Idiopathic and hereditary haemorrhagic telangiectasia associated pulmonary arteriovenous malformations: comparison of clinical and radiographic characteristics.

AIM: To determine whether there are differences between idiopathic and hereditary haemorrhagic telangiectasia (HHT) associated pulmonary arteriovenous malformations (PAVMs) (HHT-PAVM) regarding clinical and radiographic characteristics, and the results of embolotherapy. MATERIALS AND METHODS: A retrospective analysis was undertaken of all adult and adolescent patients who were diagnosed with a PAVM on chest computed tomography (CT) from January 2006 until August 2019. RESULTS: In total, 41 patients with idiopathic PAVMs and 194 patients with genetically confirmed HHT and PAVMs were included. Idiopathic PAVMs were more frequently observed in female patients, were more solitary, and predominantly located in the lower lobes. The diameter of the feeding artery and type of PAVM (simple versus complex) were similar. Embolotherapy results were comparable between both groups with similar re-embolisation rates. CONCLUSIONS: PAVMs of idiopathic origin are predominantly found in women, more frequently located in the lower lobes, and solitary compared to HHT-PAVMs; however, the outcome of treatment is the same, suggesting that treatment and follow-up should be similar in both groups.

Safety of percutaneous renal cryoablation: an international multicentre experience from the EuRECA retrospective percutaneous database.

OBJECTIVE: To investigate the safety profile of percutaneous cryoablation of renal tumours < 7 cm, utilising data extracted from an international multicentre registry. MATERIALS AND METHODS: A retrospective review of all immediate and delayed complications from a multicentre database was performed and was categorised according to the Clavien-Dindo classification. Statistical analysis was performed for both overall complications (all Clavien-Dindo) and major complications (Clavien-Dindo 3 to 5). The following criteria were identified as potential predictive factors for complications: centre number, modality of image guidance, tumour size (≤ 4 cm vs. > 4 cm), number of tumours treated in the same session (1 vs. > 1) and tumour histology. RESULTS: A total of 713 renal tumours underwent ablation in 647 individual sessions. In 596 of the cases, one tumour was treated; in the remaining 51 cases, several tumours were treated per session. Mean lesion size was 2.8 cm. Fifty-four complications (Clavien-Dindo 1 to 5) occurred as a result of the 647 procedures, corresponding to an overall complication rate of 8.3%. The most frequent complication was bleeding (3.2%), with 9 cases (1.4%) requiring subsequent treatment. The rate of major complication was 3.4%. The only statistically significant prognostic factor for a major complication was a tumour size > 4 cm. CONCLUSION: Percutaneous renal cryoablation is associated with a low rate of complications. Tumours measuring more than 4 cm are associated with a higher risk of major complications. KEY POINTS: • Percutaneous kidney cryoablation has a low rate of complications. • Bleeding is the most frequent complication. • A tumour size superior to 4 cm is a predictive factor of major complication.

Experience with new techniques for the treatment of type II endoleaks post-EVAR.

Endovascular aneurysm management (EVAR) is hampered by persistent arterial blood flow in the aneurysm sac after treatment, known as endoleak (EL). Type II EL consist of blood flow from one or more aortic branch vessels; they only require treatment when the aneurysm sac fails to shrink. Post-EVAR follow up is mostly done with contrast enhanced computed tomography. If a type II EL requiring treatment is found, a variety of options exist, depending on the source of EL and the anatomy. Inferior mesenteric artery EL is best treated by endovascular embolization through the superior mesenteric artery and Riolans' arc. In hypogastric to lumbar artery EL success of endovascular treatment is limited. In these cases a successful embolization of the EL can often be performed by a direct percutaneous approach to the EL inside the aneurysmal sac. CT guidance provides a good way to exactly puncture the EL percutaneously in most cases, but limited workspace and lack of fluoroscopy availability for the ensuing catheter manipulation hampers this technique. A novel way to puncture the EL and subsequently treat it is performed on flat panel detector angiography units. By a rotation around the patients these units provide the possibility to create a cone-beam CT (CBCT) in the angio suite. Using the 3-dimensional dataset thus acquired, a needle path can be planned and the EL nidus can be punctured with great confidence and without danger of inadvertently perforating vital structures. After the EL has been punctured, microcatheters can be inserted to embolize the origins of branch vessels and/or the aneurysm sac can be filled with thrombogenic agents or glue. CBCT guided procedures incur lower radiation dose and have higher accuracy compared to conventional CT guided procedures. Details of CBCT guided procedures; the materials and technique used are detailed in this manuscript.

