The Clinical Validity of Normal Compression Ultrasonography in Outpatients Suspected of Having Deep Venous Thrombosis

doi:10.1059/0003-4819-128-1-199801010-00001

The Clinical Validity of Normal Compression Ultrasonography in Outpatients Suspected of Having Deep Venous Thrombosis

From the University of Oklahoma Health Sciences Center and Veterans Administration Medical Center, Oklahoma City, Oklahoma. Acknowledgments: The authors thank Jan Myers, Jay Heath, Cynthia Jones, Debra Cosby (deceased), and Rhonda Traylor for technical assistance with noninvasive testing and data collection. Grant Support: By National Research Service Awards HL 08883 (Dr. Birdwell) and HL 08756 (Dr. Durica) from the National Heart, Lung, and Blood Institute; fellowships from the Presbyterian Health Foundation (Drs. Birdwell and Durica); and a University of Oklahoma College of Medicine Alumni Association Award (Dr. Birdwell). Requests for Reprints: Brian G. Birdwell, MD, Veterans Administration Medical Center (151), 921 NE 13th Street, Oklahoma City, OK 73104. Current Author Addresses: Dr. Birdwell: Veterans Administration Medical Center (151), 921 NE 13th Street, Oklahoma City, OK 73104.

Abstract

Background: Ultrasonography using vein compression accurately detects proximal deep venous thrombosis in symptomatic outpatients. Repeated testing is required for patients with normal results at presentation, but the optimal management of such patients is uncertain.

Objective: To test the safety of withholding anticoagulation in outpatients suspected of having first-episode deep venous thrombosis who have normal results on simplified compression ultrasonography at presentation and on a single repeated test done 5 to 7 days later.

Design: Prospective cohort study.

Setting: Noninvasive vascular laboratories at a university teaching hospital and a Veterans Administration medical center.

Patients: 405 consecutive outpatients suspected of having first-episode deep venous thrombosis.

Intervention: Ultrasonography was performed at presentation. The common femoral and popliteal veins were assessed for compressibility. If the result was normal, anticoagulation was withheld and testing was repeated 5 to 7 days later. Anticoagulation was withheld from all patients whose results remained normal according to compression ultrasonography, regardless of their symptoms. The safety of this approach was tested by follow-up lasting 3 months.

Measurements: Objective testing was done during follow-up in all patients with symptoms or signs of venous thromboembolism. The outcome measure was symptomatic venous thrombosis or pulmonary embolism during follow-up, confirmed by objective testing.

Results: Ultrasonography had normal results in 335 patients (83%) and abnormal results in 70 (17%). None of the patients with normal results died of pulmonary embolism. Venous thromboembolism occurred during follow-up in 2 patients with normal ultrasonographic results (0.6% [95% CI, 0.07% to 2.14%]) and in 4 patients with abnormal results (5.7% [CI, 1.58% to 13.99%]) (P = 0.009).

Conclusions: It is safe to withhold anticoagulation in outpatients suspected of having first-episode deep venous thrombosis if results of simplified compression ultrasonography are normal at presentation and on a single repeated test done 5 to 7 days later.