Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN.

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.

Feasibility of photoelectron sources with sharp lines of stable energy between 20 and 80 keV.

Photo-absorption of γ-rays in thin Al, Co, Ti, and Mo convertors was examined with the aim to produce quasi monoenergetic photoelectrons having an energy spread of 0.5-4.7eV about mean kinetic energies at discrete values between 18632 and 80321eV. The photoelectron rates were estimated for commercial photon sources of (241)Am, (119m)Sn, (125m)Te and (109)Cd with activities of 0.55-3.7GBq. Photoelectrons ejected by (241)Am γ- and X-rays from Co convertors were measured with two different electron spectrometers and obtained energy spectra were compared with Monte Carlo predictions.

Quantification of elastic recoil after balloon angioplasty in the iliac arteries.

PURPOSE: Elastic recoil of the arterial wall has been shown to be responsible for a significant loss of luminal area after balloon angioplasty in the coronary arteries, but it has not been well studied in the peripheral arteries. Because elastic recoil depends on the presence of elastin in the arterial wall, and the amount of elastin varies by artery and proximity to the aorta, the importance of this response to angioplasty may be different in peripheral arteries. The purpose of this study is to document the degree of elastic recoil in the iliac arteries, and analyze variables that might influence the results. MATERIALS AND METHODS: A series of 19 patients with 25 iliac artery stenoses underwent balloon angioplasty followed by placement of a Palmaz stent with the same-sized angioplasty balloon. The minimum luminal diameter of the lesion was measured before treatment, immediately after balloon angioplasty, and again after stent placement. The arterial diameter after stent placement was defined as the diameter of the inflated balloon. The degree of recoil was correlated with nine variables: patient age and sex, lesion location and length, lesion severity (as percent stenosis), the balloon:artery ratio, and three factors related to lesion morphology--complex versus simple, eccentric versus concentric, and calcified versus noncalcified. RESULTS: Elastic recoil averaged 36% +/- 11% and ranged from 19% to 54% in this series of patients. The only variable that significantly influenced the degree of elastic recoil was the balloon:artery ratio (P =.039), which was directly related. CONCLUSION: Elastic recoil is a significant limitation of balloon angioplasty in the iliac arteries. This study illustrates the importance of techniques that limit recoil, such as vascular stents, in angioplasty of the iliac arteries.

A validation of the 10-meter incremental shuttle walk test as a measure of aerobic power in cardiac and rheumatoid arthritis patients.

OBJECTIVE: To validate a simple, clinically relevant, and inexpensive test of aerobic power-the 10-meter incremental shuttle walk test (SWT)--in 2 separate patient populations. DESIGN: Two-sample validity study. SETTING: Physiotherapy department of major hospital in the United Kingdom. PATIENTS: Convenience samples of rheumatoid arthritis (RA) patients (n = 10) and cardiac patients (n = 10). INTERVENTION: Subjects were attached to a portable respiratory gas analyzer to measure oxygen uptake. They walked around an oval 10-meter course, starting at 0.5m/s, with velocity gradually increased by .17m/s increments for as long as they could, for up to 12 minutes. MAIN OUTCOME MEASURES: A subject's maximal rate of oxygen uptake during exercise (V(O)(2)max) established with linear extrapolation was regressed against the number of shuttles completed (distance walked). An earlier study (n = 28) showed high levels of reliability and validity with linear extrapolation. RESULTS: No significant linear relationship was found between V(O)(2)max and the number of shuttles completed (R(2); RA subjects = 9.7%, cardiac subjects = .03%, p > .05). CONCLUSION: These results do not support use of the SWT as a representative measure of aerobic power. Despite this finding, the advantages of developing a clinically viable alternative to costly laboratory testing warrants further study of the SWT in patient groups.

Accuracy and safety of carbon dioxide inferior vena cavography.

