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W P Mali

Publications and source records attributed to W P Mali.

At least 19 recordsLinked to original sources
PubMed2003

[Hospital-wide vascular screening program at the University Medical Center, Utrecht: prevalence of risk factors and asymptomatic vascular disease from 1996 to 2002].

OBJECTIVE: Tracing and treating cardiovascular risk factors in patients with arterial vascular disease and in patients with high risk of developing vascular diseases. DESIGN: Descriptive. METHOD: In September 1996 at the University Medical Center Utrecht, the Netherlands, a vascular screening and prevention programme was started for newly referred patients aged between 18 and 79 years presenting with one or more of the following: coronary artery disease, cerebrovascular disease, peripheral arterial disease, hypertension, diabetes mellitus or lipid disorders. In all patients, risk factors for developing (new) vascular diseases were assessed and non-invasive vascular diagnostics aimed at finding asymptomatic vascular disease were done. RESULTS: Between 1 September 1996 and 31 October 2002, 3075 patients took part in the screening programme. Within the various patient groups and often despite treatment, there was a high prevalence of hypertension, smoking, dyslipidaemia, hyperhomocystemia and overweight. In patients with peripheral artery disease, carotid artery stenosis > or = 50% was detected in 17% and an aneurysm of the abdominal aorta in 5%. In patients presenting with diabetes mellitus, hypertension or lipid disorders the prevalence of asymptomatic arterial disease was 1-5%. Asymptomatic vaso-dilatory disease in particular was uncommon. CONCLUSION: A hospital-wide vascular screening and prevention programme for a wide range of high-risk vascular patients was shown to be feasible and resulted in the detection of risk factors and asymptomatic arterial disease. It is a reliable starting point for actual risk intervention. More attention should be paid to treating existing risk factors.

Adolescent↗
PubMed2003

[Percutaneous vertebroplasty in the treatment of osteoporotic vertebral compression fractures: review of the literature].

OBJECTIVE: To determine the effectiveness and safety of percutaneous vertebroplasty for the treatment of osteoporotic vertebral compression fractures as published in the scientific literature. DESIGN: Literature review. METHOD: Medline and the Cochrane library were searched with the terms 'percutaneous vertebroplasty', 'vertebral compression fractures', 'osteoporotic' and 'osteoporosis'. Criteria for inclusion were: (a) the studies had to have been published in the period January 1985-August 2002, (b) the study population had to include at least 10 patients, (c) the patients had to have been treated with percutaneous vertebroplasty, and (d) the diagnosis had to have been 'osteoporotic vertebral compression fracture'. RESULTS: Twelve studies met the inclusion criteria. Pain relief was seen in 60%-100% of the patients within the first 24 hours and this result improved to 78-100% in the long term (maximum 4 years). The complications immediately after the procedure were related to cement leakages and were mostly of no clinical consequence. Serious complications such as pulmonary embolism were rare. In the long term, percutaneous vertebroplasty was associated with an increased risk of fractures in the adjacent vertebrae. CONCLUSION: Percutaneous vertebroplasty seems to be effective and safe in the treatment of osteoporotic vertebral compression fractures. A prospective randomised intervention study has, however, not yet been performed. For the time being, percutaneous vertebroplasty should be reserved for carefully selected patients in whom conservative therapy has not produced results.

Adult↗
PubMed2001

Collateral ability of the circle of Willis in patients with unilateral internal carotid artery occlusion: border zone infarcts and clinical symptoms.

BACKGROUND AND PURPOSE: The circle of Willis is regarded as the major source of collateral flow in patients with severe carotid artery disease. The purpose of the present study was to assess whether the presence of border zone infarcts is related to the collateral ability of the circle of Willis in symptomatic (transient ischemic attack, minor stroke) and asymptomatic patients with unilateral occlusion of the internal carotid artery (ICA). METHODS: Fifty-one patients (35 symptomatic, 16 asymptomatic) and 53 control subjects were investigated. Patients had unilateral occlusion of the ICA and contralateral ICA stenosis between 0% and 69%. The directions of flow, on the side of the ICA occlusion, and the size of the component vessels in the circle of Willis were investigated with MR angiography. RESULTS: On average, 92% of the patients without border zone infarcts (n=26) had willisian collateral flow compared with 60% of patients with border zone infarcts (n=25; P<0.05). This increase in collateral flow was caused by the high prevalence of collateral flow via the posterior communicating artery in patients without border zone infarcts (50% versus 12%; P<0.05). No statistically significant relation was found between the pattern of collateral flow via the circle of Willis and the presence of clinical symptoms. Nevertheless, asymptomatic patients with ICA occlusion demonstrated an increased diameter of the anterior communicating artery (P<0.05). CONCLUSIONS: In patients with unilateral ICA occlusion, the presence of collateral flow via the posterior communicating artery in the circle of Willis is associated with a low prevalence of border zone infarcts. Asymptomatic patients with an ICA occlusion do not have an increased collateral function of the circle of Willis.

