An Evaluation of Impedance Plethysmography and 125I-Fibrinogen Leg Scanning in Patients following Hip Surgery

1989 ◽  
Vol 62 (03) ◽  
pp. 830-834 ◽  
Author(s):  
M K Cruickshank ◽  
M N Levine ◽  
J Hirsh ◽  
A G G Turpie ◽  
P Powers ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Venous Thrombosis ◽  
Sensitivity And Specificity ◽  
Patient Management ◽  
Outcome Measure ◽  
Impedance Plethysmography ◽  
Hip Surgery ◽  
Screening Tests ◽  
Non Invasive ◽  
Combined Use

SummaryVenous thromboembolism is a common post-operative complication in patients following hip surgery. 125I-fibrinogen leg scanning and impedance plethysmography (IPG), are often used in the detection of venous thrombi in such patients. Information on the sensitivity and specificity of these non-invasive tests for the diagnosis of venous thrombosis following hip surgery is relevant for both patient management and for choosing the appropriate outcome measure for clinical trials evaluating new prophylactic regimens.We determined the sensitivity and specificity of the IPG alone, the 125I-fibrinogen leg scan alone, as well as the combined use of the two tests from a retrospective analysis of 685 hip surgery patients who participated in clinical trials of anti-thrombotic prophylaxis. These patients were followed prospectively with non-invasive tests. Bilateral venography was attempted either when one or both screening tests became positive or on day 10-14 post-operatively if both screening tests remained negative. Adequate venography was obtained in 1,010 (73.7%) legs and thrombi were identified in 198 (19.6%) legs.The sensitivities of the IPG and leg scanning were 12.9% and 44.6% respectively; the corresponding specificities were 98.1% and 95.0%. The sensitivity of a positive result on one or both screening tests was 49.6% with a specificity of 93.9%.Therefore, leg scanning and IPG, even in combination, are not sufficiently accurate to be recommended as the only strategy for the diagnosis of venous thrombosis following hip surgery. Venography should be considered in all patients undergoing surveillance testing either when one or both of the screening tests become positive or on day 10-14 if the screening tests remain negative.

Combined use of methylated reprimo cell-free DNA and pepsinogens for noninvasive detection of early gastric cancer.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 27-27
Author(s):  
Alejandra Alarcon ◽  
Wilda Olivares ◽  
Maria Jose Maturana ◽  
Andres Rodriguez ◽  
Oslando Padilla ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Sensitivity And Specificity ◽  
Detection Rate ◽  
Low Grade ◽  
Cell Free Dna ◽  
Predictive Values ◽  
Non Invasive ◽  
Free Dna ◽  
Combined Use ◽  
Potential Biomarker

27 Background: Gastric cancer (GC) has been described as a multistep cascade of precursor lesions such as non-atrophic chronic gastritis (NACG), multiphocal atrophic gastritis (MAG), intestinal metaplasia (IM), low grade dysplasia (LGD) and high grade dysplasia (HGD) leading to early stages of GC (EGC). Currently, no non-invasive biomarkers for this progression are clinically available. We have previously identified a potential biomarker based on methylated Reprimo (RPRM) cell-free DNA (cfDNA) (Clin Cancer Res 2008;14:6264-9). In a cross-sectional study of 1,076 patients, we showed a sensitivity of 70.8% (95% CI: 60.3 to 81.3) and specificity of 74.3% (95% CI: 71.5 to 77) for methylated RPRM cfDNA, to distinguish NACG+MAG+IM+LGD vs HGD+EGC+AGC (Digestive Disease Week 2014 #108). However, the crude detection rate of EGC was only 46.6%. Here, we aim to explore the role of the combined use of methylated RPRM cfDNA and well stablished atrophy biomarkers such as pepsinogens, for non-invasive detection of EGC. Methods: A case-control study was performed including 237 patients (NACG:40; MAG:94; IM:55; LGD:11; HGD:5: EGC:15; AGC:17) scheduled for upper gastrointestinal endoscopy (UGIE). A heparinized venous blood sample was collected and methylated RPRM cfDNA and Immunoassays for Pepsinogen I and II were performed. Positive value was considered if methylated RPRM cfDNA > 0 copies/mL and PG I/II ratio <3.0 were found. Results: Overall sensitivity and specificity for the combined use of methylated RPRM cfDNA and PGI/II to distinguish NACG+MAG+IM+LGD vs HGD+EGC+AGC was 67.5% (95% CI: 50.2% to 81.9%) and 63% (95% CI: 55.9% to 69.7%), respectively. Positive and negative predictive values were 25.2% (95% CI: 17% to 34.9%) and 91.3% (95% CI: 85.3% to 95.4%), respectively. Importantly, crude detection rate for EGC increased from 46.6% to 86.7%. Conclusions: The combined use of methylated RPRM cfDNA and PGI/II reached similar sensitivity and specificity compared to methylated RPRM cfDNA alone to distinguish NACG+MAG+IM+LGD vs HGD+EGC+AGC. However, combined use of methylated RPRM cfDNA and PGI/II significantly improved the detection rate of EGC, a lesion with a curability rate over 95%.

