Featured Research

from universities, journals, and other organizations

Simpler Diagnostic Method May Be As Effective At Detecting Blood Clot In The Leg

Date:
October 16, 2008
Source:
JAMA and Archives Journals
Summary:
A comparison of two diagnostic methods used to detect deep vein thrombosis (DVT; a blood clot in a deep vein in the leg or thigh) of the lower extremities indicates that a simpler method, with wider availability, has rates of DVT detection that are equivalent to a more complex method, according to a new study.

A comparison of two diagnostic methods used to detect deep vein thrombosis (DVT; a blood clot in a deep vein in the leg or thigh) of the lower extremities indicates that a simpler method, with wider availability, has rates of DVT detection that are equivalent to a more complex method, according to a new study.

The imaging technique, compression ultrasonography, is a highly accurate method for the detection of DVT and has replaced other diagnostic methods in common practice. Two ultrasonography diagnostic methods often used are 2-point and whole-leg. With 2-point ultrasonography, compression is applied to two veins, and benefits include simplicity, reproducibility and broad availability (may be performed with virtually all ultrasound scanners, irrespective of age or model). "Its major limitation is the need to repeat the test once within 1 week in patients with normal findings at presentation to detect calf DVT extending to the proximal [near the point of origin] veins. Repeat testing may be safely avoided in patients with a normal D-dimer test [blood test used to help rule out active blood clot formation] at presentation," the authors write.

The advantages of whole-leg ultrasonography include the ability to exclude isolated calf DVT, allowing for 1-day treatment of all patients, without additional testing. Conversely, it needs top-quality ultrasound equipment and experienced operators; therefore, it is often unobtainable after hours and during the weekends. Despite the lack of definite evidence, whole-leg ultrasonography is thought to be better than serial 2-point ultrasonography, and as a consequence, many patients with suspected DVT need to wait hours or even days before whole-leg ultrasonography is obtained and are frequently (unnecessarily) administered anticoagulants in the meantime, according to background information in the article.

Enrico Bernardi, M.D., Ph.D., of the Civic Hospital, Conegliano, Italy, and colleagues conducted a study to determine if the two diagnostic strategies are equivalent for the treatment of patients with suspected DVT of the lower extremities. The randomized, multicenter study included 2,098 outpatients with a first episode of suspected DVT of the lower extremities who were randomized to undergo 2-point (n = 1,045) or whole-leg (n = 1,053) ultrasonography.

Of patients in the 2-point strategy group, the incidence of confirmed symptomatic venous thromboembolism (VTE; blood clots in the deep veins of the legs or in the lungs) during the 3-month follow-up period was 0.9 percent (7 of 801 patients). Of patients randomized to the whole-leg ultrasonography method, the incidence of confirmed symptomatic VTE during the follow-up period was 1.2 percent (9 of 763 patients).

"The observed difference between the 2 groups in terms of symptomatic VTE at the end of the 3-month follow-up period was 0.3 percent, which is within the chosen equivalence limit" the authors write. "Either strategy may be chosen based on the clinical context, on the patients' needs, and on the available resources. [Two-point ultrasonography plus D-dimer] is simple, convenient, and widely available but requires repeat testing in one-fourth of the patients. [Whole-leg ultrasonography] offers a 1-day answer, desirable for patients with severe calf complaints, for travelers, and for those living far from the diagnostic service, but is cumbersome, possibly more expensive, and may expose patients to the risk of (unnecessary) anticoagulation."

Editorial: Noninvasive Diagnosis of Deep Vein Thrombosis

In an accompanying editorial, C. Seth Landefeld, M.D., of the University of California, San Francisco, San Francisco Veterans Affairs Medical Center, and Stanford University, Stanford, Calif., comments on the findings of Bernardi and colleagues.

"How should clinicians approach patients with a possible first episode of DVT? Based on the available evidence, it would be reasonable to choose 2 tests initially—a clinical prediction rule and D-dimer test, a clinical prediction rule and 2-point ultrasonography, or 2-point ultrasonography and a D-dimer test. If both tests are negative, DVT is effectively ruled out and anticoagulation can be withheld safely."

"If DVT is not ruled out, 2-point ultrasonography should be performed if not already performed. If DVT has neither been ruled out nor diagnosed by ultrasound, a second ultrasound should be performed 1 week later; if that ultrasound is negative for DVT, no further testing is indicated. The results of the trial by Bernardi et al show that whole-leg ultrasonography has little advantage, unless a course of anticoagulant therapy for isolated calf DVT is preferable to repeating 2-point ultrasonography a week later."


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bernardi et al. Serial 2-Point Ultrasonography Plus D-Dimer vs Whole-Leg Color-Coded Doppler Ultrasonography for Diagnosing Suspected Symptomatic Deep Vein Thrombosis: A Randomized Controlled Trial. JAMA The Journal of the American Medical Association, 2008; 300 (14): 1653 DOI: 10.1001/jama.300.14.1653

Cite This Page:

JAMA and Archives Journals. "Simpler Diagnostic Method May Be As Effective At Detecting Blood Clot In The Leg." ScienceDaily. ScienceDaily, 16 October 2008. <www.sciencedaily.com/releases/2008/10/081007172814.htm>.
JAMA and Archives Journals. (2008, October 16). Simpler Diagnostic Method May Be As Effective At Detecting Blood Clot In The Leg. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2008/10/081007172814.htm
JAMA and Archives Journals. "Simpler Diagnostic Method May Be As Effective At Detecting Blood Clot In The Leg." ScienceDaily. www.sciencedaily.com/releases/2008/10/081007172814.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins