The clinical feasibility of deep hyperthermia treatment in the head and neck: new challenges for positioning and temperature measurement.

To apply high-quality hyperthermia treatment to tumours at deep locations in the head and neck (H&N), we have designed and built a site-specific phased-array applicator. Earlier, we demonstrated its features in parameter studies, validated those by phantom measurements and clinically introduced the system. In this paper we will critically review our first clinical experiences and demonstrate the pivotal role of hyperthermia treatment planning (HTP). Three representative patient cases (thyroid, oropharynx and nasal cavity) are selected and discussed. Treatment planning, the treatment, interstitially measured temperatures and their interrelation are analysed from a physics point of view. Treatments lasting 1 h were feasible and well tolerated and no acute treatment-related toxicity has been observed. Maximum temperatures measured are in the range of those obtained during deep hyperthermia treatments in the pelvic region but mean temperatures are still to be improved. Further, we found that simulated power absorption correlated well with measured temperatures illustrating the validity of our treatment approach of using energy profile optimizations to arrive at higher temperatures. This is the first data proving that focussed heating of tumours in the H&N is feasible. Further, HTP proved a valuable tool in treatment optimization. Items to improve are (1) the transfer of HTP settings into the clinic and (2) the registration of the thermal dose, i.e. dosimetry.

Predicting patient-specific expansion of abdominal aortic aneurysms.

OBJECTIVE: Local anatomy and the patient's risk profile independently affect the expansion rate of an abdominal aortic aneurysm. We describe a hybrid method that combines finite element modelling and statistical methods to predict patient-specific aneurysm expansion. METHODS: The 3-D geometry of the aneurysm was imaged with computed tomography. We used finite element methods to calculate wall stress and aneurysm expansion. Expansion rate was adjusted by risk factors obtained from a database of 80 patients. Aneurysm diameters predicted with and without the risk profiles were compared with diameters measured with ultrasound for 11 patients. RESULTS: For this specific group of patients, local anatomy contributed 62% and the risk profile 38% to the aneurysmal expansion rate. Predictions with risk profiles resulted in smaller root mean square errors than predictions without risk profiles (2.9 vs. 4.0 mm, p < 0.01). CONCLUSIONS: This hybrid approach predicted aneurysmal expansion for a period of 30 months with high accuracy.

Clinical endpoints in peripheral endovascular revascularization trials: a case for standardized definitions.

BACKGROUND: Endovascular therapy is a rapidly expanding option for the treatment of patients with peripheral arterial disease (PAD), leading to a myriad of published studies reporting on various revascularization strategies. However, these reports are often difficult to interpret and compare because they do not utilize uniform clinical endpoint definitions. Moreover, few of these studies describe clinical outcomes from a patients' perspective. METHODS AND RESULTS: The DEFINE Group is a collaborative effort of an ad-hoc multidisciplinary team from various specialties involved in peripheral arterial disease therapy in Europe and the United States. DEFINE's goal was to arrive at a broad based consensus for baseline and endpoint definitions in peripheral endovascular revascularization trials for chronic lower limb ischemia. In this project, which started in 2006, the individual team members reviewed the existing pertinent literature. Following this, a series of telephone conferences and face-to-face meetings were held to agree upon definitions. Input was also obtained from regulatory (United States Food and Drug Administration) and industry (device manufacturers with an interest in peripheral endovascular revascularization) stakeholders, respectively. The efforts resulted in the current document containing proposed baseline and endpoint definitions in chronic lower limb PAD. Although the consensus has inevitably included certain arbitrary choices and compromises, adherence to these proposed standard definitions would provide consistency across future trials, thereby facilitating evaluation of clinical effectiveness and safety of various endovascular revascularization techniques. CONCLUSION: This current document is based on a broad based consensus involving relevant stakeholders from the medical community, industry and regulatory bodies. It is proposed that the consensus document may have value for study design of future clinical trials in chronic lower limb ischemia as well as for regulatory purposes.

[Dutch study on the optimal treatment strategy for patients with a first or second occurrence of gastro-oesophageal variceal bleeding: the TIPS-TRUE trial]. / Nederlandse studie naar de beste behandelstrategie bij patiënten met een eerste of tweede oesofagus- of maagvaricesbloeding: de TIPS-TRUE-trial.

