Nonthermal Endovenous Procedures for Varicose Veins: A Health Technology Assessment.
Bibliographic record
Abstract
BACKGROUND: Varicose veins are part of the spectrum of chronic venous disease and are a sign of underlying chronic venous insufficiency. Treatments to address varicose veins include surgical vein removal under general anesthesia, or endovenous laser (EVLA) or radiofrequency ablation (RFA) under tumescent anesthesia. Two newer nonthermal endovenous procedures can close veins without any tumescent anesthesia, using either mechanochemical ablation (MOCA, a combination of mechanical and chemical techniques) or cyanoacrylate adhesive closure (CAC). We conducted a health technology assessment of these nonthermal endovenous procedures for people with symptomatic varicose veins, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding MOCA and CAC, and patient preferences and values. METHODS: We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane Risk of Bias or RoBANS tool, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Meta-analysis was conducted using Review Manager 5.2, where appropriate.We performed a systematic economic literature search and conducted a cost-utility analysis with a 5-year time horizon from the perspective of Ontario Ministry of Health. In our primary economic evaluation, we assessed the cost-effectiveness of nonthermal endovenous procedures (CAC and MOCA) compared with surgical vein stripping and thermal endovenous therapies (EVLA and RFA). We also analyzed the budget impact of publicly funding nonthermal and thermal endovenous therapies for adults with symptomatic varicose veins in Ontario over the next 5 years. Costs are expressed in 2020 Canadian dollars.To contextualize the potential value of nonthermal endovenous treatments, we spoke with 13 people with varicose veins who had sought various treatment options. We conducted phone interviews and qualitatively analyzed their responses regarding their care journey and the impact of different treatment options; the only nonthermal treatment that participants had experience with was CAC. RESULTS: We included 19 primary studies reported in 25 publications comparing either MOCA or CAC with at least one other invasive treatment for symptomatic varicose veins. No studies compared MOCA with CAC. Based on evidence of low to moderate quality, MOCA resulted in slightly poorer technical outcomes (vein closure and recanalization) than thermal endovenous ablation procedures. However, clinical outcomes, quality of life improvement, and patient satisfaction were similar compared with RFA (GRADE: Very low to Moderate) and EVLA (GRADE: High). Cyanoacrylate adhesive closure resulted in little to no difference in technical outcomes, clinical outcomes, and quality of life improvement compared with RFA and EVLA (GRADE: Moderate). Patient satisfaction may also be similar (GRADE: Low). Recovery time was slightly reduced with nonthermal endovenous procedures compared with thermal ablation (GRADE: Moderate). The effect of CAC compared with surgical vein stripping is very uncertain (GRADE: Very low). Major complications of any procedure were rare, with minor complications occurring as expected and resolving.We included two European studies in the economic evidence review that were partially applicable to the Ontario context. Both studies found that thermal ablation procedures (RFA, EVLA, or steam vein sclerosis) were the most cost-effective treatments, compared with surgical vein stripping and nonthermal therapies. Our cost-utility analysis showed that surgical vein stripping is the least effective and most costly treatment among five treatments for varicose veins. Differences in quality-adjusted life-years (QALYs) between endovenous treatments (CAC, MOCA, RFA, and EVLA) were small. When the willingness-to-pay (WTP) value was $50,000 per QALY gained, the probabilities of being cost-effective were 55.6%, 18.8%, 15.6%, 10.0%, and 0%, for EVLA, CAC, MOCA, RFA, and surgical vein stripping, respectively. When the WTP was $100,000 per QALY gained, the probabilities of being cost-effective were 40.2%, 30.0%, 17.7%, 12.1%, and 0%, for EVLA, CAC, RFA, MOCA, and surgical vein stripping, respectively. Publicly funding endovenous procedures (both nonthermal and thermal) would increase the total volume of treatments, resulting in a total 5-year budget impact of around $17 million.People with varicose veins with whom we spoke reported positively on their experiences with the CAC procedure and its outcomes. They also described geographic and financial barriers to accessing the range of available treatment options. CONCLUSIONS: Cyanoacrylate adhesive closure and MOCA produced similar patient-important outcomes, and slightly shorter recovery compared with thermal ablation. Cyanoacrylate adhesive closure yielded similar anatomical outcomes as thermal endovenous ablation, but the technical outcomes of MOCA were slightly poorer.Compared with surgical vein stripping, all endovenous treatments were more effective and less expensive. If we were to look at the most cost-effective strategy (at WTP less than $100,000 per QALY), EVLA is most likely to be cost-effective. Assuming an 80% increase in the number of eligible people over the next 5 years, we estimate that publicly funding nonthermal and thermal endovenous treatments for varicose veins in Ontario would range from $2.59 million in year 1 to $4.35 million in year 5, and that the total 5-year budget impact would be around $17 million.For people with varicose veins, the CAC procedure was seen as a positive treatment method that reduced their symptoms and improved their quality of life.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.053 | 0.164 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.009 | 0.018 |
| Bibliometrics | 0.031 | 0.022 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.006 | 0.004 |
| Open science | 0.002 | 0.004 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".