Michael Reuter

Intravenous pulse cyclophosphamide in the treatment of interstitial lung disease due to collagen vascular diseases.

OBJECTIVE Substantial toxicity limits the use of daily oral cyclophosphamide (CYC) for the treatment of interstitial lung disease (ILD) due to collagen vascular diseases. We examined whether intravenous (i.v.) pulse CYC can be substituted for daily oral therapy. METHODS Six patients with rapidly progressive ILD due to polymyositis, systemic sclerosis, systemic lupus erythematosus, or primary Sjögrens syndrome received 6-9 cycles of i.v. pulse CYC (0.5 gm/m2 of body surface area), together with an initial course of 50 mg of prednisolone, which was tapered to a maintenance dosage of 5-7.5 mg/day, and their response was measured clinically, by high-resolution computed tomography (HRCT) and by assessment of the bronchoalveolar lavage (BAL) cell profile. RESULTS All patients showed significant improvement in exercise tolerance and lung function. Elevated BAL neutrophils dropped substantially, whereas the response of BAL lymphocytes was inconsistent. Low-attenuation opacities in the HRCT regressed in 4 patients and remained unchanged in 2, but reticular infiltrates remained largely unaffected. Remission was maintained with hydroxychloroquine, azathioprine, or cyclosporin A. CONCLUSION I.v. pulse CYC proved to be an effective and well-tolerated treatment in these patients. Since it appears to target mainly the inflammatory component of the disease, it should be reserved for progressive ILD featuring indices of high inflammatory activity.

Mechanical thrombectomy of major and massive pulmonary embolism with use of the Amplatz thrombectomy device.

Müller-Hülsbeck S, Brossmann J, Jahnke T, et al. Mechanical thrombectomy of major and massive pulmonary embolism with use of the Amplatz thrombectomy device. Invest Radiol 2001;36:317–322. rationale and objectives. To evaluate the feasibility of mechanical thrombectomy with the Amplatz thrombectomy device (ATD) in restoring patency of acutely thrombosed pulmonary arteries resulting from pulmonary embolism for the improvement of patient outcome. methods. Mechanical thrombectomy with the ATD (8F) was performed in nine consecutive patients with angiographically documented thrombus in the left or right pulmonary artery resulting from deep vein thrombosis (n = 4) or unknown cause (n = 5). results. The Miller index decreased from 18 to 11. In all patients, the majority of the thrombus in the pulmonary artery was cleared after a mean activation time of the ATD of 367 seconds. Thrombectomy was performed with the ATD alone (n = 4) or with additional long-term fibrinolysis therapy (n = 5) with infusion of recombinant tissue-type plasminogen activator. Pulmonary arterial pressure decreased from a mean of 57 mm Hg before mechanical thrombectomy to 55 mm Hg directly after the procedure and to 39 mm Hg after termination of the recombinant tissue-type plasminogen activator infusion. conclusions. Mechanical thrombectomy with the ATD in patients with minor and major pulmonary embolism is technically feasible and safe. It is a potential alternative to drug-mediated thrombolysis and surgery. However, the incremental benefit of the ATD over conventional treatments could be shown only in a randomized controlled study.

Suspected pulmonary artery disruption after transvenous pulmonary embolectomy using a hydrodynamic thrombectomy device: clinical case and experimental study on porcine lung explants.

Purpose: To use porcine lung explants for reconstructing possible situations in which a vessel wall disruption might have occurred in a patient suffering fatal hemoptysis after pulmonary embolectomy with a hydrodynamic thrombectomy device. Methods: A 76-year-old woman with massive pulmonary embolism underwent transvenous pulmonary embolectomy using a 6-F AngioJet Xpeedior catheter according to manufacturers instructions. While activating the device in the middle lobe artery (∼8 mm diameter), massive and ultimately fatal arterial bleeding occurred through the tracheal tube. Because no autopsy was authorized, an experimental study was designed to examine possible causes for the vessel disruption. Five fresh porcine heart-lung preparations were examined inside a dedicated chest phantom. Access to the pulmonary vessels was provided through catheters inside the right and left ventricular outlets. A low-flow circulation was maintained with an external pump. The 6-F AngioJet thrombectomy device was activated at 42 sites inside vessels from 2 to 10 mm in diameter; in one lung, 8 activations were made after deliberately withdrawing the guidewire. Results: Vessels >6 mm in diameter remained intact. Vessel wall disruption occurred in 4 of 7 vessels between 4 and 6 mm in diameter and in 13 of 14 segmental arteries <4 mm in diameter (regardless of whether or not a guidewire was used). The signs of vessel wall disruption included extravasation of contrast material, arteriovenous fistula, and laceration of distal airspaces with contrast inside the bronchus. Conclusions: The application of this system has to be considered potentially dangerous when activated inside vessels with diameters < 6 mm. The use of this device appears to be safe only inside main branches of the lung vessels at this time. Additional experiments will be required to substantiate these initial results.

