Venclose RF Ablation System for the Treatment of IPVs: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Venclose RF Ablation System for the Treatment of IPVs (NCT04386785), a na na study. The primary outcome is Safety: AEs, SAEs, ADEs, SADEs, UADEs.

2. Clinical Question

3. Trial Design

This was a completed, investigator-initiated safety study of the Venclose RF Ablation System for treatment of incompetent perforator veins. The record describes it as a feasibility study in patients with refluxing perforator veins and lists chronic venous insufficiency as the condition. The intervention was endovascular thermal ablation in a single group. Enrollment is recorded as 27.

The design is listed as single-group, with allocation NA and no masking. There is no concurrent control arm, and the record does not describe random assignment. This matters because the study can describe events observed among treated participants, but it cannot estimate a treatment-versus-control difference from its own design. The record lists phase as NA.

The study start date is 2020-05-23, the primary completion date is 2021-04-13, and status is COMPLETED. These dates describe the registry timeline; they do not establish when each participant entered, completed follow-up, or contributed data. Participant-level timing and analysis-population details are not reported in the registry record.

The primary outcome is safety, expressed as events in the 3-day post-procedure timeframe. The description says procedure-related adverse events and device effects would be monitored and analyzed for acceptability after the study. The registry record lists 13 outcome measures, including labels related to acute ablation success and reflux, but does not give numerical results for those outcomes in the information recorded. It lists 0 analyses. The formal statistical analysis plan, eligibility criteria, and sample-size justification are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Safety: AEs, SAEs, ADEs, SADEs, UADEs, measured over 3-day post-procedure.

The primary endpoint is a safety assessment covering adverse events, serious adverse events, adverse device effects, serious adverse device effects, and unanticipated adverse device effects. Its unit is events, and its specified timeframe is 3-day post-procedure. The record describes monitoring procedure-related events and device effects for post-study assessment of acceptability.

Safety endpoints are used to characterize potential harms observed during and after a procedure. Event categories distinguish general adverse events from events considered serious or related to the device, although the registry description does not provide category definitions or attribution rules. Because the outcome is expressed as events, event counts and counts of affected participants are not automatically interchangeable: a participant may experience more than one event. The available registry summary does not provide enough detail to determine how recurrent events were handled in the primary outcome.

The short stated timeframe focuses the endpoint on immediate post-procedure safety. It does not, by itself, describe later safety experience. The record does not report a prespecified threshold for acceptability, a formal hypothesis test, or a numerical primary-endpoint result broken down by the named categories. The adverse-event summary does report affected-participant counts; those counts should be read as descriptive safety information rather than as a comparative estimate.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In general, a single-group study describes outcomes observed among participants who receive the intervention. It can report counts, proportions, or other summaries for that group if those results are available. It cannot, on its own, separate changes associated with treatment from changes that might have occurred over time, from other care, or from characteristics of the enrolled participants. A comparison requires a suitable reference group or another defensible design for estimating what would have happened without the intervention.

For this study, allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. There is no like-for-like control comparison. As a result, the registry's safety summary should be read descriptively. It does not produce a relative risk, risk difference, or comparative treatment estimate. Such estimates would require a comparison group and the relevant outcome data, neither of which is recorded for this study.

What does an event count tell the reader?

In general, an event count is the number of events recorded under a defined outcome and observation period. It is distinct from the number of participants who experienced an event. A participant can have multiple events, and an event may be counted under more than one category if the protocol's definitions allow that. For meaningful interpretation, readers need the event definitions, attribution rules, collection procedures, and handling of recurrent events.

The primary endpoint is specified in events, with a 3-day post-procedure timeframe. The adverse-event summary gives counts of affected participants in the serious, other, and death fields, rather than a detailed event-level breakdown. The registry record does not report how event-level data were summarized for the primary endpoint, whether multiple events per participant were counted separately, or how device relatedness was assessed. The participant counts therefore should not be treated as a complete event-count distribution.

Why do uncertainty intervals matter?

In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical model. Its width reflects statistical uncertainty as well as the amount and variability of information available. A narrow interval indicates greater precision under that model; a wide interval indicates less precision. A confidence interval is not a guarantee that the true value lies within its limits, and it does not correct for biased outcome collection or an unsuitable design.

The registry record does not report confidence intervals for the safety summaries. Without an interval or another uncertainty measure, the zero counts cannot be translated into a precise upper bound on risk from the information recorded. In particular, the count does not demonstrate that rare events cannot occur. The interpretation is also restricted by the stated short-term timeframe and by the absence of reported details about completeness of follow-up.

