Angioscopy: Direct visualization of chronic venous occlusion, May-Thurner syndrome, and other applications in phlebology.

BACKGROUND: Angioscopy has been widely used in the diagnosis and management of vascular disorders and in particular in coronary artery disease. However, few applications have been developed in the diagnosis or management of venous disease. METHODS: Endovenous angioscopy was performed to explore applications of this modality in phlebology. Procedures were performed in a sterile setting. Access was obtained by ultrasound guidance and a 9F introducer sheath. An 8.5F videoscope was used to visualize target veins. Continuous saline irrigation was used to displace blood and to clear the visual field. RESULTS: Fifteen procedures were performed. We describe diagnostic or interventional applications of endovenous angioscopy that include diagnosis and characterization of chronic venous occlusion, deployment of venous stents, angioscopy-guided thrombectomy, foam sclerotherapy, and endovenous laser ablation. Chronic venous occlusion was observed to be fibrotic rather than thrombotic. CONCLUSIONS: Endoscopic imaging of the venous system has great potential to improve access and to guide endovenous interventions. Chronic venous occlusion in post-thrombotic syndrome is a fibrotic process, and chronic venous fibrosis is a better description of the type of occlusion and should replace chronic venous thrombosis.

Multilaboratory testing of thrombophilia: current and past practice in Australasia as assessed through the Royal College of Pathologists of Australasia Quality Assurance Program for Hematology.

We have conducted a series of multilaboratory surveys during the last 6 years to evaluate testing proficiency in the detection of congenital and acquired thrombophilia. For lupus anticoagulant (LA) testing, participant laboratories used a panel of tests, including activated partial thromboplastin time (aPTT; 100% of laboratories), kaolin clotting time (26 to 70%), and Russell's viper venom time (RVVT; 75 to 100%). Coefficients of variation (CVs) for assays ranged from 5 to 40%. RVVT assays appeared to be most sensitive and specific for detection of LA (fewer false-negatives or -positives), although laboratories performed best when they used a panel of tests. For congenital thrombophilia, tests evaluated comprised protein C (PC), protein S (PS), antithrombin (AT), and activated protein C resistance (APCR). Most participant laboratories performed PC using chromogenic (approximately 75%), or clot based (approximately 15%) assays, with few (< 10%) performing antigenic assessments. PS was most often assessed (approximately 60%) by immunological or antigenic assays, usually of free PS, or by functional or clot-based assays (approximately 40%). AT is usually assessed by functional chromogenic assays (approximately 95%). APCR was assessed using aPTT (approximately 50%) or RVVT (approximately 50%) clot-based assays, with the aPTT APCR typically performed using factor V-deficient plasma predilution, but the RVVT APCR typically performed without. Laboratories using the RVVT APCR generally performed better in detection of factor V Leiden-associated APCR, with the aPTT method group yielding higher false-negative and/or false-positive findings (approximately 5% of occasions). Some clot-based PC and PS assays appeared to be influenced by APCR status, and yielded lower apparent PC and PS levels with positive APC resistance. The overall error rate for PC, PS, and AT was approximately 2 to 8% (i.e., false-normal interpretations for deficient plasma or false-abnormal interpretations for normal plasma). The CVs for these assays ranged from 5 to 40%, with highest CVs typically obtained with PS assays.