Summary Background: Approximately one of four patients with acute proximal deep vein thrombosis (DVT) given anticoagulation and compression therapy develops postthrombotic syndrome (PTS). Accelerated removal of thrombus by thrombolytic agents may increase patency and prevent PTS. Objectives: To assess short-term efficacy of additional catheter-directed thrombolysis (CDT) compared to standard treatment alone. Patients and methods: Open, multicenter, randomized, controlled trial. Patients (18 to 75 years) with iliofemoral DVT and symptoms <21 days were randomized to receive additional CDT or standard treatment alone. Iliofemoral patency after six months was investigated using duplex ultrasound and air-plethysmography assessed by investigator blinded to previous treatment. Results: 103 patients (64 men, mean age 52 years) were allocated additional CDT (n=50) or standard treatment alone (n=53). Following CDT grade III (complete) lysis was achieved in 24 and grade II (50-90%) lysis in 20. One patient suffered major bleeding and three had clinically relevant bleeding related to the CDT procedure. Iliofemoral patency after six months was found in 32 (64.0%) in CDT group vs. 19 (35.8%) controls, corresponding to an absolute risk reduction (RR) of 28.2%(95% CI: 9.7-46.7%; P=0.004). Venous obstruction was found in 10 (20.0%) in CDT group vs. 26 (49.1%) controls; absolute RR 29.1%(95% CI: 20.0-38.0%; P=0.004). Femoral venous insufficiency did not differ between the two groups. Conclusions: Additional CDT increased iliofemoral patency after six months from 36% to 64%. The ongoing long-term follow-up of this study will document whether patency is related to improved functional outcome.

BACKGROUND: The conventional treatment of acute deep vein thrombosis (DVT) is anticoagulation and compression therapy, as recommended in the international guidelines. Anticoagulation prevents recurrent venous thrombosis, pulmonary embolism, and death. Compression therapy reduces the risk of developing long-term sequelae, that is, postthrombotic syndrome (PTS). Evaluation of systemic thrombolysis has shown effective thrombolysis and a likely reduction in PTS but at the cost of increased risk of bleeding complications. Catheter-directed thrombolysis (CDT) was introduced for rapid removal of thrombi and salvage of venous valves with less systemic thrombolytic effect, and is being offered to selected patients with iliofemoral DVT to prevent development of PTS. Case series have shown technical and thrombolytic success; however, no randomized studies have evaluated the long-term clinical effects of venous CDT. The aim of the CaVenT study is to investigate the role of adjunctive CDT by evaluating its clinical efficacy and safety compared with conventional treatment alone in patients with acute iliofemoral DVT. METHODS: The CaVenT study is an open, randomized, controlled, clinical trial. We plan to include 200 patients who will receive either CDT, in addition to conventional treatment, or conventional treatment alone. The primary outcome measures are patency at 6 months and prevalence of PTS at 2 years. CONCLUSION: Implementation of the CaVenT study will be a contribution toward evidence-based medicine in the treatment of acute proximal DVT of the leg. Any documentation of improved functional outcome will have a significant impact on clinical practice for this patient group and may lead to a modification of existing international guidelines.

Purpose: To assess the interobserver variability of radiologists with varied levels of experience in the interpretation of multidetector computed tomography (MDCT) pulmonary angiographies. Material and Methods: Review of CT pulmonary angiographies performed on patients included in a diagnostic study evaluating a decision-based algorithm for diagnosing pulmonary embolism (PE). Five radiologists, three board-certified general radiologists and two radiology trainees with 2 years' experience, participated in the study. Results: According to the consensus reading, PE was present in 91 (31%) and absent in 194 (67%) patients, while in five patients (1.7%) the interpretations were regarded as equivocal. The per-patient agreement on the diagnosis of PE achieved by each of the four readers compared to the consensus reading was very good (kappa range 0.85-0.92), but peripheral emboli were missed in four to six patients by three of four observers. The agreement on the most proximal level of PE (per-proximal level) assessed by mean kappa value was 0.83 (kappa range 0.68-0.91) for the detection of proximal emboli, 0.61 for segmental emboli (kappa range 0.40-0.80), and 0.38 for emboli in the subsegmental vessels (kappa range 0.0-0.89). Conclusion: The overall agreement on the diagnosis of PE by MDCT for general radiologists and radiology trainees is very good, and we therefore believe that the initial management of patients with suspected PE could be based on the preliminary assessment performed by on-call radiologists with 2 years of experience.