What would an inferential analysis require?

In general, an inferential analysis begins with a defined estimand: the outcome, population, treatment condition, comparison, and time point of interest. It then specifies the statistical model and how the analysis handles missing observations, repeated measurements, departures from distributional assumptions, and multiplicity. A reported estimate is most useful when accompanied by its uncertainty and a clear description of the analysis population.

The registry record lists 0 analyses and does not report a statistical analysis plan, analysis population, confidence intervals, or hypothesis-test results. The primary outcome description states that events would be monitored and analyzed for acceptability, but it does not specify a numerical acceptability threshold or inferential procedure. No particular model, adjustment, or missing-data method should be inferred from that wording.

General statistical concepts such as over-dispersion matter when counts vary more than a chosen count model expects; accounting for that variability can change uncertainty estimates. However, the record does not describe a count model or provide event-level data that would support evaluating over-dispersion. It would be inappropriate to claim that such a method was used or was necessary in this analysis.

How should planning calculations be read?

In general, a sample-size calculation is a prospective planning tool. It relates a target effect, outcome variability, significance criterion, allocation, and desired power to a planned amount of information. It is not a result from enrolled participants. Post hoc calculations sometimes use an observed effect, but those do not establish observed power or replace an estimate with an uncertainty interval.

The stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. That setup is not a description of this single-group trial. Any such illustration should be read only as a hypothetical planning scenario and not as the design actually used, as observed power, or as evidence of a treatment effect. The registry record does not report a trial-specific sample-size justification, and the effect size and planning outputs are not recorded in the registry entries.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures, with labels that include acute ablation success and reflux. It does not report a multiplicity strategy, such as a hierarchy of outcomes, an adjustment for multiple testing, or a rule for interpreting several tests together. Without those details and without reported outcome analyses, it is not possible to assess how multiplicity may have been handled. In general, testing many outcomes can increase the chance of apparently notable findings arising by chance; a prespecified plan helps readers distinguish confirmatory from exploratory analyses.

The record lists 0 analyses. Numerical results and inferential analyses for the secondary outcomes are not reported in the registry record. The record also does not report an analysis population, participant flow through follow-up, missing-data counts, reasons for missingness, or a method for handling missing observations. It is therefore not possible to determine whether all enrolled participants contributed to each outcome or whether the analysis used an intention-to-treat, per-protocol, or other population.

In general, missing data can affect interpretation when the likelihood of an observation being missing is related to a participant's health, experience, or outcome. Statistical approaches depend on the amount and pattern of missingness and on assumptions that should be stated. No particular missing-data mechanism or method can be inferred for this study. These omissions limit assessment of completeness and robustness; they do not establish that data were missing or that a particular bias occurred.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry's safety summary lists 27 at risk in the single treatment group. It records 0 participants affected by serious adverse events, 0 affected by other adverse events, and 0 deaths. These are the posted counts for the categories in the adverse summary; they are not a comparison against an untreated or alternative-treatment group.

Read the zero counts as no affected participants recorded in those summary categories, not as proof that the underlying risk is absent. The primary safety timeframe is 3-day post-procedure. The record does not report event-level totals, detailed definitions, completeness of follow-up, or category-specific confidence intervals. It also does not list specific serious event terms. Those omissions make it difficult to assess how comprehensively events were captured or how precisely the counts characterize risk.

The endpoint description includes several categories of adverse events and device effects, but the summary available for interpretation does not separately quantify every named category. Participant counts and event counts may differ when a participant experiences repeated events. The available figures should therefore be treated as short-term descriptive safety information, not as a complete account of all events or as evidence of comparative safety.

12. What the Result Does, and Does Not, Mean

The result that can be read from the registry is a short-term safety summary for a single group treated with endovascular thermal ablation. The adverse-event record lists 27 at risk and records 0 affected by serious adverse events, 0 affected by other adverse events, and 0 deaths. The study is marked completed, and its primary safety timeframe is 3-day post-procedure.

Those counts do not establish that treatment is safe or unsafe, and they do not estimate how the safety experience differs from another approach. There is no randomized or concurrent control group. The counts also do not establish that the risk of an event is zero: they describe what was recorded in this study summary and within its stated timeframe. Details needed to evaluate event ascertainment and follow-up completeness are not reported in the registry record.

The registry record does not provide numerical results for the listed acute ablation success or reflux outcomes, and it lists 0 analyses. It therefore does not support conclusions about the magnitude, precision, or statistical significance of changes in those outcomes. The existence of an outcome label is not itself evidence that the outcome improved, worsened, or remained unchanged.

