The diagnostic value of light reflection rheology for suspected deep vein thrombosis: a five-and-a-half year single centre experience.

OBJECTIVES: Previous studies evaluating light reflection rheology (LRR) in the preliminary diagnosis of suspected deep vein thrombosis (DVT) have been based on limited patient numbers. The objective of this study was to demonstrate the diagnostic value of LRR in this setting for a large patient series. METHODS: A retrospective study was carried out using prospectively collected data over a five-and-a-half year period. During the study period, 3342 limbs were assessed with LLR in 3105 patients referred with suspected DVT (both inpatients and outpatients). RESULTS: In total, 2396 (71.7%) of all the LRR tests carried out yielded an abnormal result. Of the remaining 946 (28.3%) with a normal result, 204 went on to have a duplex scan due to a high clinical index of suspicion, and 14 DVTs were identified on duplex scanning. Of the remaining 742 patients with a normal LRR result who were not scanned, six re-presented within three months with a confirmed DVT, and one with a confirmed pulmonary embolus (PE). These results yield a negative predictive value of 97.8%, a sensitivity of 96.4% with a three-month post-test thromboembolism incidence of 0.9%. Use of LRR allowed duplex scanning to be avoided for 22.2% of referrals. CONCLUSIONS: Despite the increasing use of D-dimers and clinical probability scoring in the preliminary investigation of thromboembolic events, LRR remains a viable alternative in safely risk-stratifying patients with suspected DVT.

Asymptomatic strictures in femoro-popliteal vein grafts.

Strictures in saphenous vein grafts represent a preventable cause of graft failure, but these lesions may remain undetected by standard clinical methods until occlusion occurs. A study has been undertaken using intravenous digital subtraction angiography (I.V. DSA) to determine the incidence of asymptomatic strictures in a series of femoro-popliteal vein grafts and all lesions detected have been followed-up without treatment to assess their effect on patency rates. Eighty grafts in 69 asymptomatic patients were examined by I.V. DSA at a variable time postoperatively and again after a mean interval of 13 months. At the first examination a total of 30 strictures were found in 22 grafts (27.5%). At the second examination 5 the 22 strictured grafts (22.7%) had occluded. In contrast, only 4 of the 58 non-strictured grafts (6.9%) had occluded and this difference was statistically significant (chi 2 = 4.0 P less than 0.05). Six new strictures were detected, 2 in previously normal grafts and 4 in already strictured grafts, giving a total of 36 lesions altogether. The finding of a 27.5% stricture rate in asymptomatic patients, carrying a 3-fold increase in occlusion risk leads to the conclusion that screening of these grafts is essential. Sixty-five percent of strictures remained stable and asymptomatic, and this indicates that secondary intervention should be on a selective basis.

The Stresst'er ergometer as an alternative to treadmill testing in patients with claudication.

OBJECTIVES: To compare a new pedal ergometer (the Stresst'er) with conventional treadmill examination in patients with leg pain on exercise. DESIGN: Patients presenting with claudication were assessed by standard treadmill test and by the new device in two District General Hospitals. METHODS: Ninety-four subjects were studied. Symptoms induced by both types of exercise were compared. Distance walked on the treadmill was compared to the number of pumps using the Stresst'er. The percentage change in ankle systolic pressure produced by the two tests was compared. RESULTS: Subjective symptoms induced by the tests were similar. Distance walked did correlate with pumps on the ergometer, as did change in systolic pressure. Analysis of a subgroup of 41 cases with receiver operator curve (ROC) tests showed that the new device is sensitive and specific. CONCLUSION: This new device is comparable with treadmill testing, but being easier to use, may have a place in the vascular clinic.