Adult↗
PubMed2001

[Spiral computed tomographic angiography as a substitute for intra-arterial angiography of aorta and its branches].

Until recently, intra-arterial angiography was the diagnostic method of first choice when pathology of the aorta or its branches was suspected. A disadvantage of this technique is that only the lumen of spaces with blood flow can be visualised and that the soft tissue surroundings remain (partly) invisible. Spiral computer tomographic angiography (CTA) has some major advantages compared with conventional angiography. The technique is less invasive and faster. Also, the soft tissue is imaged by CTA. In addition, computer reconstructions allow viewing from all directions without the limitations of overprojection. Spiral CTA is a suitable technique for imaging the thoracic part of the aorta: in case of dissection if transoesophageal echography is not available, in case of an aneurysm to determine the diameter and in case of rupture as a highly sensitive but not very specific examination technique. For imaging of the abdominal part of the aorta, spiral CTA may be considered. In case of an aneurysm or a possible rupture of this part of the aorta it is then possible to visualize the operation area and to choose the optimal approach. For the exclusion of stenoses in mesenteric arteries or in renal arteries, spiral CTA offers the advantage of non-invasivity. The technique is less suitable for demonstration of these stenoses and does not allow immediate intervention.

Adult↗
PubMed2001

[Diagnostics in clinically occult, radiologically suspect breast lesions more often surgery than needle diagnostics with image monitoring].

OBJECTIVE: To inventory the diagnostic methods used in patients with clinically occult, radiologically suspect breast lesions. DESIGN: Enquiry. METHOD: The departments of radiology of all Dutch hospitals were sent a list in January 2000 containing questions concerning the number of thread localizations in 1999 and the use of cytological or histological needle diagnostics with image monitoring prior to surgical intervention in clinically occult, radiologically suspect breast lesions. Of the 120 questionnaires mailed, 74 (62%) were completed and returned by clinics throughout the country. RESULTS: Fifty-one of the 74 hospitals (69%) had prior to operation carried out histological or cytological examinations and in these 51 hospitals this was done in 1743 of the 2857 lesions (61%): fine-needle aspiration cytology was performed in 1046 (/1743 = 60%; /4140 lesions in all 74 hospitals = 25%) and/or histological needle biopsy in 784 (45%; /4140 = 19%). CONCLUSION: In less than half of all non-palpable breast abnormalities non-surgical methods of diagnosis are used, histological needle biopsy less often than fine needle aspiration cytology.

Biopsy↗
PubMed2001

Quantitative analysis of vascular morphology from 3D MR angiograms: In vitro and in vivo results.

A 3D model-based approach for quantification of vascular morphology from several MRA acquisition protocols was evaluated. Accuracy, reproducibility, and influence of the image acquisition techniques were studied via in vitro experiments with ground truth diameters and the measurements of two expert readers as reference. The performance of the method was similar to or more accurate than the manual assessments and reproducibility was also improved. The methodology was applied to stenosis grading of carotid arteries from CE MRA data. In 11 patients, the approach was compared to manual scores (NASCET criterion) on CE MRA and DSA images, with the result that the model-based technique correlates better with DSA than the manual scores. Spearman's correlation coefficient was 0.91 (P < 0.001) for the model-based technique and DSA vs. 0.80 and 0.84 (P < 0.001) between the manual scores and DSA. From the results it can be concluded that the approach is a promising objective technique to assess geometrical vascular parameters, including degree of stenosis. Magn Reson Med 45:311-322, 2001.

Algorithms↗
PubMed2001

MRA of hemodialysis access grafts and fistulae using selective contrast injection and flow interruption.