Contact Thermography as a Screening Test for Deep Venous Thrombosis following Major Hip Surgery

1988 ◽  
Vol 29 (6) ◽  
pp. 649-652 ◽  
Author(s):  
L. Kjær ◽  
S. Winter Christensen ◽  
Aa. Vestergaard ◽  
A. Bjerg-Nielsen ◽  
P. Wille-Jørgensen
Keyword(s):  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
No Value ◽  
Screening Test ◽  
False Negative ◽  
Lower Limbs ◽  
Hip Surgery ◽  
Non Invasive ◽  
Negative Results ◽  
False Negative Results

Contact thermography is a non-invasive, easily handled, and inexpensive investigation for the diagnosis of deep venous thrombosis (DVT) in the lower limbs. In this study 56 patients with total hip replacement were screened for DVT by contact thermography, using bilateral ascending phlebography as reference procedure. Examinations were performed on the seventh postoperative day. All thermograms were evaluated blindly and independently at the end of the study. Phlebography revealed unilateral DVT in six patients. Only two had corresponding findings at thermography, giving four false negative results. Moreover, 14 false positive thermograms were found. Based on the number of legs investigated, the nosographic sensitivity and specificity thus were 33 and 87 per cent, respectively. It is concluded that contact thermography is of no value as a screening test for DVT following major hip surgery.

Combined Use of Leg Scanning and Impedance Plethysmography in Suspected Venous Thrombosis

1977 ◽  
Vol 296 (26) ◽  
pp. 1497-1500 ◽  
Author(s):  
Russell Hull ◽  
Jack Hirsh ◽  
David L. Sackett ◽  
Peter Powers ◽  
Alexander G. G. Turpie ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Impedance Plethysmography ◽  
Combined Use

Prevention of Deep Venous Thrombosis in Patients with Acute Spinal Cord Injuries: Use of Rotating Treatment Tables

Neurosurgery ◽  
1987 ◽  
Vol 20 (5) ◽  
pp. 675-677 ◽  
Author(s):  
Daniel M. Becker ◽  
Marco Gonzalez ◽  
Amilcare Gentili ◽  
Frank Eismont ◽  
Barth A. Green
Keyword(s):  
Clinical Trial ◽  
Spinal Cord ◽  
Clinical Trials ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Randomized Clinical Trial ◽  
Spinal Cord Injuries ◽  
Impedance Plethysmography ◽  
Injured Patients ◽  
Spinal Cord Injured

Abstract A randomized clinical trial of 15 patients with acute spinal cord injuries was performed to test the hypothesis that rotating treatment tables prevent deep venous thrombosis in this population. Four of 5 control (nonrotated) patients developed distal and proximal thrombi, assessed by 125I fibrinogen leg scans and impedance plethysmography. In comparison, only 1 of 10 treated (rotated) patients developed both distal and proximal thrombosis (P = 0.007). These results suggest but do not prove that rotating treatment tables prevent the development of proximal deep venous thrombosis in spinal cord-injured patients. Larger clinical trials are needed to confirm this heretofore undocumented benefit of rotating treatment tables.

scholarly journals Sample Size Requirements of Glaucoma Clinical Trials When Using Combined Optical Coherence Tomography and Visual Field Endpoints

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhichao Wu ◽  
Felipe A. Medeiros
Keyword(s):  
Clinical Trials ◽  
Optical Coherence Tomography ◽  
Visual Field ◽  
Sample Size ◽  
Treatment Effect ◽  
Optical Coherence ◽  
Non Invasive ◽  
Combined Use ◽  
Oct Imaging ◽  
Size Estimates

AbstractGlaucoma clinical trials using visual field (VF) endpoints currently require large sample sizes because of the slowly-progressive nature of this disease. We sought to examine whether the combined use of VF testing and non-invasive optical coherence tomography (OCT) imaging of the neuroretinal tissue could improve the feasibility of such trials. To examine this, we included 192 eyes of 121 glaucoma participants seen at ≥5 visits over a 2-year period to extract real-world estimates of the rates of change and variability of VF and OCT imaging measurements for computer simulations to obtain sample size estimates. We observed that the combined use of VF and OCT endpoints led to a 31–33% reduction in sample size requirements compared to using VF endpoints alone for various treatment effect sizes. For example, 189 participants would be required per group to detect a 30% treatment effect with 90% power with combined VF and OCT endpoints, whilst 276 and 285 participants would be required when using VF and OCT endpoints alone respectively. The combined use of OCT and VF endpoints thus has the potential to effectively improve the feasibility of future glaucoma clinical trials.