PURPOSE: The purpose of this study was to assess the accuracy of carbon dioxide compared to iodinated contrast material for determining inferior vena cava (IVC) diameter prior to filter placement, and to assess the safety of CO2 when used for this purpose. PATIENTS AND METHODS: Consecutive patients undergoing inferior vena cavography prior to filter placement were prospectively evaluated with use of both CO2 and iodinated contrast material. The diameter of the IVC was measured and compared in the same four locations in each patient for both agents. The diameter was corrected for magnification and pin-cushion distortion. The ability of CO2 to correctly classify IVC diameter as < or =28 mm or >28 mm, based on the IVC diameter with iodinated contrast material, was determined. A consensus panel assessed renal vein visualization with CO2 and iodinated contrast material. Blood pressure and arterial oxygen saturation were measured immediately before and after CO2 injection. RESULTS: Among 30 patients, there was no significant difference in the measured diameter of the IVC with CO2 versus iodinated contrast material after correction for magnification and pin-cushion distortion. One of 30 patients (3.3%) in this study was misclassified as having an IVC < or =28 mm with CO2 when, in fact, the IVC diameter was >28 mm based on iodinated contrast material. This could be clinically significant for certain IVC filters. Forty-seven percent of renal veins identified on contrast venography were identified by CO2 vena cavography. There was no significant difference in the blood pressure or oxygen saturation values measured before and after CO2 injection. However, one patient with pulmonary artery hypertension did experience transient, symptomatic hypotension after CO2 injection. CONCLUSIONS: In most patients, CO2 vena cavography accurately evaluated IVC diameter prior to filter placement. In 3.3% of patients, the discrepancy in measurements between CO2 and iodinated contrast material could be clinically significant, depending on the type of filter placed. CO2 was less accurate than iodinated contrast material in identifying renal veins. Although CO2 vena cavography is safe in the majority of patients, it should be used with caution in patients with pulmonary hypertension.

Intravascular ultrasound as an alternative to positive-contrast vena cavography prior to filter placement.

PURPOSE: In a nonconsecutive series of patients, intravascular ultrasound (IVUS) was investigated for safety and efficacy as an alternative to positive-contrast vena cavography for evaluating the inferior vena cava (IVC) prior to filter placement. MATERIALS AND METHODS: In a 6.5-year period, 30 patients (15 women, 15 men) ranging in age from 22 to 98 years old (mean, 56 years) underwent vena cava filter placement without conventional positive-contrast vena cavography, after IVUS evaluation of the IVC with use of a 6.2-F, 12.5- or 20-MHz monorail catheter system. The rationale for using IVUS included contraindications to iodinated contrast material in 14 patients with renal insufficiency and in four patients with previous life-threatening anaphylactoid reaction to iodinated contrast material; limitations to radiation exposure in four pregnant patients; and inability to otherwise image the IVC of eight morbidly obese patients who exceeded the weight limits of available angiographic equipment. IVUS completely replaced positive-contrast vena cavography, although not fluoroscopy in the four pregnant patients and in the 18 patients with contrast material contraindications. In two of the eight obese patients, IVUS was the only imaging modality. RESULTS: In all 30 patients, IVUS successfully determined the patency of the filter delivery route veins and the vena cava, the absence of thrombus, the location of renal veins, the absence of anatomical variants, and the vena cava diameter at the desired filter deployment level. Successful filter placement was confirmed in all 30 patients either with plain film alone (n = 12), IVUS alone (n = 3), computed tomography alone (n = 1), external ultrasound alone (n = 1), IVUS and another imaging modality (n = 10), or by combinations of other imaging modalities (n = 3). There were no complications. CONCLUSIONS: IVUS is a safe and effective alternative to conventional positive-contrast vena cavography for imaging the IVC prior to filter placement in patients with contraindications to iodinated contrast material or ionizing radiation.

Feasibility of three-dimensional intravascular ultrasonography: preliminary clinical studies.