MR is a potentially attractive modality for evaluating hemodialysis access anatomy and function. However, the wide range of flow rates in the hemodialysis access complicates interpretation of phase contrast, time-of-flight, and even contrast-enhanced MR angiograms. At high flow rates, signal voids may easily arise at mild narrowings or sharp-angled anastomoses. A method is proposed which visualizes hemodialysis accesses without flow artifacts. Diluted Gd-DTPA is hand-injected directly into the access, while a cuff is used to reduce and subsequently interrupt access flow. Filling of the access is monitored using a fast projection technique with complex subtraction. When filling is satisfactory, a 3D acquisition is started. The feasibility of this selective contrast-enhanced MR angiography technique is demonstrated in four Cimino-fistulae and four PTFE grafts. Magn Reson Med 45:557-561, 2001.

Arteriovenous Shunt, Surgical↗
PubMed2001

Impact of stereotactic large-core needle biopsy on diagnosis and surgical treatment of nonpalpable breast cancer.

INTRODUCTION: Stereotactic large-core needle biopsy is increasingly replacing needle-localized breast biopsy for the diagnosis of nonpalpable breast disease. In this prospective study, the impact of the introduction of this technique on diagnosis and surgical treatment of nonpalpable breast cancer was assessed in two hospitals in The Netherlands. PATIENTS AND METHODS: A total of 84 patients with nonpalpable breast cancer, diagnosed by means of stereotactic large-core needle biopsy (needle biopsy group) were compared with 80 patients diagnosed with nonpalpable breast cancer before the introduction of large-core needle biopsy. These patients were diagnosed by means of needle-localized open breast biopsy (control group). Clinical outcome measures evaluated included: duration of diagnostic and therapeutic intervals and number of surgical procedures required for complete surgical treatment. Subgroup analysis was performed for the category of microcalcifications without tissue distortion. RESULTS: For the needle biopsy group, the median interval between initial referral to the surgeon and the availability of histological diagnosis was 9 days and the interval between initial referral and complete surgical treatment was 31 days. These intervals were significantly longer for the control group (19 days and 44 days respectively); 75% of patients in the needle biopsy group were treated in a single step surgical procedure compared to 16% of the patients in the control group (67 vs 25% respectively for the subgroup). The mean number of surgical procedures required to complete surgical treatment was 1.31 for needle biopsy group vs 1.91 for the open biopsy group (1.46 vs 1.84 for the subgroup). CONCLUSION: Introduction of stereotactic large-core needle biopsy leads to a reduction of the time to diagnosis and the time to complete surgical treatment of nonpalpable breast cancer. It also reduces the number of surgical procedures required for complete surgical treatment of nonpalpable breast cancer. The benefits of large-core needle biopsy may also be anticipated for patients with microcalcifications without tissue distortion.

Adult↗
PubMed2001

Concerns for the durability of the proximal abdominal aortic aneurysm endograft fixation from a 2-year and 3-year longitudinal computed tomography angiography study.

OBJECTIVE: To provide a long-term perspective on the durability of the proximal abdominal aortic aneurysm endograft fixation from a single device series with perpendicular neck measurements in two groups of patients with complete 2- and 3-year follow-up. DESIGN: This was a prospective study of postoperative, radiologic images. SETTING: The study used a referral center, institutional practice, and ambulatory patients. SUBJECTS: From January 1994 until May 1998, 37 endografts were implanted for abdominal aortic aneurysm. In the first postoperative year, there were four unrelated deaths and six conversions, leaving 27 patients with complete 24-month data and 13 with complete 36-month data. MAIN OUTCOME MEASURE: Computed tomography angiograms were processed on a work station to measure the neck perpendicular to the central lumen line of the aorta. The surface area at the proximal endovascular anastomosis was recorded at each follow-up interval and related to the postoperative size at the same level. RESULTS: Significant dilatation of the surface area was found: 20% (16% to 27%) at 24 months (c2 = 30; P < .001, Friedman) and 23% (18% to 28%) at 36 months (c2 = 27; P < .001, Friedman). This increase in neck size was continuous and linear, with a yearly rate of approximately 10% surface area; translated into diameter, this approximates 1 mm/y. CONCLUSION: A continuous aortic enlargement of approximately 1 mm/y at the level of the proximal endovascular anastomosis was found. Because of the practice of oversizing the endograft relative to the infrarenal aortic neck, a loss of the endovascular seal may not become apparent until several years after endovascular abdominal aortic aneurysm repair is performed.