Detection of dysbaric osteonecrosis in military divers using magnetic resonance imaging

This was a controlled cross-sectional study to investigate the prevalence of dysbaric osteonecrosis (DON) in military divers. MRI examinations of the large joints and adjacent bones were performed in a cross-sectional group of 32 highly experienced military divers and 28 non-divers matched for age and anthropometric data. Additional plain radiographs and follow-up controls were performed in all persons with signs certain or suspicious of DON. In two subject groups (one of divers and one of non-divers), lesions characteristic of DON were detected. From this controlled study, it may be concluded that MRI is a highly sensitive method to detect signs of osteonecrosis. It could be shown that the prevalence of bone lesions characteristic of osteonecrosis in highly experienced military divers is not higher than in non-diving subjects of comparable age. The outcome of this comparably small study group fits to the results of previous extensive studies performed with radiographs. The detected low incidence of DON in this collective may be due to the fact that military divers follow stricter selection criteria, decompression schemes and medical surveillance than commercial divers.

Atopy, Airway Reactivity and Compressed Air Diving in Males

A decline in expiratory flow rates in divers has recently been attributed to chronic exposure to hyberbaric air. Airway hyperresponsiveness (AHR) to stimuli due to a hyperbaric environment may play a certain role in this context. The aim of this study was to determine the prevalence of AHR in compressed air divers and to assess the value of bronchial challenges for prediction of fitness to dive. A cross-sectional sample of 59 healthy male volunteers – 28 divers and 31 diving candidates (controls) – who had been found fit to dive in a diving medical examination underwent additional allergy screening (skin prick and serum IgE) and a histamine bronchial challenge. Pre- and postchallenge body plethysmography was completed to assess AHR. AHR to histamine was significantly increased among divers and positively related to diving experience whereas divers and controls did not differ significantly with respect to age, anthropometric data, current smoking habits, skin prick reaction, and elevated serum IgE. Our results indicate an increased prevalence of AHR to nonspecific inhalation stimuli in experienced divers. Bronchial challenge tests may be helpful to detect asthmatics in the medical assessment of fitness to dive and for follow-up examinations during a diver’s career.

In vivo P-31-MR-spectroscopy of focal hepatic lesions. Effectiveness of tumor detection in clinical practice and experimental studies of surface coil characteristics and localization technique.

RATIONALE AND OBJECTIVESThe influence of partial tumor sampling in a volume of interest (VOI) on the ratios of phosphorus metabolites was examined by localized phosphorus magnetic resonance spectroscopy (P-31-MRS). Experiments were performed to investigate the characteristics of the surface coil used and precession of spatial localization. METHODSA total of 24 patients with liver metastases and 20 volunteers were studied by P-31-MRS. Patients were divided in two groups: VOI < 50% (n = 8) and VOI > 50% (n = 16) occupied by tumor. For evaluation of the surface coil and localization method (image selected in vivo spectroscopy), phantom studies were performed. RESULTSSuperficial focal liver tumors were detectable with a surface coil at a distance within the coil radius. The image selected in vivo spectroscopy permitted the study of phosphorus metabolism in a defined VOI. phosphomonoester/β-adenosine triphosphate and phosphodiester/β-adenosine triphosphate were elevated significantly in spectra of both patient groups.CONCLUSIONS. Detection of small tumor volumes within a VOI filled by less than 50% of the tumor is possible, with results statistically different from that in normal volunteers.