measurements for the assessment of lower leg circumferences. The limb circumferences at mid-calf and ankle level of both legs were measured three times using a spring tape measure as well as an optoelectronic volumeter. In all, 30 healthy volunteers participated in the study. Test reliability and repeatability were described through the process-related and between-subject variances and variance-derived parameters such as the reliability coefficient (intraclass correlation coefficient, RC), the relative precision (RP), and the coefficient of repeatability (CR). A higher value for the RC and a lower value for the RP indicate that the test variability is predominantly due to between-subject variance and not to test process-related variance. RCs for both methods, independent of whether measurements were taken at calf or at ankle level, always exceeded 0.95. RPs were in the same order of magnitude for both methods but lower for measurements at calf than at ankle level (range: RPcalf 6.36-8.74%; range: RPankle 12.49-18.56%). CRs for both methods were low and of comparable magnitude (CR range: 4.8-7.7), although slightly smaller for the spring tape. When measurement results from the spring tape and the volumeter were compared, results achieved with the volumeter were significantly longer than those from the spring tape (p<0.05). Results from both methods were linearly in good agreement and there was no proportional bias; differences shown were due to a significant constant bias regarding the volumeter. Circumference measurements taken by spring tape and by optoelectronic volumetry are both characterized by a comparably high reliability. However, these methods cannot be used in an interchangeable way because a constant bias exists for volumetry, resulting in significantly larger circumferences compared with those measured using the spring tape.

Adolescent↗