In general, a feasibility study can provide descriptive information about whether a procedure and its outcome monitoring were undertaken in a clinical study. Its findings can inform questions for further research, but they are not a substitute for a controlled comparison when the question concerns relative effects. Here, the record does not report the protocol details, sample-size justification, or inferential plan needed to evaluate such questions.

Sample-size planning illustrations are prospective or hypothetical calculations, not observed power and not evidence of treatment effect. The stated illustration assumptions use equal allocation between two arms, whereas the recorded study has a single group. The illustrations therefore should not be interpreted as a description of the actual trial design. The appropriate conclusion is limited: the registry records the stated short-term safety counts, while comparative efficacy and broader or longer-term safety remain unestablished by the information recorded.

13. Why This Trial Matters Statistically

This study is statistically notable for the gap between its safety objective and the information available for estimating uncertainty. A registry can identify the outcome categories and observation timeframe, and it can report observed counts. For interpretation, however, readers also need detailed outcome definitions, event-level summaries, the analysis population, and uncertainty measures. Those details are not reported in the registry record.

The single-group design is central to what can be learned. It allows the record to describe observations after the intervention, but it does not provide a concurrent control against which to interpret those observations. Even a complete count of events would not by itself isolate the effect of the device from other explanations. This distinction is important whenever descriptive safety data are discussed alongside claims about comparative effects.

The record lists 13 outcome measures and 0 analyses. The absence of reported numerical results for the secondary outcomes makes it impossible to assess their size or precision and leaves multiplicity handling unclear. A prespecified analysis strategy and transparent reporting of estimates and uncertainty would help readers understand which questions the study could address and how strongly the data support each answer.

The planning assumptions also illustrate why design context matters. The stated planning calculation assumes equal allocation between two arms, while the actual record describes a single group. A hypothetical calculation under those assumptions cannot be treated as a description of this study or as observed power. Clear separation of planning scenarios from analyses of enrolled participants helps prevent readers from mistaking a design illustration for evidence.

In general, these issues do not invalidate descriptive counts. They define their scope. The study's recorded safety summary can be read as a report of observed short-term categories, while the design and reporting gaps limit precision, comparability, and conclusions about outcomes not numerically reported.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The single-group design has no concurrent comparator, so it cannot estimate a treatment-versus-control difference. Allocation is listed as NA and masking as NONE. This limits causal interpretation and may leave outcome assessment open to expectation or classification effects, although the registry record does not describe whether those effects occurred.

The stated primary safety timeframe is 3-day post-procedure. The record does not report longer-term safety results or numerical results for the listed acute ablation success and reflux outcomes. Its adverse summary provides affected-participant counts, but the primary endpoint is expressed in events; event-level totals and the handling of repeated events are not reported in the registry record.

Important design and analysis details are also absent. Eligibility criteria, baseline participant characteristics, follow-up completeness, missing-data handling, outcome definitions, device-relatedness rules, the statistical analysis plan, and a trial-specific sample-size justification are not reported in the registry record. The record lists 0 analyses, so there are no reported estimates or uncertainty intervals for assessing precision. These reporting gaps make it difficult to judge representativeness, completeness, and the robustness of the recorded counts.

The study is described as a feasibility and safety study, and its enrollment is 27. The registry summary should not be used to infer a rate beyond the recorded categories and timeframe. A zero count does not show that rare outcomes are impossible, and no conclusion about comparative effectiveness or safety follows from these data alone. The stated sample-size planning assumptions describe a hypothetical two-arm illustration rather than the single-group study design.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Venclose RF Ablation System for the Treatment of IPVs — NCT04386785.
• Registry record last updated 2022-05-27; status last verified 2022-05.
• Results first posted 2022-05-27.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes NCT04386785, titled Venclose RF Ablation System for the Treatment of IPVs. It is a completed, investigator-initiated, single-group feasibility and safety study of radiofrequency thermal ablation for incompetent perforator veins in patients with chronic venous insufficiency. Enrollment is recorded as 27. Allocation is NA, masking is NONE, and phase is NA.

The primary outcome concerns adverse events and device effects during the 3-day post-procedure timeframe. The adverse summary records 27 at risk, 0 affected by serious adverse events, 0 affected by other adverse events, and 0 deaths. The registry lists 13 outcome measures and 0 analyses. Numerical results for the listed secondary outcomes, inferential analyses, and a formal statistical plan are not reported in the registry record. With no control group, the recorded safety counts are descriptive and do not establish comparative effects.