Deep vein thrombosis: recurrences were detected on ultrasound.

Clinical bottom line (level 1b)

A third of patients with suspected recurrent deep vein thrombosis had one.
An ultrasound scan can probably diagnose and exclude it, though a confirmatory venogram may be necessary.

Prandoni et al: Circulation 1993; 88 (1): 1730-1735

Expires May 2003

The study

Setting: university hospital, Italy

145 patients (aged range 18 to 87 years; mean 63, 55% female) suspected recurrent proximal deep vein thrombosis. Had blinded ultrasound scans of common femoral and popliteal veins every three months for one year

Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:

venogram

Diagnostic test: ultrasound scan- positive if veins non-compressible or 2mm or more increase in clot diameter from last measurement

The evidence

pre-test probability of deep vein thrombosis: 95%, (95% CI: 20% to 56%)

diagnostic test	DVT	no DVT	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
ultrasound scan	10	0	inf (3.5 to inf)	100%	0.091 (0.014 to 0.59)	5%
total	11	18

Kappa for scan = 0.95

30% of ultrasound scans were normal at one year.

Citation

Prandoni P, Cogo A, Bernardi E, et al: A simple ultrasound approach for detection of recurrent proximal-vein thrombosis. Circulation 1993; 88 (1): 1730-1735

Contributor: Chris Ball and Clare Wotton, May 2000
Reviewer:

_{Clinical Question.}

_Patient	_{suspected DVT}
_{Intervention or Exposure}	_{ultrasound scan}
_Comparison	_venogram
_Outcome	_diagnosis