Aged↗
PubMed2001

Distal aortic diameter and peripheral arterial occlusive disease.

OBJECTIVE: Several studies have reported an association between abdominal aortic dilatation and peripheral arterial occlusive disease. Narrowing of aortic diameter, also called abdominal aortic hypoplasia, and peripheral arterial occlusive disease have received insufficient attention. Precise estimates of the relationship between aortic hypoplasia and peripheral arterial occlusive disease are lacking. In this study, we assessed the relationship between abdominal aortic diameter and peripheral arterial occlusive disease. METHODS: In this cross-sectional study, we analyzed 1572 patients 18 to 79 years of age, newly referred to the vascular center of our hospital with clinically manifest atherosclerotic arterial disease or for treatment of cardiovascular risk factors. Diameter measurements were used to subdivide patients according to tertiles of abdominal aortic diameter. Peripheral arterial occlusive disease was assessed by adjusted Rose questionnaire, ankle-brachial pressure index, and the presence of gangrene or leg ulcers. RESULTS: Compared with patients with normal aortic diameter, peripheral arterial occlusive disease was twice as prevalent in patients at both ends of the aortic diameter spectrum. When the lowest tertile was compared with the middle tertile in male patients, the adjusted odds ratio was 1.7 (95% CI, 1.0-3.1). When the highest tertile was compared with the middle tertile, the adjusted odds ratio was 2.1 (95% CI, 1.2-3.4). Similar results were found in female patients. The adjusted odds ratio of lowest versus middle tertile was 2.4 (95% CI, 1.1-5.0) and 1.8 (95% CI, 0.8-4.0) when the highest tertile was compared with the middle tertile. CONCLUSION: The risk of peripheral arterial occlusive disease was increased in the lower and upper distribution of aortic diameter. Apparently, both patients with an aortic diameter too large and patients with an aortic diameter too small are prone to peripheral arterial occlusive disease. This is the first large study that shows that small aortic diameter is associated with peripheral arterial occlusive disease.

Adolescent↗
PubMed2001

Clinical features associated with internal carotid artery occlusion do not correlate with MRA cerebropetal flow measurements.

OBJECTIVES: The aetiology of clinical symptoms in patients with severe internal carotid artery (ICA) lesions may be thromboembolic or haemodynamic. The purpose was to assess whether changes in cerebropetal blood flow caused by an ICA occlusion have an effect on clinical symptoms and cerebral metabolism. METHODS: Forty three patients with an ICA occlusion who had hemispheric ischaemia (transient ischaemic attack or stroke), retinal ischaemia, or without symptoms, and 34 patients without significant ICA lesions with either hemispheric ischaemia or no symptoms were studied. Magnetic resonance angiography (MRA) was used to investigate total cerebropetal flow (flow in the ICAs plus basilar artery) and the flow in the middle cerebral arteries. Cerebral metabolic changes in the flow territory of the middle cerebral artery were determined with proton MR spectroscopy. RESULTS: Low total cerebropetal flow (r=-0.15, p<0.05) and low middle cerebral artery flow (r=-0.31, p<0.001) were found in patients with an ICA occlusion, but did not correlate with the clinical syndrome. By contrast, patients with prior symptoms of hemispheric ischaemia had decreased cerebral N-acetylaspartate/choline ratios (r=-0.35, p<0.001). However, the presence of an ICA occlusion (and subsequent low flow) did not correlate with low N-acetylaspartate/choline ratios. CONCLUSION: Neurological deficit caused by (transient) hemispheric ischaemia is associated with low N-acetylaspartate/choline ratios, whereas prior clinical features are not associated with low cerebropetal blood flow, as measured with MR angiography. As a result, differences in cerebropetal flow cannot explain why patients with similar carotid artery disease experience different neurological features.

Aged↗
PubMed2001

Reduction of patient motion artifacts in digital subtraction angiography: evaluation of a fast and fully automatic technique.