Direct haemodynamic effects of pulmonary arteriovenous malformation embolisation.

BACKGROUND: Transcatheter embolisation is widely used to close pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Data on the direct cardiovascular haemodynamic changes induced by this treatment are scarce. OBJECTIVES: We investigated the direct haemodynamic effects of transcatheter embolisation of PAVMs, using non-invasive finger pressure measurements. METHODS: During the procedure, blood pressure, heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and delta pressure/delta time (dP/dt) were continuously monitored using a Finometer®. Potential changes in these haemodynamic parameters were calculated from the pressure registrations using Modelflow® methodology. Absolute and relative changes were calculated and compared using the paired sample t-test. RESULTS: The present study includes 29 HHT patients (mean age 39 ± 15 years, 11 men) who underwent transcatheter embolotherapy of PAVMs. The total number of embolisations was 72 (mean per patient 2.5). Directly after PAVM closure, SV and CO decreased significantly by -11.9 % (p = 0.01) and -9.5 % (p = 0.01) respectively, without a significant change in HR (1.8 %). Mean arterial blood pressure increased by 4.1 % (p = 0.02), while the TPR and dP/dt did not increase significantly (5.8 % and 0.2 %, respectively). CONCLUSIONS: Significant haemodynamic changes occur directly after transcatheter embolisation of PAVMs, amongst which a decrease in stroke volume and cardiac output are most important.

Cone beam CT guidance provides superior accuracy for complex needle paths compared with CT guidance.

OBJECTIVE: To determine the accuracy of cone beam CT (CBCT) guidance and CT guidance in reaching small targets in relation to needle path complexity in a phantom. METHODS: CBCT guidance combines three-dimensional CBCT imaging with fluoroscopy overlay and needle planning software to provide real-time needle guidance. The accuracy of needle positioning, quantified as deviation from a target, was assessed for inplane, angulated and double angulated needle paths. Four interventional radiologists reached four targets along the three paths using CBCT and CT guidance. Accuracies were compared between CBCT and CT for each needle path and between the three approaches within both modalities. The effect of user experience in CBCT guidance was also assessed. RESULTS: Accuracies for CBCT were significantly better than CT for the double angulated needle path (2.2 vs 6.7 mm, p<0.001) for all radiologists. CBCT guidance showed no significant differences between the three approaches. For CT, deviations increased with increasing needle path complexity from 3.3 mm for the inplane placements to 4.4 mm (p=0.007) and 6.7 mm (p<0.001) for the angulated and double angulated CT-guided needle placements, respectively. For double angulated needle paths, experienced CBCT users showed consistently higher accuracies than trained users [1.8 mm (range 1.2-2.2) vs 3.3 mm (range 2.1-7.2) deviation from target, respectively; p=0.003]. CONCLUSION: In terms of accuracy, CBCT is the preferred modality, irrespective of the level of user experience, for more difficult guidance procedures requiring double angulated needle paths as in oncological interventions. ADVANCES IN KNOWLEDGE: Accuracy of CBCT guidance has not been discussed before. CBCT guidance allows accurate needle placement irrespective of needle path complexity. For angulated and double-angulated needle paths, CBCT is more accurate than CT guidance.

Two malignancies or an unusual presentation of a pleural malignancy?

