Impedance plethysmography in the diagnosis of asymptomatic deep vein thrombosis in hip surgery. A venography-controlled study

SummaryIn the present study 57 consecutive patients with a first episode of venographically proven deep vein thrombosis were investigated to evaluate the release of tissue-type plasminogen activator (t-PA) and of urokinase-type plasminogen activator (u-PA) in response to DDAVP stimulation as well as the resting plasminogen activator inhibitor (PAI) concentration, comparing this to the results obtained in 66 similar patients with a clinical suspicion of thrombosis but with a normal venogram. All assays were performed without knowledge of the patient's status.Four patients in the deep vein thrombosis-group (7%) had an absent u-PA antigen response upon DDAVP infusion, while a normal response was observed in all control subjects. Patients and controls showed similar increases in t-PA antigen level upon DDAVP. High resting PAI antigen levels were encountered in 5 patients in the deep vein thrombosis-group (9%) and in 6 subjects in the control group (9%).The results from this controlled study indicate that a defective release of u-PA may occur in patients with deep vein thrombosis and may have pathogenetic significance. Furthermore it is concluded that elevation of PAI levels cannot be considered as a specific risk factor for venous thrombosis.

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Confirmation of the Failure of Computerized Impedance Plethysmography in the Diagnostic Management of Patients with Clinically Suspected Deep-Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646500 ◽

1991 ◽

Vol 66 (06) ◽

pp. 744-744

Author(s):

Anthonie W A Lensing ◽

Harry R Büller ◽

Jan Wouter ten Cate ◽

Paolo Prandoni

Keyword(s):

Deep Vein Thrombosis ◽

Impedance Plethysmography ◽

Vein Thrombosis ◽

Diagnostic Management ◽

Deep Vein

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A Comparison of General Anesthesia and Regional Anesthesia as a Risk Factor for Deep Vein Thrombosis Following Hip Surgery: A Critical Review

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647346 ◽

1990 ◽

Vol 64 (04) ◽

pp. 497-500 ◽

Cited By ~ 86

Author(s):

Martin H Prins ◽

Jack Hirsh

Keyword(s):

Deep Vein Thrombosis ◽

General Anesthesia ◽

Regional Anesthesia ◽

Lower Incidence ◽

Hip Surgery ◽

Level Of Evidence ◽

Vein Thrombosis ◽

Postoperative Thrombosis ◽

High Level ◽

Deep Vein

SummaryWe evaluated the evidence in support of the suggestion that the risk of deep vein thrombosis after hip surgery is lower with regional than with general anesthesia. A literature search was performed to retrieve all articles which reported on the incidence of postoperative thrombosis in both fractured and elective hip surgery. Articles were included if the method of anesthesia used was reported and if they used mandatory venography. Based upon the quality of study design the level of evidence provided by a study was graded.In patients who did not receive prophylaxis there were high level studies in elective and fractured hip surgery. All studies showed a statistically significantly lower incidence of postoperative deep vein thrombosis with regional anesthesia (relative risk reductions of 46-55%). There were no direct comparative studies in patients who received prophylaxis. However, between study comparisons did not show even a trend towards to lower incidence of postoperative thrombosis with regional anesthesia.

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Features of Thrombi and Diagnostic Accuracy of Impedance Plethysmography in Symptomatic and Asymptomatic Deep Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649563 ◽

1993 ◽

Vol 70 (02) ◽

pp. 266-269 ◽

Cited By ~ 21

Author(s):

Giancarlo Agnelli ◽

Benilde Cosmi ◽

Stefano Radicchia ◽

Franca Veschi ◽

Enrico Boschetti ◽

...

Keyword(s):

Deep Vein Thrombosis ◽

Diagnostic Accuracy ◽

High Sensitivity ◽

Impedance Plethysmography ◽

Surveillance Programme ◽

Vein Thrombosis ◽

Asymptomatic Patients ◽

High Prevalence ◽

The Mean ◽

Deep Vein

SummaryImpedance plethysmography (IPG) has high sensitivity and specificity in patients with symptomatic deep vein thrombosis (DVT) while it fails to detect asymptomatic DVT. The aim of this study was to determine whether the features of thrombi such as location, size and occlusiveness could explain the different accuracy of IPG in symptomatic and asymptomatic DVT patients. One-hundred and seventeen consecutive outpatients with a clinical suspicion of DVT and 246 consecutive patients undergoing hip surgery were admitted to the study. In symptomatic patients IPG was performed on the day of referral, followed by venography, while in asymptomatic patients IPG was performed as a surveillance programme, followed by bilateral venography.A venography proved DVT was observed in 37% of the symptomatic patients and 34% of the asymptomatic limbs. A significantly higher proportion of proximal DVTs was found in symptomatic patients than in asymptomatic patients (78% vs 46%; p = 0.001). The mean Marder score, taken as an index of thrombus size, was significantly higher in symptomatic patients than in asymptomatic patients (19.0 vs 9.6; p = 0.0001). A significantly higher proportion of occlusive DVTs was observed in symptomatic than in asymptomatic patients (69% vs 36%; p = 0.001).We conclude that the unsatisfactory diagnostic accuracy of IPG in asymptomatic DVT is due to the high prevalence of distal, small and non occlusive thrombi. Such thrombi are unlikely to cause a critical obstruction of the venous outflow and therefore to produce a positive IPG.

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