The performance of an automatic technique for the reduction of patient motion artifacts in digital subtraction angiography was evaluated. Four observers assessed the quality of 104 cerebral digital subtraction angiographic images that were processed by means of both the automatic technique and manual pixel shifting. The automatic technique resulted in better image quality and was considerably less time-consuming.

Adult↗
PubMed2001

Risk factors for cancellation of stereotactic large core needle biopsy on a prone biopsy table.

Among patients undergoing stereotactic needle biopsy of the breast on a prone biopsy table, a substantial proportion of planned procedures are terminated prematurely. This study was undertaken to identify risk factors for cancellation of these procedures and to derive a clinical rule for predicting cancellation. Risk factors for cancellation were assessed in a group of 476 consecutive patients with non-palpable lesions planned for large core needle biopsy. 64 (13%) of these planned procedures were cancelled. Multivariate regression analysis was applied to identify independent risk factors for cancellation. Validation took place by applying the logistic rule on a validation set, including 5 cancelled and 35 successful biopsy procedures. Mammograms that were difficult to interpret owing to extremely dense breast tissue, axillary location of the non-palpable lesion, body mass index below 20, less than 15 mm distance from the lesion to the chest wall or the presence of more than one non-palpable lesion were identified as independent risk factors. The logistic rule discriminated patients with successful and cancelled biopsy procedures with a receiver operator characteristic (ROC) area of 0.72. In the validation set, the area under the ROC curve was 0.92. The prediction rule, based on mammographic and clinical findings, discriminated patients with successful and cancelled needle biopsy procedures to a certain extent. The risk of cancellation of the stereotacic biopsy procedure is considerable in cases of very dense breast tissue or the presence of multiple risk factors.

Biopsy, Needle↗
PubMed2000

[Endovascular stent implantation as a treatment for iliac artery disease].

A stent is an endovascular prosthesis that may be used in the treatment of intermittent claudication caused by lesions of the A. iliaca communis and the A. iliaca externa in which earlier balloon dilatation has proved insufficiently effective. The expansion is caused by inflation of an angioplasty balloon (plastic remodelling: Palmaz stent) or by self-expansion due to elastic transformation as in the Wail stent or to thermic memory metal, as in the Memotherm stent. Evaluation of the literature shows that stent placement is a safe method of treatment. The proportion of initial technical success appears to be higher than that of balloon angioplasty, especially in the treatment of total occlusions. The haemodynamic situation immediately after treatment also appears to be better in case of stent placement. Long-term comparison of the clinical efficacy is not well possible because the published studies differ with regard to patient population, definition of indication and criteria of success.

Angioplasty, Balloon, Coronary↗
PubMed2000

Repeated quantitative perfusion and contrast permeability measurement in the MRI examination of a CNS tumor.

This study reports on the results of quantitative MRI perfusion and contrast permeability measurement on two occasions in one patient. The measurements were separated 81 days in time. The tumor grew considerably in this period, but no change was found with respect to perfusion and contrast permeability. Non-involved white matter values were reproduced to demonstrate repeatability. The presented approach to dynamic susceptibility contrast MRI allows fast and repeatable quantitative assessment of perfusion and is easily integrated in a conventional brain tumor protocol.

Adult↗
PubMed2000

Dilatation of the proximal neck of infrarenal aortic aneurysms after endovascular AAA repair.

OBJECTIVES: to assess size changes of the proximal aortic neck after endograft placement. METHODS: since 1994, 54 consecutive patients have undergone abdominal aortic aneurysm (AAA) repair with the Endovascular Technologies (EVT) endograft. The study group comprised the 33 patients who had completed at least six months of the prospective follow-up protocol. The pre-, postoperative and follow-up helical computed tomography (CT) angiograms (CTAs) were processed on a workstation. The proximal neck dimensions were measured perpendicular to the central lumen line of the aortic neck. The cross-sectional area was measured at the proximal attachment system and at 1 cm proximal to the renal arteries. RESULTS: while the dimensions of suprarenal aorta did not change, a significant dilatation of the proximal neck was found. The median increase was 10.3% at 6 months and 15.5% at 12 months. No correlation could be found between the amount of dilatation and pre- or postoperative neck-size, graft diameter and amount of graft-oversizing. CONCLUSION: the infrarenal aortic neck demonstrates continued dilatation during follow-up after endograft placement.

Aged↗