The main options for secondary prevention of gastrooesophageal variceal bleeding are endoscopic therapy and treatment with propranolol. Creation ofa transjugular intrahepatic portosystemic shunt (TIPS) is currently considered a valuable secondary 'rescue' treatment when other therapies fail. Recent data suggest that the use of covered stents markedly increases the efficacy of TIPS, compared with conventional uncovered stents. Therefore, a multicentre randomised trial was designed to compare the effects of TIPS using covered stents with those of endoscopic therapy plus propranolol in patients with a first or second episode ofgastro-oesophageal variceal bleeding. TIPS will be performed in 4 university centres with relevant expertise. The trial will hopefully gain nationwide support, and all centres in The Netherlands are cordially invited to participate.

Post-processing of dynamic gadolinium-enhanced magnetic resonance imaging exams of the liver: explanation and potential clinical applications for color-coded qualitative and quantitative analysis.

The purpose of this article is to explain and illustrate the current status and potential applications of automated and color-coded post-processing techniques for the analysis of dynamic multiphasic gadolinium-enhanced magnetic resonance imaging (MRI) of the liver. Post-processing of these images on dedicated workstations allows the generation of time-intensity curves (TIC) as well as color-coded images, which provides useful information on (neo)-angiogenesis within a liver lesion, if necessary combined with information on enhancement patterns of the surrounding liver parenchyma. Analysis of TIC and color-coded images, which are based on pharmacokinetic modeling, provides an easy-to-interpret schematic presentation of tumor behavior, providing additional characteristics for adequate differential diagnosis. Inclusion of TIC and color-coded images as part of the routine abdominal MRI workup protocol may help to further improve the specificity of MRI findings, but needs to be validated in clinical decision-making situations. In addition, these tools may facilitate the diagnostic workup of disease for detection, characterization, staging, and monitoring of antitumor therapy, and hold incremental value to the widely used tumor response criteria.

Drug-eluting stents in renal artery stenosis.

Because of higher acute and long-term success rates compared with balloon angioplasty alone, percutaneous stent implantation has become an accepted therapy for the treatment of atherosclerotic renal artery stenosis. Restenosis rates after successful renal stent placement vary from 6 up to 40%, depending on the definition of restenosis, the diameter of the treated vessel segment and comorbidities. The safety and efficacy of drug-eluting stents for the treatment of renal-artery stenosis is poorly defined. The recently published GREAT study is the only prospective study, comparing bare-metal and sirolimus-coated low profile stent systems in renal artery stenosis, showing a relative risk reduction of angiographic binary in-stent restenosis by 50%. This is an opinion paper on indications, current treatment options and restenosis rates following renal artery stenting and the potential use of drug-eluting stents for this indication.

Shrinkage of abdominal aortic aneurysm after successful endovascular repair: results from single center study.

AIM: In the literature, the behavior of the aneurysm sac after endovascular grafting has been the subject of significant speculation. It has been suggested that shrinkage of the abdominal aortic aneurysm (AAA) is different for various endografts. This study was undertaken to evaluate endograft-specific differences in aneurysm sac shrinkage and to evaluate other factors that may influence AAA shrinkage. METHODS: Forty patients with an AAA treated with endovascular grafts with a complete 18 months follow-up and complete CT angiography (CTA) follow-up were available for analysis. All patients with a persistent endoleak, endograft migration or any other reason for intervention or conversion were excluded from this analysis. Shrinkage was defined as a reduction in the AAA diameter of 5 mm or more. Chi-squared tests were used to test whether shrinkage was different for the kind of stent graft used (Gore Excluder vs Cook-Zenith), preexistent AAA diameter (<65 mm vs =or>65 mm), and AAA status (ruptured vs non-ruptured) (two-sided; a= 0.05). RESULTS: At 18 months after treatment, shrinkage was observed in 14 patients (52%) of the 27 patients treated with a Gore Excluder endograft and in 8 patients (62%) of the 13 patients treated with a Cook Zenith endograft (P=0.74). In 31 patients with a diameter <65 mm, shrinkage was observed in 19 patients (61%) whereas of the 9 patients with a diameter =or>65 mm, shrinkage was observed in 3 patients (33%) (P=0.253). Of the 34 patients with a non-ruptured AAA, shrinkage was observed in 18 patients (53%) versus of the 6 patients with a ruptured AAA shrinkage was observed in 4 patients (66%) (P=0.673). CONCLUSIONS: From this study can be concluded that the influence of the endograft on shrinkage of the AAA sac might be less prominent than suggested in the literature. Furthermore, our study shows that other factors such as preexistent AAA diameter may influence AAA shrinkage after endovascular repair.

Lung tumor tracking during stereotactic radiotherapy treatment with the CyberKnife: Marker placement and early results.