The aim of this study was to demonstrate the clinical utility of reconstructed three-dimensional intravascular ultrasonography using a voxel-based volume rendering technique. Three-dimensional reconstruction of intravascular ultrasonographic data was performed in 12 patients with various vascular abnormalities during interventional radiology procedures. A stepping motor device was used to pull either a 12.5 or a 20 MHz catheter-based transducer through the lumen of a variety of vessels at a rate of 1.5 mm/s. Images were downloaded to a Life Imaging System for three-dimensional reconstruction. The value of three-dimensional ultrasonographic imaging was evaluated in comparison to conventional intravascular ultrasonography. A variety of abnormalities were demonstrated in reconstructed three-dimensional ultrasound imaging, including arterial atheroma and plaque, aneurysm and pseudoaneurysm, aortic dissection and stenosis (May-Thurner syndrome). The vascular branches and accessory vessels, as well as their relationships to each other, were easily demonstrated on three-dimensional imaging by selecting an appropriate angle, plane, and section of the image. The dimensions and shapes of the vascular lumen were determined in the longitudinal view. Three-dimensional information proved useful for determining the distribution and type of plaque in vessels. Reconstructed three-dimensional imaging allows for global evaluation of the dissection entry site, extent of the flap, and the false lumen of a pseudoaneurysm. Intravascular three-dimensional ultrasonography provides information complementary to that obtained with two-dimensional imaging. It supplies information about spatial relationships of anatomic structures that cannot be evaluated using conventional imaging methods.

Placenta accreta: comparison of cases managed with and without pelvic artery balloon catheters.

OBJECTIVE: To describe our experience with the use of prophylactic pelvic artery balloon catheters in cases of placenta accreta diagnosed by antenatal ultrasound and to compare these cases with contemporary controls. METHODS: In this prospective study, all patients seen at our institution between January 1994 and August 1997 with the antenatal sonographic diagnosis of placenta accreta were offered prophylactic preoperative pelvic artery balloon catheterization. Patients who were delivered by cesarean hysterectomy for unsuspected placenta accreta in our institution during the same time interval served as controls. Five patients with the sonographic diagnosis of placenta accreta underwent prophylactic pelvic artery balloon catheterization. Surgical outcomes in patients who received balloon catheters were compared with those managed without them. Statistical analysis was performed using the Mann-Whitney U test. RESULTS: Five patients with placenta accreta or one of its variants were correctly identified with antenatal ultrasonography. Of the five patients who underwent pelvic artery balloon catheterization, all had placenta accreta and four required cesarean hysterectomy. The mean estimated blood loss, transfusion requirement, and length of hospitalization in patients undergoing hysterectomy managed with and without the balloon catheters was not different (P > 0.06). CONCLUSIONS: Antenatal sonographic diagnosis of placenta accreta enables preoperative planning. In our experience, use of pelvic artery balloon occlusion catheters in patients requiring a cesarean hysterectomy for placenta accreta did not improve surgical outcomes compared with patients managed without them. These preliminary findings are based on a small number of patients; therefore, further investigation is needed.

Carbon dioxide as a contrast agent to guide vascular interventional procedures.

OBJECTIVE: The purpose of this study was to assess the value and limitations of carbon dioxide (CO2) as a contrast agent to guide vascular interventional procedures. SUBJECTS AND METHODS: Twenty-two adults underwent 26 vascular interventional procedures (21 arterial, five venous). We aimed to use only CO2 if possible because these patients had renal insufficiency (n = 21; mean creatinine level, 2.8 mg/dl) or were allergic to contrast material (n = 1). Arterial procedures performed included renal angioplasty or stent (n = 6), iliac angioplasty or stent (n = 5), infrainguinal angioplasty (n = 5), arterial bypass graft angioplasty (n = 3), and thrombolysis (n = 2). Venous procedures included transjugular intrahepatic portosystemic shunt recanalization (n = 3), angioplasty of the venous anastomosis of a thigh dialysis graft (n = 1), and angioplasty of the inferior vena cava (n = 1). RESULTS: Twenty-five of the 26 procedures were successfully performed. Of the 26 procedures, eight required no iodinated contrast material and 11 required less than or equal to 20 ml of contrast material. CO2 proved to be inadequate for the remaining seven procedures. Iliac artery angioplasty or stent placement required an average of 9 ml of iodinated contrast material; infrainguinal angioplasty required an average of 22 ml of iodinated contrast material. CONCLUSION: CO2 can be successfully used as a contrast agent in a variety of vascular interventional procedures. Such procedures can usually be performed in the iliac and infrainguinal arteries using minimal supplemental iodinated contrast material. However, CO2 failed to provide satisfactory guidance in half of the intraabdominal procedures in our study.

1998 SCVIR Gary J. Becker Young Investigator Award. Endovascular repair of arterial pseudoaneurysms with use of a perfusion balloon catheter.

