CTAG Dissection/Trauma Post Marketing Surveillance Japan: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for CTAG Dissection/Trauma Post Marketing Surveillance Japan (NCT05414318), a registered phase not stated study. The primary outcome is Major Device-related Adverse Events.

2. Clinical Question

3. Trial Design

This is a completed post-marketing surveillance study in Japan of the Conformable GORE® TAG® Thoracic Endoprosthesis. The registry lists W.L.Gore & Associates as sponsor, enrollment of 55, a study start date of 2016-01-05, and a primary completion date of 2022-12-23. The listed conditions are thoracic aortic aneurysm, thoracic aorta injury, and thoracic aortic dissection. The study status is completed.

The registry identifies one device intervention and separates the adverse-event summaries into dissection and trauma groups. There are 43 participants at risk in the dissection group and 12 in the trauma group. These are clinical categories, not treatment arms in a randomized comparison. Allocation is not stated. Accordingly, the group summaries are descriptive and do not constitute evidence from a controlled head-to-head comparison.

The primary outcome is described as the number of participants with major device-related adverse events, over the period from the procedure through 5 years. The registry writes the timeframe as “Day 0-2006”; that wording is retained without interpretation. Although the record identifies 9 outcome measures, it lists 0 analyses. The primary outcome count and an inferential analysis are not reported in the registry record.

The registry does not report a protocol sample-size justification, a detailed analysis plan, randomization procedures, or a comparator group. It also does not explain how participants were followed, how outcome events were adjudicated, or how missing observations were handled. These omissions limit what can be concluded about study conduct and how fully the surveillance findings can be interpreted.

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

Analysis population for the primary outcome, as defined in the registry: Patients with acute complicated Stanford type B dissection with evaluable result. (Not a protocol-defined endpoint for trauma arm and therefore not evaluated)

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 Major Device-related Adverse Events, measured over Procedure through 5 years (Day 0-2006).

The primary endpoint is the number of participants with major device-related adverse events. It is a binary participant-level outcome: each person is classified according to whether they experienced at least one qualifying event during the stated observation period. The registry gives the period as procedure through 5 years and writes the timeframe “Day 0-2006.” No primary endpoint result is reported in the registry record.

Counting participants rather than counting every event can be useful when the question is how many people experienced a serious or otherwise important complication. A participant with repeated events is counted once for this kind of measure, whereas an event-count endpoint could count each occurrence. This distinction matters because the resulting numbers describe different things. The registry’s description specifies participants, not recurrent-event totals.

The device-related attribution is also part of the endpoint definition: the primary outcome concerns major events considered related to the device. That is distinct from a summary of all serious adverse events, which may include events that are not device-related. The registry does not report the operational definition of “major,” the process used to judge device relatedness, or the primary endpoint count. The endpoint’s stated purpose can therefore be described, but its observed frequency and the precision of that estimate cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is a participant count: the number of people with at least one qualifying major device-related adverse event during the stated period. General statistical explanation: a binary outcome records whether an event occurred for each participant, rather than how many times it occurred. A count of affected participants and a count of all event episodes answer different questions. The registry describes the primary endpoint as a participant count but does not report its observed value.

What does a participant count represent?

For a binary endpoint, the underlying information is whether each participant met the outcome definition. A summary may report the number meeting that definition, and sometimes the number assessed. The registry’s primary endpoint description supplies the outcome type and observation period, but not the observed count or the number with complete primary endpoint assessment. The adverse-event summaries do report participants at risk and participants affected for the serious and other adverse-event categories. Those summaries should not be treated as the missing primary endpoint result because their event definitions differ in the record.

General statistical explanation: uncertainty around a binary event frequency can be described with a confidence interval. Such an interval conveys the range of values reasonably compatible with the observed data under the method used; it is not a guarantee that the true value lies within the interval. The registry record does not report a confidence interval or the primary outcome count, so the precision of the primary endpoint cannot be assessed.

Why does study design matter?

The record describes post-marketing surveillance and separates summaries by dissection and trauma. It does not describe random allocation or a control group; allocation is not stated. General statistical explanation: randomization can help balance measured and unmeasured participant characteristics between treatment groups, while a nonrandomized comparison can be affected by differences in who receives each treatment or belongs to each group. Here, the listed clinical categories are not presented as treatment arms. Their counts can describe the surveillance summaries, but they do not estimate a comparative effect of the device.

The record does not state whether analyses adjusted for participant characteristics, differences in follow-up, or other factors. No model or adjusted estimate is listed. It is therefore not possible to determine from the registry whether any statistical control for such factors was planned or used.

How should safety categories be distinguished?

The primary endpoint is specific to major events considered device-related. Serious adverse events are a broader safety summary in the registry and are not automatically device-related. The list of serious-event terms includes “Other Complications (not device complication),” underscoring that a serious event can be recorded without being classified as a device complication. The record does not describe the event adjudication process or the criteria for severity and device attribution. These definitions affect which events enter each category and how counts should be understood.

