Understanding Venous Remodeling After Minimally Invasive and Noninvasive Treatments for Varicose Veins: A Mechanistic Narrative Review

The absence of detectable flow on duplex ultrasound after venous ablation may correspond to different tissue states. This mechanistic narrative review examines histopathological and immunohistochemical responses after thermal, chemical, mechanochemical, adhesive, and focused ultrasound treatments. The PubMed search, conducted on 6 September 2026 for publications available through 31 August 2026, resulted in the inclusion of 45 tissue-based publications; six additional references provided clinical context. Study selection and data extraction were performed by a single author. Human and experimental data were organized by wall compartment, treatment modality, and time point. Depending on the technique, the initial signatures comprised thermal injury, endothelial detergent toxicity, mechanical abrasion, adhesive polymerization, or cavitation. Luminal organization, fibrosis, and recanalization followed heterogeneous trajectories. Cyanoacrylate was distinguished by a biomaterial response with variable persistence. Early occlusion does not demonstrate mature fibrous obliteration. The depth–continuity–topography framework is a working hypothesis without validated predictive value. Combining longitudinal duplex ultrasound follow-up with end-point histological analysis of the same segment, including morphometry, immunohistochemistry, and matrix assessment, could better relate tissue status to clinical outcome.