PURPOSE: Pseudoaneurysms represent contained disruption of the arterial wall. Iatrogenic pseudoaneurysms frequently complicate complex endovascular procedures. With use of an animal model, the authors attempted to determine the safety and efficacy of using a perfusion balloon catheter (PBC) to thrombose surgically created pseudoaneurysms. MATERIALS AND METHODS: An in vitro system measured maximum flow volume through a 5-F PBC. Pseudoaneurysms were created in domestic swine with use of a jugular vein patch anastomosed to a femoral arteriotomy. The PBC was inflated across the pseudoaneurysm neck for 30-minute intervals until thrombosis was confirmed by ultrasound. Completion arteriography was performed to evaluate for vascular complications. RESULTS: Maximum flow through the PBC was 62.6 mL/min measured at a constant pressure gradient of 120 mm Hg. Five pseudoaneurysms were created in four animals. The PBC completely thrombosed all five lesions. The mean treatment duration was 129 minutes (+/- 39 minutes SD). No native arterial injury, in situ thrombus, or distal embolization occurred. Partial recanalization of three of the five treated pseudoaneurysms was identified on follow-up arteriography and gross sectioning (n = 2 and n = 1, respectively). CONCLUSION: The PBC safely and effectively thrombosed surgically created pseudoaneurysms. Partial recanalization of treated pseudoaneurysms was demonstrated. Clinical trials are warranted.

Comparison of conventional angioplasty with the Palmaz stent in the treatment of abdominal aortic stenoses from the STAR registry. SCVIR Transluminal Angioplasty and Revascularization.

PURPOSE: To retrospectively compare the safety and short-term efficacy of conventional percutaneous transluminal angioplasty (PTA) and PTA with the Palmaz balloon-expandable intravascular stent for the treatment of infrarenal abdominal aortic atherosclerotic stenoses. PATIENTS AND METHODS: The records of 25 patients with infrarenal aortic stenoses treated by means of percutaneous techniques were retrieved from the SCVIR Transluminal Angioplasty and Revascularization (STAR) Registry and analyzed. Thirteen patients were treated with PTA alone and 12 were treated with the Palmaz intravascular stent. RESULTS: Technical success was achieved in 92% of patients treated with PTA alone and in 100% of those treated with the Palmaz stent. Significant improvements in lesion morphology, hemodynamics, clinical status, and ankle arm indexes were shown in both groups. There was no statistically significant difference in percent stenosis reduction, decrease in trans-stenotic gradient, or initial clinical outcome between the group treated by means of PTA and the group treated by means of PTA with the Palmaz stent. CONCLUSIONS: PTA and intravascular stent placement of atherosclerotic stenoses involving the infrarenal aorta are both safe and efficacious therapeutic modalities. At present, it does not appear that primary stent placement confers any short-term benefits over technically successful PTA in aortic stenoses.

Biliary-pleural fistulas without biliary obstruction: percutaneous catheter management.

OBJECTIVE: Our purpose was to report the use of percutaneous catheter drainage as a therapeutic option in the management of three patients with biliary-pleural fistulas without biliary obstructions. CONCLUSION: In the proper clinical setting, the CT findings of liver dome laceration or abscess, diaphragm disruption, and pleural effusion should suggest biliary-pleural fistula. Percutaneous catheter management can be curative or serve a temporizing function before surgery.

Evaluation of a new percutaneous stainless steel Greenfield filter.

PURPOSE: To evaluate a new percutaneous Greenfield filter with an alternating hook design and over-the-wire delivery system. MATERIALS AND METHODS: The alternating hook stainless steel Greenfield filter was evaluated in a prospective clinical trial between March 10, 1994, and January 27, 1995. Filters were placed in 75 patients in nine clinical centers and follow-up with radiographs and ultrasound scans was carried out at 30 days. RESULTS: Clinical trial results revealed successful placement in all patients. There were four cases of filter limb asymmetry (5.3%) without clinical sequelae, with one incidence of failure to span the cava. No significant migration was found. There were no clinically suspected pulmonary emboli, but one instance of probable caval penetration (1.7%) did occur. Caval occlusion was documented in three patients (5%). CONCLUSION: The percutaneous stainless steel Greenfield filter provides ease of insertion and improved deployment while maintaining the high standards of efficacy and safety associated with the standard and titanium Greenfield filters.