The reported term percentages are 8.3%, 7.0%, 7.0%, 4.7%, 4.7%, and 4.7% for the listed terms. Their denominator and counting rules are not reported in the registry record. Without that information, the percentages cannot be independently interpreted as participant-level risks or event-level proportions. General statistical explanation: a percentage’s meaning depends on what forms its numerator and denominator; the same percentage can describe different quantities under different counting rules.

What do the planning assumptions mean?

The registry’s sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The planning illustration is not the trial’s own sample-size justification. Its detectable effect is described as a stated fraction of the observed effect. The assumptions do not establish that this surveillance study randomized participants or had two comparable arms; the registry specifically lacks a like-for-like control comparison.

Any sample-size values calculated under those assumptions are planning illustrations, not observed power and not evidence that the study had a particular probability of detecting an effect. General statistical explanation: power calculations depend on assumptions about the outcome, effect size, allocation, and analysis. Changing those assumptions changes the planning result. The registry does not report a protocol sample-size justification or explain how the illustration relates to the surveillance design.

Overall, the available methods information is limited. The registry identifies the endpoint type, event period, clinical categories, and planning assumptions, but it does not report a primary endpoint analysis, confidence intervals, a statistical model, an analysis population, or the missing-data approach. These gaps prevent an assessment of the planned inferential methods and the uncertainty around the primary outcome.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Dissection", "Trauma")
n      <- c(43, 12)
events <- c(3, 0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Dissection  43  3  7.0  1.5  19.1  2.4  18.6  2.5  18.7
ARM  Trauma  12  0  0.0  0.0  26.5  0.0  24.2  0.2  24.7

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies 9 outcome measures and 0 analyses. It does not report a multiplicity strategy, such as a prespecified approach to interpreting multiple outcome tests. Because no analyses are listed, there are no reported primary or secondary hypothesis tests to interpret, and no adjustment procedure is reported in the registry record. The existence of multiple outcome measures alone does not establish that inferential tests were conducted.

The record identifies the primary outcome as major device-related adverse events but does not report its observed count. It also does not report a confidence interval, p-value, or analysis population for that endpoint. No statistical plan is listed that would clarify whether the endpoint was analyzed as prespecified or how any additional outcomes were treated.

Missing-data methods are not reported in the registry record. The available summaries give participants at risk and affected for the adverse-event categories, but they do not explain whether participants without complete follow-up were excluded, how incomplete observation was handled, or whether outcome status was known for everyone over the stated timeframe. The record does not report the completeness of follow-up or the number of participants with missing endpoint information.

Analysis-population definitions are also not reported. The registry does not state which participants were included in each analysis or whether any exclusions occurred. Without these details, the reported safety counts can be described as recorded, but the completeness and representativeness of the underlying observations cannot be fully evaluated. These are reporting gaps; they do not establish that a particular multiplicity or missing-data method was omitted from the study’s conduct.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: other complications (not device complication) (8.3%), congestive heart failure (7.0%), bowel ischemia (7.0%), aortic rupture (4.7%), new aortic dissection (4.7%).

The safety summaries distinguish serious adverse events from other adverse events and report participants at risk and affected. In the dissection group, the serious-event figures are 43 at risk and 17 affected, while the other-event figures are 43 at risk and 0 affected. In the trauma group, the corresponding serious-event figures are 12 at risk and 1 affected, and the other-event figures are 12 at risk and 0 affected. Deaths are reported as 10 in dissection and 1 in trauma.

These are descriptive group counts. The registry does not establish that every serious event or death was caused by the device, and the serious-event figures are not identified as the primary endpoint count. The primary endpoint is specifically major device-related adverse events, for which no result is reported. The listed serious-event terms include events explicitly categorized as not device complications, so seriousness and device relatedness should not be treated as interchangeable.

The term percentages are reported as 8.3%, 7.0%, 7.0%, 4.7%, 4.7%, and 4.7%. Their denominators and counting rules are not reported in the registry record. They therefore should not be read as participant-level risks without further definition. The dissection and trauma groups are not randomized comparator arms, so their safety counts do not establish a comparative risk difference or causal effect.

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

The results that can be described are the registry’s safety counts and listed adverse-event terms, along with the study’s post-marketing surveillance design. The dissection and trauma groups have separately reported counts for participants at risk and affected by serious and other adverse events, as well as deaths. The record also lists serious adverse-event terms with percentages. These observations are descriptive summaries of the registry record.

The record does not report the primary endpoint result: the number of participants with major device-related adverse events over the stated period. It also does not report an analysis, confidence interval, or other estimate of uncertainty for that endpoint. Thus, the primary clinical question is stated, but its observed result cannot be evaluated from the recorded information.