DIAGNOSIS OF DEEP VENOUS THROMBOSIS: NON-INVASIVE VS INVASIVE DIAGNOSTIC PROCEDURES

1987 ◽  
Author(s):  
J W ten Cate ◽  
M V Huisman ◽  
H R Buller
Keyword(s):  
Clinical Trials ◽  
Reference Method ◽  
Diagnostic Procedures ◽  
Impedance Plethysmography ◽  
Anticoagulant Treatment ◽  
Vein Thrombosis ◽  
Non Invasive ◽  
Deep Vein ◽  
Calf Vein

The clinical diagnosis of deep vein thrombosis (DVT) in symptomatic patients is unreliable. The need for objective diagnostic tests is widely acknowledged. Contrast venography in experienced hands is considered to be the reference method. This method is invasive, uncomfortable to the patient, not easily repeatable and expensive.For this reason several non-invasive tests have been developed and evaluated recently. Of the non-invasive tests impedance plethysmography (IPG) has been thoroughly evaluated in properly designed prospective clinical trials. Serial IPG in symptomatic outpatients is safe and effective. It was shown in longterm follow-up that anticoagulant treatment could be safely withheld in over 500 patients with repeatedly normal IPG (0.3-0.6% recurrence DVT). The specificity for proximal DVT was 92%. The feasability of IPG in symptomatic outpatients was over 95%. The safety of withholding anticoagulant treatment in symptomatic inpatients with a serial normal IPG is an unresolved issue. Preliminary results show that a similar sensitivity might be obtained in inpatients, however, the feasability was lower (87%).Doppler ultrasound has been studied extensively, however, there is a great variation in reported sensitivity for proximal DVT due to the lack of objective diagnostic criteria and the safety of withholding anticoagulant treatment in patients with serial normal Doppler tests results is not es tablished.strain gauge plethysmography has not been evaluated properly and therefore awaits further studies. 125I-fibrinogen legscanning has been shown to be sensitive for calf vein thrombosis (over 90%). In combination with IPG this method is a safe and effective alternative to venography.Radionuclide phlebography has never been evaluated in prospective clinical trials in a broad spectrum of symptomatic patients, and can therefore not be recommended for routine use.It is concluded that presently the management of patients with clinically suspected DVT should be performed with the use of serial IPG, IPG in combination with 125I—fibrinogen legscanning or contrast venog raphy.

Diagnosis Of Deep Venous Thrombosis By Combined Non-Invasive Flow Studies And Coagulation Tests

1981 ◽  
Author(s):  
J A Caprini ◽  
D R Watts ◽  
C A Franck ◽  
A R Crampton ◽  
J P Vagher ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
False Positive ◽  
Impedance Plethysmography ◽  
Non Invasive ◽  
Blood Tests ◽  
Coagulation Tests ◽  
The Face ◽  
Positive Results

The diagnostic accuracy of Doppler ultrasound, impedance plethysmography, activated thrombelastography (TEG), and fibrin split products (FSP) assays were compared to the results of ascending venography in 127 consecutive patients with suspected deep venous thrombosis (DVT). The combination of Doppler with impedance plethysmography was 96% accurate in predicting normal limbs and 83% accurate in identifying limbs harboring thrombi. This combination of flow tests was more sensitive in detecting clots at the popliteal level or above (15/17 88%) than in the calf veins (18/23 78%). The coagulation tests had a high percentage of false positive results (TEG - 39%; FSP - 52%). TEG and FSP combined were 79% (67/87) accurate in normal limbs; 72% (29/40) accurate in those with thrombosis. 0/87 patients had all four tests positive in the face of a normal venogram. 1/40 patients with thrombosis had normal results with all four tests. This patient only had calf clots.These results suggest that the addition of blood tests to flow studies does improve sensitivity and specificity when all tests are either positive or negative. The presence of normal blood tests and flow studies completely excluded thrombi in this series.

Is Quantitative Determination of Fibrin(ogen) Degradation Products and Thrombin-Antithrombin III Complexes Useful to Diagnose Deep Venous Thrombosis in Outpatients?

1989 ◽  
Vol 62 (04) ◽  
pp. 1043-1045 ◽  
Author(s):  
Paul F M M van Bergen ◽  
Eduard A R Knot ◽  
Jan J C Jonker ◽  
Auke C de Boer ◽  
Moniek P M de Maat
Keyword(s):  
Quantitative Determination ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Antithrombin Iii ◽  
Degradation Products ◽  
Family Doctor ◽  
Diagnostic Value ◽  
Impedance Plethysmography ◽  
Fibrin Degradation Products

SummaryWe studied the diagnostic value of recently introduced ELISA’s for the determination of thrombin-antithrombin III (TAT) complexes, fibrin degradation products (FbDP), fibrinogen degradation products (FgDP) and total degradation products (TDP) for deep venous thrombosis (DVT) in plasma of 239 consecutive outpatients, suspected for DVT by their family doctor. DVT was confirmed by impedance plethysmography in 60 patients. Using the 95th percentile range of 42 healthy volunteers the sensitivity for the detection of DVT was: 37% for TAT, 95% for TDP, 92% for FbDP and 90% for FgDP. Specificity was: 88% for TAT, 16% for TDP, 20% for FbDP and 25% for FgDP.We conclude that these assays are of little value in the diagnosis of DVT in outpatients.

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