Lung tumor tracking during stereotactic radiotherapy with the CyberKnife requires the insertion of markers in or close to the tumor. To reduce the risk of pneumothorax, three methods of marker placement were used: 1) intravascular coil placement, 2) percutaneous intrathoracal, and 3) percutaneous extrathoracal placement. We investigated the toxicity of marker placement and the tumor response of the lung tumor tracking treatment. Markers were placed in 20 patients with 22 tumors: 13 patients received a curative treatment, seven a palliative. The median Charlson Comorbidity Score was 4 (range: 1-8). Platinum fiducials and intravascular embolisation coils were used as markers. In total, 78 markers were placed: 34 intrathoracal, 23 intravascular and 21 extrathoracal. The PTV equaled the GTV + 5 mm. A median dose of 45 Gy (range: 30-60 Gy, in 3 fractions) was prescribed to the 70-85% isodose. The response was evaluated with a CTscan performed 6-8 weeks after the last treatment and routinely thereafter. The median follow-up was 4 months (range: 2-11). No severe toxicity due to the marker placement was seen. Pneumothorax was not seen. The local control was 100%. Four tumors in four patients showed a complete response, 15 tumors in 14 patients a partial response, and three tumors in two patients with metastatic disease had stable disease. No severe toxicity of marker placement was seen due to the appropriate choice of one of the three methods. CyberKnife tumor tracking with markers is feasible and resulted in excellent tumor response. Longer follow-up is needed to validate the local control.

[Right-ventricular dysfunction and the pulmonary vascular obstruction index: predictable variables of the clinical course over 3 months in patients with acute lung emboli]. / Rechterventrikeldisfunctie en index voor pulmonale vasculaire obstructie: voorspellende variabelen voor het klinische beloop gedurende 3 maanden bij patiënten met acute longembolie.

OBJECTIVE: To quantify right-ventricular dysfunction and the pulmonary artery obstruction index, in patients with acute pulmonary embolism, using helical CT, and to assess the prognostic value of these parameters. DESIGN: Prospective. METHOD: In 120 consecutive patients with proven acute pulmonary embolism, the extent of right-ventricular dysfunction was assessed by quantifying the ratios of the right to left-ventricular short-axis diameters (RV/LV ratio) and the extent ofobstruction ofthe pulmonary-artery circulation by using helical CT images. Regression analysis was used to correlate these parameters with patient outcome. RESULTS: Right-ventricular dysfunction (RV/LV ratio > 1.0) was seen in 69 patients (57.5%). Seven patients died as a direct result of pulmonary embolism. Both the RV/LV ratio and the obstruction index were significant risk factors for mortality within three months (p = 0.04 and 0.01 respectively). The positive predictive value for pulmonary embolism-related mortality of an RV/LV ratio > 1.0 was 10.1% (95% CI: 2.9-17.4). The negative predictive value for an uneventful outcome of an RV/LV ratio < or = 1.0 was 100% (95% CI: 94.3-100). There was a 11.2-fold risk of dying of pulmonary embolism in patients with an obstruction index > or = 40% (95% CI: 1.3-93.6). CONCLUSION: Markers of right-ventricular dysfunction and pulmonary vascular obstruction, assessed by helical CT-examination at baseline, help to predict mortality during follow-up of patients with acute pulmonary embolism.

[Complications within 30 days following placement of a carotid stent with cerebral protection in patients with considerable symptomatic carotid stenosis; Erasmus MC, Rotterdam, 1999-2004]. / Complicaties in de eerste 30 dagen na plaatsing van een carotisstent met cerebrale bescherming bij pati nten met een aanzienlijke, symptomatische carotisstenose; Erasmus MC, Rotterdam, 1999-2004.

OBJECTIVE: To describe the complications that occur within 30 days following the placement of a stent in the carotid artery in patients with considerable symptomatic carotid stenosis. DESIGN: Retrospective. METHOD: Data were collected on 98 patients who received a carotid stent due to symptomatic carotid stenosis of > or = 70% of the lumen at the Erasmus MC, Rotterdam, the Netherlands, in the years 1999-2004. A filter, distal occlusion balloon or the Parodi anti-embolism system was used to prevent cerebral embolism. Outcome measures were complications within 30 days following intervention. RESULTS: Four patients were excluded in the period between diagnosis and stenting. Major complications occurred in 3 patients: 1 died due to cerebral haemorrhage and 2 experienced cerebral infarction. Transient neurological complications occurred in 4 patients who recovered completely. Dissection of the renal artery occurred in 1 patient, which necessitated a stent. Vascular damage of the internal carotid artery was not observed in any patient. The 3 major adverse events and 3 of the 4 minor adverse events occurred in the first 47 patients treated. None of the last 47 patients treated developed major adverse events.

