B. Wolf, D.M. Nichols* and J. L. Duncan[ Departments of General Surgery and * Radiology, Raigmore Hospital, Inverness, UK]
Safety of a Single Duplex Scan to Exclude Deep Venous Thrombosis
Br. Jour. of Sur. Volume 87, No.11, November 2000, Pgs- 1525-1528
Guidelines advocate that a negative ultrasonographic scan needs to be followed by venography, or a repeat scan to detect potentially missed calf vein thrombosis.
This study evaluates whether anticoagulation can safely be withheld on the basis of a single negative duplex scan.
A retrospective analysis of duplex scan reports, case notes and questionnaires returned by general practitioners of patients suspected to have DVT. The main outcome measure was occurrence of an adverse thromboembolic event, a symptomatic DVT or pulmonary embolism, within 3 months of a negative duplex scan.
537 patients had 709 leg scans performed for suspected DVT. Among 352 patients, who had 429 negative leg scans, four possible adverse events were identified. [1.1% per patient and 0.9% per leg] suggesting it is safe to withhold anticoagulation after a single negative scan.