Predicting Post-Thrombotic Syndrome with Ultrasonographic Follow-Up after Deep Vein Thrombosis: A Systematic Review and Meta-Analysis.

BACKGROUND: Post-thrombotic syndrome (PTS) is a common and potential severe complication of deep venous thrombosis (DVT). Elastic compression stocking therapy may prevent PTS if worn on a daily basis, but stockings are cumbersome to apply and uncomfortable to wear. Hence, identification of predictors of PTS may help physicians to select patients at high risk of PTS. AIMS: This article identifies ultrasonography (US) parameters assessed during or after treatment of DVT of the leg, that predict PTS. METHODS: This is a systematic review and meta-analysis study. Databases were searched for prospective studies including consecutive patients with DVT who received standardized treatment, had an US during follow-up assessing findings consistent with vascular damage after DVT and had a follow-up period of at least 6 months for the occurrence of PTS assessed by a standardized protocol. RESULTS: The literature search revealed 1,156 studies of which 1,068 were irrelevant after title and abstract screening by three independent reviewers. After full-text screening, 12 relevant studies were included, with a total of 2,684 analysed patients. Two US parameters proved to be predictive of PTS: residual vein thrombosis, for a pooled odds ratio (OR) of 2.17 (95% confidence interval [CI], 1.79-2.63) and venous reflux at the popliteal level, for a pooled OR of 1.34 (95% CI, 1.03-1.75). CONCLUSION: The US features reflux and residual thrombosis measured at least 6 weeks after DVT predict PTS. Whether these features may be used to identify patients who may benefit from compression therapy remains to be assessed in further studies.

[Normal value of the tracheal bifurcation angle and correlation with left atrial volume]. / Valore normale dell'angolo della biforcazione tracheale e correlazione con il volume dell'atrio sinistro.

PURPOSE: We evaluated the mean value and the variability range of the tracheal bifurcation angle by patient gender, age, height, weight, build, body area and max transverse diameter of the chest under normal conditions. We also evaluated tracheal bifurcation angle changes in orthostatism and recumbency, as well as in the different respiratory phases. Finally, we investigated the statistical correlation between the tracheal bifurcation angle value and the left atrial volume, to eventually derive either value from the other. MATERIAL AND METHODS: We reviewed 700 high-voltage radiographs of the chest performed in 500 patients with normal echocardiographic findings from 1986 to 1990. To analyze the relationships with the left atrium, 100 patients with echocardiographically enlarged atrium were submitted to high-voltage radiography. The tracheal bifurcation angle was measured directly. RESULTS: Mediastinal radiographs nearly always depict the trachea and extraparenchymal bronchi adequately. The tracheal bifurcation angle should be measured continuing and joining the upper and lower parabronchial contours. A 4-degree deviation is accepted between the upper or interbronchial and lower or carinal angles since the angles formed by parallel segments have the same value. Under normal conditions the absolute mean value of the tracheal bifurcation angle was 79.7 degrees and the range 37-105 degrees. DISCUSSION AND CONCLUSIONS: In normal patients the mean value of the tracheal bifurcation angle: is independent of age and gender; depends on build; is related to the max transverse diameter of the chest and to body area; exhibits no major radiographic changes in orthostatism versus recumbency; exhibits no major radiographic changes in expiration versus inspiration; is correlated with left atrial volume, but the value is not statistically significant.