Helical computed tomography and alternative diagnosis in patients with excluded pulmonary embolism.

OBJECTIVE: A clinical diagnosis of pulmonary embolism (PE) is confirmed objectively in 20-30% of patients. Helical computed tomography (CT) can allow an alternative diagnosis to be made. The frequency and validity of alternative diagnoses on helical CT in consecutive patients presenting with clinically suspected PE was assessed. PATIENTS AND METHODS: In all 512 prospectively analyzed patients helical CT scan was performed, and apart from presence or absence of PE, pathologic changes in lung parenchyma, mediastinum, cardiovascular system, pleura and skeleton were recorded. When possible an alternative diagnosis was given and compared with the final diagnosis after 3 months follow-up. RESULTS: In 130 patients (25.4%) PE was excluded and an alternative diagnosis considered likely. In 123 of the 130 patients (94.6%) this diagnosis was unchanged at 3 months follow-up. The diagnoses included pneumonia (n = 67), malignancy (n = 22), pleural fluid (n = 10), cardiac failure (n = 10), COPD (n = 6) and a variety of other causes (n = 15). The diagnosis changed at follow-up in seven patients (5.4%). An initial diagnosis of pneumonia changed to malignancy in two patients and to pleuritis and cardiac failure in one patient each. In two other patients malignancy and chronic obstructive pulmonary disease (COPD) were ruled out and the diagnosis changed to pneumonia. In one patient the final diagnosis remained unknown after an initial suspicion of malignancy. CONCLUSION: In clinically suspected PE helical CT allows a reliable alternative diagnosis to be made in 25.4% of patients. This feature is an unique advantage in comparison with other diagnostic tests and supports the decision of taking helical CT as first line test in suspected PE.

A critical appraisal of non-invasive diagnosis and exclusion of deep vein thrombosis and pulmonary embolism in outpatients with suspected deep vein thrombosis or pulmonary embolism: how many tests do we need?

The requirement for a safe diagnostic strategy should be based on an overall posttest incidence of venous thromboembolism of less than 1% during 3 month follow-up. Compression ultrasonography (CUS) has a negative predictive value (NPV) of 97% to 98% indicating the need of repeated CUS testing. Serial CUS testing is safe but you have to repeat 100 CUS to find 1 or 2 CUS positive for deep vein thrombosis (DVT), which is not cost-effective indicating the need to improve the diagnostic work-up of DVT by the use of clinical score assessment and D-dimer testing. The combination of a less sensitive D-dimer test (SimpliRed) and low clinical score does not, whereas the combination of a sensitive D-dimer test (ELISA VIDAS or Tinaquant) and low clinical score does safely exclude DVT without the need of CUS. The combination of a first negative CUS and a negative less sensitive D-dimer test (SimpliRed) or a sensitive ELISA D-dimer at a higher cut off level of 1,000 ng/ml safely excludes DVT with a NPV of > 99% without the need to repeated CUS in about 60%. The sequential use of a sensitive D-dimer and clinical score assessment will safely reduce the need for CUS testing by 40% to 60%. Large prospective outcome studies demonstrate that one negative examination with complete duplex color ultrasonography (CCUS) of the proximal and distal veins of the affected leg with suspected DVT is safe to withhold anticoagulant treatment with a NPV of 99.5%. This indicates that CCUS is equal or superior to serial CUS or the combined use of clinical score, D-dimer testing and CUS. Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but not for subsegmental PE. A normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test safely exclude PE. Helical spiral CT detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic ventilation perfusion scan (VP-scan) or a high probability VP-scan. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in 5 retrospective studies and in 3 prospective management studies indicate that the NPV of a normal helical spiral CT, a negative CUS of the legs together with a low or intermediate pretest clinical probability is 99%. Helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer followed by CUS will reduce the need for helical spiral CT by 40% to 50%.

[The diagnosis of pulmonary embolism: the best strategies according to the results of a large Dutch multicentre study]. / Diagnostiek bij longembolie; de beste strategieën volgens de resultaten van een grote Nederlandse multicenterstudie.

