A two-cohort feasibility study on polyglycolic acid yarn implantation for abolition of saphenous vein reflux.

OBJECTIVE: The objective of this study was to evaluate the feasibility and safety of a polyglycolic acid (PGA) yarn implant for nonthermal ablation of saphenous vein reflux. METHODS: In two consecutive cohort studies (TAHOE I and TAHOE II), the feasibility of abolition of great saphenous vein (GSV) reflux by implantation of a PGA yarn was tested under ultrasound guidance in 51 and 30 patients, respectively. The use of tumescent local anesthesia was not required. Graduated compression stockings and thrombosis prophylaxis with low-molecular-weight heparin were used for 2 weeks after intervention in the first study only. RESULTS: Of 81 enrolled patients, 77 (95%) were available at 6-month follow-up. Complete occlusion of the treated GSV was confirmed by duplex ultrasound in all patients except one patient at day 1. In TAHOE II, closure was preserved in a higher percentage of patients at 6 weeks, with 96.4% vs 82.0% in TAHOE I. The 6-month Kaplan-Meier estimated occlusion rates for TAHOE I and TAHOE II were 68% (95% confidence interval [CI], 54%-79%) and 69% (95% CI, 49%-82%), respectively, with an estimated combined occlusion rate of 69% (95% CI, 57%-76%). Kaplan-Meier analysis yielded a combined reflux-free rate of 85% (95% CI, 75%-91%) at 3 months of follow-up and a rate of 81% (95% CI, 71%-88%) at 6 months of follow-up. Venous Clinical Severity Score (VCSS) improved from a combined mean of 4.6 ± 3.1 at baseline to 2.1 ± 2.2 and 1.6 ± 1.9 at 3 and 6 months, respectively (P < .0001 for 3- and 6-month results). In TAHOE II, four patients with venous ulcers healed at an average of 1.3 months after treatment. CONCLUSIONS: First-in-human use of an endovenous PGA yarn implant for occlusion of refluxing GSVs proved to be feasible, with no serious adverse events. However, recanalization was observed during a period of 6 months in 31% of patients.

Innate Effector-Memory T-Cell Activation Regulates Post-Thrombotic Vein Wall Inflammation and Thrombus Resolution.

RATIONALE: Immune cells play an important role during the generation and resolution of thrombosis. T cells are powerful regulators of immune and nonimmune cell function, however, their role in sterile inflammation in venous thrombosis has not been systematically examined. OBJECTIVE: This study investigated the recruitment, activation, and inflammatory activity of T cells in deep vein thrombosis and its consequences for venous thrombus resolution. METHODS AND RESULTS: CD4+ and CD8+ T cells infiltrate the thrombus and vein wall rapidly on deep vein thrombosis induction and remain in the tissue throughout the thrombus resolution. In the vein wall, recruited T cells largely consist of effector-memory T (TEM) cells. Using T-cell receptor transgenic reporter mice, we demonstrate that deep vein thrombosis-recruited TEM receive an immediate antigen-independent activation and produce IFN-γ (interferon) in situ. Mapping inflammatory conditions in the thrombotic vein, we identify a set of deep vein thrombosis upregulated cytokines and chemokines that synergize to induce antigen-independent IFN-γ production in CD4+ and CD8+ TEM cells. Reducing the number of TEM cells through a depletion recovery procedure, we show that intravenous TEM activation determines neutrophil and monocyte recruitment and delays thrombus neovascularization and resolution. Examining T-cell recruitment in human venous stasis, we show that superficial varicose veins preferentially contain activated memory T cells. CONCLUSIONS: TEM orchestrate the inflammatory response in venous thrombosis affecting thrombus resolution.