The counts do not demonstrate that the device caused an event, prevented an event, or changed the likelihood of an outcome. Serious adverse events and deaths are not automatically device-related, and the registry does not give the adjudication details needed to assess attribution. The explicit term “Other Complications (not device complication)” illustrates why event seriousness alone is not enough to infer device causation.

Nor do the dissection and trauma summaries provide a treatment comparison. They are different clinical categories, not randomized arms; allocation is not stated, and a like-for-like control comparison is not available. Their counts should not be used to claim that one category has a higher or lower treatment-related risk than the other.

General statistical explanation: a result is most informative when the outcome definition, denominator, analysis population, follow-up, and uncertainty are clear. Several of those details are not reported in the registry record. The responsible interpretation is therefore limited to describing the available counts and noting the missing endpoint result and analysis, rather than drawing a conclusion about efficacy or comparative safety.

14. Why This Trial Matters Statistically

Post-marketing surveillance can contribute information about safety events recorded during use of a device outside a randomized trial. This record is statistically useful as a description of the monitoring question, the clinical categories used for the summaries, and the event counts that are reported. It identifies a primary endpoint focused on major device-related adverse events and specifies a follow-up period from the procedure through 5 years, written as “Day 0-2006.”

The record also illustrates why outcome definitions matter. The primary endpoint concerns device-related events, while the serious adverse-event summaries include broader categories. The listed terms include an event explicitly labeled not a device complication. Separating seriousness from causation is essential for reading safety data accurately, especially when the registry does not describe event adjudication criteria.

Statistically, the registry is informative about reporting limits as well as recorded counts. It has 9 outcome measures but lists 0 analyses, and the primary endpoint count is not reported. The term percentages lack reported denominators and counting rules. These gaps prevent readers from assessing uncertainty, comparing outcomes on a common basis, or determining how much follow-up contributed to each summary.

The study should not be mistaken for a randomized comparison. The dissection and trauma groups are distinct clinical categories, and allocation is not stated. Their summaries can be read as surveillance descriptions, not as evidence that the device performs differently across groups or compared with an alternative. This distinction is broadly important: descriptive safety data may be useful while remaining insufficient for causal or comparative conclusions.

15. 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 primary limitation for interpreting the central question is that the registry record does not report the observed count for major device-related adverse events. Although that outcome and its timeframe are identified, no corresponding analysis is listed. Consequently, neither the endpoint frequency nor its statistical precision can be assessed.

The record does not define “major” in detail or explain how device relatedness was judged. It does not report event-adjudication procedures, outcome assessment methods, or the criteria used to distinguish serious events from other events. These details matter because different definitions can change which observations are included in each safety category.

The safety summaries are separated into dissection and trauma groups, but these are not like-for-like control groups. Allocation is not stated, and there is no randomized comparison identified. Group counts therefore cannot support causal or comparative conclusions. The registry does not report participant characteristics that might help readers understand differences between the categories.

The denominators and counting rules for the listed serious-event percentages are not reported. The record also does not describe follow-up completeness, missing-data handling, or analysis-population definitions. Although the primary timeframe is stated as procedure through 5 years, the registry writes it as “Day 0-2006,” and no clarification of that wording is reported. These omissions limit assessment of the duration and completeness of observation.

Finally, the registry identifies 9 outcome measures but lists 0 analyses. It does not report a statistical analysis plan, confidence intervals, hypothesis tests, or adjustment methods. The sample-size assumptions are described as a planning illustration, not as the study’s own design justification. Together, these reporting limits mean the available information supports description of recorded safety summaries, but not a comprehensive evaluation of endpoint results or comparative effects.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: CTAG Dissection/Trauma Post Marketing Surveillance Japan — NCT05414318.
• Registry record last updated 2024-10-03; status last verified 2024-06.
• Results first posted 2024-10-03.
• 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.

19. Record Summary

The registry describes a completed post-marketing surveillance study in Japan of the Conformable GORE® TAG® Thoracic Endoprosthesis, sponsored by W.L.Gore & Associates. Enrollment is 55. The study start date is 2016-01-05, and the primary completion date is 2022-12-23. Listed conditions are thoracic aortic aneurysm, thoracic aorta injury, and thoracic aortic dissection.

The primary endpoint is the number of participants with major device-related adverse events from the procedure through 5 years, with the timeframe written as “Day 0-2006.” The registry record does not report the primary endpoint count and lists 0 analyses. It identifies 9 outcome measures.

Safety summaries are organized into dissection and trauma groups. The record reports participants at risk and affected for serious and other adverse events, deaths in each group, and percentages for several serious-event terms. The groups are not randomized comparator arms, allocation is not stated, and the listed safety summaries do not establish device causation or a comparative treatment effect.