Exclusion and Diagnosis of Deep Vein Thrombosis by a Rapid ELISA D-dimer Test, Compression Ultrasonography, and a Simple Clinical Model

Abstract

The classical clinical signs of deep vein thrombosis (DVT) are unspecific and may be found in several other conditions besides DVT. Therefore, patients suspicious of DVT are subjected to elaborate invasive or noninvasive evidence-based procedures that actually confirm DVT in only 20% to 30% of patients in this setting. However, simple laboratory tests and noninvasive strategies to exclude and diagnose DVT are becoming available in the clinical emergency setting of outpatients. In the presented literature, a sound basis is provided for quantifying clinical judgment for the diagnosis of acute proximal DVT. The number of positive clinical findings at time of first suspicion of DVT appears to correlate directly with the probability of acute proximal DVT. The modified clinical model of Landefeld and Wells for DVT allows reasonable accurate classification of patients into low, moderate, and high probability for suffering DVT. The rapid automated enzyme-linked immunoabsorbant assay (ELISA) VIDAS D-dimer presently available can be rapidly performed in daily practice and emergency situations and is accurate to a high degree, especially in ruling out ongoing venous thromboembolic processes. The sequential use of the rapid ELISA VIDAS D-dimer test and compression ultrasonography in a well-designed clinical setting using a simple clinical model predicts a significant improvement due to a high sensitivity near 100% for the exclusion and diagnosis of DVT in the majority of outpatients with suspect DVT. A prospective decision analysis management study is proposed to exclude and diagnose DVT based on the rapid ELISA VIDAS D-dimer test and compression ultrasonography within the context of a ready-to-use simple clinical model. The proposed simple model of a rational diagnosis of deep vein thrombosis (RADIA DVT) has to be tested in a large multicenter study of more than 1,000 outpatients with suspected DVT. This model would be less expensive, easy to perform, and likely yield a significant simplification and improvement of highly accurate evidence-based exclusion or diagnosis of DVT on the basis of which clear-cut indications of anticoagulation could be appropriately initiated or safely withheld.

Screening for Deep Vein Thrombosis and Pulmonary Embolism in Outpatients with Suspected DVT or PE by the Sequential Use of Clinical Score: A Sensitive Quantitative D-Dimer Test and Noninvasive Diagnostic Tools

“…Phlebography is invasive, is inconclusive in 4 to 12% of cases, overlooks alternative diagnoses like Bakers cyst, and is not available in most hospitals. 1,2 A normal venogram of the leg veins in patients with suspected DVT excludes both proximal and distal DVT irrespective of clinical score on the basis of which anticoagulant treatment can safely be withheld. There are only two small prospective studies on the safety of phlebography to exclude DVT.…”

“…3,4 These data are very close to our working hypothesis for the requirement of a consensus strategy, which should be based on an overall posttest VTE incidence of less than 1%. 1,2 Due to its invasive nature and associated shortcomings and side effects, contrast phlebography has not become a routine test in daily practice for proximal DVT and has been replaced by compression ultrasonography. 1,2,[5][6][7] DIAGNOSIS AND EXCLUSION OF DVT BY COMPRESSION ULTRASONOGRAPHY Compression ultrasonography (CUS) has many advantages over phlebography.…”

“…1,2 Due to its invasive nature and associated shortcomings and side effects, contrast phlebography has not become a routine test in daily practice for proximal DVT and has been replaced by compression ultrasonography. 1,2,[5][6][7] DIAGNOSIS AND EXCLUSION OF DVT BY COMPRESSION ULTRASONOGRAPHY Compression ultrasonography (CUS) has many advantages over phlebography. 1,2,[5][6][7] It is noninvasive, simple, easy to repeat, free of complications, and relatively inexpensive.…”

“…The annual incidence of a first suspicion of deep vein thrombosis (DVT) has been estimated at 2 to 4 per 1000 inhabitants per year. 1,2 This suggests that $ 3000 to 4000 patients per 1 million inhabitants are to be investigated each year for suspected DVT and about one third ($ 1000 per 1 million inhabitants) will indeed have DVT by objective imaging techniques. Clinical assessment and objective testing for the diagnosis of DVT are of huge importance because proximal DVT is life-threatening and can be treated effectively.…”

“…The requirements for a safe diagnostic strategy should be based on an overall posttest incidence of VTE of less than 1% during 3-month follow-up. 1,2 A posttest incidence of DVT of 1% implicates that 1% of 1000 DVTs per 1 million inhabitants are still be overlooked each year.…”