Validation of the LET classification.

INTRODUCTION: Acute thrombus removal therapies may reduce post-thrombotic syndrome in certain deep venous thrombosis patients. The LET classification is designed to identify patients at high risk for developing post-thrombotic syndrome in the acute phase using thrombus location and extent. This study evaluates the use of the LET classification to predict post-thrombotic syndrome in a cohort of patients after deep venous thrombosis. METHODS: A cohort of 660 deep venous thrombosis patients was invited to participate and fill out a questionnaire with Quality of life questionnaires, basic information, a modified self-assessment version of the Villalta scale for post-thrombotic syndrome and potential confounders. Original data on thrombus extension was available, and the LET classes were determined. Obtained information was analysed using ANOVA and in a multiple logistic regression model to correct for confounders. All different LET classes were compared to post-thrombotic syndrome occurrence, post-thrombotic syndrome prediction and disease specific quality of life scores (VEINES-Sym/Qol). RESULTS: Three hundred and fifteen patients responded, and in 309 a post-thrombotic syndrome score was distilled. LET I,II,III (n = 63) had an odds ratio of 3.4(1.2-9.2) for predicting severe post-thrombotic syndrome, and LET II (n = 17) had an odds ratio of 5.1(1.3-20.8) compared to LET class I (n = 97). Both the VEINES-Sym and VEINES-Qol score were significantly lower for LET I,II,III compared to LET I, and LET II compared to LET I. CONCLUSION: The LET classification can be used to classify patients according to acute thrombus location and extent. Extensive and centrally located (LET I,II,III) deep venous thrombosis showed the highest probability in developing severe post-thrombotic syndrome and lower disease specific quality of life.

Venous in-stent thrombosis treated by ultrasound accelerated catheter directed thrombolysis.

OBJECTIVE/BACKGROUND: Stent placement in the venous system is an increasingly used treatment modality in chronic venous obstruction and as additional treatment after thrombolytic therapy in ilio-femoral deep vein thrombosis (DVT). Experience in treating in-stent thrombosis with ultrasound accelerated catheter directed thrombolysis (UACDT) is reported. METHODS: A retrospective analysis of patients treated for venous stent occlusion, after percutaneous transluminal angioplasty (PTA) and stent placement for either chronic venous occlusive disease or persistent vein compression in patients with acute DVT was performed. Duration of occlusion and suspected clot age were assessed using patient complaints and typical findings on duplex ultrasonography (DUS). DUS and venography were used to assess patency and to determine the cause of re-occlusion. Acute treatment of occlusion was by UACDT. Additional procedures included PTA, stent placement, and creation of an arteriovenous (AV) fistula. RESULTS: Eighteen patients (median age 43 years; 67% male), treated for occluded stent tracts with UACDT between January 2009 and July 2014, were identified. Indications for initial stenting were treatment of chronic venous obstructive disease (12 patients) and treatment of underlying obstruction after initial thrombolysis in acute DVT (six patients). Technical success was achieved in 11/18 (61%) patients. Primary patency in 8/11 patients was 73% at last follow up (median follow up 14 months [range 0-41 months]). Additional treatments after successful lysis were re-stenting (seven patients) and creation of an AV fistula (six patients). CONCLUSION: Treatment with UACDT of recently occluded stent tracts is feasible and effective. Recanalization of the stent tract can be achieved in most cases. Additional interventions were frequently used after successful UACDT treatment. Suboptimal stent positioning caused the majority of the stent occlusions.

Villalta scale: goals and limitations.

The post-thrombotic syndrome (PTS) is a common, debilitating complication following deep venous thrombosis. PTS is a syndrome for which it has been difficult to provide a clear definition. PTS was defined as chronic venous signs/symptoms after a deep venous thrombosis. A number of scales are available to diagnose PTS, but there is a strong need for standardization. The Villalta scale was chosen as the standardized PTS scale. The Villalta scale has been validated in several studies and shows good correlation with generic and disease-specific quality of life scales. The inter-observer rate between study nurses and physicians was shown to be very good. Furthermore, the scale shows good discriminative properties among the different severity groups of PTS. The Villalta scale is useful for use in randomized controlled trials and it allows pooling of data from different studies. The Villalta scale should undergo further validation on intra-rater reliability. Ongoing randomized controlled trials will further validate the Villalta scale for use in PTS.