The Dutch national guidelines for the diagnosis of patients with clinically suspected pulmonary embolism (from 1992 en 1998) are poorly followed in clinical practice, due especially to practical objections. A large multicentre trial to investigate the diagnostic accuracy of the available modalities and of recently developed techniques such as D-dimer determination, (99m)Tc-gas-scintigraphy and spiral CT scanning was started in I997. In the first phase, the diagnostic value was assessed of: spiral CT (sensitivity 69%, specificity 84%; sensitivity for segmental and larger pulmonary embolisms (PE) 86% and for subsegmental PE 21%), (99m)Tc-gas-ventilation scintigraphy (no improvement compared to conventional ventilation scintigraphy), D-dimer determination (sensitivity for segmental PE 93% and for subsegmental PE 53%, specificity 63%), clinical decision rules (in combination with D-dimer determination; sensitivity 100%, specificity 11%) and echography of the deep venous system (sensitivity 26% for segmental PE and 7% for subsegmental PE, specificity 97%). In the second phase, the feasibility of two new potentially cost-effective diagnostic algorithms was evaluated on the basis of the results obtained in the first phase and data in the literature. In 631 patients, a clinical risk estimate was made and D-dimer determination was done, followed by a ventilation-perfusion scan and serial compression echography of the leg veins. An apparent recurrence of PE occurred in 6 of 466 patients in whom no PE had been found originally (1.3%; 95% CI: 0.5-2.8). The average costs were 812 Euro,--per patient. In 510 patients, a spiral CT followed by compression echography was performed. Recurrent PE occurred in 3 of 378 patients with initial normal tests (0.8%; 95% CI: 0.2-2.3). The average costs were 883 Euro,--per patient. A combination of both strategies can be cost-effective with a cost 674 Euro,--per patient (recurrence rate: 1.9%). Both the strategy starting with a clinical-risk estimate and a D-dimer determination as well as the strategy consisting of spiral CT and serial echography were safe and cost-effective. According to the results of a survey of hospital directors, internists and pulmonologists, both are well accepted in clinical practice.

Non-invasive diagnosis of pulmonary embolism, anno 2005.

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of >99% : a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value is 85 to 88% for a high probability ventilation-perfusion lung scan (VP-scan) and >95% for helical spiral CT. The prevalence of PE in management studies of symptomatic patients with a non-diagnostic VP-scan is 20 to 24%. Helical spiral CT detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic VP-scan or a high probability VP-scan. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in three retrospective studies and in two prospective management study indicate that the negative predictive value of a normal helical spiral CT, a negative compression ultrasonography of the legs (CUS) together with a low or intermediate pre-test clinical probability is >99%. Therefore, helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer followed by CUS will reduce the need for helical spiral CT by 40 to 50%.

Accuracy of single-detector spiral CT in the diagnosis of pulmonary embolism: a prospective multicenter cohort study of consecutive patients with abnormal perfusion scintigraphy.

BACKGROUND: Spiral computed tomography (CT) has emerged as a potentially conclusive diagnostic test to exclude pulmonary embolism (PE) in patients with non-high probability scintigraphy and is already widely used-sometimes as the sole primary diagnostic test in the diagnosis of suspected PE. Its true sensitivity and specificity has, however, not been evaluated previously in a large cohort of consecutive patients. METHODS: In a multicenter prospective study 627 consecutive patients with clinically suspected PE were studied. Patients with normal perfusion scintigraphy were excluded from further analysis. Single-detector spiral CT scanning and ventilation scintigraphy were then performed in all patients to diagnose PE, while pulmonary angiography was performed as the gold standard. The only exceptions were those patients who had both a high-probability VQ scan and a CT scan positive for PE: these patients were considered to have PE and did not undergo additional pulmonary angiography. All imaging tests were read by independent expert panels. RESULTS: Five hundred and seventeen patients were available for complete analysis. The prevalence of PE was 32%. Spiral CT correctly identified 88 of 128 patients with PE, and 92 of 109 patients without PE, for a sensitivity and specificity of 69%[95% confidence interval (CI) 63-75] and 84% (95% CI 80-89), respectively. The sensitivity of spiral CT was 86% (95% CI 80-92) for segmental or larger PE and 21% (95% CI 14-29) in the group of patients with subsegmental PE. CONCLUSION: The overall sensitivity of spiral CT for PE is too low to endorse its use as the sole test to exclude PE. This holds true even if one limits the discussion to patients with larger PE in segmental or larger pulmonary artery branches. We conclude that, in patients with clinically suspected PE and an abnormal perfusion scintigraphy, single-slice detector spiral CT is not sensitive enough to be used as the sole test to exclude PE.

Interstitial laser coagulation with temporary hepatic artery occlusion for patients with cirrhosis and irresectable hepatoma.