Background. The aim of the study was to investigate the association between the proximal level of the clot and the severity of pulmonary embolism (PE). Methods. The cohort consisted of 99 consecutive patients with PE diagnosed by multi-detector computed tomography. A new score was constructed by calculating the mean value of the largest affected vessel [sub-segmental = 1, segmental = 2, lobar = 3, main pulmonary artery (MPA)= 4] in each lung. Results. A significant association was found between the most proximal level of PE and pulmonary artery obstruction index (PAOI)(P < 0.0001), right ventricular (RV)/left ventricular (LV) ratio (P < 0.0001), and PaO(2)(P = 0.004). No significant association was found between systolic blood pressure and the level of PE. Troponin-T was elevated in none of the sub-segmental, 5% of segmental, 20% of lobar, and in 56% of PEs in the MPA (P = 0.001). Significant association was found between the proposed score and PAOI (P < 0.0001), RV/LV ratio (P < 0.0001), PaO(2)(P < 0.008). Troponin-T was elevated in 10% of level 1, 0% of level 2, 43% level of 3, 66% of level 4 PE (P < 0.0001). Cut-off level score 4 yielded a sensitivity of 84% and a specificity of 74% for the detection of elevated troponin-T. Conclusions. In conclusion, the study indicates that both the most proximal level of PE and the proposed score are related to the severity of PE as determined by blood oxygenation, biochemical and radiological parameters and could therefore be of value for rapid risk stratification of PE. However, the prognostic value of these classifications and their clinical significance needs to be evaluated in properly designed studies.

OBJECTIVES: Our aim was to study the association between the level of D-dimer and the severity of pulmonary embolism (PE) as determined by various biochemical and radiological prognostic markers in order to investigate the potential value of D-dimer as a prognostic marker for the severity of PE. PATIENTS AND METHODS: PE was diagnosed in 100 consecutive out-patients by multi-detector computerized tomography. One patient was excluded and the final cohort consisted of 99 patients. Pulmonary Artery Obstruction Index (PAOI) and Right Ventricular/Left Ventricular (RV/LV) ratio were assessed. RESULTS: The median value for D-dimer was 5.0 mg/L (inter-quartile range: 1.8, 12.2). There was a significant association between log D-dimer, and between log RV/LV (r=0.45), log PAOI (r=0.5), and PaO(2)(r=0.40). The multivariate analysis showed an increased association between log D-dimer and between log RV/LV ratio (r=0.54) and log PAOI (r=0.52) after adjusting for age, gender and for the duration of symptoms. Significant association was found between the level of D-dimer and the most proximal level of PE (p<0.0005). There was a significant dose-response relationship between the level D-dimer and between Troponin-T and the frequency of thrombolysis (p<0.0005). In the subgroup of patients with D-Dimer over the upper quartile (>12.2), 12 (67%) patients had elevated Troponin-T and 8 (32%) patients received thrombolysis, compared to 1 (5%) patient with elevated Troponin-T and none treated with thrombolysis in the subgroup of patients with D-dimer<lower quartile. CONCLUSIONS: We have shown that the level of D-dimer is related to the severity of PE assessed by various radiological, biochemical and clinical markers and might have a potential value as prognostic marker for the severity of PE.

OBJECTIVES: A prospective outcome study designed to evaluate a simple strategy for the management of outpatients with suspected pulmonary embolism (PE), based on clinical probability, D-dimer, and multi-slice computed tomography (MSCT). METHODS: A cohort of 432 consecutive patients admitted to the emergency department with suspected PE was managed by sequential non-invasive testing. Patients in whom PE was ruled out were not given anticoagulants, but were followed-up for 3 months. RESULTS: Normal D-dimer and low-intermediate clinical probability ruled out PE in 103 patients [24%(95% CI 20-28)]. Seventeen patients had normal D-dimer, but high clinical probability and proceeded to MSCT. All patients proved negative for PE. A total of 329 (76%) patients underwent MSCT examination. Pulmonary embolism was diagnosed in 93 patients [21.5%(95% CI 18-26)] and was ruled out by negative MSCT in 221 patients [51%(95% CI 46-56)]. MSCT scans were determined as inconclusive in 15 (4.5%) patients. No patient developed objectively verified venous thromboembolism (VTE) during the 3-month follow-up period. However, the cause of death was adjudicated as possibly related to PE in two patients, resulting in an overall 3-month VTE risk of 0.6%(95% CI 0-2.2%). The diagnostic algorithm yielded a definite diagnosis in 96.5% of the patients. CONCLUSIONS: This simple and non-invasive strategy combining clinical probability, D-dimer, and MSCT for the management of outpatients with suspected PE appears to be safe and effective.

BACKGROUND: In recent years, interventional radiology has gained in importance in patient treatment. In order to assess the impact of this trend, the executive committee of the Norwegian Society for Interventional Radiology made a registration of all interventional procedures in Norwegian hospitals in the year 2000. MATERIAL AND METHODS: Data were collected by a questionnaire sent to all Norwegian hospitals. Coronary interventions were not included. RESULTS: Forty-four out of 58 departments returned the questionnaire; 33 stated that they performed interventional procedures. A total of 18 135 procedures were performed in Norway in 2000; we present data on the distribution of types of procedures on different categories of hospitals. INTERPRETATION: A large number of interventional radiological procedures were performed in Norwegian hospitals in the year 2000, types of intervention that are considered very important in patient management in small hospitals, too.