Endovenous thermal ablation in the treatment of large great saphenous veins of diameters > 12 mm: A systematic review meta-analysis and meta-regression

BACKGROUND

We sought to assess the safety and efficacy of endovenous thermal ablation (EVTA) in treating large great saphenous veins (GSV) > 12 mm in diameter.

METHODS

We performed a systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 for comparative and noncomparative studies depicting EVTA in the treatment of GSV > 12 mm. Primary endpoints included GSV occlusion, technical success, deep vein thrombosis (DVT), and endovenous heat-induced thrombosis (EHIT). We conducted a comparative analysis between GSV > 12 mm and < 12 mm and a meta-regression analysis for two sets of studies, one including the whole dataset, containing treatment arms of comparative studies with GSV < 12 mm and one exclusively for GSV > 12 mm.

RESULTS

Seven studies, including 2564 GSV, depicting radiofrequency (RFA) and endovenous laser ablation (EVLA) were included. GSV > 12 mm occlusion, technical success, DVT, and EHIT estimates were 95.9% (95% CI: 93.6-97.8), 99.9% (95% CI: 98.9-100.0), 0.04% (95% CI: 0.0-3.4), and 1.6% (95% CI: 0.3-3.5). Meta-regression revealed a negative association between GSV diameter and occlusion for both the whole dataset (p < 0.01) and the > 12 mm groups (p = 0.04), GSV diameter and technical success for both groups (p < 0.01), (p = 0.016), and GSV diameter and EHIT only for the whole dataset (p = 0.02). The comparative analysis between GSV < 12 mm and GSV > 12 mm displayed an occlusion estimate of OR 1.79 (95% CI: 1.25-2.56) favoring small GSV.

CONCLUSION

Whereas we have displayed excellent occlusion and technical success results for the EVTA of GSV > 12 mm, our analysis has illustrated the unfavorable impact of GSV diameter on occlusion, technical success, and EHIT outcomes regardless of the 12 mm threshold. Potential parameter or device adjustments in a diameter-oriented fashion could further enhance outcomes.

Thrombus extension after cyanoacrylate closure of incompetent saphenous veins

BACKGROUND

Cyanoacrylate closure (CAC) is a minimally invasive surgery to treat incompetent saphenous veins. This study aimed to investigate the incidence, the risk factors for, and the management of thrombus extension after cyanoacrylate closure (TEACAC) of incompetent saphenous veins in patients with chronic venous disease.

METHODS

This retrospective study included patients aged >18 years who were diagnosed with chronic venous disease with superficial venous reflux in the great saphenous vein, anterior accessory saphenous vein, or small saphenous vein, and who were treated with CAC at Siriraj Hospital (Bangkok, Thailand) during January 2017 to December 2018.

RESULTS

A total of 126 saphenous veins of 101 patients were included. TEACAC occurred in 5 of 101 (4.9%) patients, and in 5 of 126 (3.9%) treated saphenous veins. The mean follow-up time was 285±12 days. Based on Kabnick classification of endovenous heat-induced thrombosis (EHIT), the following TEACAC grades were observed: grade I (n=2), grade II (n=1), grade III (n=2), and grade IV (n=0). No patient or procedural predictive factors for TEACAC were identified. In patients with TEACAC-1 or TEACAC-2, the thrombus spontaneously disappeared by the 2-week follow-up. Patients with TEACAC-3 received therapeutic rivaroxaban or dabigatran, which resolved the thrombus within 2-4 weeks. No deep vein thrombosis or symptomatic pulmonary embolism was found.

CONCLUSIONS

TEACAC was found not to be a rare complication after CAC. All patients should be informed of the risk of TEACAC prior to treatment. Treatment of TEACAC class 1-3 following EHIT guideline seems to be both safe and effective.

Endothermal Heat Induced Thrombosis

Endothermal heat induced thrombosis (EHIT) is a post-procedural entity following endothermal superficial venous ablation that refers to the propagation of thrombus into the adjacent deep vein lumen. It is identified most commonly during the post-procedural surveillance venous duplex ultrasound. EHIT is recognized as a unique post-procedural entity, distinct in clinical behavior from a deep vein thrombosis. The definition, classification systems, pathophysiology, risk factors, treatment, and prevention are all discussed. The understanding of EHIT has advanced considerably, but additional data are required to understand its impact on quality of life and the cost-effectiveness of surveillance.

Current status of endothermal heat induced thrombosis

BACKGROUND

There remain many questions regarding the pathophysiology and risk factors for endothermal heat induced thrombosis formation. Moreover, there are a paucity of data on the timing of its occurrence, and there has been no consensus regarding for its treatment. The purpose of this review is to summarize the current knowledge on the pathophysiology, risk factors and treatment strategies for endothermal heat induced thrombosis.

METHODS

The PubMed database was searched from 2001 to present for endothermal heat induced thrombosis, EHIT, deep vein thrombosis, chronic venous insufficiency, varicose veins, endovenous laser and radiofrequency ablation (treatment). All relevant articles identified by the authors mentioning endothermal heat induced thrombosis were included in this review.

RESULTS

A multitude of risk factors, several pathophysiological hypotheses and different treatment strategies are described in the literature.