BACKGROUND: The aim was to determine the degree of local control of hepatocellular carcinoma (HCC) in patients with cirrhotic liver disease when treated with ultrasonographically guided interstitial laser coagulation (ILC) with temporary hepatic artery occlusion. METHODS: Sixteen patients with 24 HCC tumours were treated. Follow-up was by computed tomography or magnetic resonance imaging every 3 months. RESULTS: Nineteen of 24 tumours showed complete necrosis immediately after treatment, and there was no tumour recurrence during follow-up (mean 14 months, median 12 months). No effect on liver function was observed after 1 week and there was no death. In 13 of the 16 patients, new HCC foci developed at other sites. CONCLUSION: Percutaneous ILC combined with temporary hepatic artery occlusion during a single session is an effective local treatment for HCC nodules smaller than 5 cm. However, new HCC lesions develop in the majority of patients, which underscores the need for adjuvant therapy or repeated treatment in these patients.

Non-invasive exclusion and diagnosis of pulmonary embolism by sequential use of the rapid ELISA D-dimer assay, clinical score and spiral CT.

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for its subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of > 99%: a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value of a high probability ventilation-perfusion lung scan (VP-scan) is only 85% to 87%. The combination of a low clinical score and a non-diagnostic VP-scan safely exclude PE without the need of angiography. The prevalence of PE and that of an alternative diagnosis in symptomatic patients with a non-diagnostic VP-scan are 10% to 20% and 30% to 45%, respectively. Helical spiral computed tomography (CT) detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic or high probability VP-scan. The positive predictive value of the spiral CT is > 95%. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in retrospective outcome studies and in prospective multicenter management studies indicate that the negative predictive value of a negative spiral CT preceded or followed by a negative compression ultrasonography (CUS) is > 99%. Therefore, a helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. A negative rapid ELISA VIDAS D-dimer test result will reduce the need for helical spiral CT by 25% to 35%.

Imaging of coronary atherosclerosis and identification of the vulnerable plaque.

Identification of the vulnerable plaque responsible for the occurrence of acute coronary syndromes and acute coronary death is a prerequisite for the stabilisation of this vulnerable plaque. Comprehensive coronary atherosclerosis imaging in clinical practice should involve visualisation of the entire coronary artery tree and characterisation of the plaque, including the three-dimensional morphology of the plaque, encroachment of the plaque on the vessel lumen, the major tissue components of the plaque, remodelling of the vessel and presence of inflammation. Obviously, no single diagnostic modality is available that provides such comprehensive imaging and unfortunately no diagnostic tool is available that unequivocally identifies the vulnerable plaque. The objective of this article is to discuss experience with currently available diagnostic modalities for coronary atherosclerosis imaging. In addition, a number of evolving techniques will be briefly discussed.

The benefit of STent placement and blood pressure and lipid-lowering for the prevention of progression of renal dysfunction caused by Atherosclerotic ostial stenosis of the Renal artery. The STAR-study: rationale and study design.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipid-lowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients. METHOD: Patients with an ARAS of > or = 50% and renal failure (creatinine (Cr) clearance < 80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance > 20% compared to baseline. This trial will include 140 patients.

Shrinkage of the distal renal artery 1 year after stent placement as evidenced with serial intravascular ultrasound.

The objective of this study was to determine the quantitative intravascular ultrasound (IVUS) and angiographic changes that occur during 1 year follow-up after renal artery stent placement, given that restenosis continues to be a limitation of renal artery stent placement. 38 consecutive patients with symptomatic renal artery stenosis treated with Palmaz stent placement were studied prospectively. IVUS and angiography were performed at the time of stent placement and at 1 year follow-up. At follow-up, angiographic restenosis was seen in 14% of patients. The lumen area in the stent, seen with IVUS, was significantly decreased from 24+/-5.6 mm(2) to 17+/-5.6 mm(2) (p<0.001) solely due to plaque accumulation. The distal main renal artery showed a significant decrease in lumen area owing to a significant vessel area decrease from 39+/-14.0 mm(2) to 29+/-9.3 mm(2) (p<0.001) without plaque accumulation. Angiographic analysis confirmed this reduction in luminal diameter and showed that the distal renal artery diameter at follow-up was significantly smaller than before stent placement (86+/-23.0% vs 104+/-23.9% of the contralateral renal artery diameter; p=0.003). Besides plaque accumulation in the stent, unexplained shrinkage of the distal main renal artery was evidenced with IVUS and angiography 1 year following stent placement.