Malignant mesothelioma is primarily located in the pleura. Progression usually involves adjacent tissue invasion. Both lymphatic and haematogenous spreads are possible, but rare. Bone involvement usually means locally invasive disease and rarely bone marrow metastases. In this report we presented two patients with a mesothelioma and bone marrow metastases.

Real-Time 3D fluoroscopy guidance during needle interventions: technique, accuracy, and feasibility.

OBJECTIVE: Real-time 3D fluoroscopy guidance using cone beam CT with dedicated needle path planning software is a promising new interventional technique. The objective of this study was to evaluate the procedure and to assess the accuracy and feasibility of this technique for use in needle interventions. SUBJECTS AND METHODS: All procedures were performed using a flat panel-based fluoroscopy system capable of acquiring cone beam CT images and dedicated needle path-planning software. This new technology allows the use of fluoroscopy coregistered with a 3D data set reconstructed from the acquired attenuation information. The needle trajectory is planned in the 3D data set using the needle path-planning software. The calculated trajectory is then projected on to the real-time fluoroscopy image. Fluoroscopy time, accuracy, technical success of the procedures, median procedure time, and complications were recorded in 145 interventions. RESULTS: One hundred forty-five needle interventions were performed in 139 patients using real-time 3D fluoroscopy guidance. Procedures were divided into five groups according to anatomic region: upper thoracic (n = 19; 13.1%), lower thoracic (n = 18; 12.4%), upper abdominal (n = 65; 44.8%), lower abdominal (n = 13; 9.0%), and musculoskeletal (n = 30; 20.7%). Thirty needle interventions were therapeutic, and 115 were diagnostic biopsies. All interventions were within the predefined 5-mm safety margin and achieved 100% technical success. A histopathologic diagnosis could be made in 91.4% of the diagnostic biopsies. The median interventional procedure time was 28.5 minutes, and the median fluoroscopy time was 2 minutes 58 seconds. There were minor complications in six patients (4.3%) and one major complication (0.7%). CONCLUSION: Real-time 3D fluoroscopy guidance is a new, promising, and feasible technique providing high accuracy in needle interventions.

[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.

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.

[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.

Exclusion of venous thromboembolism: evaluation of D-Dimer PLUS for the quantitative determination of D-dimer.

The objective of this study was to evaluate if D-Dimer PLUS (Dade Behring, USA), a rapid fully automated assay, could be used as an initial screening test in the diagnosis of venous thromboembolism (VTE). Samples from 274 consecutive symptomatic patients with suspected pulmonary embolism (n=229; 79% outpatients, 21% inpatients), deep venous thrombosis (n=37; 84% outpatients, 16% inpatients) or suspected for both complications (n=8) were tested with this D-dimer assay with a Sysmex CA-1500 Coagulation Analyzer. Clinical probability for pulmonary embolism (PE) or deep venous thrombosis (DVT) was staged according to a pretest risk score proposed by Wells. Final diagnosis of PE and/or DVT was established by spiral-computed tomography of the pulmonary arteries or compression ultrasonography, respectively. PE was diagnosed in 13.5% of the patients, whereas DVT was confirmed in 17.7% of the patients. The optimal cut-off value for exclusion of venous thromboembolism was 130 mug/l, and sensitivity, specificity and negative predictive value (NPV) were 95.0% (95% CI: 92.4-97.6), 30.4% (95% CI: 25.0-35.8) and 97.2% (95% CI: 95.2-99.2), respectively. In fact, two patient with PE were missed using D-Dimer PLUS; both cases were outpatients. In conclusion, this assay appears to be safe when implemented in an algorithm based on clinical assessment, D-dimer concentration, and radiological diagnostic techniques to stratify the risk for PE or DVT. However, higher sensitivities and negative predictive values were claimed in the scarce published reports for the D-Dimer PLUS assay than found in this study.

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.

The application of a Dutch consensus diagnostic strategy for pulmonary embolism in clinical practice.