CONCLUSIONS

Endothermal heat induced thrombosis is marginally understood. There remains a theoretical risk for significant venous thromboembolic complications. With the new uniform classification of EHIT (American Venous Forum), healthcare providers should continue to investigate the nature of this event.

Classification and treatment of endothermal heat-induced thrombosis: Recommendations from the American Venous Forum and the Society for Vascular Surgery

The American Venous Forum (AVF) and the Society for Vascular Surgery set forth these guidelines for the management of endothermal heat-induced thrombosis (EHIT). The guidelines serve to compile the body of literature on EHIT and to put forth evidence-based recommendations. The guidelines are divided into the following categories: classification of EHIT, risk factors and prevention, and treatment of EHIT. One major feature is to standardize the reporting under one classification system. The Kabnick and Lawrence classification systems are now combined into the AVF EHIT classification system. The novel classification system affords standardization in reporting but also allows continued combined evaluation with the current body of literature. Recommendations codify the use of duplex ultrasound for the diagnosis of EHIT. Risk factor assessments and methods of prevention including mechanical prophylaxis, chemical prophylaxis, and ablation distance are discussed. Treatment guidelines are tailored to the AVF EHIT class (ie, I, II, III, IV). Reference is made to the use of surveillance, antiplatelet therapy, and anticoagulants as deemed indicated, and the recommendations incorporate the use of the novel direct oral anticoagulants. Last, EHIT management as it relates to the great and small saphenous veins is discussed.

Classification and treatment of endothermal heat-induced thrombosis: Recommendations from the American Venous Forum and the Society for Vascular Surgery This Practice Guidelines document has been co-published in Phlebology [DOI: 10.1177/0268355520953759] and Journal of Vascular Surgery: Venous and Lymphatic Disorders [DOI: 10.1016/j.jvsv.2020.06.008]. The publications are identical except for minor stylistic and spelling differences in keeping with each journal's style. The contribution has been published under a Attribution-Non Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0), (https://creativecommons.org/licenses/by-nc-nd/4.0/)

The American Venous Forum (AVF) and the Society for Vascular Surgery set forth these guidelines for the management of endothermal heat-induced thrombosis (EHIT). The guidelines serve to compile the body of literature on EHIT and to put forth evidence-based recommendations. The guidelines are divided into the following categories: classification of EHIT, risk factors and prevention, and treatment of EHIT.

One major feature is to standardize the reporting under one classification system. The Kabnick and Lawrence classification systems are now combined into the AVF EHIT classification system. The novel classification system affords standardization in reporting but also allows continued combined evaluation with the current body of literature. Recommendations codify the use of duplex ultrasound for the diagnosis of EHIT. Risk factor assessments and methods of prevention including mechanical prophylaxis, chemical prophylaxis, and ablation distance are discussed.

Treatment guidelines are tailored to the AVF EHIT class (ie, I, II, III, IV). Reference is made to the use of surveillance, antiplatelet therapy, and anticoagulants as deemed indicated, and the recommendations incorporate the use of the novel direct oral anticoagulants. Last, EHIT management as it relates to the great and small saphenous veins is discussed.

Determining Risk Factors for Endovenous Heat-induced Thrombosis after Radiofrequency Ablation

BACKGROUND

The objective of this study was to evaluate risk factors, incidence, management, and outcome of endovenous heat-induced thrombosis (EHIT) related to radiofrequency ablation (RFA).

METHODS

This was a single-center retrospective analysis of patients over the age of 18 who underwent RFA between 2016 and 2019. Demographics, comorbidities, medications, severity scores, vascular anatomy, procedural details, and outcome data were collected. EHIT-related data included occurrence, grade, laterality, management, and outcome.

RESULTS

During the study period, 672 RFA procedures were performed at our institution. Of these, 642 (median age 57 (21-93), 62.3% female) met study inclusion criteria. EHIT was observed in 43 (6.6%) cases. Concurrent left common femoral vein (CFV) or right femoral vein (FV) incompetence was found to be more prevalent in the EHIT group (P = 0.024 and P = 0.011, respectively). Compared with performing RFA alone, concurrent performance of stab phlebectomy and sclerotherapy with RFA on the left side was found to be associated with possible increased risk for EHIT (P = 0.021). Furthermore, patients with diabetes mellitus (DM) (P = 0.05) and those with median diameter of the treated left vein of 1.2 cm (P = 0.02) were more likely to have a higher EHIT grade (III and IV) than those without DM and those with smaller vein diameter, respectively. Management included aspirin (44%), anticoagulant (28%), both (10%), or neither (18%). EHIT either resolved or regressed (64%), did not change (5%), or propagated (8%) at follow-up.

CONCLUSIONS

Left CFV or right FV incompetence was found to be more prevalent in the total EHIT group. Furthermore, DM and the median size of the treated vein on the left (1.2 cm) were more prevalent in the high (III-IV) versus low grade (I-II) EHIT group. More than 50% of EHIT improved (regressed or resolved) at follow-up regardless of the management option. Further analysis with larger patient samples are needed to confirm the association between these variables and the development of EHIT.