In The Netherlands, the 'Dutch consensus strategy' was formulated in 1993 as a diagnostic strategy for patients with suspected pulmonary embolism. Four years after its introduction, the application of this strategy was investigated. A questionnaire was sent to the hospital management and the departments of internal medicine and pulmonology of all Dutch hospitals. In total, 384 questionnaires were sent out. The response rates of the internists and pulmonologists were 63 and 65%, respectively. The specialists reported to have followed the consensus strategy in 75% of the patients seen the month prior to the questionnaire. However, analysis of only the last patient with the suspicion of pulmonary embolism revealed that the consensus strategy was followed in 55 of the 162 patients. As well, an overuse and an underuse of the different diagnostic facilities was documented. Furthermore almost a quarter of the patients were treated without an ascertained diagnosis, whereas 11% were not treated despite an improper exclusion of venous thrombo-embolism. Compared to a survey in 1994, the use of the 'Dutch consensus strategy' has not improved dramatically. In 34% of the patients, the consensus strategy was strictly followed (i.e. without any additional investigation); however in 67% of the patients a proper diagnosis was achieved. In any diagnostic strategy, two aspects should be considered. First the availability of the different facilities. Second the acceptance of the strategy by the physicians, involved in the diagnosis of patients with clinically suspected pulmonary embolism.

Availability of diagnostic facilities in the Netherlands for patients with suspected pulmonary embolism. ANTELOPE Study Group. Advances in New Technologies Evaluating the Localisation of Pulmonary Embolism.

Pulmonary embolism remains a complex diagnostic problem. Although accurate and cost-effective, the 'Dutch consensus' strategy is not widely applied. We assessed the availability and investment plans of the different facilities used in this strategy. Furthermore, the current and future availability of new diagnostic modalities was investigated. A questionnaire was sent to all Dutch hospitals. The questionnaire contained separate sections with questions for the hospital management and the medical practitioners at the departments of radiology, nuclear medicine, internal medicine and pulmonology. Five hundred and eighty-four questionnaires were sent out (response rate 68%). Forty-three percent of the hospitals had no nuclear medicine facility, 11% had no pulmonary angiography facility, and 59% had no spiral CT scan (SCTA). Forty-six percent of the responding hospitals had a nuclear medicine facility; and 5% used Technegas for ventilation studies. Strategies with SCTA were available in about 27% of the hospitals. Due to future investments this number will increase to approximately 55%. Strategies with Technegas were available in 2.4% of the hospitals, this number might increase to 25% if Technegas is proven accurate. The 'Dutch consensus' strategy is available in two-thirds of the hospitals. All other strategies were less feasible. Several equivalent strategies for diagnosing pulmonary embolism should be developed. These strategies should be accurate, widely available and accepted.

Suspected pulmonary embolism: prevalence and anatomic distribution in 487 consecutive patients. Advances in New Technologies Evaluating the Localisation of Pulmonary Embolism (ANTELOPE) Group.

PURPOSE: To evaluate the prevalence and anatomic distribution of pulmonary embolism (PE) in a group of consecutive patients clinically suspected of having PE. MATERIALS AND METHODS: Four hundred eighty-seven consecutive patients clinically suspected of having PE were examined in six Dutch hospitals from May 1997 through March 1998. Patients underwent ventilation-perfusion (V-P) scintigraphy, spiral computed tomographic (CT) angiography, and/or digital subtraction pulmonary angiography according to a strict diagnostic protocol. Independent readers reviewed all of the diagnostic image studies in centralized readings. The largest pulmonary arterial branch in which PE was detected was recorded. RESULTS: The prevalence of PE was 27% (130 of 487 patients). There was a significant difference in PE size between the high-probability and nondiagnostic V-P scans: The high-probability scans tended to depict larger emboli, but they also showed small subsegmental emboli. Twenty-nine (22%) of 130 patients had subsegmental PE; 23 of these 29 patients had a high-probability V-P scan. CONCLUSION: The largest pulmonary arterial branch with PE was central or lobar in 66 (51%), segmental in 35 (27%), and isolated subsegmental in 29 (22%) patients.